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This research aimed to evaluate an intervention to increase sexual health awareness and encourage testing for STIs within a community setting (a sauna), in an attempt to reduce sexual risk behaviours within MSM (men who have sex with men). Men were provided with sexual health information and offered sexual health testing monthly in the sauna. Questionnaires were administered over three time points to measure sexual risk behaviours and use of sexual health services. 539 questionnaires were completed; there was a high reported incidence of sexual risk behaviours, and low use of sexual health services, although the men were receptive to testing services within community settings. Health promotion appears to have impacted upon anal sex, with a consistent decrease in unprotected intercourse compared to very little change observed nationally during this period. Reported intentions to use community testing services are promising, suggesting this may be an effective way of encouraging high-risk groups to engage with their sexual health. [ABSTRACT FROM AUTHOR]

Eight first-time and eight second-time working class mothers were observed interacting with their newborn babies during the first half-hour of life. In all cases the father was present for at least some of this period. The interactions were notable for their passivity, mothers looked for long periods at their babies and engaged in some finger-tip touching of the babies face and head, but they engaged in very little exploration of the babies, few vocalizations and few expressive acts such as kissing. However, the presence of the father was associated with more intense mother-newborn interaction. First-time but not second-time fathers tended to be excluded from interaction with either the mother or the baby at this time. These results are discussed in the light of current thinking on mother-newborn bonding and the role of midwifery staff in promoting that bonding process. [ABSTRACT FROM AUTHOR]

A questionnaire based upon DiClemente's AIDS Information Survey was used to assess knowledge, attitudes and beliefs about AIDS and estimates of personal risk. It was completed by 238 students at the University of Zimbabwe in Spring 1988. The results showed encouragingly high levels of knowledge concerning AIDS, but these were not consistent across subscales. Generally, knowledge of transmission and characteristics was high, but knowledge of causes and prevention was more variable. Analysis of personal risk showed that AIDS was perceived as a serious threat and the majority of respondents expressed concern about contracting AIDS. A significant correlation was found between knowledge and personal risk though this only accounts for 9% of the variance, indicating that knowledge by itself has limited impact upon risk estimates. Comparisons of gender, marital status differences, and differences in the amount of education received about AIDS, yielded few significant differences in total knowledge scores, although there was encouraging evidence of greater pick up of specific messages, e.g., the use of condoms as a means of reducing risk, amongst those receiving more education. The results are compared with findings from USA and Western Europe and suggestions are made for the focus of future health education programmes in Zimbabwe. [ABSTRACT FROM AUTHOR]

Objectives This report documents the results of a validation study conducted to assess the reliability of two algorithms applied to the 2016 National Hospital Care Survey. One algorithm identifies opioid-involved and opioid overdose hospital encounters, and the other identifies encounters with patients that have substance use disorders and selected mental health issues. These algorithms use both medical codes and natural language processing to identify encounters. Methods To validate the algorithms, medical record abstraction was performed on a stratified sample of 900 hospital encounters from the 2016 National Hospital Care Survey. The abstractors recorded their determinations of opioid involvement, opioid overdose, substance use disorder, and mental health issues on a standard form. Abstractors' determinations were compared with algorithm output to assess the overall performance using F-score and Matthews correlation coefficient. The latter provided a secondary measure of performance. The 2016 National Hospital Care Survey data are unweighted and not nationally representative. Results Overall algorithm performance varied by topic and by metric. The opioid-involvement algorithm achieved the highest performance, performing well with an F-score of 0.95, followed by the substance use disorder algorithm (F-score of 0.79), the mental health issues algorithm (F-score of 0.68), and the opioid overdose algorithm (F-score of 0.48). Assessment by Matthews correlation coefficient indicated an overall poorer level of performance, ranging from a high of 0.57 for the mental health issues algorithm to a low of 0.33 for the opioid-involvement algorithm. The causes of false positives and false negatives likewise varied, including both overly broad code and keyword inclusions as well as incompleteness of data submitted to the National Hospital Care Survey. Conclusion The validation study illustrates which aspects of the developed algorithms performed well and which aspects should be altered or discarded in future iterations. It further emphasizes the importance of data completeness, therefore laying the groundwork for improvements to future survey analyses., (All material appearing in this report is in the public domain and may be reproduced or copied without permission; citation as to source, however, is appreciated.)

Objective-This report provides a descriptive analysis of a sample of adult patients who visited the emergency department (ED) for nonfatal opioid overdose (NOO), using restricted-use 2016 National Hospital Care Survey data linked to the 2016-2017 National Death Index and the 2016-2017 Drug-Involved Mortality data from the National Center for Health Statistics., (All material appearing in this report is in the public domain and may be reproduced or copied without permission; citation as to source, however, is appreciated.)

Background and Objectives: The onset of the COVID-19 pandemic severely threatened all aspects of academic family medicine, constituting a crisis. Multiple publications have identified recommendations and documented the creative responses of primary care and academic organizations to address these challenges, but there is little research on how decisions came about. Our objective was to gain insight into the context, process, and nature of family medicine leaders' discussions in pivoting to address a crisis., Methods: We used a qualitative descriptive design to explore new dimensions of existing concepts. The setting was the academic family medicine department at the University of Toronto. To identify leadership themes, we used the constant comparative method to analyze transcripts of monthly meetings of the departmental executive: three meetings immediately before and three following the declaration of a state emergency in Ontario., Results: Six themes were evident before and after the onset of the pandemic: building capacity in academic family medicine; developing leadership; advancing equity, diversity, and inclusion; learner safety and wellness; striving for excellence; and promoting a supportive and collegial environment. Five themes emerged as specific responses to the crisis: situational awareness; increased multidirectional communication; emotional awareness; innovation in education and patient care; and proactive planning for extended adaptation to the pandemic., Conclusion: Existing cultural and organizational approaches formed the foundation for the crisis response, while crisis-specific themes reflected skills and attitudes that are essential in clinical family medicine, including adapting to community needs, communication, and emotional awareness.

This report documents the development of the 2016 National Hospital Care Survey (NHCS) Co-occurring Disorders Algorithm, which can be used to identify patients with an opioid-involved hospital encounter who had lifetime diagnoses of both a substance use disorder and a selected mental health issue. Lifetime diagnoses are defined as diagnoses at any point in the past or during the current encounter. This algorithm was created to complement the earlier NHCS Enhanced Opioid Identification Algorithm designed to improve the classification of patients with opioid-involved hospital encounters., (All material appearing in this report is in the public domain and may be reproduced or copied without permission; citation as to source, however, is appreciated.)

This report demonstrates the use of National Hospital Care Survey (NHCS) data to describe characteristics of patients experiencing opioid-involved hospital encounters with co-occurring disorders, defined as lifetime diagnoses of both a substance use disorder (SUD) and a selected mental health issue (MHI), that is, diagnosed at any point in the past or during the present encounter., (All material appearing in this report is in the public domain and may be reproduced or copied without permission; citation as to source, however, is appreciated.)

