350 results on '"George JE"'
Search Results
52. The Use of Pectoralis Blocks in Breast Surgery: A Practice Advisory and Narrative Review from the Society for Ambulatory Anesthesia (SAMBA).
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Ardon AE, George JE 3rd, Gupta K, O'Rourke MJ, Seering MS, Tokita HK, Wilson SH, Moo TA, Lizarraga I, McLaughlin S, and Greengrass RA
- Subjects
- Analgesics, Analgesics, Opioid, Female, Humans, Mastectomy adverse effects, Pain, Postoperative drug therapy, Pain, Postoperative etiology, Pain, Postoperative prevention & control, Breast Neoplasms surgery, Nerve Block methods, Thoracic Nerves
- Abstract
Although pectoralis (PECS) blocks are commonly used for breast surgery, recommendations regarding the efficacy of these blocks have thus far not been developed by any professional anesthesia society. Given the potential impact of PECS blocks on analgesia after outpatient breast surgery, The Society for Ambulatory Anesthesia (SAMBA) convened a task force to develop a practice advisory on the use of this analgesic technique. In this practice advisory, we compare the efficacy of PECS blocks with systemic analgesia, local infiltration anesthesia, and paravertebral blockade. Our objectives were to advise on two clinical questions. (1) Does PECS-1 and/or -2 blockade provide more effective analgesia for breast-conserving surgery than either systemic analgesics or surgeon-provided local infiltration anesthesia? (2) Does PECS-1 and/or -2 blockade provide equivalent analgesia for mastectomy compared with a paravertebral block (PVB)? Among patients undergoing breast-conserving surgery, PECS blocks moderately reduce postoperative opioid use, prolong time to analgesic rescue, and decrease postoperative pain scores when compared with systemic analgesics. SAMBA recommends the use of a PECS-1 or -2 blockade in the absence of systemic analgesia (Strength of Recommendation A). No evidence currently exists that strongly favors the use of PECS blocks over surgeon-performed local infiltration in this surgical population. SAMBA cannot recommend PECS blocks over surgical infiltration (Strength of Recommendation C). For patients undergoing a mastectomy, a PECS block may provide an opioid-sparing effect similar to that achieved with PVB; SAMBA recommends the use of a PECS block if a patient is unable to receive a PVB (Strength of Recommendation A)., (© 2022. Society of Surgical Oncology.)
- Published
- 2022
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53. Cultivation and characterization of snowbound microorganisms from the South Pole.
- Author
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Hayward MK, Dewey ED, Shaffer KN, Huntington AM, Burchell BM, Stokes LM, Alexander BC, George JE, Kempher ML, Joye SB, Madigan MT, and Sattley WM
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- Antarctic Regions, Fungi, Phylogeny, Bacteria genetics, Ecosystem
- Abstract
Little is known about microbial ecosystems of interior Antarctica, if indeed such ecosystems exist. Although considerable research has assessed microorganisms indigenous to coastal regions of Antarctica, particularly their lakes, ponds, and soils, to our knowledge only one characterized bacterium, a strain of Pseudomonas, has been isolated from South Pole ice or snow. Metagenomic community analyses described in this work and elsewhere reveal that a diversity of bacteria exists in inland polar snows, yet attempts to culture and characterize these microbes from this extreme environment have been few to date. In this molecular and culture-dependent investigation of the microbiology of inland Antarctica, we enriched and isolated two new strains of bacteria and one strain of yeast (Fungi) from South Pole snow samples. The bacteria were of the genera Methylobacterium and Sphingomonas, and the yeast grouped with species of Naganishia (class Tremellocytes). In addition to phylogenetic analyses, characterization of these isolates included determinations of cell morphology, growth as a function of temperature, salinity tolerance, and carbon and energy source versatility. All organisms were found to be cold-adapted, and the yeast strain additionally showed considerable halotolerance. These descriptions expand our understanding of the diversity and metabolic activities of snowbound microorganisms of interior Antarctica.
- Published
- 2021
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54. Closed reduction of paediatric forearm fractures: nitrous oxide versus general anaesthetic.
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Chan MK, Cawthorne DP, St George JE, and Little DG
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- Anesthesia, General, Child, Forearm, Humans, Nitrous Oxide, Prospective Studies, Retrospective Studies, Anesthetics, General, Radius Fractures diagnostic imaging, Radius Fractures surgery, Ulna Fractures
- Abstract
Background: Nitrous oxide with intranasal fentanyl is safe and effective in performing closed reduction of paediatric forearm fractures; however, the difference in outcome when compared to those performed under general anaesthesia (GA) is unclear. We aim to compare the outcomes of closed reduction of paediatric forearm fractures under nitrous oxide versus GA., Methods: This retrospective study based on a prospective change in protocol reviewed the medical records and radiographs of patients with forearm fractures who presented to a tertiary paediatric centre, and who subsequently underwent closed reduction under either nitrous or GA. Data on patient demographics, type and site of fracture and the method of casting were collected. The primary outcomes were loss of reduction, the need for repeat intervention and the rate of complications., Results: There were 301 and 362 patients in the nitrous and GA groups respectively. The overall re-intervention rate was 7.6% in the nitrous group versus 5.0% in the GA group (P = 0.155). There was no significant difference in loss of reduction which involved 9.0% in the nitrous group and 11.3% in the GA group (P = 0.320). There was no significance difference in overall complications. Nausea and vomiting comprised the majority of adverse events., Conclusion: Closed reduction of paediatric forearm fractures performed under nitrous oxide with intranasal fentanyl is safe, effective and achieves comparable re-intervention rates and adverse events to those performed under GA in the operating theatre., (© 2020 Royal Australasian College of Surgeons.)
- Published
- 2020
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55. Esketamine Nasal Spray Plus Oral Antidepressant in Patients With Treatment-Resistant Depression: Assessment of Long-Term Safety in a Phase 3, Open-Label Study (SUSTAIN-2).
- Author
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Wajs E, Aluisio L, Holder R, Daly EJ, Lane R, Lim P, George JE, Morrison RL, Sanacora G, Young AH, Kasper S, Sulaiman AH, Li CT, Paik JW, Manji H, Hough D, Grunfeld J, Jeon HJ, Wilkinson ST, Drevets WC, and Singh JB
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- Administration, Intranasal, Administration, Oral, Adolescent, Adult, Aged, Antidepressive Agents administration & dosage, Cognition drug effects, Drug Therapy, Combination, Female, Humans, Ketamine administration & dosage, Ketamine adverse effects, Male, Middle Aged, Nasal Sprays, Young Adult, Antidepressive Agents therapeutic use, Depressive Disorder, Treatment-Resistant drug therapy, Ketamine therapeutic use
- Abstract
Objective: To evaluate long-term safety and efficacy of esketamine nasal spray plus a new oral antidepressant (OAD) in patients with treatment-resistant depression (TRD)., Methods: This phase 3, open-label, multicenter, long-term (up to 1 year) study was conducted between October 2015 and October 2017. Patients (≥ 18 years) with TRD (DSM-5 diagnosis of major depressive disorder and nonresponse to ≥ 2 OAD treatments) were enrolled directly or transferred from a short-term study (patients aged ≥ 65 years). Esketamine nasal spray (28-mg, 56-mg, or 84-mg) plus new OAD was administered twice a week in a 4-week induction (IND) phase and weekly or every-other-week for patients who were responders and entered a 48-week optimization/maintenance (OP/MAINT) phase., Results: Of 802 enrolled patients, 86.2% were direct-entry and 13.8% were transferred-entry; 580 (74.5%) of 779 patients who entered the IND phase completed the phase, and 150 (24.9%) of 603 who entered the OP/MAINT phase completed the phase. Common treatment-emergent adverse events (TEAEs) were dizziness (32.9%), dissociation (27.6%), nausea (25.1%), and headache (24.9%). Seventy-six patients (9.5%) discontinued esketamine due to TEAEs. Fifty-five patients (6.9%) experienced serious TEAEs. Most TEAEs occurred on dosing days, were mild or moderate in severity, and resolved on the same day. Two deaths were reported; neither was considered related to esketamine. Cognitive performance generally either improved or remained stable postbaseline. There was no case of interstitial cystitis or respiratory depression. Treatment-emergent dissociative symptoms were transient and generally resolved within 1.5 hours postdose. Montgomery-Åsberg Depression Rating Scale total score decreased during the IND phase, and this reduction persisted during the OP/MAINT phase (mean [SD] change from baseline of respective phase to endpoint: IND, -16.4 [8.76]; OP/MAINT, 0.3 [8.12])., Conclusions: Long-term esketamine nasal spray plus new OAD therapy had a manageable safety profile, and improvements in depression appeared to be sustained in patients with TRD., Trial Registration: ClinicalTrials.gov identifier: NCT02497287., (© Copyright 2020 Physicians Postgraduate Press, Inc.)
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- 2020
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56. Drop impact on thin powder layers: pattern formation by air entrapment.
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Sharma M, Gopu M, George JE, Gupta S, and Mampallil D
- Abstract
Impact of drops on thin powder layers displaces the powder particles radially outward producing shallow craters with thick rims, for example, as observed on dust layers on the floor. Here, we report that the patterns formed on thin powder layers by drop impact are not limited to such crater-like ones. Instead, depending upon the layer properties, disc or disc-plus-ring shaped patterns are formed at the impact point. We show that air entrapment and micro-bubble formation during the drop impact result in the formation of such patterns. Based on high-speed imaging, scaling analyses, and measurements with various liquids and powder layers, we propose a mechanism for the formation of such patterns. The phenomenon that we report can open further investigations on drop impact on the granular matter.
- Published
- 2020
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57. Learning from those who have gone before: strengthening the rural allied health workforce in Aotearoa New Zealand.
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George JE, Larmer PJ, and Kayes N
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- Adult, Female, Humans, Male, New Zealand, Personnel Selection methods, Rural Population statistics & numerical data, Young Adult, Allied Health Occupations education, Allied Health Occupations statistics & numerical data, Career Choice, Health Personnel education, Health Workforce statistics & numerical data, Rural Health education, Rural Health statistics & numerical data
- Abstract
Context and issues: The pipeline for the allied health, scientific and technical workforce of Aotearoa New Zealand is under growing pressure, with many health providers finding recruitment and retention increasingly difficult. For health providers in rural settings, the challenges are even greater, with fewer applicants and shorter tenures. As the health needs of rural communities increase, along with expectations of uptake of technologies and the Ministry of Health's strategy to ensure care is provided closer to home, being able to retain and upskill the diminishing workforce requires new ways of thinking. Lessons learned: Understanding the activity that has been undertaken by medical and nursing workforces in New Zealand and abroad, as well as the work of the Australian allied health workforce provides context and opportunities for New Zealand. The challenge is for educators, professional bodies, the Ministry of Health and health providers to develop new ways of thinking about developing a rural workforce for the allied health scientific and technical professions.
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- 2019
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58. Exploring the Tripartite Influence Model of body dissatisfaction in postpartum women.
