The use of biomimetic surfaces to reduce single- and dual-species biofilms of Escherichia coli and Pseudomonas putida.

The ability of bacteria to adhere to and form biofilms on food contact surfaces poses serious challenges, as these may lead to the cross-contamination of food products. Biomimetic topographic surface modifications have been explored to enhance the antifouling performance of materials. In this study, the topography of two plant leaves, Brassica oleracea var. botrytis (cauliflower, CF) and Brassica oleracea capitate (white cabbage, WC), was replicated through wax moulding, and their antibiofilm potential was tested against single- and dual-species biofilms of Escherichia coli and Pseudomonas putida. Biomimetic surfaces exhibited higher roughness values (SaWC = 4.0 ± 1.0 µm and SaCF = 3.3 ± 1.0 µm) than the flat control (SaF = 0.6 ± 0.2 µm), whilst the CF surface demonstrated a lower interfacial free energy (ΔGiwi) than the WC surface (-100.08 mJ m-2 and -71.98 mJ m-2, respectively). The CF and WC surfaces had similar antibiofilm effects against single-species biofilms, achieving cell reductions of approximately 50% and 60% for E. coli and P. putida, respectively, compared to the control. Additionally, the biomimetic surfaces led to reductions of up to 60% in biovolume, 45% in thickness, and 60% in the surface coverage of single-species biofilms. For dual-species biofilms, only the E. coli strain growing on the WC surface exhibited a significant decrease in the cell count. However, confocal microscopy analysis revealed a 60% reduction in the total biovolume and surface coverage of mixed biofilms developed on both biomimetic surfaces. Furthermore, dual-species biofilms were mainly composed of P. putida, which reduced E. coli growth. Altogether, these results demonstrate that the surface properties of CF and WC biomimetic surfaces have the potential for reducing biofilm formation.

Flagellar interference with plasmid uptake in biofilms: a joint experimental and modeling study.

Plasmid conjugation is a key facilitator of horizontal gene transfer (HGT), and plasmids encoding antibiotic resistance drive the increasing prevalence of antibiotic resistance. In natural, engineered, and clinical environments, bacteria often grow in protective biofilms. Therefore, a better understanding of plasmid transfer in biofilms is needed. Our aim was to investigate plasmid transfer in a biofilm-adapted wrinkly colony mutant of Xanthomonas retroflexus (XRw) with enhanced matrix production and reduced motility. We found that XRw biofilms had an increased uptake of the broad host-range IncP-1ϵ plasmid pKJK5 compared to the wild type (WT). Proteomics revealed fewer flagellar-associated proteins in XRw, suggesting that flagella were responsible for reducing plasmid uptake. This was confirmed by the higher plasmid uptake of non-flagellated fliM mutants of the X. retroflexus wrinkly mutant as well as the wild type. Moreover, testing several flagellar mutants of Pseudomonas putida suggested that the flagellar effect was more general. We identified seven mechanisms with the potential to explain the flagellar effect and simulated them in an individual-based model. Two mechanisms could thus be eliminated (increased distances between cells and increased lag times due to flagella). Another mechanism identified as viable in the modeling was eliminated by further experiments. The possibility of steric hindrance of pilus movement and binding by flagella, reducing the frequency of contact and thus plasmid uptake, proved viable, and the three other viable mechanisms had a reduced probability of plasmid transfer in common. Our findings highlight the important yet complex effects of flagella during bacterial conjugation in biofilms.IMPORTANCEBiofilms are the dominant form of microbial life and bacteria living in biofilms are markedly different from their planktonic counterparts, yet the impact of the biofilm lifestyle on horizontal gene transfer (HGT) is still poorly understood. Horizontal gene transfer by conjugative plasmids is a major driver in bacterial evolution and adaptation, as exemplified by the troubling spread of antibiotic resistance. To either limit or promote plasmid prevalence and dissemination, we need a better understanding of plasmid transfer between bacterial cells, especially in biofilms. Here, we identified a new factor impacting the transfer of plasmids, flagella, which are required for many types of bacterial motility. We show that their absence or altered activity can lead to enhanced plasmid uptake in two bacterial species, Xanthomonas retroflexus and Pseudomonas putida. Moreover, we demonstrate the utility of mathematical modeling to eliminate hypothetical mechanisms.

