Phenotypic detection of beta and metallo lactamases enzymes in Bacillus subtilis strains isolated from raw milk and cheese samples

Bacillus subtilis, a soil bacteria, Gram-positive, rod-shaped, which naturally secretes large amounts of various proteins with high concentrations into the culture medium. The aim of present study was to evaluate the phenotype detection of beta-lactamase and metalo-beta lactamase in Bacillus subtilis strains isolated from samples of milk and cheese.In this study, 100 samples of raw milk and cheese from production and distribution centers received and were cultured. Suspected Bacillus subtilis colonies were identified by biochemical methods. To measure the susceptibility was used Kirby-Bauer method, for broad-spectrum beta-lactamase enzymes and metalo-betalactamase was used Combination Disk and E-test MBL method respectively.The highest amount of resistance in isolates producing beta-lactamase enzyme was related to the antibiotic erythromycin (75%) and the lowest resistance to the antibiotic cefotaxim (44/60%) and cefixime(46/20%). The amount of resistance in isolates producing MBL enzymes was high (100%) with the exception of antibiotics cefotaxim (64/60%) and cefixime (67.40%),the lowest level resistance was observed.The results of this study show food contamination with strains resistant to the antibiotics increases the risk of transferring antibiotic resistance to intestinal bacterial flora of consumers.