Bacteriological Profile and Antibiogram of Respiratory Tract Infections in a Tertiary Care Hospital, Bangladesh

Background: Respiratory tract infections (RTIs) are significant health concern for mortality and morbidity in many developing countries. Proper identification of causative pathogens and their antibiotic susceptibility testing is needed to select appropriate antibiotic therapy for management of the patient suffering from RTI. The study was aimed to determine the spectrum of bacterial pathogen causing respiratory tract infections with their antibiogram in Dhaka Medical College hospital (DMCH), Dhaka, Bangladesh. Methods: This observational study was conducted from October 2018 to March 2019 in DMCH. Respiratory tract specimens (sputum, tracheal aspirate and throat swab) sent to the Microbiology laboratory for culture and sensitivity test were included in this study. Data regarding information of the patients, isolated organisms and sensitivity reports were collected from the records of the Microbiology laboratory. Results: Out of 580 processed specimens, 64.66% yielded significant growth of organisms of which 88.80% were gram negative and 11.20% were gram positive bacteria. Pseudomonas spp was the most commonly (31.47%) isolated organism followed by Klebsiella spp (23.47%), Escherichia coli (15.20%) and Staphylococcus aureus (8.53%). Gram negative bacteria were mostly resistant to amoxicillin followed by fluoroquinolones, cotrimoxazole, cephalosporins whereas colistin, carbapenems and piperacillin/tazobactum were the most sensitive antibiotics against them. Among gram negative bacteria, 31.23% were extended spectrum beta lactamase (ESBL) producing organisms and Klebsiella spp were the most commonly isolated ESBL producers. Majority of gram positive bacteria were resistant to fluoroquinolones and co-trimoxazole but all Staphylococcus aureus were susceptible to vancomycin and linezolid followed by teicoplanin (84%) and 37.5% of them were Methicillin resistant (MRSA). Conclusion: Gram negative bacteria were predominant where Pseudomonas spp and Klebsiella spp were most commonly isolated organisms. Most of the bacteria showed high resistance to commonly used antibiotics and this antimicrobial resistance is a matter of concern for the treatment of respiratory tract infections. Bangladesh Medical Res Counc Bull 2023; 49(1): 15-21