Three-dimensional modelling as a novel interactive tool for preoperative planning for complex perianal fistulas in Crohn's disease

Crohn disease; Artificial intelligence; Three-dimensional imagingEnfermedad de Crohn; Inteligencia artificial; Imagen tridimensionalMalaltia de Crohn; Intel·ligència artificial; Imatge tridimensionalAim The aim of this study is to demonstrate the added value of three-dimensional (3D) reconstruction models and artificial intelligence for preoperative planning in complex perianal Crohn's disease. MRI is the gold standard for diagnosis of complex perianal fistulas and abscess due to its high sensitivity, but it lacks high specificity values. This creates the need for better diagnostic models such as 3D image processing and reconstruction (3D-IPR) with artificial intelligence (AI) algorithms. Method This is a prospective study evaluating the utility of 3D reconstruction models from MRI in four patients with perineal Crohn's disease (pCD). Results Four pCD patients had 3D reconstruction models made from pelvic MRI. This provided a more visual representation of perianal disease and made possible location of the internal fistula orifice, seton placement in fistula tracts and abscess drainage. Conclusion Three-dimensional reconstruction in CD-associated complex perianal fistulas can facilitate disease interpretation, anatomy and surgical strategy, potentially improving preoperative planning as well as intraoperative assistance. This could probably result in better surgical outcomes to control perianal sepsis and reduce the number of surgical procedures required in these patients

Red LED Light Acts on the Mitochondrial Electron Chain of Mammalian Sperm via Light-Time Exposure-Dependent Mechanisms

This work analyzes the effects of red LED light on mammalian sperm mitochondrial function, using the pig as an animal model. Liquid-stored pig semen was stimulated with red-light for 1, 5 and 10 min in the presence or absence of oligomycin A, a specific inhibitor of mitochondrial ATP synthase, or carbonyl cyanide 4-(trifluoromethoxy)phenylhydrazone (FCCP), a specific disruptor of mitochondrial electron chain. Whereas exposure for 1 and 5 min significantly (p < 0.05) decreased total motility and intracellular ATP levels, irradiation for 10 min induced the opposite effect. Oligomycin A abolished the light-effects on intracellular ATP levels, O2 consumption and mitochondrial membrane potential, whereas compared to non-irradiated samples, FCCP significantly (p < 0.05) increased O2 consumption when sperm were irradiated for 1 min. Both oligomycin A and FCCP significantly (p < 0.05) decreased total motility. Red-light increased cytochrome c oxidase activity with a maximal effect after 5 min of irradiation, which was abolished by both oligomycin A and FCCP. In conclusion, red-light modulates sperm mitochondrial function via electron chain activity in an exposition, time-dependent manner

Leer en comunidad: Creación y desarrollo de clubes de lectura dentro y fuera de la Universidad

Depto. de Lengua Española y Teoría de la LiteraturaFac. de FilologíaFALSEsubmitte

A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

Meeting abstrac

Staphylococcus aureus ftnA 3'-untranslated region modulates ferritin production facilitating growth under iron starvation conditions

Iron acquisition and modulation of its intracellular concentration are critical for the development of all living organisms. So far, several proteins have been described to be involved in iron homeostasis. Among them, ferritins act as the major iron storage proteins, sequestering internalized iron and modulating its concentration inside bacterial cells. We previously described that the deletion of the 3’-untranslated region (3’UTR) of the ftnA gene, which codes for ferritin in Staphylococcus aureus, increased the ftnA mRNA and ferritin levels. Here, we show that the ferritin levels are affected by RNase III and PNPase, which target the ftnA 3’UTR. Rifampicin mRNA stability experiments revealed that the half-life of the ftnA mRNA is affected by both RNase III and the ftnA 3’UTR. A transcriptional fusion of the ftnA 3’UTR to the gfp reporter gene decreased green fluorescent protein (GFP) expression, indicating that the ftnA 3’UTR could work as an independent module. Additionally, a chromosomal deletion of the ftnA 3’UTR impaired S. aureus growth under conditions of iron starvation. Overall, this work highlights the biological relevance of the ftnA 3’UTR for iron homeostasis in S. aureus.The authors acknowledge support of the publication fee by the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI)

RNA thermoswitches modulate Staphylococcus aureus adaptation to ambient temperatures

