To investigate the clinical values of the loop-mediated amplification (LAMP) chip in the gene diagnosis of common pathogens in the lower respiratory infections.

A total of 266 deep sputum samples from the lower respiratory tract were collected from the patients with suspected lower respiratory infection by fiber bronchoscopy. The pathogens were tested by LAMP or traditional isolation and cultivation. Finally, the relevance ratio of the pathogens and the values of the LAMP in the lower respiratory infections were analyzed.

Positive results of the pathogens detected by LAMP were found in 155 samples, with the positive ratio of 58.27%. Among them, single pathogen infection was found in 90 cases (33.83%) and mixed infections were found in 65 cases (24.44%). Beyond that, 11 kinds of respiratory pathogens were checked out and the top three were Acinetobacter baumannii (21.05%), Methicillin-resistant Staphylococcus (MASA, 20.30%) and Pseudomonas aeruginosa (12.03%). At the same time, traditional isolation and cultivation was adopted in 257 samples, among which, 92 samples were cultivated to be positive, with the positive ratio of 35.8%. In details, Acinetobacter baumannii was found in 44 samples (47.83%), Pseudomonas aeruginosa in 23 samples (25%) and Klebsiella pneumoniae in 8 samples. However, the Pneumonia streptococcus and Staphylococcus aureus were cultivated to be negative.

The LAMP has the advantages of rapidity, sensitivity, high efficiency and specificity, and wide coverage of the pathogens, which could be taken as a quick and reliable laboratory diagnosis basis for clinical application.