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We experimentally infected Amblyomma aureolatum ticks with the bacterium Rickettsia rickettsii, the etiologic agent of Rocky Mountain spotted fever (RMSF). These ticks are a vector for RMSF in Brazil. R. rickettsii was efficiently conserved by both transstadial maintenance and vertical (transovarial) transmission to 100% of the ticks through 4 laboratory generations. However, lower reproductive performance and survival of infected females was attributed to R. rickettsii infection. Therefore, because of the high susceptibility of A. aureolatum ticks to R. rickettsii infection, the deleterious effect that the bacterium causes in these ticks may contribute to the low infection rates (<1%) usually reported among field populations of A. aureolatum ticks in RMSF-endemic areas of Brazil. Because the number of infected ticks would gradually decrease after each generation, it seems unlikely that A. aureolatum ticks could sustain R. rickettsii infection over multiple successive generations solely by vertical transmission. [ABSTRACT FROM AUTHOR]

Background: Marsupials and rodents are the most important wild and synanthropic hosts of Trypanosoma cruzi due to the high frequency of infection, maintenance of diverse genetic populations of the parasite, and their close proximity to interact with both transmission cycles, sylvatic and peridomestic. Our aim was to identify the discrete typing units (DTU) of T. cruzi from different wild and synanthropic hosts in two regions of Mexico and to carry out a review of historical data focusing on current knowledge on the diversity and T. cruzi DTUs of host species. Materials and Methods: One hundred fifteen samples were obtained from two areas in Tabasco and Nayarit state. The presence of T. cruzi was evaluated by PCR. Results: The 12.6% (12/95) of samples from Tabasco and 65% (13/20) from Nayarit were found to be positive for parasite DNA. All the sequences analyzed were grouped in T. cruzi DTU I; low nucleotide diversity was observed in Tabasco (π = 0.00566, and ϴ = 0.00632), while high genetic diversity was observed in Nayarit sequences, up to 8.63 (π) to 11.10 (ϴ) times greater than Tabasco sequences. Genetic flow and migration between Tabasco, and Nayarit were scarce (FST = 0.37329 and Nm = 0.42), and genetic exchange was observed only between nearby areas. The bibliographic review of hosts in Mexico, together with our data, shows a heterogeneous T. cruzi prevalence in Chiroptera and domestic animals. For Atelidae and Canids, prevalence is generally below 25%. However, a high prevalence, greater than 25% and up to 100%, was recorded in Didelphimorphia, and Rodentia. Few studies in regions of Mexico have been described as infected with the parasite; in these, the genetic group with the highest prevalence is the DTU I. Conclusion: Marsupials and rodents are important reservoirs of T. cruzi; DTU I was frequently reported; however, recent genetic and reservoir studies have demonstrated the presence of greater diversity of genetic groups. [ABSTRACT FROM AUTHOR]

Background: Canine acaricides with rapid onset and sustained activity can reduce pathogen transmission risk and enhance pet owner experience. This randomized, complete block design, investigator-masked study compared the speed of kill of Amblyomma americanum provided by three monthly-use isoxazoline-containing products. Methods: Eight randomized beagles per group were treated (day 0), per label, with sarolaner (combined with moxidectin and pyrantel, Simparica Trio™), afoxolaner (NexGard™), or lotilaner (Credelio™), or remained untreated. Infestations with 50 adult A. americanum were conducted on days − 7, − 2, 21, and 28, and tick counts were performed on day − 5 (for blocking), and at 4, 8, 12, 24, 48, and 72 h following treatment and subsequent infestations. Efficacy calculations were based on geometric mean live tick counts. A linear mixed model was used for between-group comparisons. Results: On day 0, only lotilaner significantly reduced an A. americanum infestation by 12 h (43.3%; P = 0.002). Efficacy of lotilaner and afoxolaner at 24 h post-treatment was 95.3% and 97.6%, respectively, both significantly different from sarolaner (74%) (P = 0.002, P < 0.001, respectively). On day 21, at 12 h postinfestation, lotilaner efficacy (59.6%) was significantly different from sarolaner (0.0%) (P < 0.001) and afoxolaner (6.3%) (P < 0.001). At 24 h, lotilaner efficacy (97.4%) was significantly different (P < 0.001) from sarolaner and afoxolaner (13.6% and 14.9%, respectively). On day 28, at 12 h postinfestation, lotilaner efficacy (47.8%) was significantly different from sarolaner (17.1%) (P = 0.020) and afoxolaner (9.0%) (P = 0.006). At 24 h, lotilaner efficacy (92.3%) was significantly different from sarolaner 4.9% (P < 0.001) and afoxolaner (0.0%) (P < 0.001). Speed of kill for sarolaner and afoxolaner, but not lotilaner, significantly declined over the study period. Following reinfestation on day 28, neither sarolaner nor afoxolaner reached 90% efficacy by 48 h. By 72 h, sarolaner efficacy was 97.4% and afoxolaner efficacy was 86.3%. Only lotilaner achieved ≥ 90% efficacy by 24 h post-treatment and 24 h postinfestation on days 21 and 28. Time to ≥ 90% efficacy following new infestations consistently occurred 24–48 h earlier for lotilaner compared with sarolaner or afoxolaner. Conclusions: Credelio (lotilaner) has a more rapid onset of acaricidal activity against A. americanum than Simparica Trio (sarolaner-moxidectin-pyrantel) and NexGard (afoxolaner). Only lotilaner's speed of tick kill is sustained throughout the dosing period. [ABSTRACT FROM AUTHOR]

Amblyomma ticks are vectors of both Rickettsia rickettsii and R. parkeri in the Americas, where capybaras (Hydrochoerus hydrochaeris) are the main hosts in urban areas, thus contributing to the transmission of spotted fever. Herein, we studied: (i) the seasonal dynamics and abundance of ticks in areas where capybaras live, (ii) the effect of environmental variables on tick abundance, and (iii) the presence of Rickettsia-infected ticks. Between September 2021 and September 2022, we sampled ticks using cloth-dragging at 194 sites on the shore of Lake Paranoá in Brasília, Brazil. We measured environmental data (season, vegetation type, canopy density, temperature, humidity, and presence or vestige of capybara) at each site. Nymphs and adults were morphologically identified to the species level, and a selected tick sample including larvae was subjected to genotypic identification. We investigated Rickettsia-infected ticks by PCR (gltA, htrA, ompB, and ompA genes) and associations between tick abundance and environmental variables using Generalized Linear Models. A total of 30,334 ticks (96% larvae) were captured. Ticks were identified as Amblyomma, with A. sculptum comprising 97% of the adult/nymphs. Genotype identification of a larval sample confirmed that 95% belonged to A. dubitatum. Seasonal variables showed significant effects on tick abundance. Most larvae and nymphs were captured during the early dry season, while the adults were more abundant during the wet season. Vegetation variables and the presence of capybaras showed no association with tick abundance. Rickettsia parkeri group and R. bellii were identified in A. dubitatum, while A. sculptum presented R. bellii. We conclude that: (i) Amblyomma ticks are widely distributed in Lake Paranoá throughout the year, especially larvae at the dry season, (ii) the abundance of Amblyomma ticks is explained more by climatic factors than by vegetation or presence of capybaras, and (iii) A. dubitatum ticks are potential vectors of R. parkeri in Brasília. [ABSTRACT FROM AUTHOR]

Background: Hyalomma ticks are widely distributed in semi-arid zones in Northwest China. They have been reported to harbor a large number of zoonotic pathogens. Methods: In this study, a total of 334 Hyalomma asiaticum ticks infesting domestic animals were collected from four locations in Xinjiang, Northwest China, and the bacterial agents in them were investigated. Results: A putative novel Borrelia species was identified in ticks from all four locations, with an overall positive rate of 6.59%. Rickettsia sibirica subsp. mongolitimonae, a human pathogen frequently reported in Europe, was detected for the second time in China. Two Ehrlichia species (Ehrlichia minasensis and Ehrlichia sp.) were identified. Furthermore, two Anaplasma species were characterized in this study: Candidatus Anaplasma camelii and Anaplasma sp. closely related to Candidatus Anaplasma boleense. It is the first report of Candidatus Anaplasma camelii in China. Conclusions: Six bacterial agents were reported in this study, many of which are possible or validated pathogens for humans and animals. The presence of these bacterial agents may suggest a potential risk for One Health in this area. [ABSTRACT FROM AUTHOR]