Approaches to modeling episodic recognition memory often imply a separability from semantic memory insofar as an implicit tabula rasa (i.e., blank slate) assumption is apparent in many simulations. This is evident in the common practice of having new test probes correspond to zero memory traces in the store while old test probes correspond to traces representing instances of items' occurrence on a study list. However, in list-learning studies involving word lists, none of the test items would actually correspond to zero items in the person's memory, as all of the test words are generally known to participants, whether old or new. By focusing on a list-learning recognition phenomenon that likely results from feature-based familiarity detection and necessarily involves a role of preexisting knowledge in its mechanisms-the semantic-feature-based recognition without cued recall phenomenon-we show how incorporating preexisting knowledge into the MINERVA 2 model enables it to simulate previously shown empirical patterns with this phenomenon. The simulation patterns reported here raise new theoretical implications worth further exploration, such as the extent to which the variances change in the signal versus the noise distribution when preexisting knowledge is present versus absent in the simulations., (© 2021. The Psychonomic Society, Inc.)

Objectives This report documents the development of the 2016 National Hospital Care Survey (NHCS) Enhanced Opioid Identification Algorithm, an algorithm that can be used to identify opioid-involved and opioid overdose hospital encounters. Additionally, the algorithm can be used to identify opioids and opioid antagonists that can be used to reverse opioid overdose (naloxone) and to treat opioid use disorder (naltrexone)., (All material appearing in this report is in the public domain and may be reproduced or copied without permission; citation as to source, however, is appreciated.)

Salmonella remains the leading cause of foodborne illness in the United States, and the dissemination of drug-resistant Salmonellae through the food chain has important implications for treatment failure of salmonellosis. We investigated the ecology of Salmonella in integrated broiler production in order to understand the flow of antibiotic susceptible and resistant strains within this system. Data were analyzed from a retrospective study focused on antimicrobial resistant Salmonella recovered from commercial broiler chicken farms conducted during the initial years of the US FDA's foray into retail meat surveillance by the National Antimicrobial Resistance Monitoring System (NARMS). Sixty-three percentage of Salmonella were pan-susceptible to a panel of 19 antimicrobials used by the NARMS program. Twenty-five antimicrobial resistance phenotypes were observed in Salmonella isolated from two broiler chicken farms. However, Salmonella displaying resistance to streptomycin, alone, and in combination with other antibiotics was the most prevalent (36.3%) antimicrobial resistance phenotype observed. Resistance to streptomycin and sulfadimethoxine appeared to be linked to the transposon, Tn 21 . Combinations of resistance against streptomycin, gentamicin, sulfadimethoxine, trimethoprim, and tetracycline were observed for a variety of Salmonella enterica serovars and genetic types as defined by pulsed-field gel electrophoresis. There were within and between farm differences in the antibiotic susceptibilities of Salmonella and some of these differences were linked to specific serovars. However, farm differences were not linked to antibiotic usage. Analysis of the temporal and spatial distribution of the endemic Salmonella serovars on these farms suggests that preventing vertical transmission of antibiotic-resistant Salmonella would reduce carcass contamination with antibiotic-resistant Salmonella and subsequently human risk exposure.

Objective: Diabetes guidelines recommend individualized glycemic targets: tighter control in younger, healthier patients and consideration of more moderate control in the elderly and those with coexisting illnesses. Our objective was to examine whether glycemic control varied by age and comorbidities in Canadian primary care., Research Design and Methods: Cross-sectional study using data from the electronic medical records of 537 primary care providers across Canada; 30 416 patients with diabetes, aged 40 or above, with at least one encounter and one hemoglobin A1c (HbA1c) measurement between 1 January 2012 and 31 December 2013. The outcome was the most recent HbA1c, categorized into three levels of control: tight (<7.0% or <53 mmol/mol), moderate (7.0%-8.5%, 53 mmol/mol-69.5 mmol/mol) and uncontrolled (>8.5% or >69.5 mmol/mol). We adjusted for several factors associated with glycemic control including treatment intensity., Results: Younger patients (aged 40-49) were more likely to have moderate as opposed to tight control than the older patients (aged 80+) (OR 1.28; 95% CI 1.11 to 1.49, p=0.001). The youngest were also more likely to have uncontrolled as opposed to moderately controlled glycemia (OR 3.39; 95% CI 2.75 to 4.17, p<0.0001). Patients with no or only one comorbidity were more likely to have moderate as opposed to tight control than those with three or more comorbidities (OR 1.66;95% CI 1.46 to 1.90, p<0.0001)., Conclusions: Levels of glycemic control, given age and comorbidities appear to differ from guideline recommendations. Research is needed to understand these discrepancies and develop methods to assist providers in personalizing glycemic targets., Competing Interests: Competing interests: MG holds an investigator award from the Department of Family and Community Medicine, University of Toronto.

Introduction: All adolescent and adult patients should be asked if they smoke. Data entered in electronic medical records offer new opportunities to study tobacco-related clinical activities. The purpose of this study is to examine the recording of tobacco use in Canadian electronic medical records., Methods: Data were collected on September 30, 2013, and analyzed in 2014. Data on 249,223 patients that were aged ≥16 years as of September 30, 2013 and had at least one primary care encounter in the previous 2 years were included. The proportion of patients with information on tobacco use entered in a summative health profile was calculated. Associations between data gaps and patient or physician factors were examined., Results: Information on tobacco use was available for 64.4% of patients. Physicians using an electronic medical record for ≥4 years were more likely to have data (AOR=4.57, 95% CI=1.84, 7.29, p<0.0001). Patients aged ≥30 years were more likely to have tobacco information present (AOR=2.92, 95% CI=2.82, 3.02, p<0.0001, for patients aged 30-59 compared to those aged <30 years), as were patients with any comorbidities (AOR=1.41, 95% CI=1.36, 1.45, p<0.0001, for patients with one or two comorbidities compared with none) or more visits., Conclusions: A third of Canadians in this sample lacked data on tobacco in their electronic medical record. Younger, healthier people were less likely to have information about their smoking status. Efforts to improve the recording of tobacco-related information in electronic medical records, especially for younger patients, are needed., (Copyright © 2015 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.)

Aims: To evaluate susceptibility of Pseudomonas aeruginosa veterinary isolates to antibiotics and disinfectants., Methods and Results: Pseudomonas aeruginosa isolates collected from dogs (n = 155) and other animals (n = 20) from sixteen states during 1994-2003 were tested for susceptibility. Most isolates were resistant to twenty-one antimicrobials tested, and the highest prevalence of resistance was to β-lactams (93.8%) and sulphonamides (93.5%). Fluoroquinolone resistance did not increase from 1994 to 2003. Ciprofloxacin and enrofloxacin had a 5 and 16% prevalence of resistance, respectively, while sarafloxacin and nalidixic acid had a prevalence of resistance of 97 and 98%, respectively. Strains were pan-resistant to triclosan and chlorhexidine, were highly resistant to benzalkonium chloride and demonstrated high susceptibility to other disinfectants. Didecyldimethylammonium chloride was the most active ammonium chloride. Inducible resistance was observed to cetyl ammonium halides, chlorhexidine and benzyl ammonium chlorides, which formulate disinfectants used in veterinary clinics and dairies. Organic acid inhibition was associated with the dissociated acid species., Conclusions: Dissociated organic acids appear able to inhibit Ps. aeruginosa, and rates of fluoroquinolone resistance merit sustained companion animal isolate surveillance., Significance and Impact of the Study: This is the first report of Ps. aeruginosa susceptibility to 24 disinfectants and illustrates the high resistance of Ps. aeruginosa to both antibiotics and disinfectants., (Published 2014. This article is a U.S. Government work and is in the public domain in the USA.)

