Project description:The Blood Borne Pathogen Resequencing Microarray Expanded (BBP-RMAv.2) is a platform that allows multiplex detection and identification of 80 different blood-borne pathogens in one single test, comprising 60 virus, 5 bacteria and 15 parasites. The objective is to evaluate the lowest concentration detected in blood or plasma, species discrimination and applicability of the microarray platform for testing blood donors. Human blood or plasma spiked with selected pathogens (10,000, 1,000 or 100 cells or copies/ml), including 6 viral, 2 bacterial and 5 protozoan pathogens were each tested on this platform. The nucleic acids were extracted, amplified using multiplexed sets of pooled specific primers, fragmented, labeled, and hybridized to a microarray. Finally, the detected sequences were identified using an automated genomic database alignment algorithm. The performance of the BBP-RMAv.2 demonstrated detection for most spiked protozoan pathogens at 1,000 cells/ml, 10,000 cells/ml for bacterial pathogens and as low as 100 copies/ml for viral pathogens. Coded specimens, including spiked and negative controls, were identified correctly for one blood specimen and for two plasma specimens. One negative plasma resulted in a false positive detection of a virus demonstrating the effectiveness of the platform.
Project description:Enterotoxin-producing C. perfringens type A is a common cause of food poisonings. The cpe encoding the enterotoxin can be chromosomal (genotype IS1470) or plasmid-borne (genotypes IS1470-like-cpe or IS1151-cpe). The chromosomal cpe-carrying C. perfringens are a more common cause of food poisonings than plasmid-borne cpe-genotypes. The chromosomal cpe-carrying C. perfringens type A strains are generally more resistant to most food-processing conditions than plasmid-borne cpe-carrying strains. On the other hand, the plasmid-borne cpe-positive genotypes are more commonly found in human feces than chromosomal cpe-positive genotypes, and humans seem to be a reservoir for plasmid-borne cpe-carrying strains. Thus, it is possible that the epidemiology of C. perfringes type A food poisonings caused by plasmid-borne and chromosomal cpe-carrying strains is different. A DNA microarray was designed for analysis of genetic relatedness between the different cpe-positive and cpe-negative genotypes of C. perfringens strains isolated from human, animal, environmental and food samples. The DNA microarray contained two probes for all protein-coding sequences in the three genome-sequenced strains (C. perfringens type A strains 13, ATCC13124, and SM101). The chromosomal and plasmid-borne C. perfringens genotypes were grouped into two distinct clusters, one consisting of the chromosomal cpe-genotypes and the other consisting of plasmid-borne cpe-genotypes. Analysis of the variable gene pool complemented with the growth studies demonstrate different carbohydrate and amine metabolism in the chromosomal and plasmid-borne cpe-carrying strains, suggesting different epidemiology of the cpe-positive C. perfringens strain groups.
2012-03-01 | GSE30954 | GEO
Project description:Molecular detection of vector-borne pathogens from naturally infected dogs
Project description:Early detection of spoilage microorganisms and food pathogens is of major importance in preventing food recalls and foodborne outbreaks. Although constant effort is invested in developing sensitive methods for rapid microbial detection, none of the current methods enables the detection of food pathogens within a few hours; therefore, development of innovative early-warning food-testing strategies are needed. Herein, we assessed a novel strategy that harnesses the microbiome signature of a food product to determine deviations in the abundance of particular community members and detect production defects. Employing the production process of barbecued (BarBQ) pastrami as a model, we characterized the microbiome profiles of the product along the production line using next-generation sequencing of the 16S rRNA gene, concentrating on the live microbiota. Following the establishment of a microbiome dataset representing a properly produced product, we were able to identify shifts in the microbiome profile of a defective batch produced under potassium lactate deficiency. With the identification of Vibrio and Lactobacillus as potential indicator bacteria for potassium lactate deficiency, rapid qPCR assays were designed for their quantification. Aligned with the microbiome profiling results, these qPCR assays were effective for rapid identification of a defective production event. This implies the use of rapid quantification targeting microbiome profile-derived indicator bacteria for in-house detection of defective batches and identification of food-safety and quality events with results obtained on the same day. The suggested strategy should pave the way toward safer and more efficient food-production systems.
2024-08-27 | GSE255249 | GEO
Project description:Food-borne bacteria
| PRJNA946912 | ENA
Project description:Food-borne pathogen
| PRJNA1030778 | ENA
Project description:Nanopore adaptive sampling for metagenomic detection of human tick-borne pathogens
Project description:Enterotoxin-producing C. perfringens type A is a common cause of food poisonings. The cpe encoding the enterotoxin can be chromosomal (genotype IS1470) or plasmid-borne (genotypes IS1470-like-cpe or IS1151-cpe). The chromosomal cpe-carrying C. perfringens are a more common cause of food poisonings than plasmid-borne cpe-genotypes. The chromosomal cpe-carrying C. perfringens type A strains are generally more resistant to most food-processing conditions than plasmid-borne cpe-carrying strains. On the other hand, the plasmid-borne cpe-positive genotypes are more commonly found in human feces than chromosomal cpe-positive genotypes, and humans seem to be a reservoir for plasmid-borne cpe-carrying strains. Thus, it is possible that the epidemiology of C. perfringes type A food poisonings caused by plasmid-borne and chromosomal cpe-carrying strains is different. A DNA microarray was designed for analysis of genetic relatedness between the different cpe-positive and cpe-negative genotypes of C. perfringens strains isolated from human, animal, environmental and food samples. The DNA microarray contained two probes for all protein-coding sequences in the three genome-sequenced strains (C. perfringens type A strains 13, ATCC13124, and SM101). The chromosomal and plasmid-borne C. perfringens genotypes were grouped into two distinct clusters, one consisting of the chromosomal cpe-genotypes and the other consisting of plasmid-borne cpe-genotypes. Analysis of the variable gene pool complemented with the growth studies demonstrate different carbohydrate and amine metabolism in the chromosomal and plasmid-borne cpe-carrying strains, suggesting different epidemiology of the cpe-positive C. perfringens strain groups. Array CGH. Two-color hybridizations on 8x15K Agilent arrays. Eight reference strain hybridizations. Normalization was based on log-ratios against the reference strain. For each sample, 8 normalization factors were calculated, one against each reference hybridization, and the median normalization factor was used. This was repeated for each sample hybridization separately.