Determination of Risk Factors Associated With Mastitis and Antimicrobial Susceptibility Profiles of Bacteria Isolated From Mastitic Milk in Dairy Camels in Benaadir Region in Somalia

Abstract

Camels can withstand arid and semi-arid harsh climatic conditions where crop production and other livestock species are limited. There are two camel species- Camelus bacterianus (Bactrian) and Camelus dromedarious (Arabian) - which have two and one humps, respectively. These species can produce milk even under extreme conditions. However, mastitis, an inflammation of the udders, has been globally reported among the key zoonotic diseases that threaten the dairy industry. This study was designed to establish the prevalence of mastitis in dromedary in Benaadir Region, Somalia, factors associated with its occurrence and the antimicrobial susceptibility profiles of mastitic milk isolates. The study was cross-sectional; including usage of semi-structured questionnaires and bacterial isolation from milk samples. The questionnaires were administered to 96 camel keepers in Huriwa, Dharkenley, and Yaqshid regions in Benaadir district- Somalia, while a total of 290 she-camels had their milk sampled and processed for bacterial isolation. The milk samples were collected directly from cleaned udders early in the morning. After discarding the first four streams of milk, the California Mastitis Test (CMT) was carried out, and then approximately 10 ml of milk from each half was collected into labelled sterile tubes and transported in frozen conditions to the Department of veterinary pathology, microbiology and parasitology (VPMP), University of Nairobi, for bacterial isolation and identification. Using CMT, the overall prevalence of subclinical mastitis was 29.0% (83/286). The prevalences of subclinical mastitis were 28.1% (27/96), 29.5% (28/96) and 30.2% (29/96) in Huriwa, Dharkenly and Yaqshid districts, respectively. From the milk samples, the highest bacterial isolates (50.0%) were from Huriwa district, whereas Dharkenly and Yaqshid districts had 26.3%, and 27.5%, respectively. The bacterial isolates included Staphylococcus aureus, Streptococcus spp., and Escherichia coli. Notably, these bacterial isolates were not only resistant to most of the tested antibiotics but also had multi-drug-resistant strains. The three were resistant to Penicillin at 34.62%, 100% and 100%, respectively. Staphylococcus aureus s, which exhibited resistance to most of the tested antibiotics, showed resistance to Ampicillin, Erythromycin and Streptomycin at 42.31%, 7.69% and 42.31%, respectively. Based on the odds ratio, the questionnaire data showed that respondents practising semi-intensive farming were 27 times more likely to experience mastitis among camels [ Exp (B)= 27.28; 95% CI: 1.360, 547.08; p=0.031]. Among the farming systems, the majority 65% of respondents reported mastitis in camels and practised semi-intensive farming systems whereas both intensive and extensive farming systems had mastitis at less than 20% each. The study has shown that clinical and sub-clinical camel mastitis cases are prevalent in Benaadir and that the most common causative agents are Streptococcus spp, Staphylococcus spp, and Escherichia coli spp. Since a semi-intensive farming system was established as a factor associated with the occurrence of mastitis in the region, efforts need to be made to educate the camel keepers not only on hygiene and good milking practices but also on good farming practices, to minimize the potential for getting mastitis among camels. The data is expected to help the authorities in the Benadir region in coming-up with respective control measures for the region.