Circulation of adenovirus and other viruses in urban drainage channels: an environmental surveillance in Belém, Amazon region, Brazil.

Urban channels in amazon cities are very polluted, with garbage and sewage disposal in these aquatic environments, favoring the high dissemination of waterborne viruses such as human adenovirus (HAdV). The aim of this study was to perform the detection and molecular characterization of adenovirus in urban channels and in a wastewater treatment plant located in a metropolitan city in the Amazon. Additionally, metagenomic analyses were performed to assess viral diversity. Samples were concentrated by organic flocculation, analyzed by quantitative real time PCR (qPCR) and sequenced (Sanger e next generation sequencing). Cell culture was performed to verify the viability of HAdV particles. A total of 104 samples were collected, being the HAdV positivity of 76% (79/104). Among the positive samples, 29.1% (23/79) were characterized as HAdV-F40 (87%, 20/23), HAdV-F41 (8.7%, 2/23), and HAdV-B (4.3%, 1/23). Average precipitation rates ranged from 163 to 614 mm, while the pH ranged from 6.9 to 7.6. Eight positive samples were inoculated into A549 cells and in 4 of these, was observed changes in the structure of the cell monolayer, alteration in the structure of the cell monolayer was observed, but without amplification when analyzed by PCR. The metagenomic data demonstrated the presence of 14 viral families, being the most abundant: Myoviridae (41% of available reads), Siphoviridae (24.5%), Podoviridae (14.1%), and Autographiviridae (6.9%) with more than 85% of the total number of identified reads. This study reinforcing that continuous surveillance may contribute to monitoring viral diversity in aquatic environments and provide early warning of potential outbreaks.