14 Dec 2020
Setting it Straight: Pathogenesis, infection and the ecosystem within
Setting it Straight - Issue #37
Last week I suggested that each and every one of us is a complex of interlinked ecosystems, with the inhabitants of our ‘land and sea scapes’ being the viruses, bacteria and other organisms that live in or on us. Considering the amount of DNA that we lug around each day, most of it is in the 100 trillion (1014) bacteria of our gut microbiome (#2). Thinking of the planetary ecosystem, human numbers are getting up to around eight billion (1010). The most numerous vertebrates are probably fish (1013+), with more than 1010 domestic chickens, and so forth. As with the vertebrate species that inhabit the earth, some ‘friendly’ (commensal) microbes serve our needs by providing nutrients (vitamins K, B12, riboflavin and thiamine) or are just passengers passing through, while a small minority are predators (pathogens) that invade and potentially do us harm. Across the planet while we might worry more about being attacked by sharks, which clean up the oceans and, like SARS-CoV-2, occasionally kill or maim fit young surfers and swimmers, human beings are the top predators.