Dynamics of non-O1 Vibrio cholerae and fecal coliforms in experimental stabilization ponds in the arid region of Marrakesh, Morocco, and the effect of pH, temperature, and sunlight on their experimental survival.

We studied the spatial-temporal dynamics of non-O1 Vibrio cholerae numbers at a stabilization pond treatment plant. This bacterium's seasonal dynamics were the inverse of those of fecal coliforms, with high levels in hot periods and low levels in cold periods. Stabilization pond treatment did not significantly reduce non-O1 V. cholerae numbers between the system's inflow and outflow points. In contrast, fecal coliforms were reduced by 98.95% in hot periods and by 94.91% in cold periods. Significant rho coefficient values for the Spearman correlation between numbers of non-O1 V. cholerae and temperature and pH of 0.91 and 0.76, respectively, were found at the system's outflow point. An experimental study of the effects of pH, temperature, and sunlight on the survival of non-O1 V. cholerae and fecal coliforms confirmed the inverse behaviour of the two bacterial groups noted in the stabilization ponds. Alkaline pH values of 8 and 8.8 promoted the survival of non-O1 V. cholerae and inhibited that of Escherich...