Phage adsorption and lytic propagation in Lactobacillus plantarum: Could host cell starvation affect them?

Abstract

BackgroundBacteriophages constitute a great threat to the activity of lactic acid bacteria used in industrial processes. Several factors can influence the infection cycle of bacteriophages. That is the case of the physiological state of host cells, which could produce inhibition or delay of the phage infection process. In the present work, the influence of Lactobacillus plantarum host cell starvation on phage B1 adsorption and propagation was investigated.ResultFirst, cell growth kinetics of L. plantarum ATCC 8014 were determined in MRS, limiting carbon (S-N), limiting nitrogen (S-C) and limiting carbon/nitrogen (S) broth. L. plantarum ATCC 8014 strain showed reduced growth rate under starvation conditions in comparison to the one obtained in MRS broth. Adsorption efficiencies of > 99 % were observed on the starved L. plantarum ATCC 8014 cells. Finally, the influence of cell starvation conditions in phage propagation was investigated through one-step growth curves. In this regard, production of phage progeny was studied when phage infection began before or after cell starvation. When bacterial cells were starved after phage infection, phage B1 was able to propagate in L. plantarum ATCC 8014 strain in a medium devoid of carbon source (S-N) but not when nitrogen (S-C broth) or nitrogen/carbon (S broth) sources were removed. However, addition of nitrogen and carbon/nitrogen compounds to starved infected cells caused the restoration of phage production. When bacterial cells were starved before phage infection, phage B1 propagated in either nitrogen or nitrogen/carbon starved cells only when the favorable conditions of culture (MRS) were used as a propagation medium. Regarding carbon starved cells, phage propagation in either MRS or S-N broth was evidenced.ConclusionsThese results demonstrated that phage B1 could propagate in host cells even in unfavorable culture conditions, becoming a hazardous source of phages that could disseminate to industrial environments.

Slow growing bacteria survive bacteriophage in isolation

“…Changes in nutrient availability affect bacterial growth and increasing evidence suggests that the rate of phage population growth and burst size increase with increasing bacterial growth rate [ 14 – 16 ] and are life-cycle dependent [ 17 ], whereas the eclipse and latent periods reduce with increasing bacterial growth rate [ 14 – 16 ]. However, some phage are also capable of infecting slowly growing stationary phase or starved bacterial populations [ 18 – 21 ]. Moreover, lysis of the host bacterium can be delayed by the infecting phage for several hours in the event of adsorption of one or more secondary phage which leads to superinfection and lysis inhibition [ 22 – 24 ].…”

Clinical Pharmacology of Bacteriophage Therapy: A Focus on Multidrug-Resistant Pseudomonas aeruginosa Infections

“…Even though phage binding to the surface of the bacterium is considered as an energy-independent process, the consequential steps in the life of phage are energy-dependent. Previous researchers showed that although phage PL-1 was adsorbed on the surface of starved host cells, the next step of DNA injection was not achieved in the absence of an active cell metabolism (i.e., a reduction in intracellular ATP content) [ 165 ]. Typically, various components present in the phage–bacterium environment can impact phage adsorption, as phage propagation is strongly dependent on the physiological state of the host.…”

“…This is due to the activation/de-activation of host receptors at certain temperatures [ 166 ]. Starvation conditions, such as a lack of nitrogen in a broth, have been found to inhibit phage adsorption and propagation in Lactobacillus Plantarum ATCC 8014 [ 165 ]. Another report postulated that a common site on the cell envelope (a protein involved in iron transport) of Salmonella typhimurium binds to both ferrichrome and phage ES18 [ 168 ].…”

Innovative Feasibility Study for the Reclamation of the Cascajo Wetlands in Peru Utilizing Sustainable Technologies

“…It was kept routinely in vials with full form (MRS) agar at 2-8 • C for 24 h, and then at 4 • C in 15% glycerol (vol/vol) [24]. Single colonies were cultured in plates with MRS agar at 30 • C for 48 h and later sub-cultured in MRS broth (Casein peptone 10g/L; beef extract 8 g/L; yeast extract 4 g/L; D(+) glucose 20 g/L; hydrogen potassium phosphate (KH 2 PO 4 ) 2 g/L; Tween- 80 [53]. The cultures in the MRS broth develop characteristic white sediment, making it easier for their qualitative identification.…”