Isolation, Identification and Antimicrobial Resistance Profile of Staphylococcus aureus and Occurrence of Methicillin Resistant S. aureus Isolated from Mastitic Lactating Cows in and around Assosa Town, Benishangul Gumuz Region, Ethiopia

Ethiopia has the largest cattle population in Africa with an estimated population of 52.13 million [1] and contributes 40 % to the annual agricultural output, and 15% total gross domestic product. Cattle produce a total of 1.5 million tonnes of milk and 0.331 million tonnes of meat annually. Cows represent the biggest portion of cattle population of the country, around 42% of the total cattle heads are milking cows [1]. However, milk production often does not satisfy the country’s requirements due to a multitude of factors. Mastitis is among the various factors contributing to reduced milk production [2]. Bovine mastitis is an infectious inflammation or irritation of the mammary glands that interferes with the normal flow and quality of milk. Among mastitis causing pathogens, the S.aureus bacterium is a major pathogen of intramammary infections in dairy cattle It is an important opportunistic pathogen both in humans and in dairy cattle [3,4] S. aureus is present in a variety of locations in the dairy farms, in many occasions it was isolated from swabs taken from the cows head, skin swabs, legs and nasal mucosa and also on the milkers’ hands. However an infected udder quarter remains the main reservoir of the bacteria, which transmitted mostly during the milking time [5].