关键词: 呼吸重症科, 下呼吸道感染, 病原菌, 耐药性, 环介导等温扩增

Abstract:

Objective To investigate the pathogenic and epidemiological characteristics of patients with lower respiratory tract infection in respiratory intensive care unit，and to provide a reference for clinical diagnosis and epidemiological investigation. Methods A total of 2 382 sputum and alveolar lavage fluid specimens were collected from the patients with lower respiratory tract infection in respiratory intensive care units of 3 Grade A Class 3 hospitals in Xinxiang from 2019 to 2020. The pathogens were determined by loop-mediated isothermal amplification（LAMP） and bacterial culture methods. The consistency of 2 methods was evaluated. The pathogen distribution with different ages and between females and males was evaluated. The positive rate with different seasons was evaluated. The drug susceptibility was analyzed by disk diffusion method. Results Among the 2 382 specimens，the main pathogens were Acinetobacter baumannii（19.40%），methicillin-resistant Staphylococcus aureus（17.25%） and Klebsiella pneumoniae（13.98%）. Methicillin-resistant Staphylococcus aureus and Haemophilus influenza were prevalent in the population <20 years old. Acinetobacter baumannii was mainly infected the population ≥60 years old. The total positive rates of pathogens in patients with lower respiratory tract infection with different ages and sex had statistical significance（P<0.001）. Except for Klebsiella pneumoniae，Acinetobacter baumannii and Haemophilus influenza，the difference of the other pathogens in each season was statistically significant（P<0.05）. Acinetobacter baumannii was the pathogen with the highest infection rate in male and female patients，but the infection rates of Staphylococcus aureus，Pseudomonas aeruginosa and Stenotrophomonas maltophilia showed no statistical significance in male and female patients（P>0.05）. The drug resistance of different Gram-negative bacilli had difference. The consistency between LAMP and bacterial culture methods was poor （the Kappa value was 0.221，P<0.001）The Kappa value for Klebsiella pneumoniae was 0.408（P<0.001）. Conclusions The pathogens with the highest determination rate in lower respiratory tract infection among respiratory intensive care unit patients are Acinetobacter baumannii，followed by methicillin-resistant Staphylococcus aureus，Klebsiella pneumoniae and Pseudomonas aeruginosa，while the infection rates of different pathogens differ with different seasons and between males and females，and LAMP plays a role in screening lower respiratory tract pathogens.

Key words: Respiratory intensive care unit, Lower respiratory tract infection, Pathogen, Drug resistance, Loop-mediated isothermal amplification