Microbiological and physicochemical analysis of the coastal waters of southern Brazil

The aim of this study was to assess the impact of sewage discharge on coastal waters by evaluating the influence of physicochemical parameters on the presence of enteric microorganisms in seawater samples collected from 11 beaches in Florianopolis, Santa Catarina, Brazil, over a one-year period (August 2009 to July 2010). Samples were assessed for the presence of human adenoviruses (HAdV), polyomavirus (JCPyV), hepatitis A virus (HAV), and noroviruses (HuNoV GI and GII). Escherichia coli and physicochemical parameters (salinity, temperature, pH and dissolved oxygen) were also evaluated. From the 132 samples analyzed, 55% were positive for HAdV, 51.5% for HAV, 7.5% for HuNoV GI, 4.5% for HuNoV GII, and 3% for JCPyV. E. coli levels ranged from 8 to 1325 CFU/100 mL at all sites. The overall results highlight the problem of sewage discharge into coastal waters and confirm that there is no correlation between viral presence and bacterial contamination.

► Coastal water contamination by sewage discharge. ► No correlation between contamination by enteric viruses and fecal coliforms. ► High prevalence of positive samples for HAdV suggests that this virus is continuously excreted in the feces. ► Public investments for an adequate treatment of wastewater before the discharged into the sea its needed. ► Presence of viruses in seawater shown the importance of the monitoring of recreational areas and shellfish growing.