Abstract: Fecal indicator bacteria may not reflect the pollution of marine indigenous pathogenic bacteria. Therefore, the distribution of bacteriological indicators, including enterococcus, Vibrio parahaemolyticus, V. vulnificus and V. cholerae was analyzed during the peak swimming season in Dalian Fujiazhuang and Xinghai bathing beachs. The results showed that the exceeding standard rate of enterococcus was 58.2% (n=134), and the detection rates of virulence gene markers of V. parahaemolyticus, V. vulnificus and V. cholerae were 24.6%, 10.4% and 4.5% (n=134), respectively. These two bathing beaches were not only polluted by fecal pathogens, but also existed the pathogenic V. parahaemolyticus and V. vulnificus, besides, the pathogenic V. cholerae was also detected in Fujiazhuang bathing beach, which all pose potential risks to human health. The speed of wind, wave height and rainfall had great impacts on the distribution of enterococcus. Water temperature, air temperature, salinity and transparency were the main factors affecting the distribution of pathogenic V. vulnificus. pH and wave height had great influences on the distribution of V. parahaemolyticus. Due to the different ecological characteristics of enterococcus and Vibrio spp., we suggested that important pathogenic vibrio should be considered into the current routine monitoring of bathing beach.

Key words: enterococci, V. parahaemolyticus, V. vulnificus, V. cholerae, beach seawater, virulence gene marker