Etiological Characteristics Of 100 Patients With Severe Pneumonia In An Affiliated Hospital Of Jilin University

Background:Severe pneumonia is a common clinical emergency and anti-infection is the core of its treatment,which requires early,comprehensive and rapid identification of the infecting agent.Current clinical methods for obtaining pathogenic results include traditional pathogenic testing methods and metagenomics Next Generation Sequencing(m NGS)technology.We summarize the pathogens of severe pneumonia infection detected by two pathogenic methods applied at the Second Hospital of Jilin University,which can help guide the selection of early empirical anti-infection regimens for patients with severe pneumonia.Objective:To clarify the characteristics of pathogen distribution in patients with severe pneumonia and the characteristics of infectious pathogens in patients with severe pneumonia combined with different underlying diseases,and to explore the application value of m NGS in the detection of pathogens in severe pneumonia.Methods:The clinical diagnosis of severe pneumonia admitted to the Second Hospital of Jilin University from September 2019 to October 2022 and sent for sputum or bronchoalveolar lavage fluid(BALF)or blood m NGS testing and traditional pathogenic testing(including general bacterial/fungal culture,antacid bacillus smear,G test/GM test,and Respiratory virus Ig M antibodies and mycoplasma,chlamydia and Legionella Ig M antibodies)of 100 patients were statistically analyzed for clinical data and pathogenic results.Patients with severe pneumonia were divided into different subgroups according to their underlying diseases,and the characteristics of pathogens in different subgroups were clarified.Results:1.In 100 patients with severe pneumonia,24 species/131 strains of bacteria(including 5strains of Mycobacterium tuberculosis),commonly Pseudomonas aeruginosa,Acinetobacter baumannii,Streptococcus maltophilia,Enterococcus,Streptococcus pneumoniae,and Staphylococcus aureus;5 species/50 strains of viruses,commonly cytomegalovirus and herpes simplex virus;and 7 species/36 strains of fungi,commonly Pneumocystis,Aspergillus,and Candida albicans,were detected by the m NGS technique in combination with traditional pathogenetic testing methods.2.The mNGS technique detected 33 species/203 strains of pathogens,the common bacteria are Pseudomonas aeruginosa,Acinetobacter baumannii,Oligotrophomonas maltophilia,Klebsiella pneumoniae,Enterococcus faecalis,Streptococcus pneumoniae,Staphylococcus aureus;the common fungi are Pneumocystis,Aspergillus,Candida albicans;the common viruses are cytomegalovirus and herpes simplex virus.3.Traditional pathogenic methods detected 19 species/75 strains of pathogens,the common bacteria were Acinetobacter baumannii,maltophilic oligotrophic singletons,Pseudomonas aeruginosa,Klebsiella pneumoniae,and Staphylococcus aureus;the common fungi were Candida albicans.4.Pathogenic detection in each underlying disease subgroup:(1)The common pathogens of autoimmune diseases combined with severe pneumonia were cytomegalovirus,herpes simplex virus,and Pneumocystis,and all of the above pathogens were detected by m NGS.(2)The common pathogens of severe pneumonia combined with radiotherapy for malignant tumors were cytomegalovirus,Pneumocystis,Aspergillus,and herpes simplex virus.Among the 8cytomegalovirus strains(all detected by m NGS),only 1 strain was detected by conventional pathogenic methods;both Pneumocystis and herpes simplex virus were detected by m NGS;among the 4 Aspergillus strains(all detected by m NGS),only 1 strain was detected by conventional pathogenic methods at the same time.(3)The common pathogens of severe pneumonia in combination with cerebrovascular disease were Oligomonas maltophilia,Pseudomonas aeruginosa,herpes simplex virus,Staphylococcus aureus,Klebsiella pneumoniae,and cytomegalovirus.m NGS and traditional pathogenic methods were consistent in detecting Oligomonas maltophilia,Pseudomonas aeruginosa,and Klebsiella pneumoniae(Kappa=0.46、0.47、0.60);among the four strains of S.aureus(all detected by m NGS),only 1 strain was detected by conventional pathogenic methods;herpes simplex virus and cytomegalovirus were detected by m NGS.(4)The common pathogens of chronic airway disease combined with severe pneumonia were Pseudomonas aeruginosa,Acinetobacter baumannii,Enterococcus,and Klebsiella pneumoniae,etc.The detection of Pseudomonas aeruginosa,Acinetobacter baumannii,and Klebsiella pneumoniae by m NGS and traditional pathogenic methods were consistent(Kappa=0.48、0.67、0.45);enterococci were all detected by m NGS.Conclusions:1.The pathogens with a high detection rate in patients with severe pneumonia are bacteria,including Pseudomonas aeruginosa,Acinetobacter baumannii,Maltophila oligomonas,and Klebsiella pneumoniae;The detection rate of viruses and fungi is also high.2.Autoimmune diseases combined with severe pneumonia common pathogens are cytomegalovirus,herpes simplex virus,pneumocystis;malignant tumor radiotherapy combined with severe pneumonia common pathogens are cytomegalovirus,pneumocystis,Aspergillus,herpes simplex virus;cerebrovascular disease combined with severe pneumonia common pathogens are maltophilia oligotrophic monocytic bacteria,Pseudomonas aeruginosa,herpes simplex virus;chronic airway disease combined with severe The common pathogens of pneumonia are: Pseudomonas aeruginosa,Acinetobacter baumannii,Enterococcus,Klebsiella pneumoniae.3.mNGS has an advantage in the detection of cytomegalovirus,herpes simplex virus,pneumocystis,Aspergillus,and Mycobacterium tuberculosis,and it is recommended that patients with severe pneumonia be sent for m NGS early testing to confirm the infectious agent.