Spectrum of Bacterial and Fungal Co-infections in Sputum Smear-Positive Pulmonary Tuberculosis: A Cross-Sectional Study from a Tertiary Care Centre in Northern India

Background Pulmonary tuberculosis remains a significant global health burden, particularly in developing countries. Bacterial and fungal co-infections complicate clinical outcomes and increase mortality; however, comprehensive data from northern India are limited. This study aimed to analyze the spectrum of bacterial and fungal co-infections in sputum smear-positive pulmonary tuberculosis patients. Methods This cross-sectional study enrolled 100 consecutive sputum smear-positive pulmonary tuberculosis patients aged > 18 years at a tertiary care center in Haryana, India. Sputum samples underwent Gram staining, bacterial culture on blood agar and MacConkey agar, potassium hydroxide mount, and fungal culture on Sabouraud dextrose agar. Demographic, clinical, radiological, and laboratory parameters were analyzed using chi-square tests, Mann-Whitney U tests, and multivariate logistic regression. Results The mean age was 45.4 ± 16.4 years with male predominance (67%). Bacterial co-infection was documented in 50% of patients, with Pseudomonas aeruginosa (19%), Klebsiella pneumoniae (10%), and Staphylococcus aureus (9%) predominating. Fungal co-infection occurred in 18%, predominantly Candida species (15%). Gram-negative organisms constituted 69% of bacterial isolates. Elevated total leukocyte count independently predicted bacterial co-infection (p = 0.008). Diabetes mellitus demonstrated strong association with fungal co-infection (OR = 3.14, p = 0.055), while hemoptysis was significantly associated with fungal co-infection (p < 0.001). Conclusions Bacterial and fungal co-infections are highly prevalent in sputum smear-positive pulmonary tuberculosis patients. Routine microbiological screening, particularly in patients with leukocytosis, diabetes, or hemoptysis, may facilitate early detection and appropriate management, potentially improving treatment outcomes.