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Lovering ME, Rodgers RF, George JE, and Franko DL
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- Adult, Female, Humans, Young Adult, Body Image psychology, Feeding and Eating Disorders psychology, Postpartum Period psychology
- Abstract
Pregnancy and childbirth result in dramatic changes in a woman's body shape, which can be associated with body image concerns. To date, however, little is known about how sociocultural factors may influence body dissatisfaction in postpartum women. This study aimed to test a sociocultural model of body image and eating concerns among a sample of postpartum women. A sample of N=474 women, mean (SD) age=30.6 (4.8), having given birth during the last year, completed an online survey and reported on sociocultural pressures from media, peers, family and partners, thin-ideal internalization, appearance comparison, body dissatisfaction, and psychological functioning. Structural equation modeling analyses revealed a good fit to the data, χ
2 (49)=220.20, p<.001, RMSEA=.086, CFI=.93. Findings suggest that women experience strong sociocultural pressures to attain unrealistic body shapes/sizes during the post-pregnancy period, contributing to their body image concerns., (Copyright © 2017 Elsevier Ltd. All rights reserved.)- Published
- 2018
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59. Images in anesthesiology: Severe posterior thigh abscess as a complication of popliteal sciatic nerve catheter.
- Author
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Maheshwari A, George JE 3rd, Esa WA, Turan A, and Mounir-Soliman L
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- Abscess surgery, Anesthesiology, Female, Humans, Middle Aged, Nerve Block instrumentation, Staphylococcal Infections surgery, Staphylococcus aureus isolation & purification, Thigh innervation, Thigh surgery, Abscess microbiology, Nerve Block adverse effects, Sciatic Nerve microbiology, Staphylococcal Infections microbiology, Thigh microbiology
- Published
- 2013
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60. First report of fipronil resistance in Rhipicephalus (Boophilus) microplus of Mexico.
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Miller RJ, Almazán C, Ortíz-Estrada M, Davey RB, George JE, and De León AP
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- Animals, Coumaphos, Esterases genetics, Mexico, Mutation, Permethrin, Pyrazoles, Sodium Channels genetics, Toluidines, Acaricides, Drug Resistance, Rhipicephalus genetics
- Abstract
Five strains of Rhipicephalus (Boophilus) microplus collected from Tamaulipas Mexico were tested for resistance against several classes of acaricides commonly used. All were resistant to fipronil. Four of five were co-resistant to permethrin and coumaphos in addition to being resistant to fipronil. One strain, El Zamora was found multi-resistant to permethrin, coumaphos, fipronil, and amitraz. Selection with fipronil for 3 generations produced a resistance ratio of 8.3 and 9.4 at the LC(50) and the LC(99) estimates, respectively. Permethrin resistance in El Zamora was possibly linked to elevated esterase (CZEST9) and could be a contributing factor of resistance to fipronil. The implications of resistance for the control of the southern cattle tick in the future are discussed., (Published by Elsevier B.V.)
- Published
- 2013
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61. Efficacy of amitraz-impregnated collars on white-tailed deer (Artiodactyla: Cervidae) in reducing free-living populations of lone star ticks (Acari: Ixodidae).
- Author
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Pound JM, Lohmeyer KH, Davey RB, Miller JA, and George JE
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- Animals, Population Density, Deer parasitology, Insect Repellents administration & dosage, Ixodidae, Tick Control, Toluidines administration & dosage
- Abstract
Over a 7 yr period, we monitored the effect of a commercially available, amitraz impregnated anti-tick collar in controlling free-living populations of lone star ticks, Amblyomma americanum (L.) when manually fitted around necks of white-tailed deer, Odocoileus virginianus (Zimmermann). Study animals in treatment and control groups were confined in 38.8 ha game-fenced and densely vegetated treatment plots in South Texas. Tick densities during years 1 and 7 served as untreated pre- and posttreatment comparisons and treatments occurred during years 2 through 5. Reductions in tick densities in the treatment plot were compared against tick densities in a control plot having similar vegetation and numbers of untreated deer. During years of treatment, indices of control pressure ranged from 18.2 to 82.6 for nymphs and 16.9-78.7 for adults, and efficacy, expressed as percentage control during the final year of treatment, was 77.2 and 85.0%, respectively, for nymphal and adult ticks. These data show that acaricidal collar treatments provide efficacies very similar to those achieved with the existing ivermectin-medicated bait and '4-Poster' topical treatment technologies to control ticks feeding on wild white-tailed deer.
- Published
- 2012
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62. Recent advances in epidural analgesia.
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Bauer M, George JE 3rd, Seif J, and Farag E
- Abstract
Neuraxial anesthesia is a term that denotes all forms of central blocks, involving the spinal, epidural, and caudal spaces. Epidural anesthesia is a versatile technique widely used in anesthetic practice. Its potential to decrease postoperative morbidity and mortality has been demonstrated by numerous studies. To maximize its perioperative benefits while minimizing potential adverse outcomes, the knowledge of factors affecting successful block placement is essential. This paper will provide an overview of the pertinent anatomical, pharmacological, immunological, and technical aspects of epidural anesthesia in both adult and pediatric populations and will discuss the recent advances, the related rare but potentially devastating complications, and the current recommendations for the use of anticoagulants in the setting of neuraxial block placement.
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- 2012
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63. Efficacy of spinosad against acaricide-resistant and -susceptible Rhipicephalus (Boophilus) microplus and acaricide-susceptible Amblyomma americanum and Dermacentor variabilis.
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Miller RJ, White WH, Davey RB, George JE, and Perez de Leon A
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- Animals, Dose-Response Relationship, Drug, Drug Combinations, Drug Resistance, Female, Acaricides pharmacology, Ixodidae drug effects, Macrolides pharmacology
- Abstract
Various acaricide-resistant strains of Rhipicephalus (Boophilus) microplus, representative of the major resistance mechanisms found in Mexico and Brazil, were exposed to spinosad using the Food and Agriculture Organization of the United Nations larval packet test and adult immersion test (AIT). Larvae of all strains tested were found to be susceptible to spinosad. Conversely, spinosad did not show toxic activity toward engorged females used in the AIT. In vitro tests against larvae, nymphs, and adults of acaricide-susceptible Amblyomma americanum and Dermacentor variabilis revealed differences in activity that were dependent on tick species and parasitic life stage. Spinosad seemed to be a viable alternative to current acaricides available for tick control in the species tested. The larval packet test should be used for future monitoring of resistance, as the AIT did not provide useful information with this chemical. The potential benefit for the use of spinosad in integrated pest management or eradication programs is discussed.
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- 2011
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64. Evidence for role of white-tailed deer (Artiodactyla: Cervidae) in epizootiology of cattle ticks and southern cattle ticks (Acari: Ixodidae) in reinfestations along the Texas/Mexico border in south Texas: a review and update.
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Pound JM, George JE, Kammlah DM, Lohmeyer KH, and Davey RB
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- Animals, Cattle, Mexico epidemiology, Texas epidemiology, Tick Infestations epidemiology, Deer, Ixodidae physiology, Tick Infestations veterinary
- Abstract
From 1907 when the fever tick eradication campaign began until 1933, the tick eradication methods of dipping cattle in an acaricide or "pasture vacation" were enormously successful in eradicating southern cattle ticks [Rhipicephalus (Boophilus) microplus (Canestrini)], until failures began to occur in some areas of Florida. Regarding the failures in Florida, the consensus was that populations of white-tailed deer [Odocoileus virginianus (Zimmermann)] infested with southern cattle ticks were responsible. After numerous deer in several counties were killed, eradication was achieved in Florida. As in Florida, in Texas increasing numbers of failures of the pasture vacation approach to tick eradication from the 1970s to the present are known to be related to the abundance of white-tailed deer and perhaps other wild ungulate species. A sizable body of evidence confirms the hypothesis that white-tailed deer support the dispersal and maintenance of both cattle ticks [Rhipicephalus (Boophilus) annulatus (Say)] and southern cattle ticks (cattle fever ticks) within the permanent quarantine or buffer zone in South Texas along the Rio Grande, as well as in the so-called free ("cattle fever tick-free") area north and east of the buffer zone and extending to the east coast of the United States. As of August 2009, in addition to the permanent quarantine zone of approximately 2233 km2, three temporary preventative or blanket quarantines were established. Currently, only two methodologies exist to control ticks feeding on white-tailed deer: (1) a systemic treatment method involving dispersal of ivermectin-medicated corn, Zea mays L.; and (2) two topical treatment methods, '4-poster' deer treatment bait stations and '2-poster' deer treatment feeder adapters, both of which passively apply topically active acaricide to deer for the eradication of populations of cattle fever tick associated with white-tailed deer. This study presents and summarizes confirmational support for the role of white-tailed deer derived from historical accounts, circumstantial evidence from review of recent infestations, and cattle fever tick infestations on white-tailed deer that were live-captured and examined specifically for cattle fever ticks.
- Published
- 2010
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65. Effects of photoperiod on reproduction, nymphal developmental timing, and diapause in Amblyomma maculatum (Acari: Ixodidae).
- Author
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Lohmeyer KH, Pound JM, and George JE
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- Animals, Female, Ixodidae growth & development, Molting, Nymph growth & development, Oviposition, Reproduction physiology, Time Factors, Ixodidae physiology, Photoperiod
- Abstract
Female engorgement weight, oviposition, and molting times of larvae and nymphs of Amblyomma maculatum Koch (Acari: Ixodidae) were studied at various photoperiods under constant humidity and temperature in the laboratory. Ticks were held at photoperiods of 0:24, 10:14, 12:12, or 14:10 (L:D) h from egg through unfed nymphal stage and then at either the same or a different regime from fed nymphs to adults. No significant effects were observed on oviposition, female engorgement weights, survival, or molting time to unfed nymphs. Nymphal molting times were significantly shorter at the short-day regime (10:14) during the larval stage and 12:12 during the nymphal stage compared with those held at either 14:10 during both life periods or at 0:24 during both life periods. Longer molting times also were observed in ticks held at 12:12 during the larval phase and either 10:14, 12:12, or 0:24 during the nymphal phase compared with 14:10 during both life periods or 0:24 during both life periods. Ticks held at 10:14 during the larval phase and at 0:24 or 10:14 had longer molting times compared with those at 14:10 or 0:24 during both life periods. No differences in survival to either nymphal or adult stages were observed at any regime, and at day 25 no individuals were observed to be in developmental diapause. This study demonstrates that developmental diapause does not seem to be photoperiodically induced in fed nymphal A. maculatum in the laboratory.
- Published
- 2009
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66. The United States Department Of Agriculture Northeast Area-wide Tick Control Project: history and protocol.
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Pound JM, Miller JA, George JE, and Fish D
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- Acaricides standards, Animals, Arachnid Vectors microbiology, Humans, Ixodes microbiology, Mid-Atlantic Region, New England, Tick Infestations prevention & control, United States, United States Department of Agriculture, Acaricides administration & dosage, Deer parasitology, Lyme Disease prevention & control, Tick Control methods, Tick Infestations veterinary
- Abstract
The Northeast Area-wide Tick Control Project (NEATCP) was funded by the United States Department of Agriculture (USDA) as a large-scale cooperative demonstration project of the USDA-Agricultural Research Service (ARS)-patented 4-Poster tick control technology (Pound et al. 1994) involving the USDA-ARS and a consortium of universities, state agencies, and a consulting firm at research locations in the five states of Connecticut (CT), Maryland (MD), New Jersey (NJ), New York (NY), and Rhode Island (RI). The stated objective of the project was "A community-based field trial of ARS-patented tick control technology designed to reduce the risk of Lyme disease in northeastern states." Here we relate the rationale and history of the technology, a chronological listing of events leading to implementation of the project, the original protocol for selecting treatment, and control sites, and protocols for deployment of treatments, sampling, assays, data analyses, and estimates of efficacy.
