To investigate the clinical distribution of pathogenic bacteria in children's lower respiratory tract by using loop-mediated isothermal amplification (LAMP), so as to provide reference for practical clinical work.

2517 patients with respiratory tract pathogenic bacteria infection (from Autumn, 2018 to July, 2019) initially diagnosed in Tianjin Children's Hospital-Pediatrics Research Institute were enrolled in the study. The bronchoalveolar lavage fluid samples or deep sputum samples were collected and 13 kinds of pathogenic bacteria in the lower respiratory tract were detected by LAMP microarray, and the detection results were analyzed.

The LAMP microarray was used to detect 2517 cases of lower respiratory tract infections in hospitalized children, and a total of 1771 cases were positive for pathogenic bacteria (sputum 1174 cases (46.64%) and alveolar lavage solution 597 cases (23.72%). The main pathogenic bacteria were Mycoplasma pneumoniae in 934 cases (37.11%), Streptococcus pneumoniae in 557 cases (22.13%), methicillin-resistant Staphylococcus in 397 cases (15.78%), Haemophilus influenzae in 295 cases (11.72%) and Staphylococcus aureus in 214 cases (8.50%). The positive rates of respiratory tract pathogenic bacteria in different seasons are different. Mycoplasma pneumoniae infection in children occurs throughout the year, mostly in autumn and winter, Streptococcus pneumoniae infection occurs mainly in winter, and methicillin-resistant Staphylococcus aureus in spring, and Haemophilus influenzae in spring and summer. There were 1179 cases of single pathogen infections (46.84%) and 1338 cases of mixed infections (53.16%).

For the detection of lower respiratory tract pathogenic infection in children, the LAMP microarray is a simple, rapid and accurate method. It can significantly shorten the standard turnover time (TAT), and has the advantages of higher sensitivity and wide pathogen coverage, which can better serve the rapid diagnosis of infectious diseases, early screening and rational use of antibiotics.