Survival of enteric bacteria and coliphage MS2 in pure human urine

The survival of Escherichia coli, Salmonella enterica serovar Typhimurium, Enterococcus faecalis and coliphage MS2 was studied in stored, fresh and diluted (1 : 1) human urine at 15 and 30 degrees C.

Survival rate was studied by the plate count method. All the organisms showed rapid inactivation in stored urine, but they survived better in diluted and fresh urine. The high pH level and temperature were the major factors found to influence the survival of the micro-organisms with the survival rate being higher at 15 degrees C than at 30 degrees C.

The destruction of all micro-organisms in stored urine required <1 week at 30 degrees C. Thus, the storage of urine is a useful way to reduce the risk of contamination while using urine as a fertilizer.

The urine fertilization is aimed for the developing countries and the high temperatures in these countries may hasten the destruction of micro-organisms in urine. On the contrary, a higher survival rate of these organisms in fresh and diluted urine is a public health concern because the dilution of urine with water is likely to happen during flushing.