Listeria monocytogenes is one of the most important bacterial foodborne pathogens. The ability to survive in diverse environmental conditions and the capacity to form biofilms are critical to guaranteeing food safety. No current data are available regarding the detection of this microorganism in fresh pork meat in the region. The aim of this study was to determine the presence of L. monocytogenes in fresh pork meat from meat retailers in La Plata, Buenos Aires, Argentina.

The present study is part of a food safety observational, transversal, and descriptive research project. From August to November 2024, a total of 138 pork meat samples were collected from 46 local meat retailers selected randomly in the city of La Plata. In each one of the stores, three samples were pooled to form a unique sample. Each pool of 25 g was cultured in 225 ml of Half Fraser broth for 24 h at 30 °C. After the pre-enrichment step, 0.1 ml of each culture was subcultured in 10 ml of secondary enrichment medium (Fraser) supplemented with 0.1 ml of ferric ammonium citrate for 48 h at 37 °C. Plating out and identification was performed with CHROMagar™ for Listeria according to the manufacturer’s instructions. Suspected L. monocytogenes were selected for biochemical identification according to ISO 11290-1, and those confirmed were subcultured and preserved at −20 °C. Of the 46 retailers sampled, 32.61 % resulted positive for Listeria monocytogenes. Although this is the first report of Listeria monocytogenes in fresh pork meat in the region, similar values were reported from beef butcher shops.

The isolation of this microorganism, its survival characteristics, and the context of meat retailers that sell ready-to-eat food products might indicate the presence of other foodborne pathogens implicated in cross-contamination and food safety, highlighting the importance of implementing good manufacturing practices.