Background: The study of parasites provides insight into intricate ecological relationships in ecosystem dynamics, food web structures, and evolution on multiple scales. Hepatozoon Eucoccidiorida: Hepatozoidae) is a genus of protozoan hemoparasites with heteroxenous life cycles that switch infections between vertebrates and blood-feeding invertebrates. The most comprehensive review of the genus was published 26 years ago, and currently there are no harmonized data on the epizootiology, diagnostics, genotyping methods, evolutionary relationships, and genetic diversity of Hepatozoon in the Americas. Methods: Here, we provide a comprehensive review based on the PRISMA method regarding Hepatozoon in wild mammals within the American continent, in order to generate a framework for future research. Results: 11 out of the 35 countries of the Americas (31.4%) had data on Hepatozoon, with Carnivora and Rodentia orders having the most characterizations. Bats, ungulates, and shrews were the least affected groups. While Hepatozoon americanum, H. americanum-like, H. canis, H. didelphydis, H. felis, H. milleri, H. griseisciuri, and H. procyonis correspond to the identified species, a plethora of genospecies is pending for a formal description combining morphology and genetics. Most of the vectors of Hepatozoon in the Americas are unknown, but some flea, mite, and tick species have been confirmed. The detection of Hepatozoon has relied mostly on conventional polymerase chain reaction (PCR), and the implementation of specific real time PCR for the genus needs to be employed to improve its diagnosis in wild animals in the future. From a genetic perspective, the V4 region of the 18S rRNA gene has been widely sequenced for the identification of Hepatozoon in wild animals. However, mitochondrial and apicoplast markers should also be targeted to truly determine different species in the genus. A phylogenetic analysis of herein retrieved 18S ribosomal DNA (rDNA) sequences showed two main clades of Hepatozoon: Clade I associated with small mammals, birds, and herpetozoa, and Clade II associated with Carnivora. The topology of the tree is also reflected in the haplotype network. Conclusions: Finally, our review emphasizes Hepatozoon as a potential disease agent in threatened wild mammals and the role of wild canids as spreaders of Hepatozoon infections in the Americas. [ABSTRACT FROM AUTHOR]

Background: The appropriate mineral nutrients are essential for sheep growth and reproduction. However, traditional grazing sheep often experience mineral nutrient deficiencies, especially copper (Cu), due to inadequate mineral nutrients from natural pastures. Results: The results indicated that dietary Cu deficiency and supplementation significantly reduced and elevated liver concentration of Cu, respectively (p < 0.05). FOXO3, PLIN1, ACTN2, and GHRHR were identified as critical genes using the weighted gene co-expression network analysis (WGCNA), quantitative real-time polymerase chain reaction (qRT-PCR), and receiver operating characteristic curve (ROC) validation as potential biomarkers for evaluating Cu status in grazing sheep. Combining these critical genes with gene functional enrichment analysis, it was observed that dietary Cu deficiency may impair liver regeneration and compromise ribosomal function. Conversely, dietary Cu supplementation may enhance ribosomal function, promote lipid accumulation, and stimulate growth and metabolism in grazing sheep. Metabolomics analysis indicated that dietary Cu deficiency significantly decreased the abundance of metabolites such as cholic acid (p < 0.05). On the other hand, dietary Cu supplementation significantly increased the abundance of metabolites such as palmitic acid (p < 0.05). Integrative analysis of the transcriptome and metabolome revealed that dietary Cu deficiency may reduce liver lipid metabolism while Cu supplementation may elevate it in grazing sheep. Conclusions: The Cu content in diets may have an impact on hepatic lipid metabolism in grazing sheep. These findings provide new insights into the consequences of dietary Cu deficiency and supplementation on sheep liver and can provide valuable guidance for herders to rationalize the use of mineral supplements. [ABSTRACT FROM AUTHOR]

Toxoplasma gondii is an intracellular parasite with a worldwide distribution. Toxoplasma gondii infections are of great concern for public health, and their impact is usually most severe in pregnant women and their foetuses, and in immunocompromised individuals. Displaying considerable genetic diversity, T. gondii strains differ widely according to geographical location, with archetypal strains predominantly found in the Northern Hemisphere and non-archetypal (atypical) strains, with highly diverse genotypes, found mainly in South America. In this review, we present an overview of the identification and distribution of non-archetypal strains of T. gondii. Special attention is paid to the strains that have been isolated in Brazil, their interaction with the host immunological response, and their impact on disease outcomes. The genetic differences among the strains are pivotal to the distinct immunological responses that they elicit. These differences arise from polymorphisms of key proteins released by the parasite, which represent important virulence factors. Infection with divergent non-archetypal strains can lead to unusual manifestations of the disease, even in immunocompetent individuals. [ABSTRACT FROM AUTHOR]

Background Compliant ectoparasiticide product use is a comprehensive way to control ticks and reduce the risk of tick-borne pathogen transmission to dogs. Because the systemically acting isoxazoline ectoparasiticides require tick attachment for drug delivery, fast speed of kill is essential to minimize tick-borne pathogen transmission risk. Methods Dogs of satisfactory tick-carrying capacity were randomly allocated to treatment groups and administered, per label instructions, Bravecto® Chews (minimum 25 mg/kg furalaner), Simparica TRIO® (minimum 1.2 mg/kg sarolaner, 24 µg/kg moxidectin, 5 mg/kg pyrantel), or no treatment. Dogs were infested with approximately 50 unfed adult (35 female, 15 male) Ixodes scapularis on Day -2, 21 and 28. Live tick counts were performed at 4, 8, 12 and 24 h post-treatment (Day 0) and post-infestation on Day 21 and 28. Tick control efficacy was determined by comparing live tick means for each product-treated group to the untreated control group and each other at all time points using a linear mixed model. The percent of dogs free of live ticks was analyzed using the Fisher’s exact test for treatment group comparison. Results The untreated control group maintained adequate tick infestations throughout the study. Using geometric means, an existing I. scapularis infestation was controlled by 99.7% and 93.0% 12 h post-treatment and by 100% and 99.5% 24 h post-treatment, for Bravecto® and Simparica TRIO®-treated dogs, respectively. Ixodes scapularis infestations were controlled more quickly for Bravecto®- compared to Simparica TRIO®-treated dogs on Day 21 at 8 h (efcacy 74.0% vs. 0.0%, p=0.003) and 12 h (efficacy 99.2% vs. 39.4%, p<0.001) post-infestation and Day 28 at 8 h (efficacy 92.2% vs. 0.0%, p<0.001) and 12 h (efcacy 99.6% vs. 27.7%, p<0.001) post-infestation. On Day 28 post-treatment, the efficacy of Bravecto® and Simparica TRIO® to control a new I. scapularis infestation was 100% and 96.6%, respectively, by 24 h post-infestation. Of product-treated dogs, 100% of Bravecto®-treated dogs were free of live ticks by 24 h post-treatment or post-infestation. No treatment-related adverse reactions occurred during the study. Conclusions Ixodes scapularis infestations are controlled more quickly 21 and 28 days post-treatment for dogs administered a single dose of Bravecto® compared to dogs administered a single dose of Simparica TRIO®. [ABSTRACT FROM AUTHOR]

Background: The tick Amblyomma cajennense sensu stricto (A. cajennense s.s.) frequently parasitizes animals and humans in the Amazon biome, in addition to being a vector of Rickettsia amblyommatis. In the present study, we evaluated both the population dynamics of A. cajennense s.s. in a degraded area of the Amazon biome and the presence of rickettsial organisms in this tick population. Methods: The study was carried out in a rural area of the Santa Inês municipality (altitude: 24 m a.s.l.), Maranhão state, Brazil. Ticks were collected from the environment for 24 consecutive months, from June 2021 to May 2023. The region is characterized by two warm seasons: a rainy season (November–May) and a dry season (June–October). We characterized the temporal activity of A. cajennense s.s. on the vegetation by examining questing activity for each life stage (larvae, nymphs, adults [males and females]) in relation to the dry and rainy season. Ticks collected in this study were randomly selected and individually tested by a TaqMan real-time PCR assay that targeted a 147-bp fragment of the rickettsial gltA gene. Results: Overall, 1843 (62.4%) adults (52.6% females, 47.4% males), 1110 (37.6%) nymphs and 398 larval clusters were collected. All adult females and nymphs were morphologically identified as A. cajennense s.s. Larval activity was observed from April to December, with a peak from June to September (dry season); nymph abundance peaked from September to November (transition period between dry and rainy seasons); and adult ticks were abundant from October to May (spring/summer/early autumn). The infection rate by R. amblyommatis in A. cajennense s.s. ticks was at least 7% (7/99). Conclusion: Our data suggest a 1-year generation pattern for A. cajennense s.s., with a well-defined seasonality of larvae, nymphs and adults in the Amazon biome. Larvae predominate during the dry season, nymphs are most abundant in the dry-rainy season transition and adults are most abundant in the rainy season. The presence of R. amblyommatis in adult ticks suggests that animals and humans in the study region are at risk of infection by this species belonging to the spotted fever group of Rickettsia. [ABSTRACT FROM AUTHOR]