- Published
- 2009
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67. Acaricidal treatment of white-tailed deer to control Ixodes scapularis (Acari: Ixodidae) in a New York Lyme disease-endemic community.
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Daniels TJ, Falco RC, McHugh EE, Vellozzi J, Boccia T, Denicola AJ, Pound JM, Miller JA, George JE, and Fish D
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- Analysis of Variance, Animal Feed, Animals, Arachnid Vectors growth & development, Endemic Diseases prevention & control, Geographic Information Systems, Humans, New York, Tick Control statistics & numerical data, Tick Infestations prevention & control, Zea mays, Acaricides administration & dosage, Deer parasitology, Ixodes growth & development, Lyme Disease prevention & control, Tick Control methods, Tick Infestations veterinary
- Abstract
The efficacy of topically treating white-tailed deer with an acaricide was evaluated in a Lyme disease-endemic community of southern New York State. Twenty-four 4-Poster feeders were placed in a 5.2 km(2) treatment area in Bedford, NY, while a site in Lewisboro, NY, 4.8 km distant, served as control. Treatment periods ran from 15 September to 15 December each fall from 1997 to 2001, and from 15 March to 15 May each spring from 1998 to 2002. Corn consumption averaged 15,779 kg in fall sessions and 9054 kg in spring sessions, and a mean of 89.6% of deer in the study area showed evidence of using the feeders. Deer densities, estimated by aerial snow counts, averaged 22 and 28 deer per km(2) in Bedford and Lewisboro, respectively, over a 3-year period. Significant reductions in tick numbers on deer captured in the treatment area were noted in fall 1999 compared to deer captured at the control site. Drag sampling for nymphal host-seeking ticks indicated 63.6% control in 2001, which dropped to 54.8% the following year, but reached 80% in 2003. Higher-than-normal acorn production in 2001 that likely caused a drop in deer visitation to the feeders may have reduced efficacy against larval ticks in 2002. The 4-Poster effectively reduced the density of Ixodes scapularis, though the level of control is dependent on environmental factors that affect feeding behavior of white-tailed deer.
- Published
- 2009
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68. The impact of 4-Poster deer self-treatment devices at three locations in Maryland.
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Carroll JF, Hill DE, Allen PC, Young KW, Miramontes E, Kramer M, Pound JM, Miller JA, and George JE
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- Animal Feed, Animals, Arachnid Vectors, Humans, Insecticides administration & dosage, Linear Models, Lyme Disease prevention & control, Maryland, Population Density, Tick Control statistics & numerical data, Tick Infestations prevention & control, Ticks growth & development, Toluidines administration & dosage, Zea mays, Acaricides administration & dosage, Deer parasitology, Tick Control methods, Tick Infestations veterinary
- Abstract
From 1998-2002 twenty-five deer self-treatment devices (4-Posters), using 2% amitraz, were operated at three locations in Maryland to determine their effectiveness in controlling blacklegged ticks, Ixodes scapularis Say, and lone star ticks, Amblyomma americanum (L.). Each treatment site was approximately 518 ha and paired with a similar site lacking 4-Posters. Locations varied in deer density, tick abundance, and land use. Flagging for host-seeking ticks showed declines in tick populations at all treatment sites compared to control sites by the third year. By 2002, control of I. scapularis nymphs attributable to the 4-Poster intervention at the three sites was 69.0%, 75.8%, and 80%. Control of A. americanum nymphs at the two sites where they occurred was 99.5% and 95.3%. In 2003, the first posttreatment year, control of I. scapularis remained around 2001-2002 levels, but by 2004, an upward trend in nymphal numbers was detectable. Populations of A. americanum showed no increase posttreatment. These results demonstrate that control of these tick species is locally possible with 4-Poster intervention.
- Published
- 2009
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69. Evaluation of the United States Department Of Agriculture Northeast Area-wide Tick Control Project by meta-analysis.
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Brei B, Brownstein JS, George JE, Pound JM, Miller JA, Daniels TJ, Falco RC, Stafford KC 3rd, Schulze TL, Mather TN, Carroll JF, and Fish D
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- Acaricides standards, Animal Feed, Animals, Arachnid Vectors, Humans, Lyme Disease prevention & control, Mid-Atlantic Region, New England, Seasons, Tick Control standards, Tick Control trends, Tick Infestations prevention & control, United States, United States Department of Agriculture, Acaricides administration & dosage, Deer parasitology, Tick Control methods, Tick Infestations veterinary, Ticks growth & development
- Abstract
As part of the Northeast Area-wide Tick Control Project (NEATCP), meta-analyses were performed using pooled data on the extent of tick-vector control achieved through seven concurrent studies, conducted within five states, using U.S. Department of Agriculture "4-Poster" devices to deliver targeted-acaricide to white-tailed deer. Although reductions in the abundance of all life-stages of Ixodes scapularis were the measured outcomes, this study focused on metrics associated with I. scapularis nymphal tick densities as this measure has consistently proven to directly correlate with human risk of acquiring Lyme disease. Since independent tick sampling schemes were undertaken at each of the five environmentally distinct study locations, a meta-analytic approach permitted estimation of a single true control-effect size for each treatment year of the NEATCP. The control-effect is expressed as the annual percent I. scapularis nymphal control most consistent with meta-analysis data for each treatment year. Our meta-analyses indicate that by the sixth treatment year, the NEATCP effectively reduced the relative density of I. scapularis nymphs by 71% on the 5.14 km(2) treatment sites, corresponding to a 71% lower relative entomologic risk index for acquiring Lyme disease.
- Published
- 2009
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70. Topical treatment of white-tailed deer with an acaricide for the control of Ixodes scapularis (Acari: Ixodidae) in a Connecticut Lyme borreliosis hyperendemic Community.
- Author
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Stafford KC 3rd, Denicola AJ, Pound JM, Miller JA, and George JE
- Subjects
- Analysis of Variance, Animal Feed, Animals, Arachnid Vectors growth & development, Borrelia burgdorferi growth & development, Connecticut, Endemic Diseases prevention & control, Humans, Mid-Atlantic Region, Nymph, Rhode Island, Tick Infestations prevention & control, Zea mays, Acaricides administration & dosage, Deer parasitology, Ixodes growth & development, Lyme Disease prevention & control, Tick Control methods, Tick Infestations veterinary
- Abstract
The 4-Poster device for the topical treatment of white-tailed deer, Odocoileus virginianus (Zimmermann), against ticks using the acaricide amitraz, was evaluated in a Lyme borreliosis endemic community in Connecticut. As part of a 5-year project from 1997 to 2002, 21-24 of the 4-Posters were distributed at residential sites in Old Lyme, CT, in a core treatment area of approximately 5.2 km(2) in fall 1997. The 4-Posters were active October to mid-December and March into May, corresponding to the peak periods of activity for adult Ixodes scapularis in this particular area. Corn consumption ranged from 361 to 4789 kg/month for October and November and 696-3130 kg/month during April. Usage of 4-Posters by deer generally was high (>90%), except during acorn masts in fall 1998 and 2001. Amitraz was applied by rollers at the estimated rate of 1.3 g active ingredient/ha/year. The abundance of host-seeking I. scapularis nymphs declined significantly (p < 0.001) in the core treatment area, as compared to a control community in Old Saybrook, CT, through 2004, over the project period from 1998 to 2003, from 9.3/100m(2) to 0.97/100m(2), rising to 1.90/100m(2) in 2004. From 1999 through 2003, there were 46.1%, 49.6%, 63.4%, 64.6%, and 70.2% reductions, respectively, in the nymphal tick population in comparison with the untreated community and initial tick abundance in 1998. Control of I. scapularis adults declined to only 19.1% in 2004; 2 years after the treatment of deer was discontinued. Differences in nymphal tick abundance between the control and core treatment area were significant in 1999 (p = 0.042) and highly significant in 2001 (p < 0.001) and 2002 (p = 0.002). The passive topical application to deer of the acaricide amitraz resulted in a significant decrease in the population of free-living I. scapularis nymphs in the treated core in Connecticut.
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- 2009
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71. The United States Department of Agriculture's Northeast Area-wide Tick Control Project: summary and conclusions.
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Pound JM, Miller JA, George JE, Fish D, Carroll JF, Schulze TL, Daniels TJ, Falco RC, Stafford KC, and Mather TN
- Subjects
- Analysis of Variance, Animal Feed, Animals, Humans, Mid-Atlantic Region, New England, Population Density, Program Evaluation, Surveys and Questionnaires, Tick Control economics, Tick Control standards, Tick Control trends, Tick Infestations prevention & control, United States, United States Department of Agriculture, Zea mays, Acaricides administration & dosage, Deer parasitology, Ixodidae growth & development, Tick Control methods, Tick Infestations veterinary
- Abstract
From 1997 to 2002, the U.S. Department of Agriculture's Northeast Area-wide Tick Control Project used acaricide-treated 4-Poster Deer Treatment Bait Stations in five eastern states to control ticks feeding on white-tailed deer. The objectives of this host-targeted technology were to reduce free-living blacklegged (Ixodes scapularis Say) and lone star (Amblyomma americanum [L.]) tick populations and thereby to reduce the risk of tick-borne disease. During 2002 to 2004, treatments were suspended, and tick population recovery rates were assayed. Subsequently, the major factors that influenced variations in efficacy were extrapolated to better understand and improve this technology. Treatments resulted in significant reductions in free-living populations of nymphal blacklegged ticks at six of the seven sites, and lone star ticks were significantly reduced at all three sites where they were present. During the study, maximal significant (p < or = 0.05) efficacies against nymphal blacklegged and lone star ticks at individual sites ranged from 60.0 to 81.7 and 90.9 to 99.5%, respectively. The major environmental factor that reduced efficacy was the occurrence of heavy acorn masts, which provided an alternative food resource for deer. Although the 4-Poster technology requires 1 or more years to show efficacy, this host-targeted intervention was demonstrated to be an efficacious, economical, safe, and environment-friendly alternative to area-wide spraying of acaricide to control free-living populations of these tick species.
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- 2009
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72. Epizootiology of Babesia bovis and Babesia bigemina in free-ranging white-tailed deer in northeastern Mexico.
