Characterization of multidrug-resistant and extended-spectrum {beta}-lactamase-producing Klebsiella pneumoniae strains from Malaysian hospitals

• Published in: Journal of medical microbiology Vol. 58; no. 11; p. 1463
• Main Authors: Lim, King Ting, Yeo, Chew Chieng, Md Yasin, Rohani, Balan, Ganeswrie, Thong, Kwai Lin
• Format: Journal Article
• Language: English
• Published: Soc General Microbiol 01.11.2009
• ISSN: 0022-2615; 1473-5644
• DOI: 10.1099/jmm.0.011114-0

1 Institute of Biological Science, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia 2 Faculty of Agriculture and Biotechnology, Universiti Darul Iman Malaysia, 20400 Kuala Terengganu, Malaysia 3 Specialized Diagnostic Centre, Institute of Medical Research, Jalan Pahang, 50588 Kuala Lumpur, Malaysia 4 Hospital Sultanah Aminah Johor Bharu, 80100 Johor Bharu, Malaysia Correspondence Kwai Lin Thong thongkl{at}um.edu.my Received March 23, 2009 Accepted July 9, 2009 The emergence of multidrug-resistant (MDR) and extended-spectrum β -lactamase (ESBL)-producing Klebsiella pneumoniae poses a serious antibiotic management problem as resistance genes are easily transferred from one organism to another. Fifty-one strains of K. pneumoniae isolated from sporadic cases in various hospitals throughout Malaysia were analysed by antimicrobial susceptibility testing, PCR detection of ESBL-encoding genes and DNA fingerprinting. Although 27 of the 51 K. pneumoniae strains were MDR (i.e. resistant to three or more classes of antibiotics), the majority of the strains (98 %) were sensitive to imipenem. PCR detection using ESBL gene-specific primers showed that 46 of the K. pneumoniae strains harboured bla SHV , 19 harboured bla CTX-M , 5 harboured bla OXA-1 and 4 harboured bla TEM-1 . Class 1 integron-encoded intI1 integrase was detected in 21 of the 51 K. pneumoniae strains and amplification of the integron 5'CS region showed the presence of several known antibiotic resistance gene cassettes of various sizes. Results of conjugation and transformation experiments indicated that some of the ESBL-encoding genes (i.e. bla SHV , bla CTX-M and bla TEM-1 ) were transmissible and were likely plasmid-encoded. DNA fingerprinting using PFGE and PCR-based methods indicated that the 51 K. pneumoniae strains were genetically diverse and heterogeneous. A table listing the primers and PCR cycling parameters is available with the online version of this paper.