Wide dissemination of GES-type carbapenemases in Acinetobacter baumannii in. Kuwait

Transcription

1 AAC Accepts, published online ahead of print on 22 October 2012 Antimicrob. Agents Chemother. doi: /aac Copyright 2012, American Society for Microbiology. All Rights Reserved. 1 2 Wide dissemination of GES-type carbapenemases in Acinetobacter baumannii in Kuwait Rémy A. Bonnin, 1 Vincent O. Rotimi, 2 Mona Al Hubail, 2 Elise Gasiorowski, 1 Noura Al Sweih, 2 Patrice Nordmann, 1 and Laurent Poirel 1* Service de Bactériologie-Virologie, INSERM U914 «Emerging Resistance to Antibiotics», Hôpital de Bicêtre, Assistance Publique/Hôpitaux de Paris, Faculté de Médecine et Université Paris-Sud, K.- Bicêtre, France, 1 Department of Microbiology, Faculty of Medicine, Kuwait University, Kuwait Keywords: β-lactamase, GES, OXA-23, carbapenemase, MLST, PFGE Running title: Molecular epidemiology of A. baumannii in Kuwait * Corresponding author. Mailing address: Service de Bactériologie-Virologie-Hygiène, Hôpital de Bicêtre, 78 rue de Général Leclerc, Le Kremlin-Bicêtre Cedex, France. Phone: Fax: nordmann.patrice@bct.aphp.fr 1

2 23 Acinetobacter baumannii is an opportunistic pathogen that is an important source of 24 nosocomial infections. Production of extended-spectrum β-lactamases (ESBLs) of the GES- 25 type are reported increasingly in A. baumannii, and some of these GES-type enzymes possess 26 some carbapenemase activity. Our aim was to analyze the resistance determinants and the 27 clonal relationship of carbapenem non-susceptible A. baumannii clinical isolates recovered 28 from hospitals in Kuwait. A total of sixty-three isolates were analyzed and all were found 29 positive for bla GES -type genes. One isolate harbored the bla GES-14 gene encoding an ESBL with 30 significant carbapenemase activity, whereas the other isolates harbored the bla GES-11 ESBL 31 gene. Thirty-three isolates co-harbored the bla OXA-23 and bla GES-11 genes. The analysis of the 32 genetic location indicated that the bla GES-11/-14 genes were plasmid-located. Noteworthy, the 33 bla OXA-23 and bla GES-11 genes were co-located onto a single plasmid belonging. Nine different 34 pulsotypes were observed among the sixty-three isolates. This study showed the emergence of 35 GES-type ESBLs in A. baumannii in Kuwait, further suggesting that the Middle East region 36 might be a reservoir for carbapenemase-producing A. baumannii. 2

3 37 Introduction 38 Acinetobacter baumannii is an opportunistic pathogen that is an important causative agent of 39 nosocomial infections, such as pneumonia, septicemia, urinary tract infections, and wound 40 infections (17). Multidrug-resistant (MDR) A. baumannii isolates are increasingly reported 41 worldwide, often being the source of nosocomial infections. Treatment of infections due to this 42 microorganism is becoming a serious clinical concern since A. baumannii is very often resistant to 43 multiple antibiotics (17). One of the main mechanisms of resistance to β-lactam molecules in this 44 species is the production of β-lactamases (18). Resistance to carbapenems is mostly related to 45 production of carbapenem-hydrolyzing class D β-lactamases (CHDL) and, to a lesser extent, to 46 metallo-β-lactamases (MBLs). Among these CHDLs, OXA-23 is the most commonly identified 47 CHDL worldwide (18), and the corresponding gene is either plasmid- or chromosomally-located, 48 and associated to insertion sequences ISAba1 or ISAba4 being at the origin of its acquisition (16). 49 Although resistance to carbapenems is mostly related to the production of CHDLs that do not 50 include broad-spectrum cephalosporins in their hydrolytic spectrum, resistance to those latter 51 molecules in A. baumannii usually results from the overexpression of the natural AmpC-type 52 enzyme, but also from acquisition of extended-spectrum β-lactamases (ESBLs) (18). Those ESBLs 53 may correspond to TEM or SHV derivatives but mostly correspond to Ambler class A β-lactamases 54 of the VEB, PER, and GES types (18). ESBLs of the GES type are being reported increasingly in 3

