title: Coliform bacteria isolated from recreational lakes carry class 1 and class 2 integrons and virulence-associated genes.
abstract: OBJECTIVE
  To characterize the integron-harbouring Gram-negative bacteria in recreational lakes, with focus on the genetic content of integrons, antimicrobial resistance profiles and virulence-associated genes.
  
  
  RESULTS
  The presence and structure of integrons in coliform bacteria isolated from the water of four recreational lakes located in Poznań, Poland, was determined by PCR method. Antimicrobial resistance testing was done by disc diffusion method. Virulence-associated genes in integron-bearing Escherichia coli isolates were detected by PCR. A total of 155 integron-bearing strains of coliform bacteria were cultured. Sequence analysis showed the presence of dfrA7, aadA1, dfrA1-aadA1, dfrA17-aadA5 and dfrA12-orfF-aadA2 gene cassette arrays in class 1 integrons and dfrA1-sat2-aadA1 in class 2 integrons. Higher frequency of integron-positive bacteria and higher antimicrobial resistance ranges were noted in colder months (January and November) compared with spring and summer months. The integron-harbouring E. coli carried up to nine virulence-associated genes, with the highest frequency of kpsMT (84.6%) and traT (783%), coding for group 2 capsule and determining human serum resistance respectively.
  
  
  CONCLUSIONS
  Integron-bearing multidrug resistant coliform bacteria carrying virulence genes are present in waters of recreational lakes.
  
  
  CONCLUSIONS
  This study presents antimicrobial resistance and virulence-associated genes in integron-bearing coliform bacteria present in the waters of recreational lakes, which showed that multidrug resistant bacteria with virulence traits might pose a threat to public health. Moreover, the presence of genes typical for enterotoxigenic and Shiga toxin-producing E. coli is a concern.
authors.affiliation: Department of Microbiology, Faculty of Biology, Adam Mickiewicz University in Poznań, Poznań, Poland.
authors.forename: R
authors.initials: R
authors.lastname: Koczura
authors.affiliation: Department of Microbiology, Faculty of Biology, Adam Mickiewicz University in Poznań, Poznań, Poland.
authors.forename: N
authors.initials: N
authors.lastname: Krysiak
authors.affiliation: Department of Microbiology, Faculty of Biology, Adam Mickiewicz University in Poznań, Poznań, Poland.
authors.forename: A
authors.initials: A
authors.lastname: Taraszewska
authors.affiliation: Department of Microbiology, Faculty of Biology, Adam Mickiewicz University in Poznań, Poznań, Poland.
authors.forename: J
authors.initials: J
authors.lastname: Mokracka
mesh_terms: D001419:Bacteria / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification*; D001426:Bacterial Proteins / Q000235:genetics; D032023:Integrons; D060106:Lakes / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D014774:Virulence / Q000235:genetics; D037521:Virulence Factors / Q000235:genetics; D014876:Water Pollution
chemical_list: D001426:Bacterial Proteins; D037521:Virulence Factors
keywords: Escherichia coli; antimicrobial resistance; integrons; public health; virulence