Draft genomes of seven isolates from Danish wastewater facilities belonging to Pseudomonas, Bacillus, Pseudochrobactrum, Brevundimonas, and Pandoraea.

We report here seven draft genomes of bacterial strains from two Danish wastewater facilities, two of which might be characterized as a new group within the Pseudomonas and Pseudochrobactrum genera, respectively. These genomes will provide useful references for understanding bacterial interactions and horizontal gene transfer within bacterial communities.

High-throughput screening alternative to crystal violet biofilm assay combining fluorescence quantification and imaging.

The crystal violet assay is widely used for biofilm quantitation despite its toxicity and variability. Here, we instead combine fluorescence labelling with the Cytation 5 multi-mode plate reader, to enable simultaneous acquisition of both quantitative and imaging biofilm data. This high-throughput method produces more robust data and provides information about morphology and spatial species organization within the biofilm.

Telómeros, telomerasa y envejecimiento. Una visita al Premio Nobel de Fisiología y Medicina de 2009 / Telomeres, telomerase and aging. A visit to the 2009 Nobel Prize in Physiology and Medicine

Introducción: En octubre de 2009, Elizabeth H. Blackburn, Carol W. Greider y Jack W. Szostak fueron galardonados por sus descubrimientos sobre los telómeros y la enzima telomerasa con el Premio Nobel de Fisiología y Medicina. Posteriormente muchas investigaciones, entre las que destacan la de científicos españoles han demostrado el papel de los telómeros en el envejecimiento y en algunas patologías relacionadas.Métodos: Para la realización de este trabajo se ha revisado tres aspectos: a) la información dada por el Comité del Nobel sobre las investigaciones de los tres galardonados; b) los mecanismos moleculares implicados en el proceso de protección de los telómeros por la acción de la telomerasa y c) la relación entre envejecimiento y sistema telómeros/telomerasa.Resultados: En las células eucariotas los telómeros constituyen el extremo terminal de los cromosomas, los cuales se acortan en cada división celular. Cuando el acortamiento es crítico, se induce daño persistente al ADN en estos extremos, senescencia, apoptosis y pérdidas de la capacidad regenerativa de los tejidos. Dada la imposibilidad de replicación completa de los telómeros por la ADN polimerasa después de cada división celular, la telomerasa, una ribonucloproteína retrotranscriptasa, actúa alargando los extremos de los cromosomas, utilizando como molde una porción de su propio ARN. Muchos factores determinan la longitud de los telómeros, sobresaliendo el acortamiento de los telómeros y la pérdida de actividad telomerásica. Además, existen multitud de factores que condicionan las diferencias entre edad fisiológica y edad cronológica.Conclusión: Entre las muchas teorías sobre el envejecimiento sobresale la que relaciona el acortamiento de los telómeros con la senescencia. No obstante se requieren más estudios en los que se determine qué mecanismos epigenéticos y de otra índole condicionan la pérdida de actividad telomerásica y la longitud de los telómeros.(AU)

Introduction: In October 2009, Elizabeth H. Blackburn, Carol W. Greider, and Jack W. Szostak were awarded the Nobel Prize in Physiology and Medicine for their discoveries about telomeres and the enzyme telomerase. Subsequently, many investigations, including that of Spanish scientists, have demonstrated the role of telomeres in aging and in some very prevalent pathologies.Methods: Three topics were reviewed to perform this article: a) the information given by the Nobel Committee on the research of the three winners of 2009 award; b) the molecular mechanisms involved in the protection process of telomeres by the telomerase enzyme; and c) the relationship between aging and the telomere/telomerase system.Results: In eukaryotic cells, telomeres constitute the terminal end of chromosomes, which are shortened within each cell division. When the shortening becomes critical, persistent DNA damage at these ends, senescence, apoptosis and loss of the tissues regenerative capacity are induced. Given the unfeasibility of telomeres complete replication by the DNA polymerase after each cell division, the telomerase, a reverse transcriptase ribonucloprotein, works by lengthening the ends of chromosomes, using as a template a portion of its own RNA. Several factors determine the length of telomeres and/or the loss of telomerase activity, with aging standing out. In addition, there are many factors that determine the differences between physiological and chronological age.Conclusion: Among aging theories, the one relating the shortening of telomeres with senescence stands out. However, more studies are required to determine which epigenetic and other mechanisms determine the loss of telomerase activity and the length of telomeres.(AU)

