Random Amplified Polymorphic DNA (RAPD) Analysis for Extended Spectrum β-Lactamase Producing Klebsiella pneumonia Isolated from Clinical Specimens in Korea

Klebsiella pneumoniae is the leading cause of nasocomial infection and the most commonly isolated from clinical specimens. Extended-spectrum-β-lactamase (ESBL) producing K. pneumoniae infection was associated with a significantly longer duration of hospital stay and greater hospital charges. The purpose of this study is to investigate the antibiotic resistant patterns and the DNA fingerprint types of extended-spectrum β-lactamase (ESBL) producing K. pneumoniae. 223 K. pneumoniae strains were collected from three general hospitals with more than 500 beds in Busan, Korea from September 2004 to October 2005. The minimum inhibitory concentration (MIC) of antibiotics was measured using the Gram negative susceptibility (CNS) cards of VITEK (Vitek system, Hazelwood Inc., MO). Random amplified polymorphic DNA method was used to detect DNA fingerprint of the organisms. Of the 226 K. pneumoniae isolates 65 ESBL-producing K. pneumoniae strains were detected by the Vitek system and confirmed by the double-disk synergy test. All the 65 K. pneumoniae strains were resistant cefazolin, cefepime, ceftriaxone and aztreonam, and 83.0% of the organisms were resistant to ampicillin / sulbactam, 66.1% to tobramycin, 67.6% to piperacillin / tazobactam 61.5% to ciprofloxacin, and 47.6% to trimethoprim / sulfamethoxazole and 43.0% to gentamicin. The RAPD patterns were distincted as 10 types by three random 10-mer primers (208, 272, 277). Among ten type patterns, three types (Ic, IIb, IIIe) were remarkably represented at patient of infernal department, nerve surgery department, general surgery department, and neonatal room. These results indicate that RAPD can be useful for DNA of strains typing in the epidemiological investigations. Therefore more investigation are needed in order to prevent the ESBL type-producing K. pneumoniae from spreading resistance to oxyimino cephalosphorin antibiotics.