title: GES-11-producing Acinetobacter baumannii clinical isolates from Tunisian hospitals: Long-term dissemination of GES-type carbapenemases in North Africa.
abstract: Acinetobacter baumannii is an emerging threat in healthcare facilities owing to its ability to be multidrug-resistant (MDR) and to be involved in outbreaks. GES-type extended-spectrum β-lactamases (ESBLs) have been increasingly identified in A. baumannii. In this study, clinical A. baumannii isolates were characterised using standard biochemical methods and antibiotic susceptibility testing. Antibiotic resistance genes were sought by PCR and sequencing. Genetic support was characterised using S1 nuclease pulsed-field gel electrophoresis (PFGE) mapping, conjugation and electroporation assays. The genetic environment was investigated by PCR, and genetic relatedness was investigated by PFGE. Two MDR A. baumannii clinical isolates susceptible only to colistin and rifampicin were isolated from a tracheal aspirate of a 49-year-old woman hospitalised in 2006 at the Military Hospital of Tunis, Tunisia, and from a tracheal aspirate of a 53-year-old man hospitalised in 2010 at the Institut Orthopédique Mohamed El Kassab of Tunis, Tunisia. PCR revealed that the two isolates harboured the acquired carbapenemase blaOXA-23 and ESBL blaGES-11 genes along with chromosomally-encoded blaOXA-51 and blaADC-like genes. PFGE revealed that these A. baumannii isolates were unrelated; nevertheless, plasmid analysis revealed a similar sized plasmid following electrophoresis of the isolates. In addition, A. baumannii CIP70.10 transformants displayed similar resistance patterns. blaGES-11 was integron-borne and the ISAbaI element was identified upstream of blaOXA-23 and blaADC-like. Here we described two unrelated clinical A. baumannii isolates producing GES-11 ESBL and OXA-23 carbapenemase from two Tunisian hospitals. This work further illustrates the emergence of GES-type β-lactamases in A. baumannii in North Africa as early as 2006.
authors.affiliation: Research Unit EA7361, LabEx LERMIT, Faculty of Medicine, Université Paris-Sud, Le Kremlin-Bicêtre, France; Microbiology Unit, Hôpital Militaire de Tunis, Tunis, Tunisia.
authors.forename: H
authors.initials: H
authors.lastname: Chihi
authors.affiliation: Research Unit EA7361, LabEx LERMIT, Faculty of Medicine, Université Paris-Sud, Le Kremlin-Bicêtre, France; French National Reference Center for Antibiotic Resistance, Le Kremlin-Bicêtre, France; Joint Research Unit EERA 'Evolution and Ecology of Resistance to Antibiotics', Institut Pasteur-APHP-Université Paris-Sud, Paris, France; Bacteriology-Hygiene Unit, Hôpital Bicêtre, APHP, Le Kremlin-Bicêtre, France.
authors.forename: R A
authors.initials: RA
authors.lastname: Bonnin
authors.affiliation: Microbiology Unit, Hôpital Militaire de Tunis, Tunis, Tunisia.
authors.forename: A
authors.initials: A
authors.lastname: Bourouis
authors.affiliation: Microbiology Unit, Hôpital Militaire de Tunis, Tunis, Tunisia.
authors.forename: S
authors.initials: S
authors.lastname: Mahrouki
authors.affiliation: Microbiology Unit, Institut Orthopédique Mohamed El Kassab, Tunis, Tunisia.
authors.forename: S
authors.initials: S
authors.lastname: Besbes
authors.affiliation: Biochemistry and Technobiology, Faculty of Sciences of Tunis, Tunis, Tunisia.
authors.forename: M Ben
authors.initials: MB
authors.lastname: Moussa
authors.affiliation: Microbiology Unit, Hôpital Militaire de Tunis, Tunis, Tunisia.
authors.forename: O
authors.initials: O
authors.lastname: Belhadj
authors.affiliation: Research Unit EA7361, LabEx LERMIT, Faculty of Medicine, Université Paris-Sud, Le Kremlin-Bicêtre, France; French National Reference Center for Antibiotic Resistance, Le Kremlin-Bicêtre, France; Joint Research Unit EERA 'Evolution and Ecology of Resistance to Antibiotics', Institut Pasteur-APHP-Université Paris-Sud, Paris, France; Bacteriology-Hygiene Unit, Hôpital Bicêtre, APHP, Le Kremlin-Bicêtre, France. Electronic address: thierry.naas@bct.aphp.fr.
authors.forename: T
authors.initials: T
authors.lastname: Naas
mesh_terms: D000151:Acinetobacter Infections / Q000382:microbiology; D040981:Acinetobacter baumannii / Q000187:drug effects / Q000235:genetics*; D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins / Q000235:genetics*; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D006761:Hospitals; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D014416:Tunisia; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D001618:beta-Lactamases; C063912:carbapenemase
keywords: Acinetobacter baumannii; Carbapenemase; Case report; GES; Tunisia