痤疮丙酸杆菌对抗菌药物的体外抗菌活性分析

Analysis of antibacterial activity of Propionibacterium acnes against antimicrobial agents in vitro

目的研究外伤后细菌性致死性肉芽肿(FBGT)病原菌的培养分离方法并了解常用抗菌药的体外抗菌活性,为该病的诊断和治疗提供实验室依据。方法采用改良兔脑厌氧增菌肉汤(RRNB)、厌氧琼脂平板置厌氧环境培养,用API鉴定系统20A鉴定板鉴定病原菌;采用肉汤稀释法测定最低抑菌浓度(MIC)。结果从13例FBGT患者中应用RRNB培养基分离到14株病原菌,经ATB/API细菌鉴定系统20A检测,确定为痤疮丙酸杆菌。该菌严格厌氧,培养初期生长极为缓慢,在RRNB中生长良好,但需1～2周时间。环丙沙星对14株病原菌的MIC值均在0.0625～0.5mg/L,青霉素、氨苄西林、氨苄西林/舒巴坦、头孢哌酮、林可霉素、亚安培南/西司他丁的MIC值均在0.125～0.5mg/L,替卡西林/克拉维酸的MIC值为0.25～1.0mg/L,甲硝唑的MIC值为64.0～256.0mg/L。结论 FBGT的病原菌为痤疮丙酸杆菌,该菌对甲硝唑耐药,临床不能用该类药物治疗;青霉素、氨苄西林、林可霉素等常用抗菌药物体外抗菌活性均较高,临床可选择不同种类的抗菌药物联合应用,并与其他疗法联合治疗FBGT。

Objective To investigate the isolation and culture method of pathogens of a rare disease-fatal bacteria granuloma after trauma （FBGT）,and antibacterial activity of routine antimicrobial agents in vitro in order to found a basis for the diagnosis and treatment of FBGT.Methods The FBGT pathogens were isolated and cultured by reformed rabbit-brain anaerobic enriched broth （RRNB）,and identified by API 20A system.The minimum inhibiting concentration （MIC） was determined by anaerobic broth dilution method.Results Fourteen strains of bacteria were isolated from thirteen patients with FBGT and identified as Propionibacterium acnes （PA） by ATB/API 20A system.The pathogens of FBGT were strictly anaerobic,and they grew slowly in nutritious RRAB,and 1-2 weeks may be necessary to isolate successfully.The MIC of 14 strains of PA against Ciprofloxacin was 0.0625-0.5mg/L,the MIC of Penicillin,Ampicillin,Ampicillin/sulbactam,Cefoperazone,Lincomycin,Imipenem/cilastatin was 0.125-0.5mg/L,and the MIC of Ticarcillin/clavulanic acid was 0.125～0.5mg/L,but that of Metronidazole was 64.0-256.0mg/L.Conclusions All the isolated PA strains are resistant to Metronidazole,but susceptible to the other commonly used antimicrobial agents,such as Penicillin,Ampicillin and Lincomycin.Therefore,FBGT should not be treated with metronidazole,but a combined use of antibiotics should be recommended.