Production of VIM-2 Type Metallo-beta-Lactamase in Urinary Isolates of Providencia rettgeri / 대한진단검사의학회지

ABSTRACT

BACKGROUND: VIM-2 type metallo-beta-lactamase (MBL) producing strains are presently spreading to Pseudomonas spp., Acinetobacter spp. and even to Enterobacteriaceae such as Serratia marcescens, Enterobacter cloacae and Klebsiella pneumoniae in Korea. Recently we determined the phenotype and the genotype of three MBL-producing Providencia rettgeri isolated from urinary specimen of three patients with neurosurgical ward, and analyzed the blaVIM-2 containing integron of a P. rettgeri CBU852. METHODS: EDTA-disk synergy test was used for the screening of MBL, and the PCR for blaIMP-1, blaVIM-1 and blaVIM-2 was performed. The minimal inhibitory concentration of those isolates was determined by broth microdilution method, and the genomic DNA fingerprinting analysis was performed by random amplified polymorphic DNA (RAPD). The sequence of the blaVIM-2 containing integron was determined. RESULTS: Three P. rettgeri with reduced imipenem susceptibility showed the positive EDTA-disk synergy test and blaVIM-2 was detected by PCR. Antimicrobial susceptibility test showed the resistance to all beta-lactams tested, ciprofloxacin and aminoglycoside such as gentamicin, tobramycin and amikacin, indicating multidrug resistance of those isolates. RAPD analysis showed the identical DNA fingerprint of those three isolates. The novel class 1 integron, including aacA4, blaVIM-2, orf "ii" and orf "iii", was detected in a P. rettgeri CBU852. CONCLUSIONS: In this study, the multidrug resistant P. rettgeri CBU852 had blaVIM-2 containing novel class 1 integron. The emergence of blaVIM-2 producing P. rettgeri could compromise the use of carbapenem in treatment of infections caused by MBL producing bacteria. To our knowledge, this is the first report that VIM-2 MBL gene has been detected in P. rettgeri.