- Author
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Cantu-C A, Ortega-S JA, García-Vázquez Z, Mosqueda J, Henke SE, and George JE
- Subjects
- Animal Husbandry methods, Animals, Antibodies, Protozoan blood, Babesia genetics, Babesia immunology, Babesia isolation & purification, Babesiosis epidemiology, Babesiosis parasitology, Cattle, Chi-Square Distribution, Confidence Intervals, DNA, Protozoan blood, DNA, Protozoan isolation & purification, Ecosystem, Female, Fluorescent Antibody Technique, Indirect veterinary, Logistic Models, Mexico epidemiology, Odds Ratio, Polymerase Chain Reaction veterinary, Risk Factors, Seroepidemiologic Studies, Tick Infestations epidemiology, Tick Infestations prevention & control, Tick Infestations veterinary, Babesia bovis genetics, Babesia bovis immunology, Babesia bovis isolation & purification, Babesiosis veterinary, Deer parasitology
- Abstract
Species of Rhipicephalus (Boophilus) ticks are the vectors of babesiosis (cattle fever tick), which are distributed worldwide. White-tailed deer (Odocoileus virginianus) are important secondary hosts for the cattle fever ticks, Rhipicephalus (B.) annulatus and Rhipicephalus (B.) microplus. White-tailed deer are capable of sustaining Boophilus spp. tick populations in the presence or absence of cattle. The objectives of this study were to determine the frequency of Babesia bovis and Babesia bigemina and the prevalence of antibodies to them and identify possible risk factors for bovine babesiosis in white-tailed deer in 3 northeastern states of México. Whole blood and serum samples (n = 457) were collected from white-tailed deer in the states of Coahuila, Nuevo Leon, and Tamaulipas during the spring of 2004. Samples were tested for B. bovis and B. bigemina by nested polymerase chain reaction (n-PCR) (the primers for B. bovis identified the gene Rap-1 and B. bigemina were specific primers) and by an indirect immunofluorescence antibody test (IFAT). A questionnaire was given to each ranch to obtain information about management practices. Logistic regression methods were used to test the association between management factors and the dependent variable of positive n-PCR or IFAT. Nineteen (4.2%) samples were positive to B. bigemina and 6 (1.7%) were positive to B. bovis by n-PCR. Serological testing showed 59.9% (n = 274) of deer sampled were positive to B. bovis and 5.4% (n = 25) were positive to B. bigemina antibodies. The logistic model varied with different dependent variables. With positive n-PCR and B. bigemina as the dependent variable, 3 factors were associated: habitat (presence of brush and exotic grasses; odds ratio (OR), 3.3; 95% confidence interval (CI), 1.3-8.5), grazing system (continuous grazing OR 4.0; CI, 1.3-12.2), and tick treatment frequency (3-4 mo; OR 7.0, CI 1.4-34.3; 5-6 mo; OR, 11.0; CI, 1.9-62.7; > 6 mo; OR, 4.6; CI, 0.9-23.3). These findings suggest that white-tailed deer may act as a reservoir for the 2 bovine Babesia spp. and that white-tailed deer may be important in the epidemiology of babesiosis. However, evidence is not available to support whether white-tailed deer are, or are not, likely to be a host that could complete the transmission cycle of Babesia spp. These results suggest that additional research is needed to demonstrate the importance of white-tailed deer as a Babesia spp. infection source for ticks.
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- 2009
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73. Effect of rainfall exposure immediately after a single dip treatment with coumaphos on the control of Rhipicephalus (Boophilus) microplus (Acari: Ixodidae) on infested cattle.
- Author
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Davey RB, Miller JA, Miller RJ, and George JE
- Subjects
- Animals, Cattle, Cattle Diseases drug therapy, Cattle Diseases parasitology, Coumaphos administration & dosage, Insecticides administration & dosage, Larva, Nymph, Tick Infestations drug therapy, Tick Infestations prevention & control, Cattle Diseases prevention & control, Coumaphos therapeutic use, Insecticides therapeutic use, Rain, Rhipicephalus, Tick Infestations veterinary
- Abstract
Efficacy of a single dip treatment in coumaphos at 0.182% active ingredient was determined against all parasitic stages of Rhipicephalus (Boophilus) microplus (Canestrini) on infested cattle exposed to various levels of rainfall immediately after treatment. One group of calves remained untreated with no exposure to rainfall to serve as a negative control. A second group of cattle treated with coumaphos, but not exposed to rainfall, acted as a positive treated control. Three additional groups of coumaphos-treated cattle were exposed to 14.3, 28.6, and 42.9 mm of rainfall, respectively. In the coumaphos-treated group not exposed to a rainfall, overall mean control (99.2%) was greater and mean female engorgement weight (200 mg), egg mass weight (43 mg), and index of fecundity (IF; 2.90) were all less than any group exposed to rainfall. Although exposure to the lowest level of rainfall (14.3 mm) resulted in substantially greater control (83.7%) with lower mean egg mass weight (65 mg) and IF (62.26) than ticks exposed to 28.6 or 42.9 mm of rainfall, differences were seldom significant (P > 0.05). This suggested that higher levels of rainfall exposure adversely impacted coumaphos efficacy somewhat more than lower levels of rainfall exposure. Control remained >97% against larval ticks regardless of rainfall exposure level; however, against nymphs or adults, dramatic declines in control occurred as a result of exposure to any rainfall. Thus, the movement of coumaphos treated cattle exposed to any level of rainfall would pose a high risk of dispersing viable ticks into uninfested areas.
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- 2009
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74. The effects of global change on the threat of exotic arthropods and arthropod-borne pathogens to livestock in the United States.
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George JE
- Subjects
- Animals, Arthropod Vectors, Arthropods microbiology, United States, Animals, Domestic parasitology, Arthropods pathogenicity
- Abstract
Arthropod-borne diseases are an important part of the group of foreign animal diseases that command attention from federal, state, and local animal health authorities in the United States because of the potential for adverse local and regional animal health impacts and also because of possible losses of export markets. Diseases of concern are listed by the US Animal Health Association and also by the Office International des Epizooties. Global change is causing the emergence of newly recognized diseases and altering enzootic and epizootic circumstances for known disease problems. Selected examples of arthropod-borne diseases of importance are discussed in terms of their potential for introduction, spread, and impact on livestock and human health in the United States.
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- 2008
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75. Prevalence of infectious agents in free-ranging white-tailed deer in northeastern Mexico.
- Author
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Cantu A, Ortega-S JA, Mosqueda J, Garcia-Vazquez Z, Henke SE, and George JE
- Subjects
- Animals, Animals, Wild microbiology, Animals, Wild virology, Brucella immunology, Cattle, Deer virology, Diarrhea Viruses, Bovine Viral immunology, Disease Reservoirs microbiology, Disease Reservoirs virology, Herpesvirus 1, Bovine immunology, Leptospira immunology, Mexico epidemiology, Prevalence, Seroepidemiologic Studies, Antibodies, Bacterial blood, Antibodies, Viral blood, Deer microbiology, Disease Reservoirs veterinary
- Abstract
The objectives of this study were to determine the prevalence of antibodies against brucellosis, leptospirosis, infectious bovine rhinotracheitis virus, and bovine viral diarrhea virus (BVDV) in white-tailed deer (Odocoileus virginianus) in northeastern Mexico. Deer (n=521) were captured from helicopter using a netgun on 15 ranches covering 62,114 ha in the states of Coahuila, Nuevo Leon, and Tamaulipas during spring 2004. The prevalence of antibodies against Leptospira, infectious bovine rhinotracheitis, BVDV, and brucellosis were 5.6, 41.1, 63.5, and 0%, respectively, indicating that white-tailed deer and cattle may share disease agents when cohabiting in northeastern Mexico.
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- 2008
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76. Differential response to diazinon and coumaphos in a strain of Boophilus microplus (Acari: Ixodidae) collected in Mexico.
- Author
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Miller RJ, Li AY, Tijerina M, Davey RB, and George JE
- Subjects
- Acetylcholinesterase metabolism, Animals, Cholinesterase Inhibitors pharmacology, Dose-Response Relationship, Drug, Mexico, Coumaphos pharmacology, Diazinon pharmacology, Insecticide Resistance physiology, Insecticides pharmacology, Ixodidae drug effects
- Abstract
Boophilus microplus, collected from Nuevo Leon, Mexico, were found to be highly resistant to diazinon but not highly resistant to coumaphos, suggesting that different mechanisms of resistance were present in these ticks than other Mexican organophosphate (OP)-resistant ticks reported previously. When exposed to coumaphos and piperonyl butoxide or triphenylphosphate, the LCso estimate was reduced by 3.5- and 6.3-fold, respectively, suggesting that mono-oxygenases and/or esterases were involved in resistance to coumaphos. Additionally, it was determined that this strain had an Acetylycholinesterase (AChe) that was insensitive to the active form of coumaphos, coroxon, taking at least 24 min longer to reach 50% reduction in AChE activity compared with the susceptible strain. When exposed to diazinon, none of the synergists tested significantly lowered the LC50. However, it was determined that it took six times longer to reach 60% inhibition of AChE in the resistant strain compared with the susceptible strain when exposed to the active form of diazinon, diazoxon. Insensitive AChE seems to be very common in OP-resistant B. microplus. The potential benefits for the development of a field-portable AChE inhibition assay kit are discussed.
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- 2008
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77. In vitro and in vivo evaluation of deltamethrin and amitraz mixtures for the control of Rhipicephalus (Boophilus) microplus (Acari: Ixodidae) in New Caledonia.
- Author
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Barré N, Li AY, Miller RJ, Gaïa H, Delathière JM, Davey RB, and George JE
- Subjects
- Animals, Cattle, Dairying, Drug Synergism, Insect Control methods, Insecticides administration & dosage, Insecticides pharmacology, Larva drug effects, New Caledonia, Tick Infestations prevention & control, Tick Infestations veterinary, Time Factors, Cattle Diseases drug therapy, Nitriles administration & dosage, Nitriles pharmacology, Pyrethrins administration & dosage, Pyrethrins pharmacology, Rhipicephalus drug effects, Toluidines administration & dosage, Toluidines pharmacology
- Abstract
Acaricide resistance is a major problem that hinders the control of the tropical cattle tick, Rhipicephalus (Boophilus) microplus (Canestrini), in many parts of the world where cattle production continues to suffer severe economic losses to tick infestation. Deltamethrin and amitraz have been used alone to control R. microplus in New Caledonia for the past decade, and tick populations have developed resistance to both acaricides. A study was conducted to evaluate the effectiveness of deltamethrin and amitraz mixtures, through in vitro laboratory bioassays and in vivo on-animal efficacy trials, for the control of resistant R. microplus on cattle at two dairy farms in New Caledonia. Results of laboratory bioassays using modified larval packet tests (LPT) revealed up to 16.59-fold resistance to deltamethrin, and up to 5.86-fold resistance to amitraz. Significant synergism was observed when amitraz was used as a synergist in deltamethrin bioassays. Amitraz significantly increased deltamethrin toxicity to tick larvae, while deltamethrin was much less effective on amitraz toxicity. Synergism of amitraz by deltamethrin only occurred when the deltamethrin concentration was relatively high. Results of on animal efficacy trials of deltamethrin and amitraz alone and mixtures of both at different concentrations revealed a similar pattern of synergism. Adding amitraz to a deltamethrin formulation led to dramatic increases of percent reduction of both immature and adult ticks. In contrast, adding deltamethrin to an amitraz formulation did not increase control efficacy. Results from this study may lead to the adoption of an acaricide mixture strategy for the control of pyrethroid-resistant R. microplus in New Caledonia and elsewhere.
- Published
- 2008
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78. Genetics and mechanisms of permethrin resistance in the Santa Luiza strain of Boophilus microplus (Acari: Ixodidae).
