In the 1970s he discovered plasmids as the mechanism of transfer of genetic material conferring antibiotic resistance to bacteria, and later that finding extended into understanding horizontal gene transfer of genetic material associated with causing disease in the host. This work laid the foundation for much of the research that we do in the Pooper Scooper lab, in the areas of the epidemiology of antibiotic resistance and microbial pathogenesis. Some of his first work on virulence factors focused on mobile genetic elements that encode a toxin from a diarrhea-causing E. coli. His Nature obituary states that "The question that framed Falkow’s career was: what is a pathogen? Specifically, what makes some microbes disease agents, while others are innocuous or even beneficial?" This is one of the fundamental questions that we are asking, using an epidemiological perspective, in our new cohort study in Ecuador.
He also sets an example that I can only hope to emulate on simultaneously thinking big while also going deep by doing robust research. His paper with Marty Blaser on the disappearing microbiota was one of the first papers I read on the microbiome, and very influential to my thought in this area (although we are focused on converse question... what are the benefits of a diverse microbiota).
I particularly admire his track record of mentoring. He trained hundreds of scientists, many of whom have gone on to impressive scientific careers. I hope that I can similarly share my passions with the students who pass through my research group.
The microbes will no doubt recycle his biomass, and the generations of scientists who follow him will recycle and build upon the ideas that he put forth into the world.