Survie du Salmonella paratyphi B et du Pseudomonas aeruginosa dans l'eau de mer après incubation ou lavage en présence d'osmolytes

The authors have compared the survival in seawater of Salmonella paratyphi B and Pseudomonas aeruginosa cells grown at low or high osmolarity, in the presence of organic osmolytes: glycine betaine, choline, proline, and glutamate. The four substrates enhanced the survival potential of S. paratyphi B while only glycine betaine protected P. aeruginosa. In addition only S. paratyphi B cells were more resistant after a preliminary growth at high osmolarity. Both bacteria were sensitive to osmotic down-shock, sensitization of S. paratyphi B being inversely proportional (p ≥ 0.01) to the osmolarity of the medium used to wash cells. The transit in wastewater, at low osmolarity, can therefore modify the behavior of these pathogens in the marine environment. Key words: Salmonella paratyphi B, Pseudomonas aeruginosa, survival, seawater, osmotic shock.