南方医科大学学报 ›› 2017, Vol. 37 ›› Issue (12): 1648-.

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3种艰难梭菌感染检测方法的比较

王丽志,陈丽丹,肖斌,甘燕玲,李林海,王前   

  • 出版日期:2017-12-20 发布日期:2017-12-20

Efficacy of real- time PCR for detecting Clostridium difficile infection: comparison with enzyme-linked fluorescent spectroscopy-based approaches

  • Online:2017-12-20 Published:2017-12-20

摘要: 目的评价3种艰难梭菌感染(CDI)检测方法的诊断效能,为CDI寻找合适的诊断方案。方法收集中国人民解放军广州 总医院2016年5月~12月疑似CDI的腹泻患者粪便标本70例,采用3种方法进行检测:(1)培养法;(2)酶联荧光法检测艰难梭菌 毒素A/B(CDAB)和谷氨酸脱氢酶(GDH);(3)q-PCR扩增艰难梭菌特异性基因tpi和毒素基因(tcdA/tcdB)。以培养法的检测 结果作为参考标准,计算3 种方法的诊断指标。结果收集粪便样本70 例,分离艰难梭菌13 例(18.57%),其中产毒株6 例 (8.57%)。q-PCR法鉴定tpi基因阳性17例,其敏感度、特异度、阳性预测值、阴性预测值、诊断符合率分别为92.31%、91.23%、 70.59%、98.11%、91.43%,均高于GDH法(84.62%、84.21%、55.00%、96.00%、84.29%)(χ2=24.881,P<0.001),且q-PCR扩增tcdA/ tcdB的敏感度(66.67%)优于CDAB(33.33%)(χ2=35.918,P<0.001)。结论CDAB检测和q-PCR法特异性较高,GDH法具有较 好的灵敏度,3者均有较高的阴性预测值。与其他检测方法相比,q-PCR法检测CDI具有时效性强,灵敏度高,特异性好等优势, 适用于临床推广。

Abstract: Objective To evaluate the diagnostic efficacy of real-time polymerase chain reaction (q-PCR) for Clostridium difficile infection (CDI) in comparison with routine culture and enzyme-linked fluorescent spectroscopy-based aprroaches. Methods Stool samples were collected from suspected CDI cases in General Hospital of Guangzhou Military Command of PLA between May and December in 2016. All the samples were examined with 3 methods, namely enzyme-linked fluorescent spectroscopy for detecting Clostridium difficile toxin A/B (CDAB), detection of glutamate dehydrogenase (GDH), and q-PCR for amplification of Clostridium difficile-specific gene tpi and toxin gene (tcdA/tcdB), with the results of fecal culture as the reference for evaluating the diagnostic efficacy of the 3 methods. Results Of the total of 70 fecal samples, 13 (18.57%) were found to be positive for Clostridium difficile, including toxin-producing strains in 6 (8.57%) samples. The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic coincidence rate of q-PCR for tpi were 92.31%, 91.23%, 70.59%, 98.11% and 91.43%, respectively, which were significantly higher than those of GDH test (84.62%, 84.21%, 55.00%, 96.00%, and 84.29%, respectively; χ2=24.881, P<0.001). The sensitivity of q-PCR for tcdA/cdB was significantly higher than that of enzyme-linked fluorescent spectroscopy for CDAB in detecting CDI (66.67% vs 33.33%; χ2=35.918, P<0.001). Conclusion Both CDAB detection and q-PCR have a high specificity in detecting CDI, but GDH detection has a good sensitivity, and all these 3 methods have a high negative predictive value. Compared with other detection methods, amplification of tpi and tcdA/tcdB using q-PCR allows more rapid, sensitive and specific detection of CDI.