4 55 Gram-negative rods, including Pseudomonas aeruginosa, Enterobacter cloacae, and Klebsiella 56 pneumoniae (19), and recently in A. baumannii (4, 6, 15). While the hydrolysis profile of GES-1 is 57 similar to that of other ESBLs (20), including penicillins and broad-spectrum cephalosporins, 58 nonetheless it does not hydrolyze monobactams, some GES variants possess a significant 59 carbapenemase activity. A Gly170Ser substitution, located inside the Ω-loop of the catalytic site, 60 change was identified in GES-4, GES-5, and GES-6, those enzymes hydrolysing carbapenems and 61 cephamycins (19). GES-11, identified in A. baumannii and differing from GES-1 by a single amino 62 acid substitutions Gly243Ala change, possesses increased activity against aztreonam (15). GES-14, 63 also identified in A. baumannii and differing from GES-11 by a Gly170Ser amino acid substitution, 64 possesses an extended-spectrum toward carbapenems and cephamycins, in addition to its ability to 65 compromise monobactams, giving rise to a very broad spectrum enzyme active against all β- 66 lactams (6). 67 The aim of the study was to analyze the resistance determinants and the clonal relationship of 68 a collection of carbapenem non-susceptible A. baumannii clinical isolates recovered from different 69 hospitals in Kuwait. 70 MATERIALS AND METHODS 71 Bacterial isolates and susceptibility testing. Sixty-three non-duplicate and carbapenem-non 72 susceptible A. baumannii clinical isolates were included in this study. These isolates were identified 4

5 73 by using the API20NE system (biomérieux, Marcy l Etoile, France), by 16S rdna gene 74 sequencing, and culture at 44 C, as previously described (12). The antibiotic susceptibility of the 75 isolates was determined by the disc diffusion technique on Mueller-Hinton agar. MICs were 76 determined by using E-test strips (AB biomérieux, La Balme-les-Grottes, France) and interpreted 77 according to the CLSI guidelines (8). The production of MBLs was evaluated using E-test as 78 recommended by the manufacturer (AB biomérieux) and by combined disc test as described (5). 79 PCR amplification and sequencing. PCR experiments were performed using standard 80 conditions to search for ß-lactamase genes that have been previously identified in A. baumannii, i.e. 81 narrow-spectrum β-lactamase genes bla SCO-1, and bla RTG-3, ESBL genes bla PER, bla GES, and bla VEB, 82 MBL genes bla NDM, bla VIM, bla IMP, and bla SIM, acquired CHDL genes bla OXA-23, bla OXA-40, bla OXA , and bla OXA-143, and the intrinsic bla OXA-51-like CHDL gene (Table S1). Detection of the ISAba1 84 element upstream of the bla ADC and bla OXA-51 genes was also performed. Primers used in this study 85 are listed in Table S1. Detection of the 16S RNA methylase genes was also performed as described 86 (2). Amplified DNA fragments were purified with the Qiaquick PCR purification kit (Qiagen, 87 Courtaboeuf, France). Both strands of the amplification products obtained were sequenced with an 88 ABI3100 sequencer (Applied Biosystems, Foster City, CA, USA). The nucleotide and deduced 89 protein sequences were analysed with software available over the Internet at the National Center for 90 Biotechnology Information web site ( nlm.nih.gov). 5

