title: Dissemination of aminoglycoside-modifying enzymes and 16S rRNA methylases among acinetobacter baumannii and Pseudomonas aeruginosa isolates.
abstract: OBJECTIVE
  The purpose of the present study was to investigate the diversity of the genes encoding aminoglycoside-modifying enzymes (AMEs) and their associations with resistance phenotypes and clonality in Acinetobacter baumannii and Pseudomonas aeruginosa isolates.
  
  
  METHODS
  Seventy six P. aeruginosa and 75 A. baumannii isolates were collected from three University affiliated hospitals in Tehran. MIC determination of amikacin and gentamicin as well as the disk diffusion method for tobramycin, netilmicin, and kanamycin were carried out. Nine AMEs genes and three RNA methylases were investigated in all isolates using the PCR method. Clonality for A. baumannii and P. aeruginosa was investigated using repetitive extragenic palindromic and enterobacterial repetitive intergenic consensus PCR, respectively.
  
  
  RESULTS
  aph(3')-VIa (90.6%) and aph(3')-IIb (61.8%) were the most prevalent AME genes in A. baumannii and P. aeruginosa, respectively. Eight (26%) amikacin highly resistant A. baumannii isolates were positive for armA methylase. Phenotypes and clonality did not link to the genetic determinants of resistance to aminoglycosides in our isolates.
  
  
  CONCLUSIONS
  AMEs genes are disseminated in different clones of A. baumannii and P. aeruginosa isolates in Iran. Other than AMEs, there are more complex and multifactorial mechanisms that result in aminoglycoside-resistant phenotypes.
authors.affiliation: Tabriz Research Center of Infectious and Tropical Diseases, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Aghazadeh
authors.forename: Mohammad Ahangarzadeh
authors.initials: MA
authors.lastname: Rezaee
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Nahaei
authors.forename: Reza
authors.initials: R
authors.lastname: Mahdian
authors.forename: Omid
authors.initials: O
authors.lastname: Pajand
authors.forename: Fereshteh
authors.initials: F
authors.lastname: Saffari
authors.forename: Maryam
authors.initials: M
authors.lastname: Hassan
authors.forename: Zoya
authors.initials: Z
authors.lastname: Hojabri
mesh_terms: D000151:Acinetobacter Infections / Q000188:drug therapy / Q000382:microbiology / Q000635:transmission; D040981:Acinetobacter baumannii / Q000145:classification / Q000201:enzymology / Q000235:genetics* / Q000302:isolation & purification; D000617:Aminoglycosides / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D006801:Humans; D007492:Iran; D019868:Kanamycin Kinase / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D008780:Methyltransferases / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D008826:Microbial Sensitivity Tests; D016133:Polymerase Chain Reaction / Q000379:methods; D011552:Pseudomonas Infections / Q000188:drug therapy / Q000382:microbiology / Q000635:transmission; D011550:Pseudomonas aeruginosa / Q000145:classification / Q000201:enzymology / Q000235:genetics* / Q000302:isolation & purification; D012336:RNA, Ribosomal, 16S / Q000145:classification / Q000235:genetics* / Q000378:metabolism
chemical_list: D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D012336:RNA, Ribosomal, 16S; D008780:Methyltransferases; D019868:Kanamycin Kinase