title: First report of 16S rRNA methylase ArmA-producing Acinetobacter baumannii and rapid spread of metallo-β-lactamase NDM-1 in Algerian hospitals.
abstract: OBJECTIVE
  The aim of the present study was to characterize the molecular support of resistance to carbapenems, aminoglycosides and fluoroquinolones in carbapenem-resistant Acinetobacter baumannii clinical isolates recovered between January 2011 and April 2013 from Algerian hospitals.
  
  
  METHODS
  Antibiotic susceptibility testing was performed using disk diffusion and Etest methods. Carbapenemase activity was detected using both MALDI-TOF mass spectrometry assay and via microbiological tests. Carbapenem, aminoglycoside and fluoroquinolone resistance determinants were studied by PCR and sequencing. Clonal relationships between strains were determined using Multi Locus Sequence Typing (MLST).
  
  
  RESULTS
  A total of 47 imipenem-resistant A. baumannii were isolated and identified by MALDI-TOF mass spectrometry. All imipenem-resistant strains were positive in the modified Hodge test, and EDTA inhibited the activity of metallo-β-lactamases enzymes in 11 strains. The blaOXA-23 gene was detected in 33 strains and the blaOXA-24 gene in 10 strains. The metallo-β-lactamase blaNDM-1 gene was detected in 11 isolates (23.4%) from Algiers and Sétif, including 7 that co-expressed a blaOXA-23 gene. Resistance to aminoglycosides was due to the production of aminoglycoside-modifying enzymes, AAC(3)-Ia, AADA, ANT(2″)-I, APH(3')-VI, and 16S rRNA methylases, ArmA. The fluoroquinolone resistance was mainly associated with mutations at Ser83Leu and Ser80Leu of the gyrA and parC genes, respectively. MLST revealed five sequence types (STs), 1, 2, 19, 25, and 85. The imipenem-resistant A. baumannii ST2 was the predominant clone (35/47).
  
  
  CONCLUSIONS
  Here we report for the first time clinical multidrug-resistant A. baumannii isolates harboring 16S rRNA methylase gene, armA, and rapid spread of metallo-β-lactamase NDM-1 isolated from patients in Algeria.
authors.affiliation: Unité de recherche sur les maladies infectieuses et tropicales émergentes (URMITE), UM 63, CNRS 7278, IRD 198, INSERM 1095, IHU Méditerranée Infection, Faculté de Médecine et de Pharmacie, Aix-Marseille-Université, Marseille, France; Laboratoire d'Ecologie Microbienne, FSNV, Université de Bejaia, 06000 Bejaia, Algeria.
authors.forename: Sofiane
authors.initials: S
authors.lastname: Bakour
authors.affiliation: Laboratoire d'Ecologie Microbienne, FSNV, Université de Bejaia, 06000 Bejaia, Algeria.
authors.forename: Abdelaziz
authors.initials: A
authors.lastname: Touati
authors.affiliation: Laboratoire d'Ecologie Microbienne, FSNV, Université de Bejaia, 06000 Bejaia, Algeria.
authors.forename: Taous
authors.initials: T
authors.lastname: Bachiri
authors.affiliation: Laboratoire de Microbiologie, CHU de Sétif, Algeria.
authors.forename: Farida
authors.initials: F
authors.lastname: Sahli
authors.affiliation: Service de Microbiologie, Hôpital Central de l'armée, Alger, Algeria.
authors.forename: Djamel
authors.initials: D
authors.lastname: Tiouit
authors.affiliation: Service de Microbiologie, Hôpital Central de l'armée, Alger, Algeria.
authors.forename: Malek
authors.initials: M
authors.lastname: Naim
authors.affiliation: Laboratoire de Microbiologie, CHU de Béjaia, Algeria.
authors.forename: Mounia
authors.initials: M
authors.lastname: Azouaou
authors.affiliation: Unité de recherche sur les maladies infectieuses et tropicales émergentes (URMITE), UM 63, CNRS 7278, IRD 198, INSERM 1095, IHU Méditerranée Infection, Faculté de Médecine et de Pharmacie, Aix-Marseille-Université, Marseille, France. Electronic address: jean-marc.rolain@univ-amu.fr.
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Rolain
mesh_terms: D000151:Acinetobacter Infections / Q000382:microbiology*; D040981:Acinetobacter baumannii / Q000145:classification / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D000462:Algeria; D000617:Aminoglycosides / Q000494:pharmacology; D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D015373:Bacterial Typing Techniques; D052978:Disk Diffusion Antimicrobial Tests; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D024841:Fluoroquinolones / Q000494:pharmacology; D006761:Hospitals; D006801:Humans; D015378:Imipenem / Q000494:pharmacology; D008780:Methyltransferases / Q000096:biosynthesis* / Q000235:genetics; D058885:Multilocus Sequence Typing; D001618:beta-Lactamases / Q000235:genetics* / Q000378:metabolism
chemical_list: D000617:Aminoglycosides; D001426:Bacterial Proteins; D024841:Fluoroquinolones; D015378:Imipenem; D008780:Methyltransferases; D001618:beta-Lactamases; C552864:beta-lactamase NDM-1; C000599728:beta-lactamase OXA-23, Acinetobacter baumannii; C410345:beta-lactamase OXA-24; C063912:carbapenemase
keywords: 16S rRNA methylase; Acinetobacter baumannii; Algeria; Carbapenemase; Metallo-β-lactamase; armA