不育男性精液中大肠埃希菌及其毒力基因对精子活力影响的研究

Effects of Escherichia coli and its virulence factors in semen on sperm motility of male infertility patients

目的探讨不育男性精液中大肠埃希菌感染对精子活力的影响,并分析大肠埃希菌毒力基因在不同精子活力组间的表达差异。方法回顾性收集2022年1月至2023年2月就诊于温州市中医院的不育男性精液445份和男性志愿者正常精液15份,进行细菌培养后从72例不育男性患者精液中分离出非重复大肠埃希菌72株,分别与正常精液孵育30 min后检测精子活力,其中引起精子活力明显降低的菌株归为制动阳性组,其余菌株归为制动阴性组。同时采用PCR法对大肠埃希菌相关毒力基因fimH、papGⅡ、papGⅢ、afa/dra、cnf-Ⅰ、kpsMTⅡ、hlyA、fyuA和菌体O抗原(O1、O_(2)、O4、O6)进行检测,分析以上毒力基因在制动阴性组和制动阳性组中检出率的差异。结果大肠埃希菌携带的主要毒力基因有fimH、fyuA、kpsMTⅡ、hlyA、cnf-Ⅰ,检出率分别为95.8%、83.3%、81.9%、45.8%及40.3%。72株大肠埃希菌中制动阳性组占42株,制动阴性组占30株。制动阳性组毒力基因hlyA检出率57.1%,远高于制动阴性组的30.0%,差异有统计学意义(P<0.05),其余毒力基因检出率比较差异均无统计学意义(均P>0.05)。结论不育男性精液中精子活力降低可能与大肠埃希菌α-溶血素编码基因hlyA相关。

Objective To investigate the effects of Escherichia coli(E.coli)and its virulence factors in semen on sperm motility of male infertility patients Methods Semen samples of 445 sterile male patients admitted to Wenzhou Hospital of Traditional Chinese Medicine from January 2022 to February 2023 were collected,and 72 non-repeating strains of E.Coli were isolated,and sperm motility was detected after incubation with normal semen for half an hour.The strains that caused significant decrease in sperm motility were classified as sperm immobilization-positive(SI-positive)group,and the other strains were classified as sperm immobilization negative(SI-negative)group.Escoli virulence genes fimH,papGⅡ,papGⅢ,afa/dra,cnf-Ⅰ,kpsMTⅡ,hlyA,fyuA and cell O antigen(O1,O_(2),O4,O6)were detected with PCR method,and the detection rates of these virulence genes were compared between the two groups.Results The positive rates of fimH,fyuA,kpsMTⅡ,hlyA and cnf-Ⅰgenes were 95.8%,83.3%,81.9%,45.8%and 40.3%,respectively.Forty-two of the 72 E.coli strains significantly reduced sperm motility.The detection rate of virulence gene hlyA in the SI-positive group was significantly higher than that in SI-negative group(57.1%vs.30.0%,P<0.05).There were no significant differences in the detection rates of other virulence genes between the two groups(all P<0.05).Conclusion The decrease of sperm motility in semen of infertile men may be related to theα-hemolysin encoding gene hlyA of E.coli.