Detection of Enteric Viruses and Bacterial Indicators in a Sewage Treatment Center and Shallow Water Bay

Abstract

The incidence of enteric viruses in treated wastewater and their potential release into the environment or use for agriculture are very critical matters in public health. In our study, PCR (polymerase chain reaction) analysis of enteric viruses was performed on 59 samples of influents and effluents collected from Tubli wastewater treatment plant (Water Pollution Control Center (WPCC)) and Tubli Bay, where the effluents were discharged, in Kingdom of Bahrain during two sampling periods. Four clinically essential waterborne enteric viruses were examined: enterovirus (EV), hepatitis A virus (HAV), astroviruses (AV), and rotaviruses (RV) and compared to standard bacterial and bacteriophages indicators of fecal pollution. Detection rates of EV, AV, HAV, and RV in the influent samples were 100%, 75%, 12.5%, and 12.5%, respectively, while 50% of the effluent samples from Tubli WPCC contained only EV RNA. None of the tested enteric viruses could be detected in any of the samples collected directly from Tubli Bay. Effluent samples from Tubli plant did not show significant seasonal differences. Since detection of enteric viruses genome does not necessarily indicate infectivity, the infectivity of these viruses was evaluated through isolation and growth of indictor bacteria and bacteriophages. High concentration of fecal bacteriological indicators was detected in all effluents samples (100%): 3.20 × 103 cfu/mL for E. coli, 1.32 × 103 cfu/mL for Salmonella spp., and 1.92 × 103 cfu/mL for Shigella spp. E. coli and Salmonella specific bacteriophages were also detected in the effluent samples in high titers. The combined results of PCR and bacterial enumeration point to a probable public health risk via the use of these wastewaters in agriculture or their discharge into the sea. Continuous surveillance of viral and bacterial prevalence and their resistance to sewage disinfection procedures could contribute to a better control of risks associated with the recycling of effluent wastewater and its release into the environment.

Molecular characterization of enterovirus detected in cerebrospinal fluid and wastewater samples in Monastir, Tunisia, 2014–2017

“…In addition, our study showed the presence of EVs not only in raw but also in treated wastewater (in almost 30% of these samples). Other studies also documented higher detection rate of EVs from both raw and treated wastewater [ 47 , 48 ],…”

Detection and Phylogenetic Analysis of Hepatitis A Virus in the Wastewater Treatment Plant of Ekbatan Town in Tehran, Iran

“…As the largest biological sink, sewage contains a pool of infectious agents as well as other organic and non-organic materials. A wide variety of infectious agents, including bacteria, fungi, parasites, and viruses can be found in sewage, which makes it an important transmission vehicle (2). Enteric viruses, including some members of rotaviruses, enteroviruses, astroviruses, noroviruses, adenoviruses, hepatitis A virus (HAV), and hepatitis E virus, are transmitted mainly through the fecal-oral route (3).…”

Epidemiology of Extended-spectrum beta-lactamase-producingEscherichia coliat the human-animal-environment interface in Wakiso district, Uganda

“…Indeed, there is a lot of undetected community carriage and transmission of ESBL-PE at the human-animal-environment interface [15] even though there is inadequate local evidence for this. Such insufficient evidence may not competently inform prevention and control strategies including policies to govern management of AMR in the LMICs [16,17].…”