DETECTION OF LEGIONELLA SPECIES IN SEWAGE AND OCEAN WATER BY POLYMERASE CHAIN-REACTION, DIRECT FLUORESCENT-ANTIBODY, AND PLATE CULTURE METHODS

Legionella spp. are ubiquitous in most environmental water sources; ho wever, sewage treatment plants have not been examined as potential env ironmental reservoirs for these bacteria. This study used polymerase c hain reaction, direct fluorescent-antibody staining, and culture metho ds to examine raw and treated sewage, ocean-receiving waters, and near shore coastal environments for the presence of Legionella pneumophila and other Legionella spp. The study concluded that Legionella spp. are present in all phases of sewage treatment and that population numbers do not significantly decline through the treatment process.. Ocean-re ceiving waters located 5 miles offshore, where the treated sewage is d ischarged, were found to contain Legionella spp., but ocean water betw een the discharge site and coastal bathing beaches was negative. This suggests that the Legionella spp. from the ocean discharge site were n ot reaching the nearshore beach waters. A flood control channel and ri ver that entered the ocean were found to contain Legionella spp., and a nearby beach swimming area was also found to be positive, suggesting that land runoff from the flood control channel and river were the so urce of the Legionella spp. in the beach water samples that tested pos itive.