Aerobic Bacteriological Study of Acute Exacerbations of Chronic Obstructive Pulmonary Disease

The natural history of chronic obstructive pulmonary disease is characterized by frequent exacerbations. Majority of exacerbations are infectious and bacteria responsible for 30-50% of these cases. The purpose of this study was to determine the bacteriology of acute exacerbations of chronic obstructive pulmonary disease in hospitalized patients in our institution and their antibiotic susceptibility pattern to formulate cost effective antibiotic strategy and reducing the emergence of drug resistance.

One hundred and seven clinically diagnosed cases of acute exacerbations of chronic obstructive pulmonary disease admitted in medicine, tuberculosis and chest wards were selected for the study. Direct gram stain was done for all sputum samples. The suitable sputum samples were cultured. Identification of organism and antimicrobial susceptibility testing was done by standard microbiological techniques.

Our study showed growth of pathogenic organisms in 41.12% cases. Males (67.29%) are more affected than females (32.71%). Gram negative bacilli were more isolated than gram positive cocci. The commonest isolate was Klebsiella pneumoniae 15 (38.46%), followed by Staphylococcus aureus 9 (23.08%), Streptococcus species 6 (15.39%), Pseudomonas aeruginosa 4 (10.26%), E.coli 2 (5.13%), Acinetobacter species 2 (5.13%) and Enterobacter species 1(2.56%). The antibiotic susceptibility reveals that vancomycin, linezolid, azithromycin and clarithromycin were most effective drugs for gram positive cocci, meropenem & piperacillin-tazobactam for gram negative bacilli and amikacin & levofloxacin for both gram positive cocci & gram negative bacilli.

In developing country like India acute exacerbations of chronic obstructive pulmonary disease is common in adults more than 50 years of age due to smoking habits and high indoor pollution. This leads to a major impact on the quality of life of patients with the condition. They are a major cause of hospital admission and health care utilization.