23th European Congress of Clinical Microbiology and Infectious Disease (ECCMID), 2013, 02, 1263─1263

First identification of KPC-4 producing K. pneumonieae and Enterobacter sp. sharing the same plasmid

JungSik Yoo, Hye Mee Kim, Ji Woo Yang, Hwa Su Kim, Jae Yeon Ryu, Yeong Seon Lee

Abstract

Objectives: KPC-2, 3 have spread widely to many countries through combining with the successful clone ST258. However, KPC-4 producing organisms are rarely reported. KPC-4 was first identified in Enterobacter sp. in Scotland and later identified in K. pneumoniae isolates and A. baumannii in Puerto Rico. In 2012, we identified two KPC-4 harboring Enterobacteriaceae in Korea during carbapenemase producing Enterobacteriaceae (CPE) surveillance.
Methods: Antimicrobial susceptibility tests were performed using CLSI methods. The KPC-4 genotype and other resistant genes (blaCTX-M-, blaSHV-, blaTEM-, the blaOXA-1 group, blaOXA-9 group genes, and 16S methylase genes) were confirmed through PCR and sequencing. For plasmid analysis, S1 nuclease-PFGE and restriction profile analysis were performed. A conjugation experiment was attempted using a broth mating-out assay with sodium azide resistant E. coli J53 as a recipient.
Results: Two KPC-4 producing isolates were identified within 3 months from distant hospitals in Korea. The first isolate (K. pneumoniae, CRKP-242) was resistant to imipenem (MIC, 4 mg/L) and intermediate resistance to meropenem (MIC, 2 mg/L). A second isolate (Enterobacter sp., CRENT-91) showed elevated MICs for imipenem (8) and meropenem (16). CRENT-91 was only susceptible to tigecycline and colistin. CRKP-242 additionally carried blaSHV-11, blaTEM-1, and blaCTX-M-15, however, CRENT-91 carried blaSHV-11, blaTEM-1, blaOXA-1, blaCTX-M-22, and armA. The KPC-4 genes of both isolates were located within Tn4401b in an approximately 90kb plasmid that belonged to IncN. PCR results showed that transconjugants carried blaTEM-1 and blaKPC-4 in both isolates. Plasmid restriction analysis (Not I, Sau3A) and a conjugation experiment showed the KPC-4 genes located on the same conjugational plasmid in both isolates.
Conclusions: We did not confirm an epidemiological link between the two patients. However, it was clear that interspecies transfer of KPC-4 carrying plasmid has occurred in some Korean hospitals. Additional efforts for early detection and prevention of spreading of carbapenemase producing Enterobacteriaceae are crucial within all hospitals.

• ISBN or ISSN: 0000-0000

• 본 연구는 질병관리본부 연구개발과제(과제번호 2011-N44001-00) 연구비를 지원받아 수행되었습니다.
• This research was supported by a fund(code 2011-N44001-00) by Research of Korea Centers for Disease Control and Prevention.