Objective To evaluate three different Chlamydophila pneumoniae recombinant antigens for use in Chlamydophila pneumoniae serodiagnosis. Methods The recombinant plasmids pGEX6p-2/ Cpn0146,Cpn0147 and Cpn0308 were constructed and expressed as GST fusion proteins. The immunogenicity and the immunocompetence of these recombinant protein were analyzed by Western-blot and indirect ELISA. A total of 183 sera samples of patients with respiratory tract infection and 32 sera samples of patients with Chlamydia trachomatis infection were detected with indirect ELISA coated microwell plates with the purified recombinant proteins comparing with SeroCP-TM IgG ELISA kits. The positive recognition rate, sensitivity and specificity of each method were analyzed. Results GST-Cpn0146, Cpn0147 and Cpn0308 were obtained after expression and purification. The titers of the specific IgG antibodies against Cpn0146, Cpn0147 and Cpn0308 were higher than 1:6 400, 1:128 00 and 1:128 00, respectively. When the indirect ELISA was developed to detect the IgG antibody against Chlamydophila pneumoniae in 183 samples, the concordance rate between the indirect ELISA test and SeroCP-TM IgG ELISA kits were 92. 3% (Cpn0146) , 94.5% (Cpn0147) and 96.7% (Cpn0308), respectively. The recombinant Cpn0146, Cpn0147 and Cpn0308 were recognized by 71 (38.8% positive recognition rate), 75 (40.9%), and 82 (44.8%) samples, respectively. The recombinant antigen-based detection assays displayed > 97% of detection specificity and>87%of sensitivity.Condusion GST-Cpn0308 shows a better sensitivity and specificity,which suggests it could be used for developing serodiagnosis kits of Chlamydophila pneumoniae infection.

Objective To establish and evaluate a Metapneumovirus real-time quantitative reverse transcription polymerase chain reaction (RT-PCR),detect clinical specimens and explore the clinical prevalence characteristics of Metapneumovirus-infected children.Methods The primers and probes which targeted the conserved genes F were designed,RNA standards were prepared to establish a standard curve,the sensitivity,specificity and reproducibility had been tested.222 lower respiratory clinical specimens were collected from children in Lanzhou area with ARI.Metapneumovirus and co-infection viruses were detected simultaneously;further Metapneumovirus related epidemiology was studied.Results Metapneumovirus linear detection range was 10-10s copies/μl,the lowest detection limit was 10 copies/μl,the correlation coefficient was 1,the amplification efficiency was 91.62％,the CV of Ct value was less than 2％.Take conventional PCR product sequence results as reference,real-time quantitative RT-PCR sensitivity and specificity were 100％ and 96.17％.Metapneumovirus detection rate were 9.46％,13 cases for boys (5.86％),8 case for girls (3.60％).The detection rate of spring,summer,autumn and winter were 15.71％,0％,5.08％,11.11％.There were no significant differences between the Metapneumovirus viral load and mixed infection or the types of disease,clinical symptoms.Conclusions Metapneumovirus realtime quantitative RT-PCR has been confirmed as a sensitive and specific method.Metapneumovirus was an important agent of children respiratory tract infection in Lanzhou region.We should take the long-term systematic surveillance seriously.

Objective:To explore the pathogenic spectrum and epidemiological characteristics of respiratory viruses in children with acute lower respiratory tract infection in Changsha, and provide scientific basis for disease prevention and treatment.Methods:A total of 1 092 respiratory tract specimens of children were collected and 12 respiratory viruses were detected by real-time quantitative transcription polymerase chain reaction.Results:Among the samples from 1 092 cases, those from 437 cases (40%) were positive for respiratory syncytial virus (RSV), 337 cases (30.9%) were positive for parainfluenza virus-3 (PIV-3), 263 cases (24.1%) were positive for human bocavirus (HBOV) and 228 cases (20.8%) were positive for adenovirus (ADV). The detection rates of boys and girls were 82.26% and 83.42%. The infection rate of RSV was higher in the group ≤ 6 months of age, the infection rates of PIV-3 and HBOV ≤2 years old were higher, and the infection rate of ADV was higher in the group between 6 months to 5 years old. The detection rates of virus infection of spring, summer, autumn and winter were 90.48%, 83.50%, 62.26% and 82.80%, respectively, there were significant differences among them.Conclusions:The main viruses in children with acute lower respiratory tract infection in Changsha were RSV and PIV-3. Mixed infections were common. Children under 2 years of age were more likely to get acute lower respiratory infections. Viruses had seasonal trends and peaked in winter and spring.