We report Rickettsia species from 2,334 ticks collected from environment (1,939 ticks) and animals (395 ticks) in the largest inland fragment of the Atlantic rainforest of southern Brazil and its fragments. Additionally, the DNA infection rates of Amblyomma ovale tick populations in the Neotropics with Rickettsia bellii and Rickettsia parkeri strain Atlantic rainforest were calculated using data from scientific publications, and their correlation was evaluated. From 11 tick species Rickettsia DNA was detected in seven (Amblyomma brasiliense, Amblyomma coelebs, Amblyomma incisum, Amblyomma longirostre, A. ovale, Haemaphysalis juxtakochi, Ixodes fuscipes) and was not detected in four species (Amblyomma dubitatum, Ixodes loricatus, Rhipicephalus microplus and Rhipicephalus sanguineus sensu lato). DNA of five Rickettsia species was detected (R. bellii, Rickettsia amblyommatis, Rickettsia rhipicephali, Rickettsia felis and Rickettsia sp. Aragaoi). To determine the prevalence of Rickettsia DNA positivity according to vector species, ticks were processed individually or in pools of 2–10 individuals (samples). The most prevalent Rickettsia species was R. bellii, found in 112 samples, followed by R. amblyommatis, R. rhipicephali, R. felis and Rickettsia sp. Aragaoi, found in 16, five, two and one sample, respectively. Rickettsia bellii DNA was found in five tick species with the highest infection rate in A. ovale and A. brasiliense. Absence of R. parkeri strain Atlantic rainforest in A. ovale ticks was an unexpected result. Furthermore, a negative correlation was identified between the infection rates (DNA) of R. bellii and/or R. parkeri strain Atlantic rainforest within A. ovale tick populations in the Neotropics. Putting together current knowledge, it can be proposed that, within natural settings, the diversity of rickettsiae and ticks creates a buffering effect on the overgrowth of rickettsiae and episodes of bacteremia in the hosts. [ABSTRACT FROM AUTHOR]

Background: There are few reports of tick-borne pathogens infecting dogs living in indigenous communities of Brazil. Herein, we aimed to molecularly detect vector-borne pathogens in dogs from two indigenous communities in the Brazilian Amazon. Materials and Methods: We surveyed 327 dogs raised in Amazon region at 2 distinct indigenous ethnicities for the molecular detection of tick-borne pathogens (114 from Tapirapé and 213 from Karajá indigenous ethnicity). Whole blood samples were subjected to PCR and sequencing for Ehrlichia, Babesia, and Hepatozoon. Univariate and multivariate analyses were used to investigate the factors affecting the pathogen infection patterns in dogs. Results: Among the 327 blood samples, 40 were positive for Ehrlichia canis (12.2%), 2 for Anaplasma platys (0.61%), and 204 were positive for Hepatozoon canis (66.5%). Binary Logistic Regression showed association between E. canis infection and ethnicity (p = 0.010) and tick attachment (p = 0.041). Karajá dogs were 3.4 times (95% CI 1.3–8.5) more likely to be positive for E. canis than Tapirapé dogs. Dogs with ticks were 2.5 times more likely (95% CI 1.0–7.6) to be positive for E. canis than dogs without ticks. Conclusions: Our survey expands the knowledge regarding the presence of vector-borne pathogens in dogs from indigenous communities in the Amazon region. [ABSTRACT FROM AUTHOR]

Background: The order Rickettsiales contains a group of vector-borne gram-negative obligate intracellular bacteria, which often cause human emerging infectious diseases and economic losses for dairy and meat industries. The purpose of this study is to investigate the distribution of the pathogens including Rickettsia spp., Anaplasma spp., and Ehrlichia spp. in the order Rickettsiales in ticks from Yueyang, a prefecture-level city of Hunan Province in Sothern China, and assess the potentiality of transovarial transmission of these rickettsial organisms. Methods: Ticks were collected from cattle in a farm in Yueyang City and the tick DNA was used as template to amplify the htrA, rrs, gltA, ompA and ompB genes of Rickettsia as well as rrs and groEL genes of Anaplasma and Ehrlichia. Results: All ticks (465) collected were the cattle tick, Rhipicephalus microplus. PCR showed the minimum infection rate (MIR) was 1.5% (7/465) for Candidatus Rickettsia xinyangensis, 1.9% (9/465) for C. Anaplasma boleense, 1.3% (6/465) for Anaplasma platys, 0.6% (3/465) for A. marginale, and 1.17% (2/465) for each of A. bovis, Ehrlichia minasensis, and a non-classified Ehrlichia sp. A human pathogen, C. Rickettsia xinyangensis and A. platys were detected in 100% (3/3) and 33.3% (2/6) laboratory-hatched larval pools from infected females respectively. Conclusion: Our study revealed a diversity of pathogenic rickettsial species in R. microplus ticks from Hunan Province suggesting a threat to people and animals in China. This study also provided the first molecular evidence for the potential transovarial transmission of C. Rickettsia xinyangensis and A. platys in R. microplus, indicating that R. microplus may act as the host of these two pathogens. Author summary: Spotted fever group rickettsiae, Anapalsma, and Ehrlichia are tick-borne bacteria, which can cause severe human and animal infection and/or extensive economic losses in animal husbandry. It has been well documented that some Ixodidae ticks are able to transmit Rickettsia, Anaplasma, and Ehrlichia, while the studies on transovarial transmission are limited. In this study, we detected 7 rickettsial species in the cattle tick Rhipicephalus microplus in Hunan Province of the Southern China. Among them, Candidatus Rickettsia xinyangensis and A. platys were also found in the tick eggs and laboratory-hatched larvae of R. microplus, suggesting the vertical transmission of these two pathogens in R. microplus. Our findings provide important information regarding the distribution and ecology of these tick-borne rickettsiae. [ABSTRACT FROM AUTHOR]

Toxoplasma gondii (T. gondii) is a zoonotic parasite that can cause serious pathology in intermediate hosts such as humans and animals. Eating undercooked or raw meat is the most important route of infection by T. gondii. Sheep are an important source of meat worldwide, and they are also susceptible to T. gondii. Mutton infected with T. gondii poses a serious threat to the food safety of consumers. At present, studies have mainly focused on the infection ratio of T. gondii in livestock; however, systematic studies have not been performed on differences in the distribution of this parasite in different muscle and viscera tissues of animals. In this study, the differences in the distribution of T. gondii in naturally infected Small-tailed Han sheep was studied. By amplifying the B1 gene of the parasite via real-time fluorescence quantification PCR (RT‒qPCR), we found that the parasite burden of T. gondii differed among different parts of the sheep, with the highest burden observed in the heart among the viscera and the external ridge among the muscle. The relative expression was ranked from high to low in our study as follows: heart, spleen, external ridge, tenderloin, lung, liver, kidney, neck meat, forelegs, cucumber strips, hind leg, lamb belly, and lamb chops. This study provided important guidance for monitoring the food safety of mutton products. [ABSTRACT FROM AUTHOR]

The field and microstructural features coupled with mineral chemical data from microgranular enclave (ME) and host Mesoproterozoic Kanigiri granite (KG) pluton of Nellore Schist Belt (NSB), Southeastern India, have been documented in order to infer the likely processes responsible for the origin and evolution of ME and host KG magma. The ME and host KG bear the same mineral assemblages barring the KG which does not contain amphibole; however, they are modally disequilibrated. The ME in KG is originated due to multiple intrusions of ME magmas into the crystallizing host KG magma chamber. Field and textural features indicate the dynamic magma flow, mingling, and undercooling of the ME against a relatively cooler surface of host KG magma. The presence of NSB country rock xenoliths and its diffuse boundaries suggest the intrusive relation and marginal assimilation by the intruding KG magma. The occasional cumulate texture in the ME appears to have formed by the accumulation of early-formed minerals that crystallized rapidly in the ME magma globules. The ME shows the magmatically deform features developed due to the flowage and erosion by the subsequent intrusions of ME magma pulses into the crystallizing host KG magma chamber. The ME amphiboles show unusual composition as ferro-edenitic hornblende to potassian-hastingsitic hornblende, that crystallized in the subalkaline-alkaline transition, low fO2(reducing to mildly oxidizing) magma. The unusual extremely low Mg/Mg + Fet = 0.015 (avg.) of ME amphiboles may be related to the changing physico-chemical (P, T, fO2, and H2O) condition of the ME magma or they might have crystallized in equilibrium with more evolved KG magma. The KG (FeOt/MgO = 37.04, avg.) and ME (FeOt/MgO = 77.72, avg.) biotites are siderophyllite, and buffered between QFM and NNO syn-crystallizing in the water undersaturated (H2O ≈ 3.58 wt.% in KG; ≈3.53wt.% in ME), alkaline anorogenic (A-type) host magmas that were emplaced at mid-crustal (4–5 kbar; ~ 17 km) depth. Field, microtextural and mineral chemical evidences suggest that the alkaline KG magma originated from crustal source and evolved through synchronous fractionation, mixing, and mingling with coeval ME magmas in the KG magma chamber. [ABSTRACT FROM AUTHOR]