6 91 Acinetobacter PCR-based replicon typing (AB-PBRT) has been developed to type plasmid 92 circulating in A. baumannii. In total, 19 PCR amplifications were used as described previously (3). 93 Analysis of the genetic support of β-lactamase genes. In order to determine the genetic 94 location of either carbapenemase or ESBL genes, conjugation assays were performed using A. 95 baumannii BM4547 (rifampicin resistant) and azide-resistant E. coli J53 (Invitrogen, Cergy- 96 Pontoise, France) as recipient strains. Plasmid DNA was extracted by using the Kieser method (14) 97 and electroporation were also performed using A. baumannii CIP70.10 as donor. Selection was 98 based on ticarcillin (50 µg/ml) and sodium azide (100 µg/ml), or rifampicin (100 µg/ml), depending 99 on the recipient strain used. 100 DNA/DNA hybridization analysis was performed by using total plasmid DNA extracted as 101 described above, separated by electrophoresis on 0.8% agarose gels, transferred onto Hybond N+ 102 membranes, and hybridized with enhanced chemiluminescence labeled probes overnight at 42 C. 103 Plasmid locations of the β-lactamase genes were assessed by hybridization of plasmid DNA with 104 DNA probes specific for bla OXA-23 or bla GES genes. 105 Molecular typing and clonal relationship. Isolates were typed by using ApaI 106 macrorestriction analysis and pulsed-field gel electrophoresis (PFGE) according to the 107 manufacturer s recommendations (Bio-Rad, Marnes-la-Coquette, France). Whole-cell DNA of A. 108 baumannii isolates was digested with ApaI for 3h at 37 C (Fermentas, St. Rémy-Les-Chevreuses, 6

7 109 France) as described (16). Electrophoresis was performed on a agarose gel using a CHEF DRII 110 apparatus (Bio-Rad). Isolates were also typed by RAPD using DAF4, M13 primers as previously 111 described (10). 112 Identification of PCR-based sequence groups was conducted by using 2 multiplex PCR assays 113 designed to identify the worldwide clones as described previously (23). Clonal relationships were 114 established by multilocus sequence typing (MLST) by using 7 standard housekeeping loci as 115 described (9). Sequences of the 7 housekeeping genes were analyzed by using an A. baumannii 116 database ( RESULTS AND DISCUSSION 119 Antimicrobial susceptibilities. A total of sixty-three consecutive non-repetitive carbapenem- 120 non susceptible A. baumannii clinical isolates, including 59 invasive strains and 4 colonizers, were 121 obtained from clinical specimens of patients on admission from six hospitals located in different 122 parts of Kuwait, between December 2007 to June Of these 63 isolates, 32 (50.8%) were from 123 patients with proven lower respiratory tract infections, 11 (17.5%) from blood cultures, 7 (11.1%) 124 from urine, 1 (1.6%) from body fluid, and 4 (6.4%) from other sites. Among these sixty-three 125 isolates, all were resistant to broad-spectrum cephalosporins and 54% (34/63) were resistant to 126 carbapenems (Table 1). All isolates were resistant to ciprofloxacin, chloramphenicol, and 7

8 127 sulfonamides, and 92% and 46% were resistant to amikacin and gentamicin, respectively. They all 128 remained susceptible to colistin and rifampicin. Four isolates were resistant to tigecycline (MIC of µg/ml) using guidelines described by Jones et al. (13), and eight isolates were of reduced 130 susceptibility to tigecycline (MICs of 1 µg/ml). 131 Characterisation of β-lactamase genes. Phenotypic assays showed that all isolates 132 remained negative for MBL production. PCR experiments for the detection of the bla NDM-1, bla IMP type, bla VIM -type and bla SIM-1 gave negative results. Synergy tests with discs containing 134 ceftazidime and ticarcillin-clavulanic acid, using cloxacillin containing Mueller-Hinton, agar plates 135 as described (6) gave positive results. PCR followed by sequencing identified the bla GES ESBL 136 genes in all isolates (Table 2). The bla VEB-1 gene and the bla PER-1 gene were not identified. 137 Additionally, PCR experiments followed by sequence analysis led to the identification of the 138 bla OXA-23 gene in 33 isolates, in addition to a natural bla OXA-51 -like gene identified in all isolates 139 (Table 2). Sequencing of the bla OXA-51 -like gene revealed several variants corresponding to bla OXA , bla OXA-64, and bla OXA-71 (26). 141 Genetic support of the bla GES-14 gene and transfer of β-lactam resistance. Plasmid DNA 142 analysis showed that all A. baumannii clinical isolates harbored plasmids of ca kb in-size 143 (data not shown). Mating-out assays gave A. baumannii BM4547 transconjugants harboring either 144 the bla GES-14 or the bla GES-11 gene. All transconjugants obtained using the OXA-23-producing A. 8

