Bacteriophages reduce Yersinia enterocolitica contamination of food and kitchenware

Abstract

Yersinia enterocolitica, the primary cause of yersiniosis, is one of the most important foodborne pathogens globally and is associated with the consumption of raw contaminated pork. In the current study, four virulent bacteriophages (phages), one of Podoviridae (fHe-Yen3-01) and three of Myoviridae (fHe-Yen9-01, fHe-Yen9-02, and fHe-Yen9-03), capable of infecting Y. enterocolitica were isolated and characterized. fHe-Yen9-01 had the broadest host range (61.3% of strains, 65/106). It demonstrated a latent period of 35 min and a burst size of 33 plague-forming units/cell, and was found to have a genome of 167,773 bp with 34.79% GC content. To evaluate the effectiveness of phage fHe-Yen9-01 against Y. enterocolitica 0:9 strain Ruokola/71, we designed an experimental model of the food market environment. Phage treatment after bacterial inoculation of food samples, including raw pork (4 degrees C, 72 h), ready-to-eat pork (26 degrees C, 12 h), and milk (4 degrees C, 72 h), prevented bacterial growth throughout the experiments, with counts decreasing by 1-3 logs from the original levels of 2-4 x 10(3) CFU/g or ml. Similarly, when artificially contaminated kitchen utensils, such as wooden and plastic cutting boards and knives, and artificial hands, were treated with phages for 2 h, bacterial growth was effectively inhibited, with counts decreasing by 1-2 logs from the original levels of ca 10(4) CFU/cm(2) or ml. To the best of our knowledge, this is the first report of the successful application of phages for the control of Y. enterocolitica growth in food and on kitchen utensils.