Background: The indigenous populations of Brazil present poor health indicators and a disproportionate prevalence and case-fatality rate of neglected tropical diseases, including snakebite envenomations (SBEs). This study aims to estimate access to medical care for SBEs and analyze the barriers that prevent victims from accessing healthcare in indigenous communities in two health districts located in the Western Brazilian Amazon. Methodology/Principal findings: This cross-sectional study used semi-structured interviews to collect data from individuals who experienced SBEs in the Upper Rio Solimões and Upper Rio Negro indigenous health districts. Of the 187 participants, 164 (87.7%) reported that they had access to healthcare and received assistance in a hospital in the urban area of the municipalities. Frequency was 95.4% in the Upper Rio Solimões SIHD, and 69.6% in the Upper Rio Negro SIHD (P<0.0001). The study found that the availability of indigenous medicine as the only choice in the village was the main reason for not accessing healthcare (75%), followed by a lack of financial resources and means of transportation (28.1%). Four deaths were reported from SBEs, resulting in a case-fatality rate of 2.1%. Conclusions/Significance: In the study areas, there are records of SBE patients who did not receive medical attention. Availability of pre-hospital emergency transport using motorboats, a greater number of hospitals and better navigability of the Solimões River and its tributaries would make access easier for indigenous people living in the region of the Upper Solimões River. The implementation of cross-cultural hospital care needs to be considered in order to reduce the resistance of indigenous populations in relation to seeking treatment for SBEs. Author summary: Interdisciplinary research on snakebites and the engagement of indigenous and riverine populations of the Amazon are essential for the formulation of innovative and tailored strategies towards achieving the global target of halving the number of deaths and disabilities due to snakebite envenomations by 2030 in Brazil. These populations are key to reducing these poor outcomes since they are disproportionately affected by snakebites. In this work, we evaluated access to medical care in SBE patients and analyzed barriers that prevent victims from accessing healthcare in indigenous villages in two health districts in the Brazilian Amazon. Snakebites were reported in all age groups, including a high rate among children, which demonstrates their great contact with venomous snakes in indigenous villages. A proportion of 12.3% of individuals with a lifetime history of snakebites did not receive hospital treatment, ranging from 4.6% in the Upper Rio Solimões health district to 30.4% in the Upper Rio Negro health district. Availability of pre-hospital emergency transport using motorboats, a greater number of hospitals and better navigability of the Solimões River and its tributaries would make access easier for indigenous people living in this district. We discuss the role that the implementation of cross-cultural hospital care, which considers specific indigenous needs for accommodation and food, may have in reducing the resistance of indigenous populations to seek western treatment for snakebites. [ABSTRACT FROM AUTHOR]

The growing proximity of wildlife to large urban niches arouses greater interest in understanding wild reservoirs in the epidemiology of diseases of importance to animal and human health. The aim of the present study was to investigate the presence of piroplasmids in opossums rescued from the metropolitan region of Rio de Janeiro state, Brazil. Blood and bone marrow samples were collected from 15 Didelphis aurita and subjected to DNA extraction and PCR using primers for the 18S rRNA, cox1, cox3, and hsp70 genes of piroplasmids. Clinical and hematological evaluation of the animals was also performed. Five (33.3%) of the 15 opossums tested positive for piroplasms in the nested PCR based on the 18S rRNA, and in two animals, it was possible to observe intra-erythrocytic structures compatible with merozoites. One of the positive animals showed clinical signs of infection such as jaundice, fever, and apathy. Anemia, low level of plasma protein, leukocytosis, and regenerative erythrocyte signs were observed in positive animals. Phylogenetic analysis based on both 18S rRNA and cox-3 genes demonstrated that the piroplasmids detected in D. aurita formed a unique sub-clade, albeit related to piroplasmids previously detected in Didelphis albiventris and associated ticks from Brazil. This study proposes the novel Piroplasmida Clade, namely "South American Marsupialia Group," and reinforces the need for new clinical-epidemiological surveys to understand the dynamics of these infections in didelphids in Brazil. [ABSTRACT FROM AUTHOR]

Animal ectoparasites are linked to the spread of serious medical and veterinary important pathogens. Our research intends to close the knowledge gap concerning the numerous ectoparasites that inhabit animals in Wayanad. Ectoparasites in animals brought to the veterinary dispensaries in Wayanad were retrieved and identified morphologically and molecularly. Using a high-quality stereomicroscope, the taxonomic features of the four following species were examined and identified: Haemaphysalis bispinosa, Rhipicephalus annulatus, R. microplus, and Amblyomma geoemydae. The important disease vector A. geoemydae was reported for the first time in Kerala. The important phenotypic characters of the highlighted species A. geoemydae are the edge of the basis capituli is circular without cornua, and the hypostomal dental formula is 2/2. The taxonomically identified four species were subjected to CO1 gene sequence analysis. The evolutionary relationship was inspected through the neighbour-joining method, and the phylogenetic tree was built through the Maximum Likelihood method. The present study has also estimated the diversity index of R. microplus, R. annulatus, H. bispinosa, and A. geoemydae. Among them, R. microplus 0.36638 have reported with the maximum diversity index score. The significance of the study is the presence of Lyme disease vector A. geoemydae, in the Wayanad District of Kerala, and it is the first report of the species from where an outbreak of Lyme disease occurred in 2013. [ABSTRACT FROM AUTHOR]

Procyonids are reservoirs of many zoonotic infectious diseases, including tick-borne pathogens. The role of coatis (Nasua nasua) in the epidemiology of piroplasmids and Rickettsia has not been fully addressed in Brazil. To molecularly study these agents in coatis and associated ticks, animals were sampled in two urban areas in Midwestern Brazil. Blood (n = 163) and tick (n = 248) DNA samples were screened by PCR assays targeting the 18S rRNA and gltA genes of piroplasmids and Rickettsia spp., respectively. Positive samples were further molecularly tested targeting cox-1, cox-3, β-tubulin, cytB, and hsp70 (piroplasmid) and ompA, ompB, and htrA 17-kDa (Rickettsia spp.) genes, sequenced and phylogenetically analyzed. All coatis' blood samples were negative for piroplasmids, whereas five pools of ticks (2%) were positive for two different sequences of Babesia spp.. The first from Amblyomma sculptum nymphs was close (i.e., ≥ 99% nucleotide identity) to a Babesia sp. previously found in capybaras (Hydrochoerus hydrochaeris); the second from Amblyomma dubitatum nymphs and Amblyomma spp. larvae was identical (100% nucleotide identity) to a Babesia sp. detected in opossums (Didelphis albiventris) and associated ticks. Four samples (0.8%) were positive by PCR to two different Rickettsia spp. sequences, being the first from Amblyomma sp. larva identical to Rickettsia belli and the second from A. dubitatum nymph identical to Rickettsia species from Spotted Fever Group (SFG). The detection of piroplasmids and SFG Rickettsia sp. highlights the importance of Amblyomma spp. in the maintenance of tick-borne agents in urban parks where humans and wild and domestic animals are living in sympatry. [ABSTRACT FROM AUTHOR]

Tapirs are common hosts of ticks and an individual can be infested by up to seven different tick species. We explored the parasitic tick fauna associated with wild Baird's tapirs (Tapirus bairdii) from the Yucatan Peninsula. A total of 326 ticks of 10 species of the Family Ixodidae were collected from 15 tapirs. We found a range of one to six tick species per host, but most of the tapirs were parasitized by two or three tick species. We tested the relationship between body condition, sex, and age classes of the tapirs versus the number of tick species on each host. The most common tick species was Amblyomma mixtum found on 93% of the hosts. Amblyomma pecarium, Amblyomma tenellum, Ixodes affinis and Rhipicephalus sanguineus sensu lato were recorded for the first-time parasitizing Baird's tapirs. We did not find a relationship between body condition, sex, and age classes of tapirs versus the number of parasitizing tick species. Our finding demonstrates that the richness of ticks parasitizing tapirs does not depend on the biological characteristics and health status of the host, but could be determined by other factors such as habitat use and the rate of contact with domestic animals. [ABSTRACT FROM AUTHOR]

Background: The tick Amblyomma sculptum is the major vector of Rickettsia rickettsii, the causative agent of the highly lethal Brazilian spotted fever. It has been shown that R. rickettsii inhibits apoptosis in both human endothelial cells and tick cells. Apoptosis is regulated by different factors, among which inhibitors of apoptosis proteins (IAPs) play a central role. In the study reported here, we selected an IAP of A. sculptum that has not yet been characterized to assess its role in cell death and to determine the effects of its gene silencing on tick fitness and R. rickettsii infection. Methods: An A. sculptum cell line (IBU/ASE-16) was treated with specific double-stranded RNA (dsRNA) for either IAP (dsIAP) or green fluorescent protein (dsGFP; as a control). The activity of caspase-3 and the exposure of phosphatidylserine were determined in both groups. In addition, unfed adult ticks, infected or not infected with R. rickettsii, were treated with either dsIAP or dsGFP and allowed to feed on noninfected rabbits. In parallel, noninfected ticks were allowed to feed on an R. rickettsii-infected rabbit. Ticks (infected or not with R. rickettsii) that remained unfed were used as a control. Results: Caspase-3 activity and the externalization of phosphatidylserine were significantly higher in IBU/ASE-16 cells treated with dsIAP than in those treated with dsGFP. The mortality rates of ticks in the dsIAP group were much higher than those in the dsGFP group when they were allowed to feed on rabbits, independent of the presence of R. rickettsii. Conversely, lower mortality rates were recorded in unfed ticks. Conclusions: Our results show that IAP negatively regulates apoptosis in A. sculptum cells. Moreover, IAP-silenced ticks experienced higher mortality rates following the acquisition of a blood meal, suggesting that feeding may trigger the activation of apoptosis in the absence of this physiological regulator. These findings indicate that IAP is a potential antigen for an anti-tick vaccine. [ABSTRACT FROM AUTHOR]