Valoración de parámetros clínicos y analíticos preoperatorios en apendicitis aguda complicada. Score para predecir apendicitis complicada / Evaluation of Preoperative Clinical and Serological Determinations in Complicated Acute Appendicitis: A Score for Predicting Complicated Appendicitis

Introducción: Los parámetros clínicos y analíticos de la apendicitis aguda (AA) son la base diagnóstica. Se analiza la diferencia de sus valores según la histología para distinguir las AA simples de las complicadas. Métodos: Análisis observacional retrospectivo que incluye pacientes (>14 años) que ingresan con diagnóstico de AA desde el 1 abril 2014 al 31 julio 2016. Histopatológicamente se dividen en AA complicada (perforada y/o gangrenada) y AA no complicada (flemonosa). Entre los 2 grupos se compara sexo, edad, temperatura al ingreso, duración de sintomatología, recuento leucocitario preoperatorio (WBC), porcentaje de neutrófilos, volumen plaquetario medio (VPM), índice de distribución de plaquetas (PDW), proteína C-reactiva (PCR) y estancia hospitalaria. Resultados: Se analizan 335 pacientes y se incluyen 284, de los cuales 194 (68,3%) tienen AA no complicada (AAnc) y 90 (31,7%) AA complicada (AAc). La edad, la duración de sintomatología, el porcentaje de neutrófilos, la PCR y la estancia hospitalaria son mayores en la AAc (p<0,05). Las diferencias de las medias entre AAnc y AAc son: edad 13,2 años (IC 95%: 8,2-18,2), duración de sintomatología 14,1h (IC 95%: 6,3-21,9), porcentaje de neutrófilos 5,0% (IC 95%: 3,2-6,8), PCR 73,6mg/l (IC 95%: 50,0-97,2) y estancia hospitalaria 2,2 días (IC 95%: 1,4-3,0), con p<0,05. Un modelo basado en parámetros preoperatorios (edad, duración de sintomatología, porcentaje de neutrófilos y PCR) se calcula para predecir la posibilidad de AAc. El área bajo la curva del modelo es 0,80 (IC 95%: 0,75-0,85). Conclusiones: El modelo predice la posibilidad de desarrollar AAc, pero debe validarse de manera prospectiva. (AU)

Background: To analyze whether clinical and analytical parameters differ according to histopathology in cases of acute appendicitis (AA). Methods: This is a retrospective, observational study including patients (>14 years of age) admitted for suspicion of AA from 1 April 2014 to 31 July 2016. Histopathology was divided into complicated (including perforated and gangrenous AA) and uncomplicated appendicitis (phlegmonous). Sex, age, temperature of patients on admission to the Emergency Department, symptom duration, preoperative white blood cell (WBC) count, neutrophil percentage, mean platelet volume (MPV), platelet distribution width (PDW), C-reactive protein (CRP) and hospital stay were compared in the two groups. Results: Three hundred and thirty-five patients were analyzed, and 284 were included. Appendicitis was uncomplicated in 194 (68.3%) and complicated in 90 (31.7%). Age, symptom duration, neutrophil percentage, CRP and hospital stay were higher in the complicated AA group (P < .05). The mean differences between uncomplicated and complicated AA were: age 13.2 years (95% CI: 8.2-18.2), symptom duration 14.1hours (95% CI: 6.3-21.9), neutrophil percentage 5.0% (95% CI: 3.2-6.8), CRP 73.6mg/l (95% CI: 50.0-97.2) and hospital stay 2.2 days (95% CI: 1.4-3.0), with p<0.05 for all these variables. A model based on the preoperative parameters (age, symptom duration, neutrophil percentage and CRP) was calculated to predict the likelihood of complicated AA. The receiver operating characteristic (ROC) of the model had an area under the curve of 0.80 (95% CI 0.75-0.85). Conclusion: This model is able to diagnose complicated AA without the need for imaging techniques, although it must be validated with prospective analysis. (AU)

