Roscoe D L, Zemcov S J, Thornber D, Wise R, Clarke A M
Division of Medical Microbiology, St. Paul's Hospital, Vancouver, British Columbia, Canada.
Antimicrob Agents Chemother. 1992 Oct;36(10):2197-200. doi: 10.1128/AAC.36.10.2197.
Capnocytophaga species have been associated with a wide variety of infections in both immunocompetent and immunocompromised patients. On the basis of data from antimicrobial susceptibility studies, beta-lactam antibiotics have been considered efficacious therapy. Six of 19 isolates from primarily clinical sources across Canada demonstrated beta-lactamase production, and agar dilution susceptibility testing showed broad resistance to beta-lactam antibiotics. For the beta-lactamase producing isolates, clavulanate reduced the MIC of amoxicillin for 90% of the strains tested by 64-fold. Isolates were highly susceptible to clindamycin, imipenem, and ciprofloxacin. Characterization of the beta-lactamases produced by two of these isolates (Van1 and Van2) was performed. Isoelectric focusing revealed an identical isoelectric point of 5.6 for both enzymes, but they had markedly different relative hydrolysis efficiencies, and different conditions were required to extract the enzymes. This study demonstrates the production of different types of beta-lactamases by Capnocytophaga spp. and suggests the need to screen all clinical isolates of Capnocytophaga spp. for the presence of beta-lactamases.
二氧化碳嗜纤维菌属菌种与免疫功能正常和免疫功能低下患者的多种感染有关。根据抗菌药物敏感性研究数据，β-内酰胺类抗生素被认为是有效的治疗药物。在加拿大各地主要临床来源的19株分离菌中，有6株显示产β-内酰胺酶，琼脂稀释药敏试验表明对β-内酰胺类抗生素具有广泛耐药性。对于产β-内酰胺酶的分离菌，克拉维酸使90%受试菌株的阿莫西林最低抑菌浓度降低了64倍。分离菌对克林霉素、亚胺培南和环丙沙星高度敏感。对其中两株分离菌（Van1和Van2）产生的β-内酰胺酶进行了特性分析。等电聚焦显示两种酶的等电点相同，均为5.6，但它们的相对水解效率明显不同，提取酶所需的条件也不同。本研究证明二氧化碳嗜纤维菌属菌种可产生不同类型的β-内酰胺酶，并表明有必要对所有二氧化碳嗜纤维菌属临床分离菌进行β-内酰胺酶检测。
