Abstract:

Objective: To explore the distribution characteristics and drug resistance differences of pathogenic bacteria in patients with pulmonary tuberculosis and non-pulmonary tuberculosis combined with lower respiratory tract infections, and to provide a basis for clinical precise medication. Methods: A cross-sectional survey design was adopted. A total of 11854 patients with pulmonary infections who were admitted to the Public Health Clinical Center of Shandong Province from January 2021 to December 2024 were selected as the research subjects. Through medical record inquiries, those with incomplete medical records were excluded, and the patients were divided into the pulmonary tuberculosis complicated with lower respiratory tract infection (PTB-LRTI) group (2047 cases), the non-tuberculous mycobacterial lung disease complicated with lower respiratory tract infection (PNTM-LRTI) group (385 cases), and the bacterial pneumonia (BP) group (1869 cases) based on clinical diagnosis. Respiratory tract specimens such as sputum, bronchoalveolar lavage fluid, and brushes of the research subjects were collected for bacterial culture. The positive bacterial strains were subjected to drug sensitivity tests, and duplicate isolates from the same patient were excluded. The pathogen spectra and drug resistance characteristics of the respiratory tract specimens of the three groups of research subjects were compared and analyzed. Results: Gram-negative bacteria were the main pathogens in the three groups. Klebsiella pneumoniae (32.30%,773/2397), Pseudomonas aeruginosa (14.95%,358/2397), Enterobacter cloacae (9.02%,216/2397), Escherichia coli (8.40%,201/2397), and Acinetobacter baumannii (4.22%,101/2397) were the top five pathogens detected in the PTB-LRTI group, which were the same as those in the PNTM-LRTI group. Pseudomonas aeruginosa (27.38%,555/2027), Klebsiella pneumonia (21.41%,434/2027), Stenotrophomonas maltophilia (7.05%, 143/2027), Acinetobacter baumannii (6.66%,135/2027) and Staphylococcus aureus (5.28%,107/2027) were the top five pathogens detected in the BP group. The resistance rate of Klebsiella pneumoniae to piperacillin/tazobactam (4.40%, 24/773) and imipenem (0.78%, 6/773) was low in the PTB-LRTI group; the resistance rates of Pseudomonas aeruginosa to piperacillin/tazobactam (5.31%, 19/358), ceftazidime (5.59%, 20/358), and imipenem (13.41%, 48/358) were significantly different from those of the PTB-LRTI group and BP group (χ²=15.139, P=0.001; χ²=15.524, P<0.001; χ²=9.148, P=0.010); the resistance rate of Acinetobacter baumannii to the tested antibiotics is less than 30%; the resistance rate of Staphylococcus aureus to rifampicin (13.89%, 5/36) was significantly higher than that of the BP group (2.80%, 3/107), and the difference was statistically significant (χ²=8.308, P=0.016). There were differences in the distribution of carbapenem-resistant enterobacteriaceae (CRE) bacteria among the three groups. In the PTB-LRTI group, the detection rate of CRE was the highest for Enterobacter cloacae (35.42%, 17/48), followed by Klebsiella pneumoniae (14.58%, 7/48) and Escherichia coli (14.58%, 7/48). Conclusion: There are significant differences in the distribution of pathogenic bacteria and drug resistance characteristics between PTB-LRTI, PNTM-LRTI and BP. Clinically, it was necessary to use antibacterial drugs rationally based on the results of drug sensitivity tests, and at the same time, strengthen infection control measures to reduce the risk of infection with drug-resistant bacteria.

Key words: Tuberculosis, pulmonary, Pneumonia, bacterial, Respiratory tract infections, Drug resistance, bacterial