9 145 baumannii isolates as donors co-harboured the bla OXA-23 gene. The bla GES-11 -carrying 146 transconjugants exhibited an ESBL phenotype but also showed reduced susceptibility to 147 carbapenems, suggesting a weak hydrolysis of carbapenems by GES-11 potentiated by the efflux 148 overproduction in A. baumannii BM4547. The A. baumannii transconjugants harboring the bla GES positive plasmid showed resistance to carbapenems, confirming that expression of GES-14 led 150 to resistance to carbapenems, as previously reported (6). Finally, all A. baumannii transconjugants 151 expressing both OXA-23 and GES-11 and actually harbored a single plasmid bearing both bla GES and bla OXA-23 genes were resistant to all β-lactams, including carbapenems. All transconjugants 153 showed acquired resistance to chloramphenicol, tetracycline, and aminoglycosides. Southern 154 hybridization performed with bla GES - and bla OXA-23 -specific probes confirmed that these two genes 155 were co-located onto a ca. 95-kb plasmid (data not shown). 156 Attempts to transfer these natural plasmids into E. coli TOP10 as recipient strain by 157 conjugation and electroporation failed. This result suggests that those plasmids possessed a 158 replication module that does not allow replication in E. coli, as previously suggested (6). The 159 typing of these plasmids by Ab-PBRT indicated that all plasmids belonged to the plasmid group 160 Gr6. This group of plasmid has been shown to be highly prevalent in A. baumannii and previously 161 found associated with the bla OXA-23, bla OXA-40, and bla OXA-58 CHDL genes (22). 162 Genetic environment of the bla GES genes. PCR mapping was performed to identify the 9

10 163 genetic structure bracketing the bla GES genes. Downstream of the bla GES-14 gene, the aaca4 gene 164 cassette encoding the AAC(6 )-Ib aminoglycoside acetyltransferase was identified. It was then 165 followed by the dfra7 gene cassette encoding resistance to trimethoprim and then the 3 extremity 166 of class 1 integrons as observed previously (6). As previously observed, the integrase gene 167 upstream of the bla GES genes was truncated in its 5 extremity. The complete In125 was identified, 168 being composed by two class 1 integrons, only for the isolate possessing the bla GES-14 gene. For the 169 isolates carrying the bla GES-11 gene, the 5 extremity of the In125 was not identified by PCR 170 mapping as observed previously (15). 171 Genetic environment of the bla OXA-23 gene. The insertion sequence ISAba1 was detected 172 upstream of the bla OXA-23 gene in all positive isolates but no ISAba1 was detected downstream of 173 the bla OXA-23 gene, ruling out the hypothesis that this gene could be part of composite transposon 174 Tn2006. Sequence analysis of the region separating ISAba1 from bla OXA-23 gene revealed a 7-bp 175 deletion, corresponding to the sequence previously identified in Tn2008 carrying bla OXA-23 in A. 176 baumannii isolates from USA, Romania and China (1, 7, 25). 177 Genotyping of clinical isolates. Genotypic comparison was performed by using different 178 techniques. RAPD analysis clustered the collection into four groups with a major clonal group 179 (group 1) (Table 2). PFGE analysis showed that the sixty-three isolates were grouped into nine 180 distinct clones named A to I (Table 2). Among these pulsotypes, pulsotype A was the main one 10

