A critical review of current progress in 3D kidney biomanufacturing: advances, challenges, and recommendations

The widening gap between organ availability and need is resulting in a worldwide crisis, particularly concerning kidney transplantation. Regenerative medicine options are becoming increasingly advanced and are taking advantage of progress in novel manufacturing techniques, including 3D bioprinting, to deliver potentially viable alternatives. Cell-integrated and wearable artificial kidneys aim to create convenient and efficient systems of filtration and restore elements of immunoregulatory function. Whilst preliminary clinical trials demonstrated promise, manufacturing and trial design issues and identification of suitable and sustainable cell sources have shown that more development is required for market progression. Tissue engineering and advances in biomanufacturing techniques offer potential solutions for organ shortages; however, due to the complex kidney structure, previous attempts have fallen short. With the recent development and progression of 3D bioprinting, cell positioning and resolution of material deposition in organ manufacture have never seen greater control. Cell sources for constructing kidney building blocks and populating both biologic and artificial scaffolds and matrices have been identified, but in vitro culturing and/or differentiation, in addition to maintaining phenotype and viability during and after lengthy and immature manufacturing processes, presents additional problems. For all techniques, significant process barriers, clinical pathway identification for translation of models to humans, scaffold material availability, and long-term biocompatibility need to be addressed prior to clinical realisation

The Molecular Epidemiology of Resistance in Cefotaximase-Producing Escherichia coli Clinical Isolates from Dublin, Ireland.

In view of continued high clinical prevalence of infections involving extended-spectrum β-lactamase (ESBL)-producing Escherichia coli, this study sought to characterise the blaCTX-M genes, their associated mobile genetic elements and the integrons present in 100 ESBL-producing E. coli isolates collected in a Dublin hospital and associated community healthcare facilities. Polymerase chain reaction (PCR) mapping and sequencing was used to detect blaCTX-M alleles, their associated insertion sequences (ISs) and class 1 and 2 integrons in the collection. ESBL plasmids were characterised by PCR-based replicon typing and replicon sequence typing (RST). Cefotaximases were harboured by 94% of isolates (66 blaCTX-M-15, 8 blaCTX-M-14, 7 blaCTX-M-1, 4 blaCTX-M-3, 3 blaCTX-M-9, 2 blaCTX-M-27, 2 blaCTX-M-55, 1 blaCTX-M-32 and 1 blaCTX-M-2). An ISEcp1 promoter was linked to a group 1 blaCTX-M gene in 45% of isolates. A further 34% of isolates contained blaCTX-M-15 downstream of IS26, an arrangement typical of epidemic UK strain A. Class 1 integrons were found in 66% of isolates, most carrying trimethoprim/aminoglycoside resistance genes. CTX-M plasmids were primarily of multireplicon IncF or IncI1 type, but IncN and unidentified types were also found. Novel IncF RSTs F1:A-:B-, F45:A1:B-, F45:A4:B- and a novel IncI1 sequence type, ST159, were identified. CTX-M plasmids and integrons resembled those identified recently in animal isolates from Ireland and Western Europe. The molecular epidemiology of CTX-M-producing E. coli in Dublin suggests that horizontal spread of mobile genetic elements contributes to antimicrobial resistant human infections. Further investigations into whether animals or animal products represent an important local reservoir for these elements are warranted.</p