title: Characterization of Acinetobacter baumannii clinical isolates carrying bla(OXA-23) carbapenemase and 16S rRNA methylase armA genes in Yemen.
abstract: OBJECTIVE
  The aim of this study was to investigate the molecular support of resistance to carbapenems, aminoglycosides, and fluoroquinolones in Acinetobacter baumannii clinical isolates collected from Yemen hospital.
  
  
  METHODS
  Three A. baumannii were isolated in February 2013 from three patients hospitalized at Al-Thawra University Hospital in Sana'a, Yemen. Antibiotic susceptibility testing was performed using the disk diffusion and E-test methods. Carbapenemase production was carried out by the modified Hodge test (MHT) and imipenem-ethylenediaminetetraacetic acid (EDTA) methods. Carbapenem, aminoglycoside, and fluoroquinolone resistance determinants were studied by polymerase chain reaction and sequencing. The epidemiological relatedness of the three strains was studied using multilocus sequence typing (MLST).
  
  
  RESULTS
  The isolates were resistant to almost all antibiotics tested with very high imipenem, amikacin, and ciprofloxacin minimum inhibitory concentrations (>32, >256, and >32 mg/L, respectively). The microbiological tests showed that the three A. baumannii were MHT positive, besides, the activity of β-lactamases was not inhibited by EDTA. All the three isolates contained the naturally occurring bla(OXA-51)-like gene and the bla(OXA-23)-like carbapenemase-encoding gene. The 16S rRNA methylase armA gene was detected in the three isolates. In addition, screening for genes encoding the aminoglycoside-modifying enzymes (AMEs) demonstrated that one isolate contained the acetyltransferase gene aac(6')-Ib. Fluoroquinolone resistance was associated with a single mutation Ser83Leu in the quinolone resistance determining region of the gyrA gene in all isolates. The MLST showed that the sequence type (ST) obtained corresponds to ST2 for the three strains.
  
  
  CONCLUSIONS
  Here we report the first identification of multidrug-resistant A. baumannii isolates harboring the bla(OXA-23)-like gene, AMEs [aac(6')-Ib], and the 16S rRNA methylase (armA) in the Yemen hospital.
authors.affiliation: 1 Laboratoire d'Ecologie Microbienne, FSNV, Université A/MIRA de Béjaia , Béjaia, Algérie.
authors.forename: Sofiane
authors.initials: S
authors.lastname: Bakour
authors.forename: Samer Ahmed
authors.initials: SA
authors.lastname: Alsharapy
authors.forename: Abdelaziz
authors.initials: A
authors.lastname: Touati
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Rolain
mesh_terms: D000151:Acinetobacter Infections / Q000188:drug therapy / Q000382:microbiology; D040981:Acinetobacter baumannii / Q000187:drug effects / Q000235:genetics*; D000617:Aminoglycosides / Q000235:genetics; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics*; D024901:Drug Resistance, Multiple, Bacterial / Q000187:drug effects / Q000235:genetics*; D005798:Genes, Bacterial / Q000235:genetics*; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods; D012336:RNA, Ribosomal, 16S / Q000235:genetics*; D015006:Yemen; D001618:beta-Lactamases / Q000235:genetics*; D012359:tRNA Methyltransferases / Q000235:genetics*
chemical_list: D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D012336:RNA, Ribosomal, 16S; D012359:tRNA Methyltransferases; D001618:beta-Lactamases; C063912:carbapenemase