- Author
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Li AY, Davey RB, Miller RJ, Guerrero FD, and George JE
- Subjects
- Animals, Esterases metabolism, Female, Genotype, Male, Pesticide Synergists pharmacology, Insecticide Resistance genetics, Insecticides pharmacology, Ixodidae drug effects, Ixodidae genetics, Permethrin pharmacology
- Abstract
The Santa Luiza strain of the southern cattle tick, Boophilus microplus (Canestrini) (Acari: Ixodidae), is resistant to both permethrin and amitraz. A study was conducted at the USDA Cattle Fever Tick Research Laboratory in Texas to investigate the genetic basis of permethrin resistance with cross-mating experiments, and to determine the mechanisms of permethrin resistance through synergist bioassays and biochemical analysis of esterase profiles. The Muñoz strain, an acaricide-susceptible reference strain, was used as the susceptible parent and the Santa Luiza strain, originating in Brazil, was used as the resistant parent. The Food and Agriculture Organization larval packet test was used to measure the levels of susceptibility of larvae of the parental strains, F1, backcross, F2, and F3 generations to permethrin. Results of reciprocal crossing experiments suggested that permethrin resistance was inherited as an incomplete recessive trait. There was no significant maternal effect on larval progeny's susceptibility to permethrin in the F1 and subsequent generations. The values of the degree of dominance were estimated at -0.700 and -0.522 for the F1 larvae with resistant and susceptible female parents, respectively. Results of bioassays on larval progeny of the F1 backcrossed with the resistant parent strain and of the F2 generations suggested that one major gene was responsible for permethrin resistance in the Santa Luiza strain. Selection of F3 larvae with either permethrin or amitraz led to significantly increased resistance to both permethrin and amitraz, indicating a close linkage between genes responsible for permethrin and amitraz resistance. The possible involvement of metabolic enzymes in permethrin resistance in the Santa Luiza strain of B. microplus was dismissed by the lack of enhanced synergism by TPP or PBO, as observed in synergist bioassays, as well as by the lack of enhanced esterase activity in the Santa Luiza strain relative to the susceptible strain. The results of this study suggest that other mechanisms, including a possible new sodium channel mutation that is different from the one currently known, may be responsible for permethrin resistance in the Santa Luiza strain of B. microplus.
- Published
- 2008
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79. Efficacy of amitraz applied as a dip against an amitraz-resistant strain of Rhipicephalus (Boophilus) microplus (Acari: Ixodidae) infested on cattle.
- Author
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Davey RB, Miller RJ, and George JE
- Subjects
- Administration, Topical, Animals, Cattle, Dose-Response Relationship, Drug, Female, Insecticides therapeutic use, Larva, Oviposition, Tick Infestations drug therapy, Time Factors, Toluidines therapeutic use, Cattle Diseases drug therapy, Insecticide Resistance, Insecticides pharmacology, Rhipicephalus drug effects, Rhipicephalus physiology, Tick Infestations veterinary, Toluidines pharmacology
- Abstract
Selection pressure with the acaricide, amitraz was applied to a strain of Rhipicephalus (Boophilus) microplus (Canestrini) in 13 out of 18 generations, resulting in a 28.7-fold increase in resistance, indicating a shift in the phenotypic composition of the ticks, from a heterogenous mixture of both susceptible and resistant ticks when selection began to a homogenous composition of predominantly resistant ticks when selection ended. Resistant larvae of the last selected generation were infested on cattle three separate times at 20, 13, and 6 d (7 d intervals) before being dipped in a total immersion vat charged at 0.02, 0.044, and 0.096% active ingredient (AI) amitraz. There was a dose related, though not always significant, response to amitraz whereby each increase in concentration produced increased adverse effects. The number of ticks and index of fecundity (IF) of females recovered from cattle treated at 0.02 and 0.044% AI were not different from that of untreated ticks. However, female weight and egg mass weight of females recovered from cattle treated at 0.044% were lower than untreated females or females treated at 0.02% AI. All measured parameters obtained from ticks recovered from cattle treated at 0.096% AI were significantly lower than the untreated control group, but tick numbers and IF were not different from the other treated groups. At 0.02% AI the level of control was significantly lower (34.6%) than treatment at 0.096% AI (81.2%), while the level of control at 0.044% AI (57.6%) was intermediate between the other treated groups. Therefore, none of the amitraz treatments provided the required 99% control necessary for use in the U.S. Cattle Fever Tick Eradication Program, and the estimated line derived from regression analysis showed that a concentration of ca. 0.2% AI amitraz would be needed to achieve 99% control of the resistant ticks.
- Published
- 2008
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80. Sugar feeding by the aphid parasitoid Binodoxys communis: how does honeydew compare with other sugar sources?
- Author
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Wyckhuys KA, Strange-George JE, Kulhanek CA, Wäckers FL, and Heimpel GE
- Subjects
- Animals, Anthracenes metabolism, Chromatography, High Pressure Liquid, Female, Longevity, Aphids, Carbohydrates, Feeding Behavior physiology, Wasps physiology
- Abstract
Parasitoids commonly forage in agricultural settings where the predominant sugar source is homopteran honeydew. The aphidiine braconid, Binodoxys communis, is an Asian parasitoid currently being released against the soybean aphid, Aphis glycines, in North American soybean fields. We conducted a number of laboratory experiments evaluating the quality of A. glycines honeydew as a sugar source for this parasitoid. Wasps readily fed on droplets of A. glycines honeydew, honey and 50% sucrose solution, but the length of feeding bouts on honey was significantly longer than on the other foods. Parasitoids lived significantly longer when fed honey or sucrose than honeydew, while starved wasps had the shortest lifespan. At 21+/-1 degrees C and 25+/-5% R.H., male B. communis that were fed honey lived for a maximum of 14 days, while females lived up to 20 days. Honeydew-fed wasps of both sexes lived approximately 3 days on average, which was 2-3 times longer than when they were only allowed access to water. Anthrone tests of whole insects showed that total sugar and glycogen levels of honey or sucrose-fed individuals were consistently higher than those fed honeydew or water. The glycogen levels of honeydew-fed wasps increased significantly after one day of feeding. HPLC analyses revealed that B. communis readily assimilates A. glycines honeydew oligosaccharides such as erlose, while others (e.g., raffinose) did not degenerate. Raffinose was present in much higher amounts in honeydew-fed wasps than in wasps fed other diets, so this sugar could be used as a 'signature' sugar for this species. Honeydew-fed wasps also had significantly lower fructose/(fructose+glucose) ratios than those from other diet treatments. Although A. glycines honeydew might be the main carbohydrate source within a soybean field, other sugar sources such as floral nectar appear to be more optimal foods for B. communis from a physiological standpoint. We discuss the results from the perspective of classical biological control of the soybean aphid in North America.
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- 2008
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81. Online in situ analysis of selected semi-volatile organic compounds in water by automated microscale solid-phase extraction with large-volume injection/gas chromatography/mass spectrometry.
- Author
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Li Y, George JE, and McCarty CL
- Subjects
- Automation, Robotics, Sensitivity and Specificity, Volatilization, Gas Chromatography-Mass Spectrometry methods, Organic Chemicals analysis, Water chemistry
- Abstract
A fully automated analytical method was developed for the online in situ analysis of selected semi-volatile organic compounds in water. The method used a large-volume injection/gas chromatography/mass spectrometry coupled with a fully automated microscale solid-phase extraction technique, which was based on x-y-z robotic techniques. Water samples were extracted by using a 96-well solid-phase extraction plate. For most analytes included in this study, the obtained linear calibrations ranged from 0.05 to 5.0 microg/L with correlation coefficients of 0.996-1.000, the method detection limits were less than 0.1 microg/L, and the relative recoveries were in the range of 70-120% with a relative standard deviation of less than 15% for fortified reagent water samples. The applications to chlorinated tap water, well water, and river water have been validated. The obtained results were similar to those resulting from fortified reagent water samples for all analytes except metribuzin, bromacil, aldrin, and methoxychlor. Matrix effects were observed for these analytes. In general, this fully automated analytical method was rugged, reliable, and easy to operate, and was capable of providing real-time data to water treatment and distribution systems as well as water reservation and protection systems. In addition, the method could reduce the analytical costs associated with sample collection, transportation, storage, and preparation.
- Published
- 2007
- Full Text
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82. Acaricide resistance and synergism between permethrin and amitraz against susceptible and resistant strains of Boophilus microplus (Acari: Ixodidae).
- Author
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Li AY, Chen AC, Miller RJ, Davey RB, and George JE
- Subjects
- Animals, Biological Assay, Drug Synergism, Gene Frequency, Insecticide Resistance genetics, Sodium Channels genetics, Insecticides, Permethrin, Pesticide Synergists, Rhipicephalus genetics, Toluidines
- Abstract
The control of the southern cattle tick, Boophilus microplus (Canestrini), in Mexico and many other countries relies on chemical acaricides. Boophilus microplus has developed resistance to all major classes of acaricides in recent years. To gain a better understanding of the resistance and to develop resistance management strategies that benefit both Mexican ranchers and USDA's cattle fever tick eradication program (CFTEP), the authors used larval bioassay techniques to determine levels of resistance to permethrin and amitraz and then evaluated synergism between these two acaricides in one susceptible laboratory tick strain and four resistant strains originating from Mexico and Brazil. To examine mechanisms of resistance to permethrin in these strains, the frequency of a mutated sodium channel gene was determined using a PCR assay. The tick strains from Mexico and Brazil demonstrated 49.4- to over 672.2-fold resistance to permethrin, and up to 94.5-fold resistance to amitraz. While the San Roman strain from Mexico was the most permethrin-resistant strain, the Santa Luiza strain from Brazil was the most amitraz-resistant strain. A significant correlation was found between the permethrin resistance ratio and the allelic frequency of the sodium channel mutation. Significant synergism between permethrin and amitraz was found when one acaricide was tested in the presence of another. Synergism ratios ranged from 1.5 to 54.9 when amitraz was tested as a synergist for permethrin. Similar synergism ratios were obtained when permethrin was tested as a synergist for amitraz. Permethrin caused virtually no mortality in the San Roman strain, even at the highest concentration (3294 microg cm(-2)). Adding amitraz (11.0 microg cm(-2)) to permethrin led to a dramatic increase in larval mortality, even at very low concentrations of permethrin., (2007 Society of Chemical Industry)
- Published
- 2007
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83. Characterization of permethrin-resistant Boophilus microplus (Acari: Ixodidae) collected from the state of Coahuila, Mexico.
- Author
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Miller RJ, Rentaria JA, Martinez HQ, and George JE
- Subjects
- Animals, Arachnid Vectors genetics, Cattle, Coumaphos, Female, Homozygote, Mexico, Sodium Channels genetics, Toluidines, Arachnid Vectors drug effects, Insecticide Resistance genetics, Insecticides, Ixodidae genetics, Permethrin
- Abstract
Southern cattle ticks, Boophilus microplus (Canestrini) (Acari: Ixodidae), collected in Coahuila, Mexico, were determined to be resistant to permethrin. Discriminating concentration (DC) tests at the LC99 and 2X the LC99 of susceptible ticks produced 0 and 0.5% mortality, respectively, for permethrin. However, measured mortalities for coumaphos and amitraz acaricides were within the expected ranges. Polymerase chain reaction analysis of this strain detected a 99% frequency of homozygous resistant individuals in this strain.
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- 2007
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84. Immunologic and molecular identification of Babesia bovis and Babesia bigemina in free-ranging white-tailed deer in northern Mexico.
