AUTHOR=Stone Edel , Lhomet Antoine , Neve Horst , Grant Irene R. , Campbell Katrina , McAuliffe Olivia 

TITLE=Isolation and Characterization of Listeria monocytogenes Phage vB_LmoH_P61, a Phage With Biocontrol Potential on Different Food Matrices

JOURNAL=Frontiers in Sustainable Food Systems

VOLUME=Volume 4 - 2020

YEAR=2020

URL=https://www.frontiersin.org/journals/sustainable-food-systems/articles/10.3389/fsufs.2020.521645

DOI=10.3389/fsufs.2020.521645

ISSN=2571-581X

ABSTRACT=The high mortality rate associated with Listeria monocytogenes as well as its ability to adapt to the harsh conditions employed in food processing have ensured that this pathogen has become a significant concern in the ready-to-eat food industry. Lytic bacteriophages are viruses that hijack their bacterial host’s metabolic mechanisms as a means to grow and replicate, subsequently leading to host cell death due to lysis. With emerging concerns related to the increasing numbers of antibiotic-resistant pathogens, bacteriophages may act as a suitable biocontrol alternative. This study reports the biological and genomic characterisation of the broad host range Listeria monocytogenes phage vB_LmoM_P61 and its potential application for the reduction of Listeria monocytogenes in artificially contaminated foods. Phage vB_LmoM_P61 is a virulent bacteriophage belonging to the family Myoviridae and has a genome size of 136,481 bp. The lytic spectrum of vB_LmoM_P61 was investigated and the genomic basis for its observed serotype specificity (1/2a, 1/2b, 1/2c, 4b, 4e and 6a) investigated using comparative genomics. Treatment of artificially contaminated milk with vB_LmoM_P61 resulted in a significant reduction in Listeria monocytogenes numbers when stored at 8 °C and 12 °C for the duration of the shelf life. The results also show that vB_LmoM_P61 reduced the growth of L. monocytogenes when baby spinach was artificially contaminated and stored at 8 °C and 12 °C. Preliminary studies were carried out on other solid food matrices such as fresh pesto and hummus, however vB_LmoM_P61 was inactivated in these matrices and significantly reduced in concentration. The research findings indicate that biocontrol of Listeria monocytogenes with vB_LmoM_P61 may offer a safe and environmentally friendly approach for the reduction of Listeria monocytogenes numbers in some ready-to-eat foods.