Study On Molecular Diagnosis Of Community Acquired Pneumonia Pathogen

ObjectiveThe aim of the study was to investigate molecular technology application in the detection of pathogens isolated from patients with community acquired pneumonia and the clinical characteristics,provide reliable etiology evidence for clinical diagnosis and treatment.Methods416 adult patients were enrolled between March 2015 to December 2016 for the CAP from 3 hospitals,including Nanjing Drum Tower Hospital,JiangsuProvince Hospital TCM,Nanjing Jiangning Hospital.Oropharyngeal swabs,sputum was collected.The common seen bacteria and atypical and respiratory viruses pathogens of CAP was detected by Using the multiplex nucleic acid detection technology(xTAG RVP,SeeplexPB),and also etiological distribution,clinical symptoms,laboratory test results and imaging manifestation were evaluated.ResultsA total of 416 patients with etiologic evaluation were included in our study,consisted of 203 males and 213 females,and the male/female ratio of 0.95/1.The mean age was 52.44 years(range,18-93 years).Most of the patients with CAP had cough,sputum,and fever.Only moist crackles have statistical significance.Of 416 patients,196 patients had positive microbiologic study results including 133 patients with bacterial infection,19.23%of patients with viral infection,and 7.21%patients with atypical pathogen.Among bacterial infection,S.pneumonia was the commonest pathogen isolated from 130 patients;E/R virus was at rank of the No.1 detected viral infection.Multiple infection were detected in 13.46%of all patients(56/416).There were no significant differences among single infection with bacteria,atypical or viral infection in sex and no obvious correlation between age and positive detection rate for bacteria and virus.Viral pathogens positive rate showed a trend toward decrease following with the time consuming within a year,the difference was statistically significant,(χ2=5.152,P=0.023).there were significant differences of the positive rate of atypical pathogens among different age groups,specifically,the rate decreased as the age increased.(χ2=17.546,P<0.001).For laboratory parameters,there was no statistical difference among the three groups for white blood cell counts,neutrophil percentage,lymphocyte percentage and C-reactive protein.Most of them have normal white blood cell counts,high neutrophil percentage and low lymphocyte percentage.For X-ray or CT chest images,bacterial and viral pathogens are mainly related with bilateral changes of the lung,lesions on image were more commonly seen in the right-side lung than the left one,for patients with atypical pathogens,most of them were shown as infiltrates on the left single lung rather than multiple infiltrates on the both sides..Conclusion1.Molecular biology technology is of high sensitivity for detection community acquired pneumonia pathogens with a high positive rate.2.The most common pathogens in patients with CAP is streptococcus pneumonia,followed by enterovirus/rhinovirus.3.The CAP patients have lack of characteristic clinical symptoms,most of them have cough,sputum,and fever.4.The positive of rate of atypical pathogens were correlation with age,and gradually decline with increased age,positive rate of viral pathogens had a trend toward decrease following with time consuming within a year,bacterial pathogens did not see the above changes.5.The laboratory parameters including white blood cell counts,neutrophil percentage,C-reactive protein were not significantly different among those CAP patients having different pathogenic infection.