Rohonczy K.,Wessling Hungary Ltd. |
Rantsiou K.,University of Turin |
Cocolin L.,University of Turin
Journal of Food Safety | Year: 2013
Campylobacter spp. are currently the bacterial foodborne pathogen that causes the highest number of gastrointestinal diseases in developed countries, according to the World Health Organization. The aim of this study was to compare the performance of four Campylobacter enrichment broths: Bolton broth, Bolton broth with blood, Preston broth and Preston broth with blood using both culture-dependent methods and an optimized quantitative polymerase chain reaction (qPCR) protocol. The enrichment in Bolton broth with blood allowed most positive samples for Campylobacter jejuni to be detected when 40 chicken meat samples from the market were tested. Correlation between cultural methods and molecular methods was poor. Only in a few cases could C.jejuni and Campylobacter spp. be identified by PCR. Out of 480 colonies isolated throughout the enrichment process, only seven colonies could be identified as Campylobacter spp., three of which were C.jejuni. Enrichment of chicken meat samples with Bolton broth added with blood, coupled with qPCR resulted to be the most suitable method to detect samples contaminated with C.jejuni. Practical Applications: Detection and identification of Campylobacter spp. in food is still a challenge and there is lack of consensus on the methodology that should be used in order to recover these fastidious microorganisms. The application of molecular methods, such as the amplification of a target gene sequence by PCR, in order to rapidly and inequivocally detect and identify foodborne pathogens in foodstuff, offers a valid alternative to traditional microbiological testing. In this study, we investigated the performances of combined enrichment strategies with a specific C.jejuniqPCR protocol. The molecular approach resulted to be superior with respect to traditional plating and was able to detect a higher number of C.jejuni positive samples. Among the enrichment broths tested, Bolton broth added with blood resulted to be the most suitable for the detection of Campylobacter spp. in poultry meat. © 2013 Wiley Periodicals, Inc.
Farkas Z.,National Food Chain Safety Office |
Slate A.,North Carolina State University |
Whitaker T.B.,North Carolina State University |
Suszter G.,Wessling Hungary Ltd.
Journal of Agricultural and Food Chemistry | Year: 2015
The uncertainty of pesticide residue levels in crops due to sampling, estimated for 106 individual crops and 24 crop groups from residue data obtained from supervised trials, was adjusted with a factor of 1.3 to accommodate the larger variability of residues under normal field conditions. Further adjustment may be necessary in the case of mixed lots. The combined uncertainty of residue data including the contribution of sampling is used for calculation of an action limit, which should not be exceeded when compliance with maximum residue limits is certified as part of premarketing self-control programs. On the contrary, for testing compliance of marketed commodities the residues measured in composite samples should be greater than or equal to the decision limit calculated only from the combined uncertainty of the laboratory phase of the residue determination. The options of minimizing the combined uncertainty of measured residues are discussed. The principles described are also applicable to other chemical contaminants. © 2015 American Chemical Society.
Rohonczy K.,Wessling Hungary Ltd. |
Zoller L.,Wessling Hungary Ltd. |
Hermann Z.,Wessling Hungary Ltd. |
Fodor A.,Wessling Hungary Ltd. |
And 2 more authors.
Acta Microbiologica et Immunologica Hungarica | Year: 2014
The aim of this study was to compare an enzyme-linked fluorescent assay (ELFA)-based and two real-time polymerase chain reaction (PCR) methods with the results of the standard culture-based method EN ISO 6579:2002 (bacteriological standard method used in the European Union) for the detection of Salmonella spp. in raw chicken meat. Our investigations were performed on 141 poultry samples sorted from supermarkets.Relative accuracy, relative specificity and relative sensitivity were determined. According to the ISO 16140:2003 criteria for validation of alternative microbiological methods, the ELFA-based method (VIDAS ICS2 + SLM), and real-time PCR methods (TaqMan, Bax) were comparable to the reference standard method for the detection of Salmonella spp. in chicken meat. The use of these methods provide results within 48 hours with high sensitivity (100%). The TaqMan real-time PCR showed a relative specificity of 98% and both of the real-time PCR methods presented 100%.The VIDAS ICS2 + SLM and the Bax real-time PCR methods showed the highest relative accuracy (100%) and 99% in case of the TaqMan method. In conclusion, both the real-time PCR and the ELFA-based assay can be used as a rapid and user-friendly diagnostic method for detection of Salmonella spp. in chicken meat samples.