Evaluation of the oxolinic acid-esculin-azide medium for the isolation andenumeration of faecal streptococci in a routine monitoring programme for bathing waters

m-Enterococcus agar (m-Ent) has been generally considered the reference med ium for faecal streptococci in bathing waters. However, it shows several sh ortcomings,and therefore it is important to test newly developed media that can guarantee more precise results. In this sense, the recently described oxolinic acid - esculin - azide: agar medium (OAA) and m-enterococcus agar (m-Ent) were comparatively evaluated for the detection of faecal streptococ ci from seawater and fresh water. The OAA medium showed a significantly hig her relative recovery percentage and specificity for both types of water th an m-Ent. A similar spectrum of species was recorded from both media, Enter ococcus faecium being predominant in fresh water and Enterococcus faecalis, in seawater. The superior performance of the OAA medium in both types of b athing waters, added to the fact that it does not require the use of comple mentary confirmative tests, makes this medium an excellent candidate to be employed for monitoring programmes.