Four antimicrobial feeding treatments(ampicillin, kanamycin, metronidazole, and tetracycline) were used to experimentally induce dysbiosis in the termite gut and quantify changes in community ecology and digestion.
To first determine if these antimicrobials fould reduce bacterial populations, gut bacteria were isolated and quantified using traditional culturing techniques.
The two broad- spectrum antimicrobials, kanamycin and tetracycline, significantly reduced the culturable community of bacteria isolated from the termite gut(Fig. 1 Ampicillin, which targets gram-positive bacte- ria, and metronidazole, an antiprotozoan, did not significantly reduce the culturable bacterial community. Antimicrobial treatments also resulted in non-significant changes to the culturable, anaerobic community(Fig. S1) In addition to reductions in bacterial load, kanamycin, metronidazole, and tetracycline treatments also impacted protist abundance significantly(Fig. 1B) overall. all microbial treatments significantly reduced the symbiont load, both bacteria and protists, in a seven-day feeding period(Fig. 1