Characterization of Environmental and Cultivable Antibiotic-Resistant Microbial Communities Associated with Wastewater Treatment

Bacterial resistance to antibiotics is a growing global concern, threatening human and environmental health, particularly among urban populations. Wastewater treatment plants (WWTPs) are thought be “hotspots” for antibiotic dissemination. The conditions of WWTPs, in conjunction with the persistence commonly used antibiotics, may favor selection transfer genes bacterial WWTPs provide an important ecological niche examine spread resistance. We heterotrophic plate count methods identify phenotypically resistant cultivable portions these communities characterized composition culturable subset Resistant taxa were more abundant raw sewage wastewater before biological aeration stage. While some antibiotic-resistant bacteria (ARB) detectable downstream treated release, organisms not enriched relative effluent-free upstream water, indicating efficient removal during treatment. Combined culture-dependent -independent analyses revealed stark difference community between fractions source material, irrespective culturing conditions. Higher proportions populations recovered than predicted by widely accepted 1% culturability paradigm. These results represent baseline abundance compositional data ARB reference future studies addressing dissemination associated ecosystems.