Abstract:Abstract:?Objective?To detect 13 kinds of pathogens in the specimens of patients with lower respiratory tract infections by the loop-mediated thermostatic amplification(LAMP)technique, and then provide the evidence for the rapid diagnosis of clinical infectious diseases.Methods?A total of 103 sputum samples and 45 alveolar lavage fluid specimens were collected from the patients with suspected lower respiratory infections.Bacteria and fungi were isolated by routine culture and identified by the matrix assisted laser desorption time-of-flight mass spectrometry(MALDI-TOF MS).Meanwhile, 13 kinds of common pathogens, including?Streptococcus?pneumoniae,?Staphylococcus?aureus, methicillin-resistant?Staphylococcus?aureus,?Escherichia?coli,?Klebsiella?pneumoniae,?Pseudomonas?aeruginosa,?Acinetobacter?baumannii,?Stenotrophomonas?maltophilia,?Haemophilus?influenzae,?Legionella?pneumoniae,?Chlamydia?pneumoniae,?Mycoplasma?pneumoniae?and?Mycobacterium?tuberculosis?complex group, were detected by the LAMP.Mycoplasma?pneumoniae?in 45 alveolar lavage fluid samples was detected by real-time fluorescent quantitative PCR(RT-qPCR).The samples with positive?Mycobacterium?tuberculosis?detected by the LAMP were further verified by the next generation sequencing(NGS).Results?The detection rate of pathogens by the MALDI-TOF MS was 42.6%(63/148), and 81 strains of pathogens were isolated.The detection rate of pathogens by the LAMP was 68.2%(101/148), and 175 kinds of pathogens were detected.There was no significant difference in the detection rate of?Staphylococcus?aureus,?Escherichia?coli,?Klebsiella?pneumoniae,?Pseudomonas?aeruginosa?and?Acinetobacter?baumannii?between the MALDI-TOF MS and LAMP(P>0.05), while the detection rates of?Streptococcus?pneumoniae, methicillin-resistant?Staphylococcus?aureus,?Haemophilus?influenzae?and?Stenotrophomonas?maltophilia?detected by the LAMP were significantly higher than those by the MALDI-TOF MS(P<0.05).Twenty-six cases of?Mycoplasma?pneumoniae?were detected from 45 alveolar lavage fluid specimens by the LAMP, while 23 were detected by RT-qPCR.In 148 samples, 2 cases of?Mycobacterium?tuberculosis?complex group were detected by the LAMP, and confirmed as positive by the NGS.Conclusion?Compared with traditional bacterial culture and identification, LAMP technique has advantages of rapidity, accuracy and simple, which can provide reliable evidence for clinical diagnosis and treatment.