There is conflicting data regarding whether commercial chilling has any effect on persistence of Salmonella serovars, including antibiotic resistant variants, on chicken carcasses. A total of 309 Salmonella Typhimurium and Salmonella Kentucky isolates recovered from pre- and post-chill whole broiler carcasses were characterized for genetic relatedness using Pulsed Field Gel Electrophoresis (PFGE) and for the presence of virulence factors (invA, pagC, spvC) by PCR and for aerobactin and colicin production by bioassays. A subset of these isolates (n = 218) displaying resistance to either sulfisoxazole and/or ceftiofur [S. Typhimurium (n = 66) and S. Kentucky (n = 152)] were further tested for the presence of associated antibiotic resistance elements (class-I integrons and blaCMY genes) by PCR. All 145 ceftiofur resistant S. Kentucky and S. Typhimurium isolates possessed blaCMY genes. Class-I integrons were only detected in 6.1% (n = 4/66) of sulfisoxazole resistant S. Typhimurium isolates. The PFGE analysis revealed the presence of genetically diverse populations within the recovered isolates but clusters were generally concordant with serotypes and antimicrobial resistance profiles. At a 100% pattern similarity index, thirty-six percent of the undistinguishable S. Typhimurium and 22% of the undistinguishable S. Kentucky isolates were recovered from the same chilling step. All isolates possessed the invA and pagC genes, but only 1.4%possessed spvC. Irrespective of the chilling step, there was a significant difference (P < 0.05) in the production of aerobactin and colicin between S. Typhimurium and S. Kentucky isolates. Taken together, these results indicate that chilling impacted the recovery of particular Salmonella clonal groups but had no effect on the presence of class-I integrons, blaCMY genes, and tested virulence factors., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

The primary purpose of this study was to determine if methicillin-resistant Staphylococcus aureus (MRSA) strains could be identified in the milk of dairy cattle in a Paso del Norte region dairy of the United States. Using physiological and PCR-based identification schemes, a total of 40 Staph. aureus strains were isolated from 29 raw milk samples of 133 total samples analyzed. Pulsed-field gel electrophoresis after digestion with the SmaI enzyme revealed that the 40 confirmed strains were represented by 5 pulsed-field types, which each contained 3 or more strains. Of 7 hospital strains isolated from cows undergoing antibiotic therapy, 3 demonstrated resistance to 3 or more antimicrobial classes and displayed similar pulsed-field gel electrophoresis patterns. A secondary purpose of this study was to elucidate the evolutionary relationships of strains isolated in this study to genomically characterized Staph. aureus strains. Therefore, Roche 454 GS (Roche Diagnostics Corp., Dallas, TX) pyrosequencing was used to produce draft genome sequences of an MRSA raw milk isolate (H29) and a methicillin-susceptible Staph. aureus (PB32). Analysis using the BLASTn database (http://blast.ncbi.nlm.nih.gov/) demonstrated that the H29 draft genome was highly homologous to the human MRSA strain JH1, yet the β-lactamase plasmid carried by H29 was different from that carried by JH1. Genomic analysis of H29 also clearly explained the multidrug resistance phenotype of this raw milk isolate. Analysis of the PB32 draft genome (using BLASTn) demonstrated that this raw milk isolate was most related to human MRSA strain 04-02981. Although PB32 is not a MRSA, the PB32 draft genome did reveal the presence of a unique staphylococcal cassette mec (SCCmec) remnant. In addition, the PB32 draft genome revealed the presence of a novel bovine staphylococcal pathogenicity island, SaPIbovPB32. This study demonstrates the presence of clones closely related to human and (or) bovine Staph. aureus strains circulating in a dairy herd., (Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

Despite extensive surveillance, food-borne Salmonella enterica infections continue to be a significant burden on public health systems worldwide. As the S. enterica species comprises sublineages that differ greatly in antigenic representation, virulence, and antimicrobial resistance phenotypes, a better understanding of the species' evolution is critical for the prediction and prevention of future outbreaks. The roles that virulence and resistance phenotype acquisition, exchange, and loss play in the evolution of S. enterica sublineages, which to a certain extent are represented by serotypes, remains mostly uncharacterized. Here, we compare 17 newly sequenced and phenotypically characterized nontyphoidal S. enterica strains to 11 previously sequenced S. enterica genomes to carry out the most comprehensive comparative analysis of this species so far. These phenotypic and genotypic data comparisons in the phylogenetic species context suggest that the evolution of known S. enterica sublineages is mediated mostly by two mechanisms, (i) the loss of coding sequences with known metabolic functions, which leads to functional reduction, and (ii) the acquisition of horizontally transferred phage and plasmid DNA, which provides virulence and resistance functions and leads to increasing specialization. Matches between S. enterica clustered regularly interspaced short palindromic repeats (CRISPR), part of a defense mechanism against invading plasmid and phage DNA, and plasmid and prophage regions suggest that CRISPR-mediated immunity could control short-term phenotype changes and mediate long-term sublineage evolution. CRISPR analysis could therefore be critical in assessing the evolutionary potential of S. enterica sublineages and aid in the prediction and prevention of future S. enterica outbreaks.

Salmonella enterica continues to be a significant cause of foodborne gastrointestinal illness in humans. A wide variety of Salmonella serovars have been isolated from production birds and from retail poultry meat. Recently, though, S. enterica subsp. enterica serovar Kentucky has emerged as one of the prominent Salmonella serovars isolated from broiler chickens. Recent work suggests that its emergence apparently coincides with its acquisition of a ColV virulence plasmid. In the present study, we examined 902 Salmonella isolates belonging to 59 different serovars for the presence of this plasmid. Of the serovars examined, the ColV plasmid was found only among isolates belonging to the serovars Kentucky (72.9%), Typhimurium (15.0%) and Heidelberg (1.7%). We demonstrated that a single PFGE clonal type of S. Kentucky harbors this plasmid, and acquisition of this plasmid by S. Kentucky significantly increased its ability to colonize the chicken cecum and cause extraintestinal disease. Comparison of the completed sequences of three ColV plasmids from S. Kentucky isolated from different geographical locales, timepoints and sources revealed a nearly identical genetic structure with few single nucleotide changes or insertions/deletions. Overall, it appears that the ColV plasmid was recently acquired by a single clonal type S. Kentucky and confers to its host enhanced colonization and fitness capabilities. Thus, the potential for horizontal gene transfer of virulence and fitness factors to Salmonella from other enteric bacteria exists in poultry, representing a potential human health hazard.

