title: Enterococcus in surface waters from the Des Moines River (Iowa) watershed: location, persistence and vancomycin resistance.
abstract: The object of this study was to quantify vancomycin-resistant enterococci in surface water from Central Iowa obtained from April 2007 to August 2007. Water from established sampling sites in four watersheds was plated on bile-esculin agar. Presumptively identified enterococci were categorized as "above the level of concern" if the sample contained ≥ 107 CFU per 100 ml. Confirmation of isolates as enterococci was based on growth at elevated temperature in high salt and on Enterococcus agar. Isolates that grew on 6 μg/ml vancomycin agar were deemed resistant. PCR analysis of resistant strains characterized vancomycin resistance genes. 77.2% of surface water samples from Central Iowa contained enterococci. Among enterococcal isolates, 10.4% grew on media containing 6 μg/ml vancomycin. PCR analysis of resistance genes showed a preponderance of VanC2/C3 in the area studied and VanB was not detected. Vancomycin-resistant Enterococcus is present in Central Iowa surface waters but resistance rarely involved VanA genotypes. Nevertheless, the potential for community-acquired infections remains a risk.
authors: University Research, Des Moines University, 3200 Grand Avenue, Ryan Hall 209, Des Moines, Iowa 50312, USA. Blarsen@marian.edu
authors: Bryan
authors: B
authors: Larsen
authors: Michael K
authors: MK
authors: Essmann
authors: Simon
authors: S
authors: Geletta
authors: Barbara
authors: B
authors: Duff
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics; D019729:Carbon-Oxygen Ligases / Q000235:genetics; D016983:Enterococcus / Q000145:classification / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D007484:Iowa; D010453:Peptide Synthases / Q000235:genetics; D016133:Polymerase Chain Reaction; D045483:Rivers / Q000382:microbiology*; D012621:Seasons; D014640:Vancomycin / Q000494:pharmacology*; D020713:Vancomycin Resistance
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; C071437:VanA ligase, Bacteria; D014640:Vancomycin; D019729:Carbon-Oxygen Ligases; D010453:Peptide Synthases; C108395:VanC protein, Enterococcus