title: High prevalence of multidrug-resistance in Acinetobacter baumannii and dissemination of carbapenemase-encoding genes blaOXA-23-like, blaOXA-24-like and blaNDM-1 in Algiers hospitals.
abstract: OBJECTIVE
  To assess and characterize antibiotic resistance in Acinetobacter baumannii strains recovered from 5 health-care facilities in Algiers.
  
  
  METHODS
  Antibiotic susceptibility testing was performed by agar diffusion and agar dilution methods, resistance genes were identified by PCR and sequencing, and molecular typing of isolates was carried out by enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR).
  
  
  RESULTS
  Among 125 tested isolates, 117 (93.6%) were multidrug-resistant, of which 94 (75.2%) were imipenem resistant. The blaADC and blaOXA-51-like genes were detected in all isolates, in association with ISAba1 sequence in 84% and 8% (imipenem resistant) of isolates, respectively. The blaOXA-23-like and blaOXA-24-like carbapenemase genes were detected in 67.02% and 20.21% of imipenem-resistant isolates, respectively. The blaOXA-23-like gene is linked to ISAba1 or ISAba4 elements. The metallo-β-lactamase NDM-1 gene was found in 10 (10.6%) imipenem-resistant strains from three hospitals, it is linked to ISAba125 element in nine strains. Extended spectrum β-lactamases production was not detected. Imipenem and cefotaxime resistance phenotypes could not be transferred to Escherichia coli by conjugation. Outer membrane protein CarO gene was not detected in four imipenem-resistant isolates. The aac(6')-Ib, sul1, sul2, tetA and tetB genes were present in 5.31%, 36.17%, 77.65%, 1.06% and 65.92% of strains, respectively. Class 1 integrons were detected in 23.4% strains. ERIC-PCR typing showed a genetic diversity among blaOXA-23-like and blaOXA-24-like positive strains, while clonality was observed among blaNDM-1 positives.
  
  
  CONCLUSIONS
  This study highlighted the high prevalence of imipenem resistance in Acinetobacter baumannii in Algiers hospitals mediated mainly by blaOXA-23-like, blaOXA-24-like, and blaNDM-1 genes.
authors.affiliation: Laboratory of Cellular and Molecular Biology, Faculty of Biological Sciences, University of Sciences and Technology Houari Boumediene, P.B. 32 El-Alia, Bab-Ezzouar, 16111, Algiers, Algeria.
authors.forename: Khadidja
authors.initials: K
authors.lastname: Khorsi
authors.affiliation: Laboratory of Cellular and Molecular Biology, Faculty of Biological Sciences, University of Sciences and Technology Houari Boumediene, P.B. 32 El-Alia, Bab-Ezzouar, 16111, Algiers, Algeria.
authors.forename: Yamina
authors.initials: Y
authors.lastname: Messai
authors.affiliation: Hospital Salim Zemirli, Route de Baraki, BP N°71, El Harrach, 16000, Algiers, Algeria.
authors.forename: Moufida
authors.initials: M
authors.lastname: Hamidi
authors.affiliation: University Hospital Isaad Hassani, Rue Ibrahim Hadjeras, Beni Messous, 16206, Algiers, Algeria.
authors.forename: Houria
authors.initials: H
authors.lastname: Ammari
authors.affiliation: Laboratory of Cellular and Molecular Biology, Faculty of Biological Sciences, University of Sciences and Technology Houari Boumediene, P.B. 32 El-Alia, Bab-Ezzouar, 16111, Algiers, Algeria. Electronic address: rbakour@yahoo.fr.
authors.forename: Rabah
authors.initials: R
authors.lastname: Bakour
keywords: Acinetobacter baumannii; Algiers; Carbapenemase; Hospital; Multidrug-resistance; carO