A total of 360 spatially and temporally related Campylobacter isolates, including 168 from clinical human cases (Campylobacter jejuni n = 148; Campylobacter coli n = 20) and 192 from retail meats (C. jejuni n = 114; C. coli n = 78), were analyzed for antimicrobial susceptibilities, virulence, and genotypic profiles. Ciprofloxacin-resistant C. jejuni was observed in 13.5% and 19% of the isolates from humans and retail chicken breasts, respectively. Antimicrobial resistance to ciprofloxacin and erythromycin was detected in C. coli isolates recovered from 29% and 16.6% of retail meats and 15% and 5% humans, respectively. Overall, virulence determinants were more prevalent in Campylobacter isolates recovered from retail meats than from humans. C. jejuni isolates from humans were significantly associated with the rakR, dnaJ, and pld genes, whereas C. coli isolates from retail meats were associated with the dnaJ, pld, and virB11 virulence genes. Genotyping of 262 C. jejuni isolates using pulsed-field gel electrophoresis revealed a total of 186 unique SmaI patterns, with 14% of patterns composed of isolates recovered from retail meats and ill humans. All unique groups with indistinguishable SmaI patterns were further analyzed by a second restriction enzyme (KpnI), which revealed limited overlap between isolates from different sources. Significant association between doxycycline-resistant C. jejuni strains recovered from humans and different virulence genes (e.g., cdtB) was identified at the statistical level but not at the genotypic level. In conclusion, significant differences observed in the distribution of antimicrobial resistance profiles, virulence determinants, and genotypic diversity among C. jejuni and C. coli isolates indicate that there are sources other than retail meats that may also contribute to human Campylobacter infections.

Background: The testing of the implantable cardioverter-defibrillator (ICD), through the induction of repeated episodes of ventricular fibrillation, has been associated with disturbances in cerebral activity and increased levels of cytoplasmic enzymes. However, the neuropsychological outcomes of cerebral changes and their quality-of-life implications are unknown., Methods and Results: Fifty-two ICD recipients completed standardized validated neuropsychological tests 1 to 3 days before ICD surgery and then 6 weeks, 6 months, and 12 months after surgery. They also completed psychometric tests measuring anxiety, depression, and quality of life. Between 31% and 39% of patients showed a significant neuropsychological impairment from their baseline function 6 weeks, 6 months, and 12 months after surgery. Ten percent of patients had late-onset deficits at 12 months only. Frequent areas of impairment were auditory and visual memory and attention. Neuropsychological impairment was not related to mood or quality of life at follow-up, although anxiety and depression predicted reduced quality of life., Conclusions: ICD implantation is associated with neuropsychological impairment that dissipates for the majority of recipients after 12 months. Short-term memory function and attention are particularly vulnerable to changes in oxygen during ICD testing. Although anxiety and depression are prevalent, there is little evidence for the direct impact of mood on cognition, and deficits appear not to be associated with reduced quality of life. These results provide evidence for longitudinal outcomes of ICD surgery and have implications for patient rehabilitation and adjustment.

Although multidrug-resistant (MDR) non-Typhi Salmonella (NTS) strains are a concern in food production, determining resistance to multiple antimicrobial agents at slaughter or processing may be impractical. Single antimicrobial resistance results for predicting multidrug resistance are desirable. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value were used to determine each antimicrobial agent's ability to predict MDR phenotypes of human health significance: ACSSuT (resistance to at least ampicillin, chloramphenicol, streptomycin, sulfamethoxazole, tetracycline) in NTS isolates, and MDR-AmpC-SN (resistance to ACSSuT, additional resistance to amoxicillin-clavulanate and to ceftiofur, and decreased susceptibility [MIC >= 2 microg/ml] to ceftriaxone) in NTS serotype Newport. The U.S. National Antimicrobial Resistance Monitoring System determined MICs to 15 or more antimicrobial agents for 9,955 NTS isolates from humans from 1999 to 2004 and 689 NTS isolates from retail meat from 2002 to 2004. A total of 847 (8.5%) human and 26 (3.8%) retail NTS isolates were ACSSuT; 995 (10.0%) human and 16 (2.3%) retail isolates were serotype Newport. Among Salmonella Newport, 204 (20.5%) human and 9 (56.3%) retail isolates were MDR-AmpC-SN. Chloramphenicol resistance provided the highest PPVs for ACSSuT among human (90.5%; 95% confidence interval, 88.4 to 92.3) and retail NTS isolates (96.3%; 95% confidence interval, 81.0 to 99.9). Resistance to ceftiofur and to amoxicillin-clavulanate and decreased susceptibility to ceftriaxone provided the highest PPVs (97.1, 98.1, and 98.6%, respectively) for MDR-AmpC-SN from humans. High PPVs for these agents applied to retail meat MDR-AmpC-SN, but isolate numbers were lower. Variations in MIC results may complicate ceftriaxone's predictive utility. Selecting specific antimicrobial resistance offers practical alternatives for predicting MDR phenotypes. Chloramphenicol resistance works best for ACSSuT-NTS, and resistance to ceftiofur, amoxicillin-clavulanate, or chloramphenicol works best for MDR-AmpC-SN.

Background: The implantable cardioverter defibrillator (ICD) is a device used in the treatment of ventricular arrhythmias and the prevention of sudden cardiac death. However, the ICD has been associated with negative psychological outcomes such as anxiety, depression, panic, and poor quality of life (QoL). Recent studies suggest that the preimplantation psychology of patients, combined with their postimplantation perceptions about their cardiac condition, are greater contributory factors than their medical status to a poor outcome., Method: Our study employed an interview-based qualitative grounded theory methodology to explore whether medical history hetereogeneity and illness beliefs impact on the QoL of 13 ICD patients., Results: Perceived control emerged as the core category related to QoL with three subsystem themes related to control: (1) illness beliefs, attributions, and appraisals; (2) coping resources and strategies; and (3) the social world. Patients at risk for the poorest adaptation were younger (<45), unemployed, and with an acute onset cardiac history. These patients interpreted their illness as severe, utilized emotion-focused coping (e.g., avoidance of situations), and believed themselves to be socially excluded. Adjusted patients used proactive problem-focused coping (e.g., normalizing) and minimized consequences of the device., Conclusions: The data developed a theoretical model of QoL, which identified perceived control, illness beliefs, and coping impacting on adjustment. From our study, we have a wider understanding of the combination psychological issues relevant to ICD patients and are able to treat those at risk with interventions to promote adjustment in the context of a society that values health and well-being.

