BOVINE DIARRHEA: STUDY OF THE ETIOLOGY, VIRULENCE AND RESISTENCE TO ANTIMICROBIAL DRUGS OF AGENTS ISOLATED FROM CALVES OF THE RIBEIR

Abstract

Two hundred fecal samples of calves from dairy herds presenting diarrhea were analyzed in group age of one to 90 days, of the region of Ribeirão Preto-SP, aiming at isolating and identifying the main enteropathogens and also to determine the resistence profile to several antimicrobial drugs. Of the analysed samples, 173 (86.5%) strains of E. coli were isolated, being 53 (26.5%) strains enterotoxigenics E. coli (ETEC), whose more frequent serotypes were:O9:K35:K99 (39.6%) and O8K85:K99 (32.0%). The 120 (60.0%) others strains of E. coli were non enterotoxigenic, being more frequent the sorogroups O114 (23.3%), O119 (22.5%) and O111 (15.0%). Also were isolated 12 (6.0%) strains of Clostridium perfringens, five (2.5%) strains of Salmonella Dublin and 86 (43.0%) strains of Cryptosporidium sp. The test of sensibility for antibiotics and chemotherapics, determined for the E. coli strains disclosed a resistence of 100.0% for lincomicin, 99.4% for penicillin G and 85.5% for novobiocin. The S. Dublin strains were resistant to the penicillin G (100.0%), novobiocin and eritromicin (80.0%), lincomicin and cefalotin (60.0%). KEY-WORDS: Calf. Diarrhea. Escherichia coli. Salmonella. Clostridium. Cryptosporidium.