Antimicrobial resistance profiles and resistance mechanisms in clinical Prevotellaceae and Fusobacteriaceae isolates from a tertiary care center
Anaerobe, cilt.99, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 99
- Basım Tarihi: 2026
- Doi Numarası: 10.1016/j.anaerobe.2026.103062
- Dergi Adı: Anaerobe
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, BIOSIS, EMBASE, MEDLINE, Academic Search Ultimate (EBSCO)
- Anahtar Kelimeler: Antimicrobial resistance, Fusobacterium, nimK, Prevotella, Segatella
- Hacettepe Üniversitesi Adresli: Evet
Özet
Background: Species of the families Prevotellaceae and Fusobacteriaceae are frequently involved in endogenous and polymicrobial infections. Increasing antimicrobial resistance among anaerobic bacteria highlights the importance of local surveillance studies and resistance mechanism analysis. This study aimed to evaluate antimicrobial susceptibility profiles and selected resistance determinants among clinical Prevotellaceae and Fusobacteriaceae isolates recovered at a tertiary care center. Methods: A total of 110 anaerobic gram-negative isolates, including 76 Prevotellaceae and 34 Fusobacteriaceae isolates, recovered between July 2018 and June 2022, were included. Species identification was performed using MALDI-TOF MS. Antimicrobial susceptibility testing (AST) for ampicillin, piperacillin–tazobactam, cefoxitin, meropenem, clindamycin, metronidazole, and tigecycline was performed by agar dilution according to CLSI recommendations. β-lactamase production was evaluated using nitrocefin disks. The presence of cfxA, ermF, tetQ, and nim genes was investigated by real-time PCR. Results: Piperacillin–tazobactam, meropenem, metronidazole, and tigecycline showed high in vitro activity against all isolates. Prevotella spp. showed high resistance rates to ampicillin (78.9%) and clindamycin (57.9%), while resistance rates among Segatella spp. were 58.6% and 44.8%, respectively. Fusobacterium spp. demonstrated low ampicillin resistance (8.9%), and no clindamycin resistance was detected. Clindamycin resistance was identified in four Hoylesella isolates, whereas ampicillin resistance was observed in two Hoylesella isolates and one Hallella bergensis isolate. β-lactamase production was detected in 76.3% of Prevotella spp., 51.7% of Segatella spp., and 8.9% of Fusobacterium spp. isolates. The cfxA, ermF, and tetQ genes were detected in 86.8%, 71.1%, and 60.5% of Prevotella spp.; 51.7%, 58.6%, and 27.6% of Segatella spp.; and 8.9%, 5.9%, and 11.8% of Fusobacterium spp. isolates, respectively. The nimK gene was identified in two Prevotella bivia isolates without phenotypic metronidazole resistance. Conclusions: Marked differences in antimicrobial susceptibility profiles were observed between Prevotellaceae and Fusobacteriaceae isolates. Prevotellaceae isolates demonstrated substantial resistance to ampicillin and clindamycin and frequently harbored transferable resistance determinants, whereas Fusobacterium spp. largely retained susceptibility to commonly used anti-anaerobic agents. Continuous surveillance of anaerobic bacteria remains important, particularly given ongoing taxonomic revisions within the Prevotellaceae family.