Prevalence and seasonal aspects of parasitism by Oestrus ovis (Diptera: Oestridae) in sheep from Mato Grosso State, Brazil

Oestrus ovis larvae are obligate parasites of vertebrates and cause cavitary myiasis (oestrosis) in sheep and goats. It is also reported as a zoonosis causing ophthalmomyiasis and nasopharyngeal myiasis. Despite being relatively common in Brazil, epidemiological studies on O. ovis are scarce. Considering that the infestation is influenced by the climate and biomes of the studied region, we aimed to investigate the seasonal prevalence of O. ovis among slaughtered sheep in the northern region of the state of Mato Grosso, Brazil. The heads of sheep (n=697) slaughtered at a slaughterhouse in the municipality of Terra Nova do Norte (November 2011 to November 2013) were collected to count, catalog, and identify the larvae found in the upper respiratory tract. Overall, 45.77% (319/697) of the animals were infested with 2,412 recovered larvae, 96.89% (2,337/2,412) of which were identified at the species level as O. ovis. Seasonal variations in prevalence ranged from 41% (spring) to 56% (summer); however, no correlation was observed between prevalence and season, mean humidity, or temperature. In conclusion, parasitism by O. ovis in sheep in the studied area, occurs year-round, considering the occurrence of larvae (L1, L2, and L3) throughout the year, probably because of the area's environmental conditions.

Molecular detection and characterization of Bartonella spp. in small mammals in the Amazonia and Cerrado biomes, midwestern Brazil

Although Bartonella spp. have been worldwide described in rodents and bats, few studies have reported these agents in marsupials. The present work aimed to investigate the occurrence and genetic diversity of Bartonella in small mammals (rodents, marsupials, and bats) and associated ectoparasites in two ecoregions (Amazonia and Cerrado biomes) in midwestern Brazil. For this purpose, DNA samples from 378 specimens of small mammals (128 rodents, 111 marsupials, and 139 bats) and 41 fleas (Siphonaptera) were screened for the Bartonella genus employing a quantitative real-time PCR assay (qPCR) based on the nuoG (nicotinamide adenine dinucleotide dehydrogenase gamma subunit) gene. Then, positive samples in qPCR were submitted to conventional PCR (cPCR) assays targeting the gltA, ftsZ, and rpoB genes. One (0.78 %) rodent, 23 (16.54 %) bats, and 3 (7.31 %) fleas showed positive results in the qPCR for Bartonella sp. After cPCR amplification and sequencing, 13 partial Bartonella DNA sequences of the following genes were obtained only from bats´ blood samples: 9 gltA (citrate synthase), 3 ftsZ (cell division protein), and 1 rpoB (RNA polymerase beta subunit). The maximum likelihood inference based on the gltA gene positioned the obtained sequences in three different clades, closely related to Bartonella genotypes previously detected in other bat species and bat flies sampled in Brazil and other countries from Latin America. Similarly, the ftsZ sequences clustered in two different clades with sequences described in bats from Brazil, other countries from Latin America, and Georgia (eastern Europe). Finally, the Bartonella rpoB from a specimen of Lophostoma silvicolum clustered with a Bartonella sp. sequence obtained from a Noctilio albiventris (KP715475) from French Guiana. The present study provided valuable insights into the diversity of Bartonella genotypes infecting bats from two ecoregions (Amazonia and Cerrado) in midwestern Brazil and emphasized that further studies should be conducted regarding the description and evaluation of different lineages of Bartonella in wild small mammals and their ectoparasites in different Brazilian biomes.

Case report of hepatic calodiosis in a rescued dog

Calodium hepaticum (syn. Capillaria hepatica) is a nematode responsible for parasitic zoonosis that can cause granulomatous lesions in the liver. Although murids are the main hosts, C. hepaticum has been documented in a wide range of mammals. Here, we report a case of hepatic calodiosis in a 6-month-old dog that was rescued in the municipality of Cuiabá, Mato Grosso state, midwestern Brazil. Even after being attended at a Veterinary Hospital, the case resulted in animal death. Necroscopic examination revealed significant macroscopic changes in the spleen, liver, and encephalus. Microscopic examination revealed parasitic eggs, identified as Calodium cf. hepaticum, that were rounded to oval with a bilamellar cuticle, radially striated, and with bipolar plugs. Considering the difficulty to diagnose this parasite, and the existence of diverse possible hosts in Mato Grosso due to the biodiversity of the state, further investigation is required to understand the true prevalence of C. hepaticum and the importance of this nematode in public health.

