Emergence and Evolution of Bacterial Pathogens
“The Greeks have given us one of the most beautiful words of our language: Enthusiasm, a God within. The grandeur of the acts of women and men are measured by the inspiration from which they spring” Louis Pasteur
Bacteria have colonized the Earth for billions of years and are ubiquitously distributed throughout the globe: from the inhospitable glaciers of Antarctica to scorching deep-sea vents in the Galapagos Rift. Their propensity to exchange genetic material and responsiveness to environmental fluctuations make prokaryotes a captivating group in which to study evolution and niche colonization.
Since the dawn of humanity, bacteria have devised numerous ways to effectively colonize us. Among other strategies, such as symbiosis or commensalism, some microorganisms have emerged as human pathogens. These changes came about through a variety of mechanisms including the acquisition of novel traits encoded in genetic clusters such as pathogenicity islands or lysogenic phages, incremental change, or the repurposing of old traits that formerly had a function in their natural environment.