Investigation of enterotoxigenic escherichia coli species which take role in calf diarrhea and detection of their antimicrobial susceptibility

The scope of this study was determination of enterotoxigenic Escherichia coli identification by detection of phenotypic and genotypic methods and determination of antibiotic susceptibilities of isolated strains from animals which had clinical findings such as diarrhea in Aydın province. Between September-December 2015, 50 calves with diarrhea symptoms were found in cattle farms in and around Aydın province. A total of 50 stool swabs taken from diarrheal calves were brought to the laboratory of the Department of Microbiology and Microbiology at the Adnan Menderes University Veterinary Faculty under the cold chain. Identification of E. coli was carried out by phenotypic methods from swab samples. The isolates identified as E. coli were genotypically confirmed by PCR and the presence of enterotoxigenic E. coli was also investigated by PCR. Antibiograms of E. coli strains identified in the last phase of the study were made by disk diffusion method. Isolation and identification of E. coli from 47 (94%) of 50 rectal swab samples examined. A total of 47 E. coli isolates (100%) examined after PCR using E. coli specific primers were found to be positive for uidA gene. Molecularly confirmed E. coli strains were identified as only 1 (2%) strains of enterotoxigenic E. coli when examined for the presence of ETEC-specific est1B gene. Antibiogram tests revealed that E. coli isolates were sensitive to 89% for Gentamycin, 61% for Cefoperazone, 51% for Amoxicillin-Clavulanic Acid, 44% for Danofloxacin, 42% for Enrofloxacin and Penicillin G and Erythromycin 100%, tetracycline and trimethoprim-sulfomethoxazole to 80% and Kanamycin to 76.5%. As a result, 94% of E. coli and 2% of these isolates were identified by phenotypic and genotypic methods from rectal swab samples taken from diarrheal calves in our study. In conclusion of antibiogram tests of E. coli isolates, multiple antibiotic resistance development was observed.