Occurrence and Resistance of Pathogenic Bacteria Along the Tietê River Downstream of São Paulo in Brazil

The load of pathogenic bacteria, their fate and their dangerousness in the Tiete River were assessed along 100 km starting from the city of Sao Paulo, Brazil. The data were compared with those from two German rivers. High loads of pathogens were found in the Tiete River near the city of Sao Paulo (Escherichia coli 0157:H7, Shigella flexneri, and Shigella boydii), which were absent 30 km downstream of Sao Paulo. The antibiotic resistances observed in the Tiete river were rather low and decreased after the major input in Sao Paulo to significantly lower levels about 30 km downstream. While the Brazilian isolates were more susceptible for ampicillin than the German ones, the reverse was observed for gentamycin. For optimal control of infections in humans critical areas where these bacteria survived longer and their elimination mechanisms should be identified as well as the extent and the origin of antibiotic resistance should be determined.