The ecology of chigger mites has many unknown aspects, even with several recent studies addressing the taxonomy and systematics of this group. In Brazil, the chigger species recorded coparasitizing vertebrates include opossums in the Pernambuco State, lizards and rodents in the Piauí State, and rodents in the São Paulo State. Chiggers collected on a domestic cat, Felis catus Linnaeus, 1758 (Mammalia: Felidae), from Caxias do Sul, Rio Grande do Sul State, were sent to the Acarological Collection of Instituto Butantan (IBSP) to be identified. The species were identified as eight larvae of Eutrombicula tinami, two larvae of Parasecia valida Brennan, 1969, and two specimens of the genus Eutrombicula Ewing, 1938, which have been described here as Eutrombicula bassiniin. sp. Additionally, we amplified partial 18S rRNA gene sequences for E. tinami and E. bassiniin. sp. However, the attempts to amplify fragments of the gltA gene of Rickettsia were unsuccessful. The present study reports the coparasitism in a domesticated feline with these three species, the second record of E. tinami, the first record P. valida to the Rio Grande do Sul State, and the description of E. bassiniin. sp. [ABSTRACT FROM AUTHOR]

Transovarial transmission (TOT) is an efficient vertical transmission of pathogens that is observed in many arthropod vectors. This method seems to be an evolutionarily unique development observed only in Babesia sensu stricto (clade VI) and Rickettsia spp., whereas transstadial transmission is the common/default way of transmission. Transovarial transmission does not necessarily contribute to the amplification of tick-borne pathogens but does contribute to the maintenance of disease in the environment. This review aims to provide an updated summary of previous reports on TOT of tick-borne pathogens. [ABSTRACT FROM AUTHOR]

Visceral leishmaniasis (VL) is the second most common protozoosis that affects people around the world. The aim of this study is to understand how environmental and socioeconomic factors, as well as VL control and surveillance interventions, influence the spread and detection of VL cases in Pernambuco state (Brazil). A novel model was developed to analyze cases of VL between 2007 and 2018, enabling the quantification of the association of these variables with two processes: the probability of "invasion" (emergence of new cases) at municipalities by VL, and the probability of detecting cases not reported in municipalities that have already been invaded. Pernambuco state identified 1,410 cases of VL between 2007 and 2018, with an average of 128 cases per year and average incidence of 1.28/100 thousand people. These cases were distributed in 77.1% (142/184) of the municipalities, and 54.8% (773/1,410) of them were autochthonous. Our model reveals that the proportion of agriculture was positively associated with VL invasion probability. We also find that municipalities that are closer to notification centers and/or that have received technical training and support tend to have higher detection rates of VL cases. Taken together, these results suggest that a municipality with almost no agriculture and that received technical training, located close to a notification center, is unlikely to be invaded if no cases have ever been detected. On the other hand, a municipality that is far from the notification center, with no technical training, with a large agricultural area might have already been invaded but the surveillance system might have routinely failed to detect VL cases due to low detection probability. By disentangling the processes of invasion and detection, we were able to generate insights that are likely to be useful for the strategic allocation of VL prevention and control interventions. Author summary: Visceral leishmaniasis (VL) is an important neglected zoonosis around the world. We evaluated how environmental and socioeconomic factors, as well as VL control and surveillance interventions, influence the spread and detection of VL cases in Pernambuco state (Brazil), which is endemic. Our results reveal that municipalities with almost no agriculture that received technical training and are located close to a notification center are unlikely to have VL infected individuals if no cases have ever been detected. On the other hand, a municipality distant from the notification center, with no technical training, and with a large agricultural area might have already had unreported cases. These results can serve as a foundation to improve the personnel training and notification system strategies adopted by VL Public Health Programs. [ABSTRACT FROM AUTHOR]

Background: Deer species play an important role in the enzootic cycles of several Anaplasma species. While in the Northern Hemisphere ticks of genus Ixodes are well recognized vectors of these intracellular bacteria, less is known regarding the biological cycles of Anaplasma spp. in South America. Methods: Using PCR protocols and Sanger sequencing, we assessed the presence of Anaplasma spp. in blood and ticks collected on a native deer species (Pudupuda) from southern Chile. Results: Based on phylogenetic analyses of the 16S rRNA, gltA and groEL genes and calculation of average sequence divergence for groEL, our results bring to light a novel genovariant of Anaplasmaphagocytophilum (named strain "Patagonia"). The strain represents a novel ecotype within the A. phagocytophilum species complex and was detected in both P.puda and their ticks. Using a larger matrix, denser taxon sampling and outgroup, our maximum-likelihood- and Bayesian-inferred phylogenies for groEL provide an accurate picture of the topology of A. phagocytophilum ecotypes and their evolutionary relationships. Conclusions: This is the first report of an ecotype of A. phagocytophilum in South America. Our results provide novel insight into the genetic diversity and ecology of this complex of bacterial lineages. Further studies should elucidate the enzootic cycle of A. phagocytophilum strain "Patagonia" and assess its pathogenic potential for pudues, domestic animals and humans in the region. [ABSTRACT FROM AUTHOR]

Reptiles, as well as other vertebrate groups, harbour a significant diversity of parasitic organisms, from nematodes and other helminths to viruses and bacteria. The Northeast is one of the richest regions in Brazil in terms of the reptile diversity, number of species and endemism. Parasites are diverse organisms and knowledge about the parasitic fauna of vertebrates is an important factor in understanding the ecological relationships between hosts and the environment. Studies on the parasitic fauna of reptiles in South America have increased in the past few years. The present review is a compilation of 122 studies published from 1924 to 2021. We present information on 101 species of reptiles from five groups (amphisbaenians, crocodile, testudines, snakes and lizards) and 183 parasitic taxa belonging to four phyla: Nematoda; Arthropoda; Platyhelminthes; and Acanthocephala. Nematodes were the most frequently recorded species. Lizards and snakes had more records of parasitism and higher levels of parasite richness and diversity. Ceará was the state with most studies and recorded cases of parasite–host association. The Caatinga and Atlantic Forest were the most investigated environments. The objective of this review was to contribute knowledge on the parasitic biodiversity in reptiles from Northeast Brazil, which may help identify gaps in our knowledge and guide future studies. [ABSTRACT FROM AUTHOR]

Background: Ticks act as important vectors of infectious agents, and several emerging tick-borne viruses have recently been identified to be associated with human diseases in northeastern China. However, little is known about the tick virome in northeastern China. Methods: Ticks collected from April 2020 to July 2021 were pooled for metagenomic analysis to investigate the virome diversity in northeastern China. Results: In total, 22 RNA viruses were identified, including four each in the Nairoviridae and Phenuiviridae families, three each in the Flaviviridae, Rhabdoviridae, and Solemoviridae families, two in the Chuviridae family, and one each in the Partitiviridae, Tombusviridae families and an unclassified virus. Of these, eight viruses were of novel species, belonging to the Nairoviridae (Ji'an nairovirus and Yichun nairovirus), Phenuiviridae (Mudanjiang phlebovirus), Rhabdoviridae (Tahe rhabdovirus 1–3), Chuviridae (Yichun mivirus), and Tombusviridae (Yichun tombus-like virus) families, and five members were established human pathogens, including Alongshan virus, tick-borne encephalitis virus, Songling virus, Beiji nairovirus, and Nuomin virus. I. persulcatus ticks had significant higher number of viral species than H. japonica, H. concinna, and D. silvarum ticks. Significant differences in tick viromes were observed among Daxing'an, Xiaoxing'an and Changbai mountains. Conclusions: These findings showed an extensive diversity of RNA viruses in ticks in northeastern China, revealing potential public health threats from the emerging tick-borne viruses. Further studies are needed to explain the natural circulation and pathogenicity of these viruses. Author summary: Ticks are important vectors to transmit many infectious agents. In recent years, many novel tick-borne viruses associated with human illness, including Alongshan virus, Songling virus, and Beiji nairovirus, have been identified in northeastern China. It is necessary to conduct routine surveillance of tick-borne viruses in ticks, however, little is known about the tick virome in northeastern China. In this study, we used metatranscriptomics to investigate the virome diversity in four tick species collected from northeastern China. In total, we identified 22 RNA viruses belonging to eight virus families (exclude an unclassified virus). Of these, five members were established human pathogens, eight viruses were of novel species, and six viruses had close relationship with pathogenic tick-borne viruses with potential public health threats. Moreover, we found that the viromes were significantly affected by the tick species and geographical location in the study. These findings revealed an extensive diversity of RNA viruses in ticks in northeastern China, which will lay the foundation for the prevention and control of emerging tick-borne diseases. [ABSTRACT FROM AUTHOR]

Summary: Liquid phase sintering (LPS), by the addition of transition metal additives, has become one of the most preferred approaches to lower the sintering temperature of yttrium‐doped barium zirconate (BZY) proton‐conducting ceramics. Nonetheless, this approach is known to negatively impact the bulk conductivity of the parent perovskite phase, due to the significant incorporation of the sintering additive into the bulk composition. In the current work, we study the typical proton conducting material BaZr0.8Y0.2O3−δ (BZY20), prepared by One or Two‐step sintering strategies using 4 mol% NiO of sintering additive, compared against a control sample of pure BZY20. The main results demonstrate that the Two‐step approach is shown to minimise Ni interreaction with the BZY material, allowing this sample to maintain a higher hydration capacity than the One‐step material, as confirmed by X‐ray diffraction (XRD), scanning transmission electron microscopy/energy‐dispersive spectrocopy (STEM/EDS) and thermogravimetric (TG) measurements. Despite these benefits, the Two‐step approach presents a diminished bulk conductivity, which was ascribed to depletions in proton mobility due to "proton trapping" effects. In addition, the specific grain boundary conductivity was revealed to be higher in the Two‐step sample, as a possible result of a higher Ni accumulation in this region. Overall, this work opens an exciting new debate for further studies, in that prevention of Ni‐incorporation in the bulk material, as typically suggested in current literature, may not actually be the best method to improve the conductivity of samples densified by Ni‐additives and that control of potential defect associations may be the more critical method for conductivity tailoring. [ABSTRACT FROM AUTHOR]

