Diversity of gram-positive catalase-negative cocci in sheep bulk tank milk by comparative 16S rDNA sequence analysis

The species diversity of 192 isolates of a collection of Gram-positive catalase-negative cocci (GPCNC) from sheep bulk tank milk was investigated using 16S rDNA sequencing. A molecular approach enabled the identification of 23 species of GPCNC of sanitary and technological importance within the Enterococcus, Streptococcus, Lactococcus, Aerococcus and Trichococcus genera. This is relevant since ovine dairy products might be a source of commensal and potentially pathogenic or drug resistant GPCNC. Control strategies are needed in the food chain to optimise food safety and product development.