Antimicrobial susceptibility and prevalence of resistance genes in Bacteroides fragilis isolated from blood culture bottles in two tertiary care hospitals in Japan. (August 2020)

• Record Type: Journal Article
• Authors: Ogane, Kana; Tarumoto, Norihito; Kodana, Masahiro; Onodera, Azusa; Imai, Kazuo; Sakai, Jun; Kawamura, Toru; Takeuchi, Shinichi; Murakami, Takashi; Mitsutake, Kotaro; Ikebuchi, Kenji; Maesaki, Shigefumi; Maeda, Takuya
• Is Part Of: Anaerobe. Volume 64(2020)
• Publication Date: 2020-08
• Subjects: Bacteroides fragilis -- Antimicrobial resistance -- cfiA -- Insertion sequence; Anaerobic infections -- Periodicals; Anaerobic bacteria -- Periodicals; Bacterial diseases -- Periodicals; Computer network resources; Anaerobic protozoa -- Periodicals; 579.3
• DOI: 10.1016/j.anaerobe.2020.102215
• Languages: English
• ISSNs: 1075-9964

Abstract

Abstract: The in vitro susceptibilities of Bacteroides fragilis to antimicrobial agents, especially to carbapenem, are a major concern in the treatment of patients with bloodstream infections. In this study, 50 isolates of B. fragilis were obtained from positive blood bottles from 2014 to 2019 in Saitama, Japan. Their susceptibility to ampicillin/sulbactam was reduced to 70.0% compared with a previous report, whereas they were still sufficiently susceptible to piperacillin/tazobactam (94.0%). Five cfiA -positive isolates (5/50, 10.0%) were identified that were resistant to doripenem and meropenem, and two of them carried an insertion sequence located upstream of the cfiA -coding region. In particular, imipenem should be considered as a first-line carbapenem for the empirical treatment of B. fragilis infection because only insertion sequence and cfiA double-positive strains showed resistance to imipenem. Thirty-six percent of the isolates had a reduced minimum inhibitory concentration for moxifloxacin. In addition, metronidazole should still be considered as an active agent for B. fragilis because all isolates were susceptible to this antibiotic and the prevalence of the nim gene was low in Japan. Highlights: The cfiA gene was detected in 10.0% of Bacteroides fragilis isolates. Insertion sequence was detected in 2 out of 5 isolates harboring the cfiA gene. Double-positive strains of insertion sequence and cfiA showed resistance to imipenem. No strain resistant to metronidazole was detected.