TY - JOUR
T1 - Molecular characteristics of extended-spectrum β-lactamase-producing Klebsiella pneumoniae in Japan
T2 - Predominance of CTX-M-15 and emergence of hypervirulent clones
AU - Kakuta, Naoki
AU - Nakano, Ryuichi
AU - Nakano, Akiyo
AU - Suzuki, Yuki
AU - Masui, Takashi
AU - Horiuchi, Saori
AU - Kakuta, Risako
AU - Tsubaki, Kohsuke
AU - Ogawa, Miho
AU - Yano, Hisakazu
N1 - Funding Information:
This study was supported by JSPS KAKENHI (grant number: 17K10027 and 16K09940) . The funders had no role in study design, data collection and interpretation, the decision to publish, or preparation of this manuscript.
Publisher Copyright:
© 2020 The Authors
PY - 2020/9
Y1 - 2020/9
N2 - Objective: To provide data on the molecular characteristics of extended-spectrum β-lactamase (ESBL)-producing Klebsiella pneumoniae clinical isolates in Japan. Methods: A total of 100 clinical isolates of ESBL-producing K. pneumoniae collected throughout Japan between June and July 2018 were studied. ESBL genes were analyzed using PCR and DNA sequencing. Transferability of ESBL genes was investigated by conjugation experiments. Plasmid replicon types, virulence genes (rmpA, rmpA2, iucA, iroB, and peg-344) associated with hypervirulent K. pneumoniae (hvKp), and capsule types were detected using PCR. Genotyping was performed using multilocus sequence typing. Results: All ESBL-producing isolates carried blaCTX-M genes. The most predominant CTX-M-type identified was CTX-M-15 (n = 55). We identified 24 sequence types (STs) among the CTX-M-15 producers, with ST25 (n = 8) being the most common. Most of the transconjugants carrying blaCTX-M-15 contained the FIIk replicon. Of the 100 ESBL-producing isolates, 31 were hvKp defined by the presence of the virulence genes. These ESBL-producing hvKp isolates belonged to eight STs (STs 23, 25, 36, 65, 86, 268, 412, and 4492), with five capsule types (K1, K2, K20, K57, and undefined). Conclusions: CTX-M-15 was the predominant ESBL among K. pneumoniae isolates from Japan. This study shows that ESBL-producing hvKp strains comprising various clones are emerging in Japan.
AB - Objective: To provide data on the molecular characteristics of extended-spectrum β-lactamase (ESBL)-producing Klebsiella pneumoniae clinical isolates in Japan. Methods: A total of 100 clinical isolates of ESBL-producing K. pneumoniae collected throughout Japan between June and July 2018 were studied. ESBL genes were analyzed using PCR and DNA sequencing. Transferability of ESBL genes was investigated by conjugation experiments. Plasmid replicon types, virulence genes (rmpA, rmpA2, iucA, iroB, and peg-344) associated with hypervirulent K. pneumoniae (hvKp), and capsule types were detected using PCR. Genotyping was performed using multilocus sequence typing. Results: All ESBL-producing isolates carried blaCTX-M genes. The most predominant CTX-M-type identified was CTX-M-15 (n = 55). We identified 24 sequence types (STs) among the CTX-M-15 producers, with ST25 (n = 8) being the most common. Most of the transconjugants carrying blaCTX-M-15 contained the FIIk replicon. Of the 100 ESBL-producing isolates, 31 were hvKp defined by the presence of the virulence genes. These ESBL-producing hvKp isolates belonged to eight STs (STs 23, 25, 36, 65, 86, 268, 412, and 4492), with five capsule types (K1, K2, K20, K57, and undefined). Conclusions: CTX-M-15 was the predominant ESBL among K. pneumoniae isolates from Japan. This study shows that ESBL-producing hvKp strains comprising various clones are emerging in Japan.
KW - CTX-M-15
KW - Extended-spectrum β-lactamase
KW - Hypervirulent
KW - Klebsiella pneumoniae
UR - http://www.scopus.com/inward/record.url?scp=85088653492&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85088653492&partnerID=8YFLogxK
U2 - 10.1016/j.ijid.2020.06.083
DO - 10.1016/j.ijid.2020.06.083
M3 - Article
C2 - 32619765
AN - SCOPUS:85088653492
SN - 1201-9712
VL - 98
SP - 281
EP - 286
JO - International Journal of Infectious Diseases
JF - International Journal of Infectious Diseases
ER -
