Detection of Salmonella from raw cow milk and beef and its antibiotic susceptibility profile in selected districts of the Sidama Regional State, Ethiopia.

BACKGROUND

is one of the most common causes of foodborne diseases and is frequently reported to exacerbate the increase in multidrug resistance worldwide. Poor hygienic practices along the food chain and the cultural habits of consuming raw animal products contribute to the spread of infection and increased antibiotic resistance, especially in developing nations like Ethiopia.

METHODS

A cross-sectional study was conducted from December 2022 to June 2023. The study aimed to detect and determine the antibiotic susceptibility of from cow milk and beef in the Hawassa, Yirgalem and Wondo Genet districts of the Sidama Regional State. A total of 216 samples (121 milk, 31 yogurt and 64 beef samples) were collected and analyzed using standard bacteriological procedures for the isolation and identification of . Positive isolates were further confirmed by polymerase chain reaction (PCR). was tested for antibiotic susceptibility using the Kirby-Bauer disk diffusion method.

RESULTS

was isolated from 6.5% to 4.17% of the total samples by culture and PCR-based methods, respectively. Prevalence at the sampling sites was 5.38% in Hawassa, 3.23% in Yirgalem, and 2.38% in Wondo Genet. There was no significant variation in prevalence among the districts ( = 0.18) or between milk (3.9%) and beef (4.7%) samples ( = 0.73). Likewise, there was no significant variation ( = 0.66) in isolation rate among retailers (4.84%), households (5.56%) and farms (1.85%), or between yogurt (6.45%) and raw milk (3.31%) ( = 0.10). Antibiotic susceptibility testing indicated that all isolates were 100% resistant to ampicillin, nalidixic acid, clindamycin and cephalothin, while showing varying sensitivity to ceftriaxone (88.9%), chloramphenicol (55.6%) and gentamycin (66.7%). All isolates exhibited multidrug resistance (MDR).

CONCLUSION

This study reveals that is prevalent in cow’s milk and beef produced and consumed in the study area, and has developed MDR, which poses a public health threat. Therefore, it is essential for dairy farmers, and milk and beef retailers to take necessary measures to minimize contamination in their products. Furthermore, dedicated engagement from district level animal health departments in educating dairy farmers about proper use of antibiotics at farm level would play a pivotal role in mitigating the increasing antibiotic resistance in spp.