Antimicrobial susceptibility pattern of sorbitol non-fermenting including shiga toxin producing Escherichia coli isolated from Black Bengal goat

Abstract

Sorbitol non-fermenting (SN-F) shiga toxin producing Escherichia coli (STEC) is an important group of emerging zoonotic pathogen, Cattle are recognized as main natural reservoir of these organisms; however, small ruminants like goat, may represent an equally serious risk to harbor the pathogen for human infections as evidenced by recent reports. In this study, we performed antimicrobial sensitivity test on 32 SN-F isolates including 12 STEC collected from Black Bengal goats to determine their susceptibility patterns against 10 antimicrobials. Bauer-Kirby disk-diffusion method was used for the antimicrobial sensitivity test. Seventy-five percent (75%) isolates were sensitive to chloramphenicol and gentamicin, whereas 69% were sensitive to ciprofloxacin and doxycyline. Fifty-six percent were sensitive to ampicillin and amoxicillin. On the other hand, a high resistance profile was found against trimethoprim-sulfomethoxazole (53%) and oxytetracycline (47%). Fifty percent of the isolates containing shiga toxin-producing genes - stx1 and/or stx2 showed resistance to trimethoprim-sulfomethoxazole. Forty-three percent of the isolates having the hlyA gene were resistant to tetracycline, whereas 50% isolates harboring the eae gene to oxytetracycline.