Clinical Application Of Rapid Respiratory Pathogen Nucleic Acid Detection Technology In Severe Pneumonia

Objective:To evaluate whether the isothermal amplification on microarray chip can improve the diagnosis and treatment of severe pneumonia by comparing it with the pathogenic culture method and to explore the value of isothermal amplification on microarray chip in the diagnosis of severe pneumonia pathogens.Methods:Sputum or bronchoalveolar lavage fluid was collected from 68 patients with severe pneumonia collected from January 2021 to December 2022 in our hospital,and all patients were subjected to the pathogenic culture method.34 of them were further tested for pathogens by isothermal amplification on microarray chip.Age,gender,APACHE Ⅱ score,CURB-65 score,clinical complications,pathogen culture and the results of isothermal amplification on microarray chip were recorded for all patients.Clinical value was assessed by comparing the length of hospital stay,duration of mechanical ventilation,mortality after adjustment of antibiotics according to the results of the two methods and 28-Day in-hospital all-cause mortality in the isothermal amplification group and the pathogen culture alone group.Further,the value of isothermal amplification on microarray chip in pathogen diagnosis is assessed by the accuracy,reliability and consistency,using pathogen culture as the gold standard.Results:1.There was no statistically significant difference in the duration of mechanical ventilation and hospitalization-expenses in the isothermal amplification group compared to the pathogen isolation culture group,the length of hospital stay was longer in the isothermal amplification group than in the pathogen culture group,and there was no statistically significant difference in 28-day in-hospital all-cause mortality.2.There was no statistically significant difference in mortality after adjusting antibiotics according to the results of the thermostatic amplification test and pathogen culture.3.The distribution of pathogens in patients with severe pneumonia was dominated by Pseudomonas aeruginosa,Staphylococcus aureus,methicillin-resistant Staphylococcus aureus,Acinetobacter baumannii,Klebsiella pneumoniae,Stenotrophomonas maltophilia and Streptococcus pneumoniae,according to the results of the thermostatic amplification microarray.4.No statistical difference was found in the comparison of positive pathogen detection rate between isothermal amplification on microarray chip and pathogen culture method;38.24%of mixed pathogenic infections were detected in the isothermal amplification group;58.82%of mixed infections were detected in the conventional culture group,and there was no statistical difference in the identification ability of mixed infections between the two methods.5.The sensitivity of the thermostatic amplification chip for Pseudomonas aeruginosa,Acinetobacter baumannii and Klebsiella pneumoniae was more than 40%,among which the sensitivity of Streptococcus pneumoniae was 100%;except for methicillin-resistant Staphylococcus aureus and Staphylococcus aureus which were less specific,the specificity of other pathogens was more than 82%;Two pathogens,Streptococcus pneumoniae and Pseudomonas aeruginosa,are in good agreement in the consistency check,with the compliance rate of the pathogen detection by both methods greater than 61.76%.Conclusions:1.Compared to conventional pathogen culture methods,the isothermal amplification on microarray chip for pathogen detection in patients with severe pneumonia do not increase hospitalization-expenses,duration of mechanical ventilation,or hospital mortality,although hospital stays were slightly longer in the thermostatically amplified group.2.Compared to conventional pathogen culture methods,the isothermal amplification on microarray chip has high positivity,sensitivity and specificity for the detection of pathogens in patients with severe pneumonia,with the detection of Staphylococcus aureus being even better,and can be used as an auxiliary method for the diagnosis of pathogenic infections.3.The effective guidance rate of isothermal amplification method for adjusting antibiotics was not significantly different from that of conventional pathogenic testing.The low time-consuming and efficient characteristics of the isothermal amplification on microarray chips can help identify pathogens early and accurately and promote the rational management of clinical use of antibacterial drugs.