11 181 including thirty isolates, B the second including fifteen isolates, and F the third including nine 182 isolates, the other groups including either one or two isolates. The pulsotypes A/C/F/G/H/I 183 corresponded to the RAPD group 1, the pulsotype B corresponded to RAPD group 2 and 4, and the 184 pulsotype E corresponded to RAPD group 3. MLST analysis showed that pulsotype A belonged to 185 ST158 ( ), a recently identified ST type ( 186 bin/genopole/pf8/mlstdbnet.pl?file=acin_isolates.xml). All isolates belonging to ST158 were 187 isolated in the same hospital but from different wards. Therefore, this clone appears to be endemic 188 in the Al Jahrah hospital (Table 2). This clone co-produced the two carbapenemases GES-11 and 189 OXA-23 and showed high-level of resistance to carbapenems (Table 1). The pulsotype B belonged 190 to ST49 ( ) which is an ST that has already been identified in USA and the 191 Netherlands (1, 10). This ST is actually a double locus variant of ST3 ( ) which has 192 been widely identified throughout the world and corresponds to the worldwide clone III (11, 24). 193 Isolates corresponding to pulsotypes G and H belonged to ST3, confirming that this ST is prevalent 194 in Kuwait. The third main sequence type corresponds to ST113 ( ) which has been 195 recently described in Saudi Arabia among GES-producing A. baumannii (21), or ST178 ( ) being a single locus variant of ST113. The remaining clones belonged to worldwide clone II 197 derivatives, being either ST2 ( ) or ST104 ( ), that latter being a single 198 locus variant of ST2. This clone has also been shown to be widely distributed throughout the world 11

12 199 and associated with production of CHDLs (1, 9, 11, 17). Noticeably, only two isolates belonging to 200 clonal complex II were identified among our isolates. Overall, clonal lineages identified in Kuwait 201 were significantly different from those reported in Europe where ST1 and ST2 are the major clones 202 recovered (9, 11, 23). Only few isolates belonging to ST2 were identified here, while no one 203 belonging to ST1 was found. This may be explained by the fact that our collection was recovered 204 during the period of time. 205 CONCLUSION 206 That study revealed a high prevalence of GES-producing A. baumannii strains in Kuwait, that 207 was not linked to a single clone, even if one clone appeared to be more commonly identified (47%) 208 within the sixty-three isolates studied. Recently, a study performed in Belgium also reported a 209 series of GES-producing A. baumannii from which a link with different geographical origins 210 including Middle East countries, Palestinian territories, Turkey, and Egypt was evidenced (4). 211 Overall, those results strongly suggest that the Middle East may be an important reservoir of GES- 212 type carbapenemases. We showed here that the dissemination of those genes was not linked to a 213 clonal strain dissemination but rather to a plasmid dissemination. Noticeably, the plasmid was 214 either carrying the bla GES carbapenemase gene alone, or was also co-harboring the bla OXA carbapenemase gene, making it more efficient to promote high level resistance to carbapenems 216 when acquired in A. baumannii. 12

13 Acknowledgments 219 This work was partially funded by a grant from the INSERM (U914), UMR Université Paris-Sud, 220 France, by grants from the European Community (R-GNOSIS, FP7/HEALTH-F , 221 MAGIC-BULLET, FP7/HEALTH-F , and TEMPOtest-QC, FP7/HEALTH ), and by a Kuwait University Research Administration Grant (No YM01/08). 223 References Adams-Haduch JM, Paterson DL, Sidjabat HE, Pasculle AW, Potoski BA, Muto CA, Harrison LH, Doi Y Genetic basis of multidrug resistance in Acinetobacter baumannii clinical isolates at a tertiary medical center in Pennsylvania. Antimicrob. Agents Chemother. 52: Bercot B, Poirel L, Nordmann P Updated multiplex polymerase chain reaction for detection of 16S rrna methylases: high prevalence among NDM-1 producers. Diagn. Microbiol. Infect. Dis. 71: Bertini A, Poirel L, Mugnier PD, Villa L, Nordmann P, Carattoli A Characterization and PCR-based replicon typing of resistance plasmids in Acinetobacter baumannii. Antimicrob.. Agents Chemother. 54: Bogaerts P, Naas T, El Garch F, Cuzon G, Deplano A, Delaire T, Huang TD, Lissoir B, Nordmann P, Glupczynski Y GES extended-spectrum β-lactamases in Acinetobacter baumannii isolates in Belgium. Antimicrob. Agents Chemother. 54:

