Li Yuefeng, Xiong Likuan, Huang Yan, Xia Yong, Zhou Hua, Xu Fen, O'Sullivan Matthew V N
Department of Neonatology, Baoan Maternal and Child Health Hospital, Shenzhen 518133, China.
Central Laboratory, Baoan Maternal and Child Health Hospital, Shenzhen 518133, China.
Infect Genet Evol. 2015 Jan;29:48-52. doi: 10.1016/j.meegid.2014.11.004. Epub 2014 Nov 7.
Chlamydia trachomatis is a common sexually-transmitted bacterial pathogen. As no routine screening is performed during pregnancy, neonates and infants are at high risk for C. trachomatis infection. The objective of this study was to investigate the morbidity, clinical characteristics and genotype distribution of C. trachomatis pneumonia in infants less than six months of age.
Clinical manifestations and laboratory results were recorded. Respiratory sputum specimens were tested using RT-PCR targeting C. trachomatis cryptic plasmid. Simultaneously, respiratory virus antigens were detected by direct immunofluorescence and bacterial pathogens were examined by culture in all sputum samples. Positive C. trachomatis samples were further genotyped using a multiplex PCR reverse line blot assay. The relationship between genotype and pneumonia severity was explored.
Of 1408 infants, 101 (7.2%) were infected with C. trachomatis. Sixteen of 101 (15.8%) were assessed as severe pneumonia. These severe cases had a higher proportion of viral co-infection (37.5%) compared to mild pneumonia cases (9.4%, P<0.05).Infants with tachypnea (OR 9.2) and wheezing (OR 3.5) were more likely to be classified as severe pneumonia (P<0.05). Amongst 66 C. trachomatis specimens for which a genotyping result was available, seven genotypes were detected, and 39.4% of these specimens contained two or three genotypes. Overall, genotype E (48.5%) was the most frequent, followed by genotype F (42.4%), J (31.8%), D (12.1%), K (10.6%), G (4.5%) and H (3.0%). There were no significant correlations of particular genotypes with severity of disease, although there was a weak indication that more severe pneumonia might be associated with having certain mixed genotypes of C. trachomatis.
The prevalence of C. trachomatis in the population of young hospitalized infants with pneumonia in Shenzhen was very high. The relationship between genotype distribution and severity of pneumonia was not clear based on this study due to small sample size. Further in-depth investigation correlating genotype and disease severity based on a larger population is needed.
沙眼衣原体是一种常见的性传播细菌病原体。由于孕期未进行常规筛查，新生儿和婴儿感染沙眼衣原体的风险很高。本研究的目的是调查6个月以下婴儿沙眼衣原体肺炎的发病率、临床特征和基因型分布。
记录临床表现和实验室结果。使用针对沙眼衣原体隐蔽质粒的逆转录聚合酶链反应（RT-PCR）检测呼吸道痰液标本。同时，通过直接免疫荧光检测呼吸道病毒抗原，并对所有痰液样本进行细菌病原体培养检查。对沙眼衣原体阳性样本使用多重聚合酶链反应反向线印迹分析进一步进行基因分型。探讨基因型与肺炎严重程度之间的关系。
在1408名婴儿中，101名（7.2%）感染了沙眼衣原体。101名中的16名（15.8%）被评估为重症肺炎。与轻症肺炎病例（9.4%，P<0.05）相比，这些重症病例病毒合并感染的比例更高（37.5%）。呼吸急促（比值比9.2）和喘息（比值比3.5）的婴儿更有可能被归类为重症肺炎（P<0.05）。在66份有基因分型结果的沙眼衣原体标本中，检测到7种基因型，其中39.4%的标本含有两种或三种基因型。总体而言，E基因型（48.5%）最为常见，其次是F基因型（42.4%）、J基因型（31.8%）、D基因型（12.1%）、K基因型（10.6%）、G基因型（4.5%）和H基因型（3.0%）。虽然有微弱迹象表明更严重的肺炎可能与某些沙眼衣原体混合基因型有关，但特定基因型与疾病严重程度之间没有显著相关性。
深圳住院的患肺炎的低龄婴儿群体中沙眼衣原体的感染率很高。由于样本量小，本研究中基因型分布与肺炎严重程度之间的关系尚不清楚。需要基于更大的人群进一步深入研究基因型与疾病严重程度之间的相关性。
