Prevalence of subclinical mastitis in sheep, etiological agents, and antimicrobial susceptibility in Northern Cyprus

In Northern Cyprus, around 51% of halloumi cheese is produced from sheep milk, and therefore the livelihood of the farmers mostly depends on the sheep milk production. However mastitis, an inflammation of the udder, significantly affects this production. Due to a lack of sufficient data concerning the prevalence, etiology, and antimicrobial resistance of sheep mastitis, there remains no effective method to control the disease. This study aims to estimate the prevalence of subclinical mastitis (SCM) and identify bacterial etiological agents and the antimicrobial susceptibility profiles of bacterial isolates in sheep in Northern Cyprus. A total of 227 milk samples taken from sheep were analysed using somatic cell count (SCC), bacteriological isolation-identification, and antimicrobial susceptibility procedures. Pathogens were isolated in 62 (27.3%) sheep milk samples. Somatic cell counts of more than 500000 cells/ml were found in 56 (24.6%). S. aureus (12.8%) was the most common isolate from the milk samples, followed by NAS (non-Aureus staphylococci) species (11.9%), Escherichia coli (0.9%), Streptococci (0.4%), Bacillus spp. (0.9%) and Staph spp. (0.4%). While a high resistance to sulphamethaxazole/trimetoprim (81.5%) was found, no resistance to gentamicin (10.6%) was found. The study findings indicate that subclinical mastitis is a serious problem in Cyprus. Therefore, continuous observation of subclinical mastitis and application of antibiogram tests to combat mastitis and antibiotic resistance and reduce economic losses are needed.