title: Distribution of 16S rRNA Methylases Among Different Species of Aminoglycoside-Resistant Enterobacteriaceae in a Tertiary Care Hospital in Poland.
abstract: BACKGROUND
  Aminoglycosides are a group of antimicrobial agents still the most commonly used in the treatment of life-threatening bacterial infections in human and animals. The emergence and spread of 16S rRNA methylases, which confer high-level resistance to the majority of clinically relevant aminoglycosides, constitute a major public health concern.
  
  
  OBJECTIVE
  Our goal was to evaluate the distribution of 16S rRNA methylases among different species of Enterobacteriaceae during a five month-long survey in a tertiary hospital in Warszawa, Poland.
  
  
  METHODS
  In the survey, a total of 1770 non-duplicate clinical isolates were collected from all hospital wards in a tertiary hospital in Warszawa, Poland. The survey was conducted between 19 April and 19 September 2010. The ability to produce 16S rRNA methylase was examined by determining MICs for gentamicin, kanamycin, amikacin by means of the agar dilution method. The isolates resistant to high concentration of aminoglycosides were PCR tested for genes: armA, rmtA, rmtB and rmtC. PCR products were subjected to DNA sequencing by the Sanger method. The genetic similarity of the ArmA-producing isolates was analysed by pulsed-filed gel electrophoresis (PFGE).
  
  
  RESULTS
  ArmA was the only 16S rRNA methylase detected in 20 of 1770 tested isolates. The overall prevalence rate of ArmA was 1.13%. In K. pneumoniae (n = 742), P. mirabilis (n = 130), and E. cloacae (n = 253) collected in the survey, the prevalence of ArmA was 0.4%, 0.8% and 5.9%, respectively. The PFGE revealed both horizontal and clonal spread of the armA gene in the hospital.
  
  
  CONCLUSIONS
  The prevalence of 16S rRNA methylase ArmA reported in this study is significantly higher than observed in other countries in Europe.
authors.affiliation: Department of Bacteriology, National Institute of Public Health-National Institute of Hygiene, Warszawa, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Piekarska
authors.affiliation: Department of Bacteriology, National Institute of Public Health-National Institute of Hygiene, Warszawa, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Zacharczuk
authors.affiliation: Department of Bacteriology, National Institute of Public Health-National Institute of Hygiene, Warszawa, Poland.
authors.forename: Tomasz
authors.initials: T
authors.lastname: Wołkowicz
authors.affiliation: Department of Bacteriology, National Institute of Public Health-National Institute of Hygiene, Warszawa, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Rzeczkowska
authors.affiliation: Department of Laboratory Diagnostics, Military Institute of Medicine, Warszawa, Poland.
authors.forename: Elżbieta
authors.initials: E
authors.lastname: Bareja
authors.affiliation: Department of Laboratory Diagnostics, Military Institute of Medicine, Warszawa, Poland.
authors.forename: Monika
authors.initials: M
authors.lastname: Olak
authors.affiliation: Department of Bacteriology, National Institute of Public Health-National Institute of Hygiene, Warszawa, Poland.
authors.forename: Rafał
authors.initials: R
authors.lastname: Gierczyński
mesh_terms: D000617:Aminoglycosides / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D003428:Cross Infection / Q000188:drug therapy / Q000382:microbiology; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D004755:Enterobacteriaceae / Q000145:classification / Q000187:drug effects / Q000235:genetics*; D005787:Gene Frequency; D006801:Humans; D008780:Methyltransferases / Q000235:genetics* / Q000378:metabolism; D008826:Microbial Sensitivity Tests / Q000379:methods; D010802:Phylogeny; D011044:Poland; D012336:RNA, Ribosomal, 16S / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D013045:Species Specificity; D063128:Tertiary Health Care
chemical_list: D000617:Aminoglycosides; D001426:Bacterial Proteins; D012336:RNA, Ribosomal, 16S; D008780:Methyltransferases; C035181:rRNA (adenosine-O-2'-)methyltransferase
keywords: 16S rRNA methylases; ArmA; Enterobacteriaceae