Abstract: Objective The distribution of pathogenic bacteria, possible high-risk factors and prognosis of patients with tuberculosis complicated with pneumonia were analyzed to provide reference for clinical diagnosis and treatment strategies of this kind of patients. Method This study analyzed 352 tuberculosis patients treated at the General Hospital of the Eastern Theater Command of the People's Liberation Army from December 2015 to December 2023. Sputum samples were collected from all patients with tuberculosis complicated by pneumonia to examine pathogen distribution patterns. Multivariate Logistic regression was employed to identify factors contributing to tuberculosis-related pneumonia. Patients developing severe pneumonia underwent one-year follow-up with mortality data analysis to assess the proportion of risk factors among fatalities. Result Among 352 tuberculosis patients included in this study, 156 patients developed pneumonia, with an incidence rate of 44.32%. Through pathogen detection of these patients, a total of 305 bacterial strains were isolated. Among them, Gram-negative bacteria accounted for the most significant proportion, reaching 60.66%. Multivariate Logistic regression analysis showed that diabetes（OR=1.417,95%CI：1.141-1.708）, hypertension（OR=1.494,95%CI：1.114-1.874）, chronic bronchitis（OR=1.431,95%CI：1.106-1.741）, continuous use of broad-spectrum antibiotics for 3 weeks or longer（OR=1.531,95%CI：1.177-1.879）, continuous use of glucocorticoids for 2 weeks or longer（OR=1.628,95%CI：1.241-2.015）, disease duration 5 years or longer（OR=1.459,95%CI：1.118-1.752）, retreatment with pulmonary tuberculosis(OR=1.605,95%CI：1.205-2.005), malnutrition(OR=1.741,95%CI：1.201-2.234), failure to fully adhere to prescribed medications（OR=1.372,95%CI：1.078-1.666）, and serum 25-hydroxyvitamin D levels <30ng/ml（OR=1.369,95%CI：1.087-1.716） were independent risk factors for pneumonia in pulmonary tuberculosis patients (all P<0.05). Of the 156 pulmonary tuberculosis patients with pneumonia, 59 (37.82%) developed severe pneumonia. During the one-year follow-up, 14 of the 59 patients (23.73%) died. Among the pulmonary tuberculosis patients who died, the highest proportion (92.86%) had been on broad-spectrum antibiotics for 3 weeks or longer. Conclusion Patients with tuberculosis complicated by pneumonia are predominantly infected with Gram-negative bacteria. Risk factors for pneumonia development in tuberculosis patients include diabetes, hypertension, chronic bronchitis, prolonged use of broad-spectrum antibiotics (≥3 weeks), continuous corticosteroid therapy (≥2 weeks), disease duration ≥5 years, recurrent tuberculosis, malnutrition, non-compliance with medical instructions, and serum 25-hydroxyvitamin D levels <30 ng/ml. Among tuberculosis patients who developed pneumonia and died within one year, over 90% had sustained use of broad-spectrum antibiotics for ≥3 weeks. Therefore, clinical practice should prioritize rational administration of broad-spectrum antibiotics in such patients to reduce mortality risks.

Key words: Tuberculosis, Pneumonia, Risk factors, Distribution of pathogenic bacteria