Salmonella continues to cause significant foodborne outbreaks, best illustrated with recent outbreaks associated with peanut butter, raw tomatoes, and serrano peppers. To ascertain the likely source of the outbreak, bacterial typing is essential to this process. While PCR has become an important detection tool for pathogens in foods, PCR can also identify strain differences by targeting gene(s) or sequences exhibiting polymorphisms or variability in its distribution within the bacterial population. Over 2,500 Salmonella enterica serovars identified based on antigenic differences in lipopolysaccharide and flagellin have been identified to date. We developed an allelotyping PCR scheme that identifies the O and H alleles associated with S. enterica serovars Enteritidis, Hadar, Heidelberg, Typhimurium, and others, with the same antigen alleles but in different O- and H-allele combinations (e.g., S. enterica Kentucky), and validated it as a screen to identify samples contaminated with these Salmonella serovars. We correctly identified poultry samples containing S. enterica serovars Enteritidis, Kentucky, and Typhimurium from our multiplex screen of primary enrichments of environmental drag swabs. PCR agreed well (kappa values = 0.81 to 1.0) with conventional serotyping methods used to type salmonellae isolated from primary enrichment. Coupled with Salmonella-specific PCR, such as invA, this allelotyping PCR could prove useful in the identification of Salmonella and specific S. enterica serovars present in foods or the environment and could decrease the time and cost associated with conventional serotyping methods.

Salmonella enterica, a leading cause of food-borne gastroenteritis worldwide, may be found in any raw food of animal, vegetable, or fruit origin. Salmonella serovars differ in distribution, virulence, and host specificity. Salmonella enterica serovar Kentucky, though often found in the food supply, is less commonly isolated from ill humans. The multidrug-resistant isolate S. Kentucky CVM29188, isolated from a chicken breast sample in 2003, contains three plasmids (146,811 bp, 101,461 bp, and 46,121 bp), two of which carry resistance determinants (pCVM29188&#95;146 [strAB and tetRA] and pCVM29188&#95;101 [bla(CMY-2) and sugE]). Both resistance plasmids were transferable by conjugation, alone or in combination, to S. Kentucky, Salmonella enterica serovar Newport, and Escherichia coli recipients. pCVM29188&#95;146 shares a highly conserved plasmid backbone of 106 kb (>90% nucleotide identity) with two virulence plasmids from avian pathogenic Escherichia coli strains (pAPEC-O1-ColBM and pAPEC-O2-ColV). Shared avian pathogenic E. coli (APEC) virulence factors include iutA iucABCD, sitABCD, etsABC, iss, and iroBCDEN. PCR analyses of recent (1997 to 2005) S. Kentucky isolates from food animal, retail meat, and human sources revealed that 172 (60%) contained similar APEC-like plasmid backbones. Notably, though rare in human- and cattle-derived isolates, this plasmid backbone was found at a high frequency (50 to 100%) among S. Kentucky isolates from chickens within the same time span. Ninety-four percent of the APEC-positive isolates showed resistance to tetracycline and streptomycin. Together, our findings of a resistance-conferring APEC virulence plasmid in a poultry-derived S. Kentucky isolate and of similar resistance/virulence plasmids in most recent S. Kentucky isolates from chickens and, to lesser degree, from humans and cattle highlight the need for additional research in order to examine the prevalence and spread of combined virulence and resistance plasmids in bacteria in agricultural, environmental, and clinical settings.

Multidrug resistance (MDR) plasmids belonging to the IncA/C plasmid family are widely distributed among Salmonella and other enterobacterial isolates from agricultural sources and have, at least once, also been identified in a drug-resistant Yersinia pestis isolate (IP275) from Madagascar. Here, we present the complete plasmid sequences of the IncA/C reference plasmid pRA1 (143,963 bp), isolated in 1971 from the fish pathogen Aeromonas hydrophila, and of the cryptic IncA/C plasmid pRAx (49,763 bp), isolated from Escherichia coli transconjugant D7-3, which was obtained through pRA1 transfer in 1980. Using comparative sequence analysis of pRA1 and pRAx with recent members of the IncA/C plasmid family, we show that both plasmids provide novel insights into the evolution of the IncA/C MDR plasmid family and the minimal machinery necessary for stable IncA/C plasmid maintenance. Our results indicate that recent members of the IncA/C plasmid family evolved from a common ancestor, similar in composition to pRA1, through stepwise integration of horizontally acquired resistance gene arrays into a conserved plasmid backbone. Phylogenetic comparisons predict type IV secretion-like conjugative transfer operons encoded on the shared plasmid backbones to be closely related to a group of integrating conjugative elements, which use conjugative transfer for horizontal propagation but stably integrate into the host chromosome during vegetative growth. A hipAB toxin-antitoxin gene cluster found on pRA1, which in Escherichia coli is involved in the formation of persister cell subpopulations, suggests persistence as an early broad-spectrum antimicrobial resistance mechanism in the evolution of IncA/C resistance plasmids.

Background: The origins and virulence potential of meat product-associated Escherichia coli are undefined., Methods: Two hundred eighty-seven E. coli isolates (145 resistant and 142 susceptible to trimethoprim-sulfamethoxazole, nalidixic acid, and/or ceftiofur), recovered by the United States National Antimicrobial Monitoring System from retail beef, pork, chicken, and turkey products (from Oregon, Tennessee, Georgia, and Maryland, 2002-2004) underwent polymerase chain reaction testing for phylogenetic groupings and 59 virulence-associated genes., Results: However analyzed, resistant and susceptible isolates differed minimally according to the assessed characteristics. In contrast, the 4 meat types differed greatly for multiple individual traits and aggregate virulence scores. Poultry isolates exhibited virulence genes associated with avian pathogenic E. coli; beef isolates exhibited traits associated with E. coli from diseased cattle. Overall, 20% of isolates qualified as extraintestinal pathogenic E. coli, with poultry isolates exhibiting significantly higher virulence scores than beef and pork isolates (P < .001)., Conclusions: Within this systematically collected, geographically distributed sample of recent retail meat isolates, the carriage of extraintestinal pathogenic E. coli virulence genes in antimicrobial-resistant and antimicrobial-susceptible E. coli appeared similar, whereas isolates from different types of meat differed, consistent with on-farm acquisition of resistance within host species-specific E. coli populations. A substantial minority of meat-source E. coli (whether susceptible or resistant) may represent potential human pathogens.

Extraintestinal pathogenic Escherichia coli (ExPEC) are major players in human urinary tract infections, neonatal bacterial meningitis, and sepsis. Recently, it has been suggested that there might be a zoonotic component to these infections. To determine whether the E. coli contaminating retail poultry are possible extraintestinal pathogens, and to ascertain the source of these contaminants, they were assessed for their genetic similarities to E. coli incriminated in colibacillosis (avian pathogenic E. coli [APEC]), E. coli isolated from multiple locations of apparently healthy birds at slaughter, and human ExPEC. It was anticipated that the retail poultry isolates would most closely resemble avian fecal E. coli since only apparently healthy birds are slaughtered, and fecal contamination of carcasses is the presumed source of meat contamination. Surprisingly, this supposition proved incorrect, as the retail poultry isolates exhibited gene profiles more similar to APEC than to fecal isolates. These isolates contained a number of ExPEC-associated genes, including those associated with ColV virulence plasmids, and many belonged to the B2 phylogenetic group, known to be virulent in human hosts. Additionally, E. coli isolated from the crops and gizzards of apparently healthy birds at slaughter also contained a higher proportion of ExPEC-associated genes than did the avian fecal isolates examined. Such similarities suggest that the widely held beliefs about the sources of poultry contamination may need to be reassessed. Also, the presence of ExPEC-like clones on retail poultry meat means that we cannot yet rule out poultry as a source of ExPEC human disease.

