Recovery tests of cytopathogenic viruses from artificially contaminated food samples
Main Article Content
Keywords
enteroviruses, food analysis, virus detection
Abstract
The artificial contamination tests were carried out by using a Coxsackie B5 virus of known titration to contaminate vegetable food products (lettuce and berries). The experimental protocol was divided basically into two phases: elution with alkaline pH buffer solution and following concentration of viral particles recovered by using PEG8000 (polyethylene glycol). A third phase of purification with chloroform was introduced between these two steps in order to assess its effect on the yield of the final recovery, and tests were performed in parallel with both the protocols to compare them in terms of recovery efficiency. Elution phase proved to be the most critical, since the viral recovery from food samples during this phase resulted moderate (2.95% and 2.16% respectively in tests without and with chloroform purification phase), data already observed in previous studies. The final concentration phase with PEG8000 recorded average recoveries equalling 0.29% in tests without chloroform and equalling 3.97% in tests with purification phase, thus showing a significant improvement with a lesser interference by the organic material.
References
Bouchriti N., Goyal S. (1992) Evaluation of three methods for the concentration of Poliovirus from oyster.Microbiological,15,403–408.
Bresee J.S., Widdowson M.A., Monroe S.S., Glass R.I. (2002) Foodborne viral gastroenteritis: challenges and opportunities.Clin. Infect. Dis.,35, 748–753.
Butot S., Putallaz T., Sa ?nchez G. (2007) Procedure for rapid concentration and detection of enteric viruses from berries and vegetables.Appl. Environ. Microbiol.,73, 186–192.
Dubois E., et al. (2006) Intenal-laboratory validation of a concentration method adapted for the enumeration of infectious F-specific RNA coliphage, enterovirus, and hepatitis A virus from inoculated leaves of salad vegetables.Int. J. FoodMicrobiol.,108, 164–171.
Durkop J. ‘‘Virus contamination of surface water’’. In: Trends in Microbial Ecology proceeding of the Sixth InternationalSymposium on Microbial Ecology. Barcelona, 6–11 September 1992
Frankhauser R.L., Monroe S.S., Noel J.S., Humphrey C.D., BreseeJ.S., Parashar U.D., Ando T., Glass R.I. (2002) Epidemiologic and molecular trends of Norwalk-like viruses associated with outbreaks of gastroenteritis in the U.S.J. Infect. Dis.,186, 1–7.
Katzenelson E., Fattal B., Hostovesky T. (1976) Organicflocculation: an efficient second-step concentration method for the detoction of viruses in tap water.Appl. Environ.Microbiol.,32, 638–639.
Kim H.Y., Kwak I.S., Hwang I.G., Ko G. (2008) Optimization of methods for detecting norovirus on various fruit.J. Virol. Methods p. 25.
Le Guyader F.S., Schultz A.C., Haugarreau L., Croci L., Manula L.,Duizer E., Lodder-Verschoor F., van Bonsdorff C.H., SuffrediniE., van der Poel W.M., Reymundo R., Koopmans M. (2004) Round-robin comparison of methods for the detection of human enteric viruses in lettuce.J. Food Prot.,67, 2315–2319.
Park Y., Cho Y.H., Jee Y., Ko G. (2008) Immunomagnetic separation combined with real-time reverse transcriptase PCR assays for detection of norovirus in contaminated food.Appl.Environ. Microbiol.,74, 4226–4230.
Rzezutka A., Alotaibi M., D’Agostino M., Cook N. (2005) A centrifugation-based method for extraction of norovirus from raspberries.J. Food Prot.,68, 1923–1925.
Rzezutka A., D’Agostino M., Cook N. (2006) An ultracentrifugation-based approach to the detection of hepatitis A virus in soft fruits.Int. J. Food Microbiol.,108,315–320.