Molecular epidemiology of Clostridium difficile

1.艰难梭菌在社区环境和家庭成员中携带和传播的分子流行病学研究（1）在由9个群体组成的1，413个个体中，总共有108个（7.6%）个体是C.艰难梭菌，但研究组之间的携带率范围为4.2%至15.3%。(2)通过PCR核糖分型和脉冲场凝胶电泳（PFGE）进行分型，证明了三组中的每一组中由单一类型定殖的载体的集群。(3)两个或两个以上的家庭成员是C。在22个家庭中有5个艰难梭菌阳性。C.这些发现表明，艰难梭菌的交叉传播可能是由一个家庭的成员中分离出一个相同类型的艰难梭菌。艰难梭菌在社区环境中发生，且C.在家里，家庭成员之间不经常发生艰难。对C.（1）在三所医院中，单一PCR核糖体型菌株（smz型）占优势，分别占34株中的22株（65%），28株中的18株（64%）和25株中的11株（44%）。所有代表PCR核糖体型smz的51个分离物由于DNA降解而无法通过PFGE分型。(2)所有51个SMZ型分离物都属于一个新的血清群（命名为血清群JP），与新制备的抗血清反应。(3)在健康成人分离株中未发现PCR核糖体分型的smz株。这些发现表明，PCR核糖体型smz、PFGE非型abe和血清群JP的菌株可能在日本流行。

1. Moleculay epidemiology of Clostridium difficile on carriage and transmission in community settings and family members(1) Out of 1,413 individuals, who were composed of nine groups, overall, 108 (7.6%) individuals were positive for C. difficile by faecal culture but carriage rates among the study groups ranged from 4.2% to 15.3%.(2) Typing by PCR ribotyping and pulsed-field gel electrophoresis (PFGE) demonstrated clusters, of carriers colonised by a single type in each of three groups.(3) Two or more family members were C. difficile-positive in five of 22 families examined. C. difficile with an identical type was isolated from persons within only one family.These findings indicate that cross-transmission of C. difficile cam occur in community settings, and that cross-transmission of C. difficile does not occur frequently among family members at home.2. Molecular analysis of C. difficile from nosocomial outbreaks in Japan(1) At three hospitals examined, a single PCR ribotype strain (type smz) was predominant and accounted for 22 (65%) of 34, 18 (64%) of 28, and 11 (44%) of 25 isolates, respectively. All of the 51 isolates that represented PCR ribotype smz were nontypeable by PFGE because of DNA degradation.(2) All 51 type smz isolates belonged to a new serogroup (designated serogroup JP), reacting with the newly prepared antiserum.(3) The PCR ribotype smz strain was not found among the isolates from healthy adults. These findings indicate that the strain with PCR ribotype smz, PFGE-nontypeabe and serogroup JP is likely to be epidemic in Japan.