Survival of Vibrio cholerae O1 on plastic materials.

Survival of environmental and clinical strains of Vibrio cholerae O1 was studied on glass and on two varieties of plastic materials. V. cholerae survived at least 2 days on glass, but was not recovered from polystyrene spoons after 15-20 min. Escherichia coli survived for at least 2 days on both glass slides and plastic spoons. Extracts, 10 and 50% (w/v) of ground plastic spoons in isotonic saline water, inactivated 10(4) vibrios in less than 2 h. Isotonic saline water rinses from polyethylene bags inactivated (0% survival) 15 out of 23 strains of V. cholerae in 1 h. A strain of V. cholerae (100-200 CFU/ml) directly suspended in 25 ml of isotonic saline per bag and maintained at 20 degrees C was progressively inactivated. The number of viable cells diminished 95% in 4 h in bags taken from non-sterile rolls. In sterile bags the decrease was 44% and 93% after 4 and 24 h, respectively. A variability up to 50% was observed in the antibacterial effect among the different bags, either sterile or taken from non-sterile rolls. These decreases in V. cholerae viability may result in false negative reports if water samples are collected and carried out in plastic bags.