title: Relationships between beta-lactamase production and beta-lactam susceptibility of environmental strains of Yersinia kristensenii.
abstract: Strains of Yersinia kristensenii display high susceptibility to carbenicillin (MIC90 less than 8 micrograms/ml) in comparison with the majority of environmental strains of Yersinia closely related to Y. enterocolitica which are resistant to this antibiotic (MIC90 greater than 256 micrograms/ml). beta-lactamases of 39 strains of Y. kristensenii isolated from foods were analysed by isoelectric focusing and gel electrophoresis of ultrasonically disrupted uninduced cultures. beta-lactamase patterns showed the presence of only one out of three classes of enzymes of pI 6.7, 7.6 and 8.2, respectively, by strain. One beta-lactamase showed electrophoretic mobility different (EM + 2.0 cm/h) from that of all the other enzymes (EM + 1.6 cm/h) belonging to the class of pI 7.6. Induction by cefoxitin revealed the existence of inducible beta-lactamases in two out of eight selected strains. The substrate profile of these enzymes, which are probably chromosomally mediated, showed a predominant cephalosporinase activity. None of the type A and B beta-lactamases described by Cornelis and Abraham in Y. enterocolitica were found in any of the strains examined. The lack of beta-lactamase A (a penicillinase) accounts for the carbenicillin susceptibility of Y. kristensenii strains.
authors.affiliation: Laboratoire de Bactériologie, Université Louis Pasteur de Strasbourg, Faculté de Pharmacie, Illkirch, France.
authors.forename: A M
authors.initials: AM
authors.lastname: Ahmedy
authors.forename: D J
authors.initials: DJ
authors.lastname: Vidon
authors.forename: R
authors.initials: R
authors.lastname: Labia
authors.forename: C L
authors.initials: CL
authors.lastname: Delmas
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002440:Cefoxitin / Q000494:pharmacology; D004790:Enzyme Induction / Q000187:drug effects; D004794:Enzyme Repression / Q000187:drug effects; D066298:In Vitro Techniques; D007526:Isoelectric Point; D008826:Microbial Sensitivity Tests; D015007:Yersinia / Q000187:drug effects / Q000201:enzymology*; D001618:beta-Lactamases / Q000032:analysis* / Q000096:biosynthesis
chemical_list: D000900:Anti-Bacterial Agents; D002440:Cefoxitin; D001618:beta-Lactamases