Characterisation of Listeria monocytogenes Isolates from Poultry by Serotyping and Phage Typing

With the aim of improving the knowledge of Listeria monocytogenestypes distributed in poultry, isolates collected from a hundred eviscerated and refrigerated chicken carcasses from four different slaughterhouse plants in northwest Spain were characterised by serotyping and phage typing. Forty-two phage patterns were observed. Eight phage patterns (43, 43/387, 43/387/4477/1652 and 43/19/387/575 for strains of serogroup 1/2 and 107, 108/107/47, 2389 and 2389/3274 for strains of serogroup 4) were the most common. Thus, thirty strains (56.60% of phage typeable strains) showed the above-mentioned or indistinguishable (1 major phage reaction differences for serogroup 1/2 strains or 2 major differences for serogroup 4) patterns. A wide distribution of some L. monocytogenesphage types was observed because different chicken carcasses (including carcasses from different slaughterhouses) were contaminated with the same or indistinguishable L. monocytogenesphage types. Besides, more than one type (serogroup or phage ...