[Colonization rate of Clostridium Difficile in healthy children]

Objective: 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.