Temperature Significantly Affects the Plaquing and Adsorption Efficiencies of Listeria Phages

Abstract

Listeria-infecting phages are currently being used to control and detect the important foodborne pathogen Listeria monocytogenes; however, the influence of environmental conditions on the interactions between L. monocytogenes and its phages has not been explored in depth. Here, we examined the infective potential of four Listeria phages (two each from the P70-like and P100-like phages of Listeria) against five strains of L. monocytogenes (representing serotypes 1/2a, 1/2b, 4a, and 4b) grown under a range of temperatures (7–37°C). We show that the plaquing efficiencies for all four phages were significantly affected by temperature. Interestingly, no plaques were observed for any of the four phages at 37°C. Adsorption assays performed with the P100-like phages, LP-048 and LP-125, showed that LP-048 had a severely reduced adsorption efficiency against susceptible strains at 37°C as compared to 30°C, suggesting that there is considerably less accessible rhamnose (LP-048’s putative phage receptor) on the host at 37°C than at 30°C. LP-125 adsorbed to host cells at 37°C, indicating that the inability for LP-125 to plaque at 37°C is not due to adsorption inhibition. LP-048 showed significantly higher adsorption efficiency against a mutant strain lacking N-acetylglucosamine in its wall teichoic acids (WTA) than the parental strain at both 30 and 37°C, suggesting that N-acetylglucosamine competes with rhamnose for glycosylation sites on the WTA. The data presented here clearly shows that L. monocytogenes can gain physiological refuge from phage infection, which should be carefully considered for both the design and implementation of phage-based control and detection applications.

Control ofSalmonellaEnteritidis on food contact surfaces with bacteriophage PVP-SE2

“…For instance, the replication of coliphage FRNA at lower than optimal cell growth temperature conditions is slower and can even cease because of the lower expression of F pili and adsorption inhibition (Knolle and Orskov 1967;Woody and Cliver 1995). Similar results have also been reported for phages of Listeria (Tokman et al 2016) and Pseudomonas fluorescens (Sillankorva et al 2004) where incubation at refrigeration temperatures resulted in an increase in the latent period, a reduction in phage burst size and overall lower killing efficacy.…”

Contrasting Controls on Microzooplankton Grazing and Viral Infection of Microbial Prey

“…Temperature can influences transport through energetic effects on Brownian motion and metabolic activity of motile organisms (Beveridge et al, 2010;Simoncelli et al, 2019). Temperature can also influence encounter through modifications in fluid viscosity, and is a factor influencing virus adsorption rates (Moldovan and Wu, 2007;Tokman et al, 2016). The effects of heterogeneous microenvironments and temperature on microbial predator-prey encounter and capture both require in-depth consideration, which we reserve for future investigation.…”

Nevertheless, She Resisted – Role of the Environment on Listeria monocytogenes Sensitivity to Nisin Treatment in a Laboratory Cheese Model

“…modification genes on the effect of environmental conditions over nisin efficacy, a non-polar, in-frame deletion mutation of mprF was constructed from the L. monocytogenes 10403S parent strain using the splicing by overlap extension (SOE) method as previously described (Horton et al, 1990;Wiedmann et al, 1998). Additionally, a dltAmprF mutant was constructed by deleting the mprF open reading frame (ORF) from a dltA mutant strain (Tokman et al, 2016) (Wiegand et al, 2008) after a 24 h incubation period at 37 • C, and it is reported in Table 1.…”