Comparison of internal process control viruses for detection of food and waterborne viruses

BLANCO FERNÁNDEZ, M.D.; BARRIOS, M.E.; CAMMARATA, RV.; TORRES, C.; TABOGA, O.; MBAYED, V.A.

APPLIED MICROBIOLOGY AND BIOTECHNOLOGY

SPRINGER

Año: 2017 vol. 101 p. 4289 - 4298

0175-7598

Enteric viruses are pathogens associated with food- and waterborne outbreaks. Therecovery of viruses from food or water samples is affected by the proceduresapplied to detect and concentrate them. The incorporation of an internalprocess control virus to the analyses allows monitoring the performance of themethodology. The aim of this study was to produce a recombinant adenovirus(rAdV) and apply it together with bacteriophage PP7 as process controls. TherAdV carries a DNA construction in its genome to differentiate it fromwild-type adenovirus by qPCR. The stability of both control viruses wasevaluated at different pH conditions. The rAdV was stable at pH 3, 7 and 10 for18 hours. PP7 infectious particles were stable at pH 7, and showed a 2.14-logreduction at pH 10 and total decay at pH 3 after 18 hours. Three virusconcentration methods were evaluated: hollow-fiber tap water ultrafiltration,sewage ultracentrifugation, and elution-PEG precipitation from lettuce. Totaland infectious viruses were quantified and their recoveries were calculated.Virus recovery for rAdV and PP7 by ultrafiltration showed a wide range: 2.10 ?84.42% and 13.54 - 84.62%, respectively, whereas that by ultracentrifugationwas 5.05 ? 13.71% and 6.98 ? 13.27% respectively. For detection of viruses fromlettuce, genomic copies of PP7 were significantly more highly recovered thanadenovirus: 14.74 ? 18.82% and 0 ? 3.44%, respectively. The recovery ofinfectious virus particles was significantly affected during sewageultracentrifugation and concentration from lettuce. The simultaneous use ofvirus controls with dissimilar characteristics and behaviors might resembledifferent enteric viruses.