OCCURRENCE OF ESCHERICHIA COLI O157:H7 IN LACTATING COWS AND DAIRY FARM ENVIRONMENT AND ITS ANTIMICROBIAL SUSCEPTIBILITY PATTERN AT ADAMI TULU JIDO KOMBOLCHA DISTRICT, MID RIFT VALLEY, ETHIOPIA
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Date
2018-06
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Abstract
A cross sectional study was conducted from December 2017 to June 2018 on apparently healthy lactating cows at Adami Tulu Jido Kombolcha (ATJK) district in order to assess the occurrence of Escherichia coli O157:H7 in lactating cows and in dairy environment and to detect its antimicrobial resistance pattern. Total of 408 samples were collected and processed according to OIE terrestrial manual 2016. From 408 samples collected and processed, 19 were positive for E. coli O157:H7. The overall prevalence of E. coli O157:H7 was 4.7% (95% CI: 2.6; 6.7). Of 19 E.coli O157:H7 isolates, 4/50 were from water sample, 7/154 were from milk samples, 2/50 were from manure and 6/154 were from feces. The multivariable logistic regression indicate that, the prevalence of E. coli O157:H7 was significantly (p < 0.05) affected by factors such as area (urban, rural), floor type, cleaning of pens, milking location and hand washing during the time of milking. On the contrary, factors such as breed of the animal, herd size, use of towel and detergent, and history of mastitis did not show significant difference (p > 0.05). All 19 E.coli O157:H7 isolates were subjected to in vitro antimicrobial sensitivity test to ten commonly used antimicrobials. The test indicates varying degree of resistance; 100% resistance was observed for Ampicillin, Cephalothin and Rifampin and 100% susceptibility was observed for chloramphenicol, ciprofloxacin, gentamicin, nalidixic acid, kanamycin and tetracycline. With regard to streptomycin, 63.15% of the isolates were susceptible and 36.8% were intermediate. All 19 E.coli O157:H7 isolates showed the presence of multidrug resistance. In conclusion, the occurrence of E. coli O157:H7 was observed both in lactating cows (milk and feces) and dairy farm environment (manure and water) sustaining a continuous transmission of the bacterial. The development of multidrug resistance could hamper the control and prevention effort. Therefore, strict control measures such as treatment of positive cases using effective drugs and prevention measures such as strict hygiene practices should be established, including cleaning of floor, pens and milking barns as well as proper hand cleaning.
Description
A Thesis Submitted to the College of Veterinary Medicine and Agriculture of Addis Ababa University in Partial Fulfillment of the Requirements for the Degree of Master
of Science in Tropical Veterinary Epidemiology
Keywords
Occurrence, Lactating cows,, E. coli O157:H7