Prevalence and antibiotic susceptibility pattern of Escherichia coli in cattle on Bathan and intensive rearing system

The aim of this longitudinal study was to verify the prevalence and antibiotic susceptibility pattern of Escherichia coli (E. coli) in cattle reared on Bathan and intensive farming system in Bangladesh. Fecal materials originated from recto anal junction (RAJ) of 100 cattle used for primary screening on MacConkey agar. The diversities among the pink color colony producing isolates on MacConkey agar were verified by conventional cultural methods and biochemical tests. Phenotypically positive E. coli isolates were further investigated for the variations in the antimicrobial resistance profiles to 10 selected antibiotics, by the disk-diffusion method. This study revealed that the overall prevalence of E. coli was 70% of in the rectal swab sample of cattle. However, the prevalence of E. coli was found significantly higher (p= 0.002) in cattle under intensive farming (84%) than cattle on Bathan (56%). Antibiotic susceptibility pattern shows that among the tested isolates 83%, 73%, 68% and 64% were sensitive to chloramphenicol, gentamicin, ciprofloxacin and ampicillin, respectively. On the other hand, all the 70 (100%) E. coli isolates were found resistant to tetracycline and sulfamethoxazole. A high antibiotic resistance profile was also found against amoxicillin (90%), ampicillin (87%), nalidixic acid (86%) and erythromycin (83%). In total, 24 (34%) isolates were resistant against ?2 antimicrobials. The result clearly shows that antibiotic resistant E. coli isolates are commonly present in cattle of different management systems (intensive and Bathan). Therefore, careful selection of appropriate antibiotics with optimal doses might be ensured to prevent the emergence of antibiotic resistance bacteria. Microbes and Health, June 2017, 6(1): 1-4