Three studies on the biology of Ornithodoros puertoricensis are available in the literature, using different hosts and incubation temperatures. In a previous study, we identified O. puertoricensis in the Colombian Caribbean. The aim of the present work was to analyze life cycle data along one generation from these specimens under laboratory conditions. Eggs of O. puertoricensis were collected in between fragments of bahareque material in a rural dwelling in the municipality of Planeta Rica (Córdoba Department, Colombia), and transported to the laboratory. All post-egg stages (i.e., larvae, nymphs, and adults) were incubated at 27 °C and 85% RH and fed on laboratory mice (Mus musculus). Sixteen engorged larvae were obtained to start a laboratory colony. Average feeding period for larvae was 4.6 days (4–5). The first nymphal instar (N1) did not require feeding and the subsequent nymphal stages (N2, N3, and N4) and adults had feeding periods ranging from 55 to 75 min. Average pre-molting period in nymphs was 15 days (10–21). Most of the N3 molted to males and all N4 molted to females. Two gonotrophic cycles were recorded: the first had a preoviposition period of 12 days (7–18) and produced 190 eggs (171–223), the second lasted 6.6 days (6–7) and produced 146 eggs (104–201). The mean life cycle duration (from parental eggs to F1 eggs) was 70.7 days (58.7–82.7) without fasting periods. The collected data agree with previous studies even with differences in hosts and maintenance conditions. [ABSTRACT FROM AUTHOR]

From June 2013 to January 2014, blood sera samples and ticks were collected from domestic dogs and wild small mammals, and ticks from the vegetation in a preservation area of the Atlantic Forest biome (Turvo State Park), and the rural area surrounding the Park in Derrubadas municipality, state of Rio Grande do Sul, southern Brazil. Dogs were infested by Amblyomma ovale and Amblyomma aureolatum adult ticks, whereas small mammals were infested by immature stages of A. ovale, Amblyomma yucumense, Amblyomma brasiliense, Ixodes loricatus, and adults of I. loricatus. Ticks collected on vegetation were A. brasiliense, A. ovale, A. yucumense, Amblyomma incisum, and Haemaphysalis juxtakochi. Three Rickettsia species were molecularly detected in ticks: Rickettsia bellii in I. loricatus (also isolated through cell culture inoculation), Rickettsia amblyommatis in A. brasiliense, and Rickettsia rhipicephali in A. yucumense. The latter two are tick-rickettsia associations reported for the first time. Seroreactivity to Rickettsia antigens were detected in 33.5% (55/164) small mammals and 8.3% (3/36) canine sera. The present study reveals a richness of ticks and associated-rickettsiae in the largest Atlantic Forest Reserve of the state of Rio Grande do Sul, which is characterized by a rich fauna of wild mammals, typical of more preserved areas of this biome. Noteworthy, none of the detected Rickettsia species have been associated to human or animal diseases. This result contrasts to other areas of this biome in Brazil, which are endemic for tick-borne spotted fever caused by Rickettsia rickettsii or Rickettsia parkeri. [ABSTRACT FROM AUTHOR]

From a previous large epidemiological survey, we randomly selected 474 serum samples (463 horses and 11 mules) distributed among four municipalities of Pará state, Amazon region, Brazil, and from three types: farm animal, urban carthorse, and sport horse. Samples were tested by indirect fluorescence antibody test (IFAT ≥ 64) for antibodies reactive to spotted fever group (SFG) rickettsiae using Rickettsia rickettsii as crude antigens. From the 474 equids tested, 149 (31.4%) had ticks attached during sampling, belonging mostly to the species Dermacentor nitens. The overall seroprevalence for SFG rickettsiae was 31.4% (95% confidence interval: 27.3–35.9%) with 149 seropositive animals out of 474 screened. Notably, 77 equids (16.2%) had high endpoint titers ranging from 512 to 16,384, indicating that they had been exposed to SFG rickettsiae not long before sampling. Animal type affected rickettsial seroprevalence, with significantly higher values among farm horses when compared with urban and sport animals. Presence of dogs and tick infestation were negatively associated with equid seropositivity to R. rickettsii. This is the first report of SFG rickettsiae-reactive antibodies in equids from Pará state, Brazilian Amazon. [ABSTRACT FROM AUTHOR]

Leishmania infections span a range of clinical syndromes and impact humans from many geographic foci, but primarily the world's poorest regions. Transmitted by the bite of a female sand fly, Leishmania infections are increasing with human movement (due to international travel and war) as well as with shifts in vector habitat (due to climate change). Accurate diagnosis of the 20 or so species of Leishmania that infect humans can lead to the successful treatment of infections and, importantly, their prevention through modelling and intervention programs. A multitude of laboratory techniques for the detection of Leishmania have been developed over the past few decades, and although many have drawbacks, several of them show promise, particularly molecular methods like polymerase chain reaction. This review provides an overview of the methods available to diagnostic laboratories, from traditional techniques to the now-preferred molecular techniques, with an emphasis on polymerase chain reaction-based detection and typing methods. [ABSTRACT FROM AUTHOR]

Toxocariasis is a paramount parasitic disease having > 50% prevalence among newborn buffalo calves in Bangladesh. The objective of this study was to compare the efficacy of clinically used anthelmintics and their subsequent effect on the haematological parameters and body weight in buffalo calves in commercial buffalo farms in coastal region. Thirty-two buffalo calves below 3 months of age with clinical Toxocara infection had been selected and treated with albendazole (ABZ), levamisole (LVM) and ivermectin (IVM). The EPG counts, hematological parameters and initial body weight of buffalo calves were recorded on the day of anthelmintic treatment (day 0). Fecal samples were collected on day 14 and 28 including hematological parameters and body weight were recorded on day 28 post-treatment. The efficacy (%) of anthelmintics were estimated by fecal egg count reduction test (FECRT). The parameters like Hb, PCV, ESR, TEC, TLC were analyzed from the blood samples. The FECRT revealed 96.83% efficacy for IVM followed by 94.23% and 85.84% for LVM and ABZ, respectively. Anthelmintic treated calves showed significant (p < 0.01) increase in Hb, PCV, TEC and body weight, and decrease in ESR and TLC as a result of worm expulsion from buffalo calves after 28 days of post-treatment. Among the tested anthelmintics, IVM was found to be more effective against toxocariasis in buffalo calves. This is a novel information on anthelmintics efficacy in buffalo calves in Bangladesh. Details study is recommended on the efficacy of anthelmintics in different buffalo management systems by in vitro egg hatch assay (EHA) test. [ABSTRACT FROM AUTHOR]

Leishmania infections span a range of clinical syndromes and impact humans from many geographic foci, but primarily the world's poorest regions. Transmitted by the bite of a female sand fly, Leishmania infections are increasing with human movement (due to international travel and war) as well as with shifts in vector habitat (due to climate change). Accurate diagnosis of the 20 or so species of Leishmania that infect humans can lead to the successful treatment of infections and, importantly, their prevention through modelling and intervention programs. A multitude of laboratory techniques for the detection of Leishmania have been developed over the past few decades, and although many have drawbacks, several of them show promise, particularly molecular methods like polymerase chain reaction. This review provides an overview of the methods available to diagnostic laboratories, from traditional techniques to the now-preferred molecular techniques, with an emphasis on polymerase chain reaction-based detection and typing methods. [ABSTRACT FROM AUTHOR]

Toxoplasma gondii causes severe disease in congenitally infected fetuses. The severity of fetal infection is related to the gestational stage at the time of maternal infection, parasite burden, and genotypic characteristics. South America has a high incidence of congenital toxoplasmosis and has the highest genotypic diversity of the parasite. In Brazil, clinical toxoplasmosis in children is notorious, however there are very limited data regarding the strains recovered from congenital infections. In this study, T. gondii strains from two cases of severe congenital toxoplasmosis from the São Paulo metropolitan area were isolated (TgHumIMTBr2 and TgHumIMTBr3) and biologically and molecularly characterized using polymerase chain reaction-restriction fragment length polymorphism (PCR–RFLP) and microsatellite analysis, revealing a new non-archetypal virulent genotype designated as #318. The other isolate, genotype #175, has already been described in domestic and wild animals in Brazil, but is now associated with acute toxoplasmosis in humans. These data reinforce the role of non-archetypal T. gondii genotypes in the severity of human congenital toxoplasmosis, highlighting the importance of studies focused on parasite isolation and genotyping for a better understanding of the virulence of isolates from human toxoplasmosis and contributing to the knowledge of the diversity of T. gondii in Brazil. [ABSTRACT FROM AUTHOR]

