Study on Occurance, Distribution and Antibiotic Sensitivity Pattern of Gram Positive and Gram Negative Bacteria among Suspected Lower Respiratory Tract Infection Patients Visiting Bir Hospital

Abstract

Lower respiratory tract infections (LRTI) are common causes of morbidity and mortality worldwide. It was a prospective study carried out at Bir Hospital, Kathmandu from 15th April, 2010 - 14th July, 2010. This study comprised of 214 patients (93 in-patients and 121 out-patients). Sputum samples of 214 patients were collected and subjected to gram staining, bacterial culture and antibiotic sensitivity for bacterial isolates as per standard techniques. Pathogenic organisms were isolated from 97 out of 214 cases (45.32%). Growth of pathogens were obtained from 45.16% of sputum samples in case of in-patients and 45.45% in out-patients. The maximum numbers of patients (52.34%) were above 50 years of age. Sex-wise distribution showed 61 (62.89% of the positive cases) males as compare to 36 (37.11%) females. Gram negative bacteria (65.98%) outnumbered the growth of Gram positive bacteria. The commonest organisms isolated were Klebsiella pneumoniae (24.74%) followed by Staphylococcus aureus (18.56%). From hospitalized patients, K. pneumoniae (62.5%) was the most common pathogen isolated whereas S. aureus (61.11%) was the second predominant organism. Single organism was isolated in most of the samples 92.78% (90/97) but in 7.22% cases (7/42) confluent growth of two organisms were observed. Incidence of Haemophilus influenzae and Streptococcus pneumoniae was found low in our study. Gram negative bacteria were found most susceptible to Chloramphenicol (100%), Levofloxacin (100%) followed by Ciprofloxacin (82.81%), Gentamicin (76.56%), Amikacin (74.58%) and Cefotaxime (64.06%). They were least susceptible to Cotrimoxazole (37.5%), Cephalexin (34.38%) and Ampicillin (18.75%). Gram positive bacteria were found most susceptible to Ciprofloxacin (84.85%) followed by Cloxacillin (75%), Erythromycin (69.70%), Cephalexin (66.67%) and Ampicillin (63.64%). They were least susceptible to Cotrimoxozole (37.5%). Incidence of MDR was 72.22% in S. aureus and 22.22% in β-haemolytic streptococci. Among GNB all the isolates of C. freundii and E. coli were MDR whereas 75% of K. oxytoca, 58.33% of K. pneumoniae followed by 55.56% of P. aeruginosa and 44.44 % of Acinetobacter spp. were MDR.