Longevity of pathogenic bacteria especially salmonella in cistern water

Cistern-collected rain water which is used as process water for toilet flus hing, cleaning purposes, garden irrigation and linen washing, was experimen tally contaminated with pathogenic bacteria, Salmonella enteritidis, Yersin ia enterocolitica and Campylobacter jejuni. The longevity of those pathogen s was investigated considering different temperatures and contents of organ ic materials. Neither Salmonella enteritidis, Yersinia enterocolitica nor Campylobacter j ejuni are able to grow at temperatures of 5 degrees C, 15 degrees C, 20 deg rees C or 37 degrees C. The most sensitive pathogen was Campylobacter jejun i which showed rapidly decreasing of colony counts at 15 degrees C as compa red with Yersinia enterocolitica or Salmonella enteritidis. For Salmonella enteritidis the decrease of bacterial concentrations was hig her at 37 degrees C than at 5 degrees C. Increasing the concentrations of organic compounds by addition of bacteriol ogical pepton or addition of extrem amounts of pidgeon feces lowers the rat e of bacterial death but an increase in colony counts could not be observed at the different temperatures investigated. The elimination of salmonella is supported if the cisterns are layered with a biofilm and sediment. So it could be confirmed, that raised amounts of organic material, pidgeon feces together with optimal temperatures which can be observed accidentaly in rain water cisterns can not enhance growth of enteropathogenic bacteria.