Drug Metabolism and Drug Interactions, vol.18, no.1, pp.69-77, 2001 (Scopus)
Some Bacillus species are important food pathogens. For example, B. cereus is an opportunistic pathogen found in raw milk that is a common cause of food poisoning. It is of interest to investigate the virulant profiles of Bacillus strains isolated from foods and samples associated with food-poisoning outbreaks. Nineteen Bacillus strains were isolated from various milk samples. β-Lactamase enzyme activities of these Bacillus strains were evaluated with iodometric and chromogenic cephalosporin (nitrocefin) test methods. Five of 19 Bacillus strains isolated were positive for β-lactamase activity. Clavulanate-amoxycillin and cephazolin were chosen to test the antibiotic susceptibilities of the β-lactamase positive and negative Bacillus strains. Of the five β-lactamase positive Bacillus strains, three were susceptible, and two strains intermediate to clavulanate-amoxycillin; one was susceptible, and four strains were intermediate to cephazolin. None of the β-lactamase positive Bacillus strains was resistant to both antibiotics. Of the 14 β-lactamase negative strains, five were susceptible to clavulanate-amoxycillin, four strains were intermediate, and five strains were resistant; three were susceptible, one intermediate, and ten β-lactamase negative strains were resistant to cephazolin.