Lídio Ricardo Bezerra de Melo

Toxoplasma gondii and Neospora caninum in slaughtered pigs from Northeast, Brazil

The aims of this study were to evaluate the presence of anti-Toxoplasma gondii and anti-Neospora caninum antibodies, to identify associated risk factors and to isolate T. gondii from slaughtered pigs in Paraíba State, Brazil. A total of 190 pigs from public slaughterhouses were used in the study. An indirect immunofluorescence test was used to detect antibodies, and the isolation of T. gondii was performed with a bioassay in mice based on tissues from seropositive animals. A total of 50 g of brain, heart and tongue tissue from 37 positive pigs with titres ≥ 1:64 was ground, digested with acidic pepsin and inoculated into mice. The prevalence of anti-T. gondii antibodies was 19.5% (95% CI: 14.1%; 25.8%) (37/190), with titres ranging from 1:64 to 1:2048. Viable T. gondii parasites were isolated from 13 of the 37 (35.1%; 95% CI: 20.2%; 52.5%) seropositive pigs. We found that the virulence of the isolates varied; three of these isolates were able to kill all of the inoculated mice. The risk factors for infection were extensive husbandry and feeding with leftovers. The prevalence of antibodies to N. caninum in pigs was 3.2% (95% CI: 1.2%; 6.7%) (6/190), with titres ranging from 1:100 to 1:3200. None of the variables studied were considered to be risk factors for N. caninum. These results show that the prevalence of anti-T. gondii antibodies in swine is high in Paraíba State, that the percentage of viable T. gondii parasites recovered from these animals is also high and that infection by this parasite is closely related to the management of swine. Despite the low prevalence of N. caninum in pigs, further studies are necessary to determine the importance of this parasite for the species.

Sheep gastrointestinal helminthiasis in the Sertão region of Paraíba State, Northeastern Brazil: prevalence and risk factors.

In this study, we aimed to establish the prevalence and risk factors relating to gastrointestinal helminthiasis, and to characterize the sanitary management practiced among sheep herds in the Sertão region of the state of Paraíba, northeastern Brazil, based on factors that condition the ways of controlling these parasites in these herds. The research was carried out between April and July 2012. We visited 54 farms, where fecal and blood samples were individually collected from 465 animals. On each farm, a questionnaire was applied to gather information on variables relating to potential risk factors. The prevalence of sheep gastrointestinal helminthiasis in the region was 75.9%. At least one animal tested positive for this helminthiasis on 53 (98.1%) of the 54 farms evaluated. The eggs per gram of feces (EPG) analysis showed the following infection burdens: 51.8% with mild infection, 27.1% moderate infection, 9.9% heavy infection and 11.2% fatal infection. Among the sheep farms visited, anthelmintics were used on 81.5% (p <0.05). The most relevant risk factor in this study was the farm area, because it defines the area available for grazing animals. Properties with many animals and little pasture area, which are the most abundant type in the Sertão region of Paraíba, tend to have high prevalence of gastrointestinal helminthiasis, because the animals are more prone to reinfection. The Sertão region of Paraíba presents high prevalence of gastrointestinal helminthiasis among sheep, and the farm area is the most relevant risk factor for the development of these parasites.

First report of typical Brazilian Toxoplasma gondii genotypes from isolates of free-range chickens ( Gallus gallus domesticus ) circulating in the state of Paraíba, Northeast Brazil

This study evaluated, for the first time, the genetic diversity of Toxoplasma gondii isolates from free-range chickens from the state of Paraíba, Northeast Brazil. Tissue samples from 33 chickens from properties in five municipalities of Paraíba (Esperança, Olho d’Água, Malta, Monteiro, and Patos) were bioassayed in mice. The brains of mice infected with T. gondii cysts were used for DNA extraction and genotyping. Genotyping was performed using 11 PCR-RFLP markers and 15 microsatellite (MS) markers. Complete genotyping results were obtained for 29 isolates, with nine genotypes detected by RFLP and 15 genotypes identified by MS. Three genotypes (#273, #274, and #277) have only been recently identified from pigs in the region. Brazilian clonal types BrII and BrIII were identified from one isolate each. Clonal types I, II, and III were not detected by RFLP. Genotype #13 (Caribbean 1), detected in 48.3% (14/29) of isolates from four of the five municipalities investigated, was the most prevalent genotype in the state of Paraíba. However, the MS analysis showed that of these 14 isolates, only four were unique genotypes, and considering the distance between the municipalities from where they were collected, it is possible that only seven are independent isolates while the others are clones. The other genotypes were restricted to different microregions. The results indicate that the Caribbean 1 lineage of T. gondii is circulating widely in Northeast Brazil. The genotypic diversity of T. gondii in the state of Paraíba is high, and microsatellite analysis revealed this diversity with higher resolution than PCR-RFLP.