title: First Detection of GES-5 Carbapenemase-Producing Acinetobacter baumannii Isolate.
abstract: This study was conducted to investigate the molecular epidemiology of resistance in Acinetobacter baumannii isolates collected at a hospital in Riyadh, Saudi Arabia, from January through December 2010. Twenty-seven A. baumannii were highly resistant (MIC90> 256 μg/ml) to ceftazidime, cefepime, and aztreonam. Imipenem resistance was seen in 24 isolates, of which 18 had an minimum inhibitory concentration (MIC) >32 μg/mL. Ciprofloxacin, gentamicin, and amikacin resistance was found in 93%, 52%, and 37% of all the isolates, respectively. Moreover, 8 (30%) isolates showed colistin resistance, and 15 (56%) were found to have MICs ≥4 μg/mL for tigecycline. The frequency of ADC, GES-1, GES-11, and GES-5 were 96.3% (n = 26), 18.5% (n = 5), 11% (n = 3), and 3.7% (n = 1), respectively. OXA-23 was found in 63% (n = 17) of the isolates; ISAba1 was found upstream of OXA-23 in 16. OXA-24/40 was detected in only one strain. Multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE) analysis revealed that the 27 strains were distributed in 8 sequence types (STs) and 16 clonal pulsotypes (A-P). Five singleton STs were identified, including ST15 and ST113-ST116. The emergence of multidrug-resistant A. baumannii is becoming a major concern in Saudi Arabia. Metallo-β-lactamases have no role in carbapenem resistance in this collection. The spread of OXA-23 in our strains occurred across different STs and pulsotypes, unlike what has been observed in many other countries. PFGE typing was more discriminatory than MLST. The high frequency of colistin and tigecycline resistance found in the isolates calls for continuous monitoring. This study describes the first identification of GES-5 conferring carbapenem resistance in A. baumannii.
authors.affiliation: 1 Department of Pharmaceutics, College of Pharmacy, King Saud University , Riyadh, Saudi Arabia .|2 Department of Microbiology and Immunology, Faculty of Pharmacy, Al-Azhar University , Cairo, Egypt .
authors.forename: Mohamed H
authors.initials: MH
authors.lastname: Al-Agamy
authors.affiliation: 3 Centre National de Référence "Résistance aux Antibiotiques," Institut Pasteur , Paris, France .
authors.forename: Katy
authors.initials: K
authors.lastname: Jeannot
authors.affiliation: 4 Department of Microbiology and Immunology, Faculty of Pharmacy, Helwan University , Cairo, Egypt .
authors.forename: Taghrid S
authors.initials: TS
authors.lastname: El-Mahdy
authors.affiliation: 5 College of Medicine, Alfaisal University , Riyadh, Saudi Arabia .
authors.forename: Atef M
authors.initials: AM
authors.lastname: Shibl
authors.affiliation: 5 College of Medicine, Alfaisal University , Riyadh, Saudi Arabia .
authors.forename: Wael
authors.initials: W
authors.lastname: Kattan
authors.affiliation: 3 Centre National de Référence "Résistance aux Antibiotiques," Institut Pasteur , Paris, France .
authors.forename: Patrick
authors.initials: P
authors.lastname: Plésiat
authors.affiliation: 6 Laboratoire associé du CHU de Besançon , Paris, France .
authors.forename: Patrice
authors.initials: P
authors.lastname: Courvalin
mesh_terms: D000151:Acinetobacter Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D040981:Acinetobacter baumannii / Q000145:classification / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D015780:Carbapenems / Q000494:pharmacology; D002511:Cephalosporins / Q000494:pharmacology; D002939:Ciprofloxacin / Q000494:pharmacology; D002999:Clone Cells; D003091:Colistin / Q000494:pharmacology; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D016521:Electrophoresis, Gel, Pulsed-Field; D015870:Gene Expression; D006761:Hospitals; D006801:Humans; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D008826:Microbial Sensitivity Tests; D008911:Minocycline / Q000031:analogs & derivatives / Q000494:pharmacology; D017720:Molecular Epidemiology; D058885:Multilocus Sequence Typing; D012529:Saudi Arabia / Q000453:epidemiology; D065288:Serogroup; D000078304:Tigecycline; D001618:beta-Lactamases / Q000235:genetics* / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D015780:Carbapenems; D002511:Cephalosporins; D007527:Isoenzymes; D002939:Ciprofloxacin; D000078304:Tigecycline; D001618:beta-Lactamases; D008911:Minocycline; D003091:Colistin
keywords: A. baumannii; GES-5; OXA-23; Saudi Arabia; carbapenem resistance; colistin resistance