Background Susceptibility of microorganisms to antibiotics is clearly decreasing in many Asian countries and is of particular concern in Streptococcus pneumoniae. The genetic relationship between penicillin-resistant S pneumoniae strains from across Asia suggests that resistant clones have spread within and between countries.

Purpose The study was designed to determine the susceptibility of respiratory microorganisms to antibiotics by using antibiogram reports.

Materials and methods The bacterial strains were isolated from patients suffering from respiratory tract infections (sputum, bronchial wash and throat swab, pleural fluids). Patients with respiratory tract infections having antibiogram were collected retrospectively and prospectively from the patient records and microbiology laboratory respectively. 147 subjects whose antibiogram reports available were included in the study.

Results The duration of stay in hospital varied among the population. In the retrospective study most of the patients (37.27%) were admitted for 6–10 days while 25.45% stayed for 1–5 days. In prospective study, most of the patients (37.83%) had a hospital stay of 6–10 days while 27.02% were admitted for 1–5 days. Due to increased resistance shown by previously susceptible organisms patients were at a risk of longer hospital stays. In retrospective phase, most of the patients received more than one antibiotic as part of the treatment. 34.54% patients were on two antibiotics while 25.45% were on three antibiotics. In the prospective study, the number of patients receiving only one antibiotic was high (43.24%), while 32.43% were on three antibiotics. The susceptibility of microorganisms was more evident in hospitals where the antibiotic usage is maximum. Hence pathogenic microorganisms can now defy antibiotics to which they were previously susceptible.

Conclusions The study emphasises that, antibiotic susceptibility testing should be carried out for all the patients who is in need of antibiotic therapy. Because of the immediate unavailability of antibiogram report it is better to obtain gram stain report before starting empirical therapy. Thereby it helps in choosing appropriate antibiotics having a narrow spectrum of activity. After obtaining the antibiogram report the sensitivity of the empirically started antibiotic should be checked against the same. Moreover the patient should be cautioned to follow the correct therapeutic regimen even after getting discharged from the hospital.