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The parasitic roundworm Trichinella spiralis is most commonly transmitted to humans through consumption of raw or undercooked meat of infected pigs or game. To prevent human infection, slaughterhouses perform meat safety surveillance using the gold standard "Magnetic Stirrer Method". We introduce a fast and objective method using automated detection of specific Trichinella spiralis antigens by a newly developed immunoassay based on chemiluminescence (ChLIA). Panel A comprised muscle tissue samples from non-infected pigs (n = 37). Panel B comprised muscle tissue samples from non-infected pigs spiked with different amounts of Trichinella larvae without collagen capsules (n = 56). Panel C contained muscle tissue samples from experimentally infected pigs including Trichinella larvae encapsulated in collagen (n = 32). Each sample was shredded with PBS buffer in a knife mill, destroying Trichinella larvae. Following centrifugation, the supernatant (muscle tissue extract containing released excretory and secretory Trichinella spiralis antigens) was used for Trichinella- specific antigen detection by the new Trichinella ChLIA. The overall accuracy of the Trichinella ChLIA was 97.6 %. The specificity of the Trichinella ChLIA was 100 % (panel A). The sensitivity in samples from experimentally infected pigs was 100 % representing a detection limit of 0.01 larvae per gram. Cross-reactivity with parasites other than Trichinella spp . was not observed. This new meat inspection method for the detection of Trichinella spiralis antigens presents high specificity and high sensitivity, especially in truly infected samples. In contrast to the gold standard, this new approach to meat safety surveillance does not require longsome digestion or microscopy by trained personnel., (© 2020 The Author(s).)

The parasitic roundworm Trichinella spiralis is most commonly transmitted to humans through consumption of raw or undercooked meat of infected pigs or game. To prevent human infection, slaughterhouses perform meat safety surveillance using the gold standard "Magnetic Stirrer Method". We introduce a fast and objective method using automated detection of specific Trichinella spiralis antigens by a newly developed immunoassay based on chemiluminescence (ChLIA). Panel A comprised muscle tissue samples from non-infected pigs (n=37). Panel B comprised muscle tissue samples from non-infected pigs spiked with different amounts of Trichinella larvae without collagen capsules (n=56). Panel C contained muscle tissue samples from experimentally infected pigs including Trichinella larvae encapsulated in collagen (n=32). Each sample was shredded with PBS buffer in a knife mill, destroying Trichinella larvae. Following centrifugation, the supernatant (muscle tissue extract containing released excretory and secretory Trichinella spiralis antigens) was used for Trichinella-specific antigen detection by the new Trichinella ChLIA. The overall accuracy of the Trichinella ChLIA was 97.6 %. The specificity of the Trichinella ChLIA was 100 % (panel A). The sensitivity in samples from experimentally infected pigs was 100 % representing a detection limit of 0.01 larvae per gram. Cross-reactivity with parasites other than Trichinella spp. was not observed. This new meat inspection method for the detection of Trichinella spiralis antigens presents high specificity and high sensitivity, especially in truly infected samples. In contrast to the gold standard, this new approach to meat safety surveillance does not require longsome digestion or microscopy by trained personnel., (Copyright © 2020 The Author(s). Published by Elsevier B.V. All rights reserved.)

In our previous phase 1/2 study aimed at controlling graft-versus-host disease, 12 patients received Herpes simplex virus thymidine kinase (HSV-tk(+))/neomycin phosphotransferase (NeoR(+))-expressing donor gene-modified T cells (GMCs) and underwent an HLA-identical sibling T-cell-depleted bone marrow transplantation (BMT). This study's objective was to follow up, to quantify, and to characterize persistently circulating GMCs more than 10 years after BMT. Circulating GMCs remain detectable in all 4 evaluable patients. However, NeoR- and HSV-tk-polymerase chain reaction (PCR) differently quantified in vivo counts, suggesting deletions within the HSV-tk gene. Further experiments, including a novel "transgene walking" PCR method, confirmed the presence of deletions. The deletions were unique, patient-specific, present in most circulating GMCs expressing NeoR, and shown to occur at time of GMC production. Unique patient-specific retroviral insertion sites (ISs) were found in all GMCs capable of in vitro expansion/cloning as well. These findings suggest a rare initial gene deletion event and an in vivo survival advantage of rare GMC clones resulting from an anti-HSV-tk immune response and/or ganciclovir treatment. In conclusion, we show that donor mature T cells infused with a T-cell-depleted graft persist in vivo for more than a decade. These cells, containing transgene deletions and subjected to significant in vivo selection, represent a small fraction of T cells infused at transplantation.