Many viruses cause both lytic infections, where they release viral particles, and dormant infections, where they await future opportunities to reactivate. The benefits of each transmission mode depend on the density of susceptible hosts in the environment. Some viruses infecting bacteria use molecular signaling to respond plastically to changes in host availability.
View Article and Find Full Text PDFThe growth and virulence of bacteria depends upon a number of factors that are secreted into the environment. These factors can diffuse away from the producing cells, to be either lost or used by cells that do not produce them (cheats). Mechanisms that act to reduce the loss of secreted factors through diffusion are expected to be favoured.
View Article and Find Full Text PDFBacteria perform cooperative behaviors that are exploitable by noncooperative cheats, and cheats frequently arise and coexist with cooperators in laboratory microcosms. However, evidence of competitive dynamics between cooperators and cheats in nature remains limited. Using the production of pyoverdine, an iron-scavenging molecule, and natural soil populations of Pseudomonas fluorescens, we found that (1) nonproducers are present in the population; (2) they co-occur (<1cm ) with pyoverdine producers; (3) they retain functional pyoverdine receptors; and (4) they can use the pyoverdine of on average 52% of producers.
View Article and Find Full Text PDFBacteriocins are toxins produced by bacteria to kill competitors of the same species. Theory and laboratory experiments suggest that bacteriocin production and immunity play a key role in the competitive dynamics of bacterial strains. The extent to which this is the case in natural populations,especially human pathogens, remains to be tested.
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