title: Presence and fate of coliphages and enteric viruses in three wastewater treatment plants effluents and activated sludge from Tunisia.
abstract: OBJECTIVE
  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.
  
  
  CONCLUSIONS
  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.
  
  
  CONCLUSIONS
  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.affiliation: Unité de Microbiologie et de Biologie Moléculaire, CNSTN, Technopôle de Sidi Thabet, 2020 Sidi Thabet, Tunisia.
authors.forename: Sihem
authors.initials: S
authors.lastname: Jebri
authors.forename: Juan
authors.initials: J
authors.lastname: Jofre
authors.forename: Insaf
authors.initials: I
authors.lastname: Barkallah
authors.forename: Mouldi
authors.initials: M
authors.lastname: Saidi
authors.forename: Fatma
authors.initials: F
authors.lastname: Hmaied
mesh_terms: D003090:Coliphages / Q000235:genetics / Q000378:metabolism*; D004770:Enterovirus / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D012367:RNA, Viral / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012722:Sewage / Q000032:analysis / Q000821:virology*; D014416:Tunisia; D014865:Waste Disposal, Fluid / Q000379:methods; D014871:Water Microbiology
chemical_list: D012367:RNA, Viral; D012722:Sewage