Explosive emergence of CTX-M-15 extended-spectrum b-lactamase in Enterobacteriaceae in Kuwait

Abstract number: 1733_527

Poirel L., Rotimi V., Bernabeu S., Jamal W., Nordmann P.

Objectives: Emergence of expanded-spectrum b-lactamases (ESBL) of the CTX-M group in Enterobacteriaceae has been reported worldwide. Our goal was to identify ESBL genes from a collection of clinically-significant ESBL-producing enterobacterial isolates recovered from the Mubarak hospital in Kuwait City, Kuwait from 2002 to 2004.

Methods: PCR with primers specific for several ESBL genes (blaTEM, blaSHV, blaCTX-M, blaVEB, and blaPER) were used for screening followed by sequencing of PCR products. Primers specific for mobile elements known to be at the origin of blaCTX-M genes acquisition were also used. Strains (one per patient) were collected during a three-year period. ESBL production was suggested by results of liquid medium VITEK 2 analyzer and confirmed by synergy tests performed on solid agar plates. Plasmid profiles analysis was determined by the Kieser method followed by Southern hybridisation with blaCTX-M specific probes.

Results: 598 enterobacterial isolates were recovered during the studied period with 63 ESBL-producers (10.5%). Noteworthy, in 2002 and 2003 respectively, only 2 out of 57 (3.5%) and 6 out of 265 (2.3%) enterobacterial isolates were ESBL producers, whereas they were 55 out of 276 (20%) in 2004. ESBL producers were mostly Escherichia coli (n = 29), Klebsiella pneumoniae (n = 19). In addition, there were several Enterobacter cloacae (n = 4), Enterobacter aerogenes (n = 3), Proteus mirabilis (n = 6), Citrobacter freundii (n = 2) and Serratia marcescens (n = 1). They were from different hospital units, but mostly from Medicine, Surgery and Nephrology departments. The ESBL determinants were mostly of the CTX-M group (50 out of 63), with CTX-M-15 being the main ESBL (46 out of 50). Insertion sequence ISEcp1 was identified systematically upstream of the blaCTX-M-15 gene. The other CTX-M variants were CTX-M-2 and CTX-M-9. The other ESBL-type were mostly SHV-type enzymes, and one isolate was VEB-1 positive.

An heterogeneous pattern of blaCTX-M-borne plasmids was observed that indicated that the dissemination of those resistance determinants were not related to dissemination of a single plasmid.

Conclusion: This study constitutes the first survey on ESBL spread in Kuwait. Dissemination of CTX-M-15 producers was identified as observed worldwide with a threatening increasing detection rate.

Session Details

Date: 31/03/2007
Time: 00:00-00:00
Session name: European Society of Clinical Microbiology and Infectious Diseases
Location: ICC, Munich, Germany
Presentation type:
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