摘要:
Objective To investigate the biofilm formation rate of Candida albicans strain and its sensitivity to antifungal agents.Methods Candida albicans strains were isolated from 165 patients with vulvovaginal candidiasis (VVC) or recurrent vulvovaginal candidiasis (RVVC) in our hospital.The sensitivity of C.albicans strains to antifungal agents was evaluated by drug sensitivity test.And C54 strains for subsequent experiments in vivo and vitro were selected.Biofilms of single microbe or polymicrobial combination were induced in vitro,and their minimal inhibitory concentration (MIC) values were determined in free and biofilm patterns,respectively.C.albicans and mixed microbe suspensions were injected into mice to establish a model of VVC.Using ELIASA,OD595 values were determined to observe biofilm growth rates across groups.Results The largest number of itraconazole-resistant on C.albicans strains (4.20%).MIC values of all groups were higher in a free pattern than in a biofilm pattern.The polymicrobial biofilms formed by co-culture of fugal and bacterial strains were markedly resistant to various antifungal agents.Mter induction in the biofilm pattern,for C54 + Escherichia coli group,MIC values of resistance to amphotericin B,itraconazole,5-flucytosine and fluconazole were 512,>256,>512,and > 1024 μg · mL-1;for C54 + Streptococcus agalactiae group,MIC values of resistance to above antifungal agents were >512,>256,>512,and > 1024 μg · mL-1.The biofilm formation rate was significantly higher in vaginal samples isolated from the mice who were injected with mixed microbe suspension than those who were injected with standard C.albicans suspension (P < 0.05).For ATCC14053 group,OD595 values were 0.20 ± 0.11,0.24 ± 0.024,0.25 ± 0.06 at 24,48 and 72 h,respectively;for C54 + E.coli group,OD595 values were 0.69 ±0.88,0.79 ±0.65,1.10 ±0.64 respectively;for C54 +S.agalactiae group,OD595 values were 0.68 ±0.42,0.81 ± 0.77,1.10 ± 0.10,respectively.Conclusion Polymicrobial biofilm formation can improve the biofilm formation rate of C.albicans and its resistance to antifungal agents and will enhance vaginal injury in patients with RVVC.%目的 研究白色念珠菌菌株的生物膜形成率及其对抗真菌剂的敏感性.方法 收集本院165例从外阴阴道假丝酵母菌病(VVC)或复发性外阴阴道假丝酵母菌病(RVVC)患者分离的白色念珠菌菌株,以药敏实验评估白色念珠菌株的抗真菌药物敏感性.选取菌株C54用于体内外实验:体外诱导单生菌或多微生物组合的生物膜,并测定其在游离和生物膜形式下的最低抑菌浓度(MIC)值.小鼠体内注射白色念珠菌或混合微生物悬浮液构建WC模型,用酶联免疫印迹法检测0D595值来观察各组生物膜生长速率.结果 对伊曲康唑耐药的白色念珠菌菌株最多,占总数的4.20%.各组生物膜形式的MIC值均高于其游离形式,真菌和细菌菌株的共培养所形成的多微生物生物膜对各种抗真菌药物具有明显的耐药性,经诱导后在生物膜形式下,C54+大肠杆菌组对两性霉素B、伊曲康唑、5-氟胞嘧啶和氟康唑的MIC值为512,>256,>512,>1024μg·mL-1;C54+无乳链球菌组对上述抗真菌药物的MIC为>512,>256,>512,>1024 μg·mL-1.从注射混合微生物悬浮液的小鼠分离的阴道样品中,生物膜形成速率显著高于注射标准白色念珠菌悬浮液的小鼠,差异有统计学意义(P<0.05).在24,48,72 h,ATCC14053组的OD595值分别为0.20±0.11,0.24±0.024,0.25±0.06;C54+大肠杆菌组的OD595值分别为0.69±0.88,0.79±0.65,1.10±0.64;C54+无乳链球菌组的OD595值分别为0.68±0.42,0.81±0.77,1.10 ±0.10.结论 多微生物生物膜的形成能提高白色念珠菌的生物膜形成速率和抗真菌剂耐药性,这将增强对RVVC患者的阴道损伤.