An international inter-laboratory study to compare digital PCR with ISO standardized qPCR assays for the detection of norovirus GI and GII in oyster tissue.

An optimized digital RT-PCR (RT-dPCR) assay for the detection of human norovirus GI and GII RNA was compared with ISO 15216-conform quantitative real-time RT-PCR (RT-qPCR) assays in an interlaboratory study (ILS) among eight laboratories. A duplex GI/GII RT-dPCR assay, based on the ISO 15216-oligonucleotides, was used on a Bio-Rad QX200 platform by six laboratories. Adapted assays for Qiagen Qiacuity or ThermoFisher QuantStudio 3D were used by one laboratory each.

Quantitative levels of norovirus and hepatitis A virus in bivalve molluscs collected along the food chain in the Netherlands, 2013-2017.

Contamination of bivalve molluscs with viruses is well recognized as a food safety risk. A microbiological criterion for norovirus (NoV) and hepatitis A virus (HAV) in shellfish, however, does not exist in the European Union currently. The aim of this study was to evaluate the contamination levels of these viruses for fluctuation over a long period (2013-2017) in oyster (n = 266) and mussel samples (n = 490) using a method based on ISO/TS 15216-1: 2013.

Monitoring of pork liver and meat products on the Dutch market for the presence of HEV RNA.

The aim of the present study was to assess pork liver and meat products present on the Dutch market for the presence of hepatitis E virus (HEV) RNA. HEV RNA was detected in 27.3% of 521 products sampled from Dutch retail stores in 2016.

Rapid detection and differentiation of Salmonella species, Salmonella Typhimurium and Salmonella Enteritidis by multiplex quantitative PCR.

A multiplex quantitative PCR (qPCR) was developed and evaluated for the simultaneous detection of Salmonella spp., S. enterica serovar Typhimurium and S.

Porcine blood used as ingredient in meat productions may serve as a vehicle for hepatitis E virus transmission.

The aim of the present study was to investigate whether the use of porcine blood(products) in food could be a risk for a hepatitis E virus (HEV) infection. HEV RNA was detected in 33/36 batches of (non-heated) liquid products and in 7/24 spray dried powder products. Contamination levels varied among the products, but were highest in liquid whole blood, plasma and fibrinogen reaching levels of 2.

The influence of preoperative serum anticholinergic activity and other risk factors for the development of postoperative cognitive dysfunction after cardiac surgery.

Objective: Patients undergoing cardiac surgery are at risk for postoperative cognitive dysfunction (POCD). Evaluating preoperative risk factors represents 1 possible way to minimize the postoperative risk of cognitive dysfunction. We investigated marked deterioration in cholinergic neurotransmission as 1 such potential risk factor for transient and long-lasting POCD.

Comparison of auditory deficits associated with neglect and auditory cortex lesions.

In contrast to lesions of the visual and somatosensory cortex, lesions of the auditory cortex are not associated with self-evident contralesional deficits. Only when two or more stimuli are presented simultaneously to the left and right, contralesional extinction has been observed after unilateral lesions of the auditory cortex. Because auditory extinction is also considered a sign of neglect, clinical separation of auditory neglect from deficits caused by lesions of the auditory cortex is challenging.

Surveillance study of hepatitis A virus RNA on fig and date samples.

A total of 91 fig and 185 date samples were analyzed by reverse transcription (RT) real-time PCR for the presence of hepatitis A virus (HAV) RNA. Two batches of dates tested positive, and the HAV RNA detected was genotyped as IA. These findings warrant further development of methods applicable to food which is consumed untreated and is exported from countries in which HAV is endemic.

Development and inter-laboratory evaluation of real-time PCR assays for the detection of pospiviroids.

Assays based on real-time PCR (TaqMan) that can detect a number of viroids in the genus Pospiviroid have been developed and evaluated. The assays are designed for detecting viroids from tomato leaf material but detection from other solanaceous hosts of these viroids has been confirmed. These methods have been validated by nine laboratories and comprise a reliable set of assays for the detection of CEVd, TASVd, CLVd and a generic assay which will detect the six viroids of concern to European tomato growers: PSTVd, TCDVd, CEVd, CLVd, TASVd and CSVd.