[Survival of Vibrio cholerae non-O1 in river sediment during cold season].

To assess the existence of Vibrio cholerae non-O1 in the environment water system during the cold season, the organism was incubated in both river sediment or terrestrial soil as particle matter-water (1:1) suspension. The low temperature condition was set to 5 degrees and 10 degrees C. At 5 degrees C, V. cholerae non-O1 did not grow in any medium, sediment and soil. At 10 degrees C, the decrease of the number of organisms was delayed in river sediment as compared with peptone medium. At 30 degrees C, the organism grew in river sediment and its extract solution. In soil, the organism was decreased immediately under low temperature. Though the number of organisms was decreased temporarily in soil, its number was maintained within 14 days at 30 degrees C. But in the extract solution from soil, the organism was decreased immediately under 5 degrees, 10 degrees, 20 degrees, 30 degrees C. It showed that survival of V. cholerae non-O1 was maintained in particle substances contained water. These results suggested that V. cholerae non-O1 would be able to exist in river sediment during the cold season.