Validation of the AtlasTMCampylobacter Detection Assay: AOAC Performance Tested MethodSM 032101.

BACKGROUND: Campylobacter spp. are a major causal agent for diarrheal illness in humans. Detection of Campylobacter spp. in food is critical to reduce foodborne illness, and to provide safe foods. OBJECTIVE: The aim was to evaluate the Atlas Campylobacter Detection Assay for AOAC Performance Tested MethodsSM certification for detecting C. jejuni, C. coli, and C. lari in foods after 12 h enrichment. METHOD: The Atlas Campylobacter Detection Assay was compared to the ISO 10272-1:2017 reference culture method for chicken carcass rinse, turkey carcass sponge, raw ground poultry, raw ground pork, and ready-to-eat (RTE) meats. Inclusivity, exclusivity, product consistency, product stability, and robustness studies were also performed. An independent laboratory evaluated the performance of the Atlas Campylobacter Detection Assay method on chicken carcass rinse. RESULTS: No significant differences were observed between the Atlas Campylobacter Detection Assay and the reference ISO method in spiked food matrixes. The Atlas Campylobacter Detection Assay detected all 50 inclusive organisms and none of the 30 exclusive organisms. Product consistency and stability studies showed no statistical differences between lots or over the term of the shelf-life using accelerated method study. Finally, the robustness study showed no statistical difference between different sample volumes, enrichment times, and storage time after sample transfer. CONCLUSIONS: The results of this study indicate that the Atlas Campylobacter Detection Assay is comparable to ISO 10272-1:2017 for detecting Campylobacter in chicken carcass rinse, turkey carcass sponge, raw ground poultry, raw ground pork, and RTE meats. HIGHLIGHTS: The Atlas Campylobacter Detection Assay is a rapid, accurate molecular method able to detect C. jejuni, C. coli, and C. lari in in chicken carcass rinse, turkey carcass sponge, raw ground poultry, raw ground pork, and RTE meats within 12-18 h.

The polyembryo gene (OsPE) in rice.

T-DNA insertional mutagenesis is one of the most important approaches for gene discovery and cloning. A fertile polyembryo mutant generated by T-DNA/Ds insertion in Oryza sativa, cv. Basmati 370 showed twin or triple seedlings at a frequency of 15-20%. T-DNA insertion was confirmed by 950 bp hpt gene amplification in the promoter region of the candidate gene. The annotated protein corresponding to the OsPE candidate gene has been reported as a hypothetical protein in O. sativa. OsPE gene lacked functional homologs in other species. No OsPE paralog was found in rice. No conserved domains were found in the protein coded by OsPE. RT-PCR showed the expression of OsPE gene in Basmati 370 shoots. Full-length OsPE gene was cloned in Basmati 370. The combined use of Southern blot, genome walking, TAIL-PCR, RT-PCR techniques, and bioinformatics led to the identification of a candidate gene controlling the multiple embryos in rice. There is gain of function, i.e., multiple embryos in the seeds in the knockout mutant OsPE whereas its wild-type allele strictly controls single embryo per seed. The seeds with multiple embryos are distributed at random in the rice mutant panicle. The origin of multiple embryos, whether apomictic, zygotic or both is under investigation.

Rapid Detection and Classification of Salmonella enterica Shedding in Feedlot Cattle Utilizing the Roka Bioscience Atlas Salmonella Detection Assay for the Analysis of Rectoanal Mucosal Swabs.

With an increasing focus on preharvest food safety, rapid methods are required for the detection and quantification of foodborne pathogens such as Salmonella enterica in beef cattle. We validated the Atlas Salmonella Detection Assay (SEN), a nucleic acid amplification technology that targets Salmonella rRNA, for the qualitative detection of S. enterica with sample enrichment using immunomagnetic separation as a reference test, and we further evaluated its accuracy to predict pathogen load using SEN signal-to-cutoff (SCO) values from unenriched samples to classify animals as high or nonhigh shedders. Rectoanal mucosal swabs (RAMS) were collected from 238 beef cattle from five cohorts located in the Midwest or southern High Plains of the United States between July 2015 and April 2016. Unenriched RAMS samples were used for the enumeration and SEN SCO analyses. Enriched samples were tested using SEN and immunomagnetic separation methods for the detection of Salmonella. The SEN method was 100% sensitive and specific for the detection of Salmonella from the enriched RAMS samples. A SEN SCO value of 8, with a sensitivity of 93.5% and specificity of 94.3%, was found to be an optimum cutoff value for classifying animals as high or nonhigh shedders from the unenriched RAMS samples. The SEN assay is a rapid and reliable method for the qualitative detection and categorization of the shedding load of Salmonella from RAMS in feedlot cattle.