Antibiotic resistance profile of Escherichia coli isolates from colibacillosis in and around Pantnagar, India.

Aim: The present study was designed to study antibiotic resistance profile of E. coli isolates from colibacillosis in layers in and around Pantnagar. Materials and Methods: A total of 20 isolates of E. coli were recovered from 35 cases of colibacillosis in layers during necropsy. Antibiogram was studied via disc diffusion method against 12 antibiotics. Results: Results showed multiple drug resistance in 52.63% E. coli isolates. Serotyping of these isolates revealed 10 'O' group serotypes, predominantly O80 and O84 accounting for 31.57%. O80, O110, O119 and O132 have previously been isolated from human suggesting its zoonotic importance. A high degree of resistance was seen against cephalexin (73.68%) whereas chloramphenicol was found to be maximally (100%) effective. Emergence of enhanced mechanism of resistance to a variety of frequently used antibiotics is an increasing public health problem. Conclusion: It can be concluded that animals and human are at potential risk of acquiring infection with multi drug resistant strain of E. coli.


Introduction
its transmission to human pathogens is important because these resistant bacteria may colonize the E. coli has become a great concern in both human human intestinal tract and may contribute resistance and veterinary practices.Although ubiquitous in nature, genes to human endogenous microflora through Rit plays a vital role in maintaining homeostasis of intestinal factor, conjugative plasmid, or chromosomal elements physiology of poultry [1].It is not detrimental as long as reviewed by Kabir [9].Therefore, disease-causing as it is kept in check by other intestinal microflora [2] microbes that have become resistant to antibiotic drug but whenever there is imbalance, it results in colibacillosis, a therapy are an increasing public health problem.disease of severe economic significance to all poultry Due to the significance of E. coli infection in producers, worldwide, characterized by a diverse array poultry industry, the present study was envisaged with of lesions [3,4].This disease is of immense zoonotic the objectives of isolation of E. coli from various importance since poultry meat is the commonest source poultry samples and to study their antibiotic resistance of animal protein consumed by human population in pattern against wider range of antibiotics.most parts of the world [5].There is increase in both incidence and severity of colibacillosis and current Materials and Methods trends indicate that it is likely to continue and become Collection of samples: A total of 35 faecal and an even greater problem in the poultry industry [6].
carcass samples were collected using sterile cotton Now, there is considerable increase in prevalence of swab (Himedia, India), under strict aseptic condition, this disease in layers indicative of an alarming situation from morbid white leg horn birds of varied age groups [7].
(0 to 6 weeks of age) that were brought to Department Antibiotics are extensively used in poultry industry of Veterinary Microbiology from areas in and around either as a growth promoter or to control infectious Pantnagar.Sampling were made as per the guidelines diseases [8].Concern about antibiotic resistance and of Institutional Animal Ethics Committee.Samples furazolidone (50 µg/disc), enrofloxacin (10 µg/disc) were collected based on clinical findings and and co-trimoxazole (25 µg/disc).pathognomonic lesions observed during necropsy.

Transportation of sample: After collection, all the
In the present study, E. coli were recovered from samples were being transported to the laboratory and 20 (57.14%) samples out of 35 samples collected.20 processed immediately.
Antibiotic susceptibility pattern of E. coli isolate from poultry samples has been outlined in Table -1.It Serotyping: The isolates were sent to National was observed that chloramphenicol was 100 % Salmonella and Escherichia centre, Kasauli, sensitive followed by sulphamethizole, co-trimoxazole Himanchal Pradesh, India for further confirmation and (84.21% each) and amikacin (78.95%).This finding is 'O' group serotyping.
in agreement to earlier studies done by other workers.Antibiotic susceptibility testing: Antibiogram of Akond et al [8] and Sharada et al [14] showed that various serotypes was prepared using disc diffusion chloramphenicol is 80% effective against E. coli method, as described by Cruickshank et al. [10], isolated from poultry and poultry environment.Alam against 12 commonly used antibiotics.The results et al [16] found that E. coli isolated from layers were were interpreted according to the criteria recommensensitive to chloramphenicol.Omer et al [7] reported ded by National Committee for Clinical Laboratory that E. coli isolated from colibacillosis are highly Standards (NCCLS) [11].The antibiotic discs used in sensitive to co-trimoxazole which is in support to our this study were amikacin (30 µg/disc), cephalexin (30 findings.Mitra et al [9] showed that amikacin can be µg/disc), cephotaxime (30 µg/disc), chloramphenicol an effective drug in controlling poultry colibacillosis.(30 µg/disc), sulphamethizole (300 µg/disc), However, in contrast, Rahman et al [17] reported nitrofurantoin (300 µg/disc), norfloxacin (10 µg/disc), resistance against chloramphenicol whereas Sharada pefloxacin (5 µg/disc), neomycin (30 µg/disc), et al [14] showed a high level resistance to co-  [19] showed poultry as a reservoir of third-generation cephalosporin-resistant E. coli.Enrofloxacin was the

Table - 1. Antibiotic susceptibility pattern of E. coli isolate from poultry samples trimoxazole
(76.92%).A high degree of resistance was of Agriculture and Technology, Pantnagar for found to be against cephalexin (73.68%) followed by providing necessary facilities and to the Director, neomycin and enrofloxacin (31.58% each) which is in National Salmonella and Escherichia Centre, Kasauli, full agreement withSharada et al [14].Nath et al[18]for serotyping.alsoshowedresistance against cephixime in Competing interests significant portion of the E. coli isolates.Wasyl et alAuthors declare that they have no competing interests.