Survival of genetically-marked Aeromonas hydrophila in water

Survival of a genetically‐marked Aeromonas hydrophila was monitored in water microcosms. There was no apparent loss of a marker plasmid which encoded the xylE reporter gene during prolonged incubation in lake water. Survival was best in sterile lake water but in sea water, cells died rapidly during the first 9 d, recovered up to day 12 and thereafter numbers fell up to 28 d accompanied by loss of the plasmid in a proportion of the cells.