Virus hazards from food, water and the environment, their reservoirs and routes of transmission; Sampling methods and sampling strategies thereof, including the
1 March 2004 in Applied and Environmental Microbiology
We developed and assessed real-time PCR (RTi-PCR) assays for the detection and quantification of the food-borne pathogen Listeria monocytogenes and the closely related nonpathogenic species L. innocua . The target genes were hly and iap for L. monocytogenes and lin02483 for L. innocua . The assays were 100% specific, as determined with 100 Listeria strains and 45 non- Listeria strains, and highly sensitive, with detection limits of one target molecule in 11 to 56% of the reactions with purified DNA and 3 CFU in 56 to 89% of the reactions with bacterial suspensions. Quantification was possible over a 5-log dynamic range, with a limit of 15 target molecules and R2 values of >0.996. There was an excellent correspondence between the predicted and the actual numbers of CFU in the samples (deviations of <23%). The hly -based assay accurately quantified L. monocytogenes in all of the samples tested. The iap -based assay, in contrast, was unsuitable for quantification purposes, underestimating the bacterial counts by 3 to 4 log units in a significant proportion of the samples due to serovar-related target sequence variability. The combination of the two assays enabled us to classify L. monocytogenes isolates into one of the two major phylogenetic divisions of the species, I and II. We also assessed the new AmpliFluor technology for the quantitative detection of L. monocytogenes by RTi-PCR. The performance of this system was similar to that of the TaqMan system, although the former system was slightly less sensitive (detection limit of 15 molecules in 45% of the reactions) and had a higher quantification limit (60 molecules).
Background and aims: Priority setting is a challenging task for public health professionals. To support health professionals with this and in following a recommendation from the Food and Agriculture Organization of the United Nations (FAO) and World Health Organization (WHO), 35 European parasitologists attended a workshop from 8–12 February 2016 to rank food-borne parasites (FBP) in terms of their importance for Europe and regions within Europe. Methods: Countries were divided into European regions according to those used by the European Society of Clinical Microbiology and Infectious Diseases. We used the same multicriteria decision analysis approach as the FAO/WHO, for comparison of results, and a modified version, for better regional representation. Twenty-five FBP were scored in subgroups, using predefined decision rules. Results: At the European level, Echinococcus multilocularis ranked first, followed by Toxoplasma gondii and Trichinella spiralis. At the regional level, E. multilocularis ranked highest in Northern and Eastern Europe, E. granulosus in South-Western and South-Eastern Europe, and T. gondii in Western Europe. Anisakidae, ranking 17th globally, appeared in each European region’s top 10. In contrast, Taenia solium, ranked highest globally but 10th for Europe. Conclusions: FBP of importance in Europe differ from those of importance globally, requiring targeted surveillance systems, intervention measures, and preparedness planning that differ across the world and across Europe.
Motivation: The progress of High Throughput Sequencing (HTS) technologies and the reduction in the sequencing costs are such that Whole Genome Sequencing (WGS) could replace many traditional laboratory assays and procedures. Exploiting the volume of data produced by HTS platforms requires substantial computing skills and this is the main bottleneck in the implementation of WGS as a routine laboratory technique. The way in which the vast amount of results are presented to researchers and clinicians with no specialist knowledge of genome sequencing is also a significant issue. Results: Here we present TORMES, a user-friendly pipeline for WGS analysis of bacteria from any origin generated by HTS on Illumina platforms. TORMES is designed for non-bioinformatician users, and automates the steps required for WGS analysis directly from the raw sequence data: sequence quality filtering, de novo assembly, draft genome ordering against a reference, genome annotation, multi-locus sequence typing (MLST), searching for antibiotic resistance and virulence genes, and pangenome comparisons. Once the analysis is finished, TORMES generates and interactive web-like report that can be opened in any web browser and shared and revised by researchers in a simple manner. TORMES can be run by using very simple commands and represent a quick an easy way to perform WGS analysis. Availability and implementation: TORMES is free available at https://github.com/nmquijada/tormes. Supplementary information: Supplementary data are available at Bioinformatics online.
We evaluated the prevalence of hepatitis E virus (HEV) in the pork production chain in Czech Republic, Italy, and Spain during 2010. A total of 337 fecal, liver, and meat samples from animals at slaughterhouses were tested for HEV by real-time quantitative PCR. Overall, HEV was higher in Italy (53%) and Spain (39%) than in Czech Republic (7.5%). HEV was detected most frequently in feces in Italy (41%) and Spain (39%) and in liver (5%) and meat (2.5%) in Czech Republic. Of 313 sausages sampled at processing and point of sale, HEV was detected only in Spain (6%). HEV sequencing confirmed only g3 HEV strains. Indicator virus (porcine adenovirus) was ubiquitous in fecal samples and absent in liver samples and was detected in 1 slaughterhouse meat sample. At point of sale, we found porcine adenovirus in sausages (1%–2%). The possible dissemination of HEV and other fecal viruses through pork production demands containment measures.
1 June 2007 in Trends in Food Science & Technology