Evaluation of Preoperative Clinical and Serological Determinations in Complicated Acute Appendicitis: A Score for Predicting Complicated Appendicitis. / Valoración de parámetros clínicos y analíticos preoperatorios en apendicitis aguda complicada. Score para predecir apendicitis complicada.

BACKGROUND: To analyze whether clinical and analytical parameters differ according to histopathology in cases of acute appendicitis (AA). METHODS: This is a retrospective, observational study including patients (>14 years of age) admitted for suspicion of AA from 1 April 2014 to 31 July 2016. Histopathology was divided into complicated (including perforated and gangrenous AA) and uncomplicated appendicitis (phlegmonous). Sex, age, temperature of patients on admission to the Emergency Department, symptom duration, preoperative white blood cell (WBC) count, neutrophil percentage, mean platelet volume (MPV), platelet distribution width (PDW), C-reactive protein (CRP) and hospital stay were compared in the two groups. RESULTS: Three hundred and thirty-five patients were analyzed, and 284 were included. Appendicitis was uncomplicated in 194 (68.3%) and complicated in 90 (31.7%). Age, symptom duration, neutrophil percentage, CRP and hospital stay were higher in the complicated AA group (P < .05). The mean differences between uncomplicated and complicated AA were: age 13.2 years (95% CI: 8.2-18.2), symptom duration 14.1hours (95% CI: 6.3-21.9), neutrophil percentage 5.0% (95% CI: 3.2-6.8), CRP 73.6mg/l (95% CI: 50.0-97.2) and hospital stay 2.2 days (95% CI: 1.4-3.0), with p<0.05 for all these variables. A model based on the preoperative parameters (age, symptom duration, neutrophil percentage and CRP) was calculated to predict the likelihood of complicated AA. The receiver operating characteristic (ROC) of the model had an area under the curve of 0.80 (95% CI 0.75-0.85). CONCLUSION: This model is able to diagnose complicated AA without the need for imaging techniques, although it must be validated with prospective analysis.

Clinical Validation of the Comprehensive Complication Index as a Measure of Postoperative Morbidity at a Surgical Department: A Prospective Study.

OBJECTIVE: Using clinical outcomes, to validate the comprehensive complication index (CCI) as a measure of postoperative morbidity in all patients undergoing surgery at a general surgery department. BACKGROUND: The Clavien-Dindo classification (CDC) is the most widely used system to assess postoperative morbidity. The CCI is a numerical scale based on the CDC. Once validated, it could be used universally to establish and compare the real postoperative complications of each surgical procedure. METHODS: Observational prospective cohort study. All patients who underwent surgery during the 1-year study period were included. All the complications graded with the CDC and related to the initial admission, or until discharge if the patient was readmitted within 90 days of surgery, were included. Surgical procedures were classified according to the operative severity score (OSS) as minor, moderate, major, or major+. The clinical validation of the CCI was performed by assessing its correlation with 4 different clinical outcomes. RESULTS: A total of 1850 patients were included: 513 (27.7%) presented complications and 101 (5.46%) were readmitted. In the multivariate analysis, the CCI and CDC were associated with postoperative stay, prolongation of postoperative stay, readmission, and disability in all OSS groups (P < 0.001). The CCI was superior to the CDC in all models except for prolongation of stay for OSS moderate and major+. CONCLUSIONS: The CCI can be applied in all the procedures carried out at general surgery departments. It is able to determine the morbidity and allows the comparison of the outcomes at different services.