Molecular detection and genetic characterization of Ehrlichia canis and Ehrlichia sp. in neotropical primates from Brazil

The Anaplasmataceae family includes obligate, arthropod-transmitted intracellular bacteria that can be zoonotic and potentially fatal. Studies focusing on the interaction between neotropical primates and the agents of this family are scarce. The present study aimed to identify agents of the Anaplasmataceae family in the whole blood of free-living and captive neotropical primates in the State of Mato Grosso, Central-West Brazil. Thirty-eight samples of six nonhuman primate (NHP) species were collected in seven municipalities and analysed through polymerase chain reaction (PCR), nucleotide sequencing, and phylogenetic analysis of the dsb, groEL, 16S rRNA, and gltA genes. DNA fragments similar to those of Ehrlichia canis were detected in Sapajus apella and Ehrlichia chaffeensis from Mico melanurus. The sequences generated in this study and homologous sequences retrieved from GenBank® were used for phylogenetic analyses to characterize the Ehrlichial agents detected in NHPs. The agents were then grouped into clades corresponding to different isolates from the NHP species. In addition, an Anaplasma sp. closely related to Anaplasma marginale was identified in two S. apella individuals. These findings shed light on the susceptibility of neotropical NHPs to Anaplasmataceae agents. These bacteria are known to be transmitted by ticks, which can also serve as possible sources of infection for other animals, including humans.

Gastrointestinal parasites of wild carnivores from conservation institutions in the Cerrado of Goiás, Brazil

Increased interaction between wild and urban environments owing to human population growth, increased anthropization of biomes, and habitat loss for wild animals increases the spread of infectious and parasitic agents. The present study reports on the occurrence of gastrointestinal parasites in carnivorous mammals at two conservation institutions in the state of Goiás, Brazil. Fecal samples from 39 adult carnivores were collected after spontaneous defecation and analyzed by flotation and sedimentation. The structure and management data of each institution were recorded. Parasitism prevalence, binomial confidence intervals (CI) at 95%, variables associated with the presence of contact animals, size of the enclosure and type of food were recorded. The overall prevalence of gastrointestinal parasites in the samples analyzed was 71.8% (CI 55.1-83.0; 28/39). Ancylostomatidae, Toxocara spp., Toxascaris leonina, Strongyloides spp., Calodium hepaticum, and Trematoda eggs, and Cystoisospora spp. oocysts were detected. Environmental conditions were not correlated with parasitism prevalence; however, the parasites found could be managed, considering their biology, such as controlling synanthropic and domestic animals in captivity, feeding with healthy feed.

Immature hard ticks infected with Rickettsia amblyommatis on breeding birds from Pantanal

Immature hard ticks from the genus Amblyomma feed on blood from a wide range of Neotropical avian hosts. They serve as vectors for pathogens of medical and veterinary importance, such as Rickettsia agents of the spotted fever group (SFG). Hence, determining ecological factors that increase encounter rates between immature ticks and their avian hosts may contribute to the understanding of tick-borne diseases transmission. Here, we used 720 individual birds from 96 species surveyed in the Brazilian Pantanal to test whether host breeding season influenced tick infestation probabilities. Additionally, collected ticks were screened for Rickettsia agents to describe new avian-tick-bacteria associations. Our models revealed that the probability of an individual bird being infested with immature ticks was similar during the breeding and pre-breeding season, but higher loads of immature tick stages were found during the breeding season. Host sex did not predict infestation probability, but Rickettsia agents recovered from ticks were more prevalent during the pre-breeding season. The new records of host usage by larvae and nymphs of Amblyomma in Pantanal and the growing body of tick surveys in Neotropical avian communities, suggest that immature ticks may benefit from avian blood sources during their annual cycle. The low number of infected ticks with Rickettsia agents on Pantanal birds suggest that this vertebrate group are likely not acting as reservoirs for these microorganisms. However, long-term surveys at the same site are imperative to determine which tick species are acting as reservoirs for Rickettsia agents in Pantanal and determine whether birds are playing a role in dispersing ticks and tick-borne pathogens.

Occurrence of gastrointestinal parasites in dogs from Cuiabá, Mato Grosso

Gastrointestinal parasitism by helminths and protozoa poses risks to animal and human health owing to clinical changes and transmission of potentially zoonotic agents. Thus, the present study aimed to verify the occurrence of gastrointestinal parasites in dogs from the municipality of Cuiabá, Mato Grosso, Brazil, using coproparasitological tests. From June 2021 to April 2022, faecal samples were collected from domestic dogs at the Veterinary Hospital and Animal Protection Shelters in the Cuiabá municipality. A semi-structured questionnaire was applied to the owners and those responsible for the shelters to analyse the factors associated with gastrointestinal parasitism. A total of 353 faecal samples were collected and subjected to parasitological flotation and sedimentation techniques. Data were analysed using the chi-squared test and exploratory factorial analysis. The occurrence of gastrointestinal parasitism was 22.66% and the parasites found alone or in mixed infections were Ancylostoma spp., Trichuris vulpis, Toxocara spp., Dipylidium caninum, Cystoisospora spp., Giardia duodenalis, and coccidia. It was concluded that the occurrence of gastrointestinal parasites in dogs is frequent, and the variables associated with these infections were source origin, breed, age, coexistence with other animals, and dull fur.