Thermoregulation of virulence genes in bacterial pathogens is essential for environment-to-host transition. However, the mechanisms governing cold adaptation when outside the host remain poorly understood. Here, we found that the production of cold shock proteins CspB and CspC from Staphylococcus aureus is controlled by two paralogous RNA thermoswitches. Through in silico prediction, enzymatic probing and site-directed mutagenesis, we demonstrated that cspB and cspC 5′UTRs adopt alternative RNA structures that shift from one another upon temperature shifts. The open (O) conformation that facilitates mRNA translation is favoured at ambient temperatures (22°C). Conversely, the alternative locked (L) conformation, where the ribosome binding site (RBS) is sequestered in a double-stranded RNA structure, is folded at host-related temperatures (37°C). These structural rearrangements depend on a long RNA hairpin found in the O conformation that sequesters the anti-RBS sequence. Notably, the remaining S. aureus CSP, CspA, may interact with a UUUGUUU motif located in the loop of this long hairpin and favour the folding of the L conformation. This folding represses CspB and CspC production at 37°C. Simultaneous deletion of the cspB/cspC genes or their RNA thermoswitches significantly decreases S. aureus growth rate at ambient temperatures, highlighting the importance of CspB/CspC thermoregulation when S. aureus transitions from the host to the environment.A.T.-A. was supported by the European Research Council under the European Union's Horizon 2020 research and innovation program [ERC-CoG-2014-646869]; and the Spanish Ministry of Science and Innovation [PID2019-105216GB-I00] grants. I.C. was supported by Centre National de la Recherche Scientifique (CNRS) through an International Project of Scientific Cooperation between CNRS and CSIC [PICS07507]; and by the framework of the labEx Net RNA, French National Research Agency [ANR-10-LABX-0036 and IMCBio ANR-17-EURE-0023]. Funding for open access charge: CSIC Open Access Publication Support Initiative, Unit of Information Resources for Research (URICI)

La adaptación de Staphylococcus aureus al medio ambiente esta mediada por termosensores de RNA

Resumen del trabajo presentado en el XXVIII Congreso Nacional de la Sociedad Española de Microbiología, celebrado de forma virtual del 28 de junio al 2 de julio de 2021Staphylococcus aureus es uno de los patógenos más importante en los hospitales. Puede producir infecciones graves y resistir a la mayoría de los antibióticos. Además, reside de manera asintomática en el 20-30% de la población, desde donde es capaz de contaminar diversos fómites y diseminarse a otros individuos. Su capacidad para sobrevivir en el ambiente favorece estas reinfecciones, acrecentando el riesgo para la salud pública cuando se trata de cepas multiresistentes. Los mecanismos necesarios para la adaptación de la bacteria cuando escapa del hospedador al ambiente son prácticamente desconocidos. En este estudio, descubrimos dos termosensores de RNA parálogos que controlan la producción de dos de las tres proteínas del “cold-shock” (CSPs) de S. aureus, CspB y CspC. Demostramos que las 5’UTR de cspB y cspC son capaces de adoptar estructuras alternativas en función de la temperatura. En el ambiente (22ºC), las 5’UTRs adoptan una estructura que facilita la traducción (conformación-ON), mientras que en el hospedador (37ºC), se forma una estructura alternativa que bloquea la RBS, inhibiendo la traducción (ConformaciónOFF). Esta inhibición requiere de la CSP restante, CspA, que reconoce un motivo rico en uridinas para evitar la formación de la conformación-ON, liberar la secuencia anti-RBS y formar de manera estable la conformación-OFF. Mutaciones dirigidas que bloquean ambas 5’UTRs en conformaciónOFF impiden el crecimiento de S. aureus a temperatura ambiente. Este estudio pone en evidencia la importancia de la termorregulación mediada por RNAs para la supervivencia de S. aureus fuera de su hospedador, lo que puede contribuir a su transmisión.ERC Consolidator Grant (European Research Council), Ref. ERC-CoG-2014-646869 Agencia Estatal de Investigación, Ministerio de Ciencia e Innovación, Ref PID2019-105216GB-I0

Staphylococcus aureus senses and adapts to ambient temperatures through RNA thermoswitches

Resumen del trabajo presentado en el World Microbe Forum. ASM-FEMS Congress, celebrado online del 20 al 24 de junio de 2021Adaptation to the ever-changing environmental conditions and survival outside the host is crucial for dissemination and transmission of pathogenic bacteria. Staphylococcus aureus may be spread from human carriers to diverse environments and survive outside the host for long periods of time. This capacity has been linked to reinfections in addition to new host colonisations. One of the main variables that bacteria need to face when leaving the host is a shift in temperature. However, the mechanisms governing cold adaptation during this transition remain poorly understood. In this study, we found that two paralogous RNA-thermoswitches controlled the production of cold-shock proteins CspB and CspC in S. aureus. We demonstrated that the cspB and cspC 5’UTRs adopt alternative RNA structures that shift from one another upon temperature changes. These RNA structures resembled the thermo-responsive elements recently described in E. coli and L. monocytogenes. One of the conformations facilitated mRNA translation at ambient temperatures (22ºC) while the other folded into a double stranded RNA structure at host-related temperatures (37ºC) that blocked the ribosome binding site (RBS). We found that the structural rearrangements depended on a long RNA hairpin that sequestered the anti-RBS sequence depending on the environmental temperature. At the same time, the remaining S. aureus CSP, CspA, recognised a UUUGUUU motif located in this long hairpin. Such interaction favoured the release of the anti-RBS sequence and, as a result, repressed the CspB and CspC production at 37ºC. In addition, when both RNA-thermoswitches were simultaneously deleted, S. aureus growth was inhibited at ambient temperatures. All in all, our [ndings highlight the importance of CspB/CspC thermoregulation when S. aureus transitions from the host to the environment

RNA thermoswitches modulate Staphylococcus aureus adaptation to ambient temperatures

Trabajo presentado en la XIII Reunión del Grupo de Microbiología Molecular de la SEM, celebrada en Granada (España), del 7 al 9 de septiembre de 202