The Establishment And Preliminary Application Of Molecular Diagnosis To Community Acquired Pneumonia

Objectives:To initially establish a molecular diagnostic method for community-acquired pneumonia(CAP),and to investigate the distribution of pneumonia cases in Dali,Yunnan,in order to approximately clarify the pathogenic pathogen spectrum and provide reference for clinical diagnosis and treatment.Methods:1.The compare and combination of real-time quantitative PCR(qPCR)primer:Combine pairs with the existing single primer for common bacteria and atypical pathogens that caused CAP are,there are 6 kinds of bacteria(Streptococcus pneumoniae,Staphylococcus aureus,Klebsiella pneumoniae,Pseudomonas aeruginosa,Moraxella catarrhalis,flu Haemophilus)and 3 atypical pathogens(Legionella pneumophila,Mycoplasma pneumoniae,Chlamydia pneumoniae),than compare the combination to the single primer.Campare the existing primers for 6(14 subtypes)viruses(Respiratory syncytial virus A,B,Parainfluenza 1-4,Human metapneumovirus,Boca virus,influenza A and B viruses,corona virus OC43,NL63,229E,HKU1).2.Respiratory specimens collection:The hospitalized patients diagnosed as"community-acquired pneumonia" from February 2017 to March 1818 in a hospital in Dali was selected as a survey object,and collected respiratory specimens including sputum,alveolar lavage fluid and pleural effusion.3.Pretreatment of respiratory specimens:The sputum specimens were trypsinized,and the alveolar lavage fluid and pleural effusion were directly used for the lower layer sedimentation.4.Respiratory pathogen detection:QPCR detection of 6 bacteria,3 atypical pathogens and 6(14 subtypes)viruses in 428 respiratory specimens.5.Cases information collection:Find the ID number by specimen number;obtain basic information of the case,clinical symptoms,physical examination,the results of laboratory testing,imaging results,and remove the cases diagnosed as"pulmonary tuberculosis" and "lung tumor"6.Analysis:The method statisticing and analysising of experimental data is chi-square testing by SPSS 17.0,test level a=0.05.Results:1.Primer determination:Compare the CT value of single primer and the combined primer and virus single primer and Virus two-color primer to the same positive control.The difference between the bacterial combination primer and the single primer CT value is small,and the virus(except corona virus)two-color primer more sensitive than the single primer,the single primer for corona virus is more sensitive.Determine the combination of primer for the detection of bacteria and atypical pathogens in respiratory specimens,virus detection of respiratory syncytial virus,parainfluenza virus,human metapneumovirus,boca virus,influenza virus using the two-color primer,while corona virus still uses the single primer detecting the respiratory specimens.2.Infection of CAP cases:428 copies came from 170 patients.Among the 170 cases,qPCR results were combined with hospital isolation and culture results.The bacterial infection was 13.53%,the simple virus infection rate was 22.94%,and the simple atypical pathogen(Mycoplasma pneumoniae)infection rate was 3.53%.Fungus(C.albicans)has a simple infection rate of 4.71%and the multiple infections of 28.82%.3.Case infection:The main simple bacterial caused CAP is Haemophilus influenzae,the virus is main influenza A and B viruses,Legionella pneumophila and Chlamydia pneumoniae are not detected,and some cases are caused by fungal pneumonia.Conclusions:Molecular diagnostic methods for CAP against 23(type)pathogens were initially established and combined.Preliminary clarification of the infection of CAP in Dali’s hospital,the main bacteria in CAP are Haemophilus influenzae,the most virus in CAP is influenza virus,and there is a certain proportion of mycoplasmal pneumonia and fungal pneumonia,the multiple infections should also pay attention.