ISOLATION, ANTIBIOGRAM AND ASSOCIATED RISK FACTORS OF NON- TYPHOIDAL SALMONELLA FROM APPARENTLY HEALTHY AND DIARRHEIC SHEEP IN MAYA CITY, EASTERN ETHIOPIA

Abstract

Salmonellosis represents an important human and animal pathogen. A cross-sectional study was conducted from February to August 2023 to estimate the prevalence of non-typhoidal Salmonella from apparently healthy and diarrheic sheep feces, to evaluate its antimicrobial susceptibility profile, and to assess risk factors for Salmonella occurrence in Maya City, Eastern Ethiopia. Fresh fecal samples were randomly and purposively collected from apparently healthy and diarrheic sheep, respectively. Isolation and identification of non-typhoidal Salmonella was conducted according to ISO protocol (ISO-6579, 2007). Disk diffusion method was employed to evaluate the antimicrobial susceptibility of eight isolates. The collected data were analyzed using STATA software. Out of the total examined 213 fecal samples, 4.23% (9) were found positive for Salmonella, among which 5.56 % (8) and 1.45% (1) were isolated from healthy and diarrheic sheep. The prevalence of Salmonella was 2.4%, and 6.9% were positive for Salmonella in good and poor body condition, respectively. Prevalence was higher in older animals (8.5%) than young (1.8%) and adults (1.3%). Among herd sizes, 8.3% and 2.7% of sheep belonging to large and medium sized herds were positive for Salmonella, respectively while 0% in small herd sizes. Prevalence was higher in lowland area (8.33%) than in areas with mid-highland agro ecology (1.55%). However, breed, sex and clinical status of animal did not show significant differences (p>0.05). Multivariable logistic regression revealed a statistically significant difference among age group, altitudes, and body condition (p<0.05). Thus, being older age was more likely to harbor Salmonella in feces than their counterparts (AOR= 10; CI= 0.9- 90.9). For poor body condition the odds of shedding Salmonella in their feces were 5.1 fold compared to good body condition (AOR= 5.1; CI= 0.9- 24.4). Moreover, odds of fecal Salmonella shedding were 7.7 times higher (AOR=7.7; CI= 1.4- 41.1) in lowland sheep than mid-highland sheep. The highest level of resistance was observed for amoxicillin (100%), tetracycline (100%), and ampicillin (75%). Meanwhile, the highest susceptibility was to gentamycin (87%), SXT (75%), and ceftriaxone (75%). The detection of MDR isolates in food animals is an important alarm to consider an integrated mitigation options to prevent transmission to humans. Therefore, mixing of different age groups and different herds of animals together during housing should be avoided and further research on serotyping and molecular characterization of the isolate should be conducted in a wide geographical area.