Comparative genetic analysis of the antimicrobial susceptibilities and virulence of hypermucoviscous and non-hypermucoviscous ESBL-producing Klebsiella pneumoniae in Japan

Hiroshi Tanimoto, Katsumi Shigemura, Kayo Osawa, Mitsuki Kado, Reo Onishi, Shiuh Bin Fang, Shian Ying Sung, Takayuki Miyara, Masato Fujisawa

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)

Abstract

Background: Hypermucoviscous (HMV) Klebsiella pneumoniae produces large amounts of capsular polysaccharides, leading to high mortality. Since extended spectrum beta-lactamase (ESBL)-producing HMV K. pneumoniae strains have increased in Japan, we investigated and compared the antimicrobial susceptibilities and genetic characteristics of HMV and non-HMV ESBL-producing K. pneumoniae. Methods: We investigated 291 ESBL-producing K. pneumoniae collected between 2012 and 2018, and in them 54 HMV strains were identified and comparable 53 non-HMV strains were selected. Then, ESBL gene detection, plasmid replicon typing, and virulence gene detection were done by PCR amplification. Results: Almost all of the HMV K. pneumoniae strains possessed uge (98.1%), wabG (96.3%), rmpA (94.4%), iucA (79.6%), fimH (70.4%), iroB (70.4%), and peg-344 (70.4%). These genes were found less frequently in non-HMV strains (uge 20.8%, wabG 83.0%, rmpA 7.5%, iucA 3.8%, fimH 9.4%, iroB 5.7%, and peg-344 1.9%). K2 capsule type (40.7%) was most common in HMV strains. HMV strains showed higher resistance to cefepime (p = 0.001) and piperacillin/tazobactam (p = 0.005) than non-HMV strains. CTX-M-15 (75.9%, 60.4%) was the dominant ESBL type in both HMV and non-HMV strains, and the most common plasmid replicon type was IncFII (52.1%) in CTX-M-15-producing strains. Conclusions: We found that HMV strains had more virulence genes and showed higher resistance to antibiotics than non-HMV strains. The most common capsule type was K2. CTX-M-15 was the most common type of ESBL gene in both HMV and non-HMV strains in Japan. The FII plasmid might be related to the spread of CTX-M-15 among K. pneumoniae strains.

Original languageEnglish
Pages (from-to)93-103
Number of pages11
JournalJournal of Microbiology, Immunology and Infection
Volume56
Issue number1
DOIs
Publication statusPublished - Feb 2023

Keywords

  • CTX-M-15
  • Extended spectrum beta-lactamase (ESBL)
  • Hypermucoviscous (HMV) Klebsiella pneumoniae
  • Hypervirulence in K. pneumoniae (hvKp)
  • Plasmid

ASJC Scopus subject areas

  • Immunology and Allergy
  • General Immunology and Microbiology
  • Microbiology (medical)
  • Infectious Diseases

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