Antimicrobial resistance dynamics in Mycobacterium tuberculosis coinfection systems: A spatiotemporal strain analysis

Secondary pulmonary infections are crucial and pivotal contributing factors to clinical deterioration in patients with pulmonary tuberculosis. Research remains limited regarding the specific population and regional epidemiology of these secondary infections, despite its clinical importance. This study provides an in-depth analysis of the primary bacterial pathogens and their antimicrobial resistance rates among hospitalized pulmonary tuberculosis patients with concurrent pulmonary infections in Yangzhou, China, from 2021 to 2024. Suitable sputum samples and leftover bronchoalveolar lavage fluid samples were collected for bacterial culture identification and drug sensitivity testing. The annual and regional distributions of strains and the evolution of resistance rates were analyzed using the chi-square test and the Cochran-Armitage trend test. A total of 514 strains of pathogenic bacteria were cultured from 410 samples, with 499 strains (97.08 %) being Gram-negative bacteria. Klebsiella pneumoniae was the most common Gram-negative bacterium (40.27 %), followed by Pseudomonas aeruginosa (15.18 %), while Staphylococcus aureus was the primary Gram-positive bacterium (1.75 %). The drug sensitivity tests results over different years showed that K. pneumoniae exhibited significant resistance rates against doxycycline, ceftazidime, cefepime, cefuroxime, cefazolin, cefotaxime, levofloxacin, ticarcillin/clavulanate, amikacin, and norfloxacin (P < 0.05). The resistance rates of P. aeruginosa to cefazolin and ciprofloxacin were also statistically significant (P < 0.05). The drug sensitivity test results across different regions showed that the resistance rate of K. pneumoniae to minocycline in urban patients was statistically significant (P = 0.012), while the resistance rates of P. aeruginosa to tobramycin and ciprofloxacin in rural patients were statistically significant (P < 0.05). Annual statistics of extended-spectrum beta-lactamase ESBL-producing K. pneumoniae resistant strains showed significant annual increases (P < 0.05). Moreover, data on resistant strains in urban and rural areas indicated that the detection rate of ESBL-producing Escherichia coli in rural areas was higher than that in urban areas (P = 0.052), and the detection rate of ESBL-producing K. pneumoniae resistant strains in rural areas was significantly higher than in urban areas (P = 0.005). The rise of new carbapenem-resistant K. pneumoniae strains in 2023 should be monitored. This study provides strong data support to formulate antibiotic treatment plans for patients with tuberculosis and respiratory infections, reduce the risk of resistant strain transmission, and optimize clinical treatment strategies.