Occurrence of Vibrio parahaemolyticus and Vibrio alginolyticus in marine and estuarine bathing areas in Danish coast.

From seventeen sites in three marine and two estuarine bathing areas at the Danish coast water samples were collected during the period from May to November 1979. Total bacterial counts were performed on blood agar. The prevalence of Vibrio parahaemolyticus and Vibrio alginolyticus in 100 ml water samples using the filter membrane technique and TCBS agar plates was investigated with the possible correlation to water temperature and salinity. Only five strains of V. parahaemolyticus were isolated, two from marine and three from estuarine water. V. alginolyticus was isolated in 8.33 and 15.63 per cent, in relation to the total bacterial count/100 ml on TCBS agar, in marine and estuarine water samples, respectively. The maximum was registered in June and July, corresponding with the highest temperatures recorded (12-18 degrees C). V. alginolyticus should be considered a widely distributed bacterium in Danish coastal areas and could be regarded as a bacterial indicator of hygienic and public health importance.