title: beta-Lactamase activity in Chromobacterium violaceum.
abstract: A strain of Chromobacterium violaceum isolated from a fatally infected patient was found to produce a beta-lactamase. When the organism was grown in drug-free medium, beta-lactamase activity was barely detectable, but when it was grown in the presence of penicillin G, a much larger amount of activity was produced. The beta lactamase was active primarily against cephalosporins; it was sensitive to inhibition by cloxacillin but resistant to p-chloromercuribenzoate. Thus this enzyme closely resembled the common type of beta-lactamase found in Pseudomonas aeruginosa. The organism was relatively susceptible to ticarcillin, carbenicillin, and cefoxitin, which resected hydrolysis by its beta-lactamase, but was quite resistant to 11 other beta-lactam antibiotics. Production of the beta-lactamase appeared to be mediated by chromosomal genes.
mesh_terms: D002440:Cefoxitin / Q000494:pharmacology; D002511:Cephalosporins / Q000378:metabolism; D002729:Chloromercuribenzoates / Q000494:pharmacology; D002861:Chromobacterium / Q000187:drug effects / Q000201:enzymology*; D003023:Cloxacillin / Q000494:pharmacology; D004790:Enzyme Induction; D005796:Genes; D006801:Humans; D008297:Male; D008875:Middle Aged; D010400:Penicillin G; D010405:Penicillinase / Q000096:biosynthesis / Q000378:metabolism*; D010406:Penicillins / Q000494:pharmacology
chemical_list: D002511:Cephalosporins; D002729:Chloromercuribenzoates; D010406:Penicillins; D002440:Cefoxitin; D010405:Penicillinase; D003023:Cloxacillin; D010400:Penicillin G