14 Bonnin RA, Naas T, Poirel L, Nordmann P Phenotypic, biochemical, and molecular techniques for detection of metallo-β-lactamase NDM in Acinetobacter baumannii. J. Clin. Microbiol. 50: Bonnin RA, Nordmann P, Potron A, Lecuyer H, Zahar JR, Poirel L Carbapenemhydrolyzing GES-type extended-spectrum β-lactamase in Acinetobacter baumannii. Antimicrob. Agents Chemother. 55: Bonnin RA, Poirel L, Licker M, Nordmann P Genetic diversity of carbapenemhydrolysing β-lactamases in Acinetobacter baumannii from Romanian hospitals. Clin. Microbiol. Infect. 17: Clinical and Laboratory Standard Institute Performance standards for antimicrobial susceptibility testing (M100-S22). Clinical and Laboratory Standards Institute, Wayne, PA. 9. Diancourt L, Passet V, Nemec A, Dijkshoorn L, Brisse S The population structure of Acinetobacter baumannii: expanding multiresistant clones from an ancestral susceptible genetic pool. PLoS One 5:e Grundmann HJ, Towner KJ, Dijkshoorn L, Gerner-Smidt P, Maher M, Seifert H, Vaneechoutte M Multicenter study using standardized protocols and reagents for evaluation of reproducibility of PCR-based fingerprinting of Acinetobacter spp. J. Clin. Microbiol. 35: Higgins PG, Dammhayn C, Hackel M, Seifert H Global spread of carbapenemresistant Acinetobacter baumannii. J. Antimicrob. Chemother. 65: Ibrahim A, Gerner-Smidt P, Liesack W Phylogenetic relationship of the twenty-one DNA groups of the genus Acinetobacter as revealed by 16S ribosomal DNA sequence analysis. Int. J. Syst. Bacteriol. 47: Jones RN, Ferraro MJ, Reller LB, Schreckenberger PC, Swenson JM, Sader HS Multicenter studies of tigecycline disk diffusion susceptibility results for Acinetobacter spp. 14

15 J. Clin. Microbiol. 45: Kieser T Factors affecting the isolation of CCC DNA from Streptomyces lividans and Escherichia coli. Plasmid 12: Moubareck C, Bremont S, Conroy MC, Courvalin P, Lambert T GES-11, a novel integron-associated GES variant in Acinetobacter baumannii. Antimicrob. Agents Chemother. 53: Mugnier PD, Poirel L, Naas T, and Nordmann P Worldwide dissemination of the bla OXA-23 carbapenemase gene of Acinetobacter baumannii. Emerg. Infect. Dis. 16: Peleg AY, Seifert H, Paterson DL Acinetobacter baumannii: emergence of a successful pathogen. Clin. Microbiol. Rev. 21: Poirel L, Bonnin RA, Nordmann P Genetic basis of antibiotic resistance in pathogenic Acinetobacter species. IUBMB Life 63: Poirel L, Bonnin RA, Nordmann P Genetic support and diversity of acquired extended-spectrum β-lactamases in Gram-negative rods. Infect. Genet. Evol. 12: Poirel L, Le Thomas I, Naas T, Karim A, Nordmann P Biochemical sequence analyses of GES-1, a novel class A extended-spectrum β-lactamase, and the class 1 integron In52 from Klebsiella pneumoniae. Antimicrob. Agents Chemother. 44: Ribeiro A, Al-Agamy MH, Shibl AM, Tawfik AF, Courvalin P, Jeannot K Molecular epidemiology and mechanisms of carbapenem-resistant Acinetobacter baumannii in a Saudi Arabia hospital (P1256). Presented at the 22nd European Congress of Clinical Microbiology and Infectious Diseases (ECCMID), London, England. 22. Towner KJ, Evans B, Villa L, Levi K, Hamouda A, Amyes SG, Carattoli A Distribution of intrinsic plasmid replicase genes and their association with carbapenemhydrolyzing class D β-lactamase genes in European clinical isolates of Acinetobacter baumannii. Antimicrob. Agents Chemother. 55: Turton JF, Gabriel SN, Valderrey C, Kaufmann ME, Pitt TL Use of sequence- 15

