Epidemiological analysis and antimicrobial susceptibility profile of Gram-negative bacilli that cause bacteremia in Japan

Kosuke Kosai; Yuka Yamagishi; Hiroshige Mikamo; Yoshikazu Ishii; Kazuhiro Tateda; Katsunori Yanagihara

doi:10.1016/j.jiac.2023.08.012

Epidemiological analysis and antimicrobial susceptibility profile of Gram-negative bacilli that cause bacteremia in Japan

J Infect Chemother. 2023 Dec;29(12):1091-1096. doi: 10.1016/j.jiac.2023.08.012. Epub 2023 Aug 18.

Authors

Kosuke Kosai¹, Yuka Yamagishi², Hiroshige Mikamo³, Yoshikazu Ishii⁴, Kazuhiro Tateda⁴, Katsunori Yanagihara⁵

Affiliations

¹ Department of Laboratory Medicine, Nagasaki University Hospital, Nagasaki, Japan. Electronic address: k-kosai@nagasaki-u.ac.jp.
² Department of Clinical Infectious Diseases, Aichi Medical University, Aichi, Japan; Department of Clinical Infectious Diseases, Kochi Medical School, Kochi University, Kochi, Japan.
³ Department of Clinical Infectious Diseases, Aichi Medical University, Aichi, Japan.
⁴ Department of Microbiology and Infectious Diseases, Toho University School of Medicine, Tokyo, Japan.
⁵ Department of Laboratory Medicine, Nagasaki University Hospital, Nagasaki, Japan.

PMID: 37597749
DOI: 10.1016/j.jiac.2023.08.012

Abstract

We investigated the epidemiology and antimicrobial susceptibility profiles of seven major Gram-negative bacilli (Escherichia coli, Klebsiella spp., Enterobacter spp., Pseudomonas aeruginosa, Acinetobacter spp., Stenotrophomonas maltophilia, and Bacteroides spp.) that caused bacteremia in Japan. We collected clinical information and isolates from patients aged 20 years or older who developed bacteremia during a year at three Japanese university hospitals and performed microbiological examination. In total, 628 cases were included, half of which were caused by E. coli (315 isolates). P. aeruginosa (56 isolates) was isolated most frequently among non-fermenting bacteria and 33 Bacteroides spp. were isolated. Mortality rates were the highest for P. aeruginosa (7-day, 16.1%; 30-day, 26.8%). The 7- and 30-day mortality rates ranged 3.8-9.0% and 8.3-17.6%, respectively, for Enterobacterales, and they were 15.2% each for Bacteroides spp. Regarding antimicrobial resistance, Enterobacterales and Acinetobacter spp. showed susceptibility to carbapenems and amikacin (98.0-100.0%). The susceptibility rates to ceftolozane/tazobactam ranged 82.4-99.0% for Enterobacterales and 92.9% for P. aeruginosa. More than 30.0% of E. coli isolates were resistant to fluoroquinolone. Extended-spectrum β-lactamase (ESBL) producers were found in 21.0% of E. coli and approximately 80% of those were resistant to fluoroquinolones. The susceptibility of the 33 Bacteroides spp. to carbapenems, ampicillin/sulbactam, and piperacillin/tazobactam was 100.0%. Among the ESBL producers, bla_CTX-M group 9 was the major subgroup in E. coli (77.3%), and bla_CTX-M group 1 was detected in 18.2% of E. coli and 50.0% of Klebsiella spp. Continuous surveillance is needed to understand the epidemiology and consider appropriate therapeutic strategies.

Keywords: Antimicrobial resistance; Bacteremia; Surveillance.

Copyright © 2023 Japanese Society of Chemotherapy, Japanese Association for Infectious Diseases, and Japanese Society for Infection Prevention and Control. Published by Elsevier Ltd. All rights reserved.