Antibiotic susceptibility profile of bacterial isolates from clinical specimens in a tertiary care hospital in Dhaka, Bangladesh

Background: On a global scale, bacterial infections are the second leading cause of death, heightening health care expenditures every year. The exaggerated antibiotic administration has led to the selection of new strains which resist antimicrobial agents. Therefore, we paid attention to determine antibiogram profile of the bacterial isolates from different clinical samples against various classes of antibiotics in Bangladesh. Methods: Six hundred and twenty six clinical specimens were collected from suspected patients with different symptoms of bacterial infections, aged below 20 years to above 60 years, attended in a tertiary care hospital in Dhaka city. Of 626 samples, we identified 111 (18%) strains of eight bacterial species by standard microbiological methods. Antibiotic sensitivity of the isolates were done by Kirby-Bauer disc diffusion technique. Results: Older adults (above 60 years) are more prone to bacterial infections where the prevalence rate was 36% (n=40) compared to patients under 20 years (9.9%, n=11). Moreover, women (72.1%, n=80) are more susceptible to infectious diseases than male counterparts (27.9%, n=31). The most common causative agent of infection was a gram-negative pathogen, E. coli (29.7%, n=33) whereas a gram-positive bacteria, Enterococcus spp. (22.5%, n=25) was in the second position. Two carbapenems (imipenem and meropenem) were highly effective (sensitivity rate 75-100%) against most of the gram-negative isolates and amoxicillin was less effective (resistance rate 72-81%). In case of gram-positive bacteria, the isolates exposed highest sensitivity against a beta-lactam antibiotic, piperacillin/tozabactam (92%), followed by co-trimoxazole (85-88%) and netilmicin (85%) whereas they showed low to moderate resistance to other antibiotics tested. Conclusion: This study highlights the prevalence rate of clinical pathogens and their drug sensitivity patterns against routinely used antibiotics in a hospital setting which is crucial for guiding clinicians in proceeding effective treatment of bacterial infections.