Analysis of bulk goats' milk and milk-filters from Valtellina and Valchiavenna (Lombardy Prealps) for the presence of Listeria species

Ninety-six samples of bulk untreated goats' milk and 96 milk-filter samples, obtained monthly from eight farms in Valtellina and Valchiavenna, province of Sondrio, Lombardy Prealps, Italy, from October 2002 to October 2003, were subjected to exhaustive micro-biological analyses for the presence of Listeria spp. Two (2.1%) milk samples and six (6.3%) filter samples were positive for non-pathogenic Listeria species: L. innocua or L. ivanovii in milk; L. innocua, L. ivanovii or L. grayi in milk-filters. No strains pathogenic for humans (in particular L. monocytogenes) were present. This is a reassuring finding particularly as some of the farms are using their untreated milk to produce cheeses on the farm.