Triple afectación pancreática en una paciente con Von Hippel-Lindau / Triple pancreatic lesion in a patient with Von Hippel-Lindau disease

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Application of RNA-seq and Bioimaging Methods to Study Microbe-Microbe Interactions and Their Effects on Biofilm Formation and Gene Expression.

Complex interactions between pathogenic bacteria, the microbiota, and the host can modify pathogen physiology and behavior. We describe two different experimental approaches to study microbe-microbe interactions in in vitro systems containing surface-associated microbial populations. One method is the application of RNA sequencing (RNA-seq) to determine the transcriptional changes in pathogenic bacteria in response to microbial interspecies interactions. The other method combines flow cell devices for bacterial cultivation and growth with high-resolution bioimaging to analyze the microscale structural organization of interacting microbial populations within mixed-species biofilms.

Elevated parathyroid hormone levels after successful parathyroidectomy for primary hyperparathyroidism: a clinical review.

INTRODUCTION: Surgery for primary hyperparathyroidism (PHPT) is traditionally deemed to be successful if serum calcium levels return to normal 6 months after parathyroidectomy. Regular monitoring of serum calcium and parathyroid hormone (PTH) in the follow-up of patients after parathyroidectomy for PHPT has drawn attention to the presence of a normocalcemic group of patients with elevated PTH (NCePTH) during the post-operative period. The etiological factors and mechanisms underlying this condition, its consequences, and the possibility of treatment are the object of this study. MATERIALS AND METHODS: We conducted an unlimited PubMed search updated on March 31, 2017, which yielded 1628 results. We selected 37 articles, 33 of which included cases of NCePTH in their series and 23 performed statistical studies to assess factors associated with NCePTH. RESULTS: The maximum mean prevalence of NCePTH in the various series was 23.5%, ranging from 3 to 46%. Many factors were associated with NCePTH. The most important were higher pre-operative PTH, low pre-operative 25 (OH) D3, lower pre-operative creatinine clearance and greater adenoma weight. The origin of NCePTH may be multifactorial, since several factors were implicated in the etiology. NCePTH does not seem to be related to an increase in PHPT recurrence, although this possibility should not be dismissed. Vitamin D deficiency should be corrected. Treatment with calcium supplements seems to be clearly beneficial. CONCLUSION: The prevalence of NCePTH is high. The causes of secondary hyperparathyroidism should be investigated carefully. Patients require treatment and long-term follow-up.

Random sequences are an abundant source of bioactive RNAs or peptides.

It is generally assumed that new genes arise through duplication and/or recombination of existing genes. The probability that a new functional gene could arise out of random non-coding DNA is so far considered to be negligible, since it seems unlikely that such a RNA or protein sequence could have an initial function that influences the fitness of an organism. We have here tested this question systematically, by expressing clones with random sequences in E . coli and subjecting them to competitive growth. Contrary to expectations, we find that random sequences with bioactivity are not rare. In our experiments we find that up to 25% of the evaluated clones enhance the growth rate of their cells and up to 52% inhibit growth. Testing of individual clones in competition assays confirms their activity and provides an indication that their activity could be exerted either by the transcribed RNA or the translated peptide. This suggests that transcribed and translated random parts of the genome could indeed have a high potential to become functional. The results also suggest that random sequences may become an effective new source of molecules for studying cellular functions, as well as for pharmacological activity screening.

Trombosis portal y necrosis hepática: complicación excepcional de la pancreatitis aguda / Portal thrombosis and liver necrosis: Exceptional complication of acute pancreatitis

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Utilization and control of ecological interactions in polymicrobial infections and community-based microbial cell factories.

Microbial activities are most often shaped by interactions between co-existing microbes within mixed-species communities. Dissection of the molecular mechanisms of species interactions within communities is a central issue in microbial ecology, and our ability to engineer and control microbial communities depends, to a large extent, on our knowledge of these interactions. This review highlights the recent advances regarding molecular characterization of microbe-microbe interactions that modulate community structure, activity, and stability, and aims to illustrate how these findings have helped us reach an engineering-level understanding of microbial communities in relation to both human health and industrial biotechnology.