Letter to the editor: Do coagulase-negative staphylococci have no effect on the milk composition of infected mammary gland? A comment on Tomazi et al. (2015).

Strains of coagulase negative staphylococci (CNS) are the main bacteria species causing infection of the mammary gland in dairy cows, goats and sheep (Silanikove et al., 2014a). Recently, Tomazi et al. (2015) published a paper showing that apart from a modest increase in somatic cell count, infection with CNS had no effect on milk yield and milk composition of the infected glands in comparison to uninfected glands. Whereas, we cannot argue with the data itself, we think that simple adoption of the implication of this study might be associated with spreading of erroneous concept regarding the importance of CNS infection in dairy cows husbandry.