4种抗真菌药物对近平滑念珠菌复合群的体外药敏试验结果分析

Analysis of in Vitro Antifungal Susceptibility Testing of Four Antifungal Drugs to Candida Parapsilosis Complex

目的:评价4种抗真菌药物对近平滑念珠菌复合群的抗真菌体外药物敏感性试验结果,为临床治疗、真菌耐药监测和流行病学研究提供参考。方法:收集2020年1月~2022年7月期间本院278例侵袭性真菌感染患者临床分离的非重复近平滑念珠菌复合群278株,并采用分子测序技术进行复核。根据美国临床实验室标准化协会(CLSI)更新的M59和M60指南,通过ATB FUNGUS3法测定两性霉素B、伏立康唑、氟康唑和伊曲康唑的最低抑菌浓度(MIC),并计算抑制50%菌株的MIC值(MIC_(50))、抑制90%菌株的MIC值(MIC_(90))、MIC值几何均数(GM)、野生型(WT)菌株或敏感菌株占比。结果:278株受试菌株中,近平滑念珠菌213株(76.62%),似平滑念珠菌43株(15.47%),拟平滑念珠菌22株(7.91%);病原菌主要分离自创面分泌物(85株,30.58%),且在66岁以上人群中更为常见(128例,46.04%);患者主要分布于外科病区(89例,32.01%)、内科病区(79例,28.42%)和ICU病区(77例,27.70%)。在复合群水平上,对氟康唑耐药的有16株(5.76%),剂量依赖性敏感的有6株(2.16%);伊曲康唑的非野生型(NWT)菌株4株(1.44%);对伏立康唑耐药的有9株(3.24%),中介的有7株(2.52%);所有菌株均为两性霉素B的WT菌株(100.00%)。在种水平上,所有菌株均为两性霉素B的WT菌株(100.00%);伊曲康唑对3种菌均表现出较好的抑菌活性,95%以上菌株均为伊曲康唑WT菌株(P>0.05)。近平滑念珠菌中,MIC_(90)为2μg/ml,199株(93.43%)为氟康唑敏感株;似平滑念珠菌中,MIC_(90)为2μg/ml,42株(97.67%)为氟康唑WT菌株;拟平滑念珠菌中,MIC_(90)为16μg/ml,15株(68.18%)为氟康唑WT菌株,与其他两种菌比较有统计学差异(P<0.05);拟平滑念珠菌与其他两种菌相比,其氟康唑NWT菌株分离率最高(7株,31.82%)。伏立康唑对近平滑念珠菌和似平滑念珠菌MIC_(90)均为0.06μg/ml,GM分别为0.0688、0.0672μg/ml,204株(95.77%)近平滑念珠菌为敏感株,42株(97.67%)似平滑念珠菌为WT菌株;拟平滑念珠菌的MIC_(90)为0.5μg/ml,GM为0.1213μg/ml,GM与其他两种菌比较有统计学差异(P<0.05),仅16株(72.73%)为WT菌株,与其他两种菌比较有统计学差异(P<0.05)。结论:两性霉素B和伊曲康唑对近平滑复合群内3种念珠菌均表现出较强的抗菌活性,氟康唑和伏立康唑的抗菌活性则存在种间差异,表现为二者对拟平滑念珠菌的抗菌活性较差。因此,临床需重视真菌监测和菌株的准确鉴定,合理应用抗菌药物,同时需警惕耐药情况的发生。

Objective:To evaluate the results of in vitro antifungal susceptibility test of four antifungal agents against Candida parapsilosis complex,so as to provide reference for clinical treatment,fungal resistance monitoring and epidemiological research.Method:278 non-repetitive Candida parapsilosis complex strains isolated from 278 patients with invasive fungal infection in our hospital were collected from January2020 to July 2022 and reconfirmed by molecular sequencing technology.Updated M59 and M60 guidelines according to the Clinical and Laboratory Standards Institute,the minimum inhibitory concentrations(MIC)of amphotericin B,voriconazole,fluconazole and itraconazole was determined by the ATB FUNGUS 3method.The MIC value which 50%of the strains was inhibited(MIC_(50)),MIC value which 90%of the strains was inhibited(MIC_(90)),the geometric mean(GM)of MIC,the wild-type(WT)strain or the proportion of susceptible strains were also calculated.Results:Among the 278 tested strains,C.parapsilosis was 213(76.62%),C.metapsilosis was 43(15.47%),C.orthopsilosis was 22(7.91%).Pathogenic bacteria were mainly isolated from wound secretion samples(85cases,30.58%),and they were more common among people over66 years old(128 cases,46.04%).The patients were mainly distributed in surgical wards(89 cases,32.01%),medical wards(79 cases,28.42%)and ICU wards(77 cases,27.70%).At the complex level,16 strains were fluconazole resistant(5.76%),6 strains were dose-dependent sensitive(2.16%);4 strains were NWT to itraconazole(1.44%),9 strains were resistant to voriconazole(3.24%),7 strains were intermediate(2.52%).All strains were WT strains of amphotericin B(100.00%).At the species level,all strains were WT strains of amphotericin B(100.00%).Itraconazole showed good antifungal activity against the three strains,and more than 95%of the strains were WT strains(P>0.05).In C.parapsilosis,MIC_(90) was 2μg/ml,199 strains(93.43%)were sensitive to fluconazole.In C.metapsilosis,MIC_(90) was 2μg/ml,42 strains(97.67%)were WT strains to itraconazole.In C.orthopsilosis,MIC_(90) was 16μg/ml,15 strains(68.18%)were WT strains.Compared with other two kinds of bacteria,there were statistical differences(P<0.05).Compared with the other two strains,the highest rate of NWT was observed in C.orthopsilosis to fluconazole(7 cases,31.82%).The MIC_(90) of voriconazole against C.parapsilosis and C.metapsilosis was 0.06μg/ml,GM was 0.0688μg/ml and 0.0672μg/ml respectively,204 strains(95.77%)of C.parapsilosis were sensitive to voriconazole,and 42strains(97.67%)of C.metapsilosis were WT to voriconazole,MIC_(90) for C.orthopsilosis was 0.5μg/ml,GM was 0.1213μg/ml,GM value was statistically different from the other two strains(P<0.05).Only 16 strains(72.73%)were WT strains,which was statistically different from the other two strains(P<0.05).Conclusion:The three Candida species showed strong in vitro activities against amphotericin B and itraconazole,but showed inter species diff erences in the in vitro activities against fluconazole and voriconazole.The in vitro activity of C.orthopsilosis to fluconazole and voriconazole was lower than that of C.parapsilosis and C.metapsilosis.Therefore,clinical attention should be paid to fungal monitoring and accurate identification of strains,rational use of antibiotics,and vigilance against the occurrence of drug resistance at the same time.