Author : Ibrahim AbdelA, Nadia
journal of kerbala university,
2012, Volume 8, Issue 1, Pages 1-4
Both antibiotic discs in agar and liquid broth cultures methods were used in this study. Bacillus cereus strain ATCC 11778 and the strain that isolated from milk locally were tested for antibiotics susceptibility. Both strains are susceptible to cephalexin, ampicillin and lincomycin in broth method to minimal inhibitory concentrations (MIC). Standard strain was sensitive to cephalexin 125µg/ml, ampicillin 1mg/ml and lincomycin 100µg/ml while local strain is sensitive to cephalexin 250µg/ml, ampicillin 10mg/ml and lincomycin 1mg/ml. The following antibiotics tetracycline, cephalexin, neomycin, streptomycin, penicillin 10µg and ceftriaxone 30µg were used in antibiotic disc concentration method. Both strains were sensitive to Tetracycline, cephalexin, neomycin and streptomycin while both strains were resistant to penicillin 10µg and ceftriaxone 30µg. Our results showed that local strain is tougher in susceptibility to the antibiotic s than standard strain.