Functional maturation and longitudinal imaging of intraportal neonatal porcine islet grafts in genetically diabetic pigs.

Allogeneic intraportal islet transplantation (ITx) has become an established treatment for patients with poorly controlled type 1 diabetes. However, the loss of viable beta-cell mass after transplantation remains a major challenge. Therefore, noninvasive imaging methods for long-term monitoring of the transplant fate are required. In this study, [68Ga]Ga-DOTA-exendin-4 positron emission tomography/computed tomography (PET/CT) was used for repeated monitoring of allogeneic neonatal porcine islets (NPI) after intraportal transplantation into immunosuppressed genetically diabetic pigs. NPI transplantation (3320-15,000 islet equivalents per kg body weight) led to a reduced need for exogenous insulin therapy and finally normalization of blood glucose levels in 3 out of 4 animals after 5 to 10 weeks. Longitudinal PET/CT measurements revealed a significant increase in standard uptake values in graft-bearing livers. Histologic analysis confirmed the presence of well-engrafted, mature islet clusters in the transplanted livers. Our study presents a novel large animal model for allogeneic intraportal ITx. A relatively small dose of NPIs was sufficient to normalize blood glucose levels in a clinically relevant diabetic pig model. [68Ga]Ga-DOTA-exendin-4 PET/CT proved to be efficacious for longitudinal monitoring of islet transplants. Thus, it could play a crucial role in optimizing ITx as a curative therapy for type 1 diabetes.

High incidence of cold-tolerant Clostridium frigoriphilum and C. algidicarnis in vacuum-packed beef on retail sale in Germany.

Sixty vacuum-packed beef samples retailed in Germany were investigated for the occurrence of cold-tolerant Clostridium spp. After a storage period at 4 °C for eight weeks, meat juice from all samples was processed for culturing, DNA extraction and SYBR green qPCR for Clostridium species. After that, a previously developed multiplex qPCR, sequence analysis of the 16S rRNA gene, and MALDI-TOF MS were applied in order to identify Clostridium spp. found in samples. Subsequently, 23 samples were found positive for C. frigoriphilum (n = 19), C. estertheticum (n = 2), C. tagluense (n = 1) and C. lacusfryxellense/C. frigoris (n = 1). By using a new multiplex qPCR and a new RFLP method developed in this study, a further 15 meat juice samples were revealed to be contaminated with C. algidicarnis. With some samples being co-contaminated with two different species, 53% (n = 32) of all investigated vacuum-packed beef samples were found to be positive for cold-tolerant clostridia. This is the first report of detection and identification of C. algidicarnis in meat samples in Germany and Central Europe.