title: Presence of the vancomycin resistance gene cluster vanC1, vanXYc, and vanT in Enterococcus casseliflavus.
abstract: The three chromosomally located clustered genes vanC1, vanXYc, and vanT confer intrinsic resistance to vancomycin and are used for species identification of Enterococcus gallinarum. In this study, 28 strains belonging to the E. gallinarum/casseliflavus group isolated from cloacal swabs from laying hens were screened for the presence of vanC1. As confirmed by species-specific multiplex PCR, 11 vanC1-positive strains were identified as E. gallinarum. Surprisingly, one yellow pigmented strain, verified as E. casseliflavus by species-specific multiplex PCR, was also vanC1 positive; vanXYc and vanT were additionally detectable in this strain. To our knowledge, this is the first report of vanC1, vanXYc, and vanT in E. casseliflavus. The minimum inhibitory concentration of vancomycin was 4 mg/L. Real-time reverse transcription-PCR revealed that none of the clustered genes was expressed in this strain. Even if the genes seem not to be active, there is a certain risk that they will be transferred to other bacteria where they might be functionally expressed. Therefore, it may be advisable to expand the search for vanC1, vanXYc, and vanT from E. gallinarum to other (enterococcal) species. This study confirms that enterococci live up to their name as being reservoir bacteria and should therefore always be closely monitored.
authors.affiliation: 1 Technische Universität München , Freising-Weihenstephan, Germany .
authors.forename: Christina
authors.initials: C
authors.lastname: Hölzel
authors.forename: Johann
authors.initials: J
authors.lastname: Bauer
authors.forename: Eva-Maria
authors.initials: EM
authors.lastname: Stegherr
authors.forename: Karin
authors.initials: K
authors.lastname: Schwaiger
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics* / Q000302:isolation & purification; D015373:Bacterial Typing Techniques; D002268:Carboxypeptidases / Q000235:genetics* / Q000302:isolation & purification; D002645:Chickens / Q000382:microbiology; D016983:Enterococcus / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D005260:Female; D008565:Membrane Proteins / Q000235:genetics* / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D010453:Peptide Synthases / Q000235:genetics* / Q000302:isolation & purification; D046929:Serine-Type D-Ala-D-Ala Carboxypeptidase / Q000235:genetics* / Q000302:isolation & purification; D014640:Vancomycin / Q000494:pharmacology; D020713:Vancomycin Resistance / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D008565:Membrane Proteins; D014640:Vancomycin; D002268:Carboxypeptidases; D046929:Serine-Type D-Ala-D-Ala Carboxypeptidase; C117912:VanY protein, Bacteria; C091956:VanX dipeptidase; D010453:Peptide Synthases; C108395:VanC protein, Enterococcus