Investigation of Pathogenic <i>Escherichia Coli</i> from Diarrheic Calves in Selective Area of Bangladesh
DOI:
https://doi.org/10.3329/bjvm.v13i1.23716Keywords:
Prevalence, polymerase chain reaction, virulence genes, antibiotic sensitivity, atypical EPECAbstract
Molecular technique was used to investigate the prevalence of virulent diarrheic genes in pathogenic Escherichia coli and their antibiotic sensitivity patterns. A hundred samples from 100 different diarrheic calves from mid-north-western part of Bangladesh were screened for the presence of virulence factors associated with diarrhea. Following isolation and identification on the basis of cultural, morphological and biochemical properties, the presence of the virulence genes such as eaeA, bfpA, elt, est, stx1 and stx2 were examined using PCR. Antimicrobial susceptibility of 57 E. coli was determined by agar disk diffusion method for 8 antimicrobial agents. Out of 100 samples 57 (57%) were found to be positive for E. coli and their distribution rates according to their age, breed and sex were 66.7% ( 6 days old ), 85.7% (Sahiwal breed) and in 64.2 % (female calves) respectively. Among 57 E. coli isolates, only 16 isolates were analyzed for the detection of the said genes. Among them, only eaeA gene was detected in 2 E. coli isolates (12.5 %). Antibiotic resistance patterns revealed that Oxacillin, Rifampicin and Penicillin were 100% resistant followed by Erythromycin which was more than 80% resistant. In case of Amoxicillin and Tetracycline, about 59.65% and 61.40% were found to be resistant respectively whereas all 57 E. coli isolates showed moderately susceptible (30%) to Cefuroxime, a second generation Cephalosporin. Therefore, none of the eight antimicrobials studied can not be recommended as single best therapeutic agent for the treatment of neonatal calf diarrhea. In addition, this study indicated that diarrhea in calves in these locations can be ascribed to mainly Enteropathogenic E. coli (EPEC) which was atypical (only contained the eaeA genes but not bfpA). However, further studies are necessary to characterize the isolated eaeA gene positive E. coli by serotyping, tissue culture assay and other molecular techniques to find out the potentiality of those virulent genes contributing pathogenicity of E. coli causing diarrhea in calves.
DOI: http://dx.doi.org/10.3329/bjvm.v13i1.23716
Bangl. J. Vet. Med. (2015). 13 (1): 45-51
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