MORPHOLOGICAL AND GENETIC CHARACTERIZATION OF DIDELPHONEMA LONGISPICULATA (NEMATODA: SPIRUROIDEA) IN THE BLACK-EARED OPOSSUM DIDELPHIS MARSUPIALIS

Didelphonema longispiculata (Hill, 1939), a gastric nematode parasite of the black-eared opossum, Didelphis marsupialis Linnaeus, 1758, collected from 2 municipalities of Mato Grosso state, Brazil, in the ecotone region of the Amazon and Cerrado biomes was analyzed with integrative taxonomy using light and scanning electron microscopy (SEM) for morphological studies and sequencing of the 18S small subunit ribosomal RNA for phylogenetic inference through maximum likelihood and Bayesian phylogenetic inference. Here details of the helminth surface, oral aperture with octagonal border, pseudo- and inter-labia, amphids, external cephalic papillae, 2 dorsal and ventral internal plates distally indented, and stoma with strongly chitinized wall are presented. Caudal male papillae, spicules, female vulva, anus, and caudal tip were detailed using SEM. Morphological characteristics and phylogenetic data corroborated the taxonomic placement of the genus Didelphonema within the subfamily Ascaropsinae.

A new species of Pterygodermatites (Spirurida: Rictulariidae) in Marmosa constantiae Thomas, 1904 from an ecotone area of the biomes Cerrado/Amazon in the Mato Grosso State, Brazil

A new species of nematode, Pterygodermatites (Paucipectines) sinopiensis n. sp. is described based on specimens recovered from the intestine of the white-bellied woolly mice opossum, Marmosa constantiae, trapped in the municipality of Sinop, Mato Grosso state, Brazil. The genus Pterygodermatites has 21 species described in mammals worldwide, and to date, only two species have been described for marsupials in Brazil. The new species is characterized by the presence of 23 small denticles and by the presence of 38–40 and 65 pairs of the cuticular processes in male and female species, respectively. Additionally, male species possess three ventral precloacal fans, and in female species, the cuticular processes are divided into 41 pairs of comb-like and 24 pairs of spine-like processes; the vulva opens approximately in pair 41. This study describes the parasite species fifth of marsupials in the Neotropical region.

Parasitism of Nelore (Bos indicus) calf from northern Brazil by Ctenocephalides felis

Ctenocephalides felis is the most common hematophagous ectoparasite of domestic cats and dogs worldwide, causing allergic dermatitis, anemia, itching, discomfort, and it is responsible for the transmission of many pathogens. In cattle, parasitism is not common but occurs due to the high adaptability of this flea species. This study aimed to report infestation of a Nellore (Bos indicus) calf from Northern Brazil by C. felis and its clinical findings. A 45 kg male calf presented diarrhea, progressive emaciation after 50 days of birth, and flea infestation. Anemia was observed (4.11 × 10⁶/μL of erythrocytes; 20.48% of hematocrit). Coproparasitological examination and molecularly detection of Anaplasma spp. and Babesia spp. indicated negatively. Fleas were collected and taxonomically identified as C. felis. Clinical manifestations of this ectoparasite in cattle were unspecific; however, they can develop severe conditions, such as restlessness and weakness, accompanied by alopecia, emaciation, anemia, and edema of the lower limbs with intense itching and self-excoriation.

Helminth community structure of Didelphis marsupialis (Didelphimorphia, Didelphidae) in a transition area between the Brazilian Amazon and the Cerrado

Although the common opossum, Didelphis marsupialis (Didelphimorphia: Didelphidae) is a species widely distributed in South America, knowledge about their helminth parasites and helminth community structure is scarce. The aims of this study were to describe the species composition and analyze the structure of the helminth community of the common opossum in an area of the Amazonian Arc in northern Mato Grosso. The helminths were recovered, counted, and identified in 32 individuals. Overall, 10,198 specimens were categorized into 9 helminths taxa (seven nematodes, one cestode, and one acanthocephalan). The most abundant species were Aspidodera raillieti, Viannaia hamata, and Travassostrongylus orloffi. No statistically significant differences in helminth abundance and prevalence were observed between host sexes. However, young hosts had higher abundance and prevalence of Didelphonema longispiculata, whereas Oligacanthorhynchus microcephalus had higher abundance and prevalence in adult hosts. This was the first study to analyze the helminth fauna and helminth community structure of D. marsupialis in the Amazonian Arc. This is the first report of the presence of A. raillieti, D. longispiculata, T. orloffi, T. minuta, V. hamata, and O. microcephalus in the state of Mato Grosso, Brazil.

