A STUDY ON CLINICAL SIGNIFICANCE OF MORAXELLA CATARRHALIS IN CAUSING LOWER RESPIRATORY TRACT INFECTIONS IN ADULTS AND THEIR ANTIMICROBIAL USCEPTIBILITY PATTERN IN A TERTIARY CARE HOSPITAL

Background of the study - Moraxella catarrhalis ,has now emerged as a pathogen and is now considered as an important cause of lower respiratory tract infection ,particularly in adults with chronic obstructive pulmonary disease. Aim of the study - To evaluate the significance of Moraxella catarrhalis as a pathogen in causing lower respiratory tract infections, to assess the risk factors and to determine the antibiotic susceptibility pattern of Moraxella catarrhalis. Materials and Methods This cross sectional study was conducted at the Institute of Microbiology over a period of 6 months at Madras Medical College, Chennai. A total of 620 sputum samples were collected and processed from patients with suspected to be suffering from lower respiratory tract infection. The sputum samples were subjected to Gram staining, bacterial culture and antimicrobial susceptibility testing of the isolates. Moraxella catarrhalis was identified based on the cultural characteristics and identified with the relevant biochemical reactions. The antimicrobial susceptibility testing of Moraxella catarrhalis was performed by Kirby Bauer Disc Diffusion method. Result Among 620 samples, the isolation rate of Moraxella catarrhalis was 9.35percentage and was more commonly seen in the age group of 50 and 50 years. Rate of isolation of Moraxella catarrhalis was higher in males(62.06percentage) than in females (37.93percentage).95.24 percentage of the isolates were susceptible to amoxicillin clavulanic acid and 17.24percentage sensitive to ampicillin only. Conclusion Isolation of Moraxella catarrhalis in the sputum sample from patients above 50 years of age , in the absence of other well established pathogen should not be disregarded, as they can cause lower respiratory tract infection in these individuals.