慢性腹泻患者艰难梭菌、人芽囊原虫和隐孢子虫感染的研究

Infections of Clostridium difficile, Blastocystis hominis and Cryptosporidium spp. in patients with chronic diarrhea

收集江苏大学附属医院2018年收治的慢性腹泻患者粪样,涂片镜检并提取粪样DNA,采用多重PCR技术检测粪样中艰难梭菌16S rDNA基因、毒素A(tcdA)基因、毒素B(tcdB)基因和二元毒素(cdtA和cdtB)基因;常规PCR检测人芽囊原虫SSU rRNA基因;巢式PCR检测隐孢子虫SSU rRNA基因。96份慢性腹泻患者粪样中,检出艰难梭菌16S rDNA基因64份,阳性率为66.7%;艰难梭菌阳性粪样中,tcdA基因24例,tcdB基因18例,未检出单独携带tcdB基因粪样,产毒株携带率为37.5%,所有粪样中均未检出cdtA基因和cdtB基因;镜检结果显示,人芽囊原虫粪样16份,检出率为16.7%;PCR结果显示,21份粪样扩增出人芽囊原虫SSU rRNA基因,检出率为21.9%,镜检阳性粪样PCR检测也为阳性;未检测到艰难梭菌和人芽囊原虫混合感染;未检出隐孢子虫SSU rRNA基因。江苏大学附属医院慢性腹泻患者中主要检出的病原体为艰难梭菌和人芽囊原虫。

Ninety-six stool samples were collected from patients with chronic diarrhea at affiliated hospital of Jiangsu University(inpatients and outpatients)in 2018.Each stool sample was smeared for microscopic examination.At the same time fecal DNA was extracted.The genes for 16S rDNA,toxin A(tcdA),toxin B(tcdB),binary toxin(cdtA and cdtB)of Clostridium difficile were detected by multiplex PCR.The SSU rRNA gene of Blastocystis hominis was detected by conventional PCR and the SSU rRNA gene of Cryptosporidium spp.was detected by nest-PCR.C.difficile 16S rDNA was detected in 64 out of 96 patients with chronic diarrhea with a positive rate of 66.7%.C.difficile TcdA gene was detected in 24 cases and tcdB gene in 18 cases of all C.difficile positive samples.There was no sample with only tcdB.No cdtA and cdtB genes were detected in any C.difficile positive sample.The rate of toxigenic strain was 37.5%.Microscopic examination detected 16 B.hominis infected samples with detection rate of 16.7%.PCR results showed that 21 samples B.hominis SSU rRNA gene was amplified in 96 stool samples with a detection rate of 21.9%.All microscopic positive samples were positive in PCR detection.No mixed infection of C.difficile and B.hominis was detected.The Cryptosporidium spp.SSU rRNA gene was not detected in all stool samples.The results showed that C.difficile and B.hominis were the main organisms detected in patients with chronic diarrhea in Nanjing area.