title: A comparison of two extraction methods for the detection of Enteroviruses in raw sludge.
abstract: The aim of this study was to compare two viral extraction methods for the detection of naturally occurring Enteroviruses in raw sludge. The first method (M1) is based on an ultracentrifugation step. In the second one (M2), viral RNA was extracted directly after viral elution from suspended solids. Genomes of enteroviruses were quantified by a quantitative real time PCR (qRT-PCR) in sludge samples. Somatic coliphages and F-specific RNA phages, considered as viral indicators of enteric viruses in sludge, were enumerated by the double layer agar technique. Results showed that direct assay of RNA extraction yielded higher genomic copies of enteric viruses (with an average of 5.07Log10 genomic copies/100 mL). After the ultracentrifugation assay in the second method, genomic copies number decreases (with an average of 4.39Log10 genomic copies/100 mL). This can be explained by an eventual concentration of inhibitors existing in sludge samples. Phages enumeration results showed their presence in all sludge samples with an average of (5.69Log10 PFU/100 mL) for somatic coliphages and (4Log10 PFU/100 mL) for F-specific RNA phages. This emphasizes the use of somatic coliphages as viral indicators for enteroviruses in environmental samples and especially in raw sludge samples in wastewater treatment plants prior to agricultural use.
authors: Unité de Microbiologie et de Biologie Moléculaire, Centre National des Sciences et Technologies Nucléaires, Technopôle de Sidi Thabet, 2020 Sidi Thabet, Tunisia.
authors: Sihem
authors: S
authors: Jebri
authors: Unité de Microbiologie et de Biologie Moléculaire, Centre National des Sciences et Technologies Nucléaires, Technopôle de Sidi Thabet, 2020 Sidi Thabet, Tunisia. Electronic address: hmaiedfatma@yahoo.com.
authors: Fatma
authors: F
authors: Hmaied
authors: Barcelona University, Department of Microbiology, Diagonal 645, 08028 Barcelona, Spain.
authors: Francisco
authors: F
authors: Lucena
authors: Barcelona University, Department of Microbiology, Diagonal 645, 08028 Barcelona, Spain.
authors: Marià Eugenià
authors: ME
authors: Saavedra
authors: Unité de Microbiologie et de Biologie Moléculaire, Centre National des Sciences et Technologies Nucléaires, Technopôle de Sidi Thabet, 2020 Sidi Thabet, Tunisia.
authors: Mariem
authors: M
authors: Yahya
authors: Tunis Carthage University, Institut National Sciences Appliquées de Tunis, Laboratoire Ecologie Technologie Microbienne, BP 676, 1080 Tunis, Tunisia.
authors: Moktar
authors: M
authors: Hamdi
mesh_terms: D003090:Coliphages / Q000302:isolation & purification; D004770:Enterovirus / Q000302:isolation & purification*; D008967:Molecular Biology / Q000379:methods; D012317:RNA Phages / Q000302:isolation & purification; D012367:RNA, Viral / Q000302:isolation & purification; D012722:Sewage / Q000821:virology*; D014461:Ultracentrifugation / Q000379:methods; D019562:Viral Load / Q000379:methods*
chemical_list: D012367:RNA, Viral; D012722:Sewage
keywords: Enteroviruses; F-specific RNA phages; Sludge; Somatic coliphages; Viral extraction; qRT-PCR