PURPOSE: The role of water in the transmission of infectious diseases is well defined; it may act as a reservoir of different types of pathogens. Enteric viruses can survive and persist for a long time in water, maintaining infectivity in many instances. This suggests the need to include virus detection in the evaluation of the microbiological quality of waters. METHODS: In this study, enteric viruses (enteroviruses and hepatitis A virus (HAV)) were investigated by RT-PCR and coliphages (known as indicators of viral contamination) were enumerated with the double-layer technique agar in effluents and sewage sludge from three Tunisian wastewater treatment plants. RESULTS AND DISCUSSION: The molecular detection of enteric viruses revealed 7.7% of positive activated sludge samples for enteroviruses. None of the samples was positive for HAV. Molecular virus detection threshold was estimated to be 10(3) PFU/100 ml. All samples contained high concentrations of coliphages except those of dry sludge. Reductions in the concentrations of bacteriophages attained by the wastewater treatment plants are of the order of magnitude as reductions described elsewhere. Peak concentrations in raw wastewater were associated with winter rains and suspended materials rate in analysed samples. Our data which is the first in North Africa showed that similar trends of coliphages distribution to other studies in other countries. CONCLUSION: No clear correlation between studied enteric viruses and coliphages concentration was proved. Coliphages abundance in collected samples should raise concerns about human enteric viruses transmission as these residues are reused in agricultural fields.
PURPOSE: The role of water in the transmission of infectious diseases is well defined; it may act as a reservoir of different types of pathogens. Enteric viruses can survive and persist for a long time in water, maintaining infectivity in many instances. This suggests the need to include virus detection in the evaluation of the microbiological quality of waters. METHODS: In this study, enteric viruses (enteroviruses and hepatitis A virus (HAV)) were investigated by RT-PCR and coliphages (known as indicators of viral contamination) were enumerated with the double-layer technique agar in effluents and sewage sludge from three Tunisian wastewater treatment plants. RESULTS AND DISCUSSION: The molecular detection of enteric viruses revealed 7.7% of positive activated sludge samples for enteroviruses. None of the samples was positive for HAV. Molecular virus detection threshold was estimated to be 10(3) PFU/100 ml. All samples contained high concentrations of coliphages except those of dry sludge. Reductions in the concentrations of bacteriophages attained by the wastewater treatment plants are of the order of magnitude as reductions described elsewhere. Peak concentrations in raw wastewater were associated with winter rains and suspended materials rate in analysed samples. Our data which is the first in North Africa showed that similar trends of coliphages distribution to other studies in other countries. CONCLUSION: No clear correlation between studied enteric viruses and coliphages concentration was proved. Coliphages abundance in collected samples should raise concerns about human enteric viruses transmission as these residues are reused in agricultural fields.
Authors: Valerie J Harwood; Audrey D Levine; Troy M Scott; Vasanta Chivukula; Jerzy Lukasik; Samuel R Farrah; Joan B Rose Journal: Appl Environ Microbiol Date: 2005-06 Impact factor: 4.792
Authors: Ana Costán-Longares; Michel Montemayor; Andrey Payán; Javier Méndez; Joan Jofre; Rafael Mujeriego; Francisco Lucena Journal: Water Res Date: 2008-08-08 Impact factor: 11.236
Authors: Emna Nasri; Monia Machreki; Asma Beltifa; Sonia Aroui; Asma Ghorbel; Amina Saad; Anouar Feriani; Mohamed Ali Borgi; Lakhdar Ghazouani; Olivier Sire; José Luis Balcázar; Hedi Ben Mansour Journal: Environ Sci Pollut Res Int Date: 2017-07-13 Impact factor: 4.223