Aims: To determine the antimicrobial resistant profiles and clonality of Campylobacter coli isolated from clinically ill humans and retail meats., Methods and Results: A total of 98 C. coli isolates (20 from humans and 78 from retail meats) were phenotypically characterized. Antimicrobial susceptibility testing was done using agar dilution method for ciprofloxacin, gentamicin, erythromycin and doxycycline. Seventy C. coli isolates including humans (n = 20) and retail meats (n = 50) were genotyped by multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE). Resistance to ciprofloxacin was found in 29% and 15% of isolates from retail meats and humans. We observed 61 PFGE profiles using two enzymes (SmaI, KpnI) with an Index of discrimination of 0.99, whereas MLST generated 37 sequence types. Two clonal complexes were identified with 58 (82%) C. coli isolates clustered in the ST-828 complex., Conclusions: Resistance to ciprofloxacin and erythromycin was identified in C. coli obtained from retail meats and ill humans. PFGE typing of C. coli isolates was more discriminatory than MLST. Grouping of C. coli isolates (82%) by MLST in ST-828 clonal complex indicates a common ancestry., Significance and Impact of the Study: A high frequency of resistance found to ciprofloxacin and erythromycin is concerning from food safety perspective. PFGE using single or double restriction enzymes was found to be more discriminatory than MLST for genotyping C. coli. Overall, the C. coli populations recovered from humans and retail meats were genotypically diverse.

Fifty-eight Salmonella enterica serovar Heidelberg isolates isolated from food animals were tested for antimicrobial susceptibilities and further characterized for select antimicrobial resistance genes, plasmid carriage, class 1 integrons, and genetic relatedness using pulsed-field gel electrophoresis (PFGE). Seventy-two percent of isolates displayed resistance to at least one of the antimicrobial agents tested, while 24% exhibited resistance to eight or more antimicrobial agents. Resistance was most commonly observed to tetracycline (71%), streptomycin (62%), and kanamycin (52%). Isolates obtained from cattle and swine displayed the highest rates of resistance while isolates from chickens more often displayed susceptibility to the tested antimicrobials. When resistance was detected, a corresponding resistance gene was detected in 97.3% of the isolates. Thirteen percent of the isolates contained class 1 integrons containing at least one resistance gene, most often either the aadA or dhfrA genes, which are often associated with resistance to streptomycin and trimethoprim, respectively. Twenty isolates contained plasmids estimated to be at least 75 kb in size, 17 of which exhibited resistance to five or more antimicrobial agents. Thirty PFGE patterns were generated among the 58 isolates tested using XbaI, indicating extensive heterogeneity among this serotype across different animal origins. Results confirm the presence of multidrug-resistance (MDR) phenotypes among food animal isolates of serovar Heidelberg, especially those obtained from mammalian species. The observed MDR was typically associated with the presence of large plasmids.

Salmonella enterica serovar Heidelberg frequently causes food-borne illness in humans. There are few data on the prevalence, antimicrobial susceptibility, and genetic diversity of Salmonella serovar Heidelberg isolates in retail meats. We compared the prevalences of Salmonella serovar Heidelberg in a sampling of 20,295 meats, including chicken breast (n = 5,075), ground turkey (n = 5,044), ground beef (n = 5,100), and pork chops (n = 5,076), collected during 2002 to 2006. Isolates were analyzed for antimicrobial susceptibility and compared genetically using pulsed-field gel electrophoresis (PFGE) and PCR for the bla(CMY) gene. A total of 298 Salmonella serovar Heidelberg isolates were recovered, representing 21.6% of all Salmonella serovars from retail meats. One hundred seventy-eight (59.7%) were from ground turkey, 110 (36.9%) were from chicken breast, and 10 (3.4%) were from pork chops; none was found in ground beef. One hundred ninety-eight isolates (66.4%) were resistant to at least one compound, and 49 (16.4%) were resistant to at least five compounds. Six isolates (2.0%), all from ground turkey, were resistant to at least nine antimicrobials. The highest resistance in poultry isolates was to tetracycline (39.9%), followed by streptomycin (37.8%), sulfamethoxazole (27.7%), gentamicin (25.7%), kanamycin (21.5%), ampicillin (19.8%), amoxicillin-clavulanic acid (10.4%), and ceftiofur (9.0%). All isolates were susceptible to ceftriaxone and ciprofloxacin. All ceftiofur-resistant strains carried bla(CMY). PFGE using XbaI and BlnI showed that certain clones were widely dispersed in different types of meats and meat brands from different store chains in all five sampling years. These data indicate that Salmonella serovar Heidelberg is a common serovar in retail poultry meats and includes widespread clones of multidrug-resistant strains.

Background: Classical Salmonella serotyping is an expensive and time consuming process that requires implementing a battery of O and H antisera to detect 2,541 different Salmonella enterica serovars. For these reasons, we developed a rapid multiplex polymerase chain reaction (PCR)-based typing scheme to screen for the prevalent S. enterica serovars Enteritidis, Hadar, Heidelberg, and Typhimurium., Results: By analyzing the nucleotide sequences of the genes for O-antigen biosynthesis including wba operon and the central variable regions of the H1 and H2 flagellin genes in Salmonella, designated PCR primers for four multiplex PCR reactions were used to detect and differentiate Salmonella serogroups A/D1, B, C1, C2, or E1; H1 antigen types i, g, m, r or z10; and H2 antigen complexes, I: 1,2; 1,5; 1,6; 1,7 or II: e,n,x; e,n,z15. Through the detection of these antigen gene allele combinations, we were able to distinguish among S. enterica serovars Enteritidis, Hadar, Heidelberg, and Typhimurium. The assays were useful in identifying Salmonella with O and H antigen gene alleles representing 43 distinct serovars. While the H2 multiplex could discriminate between unrelated H2 antigens, the PCR could not discern differences within the antigen complexes, 1,2; 1,5; 1,6; 1,7 or e,n,x; e,n,z15, requiring a final confirmatory PCR test in the final serovar reporting of S. enterica., Conclusion: Multiplex PCR assays for detecting specific O and H antigen gene alleles can be a rapid and cost-effective alternative approach to classical serotyping for presumptive identification of S. enterica serovars Enteritidis, Hadar, Heidelberg, and Typhimurium.

