Detection of human fecal contamination by nifH gene quantification of marine waters in the coastal beaches of Rio de Janeiro, Brazil

Abstract

The identification of fecal pollution in aquatic ecosystems is one of the requirements to assess the possible risks to human health. In this report, physicochemical parameters, Escherichia coli enumeration and Methanobrevibacter smithii nifH gene quantification were conducted at 13 marine waters in the coastal beaches of Rio de Janeiro, Brazil. The pH, turbidity, dissolved oxygen, temperature, and conductivity, carried out by mobile equipment, revealed varied levels due to specific conditions of the beaches. The bioindicators' enumerations were done by defined substrate method, conventional, and real-time PCR. Six marine beach sites (46 %) presenting E. coli levels in compliance with Brazilian water quality guidelines (<2500 MPN/100 mL) showed nifH gene between 5.7 × 10 to 9.5 × 10 copies. L revealing poor correlation between the two approaches. To our knowledge, this is the first inquiry in qPCR using nifH gene as a biomarker of human-specific sources of sewage pollution in marine waters in Brazil. In addition, our data suggests that alternative indicator nifH gene could be used, in combination with other markers, for source tracking studies to measure the quality of marine ecosystems thereby contributing to improved microbial risk assessment.

Surveillance of human enteric viruses in coastal waters using concentration with methacrylate monolithic supports prior to detection by RT-qPCR

“…Salinity was rather constant during the studied year and higher than at the salinity/pollution gradient, which shows that less inputs of fresh water affect these locations and consequently less pollution is expected ( George et al, 2002 ; S.S. Oliveira et al, 2016 ; Turk et al, 2007 ). In Fig.…”

Antibiotic resistance in surface waters from a coastal lagoon of Southern Brazil under the impact of anthropogenic activities

“…Thus, the ARB count variance in this point appeared to be influenced by faecal pollution, especially in the peak season, as a possible effect of the intense anthropogenic activities observed in this period. Landscape changes as a consequence of urbanization have been associated to impact on bacterial communities modifications, including the increasing in both thermotolerant coliforms (Garbossa et al, 2017;Oliveira et al, 2016) and ARB abundance (Wang et al, 2016;Yang et al, 2017).…”

“…Levels of antimicrobial contamination have already been detected in water bodies of Brazil (Quadra et al, 2017), but bacterial resistance has been poorly studied in these environments (Nascimento and Araújo, 2014;da Costa Andrade et al, 2015;Monteiro et al, 2016;Oliveira et al, 2016). In this way, this study aims to evaluate the presence of antibiotic resistant bacteria (ARB) in surface waters of Tramandaí Lagoon and whether it varies according to the presence of different anthropic disturbances.…”

Insights on the particle-attached riverine archaeal community shifts linked to seasons and to multipollution during a Mediterranean extreme storm event

“…Mbt. smithii (OTU3) was the second most abundant key player, which is known to be derived from the human gastrointestinal tract (Miller et al 1982;Oliveira et al 2016) and identified as a potential indicator of sewage (Johnston et al 2010;McLellan and Eren 2014). The third most abundant OTU41 was affiliated with Msa.…”