Abstract: Objective Based on the BS1000 fully automatic Mycobacterium tuberculosis culture instrument and a combination of multiple technologies, this study explored the positive detection rate of Mycobacterium tuberculosis in 576 pleural effusion samples, and applied the minimum inhibitory concentration(MIC) method to determine the sensitivity of 14 anti-tuberculosis drugs, thereby providing a scientific basis for clinical practice. Method The BS1000 fully automatic Mycobacterium tuberculosis culture instrument was used to culture and detect 576 samples of pleural effusion clinically submitted for examination between January and December 2024 at the Chest Hospital of Guangxi Zhuang Autonomous Region. After the acid-fast bacilli in the positive culture samples were confirmed using intelligent scanning and optimized staining technology, the strains were identified through antigen detection and the traditional p-nitrobenzoic acid (PNB) method. The MIC method was used to detect the sensitivity of 14 anti-tuberculosis drugs for the Mycobacterium tuberculosis isolates, and the detection rate and drug-resistance characteristics of Mycobacterium tuberculosis were statistically analyzed. Result Mycobacterium tuberculosis strains were isolated from 88 of the 576 pleural effusion samples, with a detection rate of 15.5% (88/576). There was a statistically significant difference was observed in the positive rate of Mycobacterium tuberculosis culture in pleural effusion among patients with different clinical diagnoses (χ2=25.6, P=0.001). The highest positive rate was observed in patients with pulmonary shadows (22.6%), while the positive rates were relatively low among patients with diseases such as lung cancer (5.3%) and extrapulmonary tuberculosis (5.5%). The total drug resistance rate of 88 Mycobacterium tuberculosis strains was 21.6% (19/88). The drug resistance rate to streptomycin was the highest (7.9%), and no drug-resistant strains were detected against six drugs including ethambutol and rifabutin. Among first-line drugs, no resistant strains were detected for ethambutol; among second-line drugs, no resistant strains were detected for levofloxacin, amikacin, and multi-drug resistance was mainly characterized by streptomycin inclusion. Conclusion The detection rate of Mycobacterium tuberculosis in pleural effusion was associated with clinical diagnosis. In clinical practice, drugs should be selected according to the disease condition and drug-resistance characteristics, and personalized treatment plans should be developed. In addition, the monitoring of high-risk drugs such as streptomycin should be strengthened.

Key words: Pleural effusion, Mycobacterium tuberculosis, Multiple technologies, Detection rate, Drug resistance rate