Co-colonization of Euprymna scolopes by coisolated Vibrio fischeri strains

The symbiosis between the Hawaiian bobtail squid and the bacterium Vibrio fischeri can be used as a model to study growth inhibition of coisolated symbionts. One interaction that results in inhibition is the activity of bacterial encoded type six secretion systems (T6SSs). Using fluorescence spotting assays and squid colonization assays, the growth inhibition phenotypes and colonization abilities of strains were determined. Coisolated strains encoding T6SSs exhibited growth inhibition in vitro, but colonized the same animal.