Detection of food hazards in foods: comparison of real time polymerase chain reaction and cultural methods


Submitted: 23 November 2015
Accepted: 11 December 2015
Published: 28 January 2016
Abstract Views: 2069
PDF: 1247
HTML: 232
Publisher's note
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.

Authors

Foodstuffs should not contain microorganisms or their toxins or metabolites in quantities suggesting an unacceptable risk for human health. The detection of food hazards in foods is performed by several tests that produce results dependent on the analytical method used: an analytical reference method, defined as standard, is associated with each microbiological criterion laid down in Regulation 2073/2005/EC, but, analytical methods other than the reference ones, in particular more rapid methods, could be used. Combined screening methods performed by real time-polymerase chain reaction (RT-PCR) are currently validated as alternative methods according to the ISO 16140:2003 and certified by the Association Française de Normalisation. However, the positive results obtained with these alternative methods, the investigated molecular relations that resulted positive have to be confirmed with cultural methods using the same enrichment media in which the molecular screening was performed. Since it is necessary to assess if these testing schemes provide equivalent guarantees of food safety, the aim of this retrospective study is to analyse the data collected, from 2012 to 2014 by Emilia Romagna Region in the field of Piano Regionale Alimenti (Food Regional Plan) during official controls monitoring food samples of animal and other than animal origin. Records performed by combined methods of molecular screening of Salmonella spp., Listeria monocytogenes and thermophilic Campylobacter and cultural confirmation results were gathered together and the results were compared in order to assess the sensitivity of the methods. A total of 10,604 food samples were considered in this study: the comparison of the data revealed that the RT-PCR method detected Salmonella, L. monocytogenes, and thermophilic Campylobacter in 2.18, 3.85 and 3.73% of the samples, respectively, whereas by using cultural method these pathogens were isolated in 0.43, 1.57 and 1.57% of samples, respectively. In spite of the use of the same enrichment broth, the RT-PCR method disclosed a percentage of positive samples that was negative to cultural examination ranging between 20 and 43%, with a PCR/culture ratio between 2.37 to 5.00. In conclusion, the results of this study pose a doubt about the sensitivity of the official cultural methods regarding the isolation of the three investigated foodborne pathogens. Moreover this study may be a useful tool for veterinary authorities to assess appropriate sampling plans to control the risk relating to the consumption of contaminated foods.

Supporting Agencies

none

1.
Bonilauri P, Bardasi L, Leonelli R, Ramini M, Luppi A, Giacometti F, Merialdi G. Detection of food hazards in foods: comparison of real time polymerase chain reaction and cultural methods. Ital J Food Safety [Internet]. 2016 Jan. 28 [cited 2024 Mar. 29];5(1). Available from: https://www.pagepressjournals.org/ijfs/article/view/ijfs.2016.5641

Downloads

Download data is not yet available.

Citations