Data on the prevalence of antimicrobial resistant enterococci and staphylococci from the poultry production environment are sparse in the United States. This information is needed for science-based risk assessments of antimicrobial use in animal husbandry and potential public-health consequences. In this study, we assessed the susceptibility of staphylococci and enterococci isolated from poultry litter, recovered from 24 farms across Georgia, to several antimicrobials of veterinary and human health importance. Among the 90 Enterococcus isolates recovered, E. hirae (46%) was the most frequently encountered species, followed by E. faecium (27%), E. gallinarum (12%), and E. faecalis (10%). Antimicrobial resistance was most often observed to tetracycline (96%), followed by clindamycin (90%), quinupristin-dalfopristin (62%), penicillin (53%), erythromycin (50%), nitrofurantoin (49%), and clarithromycin (48%). Among the 110 staphylococci isolates recovered, only coagulase-negative staphylococci (CNS) were identified with the predominant Staphylococcus species being S. sciuri (38%), S. lentus (21%), S. xylosus (14%) and S. simulans (12%). Resistance was less-frequently observed among the Staphylococcus isolates for the majority of antimicrobials tested, as compared with Enterococcus isolates, and was primarily limited to clarithromycin (71%), erythromycin (71%), clindamycin (48%), and tetracycline (38%). Multidrug resistance (MDR) phenotypes were prevalent in both Enterococcus and Staphylococcus; however, Enterococcus exhibited a statistically significant difference in the median number of antimicrobials to which resistance was observed (median = 5.0) compared with Staphylococcus species (median = 3.0). Because resistance to several of these antimicrobials in gram-positive bacteria may be attributed to the shuttling of common drug-resistance genes, we also determined which common antimicrobial-resistance genes were present in both enterococci and staphylococci. The antimicrobial resistance genes vat(D) and erm(B) were present in enterococci, vgaB in staphylococci, and mobile genetic elements Tn916 and pheromone-inducible plasmids were only identified in enterococci. These data suggest that the disparity in antimicrobial-resistance phenotypes and genotypes between enterococci and staphylococci isolated from the same environment is, in part, because of barriers preventing exchange of mobile DNA elements.

This study was conducted to determine the prevalence and antimicrobial resistance of Salmonella isolates recovered from processed poultry. Four hundred eighty pre- and postchill whole broiler chicken carcasses were collected from a poultry processing plant between July 2004 and June 2005. Water samples also were collected at the entrance and exit of the chiller. After preenrichment, carcass and water samples were analyzed for the presence of Salmonella using the automated BAX system followed by traditional culture methods. The proportions of pre- and postchill carcasses that were positive for Salmonella were 88.4 and 84.1%, respectively. Ninety-two percent of water samples collected at the entrance of the chiller were positive for Salmonella, but all exit samples were negative. There was no significant difference in the prevalence of Salmonella between pre- and postchill carcasses (P > 0.05). Salmonella isolates recovered were serotyped and tested for susceptibility to antimicrobials. Thirteen serotypes were identified; the most common were Salmonella Kentucky (59.5%) and Salmonella Typhimurium (17.8%). Three hundred thirty-nine (79.8%) of the isolates were resistant to at least one antimicrobial, and 53.4% were resistant to three or more antimicrobials. Resistance was most often observed to tetracycline (73.4% of isolates), ampicillin (52.9%), amoxicillin-clavulanic acid (52%), ceftiofur (51.7%), streptomycin (35.2%), and sulfisoxazole (21.8%). These results indicate the high prevalence of Salmonella contamination in whole broiler carcasses, and a large number of these Salmonella isolates were resistant to commonly used antimicrobials.

The use of antimicrobial agents in food animals can select for resistant bacterial pathogens that may be transmitted to humans via the commercial meat supply. In the USA, the FDA's Center for Veterinary Medicine regulatory duties require a determination that antimicrobial drugs are safe and effective for use in food animals. In addition, a qualitative assessment of risks to human health from antimicrobial resistance requires development. This risk assessment process is supported by data generated by the FDA's National Antimicrobial Resistance Monitoring System (NARMS) for enteric bacteria. NARMS data on antimicrobial susceptibility among Salmonella, Campylobacter, Escherichia coli and Enterococcus is collected. Research activities defining the genetic bases of resistance helps to understand the potential public health risks posed by the spread of antimicrobial resistance from food animal antimicrobial use. These activities help insure that antimicrobials are used judiciously to promote human and animal health.

Three hundred and eighty Salmonella isolates recovered from animal diagnostic samples obtained from four state veterinary diagnostic laboratories (AZ, NC, MO, and TN) between 2002 and 2003 were tested for antimicrobial susceptibilities and further characterized for bla(CMY) beta-lactamase genes, class 1 integrons and genetic relatedness using PFGE. Forty-seven serovars were identified, the most common being S. Typhimurium (26%), S. Heidelberg (9%), S, Dublin (8%), S. Newport (8%), S. Derby (7%), and S. Choleraesuis (7%). Three hundred and thirteen (82%) isolates were resistant to at least one antimicrobial, and 265 (70%) to three or more antimicrobials. Resistance was most often observed to tetracycline (78%), followed by streptomycin (73%), sulfamethoxazole (68%), and ampicillin (54%), and to a lesser extent chloramphenicol (37%), kanamycin (37%), amoxicillin-clavulanic acid (20%), and ceftiofur (17%). With regards to animal of origin, swine Salmonella isolates displayed the highest rate of resistance, being resistant to at least one antimicrobial (92%), followed by those recovered from turkey (91%), cattle (77%), chicken (68%), and equine (20%). Serovars commonly showing multidrug resistance (MDR) to > or =9 antimicrobials were S. Uganda (100%), S. Agona (79%), and S. Newport (62%), compared to S. Heidelberg (11%) and S. Typhimurium (7%). Class-1 integrons were detected in 43% of all isolates, and were found to contain aadA, aadB, dhfr, cmlA and sat1 gene cassettes alone or in various combinations. All ceftiofur resistant isolates (n=66) carried the bla(CMY) beta-lactamase gene. A total of 230 PFGE patterns were generated among the 380 isolates tested using XbaI, indicating extensive genetic diversity across recovered Salmonella serovars, however, several MDR clones were repeatedly recovered from different diseased animals.

We compared 581 Salmonella enterica serotype Schwarzengrund isolates from persons, food, and food animals in Denmark, Thailand, and the United States by antimicrobial drug susceptibility and pulsed-field gel electrophoresis (PFGE) typing. Resistance, including resistance to nalidixic acid, was frequent among isolates from persons and chickens in Thailand, persons in the United States, and food imported from Thailand to Denmark and the United States. A total of 183 PFGE patterns were observed, and 136 (23.4%) isolates had the 3 most common patterns. Seven of 14 isolates from persons in Denmark had patterns found in persons and chicken meat in Thailand; 22 of 390 human isolates from the United States had patterns found in Denmark and Thailand. This study suggests spread of multidrug-resistant S. Schwarzengrund from chickens to persons in Thailand, and from imported Thai food products to persons in Denmark and the United States.

