When I originally got interested in microbes, it was mostly for somewhat obscure academic questions about mobile genetic elements: how does evolution solve conflicts to create cohesive individuals instead of loose associations of genes? The abundance of plasmids and phage, and the fact that they sometimes carry genes for antibiotic resistance or pathogen virulence, seemed like a situation where that integration was not fully complete, which made them a good system to study. The fact that microbes and their mobile elements had significant effects on human health was a nice bonus, but not my main motivation. Mostly, I was happy that a lot of the genetic details had already been worked out. I liked the infectious disease aspect, but again mainly for academic reasons about conflict evolution, not because of its practical importance for humans.
Now, I find myself finding the applied aspects more compelling. They’re still not the primary thing, but if you have a choice of systems to study for academic reasons, why not study one that’s also relevant to human welfare? I’ve spent the last several years studying microbial cooperation in Myxococcus bacteria and Dictyostelium amoebae. These organisms are pretty cool biologically, but they really don’t have much to do with humans. Other examples of microbial cooperation are maybe more plain but also more relevant, like the Pseudomonas bacteria that kill people with cystic fibrosis.
I also recently realized the potential practical implications of my old grad school work on plasmids. In those experiments, I observed a rapid, repeatable loss of antibiotic resistance and a suppressed proliferation of bacteria — both of which are desirable clinical outcomes. I’d never really thought about those results from an applied standpoint. Why did my plasmids evolve to get rid of resistance genes while in other people’s experiments they stuck around even when there were no antibiotics? Is it possible to influence natural plasmid evolution to follow the path I saw? It’s definitely worth following up on.