- Author
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Cantu A, Ortega-S JA, Mosqueda J, Garcia-Vazquez Z, Henke SE, and George JE
- Subjects
- Animals, Antibodies, Protozoan blood, Arachnid Vectors parasitology, Babesia bovis immunology, Babesia bovis isolation & purification, Babesiosis epidemiology, Babesiosis parasitology, DNA, Protozoan analysis, Disease Reservoirs veterinary, Fluorescent Antibody Technique, Indirect veterinary, Mexico epidemiology, Polymerase Chain Reaction veterinary, Species Specificity, Tick Infestations veterinary, Ticks parasitology, Babesia immunology, Babesia isolation & purification, Babesiosis veterinary, Deer parasitology
- Abstract
The suitability of white-tailed deer (Odocoileus virginianus) as hosts for the cattle ticks Rhipicephalus (Boophilus) microplus and Rhipicephalus (Boophilus) annulatus, has been well documented. These ticks have a wide host range, and both transmit Babesia bovis and Babesia bigemina, the agents responsible for bovine babesiosis. Although this disease and its vectors have been eradicated from the United States and some states in northern Mexico, it still is a problem in other Mexican states. It is not known if wild cervids like white-tailed deer can act as reservoirs for bovine babesiosis. The purpose of this study was to determine if B. bovis and B. bigemina or antibodies against them occur in white-tailed deer in the states of Nuevo Leon and Tamaulipas, Mexico. Twenty blood samples from white-tailed deer from two ranches were collected and tested with a nested polymerase chain reaction (nested PCR) and indirect immunofluorescence antibody test (IFAT) for B. bovis and B. bigemina. Eleven samples were positive for B. bigemina and four for B. bovis by nested PCR; amplicon sequences were identical to those reported in GenBank for B. bovis (Rap 1) and B. bigemina. Results of the IFA test showed the presence of specific antibodies in serum samples. This is the first report of the presence of B. bovis and B. bigemina in white-tailed deer using these techniques and underscores the importance of cervids as possible reservoirs for bovine babesiosis.
- Published
- 2007
- Full Text
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85. Detection of Babesia bigemina infection in strains of Rhipicephalus (Boophilus) microplus collected from outbreaks in south Texas.
- Author
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Guerrero FD, Bendele KG, Davey RB, and George JE
- Subjects
- Animals, Arachnid Vectors parasitology, Babesia classification, Cattle, Cattle Diseases transmission, Texas epidemiology, Babesia isolation & purification, Babesiosis transmission, Cattle Diseases parasitology, Disease Outbreaks veterinary, Rhipicephalus parasitology
- Abstract
The sudden death of several cattle infested experimentally with Rhipicephalus (Boophilus) microplus led to a clinical investigation into the reasons for the unexpected mortality. Microscopic evidence for Babesia bigemina infection was found in blood smears from the affected animals and a PCR assay was designed to detect the presence of B. bigemina and Babesia bovis in all R. microplus strains received and propagated at the laboratory. The assay utilizes a nested PCR approach with the first PCR amplifying a well-conserved segment from the Babesia 18S ribosomal RNA gene followed by a nested PCR with Babesia species-specific primers and annealing temperatures enabling amplification of the 18S ribosomal RNA gene fragment specific to either B. bigemina or B. bovis. DNA from groups of 50 larvae was extracted using a rapid DNA preparation protocol, which consisted of grinding the frozen tick larvae in PCR buffer and boiling the mixture for 5min. The assay sensitivity allowed for the detection of the equivalent of a single infected tick larva. R. microplus eggs were also analyzed, but yolk protein viscosity created inconsistent results with the crush and boil DNA isolation protocol, necessitating the use of a more extensive proteinase K digestion-based DNA purification method. We detected the presence of B. bigemina in all strains of R. microplus currently reared at the laboratory and 4 of 26 strains collected from infestation outbreaks in Texas by the U.S. Cattle Fever Tick Eradication Program.
- Published
- 2007
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- View/download PDF
86. Efficacy of a single doramectin injection against adult female Boophilus microplus (Acari: Ixodidae) in the final stages of engorgement before detachment.
- Author
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Davey RB, Miller JA, George JE, and Klavons JA
- Subjects
- Animals, Cattle, Cattle Diseases parasitology, Cattle Diseases prevention & control, Female, Injections, Subcutaneous veterinary, Insecticides blood, Insecticides pharmacology, Ivermectin administration & dosage, Ivermectin blood, Ivermectin pharmacology, Random Allocation, Tick Infestations drug therapy, Tick Infestations prevention & control, Time Factors, Cattle Diseases drug therapy, Insecticides administration & dosage, Ivermectin analogs & derivatives, Ixodidae drug effects, Tick Infestations veterinary
- Abstract
The efficacy of injectable doramectin applied at 200 microg/kg was evaluated against adult female Boophilus microplus (Canestrini) (Acari: Ixodidae) in the later stages of engorgement before detachment. Lethal levels of doramectin in the serum of treated cattle (9.7-36.6 ppb) were reached and sustained within 24 h after treatment. However, treatment at 19 or 20 d postinfestation allowed greater tick survival and reproductive capability (IF) than at 18 d postinfestation, indicating that a significant portion of the ticks were able to engorge and detach before obtaining a lethal dose of doramectin. Thus, treatment at 18 d after infestation provided significantly higher overall control (99.5%) than treatment at 19 or 20 d postinfestation (95.8 and 89.1%, respectively). Analysis of control on a daily basis demonstrated that treatment at 18 d postinfestation provided > 99% on each day of the evaluation. Conversely, treatment at 19 or 20 d postinfestation produced levels of control ranging from 22.6 to 85.6% during the first 2 d of female detachment, and > or = 99% control was not achieved until after the fourth day of female detachment, where it remained throughout the study. Therefore, application of injectable doramectin at < or = 18 d after tick infestation was the only treatment regime considered acceptable for use in the U.S. Boophilus Eradication Program. Treatment intervals > 18 d postinfestation could pose a substantial risk of dispersing viable ticks to tick-free areas outside the permanent quarantine zone that has been established along the Texas-Mexico border.
- Published
- 2007
87. A comparison of three bioassay techniques to determine amitraz susceptibility in Boophilus microplus (Acari: Ixodidae).
- Author
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Miller RJ, Davey RB, White WH, and George JE
- Subjects
- Animals, Larva, Lethal Dose 50, Biological Assay methods, Insecticides, Ixodidae, Toluidines
- Abstract
The ability of the Miller, Soberanes, and White bioassay techniques to describe amitraz susceptibility in three different strains of Boophilus microplus (Canestrini) (Acari: Ixodidae) was compared. For a susceptible strain, all techniques adequately described amitraz susceptibility by producing a full range of mortality that corresponded with increasing concentration of amitraz. However, when resistant strains were evaluated, only the Miller and the Soberanes techniques adequately estimated the dose-response relationship. Lethal concentrations were not precisely estimated when all the data were included in the analyses for every strain and technique tested. Better estimates were obtained when subsets of data around the range of interest were subjected to probit analysis. For the Soberanes technique, the slope of the probit regression was steeper for the Brazilian resistant and Texan susceptible strains compared with the heterozygous Mexican strain. The pattern was different when the same strains were tested with the Miller technique. The slopes of the regressions for the Mexican and the Texan strains did not differ significantly, but the Brazilian strain had a steeper slope than the other strains. Resistance ratios were much greater when the Soberanes technique was used than when the Miller technique was used on the same strains. However, neither technique produced enough separation between susceptible and resistant strains to develop a traditional discriminating dose (DD) test that required a concentration of 2x LC99.9 estimate. A DD test at the LC99 would be possible for both techniques. We discuss the strengths and weaknesses of the three techniques, including potential improvements to the White technique. The White technique has the greatest potential to determine the mechanisms of amitraz resistance in detailed synergist studies. Currently, only the Miller method can fulfill this task. The Miller and Soberanes techniques are well suited for the study of the epidemiology of resistance worldwide, because they use commercially available, formulated amitraz that is easy and inexpensive to obtain.
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- 2007
- Full Text
- View/download PDF
88. First report of permethrin-resistant Boophilus microplus (Acari: Ixodidae) collected within the United States.
- Author
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Miller RJ, Davey RB, and George JE
- Subjects
- Animals, Biological Assay, Cattle, Cattle Diseases parasitology, Cattle Diseases prevention & control, Female, Insecticide Resistance genetics, Ixodidae genetics, Larva, Naphthols metabolism, Polymerase Chain Reaction, Sodium Channels genetics, Tick Infestations prevention & control, Tick Infestations veterinary, United States, Insecticides toxicity, Ixodidae drug effects, Permethrin toxicity
- Abstract
Boophilus microplus (Canestrini) (Acari: Ixodidae), collected in Hidalgo County, TX, were determined to be resistant to permethrin. Discriminating dose (DD) tests at the LC99 and 2X the LC99 of susceptible ticks yielded lower than expected mortalities for permethrin but not for coumaphos or amitraz acaricides. Initial bioassay results confirmed the pyrethroid resistance detected in the DD assays. Two generations of selection with permethrin at a rate > 60% increased the measured resistance ratios from 9.5 (7.9-11.5) to 263 (217-320). Synergist studies suggested that metabolic enzymes were involved in permethrin resistance. Native gel electrophoresis verified that the CZS9 esterase was not involved in resistance to permethrin. Polymerase chain reaction examination revealed the presence of a mutation of the sodium channel gene (Phe [arrow] Ile amino acid substitution in the S6 trans-membrane segment of domain III), in the resistant B&H population. The frequency of this mutation increased after selection with permethrin and concurrent increase in estimated resistance ratios. The B&H population was eradicated from the United States by the U.S. Department of Agriculture's Animal and Plant Health Inspection Service Veterinary Services, Cattle Fever Tick Eradication Program through the use of the organophosphate acaricide coumaphos.
- Published
- 2007
- Full Text
- View/download PDF
89. Compliance analysis of phenylurea and related compounds in drinking water by liquid chromatography/electrospray ionization/mass spectrometry coupled with solid-phase extraction.
- Author
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Li Y, George JE, McCarty CL, and Wendelken SC
- Subjects
- Calibration, Chromatography, Liquid, Phenylurea Compounds chemistry, Phenylurea Compounds analysis, Solid Phase Extraction methods, Spectrometry, Mass, Electrospray Ionization methods, Water Supply analysis
- Abstract
A liquid chromatography/electrospray ionization/mass spectrometry method was reported for the compliance analysis of seven phenylurea compounds and two related herbicides (tebuthiuron and propanil) in drinking water. The volumes of the sample and final extract used in the method were 500 mL and 10 mL, respectively. The obtained method detection limits were less than 0.03 microg/L, and the mean recoveries were 74-128% with a relative standard deviation of 2.6-8.3% for all the studied compounds. The peak-to-peak signal-to-noise ratios ranged from 3.3 for cis-siduron to 34.2 for fluometuron. The accuracy and precision resulting from reagent and drinking water samples fortified at higher concentration levels were similar to these results. Several analytes were detected in the drinking water samples, including tebuthiuron at 0.5 microg/L, propanil at 0.7 microg/L, diuron at 0.1-2.1 microg/L, and linuron at 0.1-0.8 microg/L.