Toxoplasmosis is an important zoonotic disease that affects a wide range of warm-blooded host species. Neotropical primates (New World Primates; NWP) are highly susceptible, developing a lethal acute systemic disease. Toxoplasmosis in free-ranging NWP is poorly described, with only a few studies based on serosurveys. Herein we performed a retrospective study focusing on the epidemiology and pathology of toxoplasmosis among 1,001 free-ranging marmoset (Callithrix spp.) deaths from the Brazilian Atlantic Forest. This study included marmosets necropsied at the Instituto Municipal de Medicina Veterinária Jorge Vaitsman (IJV) from January 2017 to July 2019, which were found dead from all regions in the State of Rio de Janeiro. Histopathology, immunohistochemistry, and transmission electron microscopy were performed to better characterize toxoplasmosis in this free-ranging population. All samples were also tested for Yellow Fever Virus (YFV) RT-qPCR by the official diagnostic service. A total of 1,001 free-ranging marmosets were included in this study, with 16 (1.6%) cases of lethal Toxoplasma gondii infections identified both as individual cases and in outbreaks. Presence of infection was not associated with sex, age, geographical distribution, or year of death, and no co-infection with YFV was observed. The main pathological feature in these cases was random necrotizing hepatitis with detection of intralesional T. gondii zoites in all infected cases. Interstitial pneumonia rich in alveolar foamy macrophages and fibrin deposition, necrotizing myocarditis and necrotizing splenitis were also pathological features in affected marmosets. Therefore, toxoplasmosis was considered the cause of death in 1.6% of free-ranging marmosets in this retrospective series, including some cases associated with outbreaks. Necrotizing random hepatitis was a consistent pathological finding in affected cases and sampling of liver should be ensured from Callitrichid post mortem cases. Author summary: Toxoplasmosis is an important zoonotic disease that represents a concern to captive neotropical primates, due to its high susceptibility, with quick lethal course. Large studies of the pathology and epidemiology of toxoplasmosis in in wildlife neotropical primates are rare, rendering it difficult to evaluate the impact of this disease in free-ranging population. This study investigated toxoplasmosis-induced deaths in 1,001 free-ranging marmosets, describing its epidemiology, pathology, and diagnostic tools. Also, this study highlights the importance of histopathology in the differential diagnosis of other important zoonotic diseases that may circulate in that population, such as Yellow Fever. [ABSTRACT FROM AUTHOR]

Rickettsiosis is considered an emerging/re-emerging vector-borne disease that causes significant public health threats. Ticks are reservoirs and vectors of Rickettsia having a significant role in the transmission of rickettsiae. In Portugal, little is known about tick-borne Rickettsia species in sheep. Therefore, this study aimed to investigate rickettsiae infection in ticks and their sheep host from 27 farms in four districts of central Portugal, to clarify the role of the sheep host in the circulation of this zoonotic agent. Between March and May 2021, EDTA blood samples (n = 100) of healthy grazing sheep and their ticks (n = 100, one tick per animal) were collected during a herd health program in central Portugal. Obtained ticks were identified as Rhipicephalus sanguineus sensu lato by PCR targeting a partial sequence of 16S rRNA gene followed by sequence analysis. Rhipicephalus sanguineus s.l. and host sheep blood were tested for the presence of Rickettsia spp. by PCR targeting a partial sequence of ompB and ompA genes. From a total of 100 paired R. sanguineus s.l. and host sheep, Rickettsia massiliae was detected in 62 ticks and 35 grazing sheep blood samples, collected in central Portugal, 2021. All 35 positive sheep had attached positive R. sanguineus s.l., with matching nucleotidic sequences. These findings suggest that sheep may develop rickettsiemia and are likely capable of transmitting and amplifying the infection to uninfected ticks maintaining rickettsiae in circulation in the domestic cycle. [ABSTRACT FROM AUTHOR]

Toxoplasmosis, an infection caused by Toxoplasma gondii, is widely distributed. Seroprevalence in pets is a reliable tool to determine environmental parasite presence and human risk of infection due to proximity to these animals. The frequency of anti-T. gondii IgG antibodies in sera of dogs and cats from Espírito Santo, Brazil and risk factors associated with the infection (sex, age, allocation, and breed) were assessed. Antibodies against T. gondii were detected in 39.4% (149/378) and 38.1% (142/373) of the dogs by enzyme-linked immunosorbent assay (ELISA) and by indirect immunofluorescence antibody test (IFAT), respectively. In cats, antibodies were detected in 15.2% (12/79) by ELISA and 7.6% (6/79) by IFAT. Canine infection was associated with stray origin and older ages. There was an agreement between techniques in the detection of antibodies in dogs (... 0.82) and cats (... 0.63). These results indicate the parasite presence in the urban environment, suggesting the possibility of infection to humans and other animals. However, this risk is lower considering pet domiciled animals with control diet and better hygiene conditions. [ABSTRACT FROM AUTHOR]

Domestic dogs (Canis lupus familiaris) can transmit a variety of pathogens due to their ubiquitousness in urban, rural and natural environments, and their close interactions with wildlife and humans. In this study, we used a mixed-methods approach to assess the role of domestic dogs as potential intermediaries of disease transmission from wildlife to humans among indigenous Waiwai in the Konashen Community Owned Conservation Area, Guyana. To address these objectives we 1) performed physical examinations and collected biological samples to assess Waiwai domestic dog health, and 2) administered questionnaires to characterize the role of dogs in the community and identify potential transmission pathways between wildlife, dogs, and humans. We observed ectoparasites on all dogs (n = 20), including: fleas (100%), ticks (15%), botflies (30%), and jigger flea lesions (Tunga penetrans) (80%). Ten percent of dogs were seropositive for Ehrlichia canis/ewingii, 10% were positive for Dirofilaria immitis, and one dog was seropositive for Leishmania infantum. All dogs (n = 20) were seronegative for: canine distemper virus, Brucella canis, Leptospira serovars, Trypanosoma cruzi, Anaplasma phagocytophilum/platys and Borrelia burgdorferi. Our questionnaire data revealed that the Waiwai remove ectoparasites from their dogs, clean up dog feces, and administer traditional and/or Western medicine to their dogs. White blood cell, strongyle-type ova, and eosinophil counts were lower in dogs that were not frequently used for hunting, dogs that did receive traditional and/or western medicine, and dogs that were frequently kept in elevated dog houses, although differences were not statistically significant. While our results suggest that the Waiwai have developed cultural practices that may promote dog health and/or prevent zoonotic disease transmission, more research is necessary to determine the efficacy of these practices. Our study provides important data on the health of dogs and the potential for disease transmission to humans in a zoonotic hotspot. Author summary: Domestic dogs are found throughout the world and interact closely with both wildlife and humans. Dogs can harbor numerous diseases that can be transmitted to other domestic and wildlife species, and human populations. They can serve as bridges, moving diseases between unconnected populations. Additionally, dogs can help in the early detection of wildlife and human diseases. Therefore, understanding what pathogens domestic dogs harbor can inform both wildlife and human health. In this study, we performed physical examinations, collected biological samples, and administered questionnaires to assess dog health and understand the role of dogs as potential bridges of disease transmission from wildlife to humans among indigenous Waiwai in the Konashen Community Owned Conservation Area, Guyana. On physical exam, we observed ectoparasites on all dogs, however, few pathogens were detected with diagnostic screening. Our questionnaire data revealed that the Waiwai engage in husbandry practices that may promote Waiwai dog health. [ABSTRACT FROM AUTHOR]

Relapsing fever group Borrelia (RFGB) are motile spirochetes transmitted to mammalian or avian hosts through the bite of hematophagous arthropods, such as soft ticks (Argasidae), hard ticks (Ixodidae) and the human clothing lice. RFGB can infect pets such as dogs and cats, as well as birds, cattle and humans. Borrelia recurrentis, B. anserina and B. theileri are considered to have worldwide distribution, affecting humans, domestic birds and ruminants, respectively. Borrelia spp. associated with soft ticks are transmitted mainly by Ornithodoros ticks and thrive in endemic foci in tropical and subtropical latitudes. Nowadays, human cases of soft tick-borne relapsing fever remain neglected diseases in several countries, and the impact these spirochetes have on the health of wild and domestic animals is largely understudied. Human infection with RFGB is difficult to diagnose, given the lack of distinguishing clinical features (undifferentiated febrile illness). Clinically, soft tick or louse-borne relapsing fever is often confused with other etiologies, such as malaria, typhoid or dengue. In Latin America, during the first half of the twentieth century historical documents elaborated by enlightened physicians were seminal, and resulted in the identification of RFGB and their associated vectors in countries such as Mexico, Panama, Colombia, Venezuela, Peru and Argentina. Almost 80 years later, research on relapsing fever spirochetes is emerging once again in Latin America, with molecular characterizations and isolations of novel RFGB members in Panama, Bolivia, Brazil and Chile. In this review we summarize historical aspects of RFGB in Latin America and provide an update on the current scenario regarding these pathogens in the region. To accomplish this, we conducted an exhaustive search of all the published literature for the region, including old medical theses deposited in libraries of medical academies. RFGB were once common pathogens in Latin America, and although unnoticed for many years, they are currently the focus of interest among the scientific community. A One Health perspective should be adopted to tackle the diseases caused by RFGB, since these spirochetes have never disappeared and the maladies they cause may be confused with etiologies with similar symptoms that prevail in the region. [ABSTRACT FROM AUTHOR]