Post mortem protozoan hemoparasites detection in wild mammals from Mato Grosso state, Midwestern Brazil

To a better insight into the epidemiology and genetic diversity of protozoan hemoparasites infections in wild mammals, this study aimed to the post mortem detection of DNA from species of the order Piroplasmida (Babesia sp., Cytauxzoon sp., and Theileria sp.) and suborder Adelorina (Hepatozoon sp.) using polymerase chain reaction based on the 18S rRNA gene followed by genetic sequencing of blood and spleen samples collected from carcasses of 164 free-ranging and captive wild mammals from Mato Grosso state. Among them, one Leopardus pardalis, three Panthera onca, two Puma concolor were positive for Cytauxzoon sp., and six Tapirus terrestris tested positive for Piroplasmida, while one L. pardalis was positive for Hepatozoon sp. Furthermore, an uncharacterized piroplasmid genetically related to Theileria sp. previously detected in cats from Brazil was described in lowland tapirs. Despite the controversy regarding the epidemiological threat of these protozoa, the detection of these tick-borne agents in wild free-living and captive mammals, even when asymptomatic, demonstrates the importance of monitoring, particularly in hotspots such as the state of Mato Grosso, to verify the circulation and genetic diversity, to anticipate the possible emergence of diseases, and even their consequences to other animals as well as humans.

Seroprevalence and risk factors of Toxoplasma gondii in cattle from Unai, Minas Gerais state, Brazil

Toxoplasma gondii is a widespread protozoan parasite that causes infections in animals and humans. The presence of tissue cysts in cattle musculature evidences their epidemiological significance in transmission to humans. The present study aimed to evaluate the seroprevalence of and risk factors of T. gondii seropositivity in beef cattle in the municipality of Unaí, Minas Gerais state, Brazil. Bovine blood samples (n = 612) were collected from 31 herds. Risk factors associated with the animal-level and herd-level seroprevalence were analysed using a questionnaire that investigates the epidemiological aspects of toxoplasmosis. A search for anti-T. gondii antibodies was performed by means of an indirect fluorescent antibody test (IFAT). Analysis of 612 samples showed 369 animals positive for anti-T. gondii antibodies (IFAT ≥64), with a seroprevalence of 60.29% (95% confidence interval (CI): 56.35-64.10). The herd-level seroprevalence was 96.77% (95% CI: 79.00-99.58). Applying a multivariate logistic regression analysis, a test of the association between seroprevalence of T. gondii infection and the potential predictors showed that cats (domestic or wild) with access to the drinking water of cattle were a significant (P = 0.001) predictor. The seroprevalence of T. gondii in cattle destined for human consumption is widely distributed throughout the entire study area. Thus, integrated control measures and strategies are suggested to prevent T. gondii infection in cattle.

High prevalence of anti-Toxoplasma gondii antibodies in beef cattle in Midwestern Brazil

The present study aimed to determine the seroprevalence of anti-Toxoplasma gondii antibodies using an indirect immunofluorescence assay (IFA-IgG) in 3,814 cows aged ≥ 24 months belonging to 353 beef farms in the Mato Grosso state. Additionally, we aimed to identify the possible risk factors associated with seropositivity in Mato Grosso, which encompasses three biomes (Amazon, Cerrado, and Pantanal) of Brazil. Analysis of 3,814 samples observed that 1,307 animals were positive for anti-T. gondii antibodies (IFA-IgG ≥ 64), with an animal-level seroprevalence of 34.27%. Herd-level seroprevalence was 92.07%. In the animal-level model, cows raised in the Amazon and Pantanal biomes and breed studies on European and Zebu or hybrid were found to be at risk for T. gondii seropositivity. Prevalence of anti-T. gondii antibodies in cows destined for human consumption was found to be widely distributed throughout the entire study area. Further studies are required to assess the impact of beef in the possible transmission of toxoplasmosis to humans residing in the region and establish additional control measures for this protozoan mainly on beef herds raised in the Amazon and Pantanal biomes, where the highest values of seroprevalence were observed.

Endoparasites of capybaras (Hydrochoerus hydrochaeris) from anthropized and natural areas of Brazil

This study aimed to evaluate the occurrence of endoparasites in fecal samples of capybaras from anthropized areas in seven cities in the state of São Paulo, southeastern Brazil, and natural areas in two locations in the Pantanal biome. For the parasitological evaluation of samples, feces were subjected to centrifugal sedimentation in water-ether and centrifugal flotation in sucrose solution. Out of the 113 samples examined, 97.3% (110/113) were positive for the presence of helminth eggs and/or protozoan oocysts, with 96.7% (89/92) and 100% (21/21) in capybaras from anthropized and natural areas, respectively. Helminth eggs belonging to the Class Cestoda (Monoecocestus spp.), Class Digenea, and Class Nematoda (Trichostrongyloidea, Strongyloides chapini, Protozoophaga obesa, and Capillaria hydrochoeri) were detected. Coccidia oocysts of Eimeria spp. and Cryptosporidium spp. were detected. The difference found was in the occurrence of S. chapini between anthropized and natural areas, as S. chapini was not detected in natural areas. Capybaras from anthropized areas showed a greater species richness of endoparasites, including species such as Fasciola hepatica and Cryptosporidium spp., that might have zoonotic potential.