- Published
- 2006
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90. Comparison of the reproductive biology between acaricide-resistant and acaricide-susceptible Rhipicephalus (Boophilus) microplus (Acari: Ixodidae).
- Author
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Davey RB, George JE, and Miller RJ
- Subjects
- Amidines pharmacology, Animals, Female, Male, Organophosphates pharmacology, Pyrethrins pharmacology, Time Factors, Insecticide Resistance, Insecticides pharmacology, Oviposition physiology, Reproduction physiology, Rhipicephalus drug effects, Rhipicephalus physiology
- Abstract
The reproductive fitness of Rhipicephalus (Boophilus) microplus (Canestrini) strains resistant to organophosphate (OP), pyrethroid (P), or formamidine (F) acaricides was compared to an acaricide-susceptible (SUS) strain to determine whether the acquisition of resistance affected reproductive fitness in the resistant strains. The SUS strain females had a 3.0 days preoviposition period, a 12.1 days oviposition period, a 22.5 days egg incubation period, a mean of 3670 eggs per female, and a mean percentage egg hatch of 78.1%, which were all remarkably similar to these same parameters reported for this species throughout the world. The reproductive biology of the P-resistant strain (PYR) and the F-resistant strain (FOR) were, for the most part, similar to those of the SUS strain. In the few instances where statistical differences did occur there was little evidence that the variation had any biological basis that could be attributed to a reduction in fitness related to resistance to P or F acaricides. Although the comparison of reproductive parameters of the OP-resistant strain (OPR) and the SUS strain identified statistical differences between the mean egg incubation and oviposition periods, the magnitude of the differences was not sufficient to conclude that the OPR strain was biologically less fit than the SUS strain. However, the OPR strain produced 30% fewer eggs (2562 eggs per female) than the SUS strain (3670 eggs per female) indicating the acquisition of resistance placed the OPR at a selective disadvantage relative to the SUS strain. This coupled with a lower, though non-significant, egg hatch was used to predict there would be a reduction of at least 34.1% in larval numbers available to potentially re-infest subsequent cattle than were available from the SUS strain. These data may aid the development of management strategies that can be used to control OP-resistant ticks.
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- 2006
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91. Sequencing a new target genome: the Boophilus microplus (Acari: Ixodidae) genome project.
- Author
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Guerrero FD, Nene VM, George JE, Barker SC, and Willadsen P
- Subjects
- Animals, Genomics, Humans, Research Design, Sequence Analysis, DNA methods, Arachnid Vectors genetics, Genome, Insect genetics, Ixodidae genetics, Sequence Analysis, DNA veterinary
- Abstract
The southern cattle tick, Boophilus microplus (Canestrini), causes annual economic losses in the hundreds of millions of dollars to cattle producers throughout the world, and ranks as the most economically important tick from a global perspective. Control failures attributable to the development of pesticide resistance have become commonplace, and novel control technologies are needed. The availability of the genome sequence will facilitate the development of these new technologies, and we are proposing sequencing to a 4-6X draft coverage. Many existing biological resources are available to facilitate a genome sequencing project, including several inbred laboratory tick strains, a database of approximately 45,000 expressed sequence tags compiled into a B. microplus Gene Index, a bacterial artificial chromosome (BAC) library, an established B. microplus cell line, and genomic DNA suitable for library synthesis. Collaborative projects are underway to map BACs and cDNAs to specific chromosomes and to sequence selected BAC clones. When completed, the genome sequences from the cow, B. microplus, and the B. microplus-borne pathogens Babesia bovis and Anaplasma marginale will enhance studies of host-vector-pathogen systems. Genes involved in the regeneration of amputated tick limbs and transitions through developmental stages are largely unknown. Studies of these and other interesting biological questions will be advanced by tick genome sequence data. Comparative genomics offers the prospect of new insight into many, perhaps all, aspects of the biology of ticks and the pathogens they transmit to farm animals and people. The B. microplus genome sequence will fill a major gap in comparative genomics: a sequence from the Metastriata lineage of ticks. The purpose of the article is to synergize interest in and provide rationales for sequencing the genome of B. microplus and for publicizing currently available genomic resources for this tick.
- Published
- 2006
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92. Roles played by esterase activity and by a sodium channel mutation involved in pyrethroid resistance in populations of Boophilus microplus (Acari: Ixodidae) collected from Yucatan, Mexico.
- Author
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Rosario-Cruz R, Guerrero FD, Miller RJ, Rodriguez-Vivas RI, Domínguez-García DI, Cornel AJ, Hernandez-Ortiz R, and George JE
- Subjects
- Animals, Biological Assay, Cattle, Female, Gene Frequency genetics, Genotype, Insect Vectors enzymology, Ixodidae enzymology, Larva physiology, Mexico, Mutation genetics, Sodium Channels physiology, Statistics as Topic, Survival, Esterases metabolism, Insect Vectors genetics, Insecticide Resistance genetics, Ixodidae genetics, Pyrethrins, Sodium Channels genetics
- Abstract
Pyrethroid resistance in Boophilus microplus (Canestrini) (Acari: Ixodidae) was studied by correlating discriminating-dose (DD) bioassay results and esterase activity or the frequency of a sodium channel mutation known to be involved in pyrethroid resistance in nine field strains of B. microplus from Yucatan, Mexico. Two tick strains (P67 and B74) were identified as susceptible to cypermethrin, deltamethrin, and flumethrin by DD, one strain (P65) was susceptible to cypermethrin and resistant to deltamethrin and flumethrin, and six strains were resistant to cypermethrin, delta-methrin, and flumethrin (T11, M10, C54, R49, B71, and T66). By using polymerase chain reaction, only 6.0 and 6.2% of resistance allele (R) was found in the susceptible strains (P67 and B74, respectively). In the T66 strain, with 100% of larval survival to the DD of pyrethroids as measured by the larval packet test (LPT), 98.0% of the gene pool contained the R allele. Positive correlations between the larval survival and the percentage of the R allele were found (deltamethrin r2 = 0.8875, P < 0.01; cypermethrin r2 = 0.8563, P < 0.01; and flumethrin r2 = 0.8491, P < 0.01). There were no significant correlations between the level of larval survival and esterase-based hydrolytic activity. It was concluded that within the B. microplus populations studied, resistance to flumethrin, deltamethrin, or cypermethrin was because of the novel sodium channel mutation (Phe-->Ile amino acid substitution in the S6 transmembrane segment of domain III), and there was a correlation between tick mortality by pyrethroid exposure (larval survival) and the presence of R allele. It was not determined whether enhanced esterase-based hydrolytic activity was involved in pyrethroid resistance in the populations tested.
- Published
- 2005
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93. First report of organophosphate-resistant Boophilus microplus (Acari: Ixodidae) within the United States.
- Author
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Miller RJ, Davey RB, and George JE
- Subjects
- Animals, Dose-Response Relationship, Drug, Lethal Dose 50, Regression Analysis, Survival Analysis, Texas, Cattle parasitology, Coumaphos toxicity, Diazinon toxicity, Insecticide Resistance, Insecticides toxicity, Ixodidae drug effects
- Abstract
Boophilus microplus (Canestrini), collected from Starr County, Texas, were determined to be resistant to the organophosphorus acaricides coumaphos and diazinon. Initial bioassay results from wild-collected ticks produced a probit regression slope (SE) of 3.96 (0.22), which was different from that obtained from a susceptible reference population 6.97 (0.38). Resistance ratios (RRs) (95% CI) indicated that the population was resistant to coumaphos 3.6 (3.4-3.8), 5.0 (4.5-5.5), and 6.5 (5.4-7.7) at the LC50,90,99, respectively. A second collection of wild ticks made 12 d after all cattle in the infested pasture were treated with coumaphos produced a slope (SE) that was not significantly different from a susceptible laboratory reference population. A second bioassay found these ticks to be resistant to diazinon,RR (95%CI) = 7.1 (6.5-7.7),11.7 (10.3-13.3),17.7 (14.5-21.5) at the LC50,90,99, respectively. The slope (SE) generated from the diazinon bioassay with the resistant ticks was different than that of a reference strain, 2.98 (0.12) and 6.09 (0.35), respectively. The high-dose strategy used by the Cattle Fever Tick Eradication Program was able to eradicate coumpahos-resistant B. microplus after just two treatments of coumaphos, 12 d apart.
- Published
- 2005
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94. Pc 4 photodynamic therapy of U87-derived human glioma in the nude rat.
- Author
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George JE 3rd, Ahmad Y, Varghai D, Li X, Berlin J, Jackowe D, Jungermann M, Wolfe MS, Lilge L, Totonchi A, Morris RL, Peterson A, Lust WD, Kenney ME, Hoppel CL, Sun J, Oleinick NL, and Dean D
- Subjects
- Animals, Brain Neoplasms metabolism, Brain Neoplasms pathology, Cell Line, Tumor, Glioma metabolism, Glioma pathology, Humans, Indoles administration & dosage, Indoles pharmacokinetics, Injections, Intravenous, Photosensitizing Agents administration & dosage, Photosensitizing Agents pharmacokinetics, Rats, Rats, Nude, Brain Neoplasms drug therapy, Glioma drug therapy, Indoles therapeutic use, Photochemotherapy, Photosensitizing Agents therapeutic use
- Abstract
Background and Objectives: As a potential therapy for malignant glioma, we tested the phthalocyanine photosensitizer Pc 4 for: (1) rapid clearance from the vasculature, (2) specificity for glioma, and (3) tumoricidal photosensitizing capability., Study Design/materials and Methods: Parenchymal injection of U87 cells into athymic rat brains (N = 100) was followed after 12 days by tail vein injection of 0.5 mg/kg Pc 4. After 1 day, the tumor was illuminated with either 5 (N = 11) or 30 (N = 16) J/cm(2) red light at 672 nm. Sacrifice was 1 day later. The brains from these 27 animals underwent H&E (necrosis) and TUNEL assay (apoptosis) histology. Pc 4 concentration of explanted brains and tumors (N = 16), and all blood samples (N = 52) were determined by HPLC-MS 1 day post Pc 4 administration., Results: Tumor-specific apoptosis was almost uniformly seen; however, necrosis was found mostly in the high-light-dose group. Pc 4 concentration in bulk tumor averaged 3.8 times greater than in normal brain., Conclusions: These results warrant expanding this pre-clinical study to seek effective baseline Pc 4 drug- and light-doses and infusion-to-photoirradiation timing that would be necessary for a Pc 4-mediated PDT clinical trial for glioma patients., (Copyright 2005 Wiley-Liss, Inc.)
- Published
- 2005
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95. Carbaryl resistance in Mexican strains of the southern cattle tick (Acari: Ixodidae).
- Author
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Li AY, Davey LR, and George JE
- Subjects
- Acetylcholinesterase, Animals, Cattle, Mexico, Carbaryl, Insecticide Resistance, Insecticides, Ixodidae
- Abstract
Susceptibility to carbaryl in six Mexican strains of the southern cattle tick, Boophilus microplus (Canestrini), was evaluated with the Food and Agricultural Organization larval packet test. Tick strains from the cattle fever tick quarantine zone in Texas were more susceptible to carbaryl than to coumaphos or diazinon. Compared with the susceptible reference (Gonzalez) strain, Mexican tick strains demonstrated 10.9-59.5-fold resistance to carbaryl. Significant cross-resistance was found between carbaryl and the organophosphate acaricides coumaphos and diazinon. Bioassay results with synergists suggested that metabolic detoxification mechanisms did not play a major role in carbaryl resistance. Resistance to carbaryl was likely conferred by insensitive acetylcholinesterase. The implications of carbaryl resistance in tick eradication and control also are discussed.