Background: Amblyomma sculptum is a hard tick that is associated with domestic animals and the transmission of Brazilian spotted fever. This association has motivated several field studies on this ixodid tick within its distribution area in South America. Thorough knowledge of the seasonal dynamics of A. sculptum in different ecological scenarios is required in order to better understand the biological characteristics of this tick and develop techniques for the control and prevention of diseases transmitted by this vector. In this article, we systematically review the seasonal dynamics of A. sculptum and tick collection methodology. Methods: A systematic search of the Scopus, Web of Science, PubMed and Scielo databases was carried out for articles (including dissertations and theses) on the population dynamics of A. sculptum. The inclusion criterion was the report of seasonal dynamic studies on A. sculptum through surveys carried out for at least 1 year with, as methodology, tick collection in the environment and/or tick count/collection on A. sculptum primary hosts (horses or capybaras). Studies carried out before the reclassification of Amblyomma cajennense sensu lato in 2014, which referred to Amblyomma cajennense in areas where it is currently known that only A. sculptum occurs, were also included. Articles meeting the inclusion criterion, but not available in online databases, were also added based on the authors' experience on the subject. Sixteen articles and one thesis were selected for inclusion in this systematic review. Results: Most of the studies were carried out in the southeastern region of Brazil, with a few also carried out in the northeast, center-west and south of Brazil and northwest of Argentina. Five techniques/methods were applied across these studies: CO2 traps, dragging, flagging, visual searches and tick counting on animals, used alone or in combination. Conclusion: Seasonal dynamics of A. sculptum was found to be similar in almost all of the areas studied, with larvae predominating during the autumn, nymphs in the winter and adults in the spring and summer. [ABSTRACT FROM AUTHOR]

A decision support tool was developed to aid management of problematic parasites in marine fish aquaculture. The tool provides biologically relevant treatment intervals to interrupt the life cycle of ectoparasitic flatworms that occur in global kingfish and amberjack (Seriola spp.) aquaculture. Temperature‐dependent life cycle parameters for the 'skin flukes', Benedenia seriolae and Neobenedenia girellae, and the 'gill fluke', Zeuxapta seriolae, were derived from published data and modelled using non‐linear regressions. Increasing temperatures shortened the duration of most life cycle parameters of all parasites. Salinity had no effect on the timing of life cycle parameters but limited hatching success in hypo‐ and hypersaline conditions. The tool, named BeNeZe after the first two letters of each parasite genera, enables rapid determination of treatment intervals for two consecutive medicinal immersion or 'bathing' treatments—the first to kill adult flatworms attached to fish and the second to prevent maturity of new parasite recruits. As temperature increases, the interval between treatments and the 'window' within which the second treatment should be applied is reduced. The tool can be used for multi‐species infections. The inclusion of parasite taxonomy, biology and behaviour as part of an integrated management strategy is reviewed. Available through an open access app, BeNeZe is intended to be applied in conjunction with farm biosecurity, surveillance, management measures and recognition of independent management units. BeNeZe can be used to reduce infection burdens, improve fish welfare and production and reduce treatment number and frequency. [ABSTRACT FROM AUTHOR]

Background: Toxoplasma gondii and Neospora caninum infections in primates are potentially fatal and directly impact the conservation of these animals and public health. Materials and methods: A total of 38 blood/clot samples collected from free‐living and captive neotropical primates undergoing clinical care or found dead by environmental authorities in the Mato Grosso State, Brazil, were analyzed by PCR for DNA detection of T. gondii and N. caninum. Furthermore, eight animals were submitted to immunohistochemistry for the detection of T. gondii. Results: DNA of T. gondii and N. caninum was amplified in 11 (28.95%) 10 (26.32%) of samples analyzed, respectively. Coinfection was observed in three individuals. One animal returned a positive result in the immunohistochemistry for the detection of T. gondii. Conclusion: These findings reflect a concern for the conservation of these animals, as the pathogen–host interaction is unpredictable and infections by these protozoa can lead to animal mortality, which has a substantial impact on endangered species. [ABSTRACT FROM AUTHOR]

Information on the altitudinal distribution of the hard ticks Amblyomma aureolatum and Amblyomma ovale in Brazil is scarce and mainly limited to occasional records. In this study we report our evaluation of records on the altitudinal distribution of A. aureolatum and A. ovale collected from dogs and humans and directly from the environment (host-questing ticks), based on active or passive procedures. The collections were conducted in rural areas of municipalities in the state of Rio de Janeiro, Brazil between 2013 and 2017. Active procedures consisted of dragging or flagging, visual examination of vegetation and removal of ticks present on the authors' clothing or on infested dogs. Overall, 222 ticks were collected. The altitudes at the collection sites ranged from 98 to 1220 m a.s.l. We noted a significant difference in the altitudinal distribution of A. aureolatum and A. ovale (Mann–Whitney U-test, U = 518.5, P < 0.001). The overlap of these two species occurred at altitudes of between 650 and 900 m a.s.l. The results indicated that the higher the altitude, the greater the probability for the occurrence of A. aureolatum and, conversely, the lower the likelihood for the occurrence of A. ovale. The findings of this study improve currrent knowledge on the bioecology of these tick species and have implications for studies on the epidemiology of spotted fever in Brazil. [ABSTRACT FROM AUTHOR]

Background: Leishmaniosis is an endemic zoonotic disease in the Mediterranean basin caused by Leishmania infantum and transmitted by phlebotomine sandflies. While in dogs disease may be severe, leishmaniosis is also a public health concern as was shown in the largest outbreak of human leishmaniosis (HL) in Europe in 2009 occurring in the Madrid region. The aim of the present study was to assess the applicability of the Leishmaniosis Surveillance Program (LeishSP) established in Madrid in 1996 by examining trends in L. infantum seroprevalence and associated epidemiological risk factors based on data for the 2007–2018 period. Methods: The study population consisted of 3225 stray dogs from 17 animal shelters collaborating with the LeishSP. Seroprevalences were recorded twice annually (April and November) from 2007 to 2018. In each yearly period, a minimum of 100 dogs were tested to detect dogs infected before and after the sandfly risk season in Madrid area. Each dog was subjected to the same protocol of blood sample collection and clinical examination to collect epidemiological data and clinical signs. Anti-Leishmania-specific IgG was determined by IFAT cut-off ≥ 1:100. Results: Overall seroprevalence was 6.1% (198 positive dogs). Epidemiological data indicate a significantly higher seroprevalence in dogs > 4 years old, purebred dogs (Pit Bull and related breeds), and medium to large size dogs. There were no seroprevalence differences according to sex and/or season (April and November). In addition, no significant differences were observed according to whether dogs lived inside or outside the HL outbreak area. Remarkably, of 198 dogs testing positive for L. infantum, 64.6% had no clinical signs, indicating a high proportion of clinically healthy infected dogs that could be a potential source of infection. Conclusions: Results indicate a stable seroprevalence of L. infantum infection after 2006 in stray dogs in Madrid but with a recent slightly increasing trend. These observations support the need to continue with the LeishSP implemented by sanitary authorities of the Madrid Community as an early warning strategy for human and animal leishmaniosis and to enable continued assessment of the epidemiological role of dogs with subclinical infection in this important zoonotic disease. [ABSTRACT FROM AUTHOR]

In Brazil, 19 species of the genus Ornithodoros (Acari: Argasidae) have been reported. The medical and veterinary importance of Ornithodoros ticks has increased substantially in recent decades, with the discovery of various relapsing fever Borrelia infecting Ornithodoros ticks. Herein, argasid ticks were collected during 2019–2020 from caves, abandoned nests and homes in various regions of Ceará State, Brazilian semiarid—Caatinga biome. In total, 289 ticks were collected and identified into five species: Ornithodoros cavernicolous (176 specimens), Ornithodoros fonsecai (81), Ornithodoros mimon (12), Ornithodoros rietcorreai (4), and a fifth species provisionally retained as Ornithodoros sp. Ubajara. Tick identifications were corroborated by a phylogenetic analysis inferred using the 16S rRNA gene. To extend the molecular characterization, DNA samples were tested by an additional PCR assay targeting the nuclear Histone 3 (H3) gene. Because there were no H3 sequences of argasids in GenBank, we extended this PCR assay for additional Ornithodoros species, available in our laboratory. In total, 15 partial sequences of the H3 gene were generated for 10 Ornithodoros species, showing 0% intraspecific polymorphism, and 1.5–11.6% interspecific polymorphism. Phylogenetic analyses inferred segregated Ornithodoros sp. Ubajara as a potential novel species. Our results also highlight the potential of the H3 gene for deeper phylogenetic analyses of argasids. The present study provides new data for argasid ticks of the genus Ornithodoros in the Caatinga biome. Because some of these tick species are human-biting ticks, active surveillance for the incidence of human infection due to Ornithodoros-borne agents is imperative in the Caatinga biome. [ABSTRACT FROM AUTHOR]