摘要目的 调查健康儿童中产毒的艰难梭菌定植情况,了解各年龄段产毒艰难梭菌的定植率及其毒素类型.方法 病例观察性研究,连续性收集2014年9月至2015年1月北京儿童医院保健科健康儿童的粪便标本,按年龄分4组,分别是＜1岁53例,1～＜3岁、3～＜6岁和6～ ＜14岁组各50例,共203例,应用PCR检测艰难梭菌的毒素基因,包括tcdA、tcdB及二元毒素基因,并检测其毒素调节基因,包括tcdC、tcdD、tcdE.对阳性结果进行基因测序分析.计量资料组间比较采用t检验、秩和检验,计数资料采用x2检验.结果 入组的203例标本中共检测出产毒艰难梭菌阳性标本15例(7.4％),其中tcdA阳性而tcdB阴性(A+B-)基因型8例,tcdA、tcdB均阳性(A+B+)基因型4例,tcdA阴性而tcdB阳性(A-B+)基因型3例(20.0％),未检测到二元毒素阳性标本.tcdC、tcdD、tcdE基因阳性的标本分别为8例(53.3％)、6例(40.0％)、11例(73.3％).tcdA、tcdB、tcdC、tcdD、tcdE基因阳性标本经测序未发现基因突变.在15例阳性标本中,＜1岁组检出4例(4/53,7.5％);1～＜3岁组检出4例(4/50,8.0％);3～＜6岁组检出1例(1/50,2.0％);6～＜14岁组检出6例(6/50,12.0％),各年龄组产毒艰难梭菌定植率差异无统计学意义(P＞0.05).结论 本组产毒的艰难梭菌在健康儿童中的定植率为7.4％,且各年龄组均可检测到产毒的艰难梭菌.

abstractsObjective To learn the colonization of Clostridium difficile in local healthy children and to investigate the colonization rate and toxin types of Clostridium difficile at different ages.Method From September 2014 to January 2015 in a case observational study,healthy children's fecal specimens from the health care department of Beijing Children's Hospital were collected.The children were divided into four groups according to age:＜ 1 year old(n =53),1-＜3 years old(n =50),3-＜6 years old(n =50) and 6-＜ 14 years old(n =50) respectively.Polymerase chain reaction (PCR) was used to detect Clostridium difficile toxin genes including tcdA,tcdB,binary toxin CDT (cdtA and cdtB),and toxin regulatory genes including tcdC,tcdD and tcdE.And then the positive samples were sequenced.Measurement data were compared by using t test and rank sum test,while,enumeration data were compared using chi-square test.Result Fifteen (7.4％) specimens were positive for Clostridium difficile toxin genes in 203 stool specimens.Of the 15 positive specimens,eight (53.3 ％) were tcdA + tcdB-(A + B-),four were A + B +,3 (20.0％) were A-B +,the binary toxin-positive specimens were not detected.TcdC,tcdD,tcdE positive specimens were 8,6 and 11,respectively.Gene mutations were not found in positive samples by DNA sequencing.In the 15 positive samples,four (7.5％) specimens were in ＜ 1 year old group;four (8.0％) specimens were in 1-＜ 3 years old group;one(2.0％) specimen was in 3-＜ 6 years old group;and 6(12.0％) specimens were in 6-＜ 14 years old group.The colonization rate had no significance in different age groups.Conclusion The colonization rate of Clostridium difficile in healthy children was 7.4％.And toxigenic Clostridium difficile can be detected in all age groups.