Bacteremia implicating anaerobic bacteria (BIAB) represents 2–6% of all episodes of bacteremia and is associated with high mortality. In this retrospective study from June 2015 to December 2016, we compared BIAB frequency in two hospital centers in Montpellier (France): Montpellier university hospital (MUH) and a center specialized in cancer (ICM). Among the 2465 microbiologically relevant episodes of bacteremia, we identified 144 (5.8%) in which anaerobic bacteria were implicated. BIAB frequency was higher at ICM than MUH (10.4%, vs. 4.9%, p < 0.01). Poly-microbial bacteremia was more frequent among the BIAB episodes (31.9% vs. 11.0% for aerobic-only bacteremia, p < 0.01). Bacteroides and Clostridium were the most frequently identified genera of anaerobic bacteria (64 and 18 episodes, respectively), with the B. fragilis group (BFG) involved in 68/144 episodes. We could perform antibiotic susceptibility typing in 106 of the 144 anaerobic isolates, including 67 BFG isolates. All isolates but one were susceptible to metronidazole. In the BFG, sporadic resistant or intermediate results were found for amoxicillin-clavulanate (5/67), piperacillin-tazobactam (2/67) and imipenem (1/67). BFG isolates were susceptible also to cefoxitin (90.8%), rifampicin (97.0%) and tigecyclin (91.0%). Multidrug resistance in this group (7 isolates) was mostly due to acquired resistance to moxifloxacin, clindamycin and tigecyclin. This study shows that BIAB frequency can vary among hospitals and services. They should especially be taken into account in centers specialized in cancer treatment. However, the implicated bacteria remain frequently susceptible to the most used antibiotics used against anaerobic bacteria, although resistance does exist.

涉及厌氧菌的细菌血症（BIAB）占所有菌血症发作的2–6％，并与高死亡率相关。在2015年6月至2016年12月的这项回顾性研究中，我们比较了蒙彼利埃（法国）的两个医院中心（蒙彼利埃大学医院（MUH）和癌症专科中心（ICM））的BIAB频率。在2465种与微生物有关的菌血症发作中，我们确定了144种（5.8％）涉及厌氧菌。ICM的BIAB频率高于MUH（10.4％，而4.9％，p <0.01）。在BIAB发作中，多菌血症更为常见（31.9％比仅需氧菌血症为11.0％，p <0.01）。拟杆菌和梭菌是厌氧细菌（64和18集，分别地）的最经常识别的属，与脆弱拟杆菌组（BFG）参与68/144集。我们可以对144种厌氧菌中的106种进行抗生素敏感性分型，包括67种BFG菌。除一株外，其他所有菌株均对甲硝唑敏感。在高炉煤气中，发现阿莫西林-克拉维酸盐（5/67），哌拉西林-他唑巴坦（2/67）和亚胺培南（1/67）的散发耐药性或中间结果。BFG分离株也对头孢西丁（90.8％），利福平（97.0％）和替加环素（91.0％）敏感。该组（7个分离株）的多药耐药性主要归因于对莫西沙星，克林霉素和替加环素的获得性耐药。这项研究表明，BIAB的频率在医院和服务之间可能有所不同。在专门从事癌症治疗的中心应特别考虑到它们。然而，