Occurrence and genetic relatedness of Listeria spp. in two brands of locally processed ready-to-eat meats in Trinidad

Contamination of locally produced, ready-to-eat meats by Listeria spp. has been previously reported at one processing plant in Trinidad. However, the status of this pathogen in locally produced products sold at retail outlets is unknown. This study was conducted to establish whether there is a risk to consumers of locally processed meats caused by the presence of Listeria spp., and whether a link exists between the presence of the pathogen in retail products and the manufacturing plant of one brand (B). Four hundred and eighty ready-to-eat meat products of two popular local brands (A and B) were collected from retail outlets and analysed for the presence of Listeria spp. together with food samples and surfaces from one manufacturing plant (B). Eighty-eight of the retail products (18·3%) were contaminated with Listeria spp., of which, 52·3% were L. innocua, 44·3% were L. monocytogenes and 3·4% belonged to the L. seeligeri–L. welshimeri–L. ivanovii (Siwi) group. L. innocua was found in 15 in-process food samples and on three surfaces of equipment at plant B. Four in-process food samples were also contaminated with Siwi isolates. Repetitive extragenic palindromic PCR DNA fingerprinting showed a possible association between strains of different Listeria spp. and brand as well as with manufacturing plant B.