Emergence of serotype K1 Klebsiella pneumoniae ST23 strains co-producing the plasmid-mediated AmpC beta-lactamase DHA-1 and an extended-spectrum beta-lactamase in Korea. Issue 1 (December 2016)

• Record Type: Journal Article
• Authors: Cheong, Hae; Chung, Doo; Lee, Chaeyoeng; Kim, So; Kang, Cheol-In; Peck, Kyong; Song, Jae-Hoon
• Is Part Of: Antimicrobial resistance & infection control. Volume 5:Issue 1(2016)
• Page Start: 1
• Page End: 4
• Publication Date: 2016-12
• Subjects: Klebsiella pneumoniae -- Extended-spectrum beta-lactamase -- AmpC beta-lactamase; Infection -- Treatment -- Periodicals; Drug resistance -- Periodicals; Drug Resistance, Microbial -- Periodicals; 616.9041
• DOI: 10.1186/s13756-016-0151-2
• Languages: English
• ISSNs: 2047-2994

Abstract

Abstract Background Serotype K1Klebsiella pneumoniae has emerged as an important community pathogen causing various infections, including liver abscesses. Although serotype K1K. pneumoniae community isolates have been reported as susceptible to most classes of antimicrobial agents, a few cases of infection caused by extended-spectrum beta-lactamase (ESBL)-producing serotype K1K. pneumoniae have recently been reported in Asian countries. We identified three ESBL-producing strains of serotype K1K. pneumoniae and conducted a molecular characterization of their drug resistance. Methods Three ESBL-producing serotype K1K. pneumoniae ST23 strains were identified from strains in the Asian Bacterial Bank. Antimicrobial susceptibility testing was performed using the broth microdilution method, and ESBL production was tested by the double-disk synergy test and a confirmatory test. PCR was performed to detect the genes for plasmid-mediated ESBL and AmpC beta-lactamases. Results All three strains were resistant to cefotaxime, ceftazidime, and piperacillin/tazobactam, and all were determined to be ESBL-producers. No known ESBL genes, includingbla SHV, bla TEM, bla CTX-M, bla GES, bla PER, andbla VEB, were detected among the three strains. Of all plasmid-mediated AmpC beta-lactamase (PAB) genes, includingbla DHA-1, bla CMY, bla FOX, andbla MOX, thebla DHA-1 gene was detected in two of the strains. The PFGE patterns revealed that the two isolates carryingbla DHA-1 were closely related (84% similarity). Conclusions No ESBL genes were detected among three ESBL-producing serotype K1K. pneumoniae ST23 strains. Two strains contained the PAB genebla DHA-1 . The emergence of resistant strains of community-origin serotype K1K. pneumoniae has important implications for effective treatment and infection control practices.