Chlamydia Trachomatis Detection And Genotyping From Infants And Young Children With Respiratory Infection

ObjectiveTo investigate the prevalence and genotype of Chlamydia trachomatis(CT) in children under 3 years old with respiratory infection.Methods322 nasopharyngeal secretion samples from 322 outpatient or hospitalized children under 3 years old with respiratory infection in the Children’s Hospital of Zhejiang University School of Medicine were collected from December 2013 to May 2014. Fluorescence quantitative polymerase chain reaction (F-Q PCR) was used to detect the deoxyribonucleic acid (DNA) of CT.26 strains were selected randomly. The gene code major out member protein1(omptl) was sequenced by dideoxy chain termination method and analyzed by Blast to determine the genotype of CT.ResultThe total detection rate of CT was 24.2% among the three age groups. The detection rate was 35.1% in the group under twenty-eight days old and 39.4% in the group between twenty-eight days old to 3 months old, no significant difference was found between the two young groups (P>0.05), but they were both significantly (P < 0.01) higher than the detection rate (8.7%) in group with 3 months up to 3 years old children.65 CT positive cases were detected in infants under 3 months old occupied 83.3% of total positive cases.The genotype of 26 CT were determined based on the sequence of ompl. There were 9 strains of type F,8 strains of type J,4 strains of type E,3 strains of type G, and 1 strain of type D and H respectively.ConclusionCT infection was mainly found in infants under 3 months old of the young children with respiratory infection. The detected genotype all belong to the type of urogenital infection. The dominant genotypes were type F、J and E. It showed that the CT which cause respiratory infection were from mother-to-child transmission. Cutting off this transmission route is one of the most effective measures to reduce the incidence of respiratory infection in infants under 3 months old.