title: Persistence of adhesive properties in Vibrio cholerae after long-term exposure to sea water.
abstract: The effect of exposure to artificial sea water (ASW) on the ability of classical Vibrio cholerae O1 cells to interact with chitin-containing substrates and human intestinal cells was studied. Incubation of vibrios in ASW at 5 degrees C and 18 degrees C resulted in two kinds of cell responses: the viable but non-culturable (VBNC) state (i.e. <0.1 colony forming unit ml-1) at 5 degrees C, and starvation (i.e. maintenance of culturability of the population) at 18 degrees C. The latter remained rod shaped and, after 40 days' incubation, presented a 47-58% reduction in the number of cells attached to chitin, a 48-53% reduction in the number of bacteria adhering to copepods, and a 48-54% reduction in the number of bacteria adhering to human cultured intestinal cells, compared to control cells not suspended in ASW. Bacteria suspended in ASW at 5 degrees C became coccoid and, after 40 days, showed 34-42% fewer cells attached to chitin, 52-55% fewer adhering to copep-ods, and 45-48% fewer cells adhering to intestinal cell monolayers, compared to controls. Sarkosyl-insoluble membrane proteins that bind chitin particles were isolated and analysed by SDS-PAGE. After 40 days incubation in ASW at both 5 degrees C and 18 degrees C vibrios expressed chitin-binding ligands similar to bacteria harvested in the stationary growth phase. It is concluded that as vibrios do not lose adhesive properties after long-term exposure to ASW, it is important to include methods for VBNC bacteria when testing environmental and clinical samples for purposes of public health safety.
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000378:metabolism; D018938:Caco-2 Cells; D002448:Cell Adhesion / Q000502:physiology*; D002686:Chitin / Q000378:metabolism; D033342:Copepoda / Q000378:metabolism / Q000382:microbiology; D003902:Detergents / Q000378:metabolism; D006801:Humans; D007413:Intestinal Mucosa / Q000166:cytology / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D012521:Sarcosine / Q000031:analogs & derivatives* / Q000378:metabolism; D012623:Seawater; D013696:Temperature; D014734:Vibrio cholerae / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins; D003902:Detergents; D008565:Membrane Proteins; D002686:Chitin; C025231:sarkosyl; D012521:Sarcosine