2种培养基对临床粪便标本中艰难梭菌分离培养的比较研究

Comparative study of two media for the isolation and culture of Clostridium difficile from faecal speciments

目的用CDIF与厌氧血琼脂平皿2种培养基,对临床粪便标本中艰难梭菌（Clostridium difficile,CD）的分离培养情况进行比较和研究,为临床CD培养与诊断提供依据。方法采集长期住院患者的粪便标本60份,分别接种CDIF与厌氧血琼脂平皿,挑取平皿上的可疑菌落,用MALDI-TOF-MS方法进行鉴定,并对检出的CD进行16S rRNA基因测序验证,计算2种培养方法的灵敏度、特异度、约登指数。结果 CDIF和厌氧血琼脂平皿的CD检出率分别为30.0%和26.7%,差异无统计学意义（χ^2=0.164,P=0.685）。CDIF平皿的灵敏度为90%,特异度为100%,约登指数为0.9;厌氧血琼脂灵敏度为80%,特异度为100%,约登指数为0.8。CDIF上仅检出4种厌氧菌,而厌氧血琼脂平皿共检出14种细菌,检出的菌种分布差异有统计学意义（χ^2=19.161,P=0.045）。结论 CDIF的真实性和筛检价值高于普通厌氧血琼脂平皿。

Objective To compare and study the isolation and culture of Clostridium difficile（ CD） from clinical faecal specimens with CDIF agar and anaerobic blood agar,so as to provide evidence for CD culture and diagnosis. Methods A total of 60 fresh faecal specimens were collected from long-term hospitalized patients,and perform them on CDIF and anaerobic blood agar. The suspecious bacteria was gathered for identification with MALDI-TOF-MS,and the detected CDs were further confirmed by 16 s rRNA gene sequencing. Sensitivity,specificity and Youden＇s index of the two methods were calculated.Results The detection rates of CD with CDIF and anaerobic blood agar were 30. 0% and 26. 7%,respectively,with the difference not statistically significant（ χ2= 0. 164,P = 0. 685）. Sensitivity,specificity and Youden＇s index of CDIF were 90%,100% and 0. 9,while those of anaerobic blood agar were 80%,100% and 0. 8. Only four kinds of anaerobic bacteria were detected on CDIF,but fourteen kinds of bacteria were detected on anaerobic blood agar. There was statistical significance on the difference of bacteria distribution between the two media（ χ2= 19. 161,P = 0. 045）. Conclusion The validity and value of CDIF are higher than anaerobic blood agar.