Improved m-Enterococcus agar for counting faecal streptococci in sea water.

An improved medium for counting faecal streptococci in sea water is described. The medium was based on m-Enterococcus agar with the addition of 20 mg/l colistin sulphate and 10 mg/l oxolinic acid. There was no inhibition of faecal streptococci counts from sea water by the addition of these antibiotics. No significant differences were observed between the mean colony counts on media before and after identification of the colonies. The qualities of this improved medium make it the logical choice for counting faecal streptococci in sea water.