Antimicrobial Susceptibility Profile of Salmonella, and Escherichia Coli K99 from Diarrheic Calves in and Around Awash Fentale District of Afar Region, Eastern Ethiopia
Authors: Yosef Dek Kahin ,   Habtamu Girma Tegenaw2, Adem Abdiaziz Ali 
Published: January 2024

Background
The global community is confronted with a significant challenge in the form of antimicrobial resistance, which affects both public and animal health. This phenomenon is greatly influenced by the widespread use of antimicrobial agents in various domains, including human medicine, veterinary practices, and other sectors. The increasing prevalence of drug resistance in E. coli and Salmonella spp. strains isolated from humans and animals has sparked a vigorous debate concerning the potential risks to public health associated with the utilization of antibiotics in animal production. Hence, the objective of this research was to assess the susceptibility of Salmonella enterica to antimicrobial agents and to detect the presence of Escherichia Coli K99 in diarrheic calves within the Awash Fentale District of the Afar Region, in Eastern Ethiopia.
Objectives
To assess antimicrobial susceptibility profile of Salmonella enterica, and to identify Escherichia Coli K99 from Diarrheic Calves in and Around Awash Fentale District of Afar Region, Eastern Ethiopia
Methods
The current cross-sectional study was conducted from December 2022 to November 2023 with the aim to isolate and identify E. coli K99 and Salmonella enterica and associated risk factors for occurrence of these two pathogens. Fecal samples were collected from a total of 188 diarrheic calves aged up to 6 months from 150 households in Awash Fentale district Afar region, eastern Ethiopia. The samples were transported in ice box to Aklilu Lemma Institute of Pathobiology laboratory, microbiology department for isolation and identification of bacteria. Feces were stored at 4°C until the time of processing. These samples were processed during the study period for the isolation and identification of E.coli K99 and Salmonella enterica using culture media, biochemical tests, Pathasure kit and Biolog GEN III microplate. Data after laboratory test result was recorded in Microsoft excel® 2021 from prepared result recording format paper. The data was then imported to the software STATA windows version 14 (StataCorp LP, College Station, Texas, USA) for appropriate statistical analysis. Pearson Chi-square (X2) test followed by multivariable logistic regression analysis was utilized to assess the degree of association between each risk factor and calf diarrhea causing E.coli K99 and Salmonella enterica. An association was regarded as significant if the p-value is < 0.05.
Result
Out of 188 samples, 20.74% and 5.32% were found to be positive for E.coli K99 and Salmonella enterica respectively. Antimicrobial sensitivity patterns of Salmonella enterica were also investigated using 12 commonly used antibiotics. All isolates from calves were susceptible (100%) to amikacin, chloramphenicol, ampicillin, amoxicillin + clavulanic acid, ceftriaxone, cephalothin ciprofloxacin, tetracycline, gentamycin and trimethoprim + sulfamethoxazole. Multivariable logistic regression analysis was done to identify significant risk factors associated with examined bacteria. Thus, study showed that the occurrence of E. coli K99 in male calves was higher (25.27%) than in female calves (16.49%). This might be the reason that more care is given to female calves than male calves. Because female calves are needed by the pastoralist were compared with male calves for milk production. On the other hand, age and colostrum feeding within 24 hours were significantly associated with Salmonella enterica shedding. Calf age was significantly associated with Salmonella enterica (P = 0.014, OR = 13.15, 95% CI = 1.677-103.127). The highest occurrence of Salmonella enterica was recorded in the 61–120 days of age (13.79%) than 1–60 days of age (2.86%) and 121–180 days of age (10.53%) diarrheic calves.
Conclusion
The isolation and identification of bacteria, as well as the assessment of risk factors linked to the transmission of bacteria causing diarrhea, can prove beneficial in developing effective strategies for prevention and control.