Isolamento e caracterização de Aeromonas em carcaças suínas

Abstract

Pork production represents a very important economic activity in South Brazil. Today, Brazil hold the forth place in pork meat international marker. The expansion of Brazilian exports depends of the adequation to the international roules of microbiological quality. Among the microorganisms currently found in porc meat, the most importants belong to the genera: Salmonella, Escherichia,, Yersinia, Aeromonas, Listeria, Staphylococcus, Campylobacter, Bacillus, Clostridium. Aeromonas is a genus of emmergent enteropathogenic bacteria found in the intestinal tract of several animals, including pigs. In the present work it was evaluated the occurrence of Aeromonas in carcasses of pig using plating and PCR-lipA methods. The isolates were classified by biochemical tests and RFLP-PCR 16S rRNA, and evaluated for antibiotic resistance and the production of virulence factors. The results obtained showed that PCR amplification of lipA gene represents a rapid, efficient and sensible method to determine the presence of Aeromonas in animal samples. High incidence of Aeromonas in carcasses of pig was verified both by PCR-lipA (97%), and a conventional plating method (86.7%). Bacterial counts in carcasses of pig ranged from 1 to 4 logUFC/100cm2. The most prevalente Aeromonas species isolated from carcasses of pig were A. media (35,7%), A. hydrophila (26,2%) and A. caviae (21,4%). Most isolates showed the production of more than one virulence factor, indicating their pathogenic potential. The hig frequency of sulfametoxazol/trimetoprima and tetraciclina resistant isolates is an indicative of the indiscriminate use of these antibiotics during pig production. In general, the present results reinforce the necessity of Aeromonas evaluation in animal samples and derived products, as well as the potential of PCR-lipA in the qualitative determination of Aeromonas.