Anany_Bacteriophages as Biosanitizers: Using Lytic Phage to Eradicate L mono Biofilm

Citation

Cucic, Stevan, Janet Lin, Cezar Khursigara, and Hany Anany. "Bacteriophages as Biosanitizers: Using Lytic Phage to Control and Eradicate Listeria monocytogenes Biofilm." In program book of IAFP 2019 Annual Meeting, Louisville, USA.

Plain language summary

Introduction: Listeria monocytogenes is a foodborne pathogenic bacterium that causes invasive listeriosis in people with compromised immunity. Apart from its ability to persist at refrigeration temperature, over a wide range of pH, and at high osmolarity, the propensity of L. monocytogenes to produce biofilms and survive in mixed-species biofilms contributes to its persistence in food processing environments. Lytic Listeria phages represent a strategy to control sessile L. monocytogenes.
Purpose: The purpose of this study is to investigate the biosantiation potential of lytic phages against sessile L. monocytogenes .
Methods: Strains of different L. monocytogenes serotypes (1/2a, 1/2b and 4b) were tested for their ability to form biofilms on polystyrene using a 96-well plate static culture crystal violet biofilm assay. The strains were inoculated at similar levels in TSB supplemented with 1% glucose and 2% NaCl and incubated for 24 hours at 25°C. For isolation of biofilm-degrading Listeria phages, environmental samples were collected from poultry and dairy processing facilities and L. monocytogenes ATCC19111 (serotype 1/2a) was used as the enrichment strain. Clear plaques with halos were selected for phage purification and characterization . Moreover, the ability of the commercially available Listex P100 phage to degrade a 24-hour L. monocytogenes biofilm was investigated at 25°C in static culture.
Results: L. monocytogenes ATCC 19111 (serotype 1/2a) produced significantly more adherent biomass than the other strains tested. Moreover, our results showed that concentrations of P100 of 107 and 109 PFU/ml were significantly effective in eradicating biomass produced by adherent L. monoycogenes. Four phage isolates producing clear plaques with haloes were obtained from a poultry run-off sample and phages were detected in samples from a dairy facility.
Significance: These results suggest that phages may be effective to control mono-species biofilms of L. monocytogenes and provide a baseline for comparison with other Listeria phages isolated in this study.

Abstract

Introduction: Listeria monocytogenes is a foodborne pathogenic bacterium that causes invasive listeriosis in people with compromised immunity. Apart from its ability to persist at refrigeration temperature, over a wide range of pH, and at high osmolarity, the propensity of L. monocytogenes to produce biofilms and survive in mixed-species biofilms contributes to its persistence in food processing environments. Lytic Listeria phages represent a strategy to control sessile L. monocytogenes.
Purpose: The purpose of this study is to investigate the biosantiation potential of lytic phages against sessile L. monocytogenes .
Methods: Strains of different L. monocytogenes serotypes (1/2a, 1/2b and 4b) were tested for their ability to form biofilms on polystyrene using a 96-well plate static culture crystal violet biofilm assay. The strains were inoculated at similar levels in TSB supplemented with 1% glucose and 2% NaCl and incubated for 24 hours at 25°C. For isolation of biofilm-degrading Listeria phages, environmental samples were collected from poultry and dairy processing facilities and L. monocytogenes ATCC19111 (serotype 1/2a) was used as the enrichment strain. Clear plaques with halos were selected for phage purification and characterization . Moreover, the ability of the commercially available Listex P100 phage to degrade a 24-hour L. monocytogenes biofilm was investigated at 25°C in static culture.
Results: L. monocytogenes ATCC 19111 (serotype 1/2a) produced significantly more adherent biomass than the other strains tested. Moreover, our results showed that concentrations of P100 of 107 and 109 PFU/ml were significantly effective in eradicating biomass produced by adherent L. monoycogenes. Four phage isolates producing clear plaques with haloes were obtained from a poultry run-off sample and phages were detected in samples from a dairy facility.
Significance: These results suggest that phages may be effective to control mono-species biofilms of L. monocytogenes and provide a baseline for comparison with other Listeria phages isolated in this study.

Publication date

2019-07-21

Author profiles