Studies investigating rickettsial infections in ticks parasitizing wild animals in the Northeast region of Brazil have been confined to the detection of Rickettsia amblyommii in immature stages of Amblyomma longirostre collected from birds in the state of Bahia, and in immatures and females of Amblyomma auriculariumcollected from the striped hog-nosed skunk (Conepatus semistriatus) and armadillos (Euphractus sexcinctus) in the state of Pernambuco. The current study extends the distribution of R. amblyommii (strain Aranha), which was detected in A. longirostre collected from the thin-spined porcupine Chaetomys subspinosus and the hairy dwarf porcupine Coendou insidiosus. In addition, we report the first detection of Rickettsia bellii in adults of A. longirostre collected from C. insidiosus in the state of Bahia.

This study genetically Toxoplasma gondii isolates obtained from pigs intended for human consumption in northeastern Brazil; multilocus PCR-RFLP and sequencing techniques were utilized. Bioassays were conducted using the brain and tongue of 20 pig heads purchased at butcher shops in the city of Ilheus, Bahia, Brazil. Overall, 11 T. gondii isolates designated TgPgBr06-16 were identified. Application of multilocus PCR-RFLP with seven molecular markers (SAG1, SAG2, SAG3, BTUB, C22-8, PK1 and Apico) identified six different genotypes. Isolates TgPgBr 06, 08, 11, 12, 14 and 15 were indistinguishable by this technique, forming a single genotype; the remaining isolates were characterized as distinct genotypes. However, when five genetic markers (SAG1, SAG2, SAG3, BTUB and c22-8) were employed in multilocus PCR-sequencing, all eleven strains of T. gondii were shown to be different. All isolates differed from Type I, II and III clonal genotypes using both genotyping techniques. These results demonstrate that the multilocus PCR-RFLP assay underestimated the true diversity of the T. gondii population in this study. Thus, DNA sequencing is the preferred technique to infer the genetic diversity and population structure of T. gondii strains from Brazil. Moreover, it is necessary to develop new molecular markers to group and characterize atypical T. gondii isolates from South America.

Graphical abstract

This study aimed to compare the sensitivity of five diagnostic methods commonly used for the detection of Toxoplasma gondii in tissues of naturally infected pigs. We purchased 20 heads of pigs in butcher shops in the city of Ilhéus, Bahia. Brain and tongue fragments were taken from each animal for the performance of PCR against T. gondii. The rest of these two tissues were processed and inoculated into three mice. These rodents were observed for 42 days and euthanized. We prepared slides with brain and lungs of each mouse for the visualization of T. gondii. From the tissues of mice, we carried out polymerase chain reaction (PCR), histopathology, and immunohistochemistry in an attempt to identify the parasite. The PCR direct from the tissue of pigs showed 10% (2/20) of positive samples, all from the brain. PCR in tissue from mice found that 55% (11/20) of pigs were positive: 55% (11/20) and 45% (9/20) for brains and tongues, respectively. Mice were inoculated with material obtained from the samples and examined by various methods for resulting Toxoplasma infection (bioassay). Cyst detection in bioassay mice identified 25% (5/20) and immunohistochemistry 30% (6/20) of the samples pigs as positive for T. gondii. Histopathology of mice tissue could not detect parasite; only suggestive pathological changes such as inflammation with foci of necrosis were seen. The results indicated PCR of mice tissue as the most sensitive among those tested.

No abstract

In this study, we aimed to determine the prevalence of Toxoplasma gondii antibodies and identify risk factors associated with this infection in sheep from the southern region of Bahia state. Between February and December 2010, 795 sheep from 31 farms located in nine municipalities were tested. We found seroprevalence of 30.2% (240/795), with titers of 64 (38.3%), 256 (34.2%), 1,024 (18.3%), and 4,096 (9.2%) by Indirect Fluorescent Antibody Test (IFAT). Seropositive sheep were detected in all farms sampled. Univariate statistical analysis detected association between T. gondii seropositivity and the variables age, use of fresh food mainly, water source, stocking rate, production system, presence and number of cats on the farm, and transit of cats (p < 0.05). In the logistic regression model, transit of cats (p = 0.001), production system (p = 0.007), and age (p = 0.027) were identified as risk factors associated with T. gondii infection.Keywords: Epidemiology, ovine, toxoplasmosis, zoonosis, risk factors. ResumoObjetivou-se com este estudo determinar a prevalência de anticorpos anti-Toxoplasma gondii e identificar os fatores de risco associados à infecção em ovinos no sudeste do Estado da Bahia. De fevereiro a dezembro de 2010, 795 ovinos de 31 propriedades localizadas em nove municípios foram analisados. A soroprevalência foi de 30,2% (240/795), com títulos de 64 (38,3%), 256 (34,2%), 1.024 (18,3%) e 4.096 (9,2%) pela Reação de Imunoflorescência Indireta (RIFI). Ovinos positivos foram detectados em todas as fazendas estudadas. Na análise estatística univariada detectou-se associação entre a soropositividade e idade, uso de alimentação fresca, fonte de água, sistema de produção, presença e número de gatos na fazenda e o transito de gatos (p < 0,05). No modelo de regressão logística, transito de gatos (p = 0,001), sistema de produção (p = 0,007) e idade (p = 0,027) foram identificados como fatores de risco associados à infecção por T. gondii.

No abstract

This study was performed to verify the occurrence of anti-Toxoplasma gondii antibodies in swine raised and slaughtered in the state of Bahia, Brazil. Four hundred sixty five swine blood samples from farms of different cities had been collected and examined. Anti-T. gondii antibodies was detected by the enzyme-linked immunosorbent assay (ELISA) and considered positive all the animals with equal or bigger headings than 1:16. From these, 18.27% (85/465) of total sample were positive for T. gondii, 30.76% (24) in Ilhéus, 18.10% (21/116) in Itabuna and 14.76% (40/271) in Simões Filho. Significant differences were observed regarding animal sex (p = 0.0171), raising system (p = 0.0002) and origin of the animals (p = 0.0278) in the city of Itabuna. The occurrence of anti-T. gondii antibodies shows that swine can be a source of infection for the local human population.