Antimicrobial susceptibility of coagulase-negative Staphylococci isolated from mastitic cattle in Brazil [Susceptibilidade antimicrobiana de cepas de Staphylococci coagulase-negativa isoladas de leite de bovinos com mastite no Brasil]

Mastitis is the most common and costly disease of dairy cows (Hortet and Seegers, 1998; Zafalon et al., 2007); this is also the single most common reason for antimicrobial use in dairy herds, since antimicrobial therapy is the major primary tool for mastitis control in lactating and dry cows. Recently, coagulase-negative Staphylococci (CNS) are increasing in importance as cause of bovine intramammary infection (IMI) all over the world. They have been isolated from milk samples collected from cows with clinical and subclinical mastitis in several countries (Aarestrup et al., 1995; Gentilini et al., 2002; Amaral et al., 2003).