Insights from genomics into bacterial pathogen populations

Abstract

Bacteria are the most abundant group of organisms, and a major source of human disease and mortality. Bacterial cells account for most of the earth's biomass [1], and the 100 trillion microbial residents of the human body outnumber human cells 10 to 1 [2]. Bacteria that cause pneumonia, diarrhea, and tuberculosis are leading causes of death worldwide [3], [4]. In countries with a low overall burden of infectious disease such as the United States, bacteria are nevertheless responsible for more than 60% of the deaths attributable to communicable disease, with hospital-associated infections, HIV-associated infections, and tuberculosis most prominent (Table 1).