Resumo

NARVAEZ-BRAVO, Claudia A. et al. Isolation of Escherichia coli O157:H7 from Feces in Dual Purpose Cattle at Miranda Municipality, Zulia State, Venezuela. Rev. Cient. (Maracaibo) [online]. 2007, vol.17, n.3, pp.239-245. ISSN 0798-2259.

Escherichia coli O157:H7 is considered a worldwide emerging pathogen which is potentially fatal in humans. Cattle are known as one of the main reservoir of E. coli O157:H7. The aim of this research was to investigate the presence of E. coli O157:H7 in fecal material of dual purpose cattle from the Miranda Municipality at Zulia State, Venezuela. Three-hundred and nine fecal samples of 155 cows and 154 calves from 6 dual purpose farms were processed. Samples were analyzed by conventional bacteriological techniques, biochemical and serological tests, somatic monovalent O157 and flagellar H7. Also, a latex agglutination for somatic antigen O157. A total of six strains (1.94%) positives to the agglutination tests to detect somatic antigen O157 and flagellar H7 were obtained. Additionally a nonmotile O157 strain was also detected (O157:NM). Non significant differences were observed in the shedding of E. coli O157:H7 between cows and calves. The animals who shedding these bacteria did not show clinical signs of illness; therefore, they were considered as asymptomatic carriers. In conclusion, the presence of E. coli O157:H7 in feces from dual purpose cows and calves from this study, revealed that these animals could be considered a feasible source of direct exposure with this zoonotic pathogen, as well as a potential source of contamination of food products derived from those animals.

Palavras-chave : Escherichia coli O157:H7; dual purpose cattle; Venezuela.