- Published
- 2005
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96. Therapeutic and persistent efficacy of a single injection treatment of ivermectin and moxidectin against Boophilus microplus (Acari: Ixodidae) on infested cattle.
- Author
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Davey RB, Miller JA, George JE, and Miller RJ
- Subjects
- Animals, Cattle, Cattle Diseases parasitology, Female, Ixodidae growth & development, Life Cycle Stages drug effects, Tick Infestations drug therapy, Cattle Diseases drug therapy, Insecticides therapeutic use, Ivermectin therapeutic use, Ixodidae drug effects, Macrolides therapeutic use, Tick Infestations veterinary
- Abstract
The effectiveness of a single treatment with either ivermectin or moxidectin was determined by administering a single subcutaneous injection of each endectocide at 200 microg per kg body weight to cattle infested with all parasitic developmental stages (adults, nymphs, and larvae) of Boophilus microplus (Canestrini). The percentage reduction in the number of females that reached repletion following treatment (outright kill) was 94.8 and 91.1% for ivermectin and moxidectin, respectively. In addition, the reproductive capacity of the females that did survive to repletion was reduced by > 99%, regardless of the endectocide. Based on these two factors, the therapeutic level of control obtained against ticks on the cattle at the time of treatment was 99.0 and 99.1% for ivermectin and moxidectin, respectively. Engorged females recovered from either group of treated cattle weighed approximately 3-times less than untreated females, and the egg masses produced by treated females weighed approximately 5-8-times less than egg masses produced by untreated females. Partitioning of data into three separate 7-d post-treatment intervals allowed for an estimation of the efficacy of each endectocide against each individual parasitic development stage (adult, nymph, and larva). Results indicated that both endectocides were > or =99.7% effective against ticks that were in either the adult or nymphal stage at the time of treatment. However, the level of control against ticks in the larval stage of development at treatment was significantly lower at 97.9 and 98.4% for ivermectin and moxidectin, respectively. Analysis of the persistent (residual) activity of the two endectocides indicated that neither material provided total protection against larval re-infestation for even 1-wk following treatment. Against larvae infested 1-4 wk following treatment, the level of control with moxidectin ranged from 92.4% (1 wk) to 19.5% (4 wk). These control levels were higher at each weekly interval than for ivermectin, which ranged from 82.4% (1 wk) to 0.0% (4 wk). The potential for the use of these injectable endectocide formulations in the US Boophilus Eradication Program is discussed.
- Published
- 2005
- Full Text
- View/download PDF
97. Mode of inheritance of amitraz resistance in a Brazilian strain of the southern cattle tick, Boophilus microplus (Acari: Ixodidae).
- Author
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Li AY, Davey RB, Miller RJ, and George JE
- Subjects
- Animals, Biological Assay veterinary, Brazil, Cattle, Crosses, Genetic, Female, Insecticides, Ixodidae drug effects, Lethal Dose 50, Male, Mortality, Tick Infestations parasitology, Cattle Diseases parasitology, Insecticide Resistance genetics, Ixodidae genetics, Tick Infestations veterinary, Toluidines toxicity
- Abstract
The southern cattle tick, Boophilus microplus (Canestrini), has developed resistance to amitraz in several countries in recent years. A study was conducted at the USDA Cattle Fever Tick Research Laboratory in Texas to investigate the mode of inheritance of amitraz resistance with cross-mating experiments. The Muñoz strain, a laboratory reared acaricide-susceptible reference strain, was used as the susceptible parent and the Santa Luiza strain, originating in Brazil, was used as the resistant parent. A modified Food and Agriculture Organization Larval Packet Test was used to measure the levels of susceptibility of larvae of the parental strains, F1, backcross, F2, and F3 generations. Results of reciprocal crossing experiments suggested that amitraz resistance was inherited as an incomplete recessive trait. There was a strong maternal effect on larval progeny's susceptibility to amitraz in both the F1 and the subsequent generations. The values of the degree of dominance were estimated at -0.156 and -0.500 for the F1 larvae with resistant and susceptible female parents, respectively. Results of bioassays on larval progeny of the F1 backcrossed with the resistant parent strain and that of the F2 generations suggested that more than one gene was responsible for amitraz resistance in the Santa Luiza strain. Comparisons of biological parameters (engorged female weight, egg mass weight, and female-to-egg weight conversion efficiency index) indicated significant differences between different genotypes. The differences appeared to be heritable, but not related to amitraz resistance. Results from this study may have significant implications for the management of amitraz resistance.
- Published
- 2005
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- View/download PDF
98. Control of an organophosphate-resistant strain of Boophilus microplus (Acari: Ixodidae) infested on cattle after a series of dips in coumaphos applied at different treatment intervals.
- Author
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Davey RB, George JE, and Miller RJ
- Subjects
- Animals, Cattle, Cattle Diseases drug therapy, Coumaphos administration & dosage, Insecticides therapeutic use, Tick Infestations drug therapy, Cattle Diseases parasitology, Coumaphos therapeutic use, Insecticide Resistance, Ixodidae, Tick Infestations veterinary
- Abstract
Efficacy of multiple dip treatments (one to three) at 0.3% active ingredient (AI) coumpahos applied at 7- or 10-d intervals was determined against organophosphate (OP)-resistant Boophilus microplus (Canestrini). None of the treatments totally prevented repletion of all females. In the 7 d after one treatment, the percentage of reduction of female ticks was 24.8%, whereas in the 10 d after one treatment, the reduction of female numbers was 47.1%. Application of two or three dips at either interval provided substantially higher reductions in female numbers than either single treatment (range 80.2-88.8%). Percentage reduction of the index of fecundity of females (designated as percentage of control) in the 7 d after one dip provided 46.8% control, whereas control in the 10 d after one treatment was 65.6%. Again, application of two or three dips at either interval provided substantially higher control (range 92.9 to >99.9%). Although control levels after two or three dips were similar, only application of three dips at either interval provided a high enough level of control (>99.5%) to ensure that the U.S. Boophilus eradication program would not be at risk of inadvertently dispersing viable ticks. Thus, although no treatment regime prevented repletion of all treated females, application of three dips at either interval virtually eliminated production of reproductively active females, thereby eliminating the possibility that ticks would become established. It should be noted that ticks possessing different OP resistance mechanisms than ticks in this study could have higher reproductive capabilities than were observed against these treatment regimes.
- Published
- 2004
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99. Therapeutic and persistent efficacy of a single application of doramectin applied either as a pour-on or injection to cattle infested with Boophilus microplus (Acari: Ixodidae).
- Author
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George JE and Davey RB
- Subjects
- Animals, Cattle, Cattle Diseases prevention & control, Female, Insecticides administration & dosage, Ivermectin administration & dosage, Male, Ovum physiology, Reproducibility of Results, Reproduction drug effects, Tick Infestations prevention & control, Cattle Diseases parasitology, Insecticides therapeutic use, Ivermectin analogs & derivatives, Ivermectin therapeutic use, Ixodidae, Tick Infestations veterinary
- Abstract
The efficacy of a single treatment with a pour-on application or a subcutaneous injection of the macrocyclic lactone endectocide, doramectin, was evaluated in separate trials on Hereford heifers infested with Boophilus microplus (Canestrini). Significantly fewer ticks per calf were recovered from both groups of treated animals than from the complimentary untreated calves. The mean weights of engorged females and egg masses from both pour-on-treated and injectable-treated calves were also significantly smaller than the complimentary variables for the two groups of untreated calves. Among the treated groups, the mean weight of females from calves treated with the subcutaneous injection was 55% less than females from cattle that received the pour-on treatment and the weights of egg masses were 71% lighter than those from the pour-on-treated group. The estimates of percentage control for the two treatments were 88.6 for the pour-on formulation and a notably higher 99.8 for the injectable formulation. To obtain estimates of the effect of the treatments on the parasitic stages of the tick, cattle were infested with B. microplus larvae at three weekly intervals beginning 18 d pretreatment to ensure that, on the day of treatment, ticks in all three parasitic stages (adult, nymph, larva) would be on the cattle. The effect of the treatments on each parasitic stage was estimated by partitioning detached females into three groups by noting in which of the three 7-d intervals after detachment of engorged females began that detachment occurred. There was no difference for either the pour-on or injectable in the effect of the specific treatment on each parasitic stage. The persistent efficacy of the pour-on treatment against larvae placed on the hosts 1 wk after treatment was zero. The persistent efficacy of the injectable treatment ranged from 100 to 82.1% (mean, 93.7%) against the larvae placed on calves the first 3 wk after treatment and was still 44% against the fourth weekly posttreatment infestation. The injectable doramectin is a potential alternative to the coumaphos product now used as a precautionary treatment at USDA, Veterinary Services, Livestock Import Stations, for cattle exported from Mexico.
- Published
- 2004
- Full Text
- View/download PDF
100. Detection and characterization of amitraz resistance in the southern cattle tick, Boophilus microplus (Acari: Ixodidae).
- Author
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Li AY, Davey RB, Miller RJ, and George JE
- Subjects
- Animals, Animals, Wild parasitology, Cattle parasitology, Dogs parasitology, Geography, Larva drug effects, Species Specificity, United States, United States Department of Agriculture, Insect Repellents toxicity, Insecticide Resistance drug effects, Ticks physiology, Toluidines toxicity
- Abstract
Amitraz, a formamidine acaricide, plays an important role in the control of the southern cattle tick, Boophilus microplus (Canestrini), and other tick species that infest cattle, dogs, and wild animals. Although resistance to amitraz in B. microplus was previously reported in several countries, the actual measurement of the level of amitraz resistance in ticks has been difficult to determine due to the lack of a proper bioassay technique. We conducted a survey, by using a newly reported technique that was a modification of the standard Food and Agriculture Organization larval packet test, to measure the levels of resistance to amitraz in 15 strains of B. microplus from four major cattle-producing states in Mexico. Low-order resistance (1.68- to 4.58-fold) was detected in 11 of those strains. Our laboratory selection using amitraz on larvae of the Santa Luiza strain, which originated from Brazil, achieved a resistance ratio of 153.93 at F6, indicating the potential for high resistance to this acaricide in B. microplus. Both triphenylphosphate and piperonyl butoxide significantly synergized amitraz toxicity in both resistant and susceptible tick strains. Diethyl maleate synergized amitraz toxicity in one resistant strain but had no effect on the susceptible strain and had minor antagonistic effects on two other resistant strains. Target site insensitivity, instead of metabolic detoxification mechanisms, might be responsible for amitraz resistance observed in the Santa Luiza strain and possibly in other amitraz resistant B. microplus ticks from Mexico. The Santa Luiza strain also demonstrated high resistance to pyrethroids and moderate resistance to organophosphates. Multiple resistance shown in this strain and other B. microplus strains from Mexico poses a significant challenge to the management of B. microplus resistance to acaricides in Mexico.
- Published
- 2004
- Full Text
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