title: Natural antibiotic susceptibility and biochemical profiles of Yersinia enterocolitica-like strains: Y. bercovieri, Y. mollaretii, Y. aldovae and 'Y. ruckeri'.
abstract: The natural susceptibility of 54 Yersinia enterocolitica-like strains of Y. bercovieri (formerly Y. enterocolitica biovar 3B, n = 17), Y. mollaretii (formerly Y enterocolitica biovar 3A, n = 12), Y. aldovae (formerly Y. enterocolitica-like group chi2, n = 10) and 'Y ruckeri' (n = 15) was tested to 69 antibiotics. MIC values were determined with a microdilution procedure in IsoSensitest broth for all strains and in cation-adjusted Mueller Hinton broth for some strains. All yersiniae tested showed uniform MIC distributions to most antibiotics and were naturally sensitive or intermediate to aminoglycosides, several cephalosporins, and penicillins, carbapenems, aztreonam, quinolones, tetracyclines, antifolates, chloramphenicol and nitrofurantoin, and naturally resistant to benzylpenicillin, oxacillin, all macrolides except azithromycin, lincosamides, streptogramins, glycopeptides, rifampicin and fusidic acid. Significant differences in susceptibility affecting clinical assessment criteria were seen with aminopenicillins (in the presence and absence of beta-lactamase inhibitors), some cephalosporins (e.g., cefoxitin) and fosfomycin. Whereas strains of Y. aldovae and 'Y. ruckeri' were naturally sensitive or intermediate to amoxicillin and amoxicillin/clavulanate, strains of Y. bercovieri and Y. mollaretii were naturally resistant or naturally resistant or intermediate, respectively. Strains of the two latter species were also highly susceptible to fosfomycin. These data can be valuable for the validation of routine susceptibility test results. beta-Lactam MICs suggest that Y bercovieri and Y. mollaretii strains express chromosomally encoded AmpC beta-lactamases and that most Y. aldovae and 'Y. ruckeri' strains express no, or only small amounts, of enzyme. An evaluation of 30 biochemical tests that determined phenotypic identification to the Yersinia species level is presented.
authors.affiliation: Institute of Medical Microbiology and Immunology, Pharmaceutical Microbiology, University of Bonn, Germany.
authors.forename: Ingo
authors.initials: I
authors.lastname: Stock
authors.affiliation: Institute of Medical Microbiology and Immunology, Pharmaceutical Microbiology, University of Bonn, Germany.
authors.forename: Beate
authors.initials: B
authors.lastname: Henrichfreise
authors.affiliation: Institute of Medical Microbiology and Immunology, Pharmaceutical Microbiology, University of Bonn, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Wiedemann
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D024901:Drug Resistance, Multiple, Bacterial; D008826:Microbial Sensitivity Tests; D010641:Phenotype; D015007:Yersinia / Q000145:classification / Q000187:drug effects* / Q000254:growth & development; D015009:Yersinia Infections / Q000188:drug therapy*
chemical_list: D000900:Anti-Bacterial Agents