Molecular detection of trypanosomatids in neotropical primates in the state of Mato Grosso, Midwest, Brazil

Trypanosomatids are uniflagellate protozoa belonging to the Trypanosomatidae family. The genera Trypanosoma and Leishmania are of paramount importance as they contain species that cause serious diseases, such as Chagas disease and Leishmaniasis, respectively. The objective of the present study was to identify trypanosomatids present in the whole blood of free-living and captive neotropical primates in Mato Grosso State, Midwest Brazil. Between 2017 and 2019, 38 blood samples were collected from seven different neotropical primate species in seven cities in the state. Through molecular techniques, including polymerase chain reaction (PCR) to amplify a fragment of the kinetoplast DNA (kDNA) and 18S ribosomal RNA (18S rRNA) gene, sequencing, and phylogenetic analysis, nine Leishmania spp. [seven L. infantum and two L. (Leishmania) amazonensis] and two Trypanosoma spp. (T. minasense and T. rangeli) were identified. This study contributes to understanding the occurrence and epidemiology of trypanosomatids in Mato Grosso State and the importance of neotropical primates as trypanosome hosts and possible infection sources for other animals and humans. Future identification of other blood pathogens in neotropical primates will assist in disease control and prevention strategies.

Platynosomum fastosum in domestic cats in Cuiabá, Midwest region of Brazil

Platynosomum fastosum, which is distributed in tropical and subtropical regions, is the main parasite in the biliary system of domestic cats. Cats can be asymptomatic or show severe signs of cholangitis. Although the infection is reported throughout Brazil, only post-mortem studies are available from the Midwest region of the country. This cross-sectional study investigated the frequency of P. fastosum parasitism in domestic cats treated at the University Veterinary Hospital in Cuiabá city, Mato Grosso, Brazil, by three coproparasitological techniques (formalin-ether sedimentation, Faust, and Hoffmann), associating clinical, laboratory (haematological, biochemical) and ultrasonographic alterations. Based on the sample calculation, 171 cats were evaluated in the clinical and laboratory and a semi-structured epidemiological questionnaire was designed and used by the tutors. The prevalence observed was 26.90%, with no significant association with sex, reproductive status, age, hunting habit, access to the street, recent anthelmintic treatment, and the guardian's lack of knowledge regarding parasitism. Of the 171 cats evaluated, 55 (32.16%) showed clinical signs suggestive of cholangitis, with a significant association of this variable. Regarding the clinical and pathological variables, mild neutrophilia and elevated serum activity of alanine amino transferase and alkaline phosphatase was observed (but not significantly), while the mean values of eosinophils, leucocytes, total protein, albumin, and globulin were normal. The ultrasound findings were like those previously described. Thus, it was observed that P. fastosum occurs in moderate prevalence in cats from Cuiabá-MT, with a significant association with clinical signs and a regular agreement between the parasitological techniques employed.

Risk factor analysis associated with Neospora caninum in dairy cattle in Western Brazilian Amazon

Neospora caninum is considered to be one of the main causes of abortion among cattle. The present survey was conducted in the municipality of Rolim de Moura, Rondônia State, Brazil. A questionnaire that investigates the epidemiological aspects of neosporosis was used in the analysis of risk factors associated with the animal-level and herd-level prevalence in dairy cattle. A total of 416 bovine blood samples were collected from 30 farms, and N. caninum antibody levels were measured by Indirect Fluorescent Antibody Test (IFAT). Analysis of dairy cattle serum samples revealed the presence of anti-N. caninum antibodies to be 47.36% (n = 197). Risk factors associated with N. caninum infection were the management system and access locations of dogs. The results of the present survey indicated that infection of dairy cattle with N. caninum is widespread in the studied region of Western Amazon, which has implications for prevention and control of neosporosis in this region. Therefore, integrated control strategies and measures are recommended to prevent and control N. caninum infection in dairy cattle. In addition, direct contact between dairy cattle, dogs and wild animals, which can influence the epidemiology of neosporosis, should be investigated further.

