The rise of pathogens: predation as a factor driving the evolution of human pathogens in the environment.
Bacteria in the environment must survive predation from bacteriophage, heterotrophic protists, and predatory bacteria. This selective pressure has resulted in the evolution of a variety of defense mechanisms, which can also function as virulence factors. Here we discuss the potential dual function of some of the mechanisms, which protect against heterotrophic protists, and how predation pressure leads to the evolution of pathogenicity. This is in accordance with the coincidental evolution hypothesis, which suggests that virulence factors arose as a response to other selective pressures, for example, predation rather than for virulence per se. In this review we discuss some of those environmental factors that may be associated with the rise of pathogens in the marine environment. In particular, we will discuss the role of heterotrophic protists in the evolution of virulence factors in marine bacteria. Finally, we will discuss the implications for expansion of current pathogens and emergence of new pathogens.
Centre for Marine Bio-Innovation, School of Biotechnology and Biomolecular Science, University of New South Wales, Sydney, New South Wales, 2052, Australia.
Martina
M
Erken
Carla
C
Lutz
Diane
D
McDougald
D000818:Animals; D001419:Bacteria / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity; D001424:Bacterial Infections / Q000382:microbiology*; D005075:Biological Evolution; D017753:Ecosystem; D006801:Humans; D012623:Seawater / Q000382:microbiology*; D037521:Virulence Factors / Q000235:genetics* / Q000378:metabolism
D037521:Virulence Factors