Temporal dynamics of SARS-CoV-2 shedding in feces and saliva: a longitudinal study in Norfolk, United Kingdom during the 2021-2022 COVID-19 waves.

Unlabelled: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was originally described as a respiratory illness; however, it is now known that the infection can spread to the gastrointestinal tract, leading to shedding in feces potentially being a source of infection through wastewater. We aimed to assess the prevalence and persistence of SARS-CoV-2 in fecal and saliva samples for up to 7 weeks post-detection in a cohort of 98 participants from Norfolk, United Kingdom using RT-qPCR. Secondary goals included sequencing the viral isolates present in fecal samples and comparing the genetic sequence with isolates in the saliva of the same participant.

Development of a monoclonal antibody sandwich ELISA for the quality control of human and animal tetanus vaccines.

Antigen identity, quantity and integrity are key factors to be evaluated as part of consistency testing of tetanus vaccines. Here we have developed a monoclonal antibody sandwich ELISA to measure the relative amount and quality of tetanus toxoid (TTxd) in human and animal tetanus vaccines. The ELISA is highly specific, has good dilutional linearity, and is suitable for detecting TTxd in a range of different products.

Development of a monoclonal antibody sandwich ELISA for the determination of antigen content and quality in diphtheria vaccines.

At present, quality control of diphtheria vaccines by both manufacturers and national control laboratories relies heavily on in vivo assays to confirm potency. As part of the VAC2VAC project we have developed a monoclonal antibody (mAb) enzyme-linked immunosorbent assay (ELISA) to measure the relative amount and quality of diphtheria toxoid (DTxd) in diphtheria-tetanus based vaccines and believe this test has the potential to play a key role in a control strategy no longer including an in vivo potency test. The mAb ELISA is highly specific, has good dilutional linearity, and is suitable for detecting DTxd in a range of different human vaccine products.

Translocation of outer membrane vesicles from enterohemorrhagic O157 across the intestinal epithelial barrier.

Outer membrane vesicles (OMVs) carrying virulence factors of enterohemorrhagic (EHEC) are assumed to play a role in the pathogenesis of life-threatening hemolytic uremic syndrome (HUS). However, it is unknown if and how OMVs, which are produced in the intestinal lumen, cross the intestinal epithelial barrier (IEB) to reach the renal glomerular endothelium, the major target in HUS. We investigated the ability of EHEC O157 OMVs to translocate across the IEB using a model of polarized Caco-2 cells grown on Transwell inserts and characterized important aspects of this process.

Comparison of Shiga toxin-encoding bacteriophages in highly pathogenic strains of Shiga toxin-producing O157:H7 in the UK.

Over the last 35 years in the UK, the burden of Shiga toxin-producing (STEC) O157:H7 infection has, during different periods of time, been associated with five different sub-lineages (1983-1995, Ia, I/IIa and I/IIb; 1996-2014, Ic; and 2015-2018, IIb). The acquisition of a -encoding bacteriophage by these five sub-lineages appears to have coincided with their respective emergences. The Oxford Nanopore Technologies (ONT) system was used to sequence, characterize and compare the -encoding prophages harboured by each sub-lineage to investigate the integration of this key virulence factor.

A nanobody targeting the translocated intimin receptor inhibits the attachment of enterohemorrhagic E. coli to human colonic mucosa.

Enterohemorrhagic E. coli (EHEC) is a human intestinal pathogen that causes hemorrhagic colitis and hemolytic uremic syndrome. No vaccines or specific therapies are currently available to prevent or treat these infections.