Seroprevalence of Toxoplasma gondii and Neospora caninum in sheep intended for human consumption in the Rondônia state, Western Brazilian Amazon

The aim of this study was to carry out a seroepidemiological study of anti-T. gondii and anti-N. caninum antibodies in serum samples from sheep intended for human consumption in the Rondônia state, in the Western Brazilian Amazon, and identify possible risk factors associated with seropositivity. The analysis of the 616 sheep serum samples revealed animal-level seroprevalence of T. gondii in the order of 52.4 % and of N. caninum of 60.6 %. Prevalence of co-infections was 33.4 %. The herd-level seroprevalence was 100 % for both the parasites. Applying of multivariate logistic regression analysis, test of the association between seroprevalence of T. gondii infection and the potential predictors showed that feed, fetal malformation, abortion, neurological problems (lambs), presence of rodents were the significant (P < 0.05) predictors. The variables presence of rodents, cats, wild animals and main activity showed statistical association (P < 0.05) with the seroprevalence of N. caninum. Due to the high prevalence of T. gondii and N. caninum found in this study, the absence of specific slaughterhouses for sheep and raw or undercooked sheep meat for human consumption we concluded that sheep can represent an important source of infection for humans.

Molecular survey of tick-borne pathogens in small mammals from Brazilian Amazonia

Small non-volant mammals (marsupials and small rodents) were captured at three different timepoints from 23 forest fragments across three municipalities (Alta Floresta, Sinop and Cláudia) covering the Amazonian biome of the Mato Grosso State in Midwestern Brazil. The animal tissues (liver and spleen) and blood were screened using molecular tools for the detection of Babesia, Coxiella, Cytauxzoon, Hepatozoon, Theileria, and Anaplasmataceae agents. A total of 230 specimens (78 rodents and 152 marsupials) were trapped. Hepatozoon and Piroplasmorida agents were detected in the common opossums (Didelphis marsupialis). In turn, all samples (blood, liver, or spleen) collected from the small mammals were negative for the genus Coxiella and the family Anaplasmataceae, as detected by polymerase chain reaction (PCR). Phylogenetic analyses inferred from partial sequences of the 18S rRNA gene highlighted the occurrence of new Hepatozoon and Piroplasmorida haplotypes. Future studies determining the role of common opossum (D. marsupialis) in the epidemiological cycles of Hepatozoon and Babesia under natural conditions in the Amazonian biome are necessary.

Antibodies anti-Toxoplasma gondii and anti-Neospora caninum in backyard pigs from the state of Mato Grosso, Brazil

To estimate the seroprevalence of Toxoplasma gondii and Neospora caninum, using an indirect immunofluorescent assay (IFA), and identify the risk factors associated, serum samples were collected from 1,070 pigs from 320 backyard pig farming in the of Mato Grosso state. The animal-level seroprevalence of T. gondii and N. caninum was 32.48% and 13.49%, respectively, with a herd seroprevalence of 55.63% for T. gondii and 27.81% for N. caninum. Feeding the animals with leftovers increases the probability of the presence of anti-T. gondii antibodies in pigs by 1.09-fold. Unlike to T. gondii, feeding with leftovers was found to be negatively associated with N. caninum seropositivity in farm-level analysis and in the animal-level model, so decreasing the chances of positivity. Yet, age was considered a risk factor for N. caninum seropositivity. Further studies are necessary to evaluate the impact of T. gondii infection on backyard pig farming production, and its importance as a source of toxoplasmosis infection in humans in the Mato Grosso state, as well as, the role of domestic pigs in the epidemiology of neosporosis.

Occurrence of autogeny in a population of Ornithodoros fonsecai (Acari: Argasidae)

Ornithodoros fonsecai is an argasid tick that is endemic to Brazil and has been described in the municipality of Bonito, state of Mato Grosso do Sul. Some specimens of this species were found in a cave in the municipality of Nobres, state of Mato Grosso. The specific identification of this population was confirmed by means of morphology and molecular biology. The mitochondrial 16S rDNA partial sequence of this species from Nobres has been deposited in GenBank (MK158949). The objective of this study was to elucidate the biology of O. fonsecai from Nobres, and to report autogeny in this tick population. Along three laboratory generations was observed molting of first nymphal instar to the second instar without feeding, a typical behavior of species included in the subgenus Alectorobius. The first generation (F1) presented five nymphal instars (N1 to N5), and most of adults emerged through molting of N5. The last nymphal instar of second generation (F2) was N4, but most of adults emerged from N3. In the third generation (F3) the last nymphal instar was N5, with most of the adults emerging from N4. In F2, some females (n = 20) originated from N3 began laying eggs without a blood meal. It was observed that those N3 fed twice before they molted to autogenic females. However, autogenic behavior occurred in relation to third generation females (F3) with specimens originating from N4 (n = 12) that were fed only once as nymphs. This behavior has already been reported as obligatory for the genera Otobius and Antricola, while it is facultative for one species of genus Argas and for four species of genus Ornithodoros. However, the present report provides the first record of facultative autogeny for a species of Ornithodoros in Brazil.

