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

BLANCO FERNANDEZ, MARIA DOLORES; MELINA ELIZABETH BARRIOS; ROBERTINA VIVIANA CAMMARATTA; CAROLINA TORRES; OSCAR ALBERTO TABOGA; VIVIANA ANDREA MBAYED

APPLIED MICROBIOLOGY AND BIOTECHNOLOGY

SPRINGER

Lugar: Berlin; Año: 2017 vol. 101 p. 4289 - 4298

0175-7598

Enteric viruses are pathogens associated with foodand waterborne outbreaks. The recovery of viruses from foodor water samples is affected by the procedures applied to detect and concentrate them. The incorporation of an internalprocess control virus to the analyses allows monitoring theperformance of the methodology. The aim of this study wasto produce a recombinant adenovirus (rAdV) and apply ittogether with bacteriophage PP7 as process controls. TherAdV carries a DNA construction in its genome to differentiate it from wild-type adenovirus by qPCR. The stability ofboth control viruses was evaluated at different pH conditions.The rAdV was stable at pH 3, 7, and 10 for 18 h. 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 h. Threevirus concentration methods were evaluated: hollow-fiber tapwater ultrafiltration, wastewater ultracentrifugation, andelution-PEG precipitation from lettuce. Total and infectiousviruses were quantified and their recoveries were calculated.Virus recovery for rAdV and PP7 by ultrafiltration showed awide range (2.10?84.42 and 13.54?84.62%, respectively),whereas that by ultracentrifugation was 5.05?13.71 and6.98?13.27%, respectively. The performance of ultracentrifugation to concentrate norovirus and enteroviruses present insewage was not significantly different to the recovery of control viruses. For detection of viruses from lettuce, genomiccopies of PP7 were significantly more highly recovered thanadenovirus (14.74?18.82 and 0.00?3.44%, respectively). Therecovery of infectious virus particles was significantly affected during sewage ultracentrifugation and concentration fromlettuce. The simultaneous use of virus controls with dissimilarcharacteristics and behaviors might resemble different entericviruses.