The Emergence and Importance of Moraxella Catarrhalis as Human Respiratory Tract Pathogen and its Antibiogram

Background: Moraxella catarrhalis is a Gram-negative diplococcus, commonly found as a normal flora in the human upper respiratory tract.Recently, M. catarrhalis has emerged as an important human pathogen in respiratory tract.Aims and Objectives: The present study was conducted to isolate M.catarrhalis as potential pathogen of respiratory system and to determine the prevalence with underlying risk factors as well as to establish a proper antibiogram.Methods: A prospective study of 1250of respiratory specimens, were carried out over a two years' tenure.The identification was done by microscopic examination, culture characteristics, an array of biochemical reaction and Vitek 2 system.The antibiotic sensitivity test was carried out according to the Kirby -Bauer disc diffusion method and their zone size interpretation was carried out by National Committee for Clinical Laboratory Studies (NCCLS) guidelines.Results: A total of 33 clinically significant M. Catarrhalis were isolated from the 372 culture positive samples.Most of the isolates were obtained from the patients who were diagnosed as pneumonia (39.39%).Moraxella cattarahalis showed good sensitivity to almost all commonly used antibiotics such as Aminoglycosides (96.29%),Amoxycillinclavulanic acid (93.11%),Ampicillin (92.59%) and Azithromycin (92.59%).Conclusion: Moraxella catarrhalis should be considered as significant emerging respiratory tract pathogen especially in elderly patients with underlying risk factors like diabetics mellitus.