SKUAST Journal of Research

The present investigation was undertaken to study antimicrobial resistance of Bacillus cereus strains (118) isolated from foods of animal origin against a panel of antimicrobial agents (10) by disc diffusion assay. The antibiotics that were found highly effective against the isolates were gentamicin (100%), ciprofloxacin (99.15%), chloramphenicol (91.5%) followed by streptomycin (88.13%). However, a higher level of resistance was recorded against Penicillin-G (91.52%), ampicillin (43.22%), tetracycline (33.05%), linezolid (31.35%), erythromycin (30.50%) and amoxycillin (26.27%). Among a total of 118 isolates 102 (86.44%) of the isolates showed resistance to less than five antibiotics and 16 (13.56%) of isolates showed resistance to more than five antibiotics. Of the 39 phenotypically tetracycline resistant isolates of B. cereus, tetracycline resistant genes namely tetA gene could be detected in 36, tetB in 12 and tetC in none of the isolates by polymerase chain reaction. The detection of tetracycline resistant genes like tetA and tetB in B. cereus is being reported for the first time. Therefore, the occurrence of multidrug resistant B. cereus strains is of public health significance and close association exists between phenotypic resistance against tetracycline and occurrence of tetracycline resistant genes (tetA, tetB) among the isolates.