Drug sensitivity pattern of <i>Escherichia coli</i> isolated from samples of different biological and environmental sources

Abstract

A total of 100 different E. coli isolates collected from 10 different biological and environmental sources (10 isolates from each source) such as human faces, human urine, cattle, sheep, goat, chicken, duck, pigeon, drain sewage and soil were used for in-vitro drug sensitivity test in the Department of Microbiology and Hygiene, Bangladesh Agricultural University, Mymensingh during the period from January to May 2007. Ten different drugs such as Gentamicin (GM), Azithromycin (AZM), Erythromycin (E), Levofloxacin (LVX), Ciprofloxacin (CIP), Tetracycline (TE), Amoxicillin (A), Ampicillin (AP), Nalidixic acid (NA) and Metronidazole (MET) were used in this study. Sensitivity test was carried out by the Kirby-Bauer disc diffusion method as per recommendation of National Committee for Clinical Laboratory Standards and efficacy of a drug was determined by measuring the diameter of the zone of inhibition that results from diffusion of the agent in to the medium surrounding the disc. A high of 80% and 78% E. coli isolates collectively from all the selected sources were sensitive to LVX and CIP respectively, followed by GM (46%), AZM (45%), TE (30%), AP (29%), E (19%), NA (18%) and A (15%). No isolate was sensitive to MET (0%). Incase of resistance, 96% isolates were resistant to MET, followed by A (72%), E (69%), NA (67%), TE (60%), AP (59%), AZM (33%) and GM (32%), CIP (8%) and LVX (5%). A number of isolates showed intermediate reaction to GM (22%), AZM (22%), LVX (15%), NA (15%), CIP (14%), A(13%), AP (12%), E (12%), TE (10%) and MET (4%). This may be an intermediate phase for the conversion of E. coli isolates from sensitive to resistant form. From the research it may be concluded that E. coli infection of different animals and birds and also of human being may be treated effectively with LVX and CIP followed by GM and AZM.

Key words: E. coli isolates, levofloxacin, ciprofloxacin, efficacy, resistance

DOI = 10.3329/bjvm.v6i1.1332

Bangl. J. Vet. Med. (2008). 6 (1): 13-18