Seroprevalence, spatial analysis and risk factors of infection with Neospora caninum in cattle in Brazil's northern Pantanal wetland

Neosporosis is caused by an obligate intracellular protozoan, Neospora caninum . It is considered one of the most widespread and frequent causes of abortion in cattle worldwide. To evaluate the prevalence of anti-N. caninum antibodies and associated risk factors, serum samples were collected from 2,452 bovines at 262 farms in the northern Pantanal, state of Mato Grosso, Brazil. Each farmer was asked to fill out a questionnaire for subsequent epidemiological data analysis. Anti-N. caninum antibodies were detected by means of the indirect immunofluorescent assay (IFA), using a cut-off dilution of 1:100. The overall anti-N. caninum antibodies prevalence was 25.44% (Confidence Interval - CI 95%; 20.10%; 30.78%), and the anti-N. caninum antibodies prevalence per herd was 76.72% (CI 95%; 71.60%; 81.84%). The presence of dogs, occurrence of abortion in cows, and sale of cattle for breeding were statistically associated with seropositivity in herds, while the risk of females being seropositive for N. caninum was higher in animals ≤ 6-years-old and in the presence of dogs. A spatial analysis indicated that the relative risk of the disease is spatially constant and that the farms with the highest prevalence of anti-N. caninum antibodies are located south of the region under study.

Molecular survey and genetic diversity of piroplasmids in equids from Midwestern Brazil

We evaluated the distribution of piroplasmids in equids from the Mato Grosso state in Midwestern Brazil using molecular methods and the interspecific genetic diversity. For this, 1,624 blood samples of equids from 973 farms were examined by PCR, using primer pairs that amplify a fragment of the genes rap-1 and ema-1 of Babesia caballi and Theileria equi, respectively. For molecular characterization and phylogenetic studies, 13 and 60 sequences of the rap-1 and ema-1 genes, respectively, were used to build a dendogram using maximum parsimony. B. caballi and T. equi were detected in 4.11% and 28.16% of the farms, respectively, and molecular prevalence was 2.74% for B. caballi and 25.91% for T. equi. The location of the farms and animals raised in the Pantanal ecoregion influence the probability of equids testing positive for B. caballi and T. equi . Moreover, age and herd purpose were variables significantly associated with T . equi infection. The sequences of B. caballi presented 1.95% intraspecific variability, contrasting with 2.99% in T. equi. Dendrograms for both species demonstrated the presence of subgroups with high values of support of branches. However, it is not possible to associate these groups with geographic origin and/or ecoregion.

Genetic diversity and molecular survey of Trypanosoma (Megatrypanum ) theileri in cattle in Brazil’s western Amazon region

Abstract Trypanosoma (Megatrypanum) theileri is a flagellated protozoan that infects ruminants and it displays high genetic diversity. In this study, we investigated the prevalence rates of this protozoan based on hemoculture and molecular diagnosis. The isolates of T. theileri thus obtained were characterized by molecular markers SSU rDNA and gGAPDH and molecular diagnosis based on Cathepsin L-like gene (PCR-TthCATL). The PCR-TthCATL and hemoculture indicated an overall prevalence rate of 8.13%, and the CATL derived sequence named IB was identified for the first time in cattle in the western Amazon region, as well as IF in Brazil. We also describe a possible new PCR-TthCATL derived sequence in cattle, designated IL.

Infection by Neospora caninum in dairy cattle belonging to family farmers in the northern region of Brazil

Neosporosis is considered a major cause of abortion among cattle worldwide. The aim of this study was to investigate the prevalence of anti-Neospora caninum antibodies in dairy cattle and correlate them with possible risk factors on 63 small farms (family farms) in the municipality of Ji-Paraná, the main milk-producing region of the state of Rondônia, northern Brazil. For this purpose, 621 serum samples were collected from cows and were evaluated by means of the indirect fluorescence antibody test (IFAT). The overall herd prevalence of N. caninum antibodies among the farms (38/63; 60.31%) showed that N. caninum are widespread among the dairy herds in this region, despite only infecting a small proportion of animals (66/621, 10.62%). Occurrences of abortion and birth of weak calves were the only variables that showed as risk factors for the presence of N. caninum. The result from the spatial lag model strongly indicated that birth of weak calves and presence of N. caninum are occurring on farms that are located close to each other, indicating aggregation of disease occurrence.

Feline platynosomiasis: analysis of the association of infection levels with pathological and biochemical findings

Abstract Platynosomiasis is a common feline hepatic disease caused by Platynosomum fastosum (Trematoda - Dicrocoelidae), which is also known as ‘lizard poisoning’. Most reports of feline platynosomiasis show that this disease is sporadic and manifests with uncommon lesions; its pathogenicity is still not well understood. This study aimed to describe liver injuries and enzymatic changes associated with natural P. fastosum infection in 47 stray cats in an endemic area. Overall, 38.3% (18/47) of cats were parasitized, and 2,358 flukes (P. fastosum) were collected (131 – mean intensity of parasitism; 50.2 – mean abundance). The alanine transaminase (ALT) measure was significantly higher in parasitized animals, while alkaline phosphatase (ALP) showed no statistical difference between parasitized and non-parasitized animals. In infected animals, gross pathological lesions and microscopic liver injuries ranged from mild to severe, and were similar to those in previous descriptions of feline platynosomiasis. Nonetheless, the intensity of parasitism was not related to the severity of macroscopic or microscopic hepatic injuries. However, feline platynosomiasis should be considered in the differential diagnosis of feline liver disorders, as well as, in any program of helminth control, even if no clinical abnormalities are present.

