Campylobacter spp. em matrizes cárneas consumidas no Brasil

Abstract

Campylobacter is one of the microorganisms most commonly associated with meat contamination, including beef, pork, and especially poultry. The thesis was organized in three chapters; the first, entitled "General considerations", addresses the general aspects related to the Campylobacter genus, such as species, characteristics, epidemiology and importance in the poultry chain. The second chapter concerns the presence of Campylobacter jejuni, Campylobacter coli and Campylobacter spp. bovine liver and chicken liver produced by trademarks representative of those marketed in Brazil and collected commercially. The prevalence in these meat matrixes was determined, and in the isolates, the species, the presence of virulence genes and the dissemination of the genotypes were identified. A total of 660 samples were analyzed, 138 of pork leg, 138 of chicken liver, 138 of bovine ground duckling and 246 of bovine liver. Confirmation of the species and the presence of the flaA, pldA, ciaB, cadF and cdtABC, luxS, dnaJ and sodB genes were performed by PCR and the homology between the strains determined by RAPD-PCR. The prevalence of Campylobacter was not influenced by the type of matrix, inspection, trademark, year of isolation and form of commercialization (frozen or cooled). Although there is no statistical difference among the matrices, the prevalence in pork leg is similar to that observed in chicken meat in the literature, and the isolates presented a higher number of genes linked to virulence. The set of results of the other matrices indicates that the consumption of these foods do not present danger to the acquisition of Campylobacteriosis. The third chapter aimed to evaluate the genetic similarity of previously isolated Campylobacter species from 246 chicken carcasses (23 C. jejuni, 9 C. coli and 8 Campylobacter spp.), Of commercial brands representative of those commercialized in Brazil. The similarity between the strains was determined by RAPD-PCR and the results obtained were related to their characteristics of virulence, date and place of isolation and antimicrobial resistance. The phylogenetic analysis showed great genotypic diversity in Campylobacter spp., probably due to the existence of different species in this group. In the C. jejuni and C. coli isolates, a high genetic proximity was observed, indicating a common origin. The study shows the complexity observed in the genus Campylobacter, and reinforces the need for constant monitoring of its prevalence and characteristics.