Received: August 28, 2026
Accepted for publication: September 24, 2026
Published online: September 30, 2026
UDC: 616.24-002.5:579.61:615.33.015.8
DOI: 10.26212/2227-1937.2026.39.16.008
MICROBIOLOGICAL MONITORING OF NON-SPECIFIC FLORA IN PATIENTS WITH TUBERCULOSIS
D.A. Kolekbay, G.B. Umutbayeva, О. А. Sidorenko
National Scientific Center of Phthisiopulmonology of the Ministry of Health of the Republic of Kazakhstan, Almaty, Kazakhstan
Introduction. Tuberculosis remains a major global health problem. In hospitalized patients with pulmonary tuberculosis, secondary bacterial flora may show substantial antimicrobial resistance, complicating treatment and underscoring the need for local microbiological surveillance.
Objective. To characterize the spectrum and antimicrobial resistance profiles of secondary bacterial flora in patients with pulmonary tuberculosis in Kazakhstan and to assess the association between levofloxacin-containing anti-tuberculosis regimens and fluoroquinolone resistance.
Materials and Methods. A retrospective cohort study was conducted using inpatient medical records from the National Scientific Center of Phthisiopulmonology of the Republic of Kazakhstan between 1 January 2021 and 30 September 2024. Seven hundred records were screened; 694 met the inclusion criteria and were included in the final analysis. Bacterial isolates were identified using VITEK 2, and antimicrobial susceptibility testing was interpreted according to CLSI 2023. Statistical analyses included χ² tests, the Cochran-Armitage trend test, and logistic regression; p<0.05 was considered statistically significant.
Results. Secondary bacterial flora was detected in 332 of 694 cases (47.8%). The most frequent isolates were Streptococcus pneumoniae (28.6%), Staphylococcus spp. (17.5%), Klebsiella pneumoniae (14.8%), and Pseudomonas aeruginosa (13.6%); 37.0% were nosocomial infections. Levofloxacin resistance in S. pneumoniae was 73% (69/95), while oxacillin resistance in S. aureus was 66% (21/32). In patients receiving levofloxacin-containing regimens, S. pneumoniae levofloxacin resistance was higher than in regimens without Lfx (37.5% vs 14.5%; adjusted OR 3.6, 95% CI 2.1 – 6.2; p<0.01).
Discussion. The findings indicate a high burden of resistant secondary bacterial isolates among hospitalized patients with tuberculosis and an association between levofloxacin-containing regimens and higher fluoroquinolone resistance. The retrospective observational design does not establish causality. Interpretation is limited by the single-center design, geographic imbalance, heterogeneous susceptibility panels, and the absence of molecular confirmation of resistance mechanisms.
Conclusion. A high frequency of antimicrobial-resistant secondary bacterial flora was observed in patients with pulmonary tuberculosis. The findings support regular local resistance surveillance, antimicrobial stewardship, and strengthened infection control. The association with levofloxacin-containing regimens requires confirmation in prospective studies with molecular characterization of resistance mechanisms.
Keywords: tuberculosis, drug resistance, bacterial, secondary infection, antibiotics, multidrug resistance.
