Performance characteristics of temperature-modified ISO 9308-1 method for the enumeration of Escherichia coli in marine and inland bathing waters

Data present the results obtained during establishing of performance characteristics of temperature-modified ISO 9308-1:2014 method. The incubation temperature was changed to 44±0.5°C after the 4-hour resuscitation period at 36±2 °C. Elevated incubation temperature significantly suppressed the growth of thermo-intolerant bacteria and enhanced the selectivity with no negative effect on E. coli recovery. All achieved performance characteristics met the requirements and recommendations set out in ISO 13843:2017 standard. Finally, Chromogenic coliform agar was assessed as a suitable medium for the reliable enumeration of E. coli in bathing water when incubated 17-19 hours at 44±0.5 °C after the 4-5 hours resuscitation period at 36±2 °C.