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Based on previous studies, empirical distribution of the bacterial burst size varies even in a population of isogenic bacteria. Since bacteriophage progenies increase linearly with time, it is the lysis time variation that results in the bacterial burst size variations.

Here, the burst size variation is computationally modeled by considering the lysis time decisions as a game. Each player in the game is a bacteriophage that has initially infected and lysed its host bacterium. Also, the payoff of each burst size strategy is the average number of bacteria that are solely infected by the bacteriophage progenies after lysis. For calculating the payoffs, a new version of ball and bin model with time dependent occupation probabilities (TDOP) is proposed.

We show that Nash equilibrium occurs for a range of mixed burst size strategies that are chosen and played by bacteriophages, stochastically. Moreover, it is concluded that the burst size variations arise from choosing mixed lysis strategies by each player. By choosing the lysis time and also the burst size stochastically, the released bacteriophage progenies infect a portion of host bacteria in environment and avoid extinction. The probability distribution of the mixed burst size strategies is also identified.

In this highlight an overview of the advances performed by the Aveiro group on the design and synthesis of tetrapyrrolic photosensitizers with potential photodynamic antimicrobial activity is presented.

Photodynamic therapy is a platform technology which uses a combination of a photosensitizer, light and molecular oxygen to achieve selective destruction of a biological target. This methodology is already in use for the inactivation of microorganisms but its application in wastewater disinfection is incipient. In this work we tested the effect of three solid matrixes with immobilized porphyrins in the photoinactivation of a sewage bacteriophage. The phage inactivation to the limits of detection (reductions of about 7 log) with one of the tested materials, means that this insoluble material can be applied in wastewater disinfection with the same efficacy of the non-immobilized photosensitizer. The complete eradication of viruses with low light intensity means that this technology can be applied to wastewater disinfection under natural irradiation conditions during all year, including the cloudy days of winter. In addition, this is an inexpensive and easily applicable methodology.

The aim of this study was to produce biofilms of Salmonella Enteritidis in stainless steel coupons and evaluate its reduction by the use of a pool of lytic bacteriophages. It was observed an increase in the number of cells in the biofilm according to the time of cultivation, in which the count of Salmonella spp. was 6.1 log UFC^.cm^-2 to 4 days, 6.9 log UFC^.cm^-2 with 8 days and 7.7 log UFC^.cm^-2 with 12 days. The largest reductions by the action of bacteriophages were observed in treatments with 10⁷ PFU^.mL^-1 of bacteriophages, 35 min of contact with biofilm at 8 days of age. Bacteriophages that were used were able to reduce the Salmonella Enteritidis biofilm in coupons of stainless steel of different ages, and are an alternative to control this pathogen in the food industry.