Novel Babesia and Hepatozoon agents infecting non-volant small mammals in the Brazilian Pantanal, with the first record of the tick Ornithodoros guaporensis in Brazil

Taking into account the diversity of small terrestrial mammals of the Pantanal, the present study aimed to verify the occurrence of infection by Ehrlichia spp., Anaplasma spp., Rickettsia spp., Hepatozoon spp., Babesia spp. and parasitism by ticks in non-volant small mammals collected in the Brazilian Pantanal. Samples of blood, liver and spleen were collected from 64 captured animals, 22 marsupials and 42 rodents. Pathogen detection was performed by the use of genus-specific Polymerase Chain Reaction (PCR) assays. Ticks collected from the animals consisted of Amblyomma sculptum and Amblyomma triste nymphs, and Ornithodoros guaporensis larvae. None of the vertebrate samples (blood, liver, or spleen) yielded detectable DNA of Rickettsia spp. or Ehrlichia spp. The blood of the rodent Hylaeamys megacephalus yielded an Anaplasma sp. genotype (partial 16S rRNA gene) 99% similar to multiple Anaplasma spp. genotypes around the world. The blood of three rodents of the species Calomys callosus were positive for a novel Hepatozoon sp. agent, phylogenetically related (18S rDNA gene) to distinct Hepatozoon genotypes that have been detected in rodents from different parts of the world. One marsupial (Monodelphis domestica) and three rodents (Thrichomys pachyurus) were positive to novel piroplasmid genotypes, phylogenetically (18S rDNA gene) related to Theileria bicornis, Cytauxzoon manul, and Cytauxzoon felis. The present study provides the first molecular detection of Hepatozoon sp. and piroplasmids in small mammals in Brazil. Additionally, we expanded the distribution of O. guaporensis to Brazil, since this tick species was previously known to occur only in Bolivia.

Survey of helminth parasites of cats from the metropolitan area of Cuiabá, Mato Grosso, Brazil

Besides presenting zoonotic potential, helminths of cats are responsible for gastrointestinal, hepatic, and pulmonary diseases. In order to identify the helminthic fauna, prevalence, mean intensity of parasitism (MIP), and mean abundance population (MAP), 146 cats from the metropolitan area of Cuiabá, Midwestern Brazil, were necropsied. In 98 these animals, 12 species of helminths were identified, comprising (species, prevalence, MIP, and MAP, respectively): nematodes (Ancylostoma braziliense [50,68% - 53,64 - 27,18], Ancylostoma tubaeforme [10,27% - 3,6 - 0,37], Toxocara cati [4,11% - 28,33 - 1,16], Physaloptera praeputialis [2,05% - 6,67 - 0,14], Capillaria feliscati [3,42% - 7,4 - 0,25], and Aelurostrongylus abstrusus [1,37%]); cestodes (Spirometra mansonoides [4,11% - 2,0 - 0,08], Dipylidium caninum [3,42% - 5,2 - 0,18], and Taenia taeniformis [0,68% - 1,0 - 0,01]); trematodes (Platynosomum fastosum [26,03% - 179,53 - 46,73]); acanthocephalans (Centrorhynchus erraticus [3,42% - 3,2 - 0,11]). Ancylostoma spp., and P. fastosum were the most prevalent with the highest MIP and MAP. We observed the presence of species of helminths with zoonotic potential. This is the first time cats parasitized with Centrorhynchus erraticus are reported in the Americas. That genus is commonly observed in wild animals.

Brazilian spotted fever in cart horses in a non-endemic area in Southern Brazil

Brazilian Spotted Fever (BSF) is an often fatal zoonosis caused by the obligate intracellular bacterium Rickettsia rickettsii. The disease is generally transmitted to humans by Amblyomma spp. ticks. Serological evidence of past infection by R. rickettsii has been reported in horses, but the pathogenicity of R. rickettsii in horses remains unknown. Cart horses are still widely used in urban and urban fringe areas in Brazil, and these animals may constitute suitable sentinels for BSF human in these areas, for example, in Sao Jose dos Pinhais, where the first BSF human case in the state of Parana was diagnosed. Serum samples were randomly obtained from 75 cart horses between April 2005 and June 2006 and were tested by means of the indirect immunofluorescence assay (IFA) for antibodies against rickettsia of the spotted fever group. A total of 9.33% of the animals were considered positive, with titers ranging from 64 to 1,024. These results indicate the presence of the agent in such areas, although at low rates.