摘要

在这里，我们报告了由含有CfiA4金属-β-内酰胺酶和上游插入序列（IS）元件的脆弱拟杆菌菌株引起的腹腔内感染引起的致命败血症的病例。美罗培南作为经腹腔感染的结果用于脓毒性休克的经验性治疗，尽管之前已经进行了两轮碳青霉烯治疗。感染性休克发病4天后，从两个厌氧血培养瓶中分离出脆弱拟杆菌。药敏试验表明，除甲硝唑和替加环素外，该分离株对所有受试药物均不敏感。该分离物在乙二胺四乙酸和碳青霉烯灭活试验中给出阳性结果，但在使用巯基乙酸钠的双盘协同试验中呈阴性结果。下一代全基因组测序表明存在cfiA4，emrG和emrF基因。 PCR表明在cifA4基因上游存在IS元件。虽然碳青霉烯抗性脆弱分枝杆菌菌株先前已有报道，但该生物体的临床败血症被认为是罕见的。在日本，与全球大多数国家一样，常规药敏试验和金属-β-内酰胺酶的检测不在厌氧生物中进行，包括脆弱拟杆菌。应监测治疗期间碳青霉烯耐药性的出现，因为含有cfiA基因的脆弱类杆菌菌株在碳青霉烯疗法期间显示出降低的敏感性。因此，在厌氧细菌感染的情况下，需要进行药敏试验和适当的抗生素管理。

Here, we report a case of fatal sepsis resulting from an intra-abdominal infection caused by a Bacteroides fragilis strain containing a CfiA4 metallo-β-lactamase and an upstream insertion sequence (IS) element. Meropenem was used as empiric therapy for septic shock as a result of the intra-abdominal infection, although two rounds ofcarbapenem treatment had been administered previously. B. fragilis was isolated from two anaerobic blood culture bottles 4 days after the onset of septic shock. Susceptibility testing revealed that the isolate was non-susceptible to all tested agents except metronidazole and tigecycline. The isolate gave a positive result inethylenediaminetetraacetic acid and carbapenem inactivation tests, but a negative result in a double-disk synergy test using sodium mercaptoacetate. Next-generationwhole-genome sequencing indicated the presence of the cfiA4, emrG and emrFgenes. PCR indicated the presence of an IS element upstream of the cifA4 gene. Although carbapenem-resistant B. fragilis isolates have previously been reported, clinical sepsis by this organism is considered rare. In Japan, as in most countries worldwide, routine susceptibility testing and the detection of metallo-β-lactamases is not carried out in anaerobic organisms, including B. fragilis. The emergence of carbapenem resistance during therapy should be monitored, as B. fragilis strains containing the cfiA gene show decreased sensitivity during carbapenem therapy. Therefore, susceptibility testing and appropriate antibiotic stewardship are required in cases of anaerobic bacterial infections.

https://www.sciencedirect.com/science/article/pii/S1075996417300185