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17 Table 1. MICs of β-lactams for A. baumannii clinical isolates K22, K31 and K78, A. baumannii BM4547 (pk2), (pk31) and (pk55) (transconjugant), A. baumannii BM4547 reference strain. MIC (µg/ml) β-lactams A. baumannii A. baumannii A. baumannii A. baumannii A. baumannii A. baumannii A. baumannii isolate K22 isolate K31 isolate K77 BM4547 (pk22) BM4547 (pk31) BM4547 (pk77) BM4547 (GES-11) (GES-14) (GES-11, OXA- (GES-11) (GES-14) (GES-11, OXA- 23) 23) Ticarcillin >256 >256 >256 >256 >256 >256 8 Ticarcillin + CLA > >256 8 Piperacillin >256 >256 >256 >256 >256 >256 4 Piperacillin + TZP > >256 4 Cefoxitin >256 >256 >256 >256 >256 > Cefotaxime >64 >64 >64 >64 >64 >64 >32 Cefotaxime + CLA >1 >1 >1 >1 >1 >1 ND

18 Ceftazidime >64 >64 >64 >64 >64 >64 4 Ceftazidime + CLA >1 >1 >1 >1 >1 >1 ND Cefepime >64 >64 > Aztreonam >64 >64 >64 64 >64 >64 32 Meropenem Doripenem Imipenem CLA; clavulanic acid (4 µg/ml) TZB; tazobactam (4 µg/ml)

19 Table 2. Clinical features, β-lactamase detection and genotyping of A. baumannii clinical isolates Isolate Date of isolation Hospitals Unit Specimen Acquired Carbapenemase OXA- 51-like ISAba1- ampc ESBL EC a //ST b RAPD pattern PFGE pattern K Jahra ICU Endotracheal tube OXA-23 OXA-66 - GES-11 nt c /ST158 1 A K Jahra ICU Endotracheal tube OXA-23 OXA-66 - GES-11 nt/st158 1 A K Jahra ICU Endotracheal tube OXA-23 OXA-66 - GES-11 nt/st158 1 A K Jahra medical Urine culture OXA-23 OXA-66 - GES-11 nt/st158 1 A K Jahra ICU Endotracheal tube OXA-23 OXA-66 - GES-11 nt/st158 1 A K Jahra ICU Urine culture OXA-23 OXA-66 - GES-11 nt/st158 1 A K Jahra ICU Endotracheal tube OXA-23 OXA-66 - GES-11 nt/st158 1 A K Jahra ICU Endotracheal tube OXA-23 OXA-66 - GES-11 nt/st158 1 A K Jahra ICU Endotracheal tube OXA-23 OXA-66 - GES-11 nt/st158 1 A K Jahra ICU Endotracheal tube OXA-23 OXA-66 - GES-11 nt/st158 1 A K Jahra ICU Endotracheal tube OXA-23 OXA-66 - GES-11 nt/st158 1 A K Jahra ICU Endotracheal tube OXA-23 OXA-66 - GES-11 nt/st158 1 A K Jahra ICU Sputum OXA-23 OXA-66 - GES-11 nt/st158 1 A K Jahra Surgical ward OXA-23 OXA-66 - GES-11 nt/st158 1 A K Jahra ICU Leg OXA-23 OXA-66 - GES-11 nt/st158 1 A K Jahra ICU Bed swab OXA-23 OXA-66 - GES-11 nt/st158 1 A K Jahra ICU Endotracheal tube OXA-23 OXA-66 - GES-11 nt/st158 1 A K Jahra ICU Foot wound OXA-23 OXA-66 - GES-11 nt/st158 1 A K Jahra ICU Endotracheal tube OXA-23 OXA-66 - GES-11 nt/st158 1 A K Jahra Medical ward Endotracheal tube OXA-23 OXA-66 - GES-11 nt/st158 1 A

