Department of Microbiology, College of Veterinary Science, Rajendranagar, Hyderabad-500 030 (AP).
* Part of M.V.Sc. thesis of first author submitted to A.N.G. Ranga Agricultural University, Hyderabad.
An investigation was carried out to characterize fifty-one E. coli isolates of chicken origin with regard to their serogroup and antibiotic resistance pattern. The serogroups identified among E. coli isolates were 020, 054, 061, 073, 078, 088, 089, 0111, 0115, 0119, 0132 and 0153. Predominant serogroups were 078 (23.5%) and 0115 (14%). Twenty seven per cent of the isolates were rough. The identification of new serogroups such as 020, 054, 061, 073, 088, 0 111, 0115, 0119 and 0132 indicate the emergence of new serogroups associated with avian colibacillosis. E. coli isolates were tested against 12 antibiotics for their resistance pattern. The resistance frequencies were oxytetracycline (78.43%), doxycline (58.10%), kanamycin (58.86%), co-trimaxozole (52.94%), ciprofloxacin (50.98%), streptomycin (45.10%), amoxycillin (41.18%), pefloxacin (35.29%), enrofloxacin (33.33%), gentamicin (25.49%), cephalexin (21.57%) and chloramphenicol (3.92%).
Chicken, E. coli, serogroups, antibiogram
