Abstract:
A cross-sectional study was conducted from November, 2019 to June, 2020 to assess the
occurrence and antimicrobial susceptibility patterns of E. coli O157 and Salmonella in raw
cow milk collected from smallholder milk producers, dairy farms, milk collection centers and
cafeterias in and around Bahir Dar city, Ethiopia. Samples were collected using a simple
random sampling technique and analyzed using the recommended standard procedures to
isolate and identify the pathogen. Additionally, a structured questionnaire survey was
conducted to assess the status of hygienic practices in the smallholder milk producers, dairy
farms, milk collection centers and cafeterias. The data was processed and analyzed by using
SPSS version 20.0 software. Descriptive statistical analysis such as percentage, chi-square
and fishery exact test of various risk factor and dependent variables. Out of 150 raw milk
samples, 70 smallholder milk producers, 29 dairy farms, 35 milk collection centers and 16
cafeterias examined.The occurrence rate E. coli O157 and Salmonella was 9 (6%) and
7(4.7%), respectively. The occurrence of E. coli O157 was highest in smallholder milk
producers (7.15). While, lowest in dairy farms (3.4). Similarly, the occurrence of Salmonella
was highest in cafeteria (6.3%). While, lowest in dairy farms (3.4%). The antimicrobial
susceptibility profile showed that all isolates were 100% susceptible to Gentamicin and
Ciprofloxacin, and resistant to Ampicillin. While,11% of E. coli O157 and 42.9 % of
Salmonella isolates were found to be multidrug resistance. Physicians within the area should
consider Ciprofloxacin and Gentamicin as first choice drugs within the treatment of clinical
diseases associated with Escherichia coli O157 and Salmonella. It is recommended training
should be provided on hygienic practices for the stakeholders involved in the milk value
chain, and therefore the proper pasteurization of milk to maintain the safety and quality of
milk for consumers in the area.
Keywords: Antimicrobial resistance, Milk, Occurrence, Escherichia coli O157, Salmonella, H
ygienic practice