20 K Jahra ICU Endotracheal tube OXA-23 OXA-66 - GES-11 nt/st158 1 A K Jahra Medical ward Endotracheal tube OXA-23 OXA-66 - GES-11 nt/st158 1 A K Jahra Surgical ward Endotracheal tube OXA-23 OXA-66 - GES-11 nt/st158 1 A K Jahra Medical Ward Blood culture OXA-23 OXA-66 - GES-11 nt/st158 1 A K Jahra ICU Endotracheal tube OXA-23 OXA-66 - GES-11 nt/st158 1 A K Jahra Medical ward bal OXA-23 OXA-66 - GES-11 nt/st158 1 A K Jahra ICU Blood culture OXA-23 OXA-66 - GES-11 nt/st158 1 A K Jahra Medical ward Sputum OXA-23 OXA-66 - GES-11 nt/st158 1 A K Jahra Surgical ward Urine culture OXA-23 OXA-66 - GES-11 nt/st158 1 A K Jahra Medical ward Urine culture OXA-23 OXA-66 - GES-11 nt/st158 1 A K Mubarak Medical ward Blood culture GES-11 nt/st49 2 B1 K Adan Neonate ICU Blood culture GES-11 nt/st49 2 B1 K Adan Neonate ICU Blood culture GES-11 nt/st49 2 B1 K Mubarak ICU Endotracheal sec GES-11 nt/st49 2 B1 K Mubarak ICU Blood culture GES-11 nt/st49 2 B1 K Adan Neonate ICU Blood culture GES-11 nt/st49 2 B1 K Adan Medical ward Endotracheal tube GES-11 nt/st49 2 B1 K Mubarak Medical ward Pus GES-11 nt/st49 2 B1 K Babtain Medical ward Urine culture GES-11 nt/st49 2 B1 K Adan Neonate ICU Endotracheal sample GES-11 nt/st49 2 B1 K Mubarak Nephrology ward Dialysis tip GES-11 nt/st49 4 B1 K Adan Neonate ICU Endotracheal tube GES-11 nt/st49 4 B1 K Adan Surgical ward Urine culture GES-11 nt/st49 4 B1 K Adan Neonate ICU Endotracheal tube GES-11 nt/st49 4 B1

21 K Adan Neonate ICU Endotracheal tube GES-11 nt/st49 4 B1 K Adan Neonate ICU Respiratory sample GES-11 nt/st49 4 B1 K Razi Medical ward Urine GES-11 nt/st49 2 B2 K Jahra ICU Tracheal sample OXA-23 OXA-66 + GES-11 II/ST104 2 D K Sabah Medical ward Wound OXA-23 OXA-66 - GES-11 II/ST2 3 E K Mubarak ICU Endotracheal sample - OXA-64 - GES-11 nt/st113 1 C K Mubarak ICU Pus OXA-23 OXA-64 - GES-11 nt/st113 1 C K Mubarak CCU Blood culture - OXA-64 - GES-11 nt/st113 1 F K Mubarak CCU Ventilator swab - OXA-64 - GES-11 nt/st113 1 F K Mubarak ICU Pus - OXA-64 + GES-11 nt/st113 1 F K Razi Medical ward Urine culture - OXA-64 - GES-11 nt/st113 1 F K Adan Neonate ICU Endotracheal tube - OXA-64 - GES-11 nt/st113 1 F K Mubarak ICU Blood culture - OXA-64 - GES-11 nt/st113 1 F K Mubarak ICU Blood culture - OXA-64 - GES-11 nt/st113 1 F K Mubarak ICU Blood culture - OXA-64 - GES-11 nt/st113 1 F K Mubarak ICU Rectal swab - OXA-64 - GES-11 nt/st113 1 F K Mubarak CCU Endotracheal sample - OXA-64 - GES-11 nt/st178 1 G K Adan Medical ward Tracheal sample - OXA-71 - GES-11 III/ST3 1 H K Adan ICU Bed rail GES-14 OXA-71 + GES-14 III/ST3 1 I a Multiplex PCR for determining the clonal complex (23) b Multi-locus sequence typing (9) c nt not typeable