酶联荧光免疫分析技术检测粪便中艰难梭菌毒素A/B

目的应用酶联荧光免疫分析(ELFIA)技术及PCR联合检测粪便标本中艰难梭菌毒素A/B(CDAB),分析不同临床表现的住院患者粪便标本中CDAB的检出情况。方法收集北京大学第一医院2010年8月～11月242位住院患者粪便标本,用ELFIA法检测CDAB,对检测结果为可疑的标本用PCR复测。将患者分为非抗生素相关腹泻组和抗生素相关腹泻组,对两组的CDAB阳性率进行χ2检验,并分析检测结果与临床表现的相关性。结果 242位患者中,22例ELFIA法CDAB检测为阳性,12例检测结果为可疑。12例可疑标本有10例进行了PCR复测,8例(80.0%)CDAB基因阳性。两法联合检测共计30例为CDAB阳性,阳性率为12.4%。抗生素相关腹泻组CDAB阳性率(24.0%)显著高于非抗生素相关腹泻组(6.9%)(χ2=14.21,P<0.01)。CDAB阳性组的年龄(68.2±23.6)岁高于CDAB阴性组(58.7±23.9)岁(P<0.05)。结论 ELFIA法检测CDAB,有商品试剂盒,方法简便可靠。可疑阳性标本用PCR法检测tcdA/tcdB基因,可进一步提高阳性率。艰难梭菌毒素在抗生素相关腹泻患者检出率较高,与临床表现具有较好的相关性。

Detection of Clostridium difficile toxins A and B in inpatient stool samples by enzyme-linked fluorescent immunoassay

Objective To detect Clostridium difficile toxins A/B(CDAB) in stool samples of inpatients by enzyme-linked fluorescent immunoassay(ELFIA) and PCR and analyze the yields of CDAB in stool samples from inpatients with different clinical features.Methods The stool samples from 242 inpatients of Peking University First Hospital were collected from August to November 2010.CDAB was detected by ELFIA and the equivocal samples were retested by PCR.The inpatients were divided into 2 groups: non-antibiotic associated diarrhea(NAAD) and antibiotic associated diarrhea(AAD).The CDAB positive rates of 2 groups were compared by chi-square test.The correlation of laboratory results and clinical features were analyzed.Results Among the 242 inpatient samples studied,22 were toxins-positive and 12 were equivocal.Ten of 12 equivocal samples were retested by PCR and 8(80.0%) were positive for the toxin genes.Totally 30(12.4%) samples were defined as the toxin-positive by combined two methods.The toxin-positive rate(24.0%) in AAD group was significantly higher than that(6.9%) of NAAD group(χ2= 14.21,P<0.01).The age of patients of CDAB-positive group was older (68.2±23.6) years old] than those(58.7±23.4) of CDAB-negative group(P<0.05).Conclusions The commercial kit using ELFIA was convenient and reliable for detection of CDAB.Retesting the equivocal samples by PCR for tcdA/tcdB genes could raise the positive rate.The positive rate of CDI was higher in AAD patients which highly correlated with the clinical features of inpatients.