Antimicrobial resistance in Yersinia pestis is rare, yet constitutes a significant international public health and biodefense threat. In 1995, the first multidrug resistant (MDR) isolate of Y. pestis (strain IP275) was identified, and was shown to contain a self-transmissible plasmid (pIP1202) that conferred resistance to many of the antimicrobials recommended for plague treatment and prophylaxis. Comparative analysis of the DNA sequence of Y. pestis plasmid pIP1202 revealed a near identical IncA/C plasmid backbone that is shared by MDR plasmids isolated from Salmonella enterica serotype Newport SL254 and the fish pathogen Yersinia ruckeri YR71. The high degree of sequence identity and gene synteny between the plasmid backbones suggests recent acquisition of these plasmids from a common ancestor. In addition, the Y. pestis pIP1202-like plasmid backbone was detected in numerous MDR enterobacterial pathogens isolated from retail meat samples collected between 2002 and 2005 in the United States. Plasmid-positive strains were isolated from beef, chicken, turkey and pork, and were found in samples from the following states: California, Colorado, Connecticut, Georgia, Maryland, Minnesota, New Mexico, New York and Oregon. Our studies reveal that this common plasmid backbone is broadly disseminated among MDR zoonotic pathogens associated with agriculture. This reservoir of mobile resistance determinants has the potential to disseminate to Y. pestis and other human and zoonotic bacterial pathogens and therefore represents a significant public health concern.

ABSTRACT Fusarium verticillioides, F. proliferatum, and Aspergillus flavus cause ear rots of maize and contaminate the grain with mycotoxins (fumonisin or aflatoxin). The objective of this study was to investigate the relationships between resistance to Fusarium and Aspergillus ear rots and fumonisin and aflatoxin contamination. Based on a previous study of 143 recombinant inbred lines from the cross NC300 x B104, 24 lines with the highest and 24 lines with the lowest mean fumonisin concentration were selected for further evaluation. Paired plots of each line were inoculated with F. verticillioides and F. proliferatum or with A. flavus in replicated trials in 2004 and 2005 in Clayton, NC, and College Station, TX. The low-fumonisin group had significantly lower levels of fumonisin, aflatoxin, and Fusarium and Aspergillus ear rots. Across year-location environments, all four traits were significantly correlated; the genotypic correlation (r(G)) ranged from r(G) = 0.88 (aflatoxin and Aspergillus ear rot) to r(G) = 0.99 (Fusarium and Aspergillus ear rots). Quantitative trait loci (QTLs) were identified and their effects estimated. Two QTLs affected both toxin concentrations, one QTL affected both ear rots, and one QTL affected Aspergillus and Fusarium rots and fumonisin. These results suggest that at least some of the genes involved in resistance to ear rots and mycotoxin contamination are identical or genetically linked.

Despite the critical role of plasmids in horizontal gene transfer, few studies have characterized plasmid relatedness among different bacterial populations. Recently, a multiplex PCR replicon typing protocol was developed for classification of plasmids occurring in members of the Enterobacteriaceae. Here, a simplified version of this replicon typing procedure which requires only three multiplex panels to identify 18 plasmid replicons is described. This method was used to screen 1,015 Escherichia coli isolates of avian, human, and poultry meat origin for plasmid replicon types. Additionally, the isolates were assessed for their content of several colicin-associated genes. Overall, a high degree of plasmid variability was observed, with 221 different profiles occurring among the 1,015 isolates examined. IncFIB plasmids were the most common type identified, regardless of the source type of E. coli. IncFIB plasmids occurred significantly more often in avian pathogenic E. coli (APEC) and retail poultry E. coli (RPEC) than in uropathogenic E. coli (UPEC) and avian and human fecal commensal E. coli isolates (AFEC and HFEC, respectively). APEC and RPEC were also significantly more likely than UPEC, HFEC, and AFEC to possess the colicin-associated genes cvaC, cbi, and/or cma in conjunction with one or more plasmid replicons. The results suggest that E. coli isolates contaminating retail poultry are notably similar to APEC with regard to plasmid profiles, with both generally containing multiple plasmid replicon types in conjunction with colicin-related genes. In contrast, UPEC and human and avian commensal E. coli isolates generally lack the plasmid replicons and colicin-related genes seen in APEC and RPEC, suggesting limited dissemination of such plasmids among these bacterial populations.

The mechanisms involved in fluoroquinolone resistance in Salmonella enterica include target alterations and overexpression of efflux pumps. The present study evaluated the role of known and putative multidrug resistance efflux pumps and mutations in topoisomerase genes among laboratory-selected and naturally occurring fluoroquinolone-resistant Salmonella enterica serovar Typhimurium strains. Strains with ciprofloxacin MICs of 0.25, 4, 32, and 256 microg/ml were derived in vitro using serovar Typhimurium S21. These mutants also showed decreased susceptibility or resistance to many nonfluoroquinolone antimicrobials, including tetracycline, chloramphenicol, and several beta-lactams. The expression of efflux pump genes acrA, acrB, acrE, acrF, emrB, emrD, and mdlB were substantially increased (>or=2-fold) among the fluoroquinolone-resistant mutants. Increased expression was also observed, but to a lesser extent, with three other putative efflux pumps: mdtB (yegN), mdtC (yegO), and emrA among mutants with ciprofloxacin MICs of >or=32 microg/ml. Deletion of acrAB or tolC in S21 and its fluoroquinolone-resistant mutants resulted in increased susceptibility to fluoroquinolones and other tested antimicrobials. In naturally occurring fluoroquinolone-resistant serovar Typhimurium strains, deletion of acrAB or tolC increased fluoroquinolone susceptibility 4-fold, whereas replacement of gyrA double mutations (S83F D87N) with wild-type gyrA increased susceptibility>500-fold. These results indicate that a combination of topoisomerase gene mutations, as well as enhanced antimicrobial efflux, plays a critical role in the development of fluoroquinolone resistance in both laboratory-derived and naturally occurring quinolone-resistant serovar Typhimurium strains.

Gibberella ear rot, caused by Gibberella zeae, has increased in prevalence recently on lateseason processing sweet corn grown in North America. Little information is available about the development of Gibberella ear rot on processing sweet corn hybrids over extended periods of harvest. In five trials from 2003 to 2005, 12 processing sweet corn hybrids were inoculated with G. zeae and evaluated for severity of Gibberella ear rot on sequential harvest dates from 19 to 27 days after midsilk. Ear rot severity was assessed using a rating scale based on the percentage of kernels with visible symptoms of G. zeae colonization including kernel rot and mycelial growth. Severity ranged from 1.6 to 47.8% over the five trials. None of the hybrids was highly resistant to Gibberella ear rot, although some appeared to be less susceptible. Gibberella ear rot was less severe on three hybrids (GH 2690, GG 147, and Sprint) and more severe on three hybrids (GG 42, GG 145, and Jubilee). Other hybrids had moderate levels of ear rot or responses that varied among years. The relative response of hybrids did not change substantially during the extended period of harvest; however, the rate at which Gibberella ear rot developed on hybrids differed in 2003 and 2005 as reflected by a significant hybrid by harvest interaction. The interaction was primarily the result of Gibberella ear rot developing more severely on susceptible hybrids than on the less susceptible hybrids. The difference in Gibberella development could be exploited to limit losses due to this disease under certain circumstances. If a sweet corn processor had several fields ready to harvest at the same time, and some fields were planted with hybrids that are more susceptible while other fields were planted with hybrids that are less susceptible, losses due to Gibberella ear rot might be minimized by harvesting the most susceptible hybrids first. Other hybrids that might be best suited for early or late harvest can be identified from Gibberella ear rot ratings 28 days after silk channel inoculation at the midsilk growth stage.