Development and characterization of a bacteriophage cocktail with high lytic efficacy against field-isolated Salmonella enterica.

Salmonella spp. is a prevalent pathogen that causes great public health concern worldwide. Bacteriophage-based cocktails have arisen as an alternative to antibiotics to inhibit the growth of Salmonella. However, the bactericidal effect of bacteriophage cocktails in vivo largely differs from their observed effect in vitro. This is partly because in vitro developments of cocktails do not always consider the bacterial diversity nor the environmental conditions where bacteriophages will have to replicate. Here, we isolated and sequenced 47 bacteriophages that showed variable degrees of lytic activity against 258 Salmonella isolates from a commercial broiler company in Brazil. Three of these bacteriophages were characterized and selected to assemble a cocktail. In vitro quantitative assays determined the cocktail to be highly effective against multiple serovars of Salmonella, including Minnesota and Heidelberg. Remarkably, the in vitro lytic activity of the cocktail was retained or improved in conditions that more closely resembled the chicken gut, such as anaerobiosis, 42°C, and Salmonella mono-strain biofilms. Analysis of bacterial cross-resistance between the 3 bacteriophages composing the cocktail revealed limited or no generation of cross-resistance. Our results highlight the relevance of an optimized flux of work to develop bacteriophage cocktails against Salmonella with high lytic efficacy and strong potential to be applied in vivo in commercial broiler farms.

Unraveling the complex phylogeographic history of freshwater fishes in Lower Central America: A study of the electric fish Brachyhypopomus occidentalis.

Lower Central America (LCA) has a complex biogeographic history shaped by the rise of the Isthmus of Panama and the global climatic oscillations of the Pleistocene. These events have been crucial in structuring biodiversity in LCA, but their consequences for the distribution and partitions of genetic diversity across the region remain to be elucidated. We combined complete mitochondrial genomes and nuclear ultraconserved elements (UCEs) to study the phylogeographic history and population genetic structure of the electric fish Brachyhypopomus occidentalis in LCA. Our results are consistent with the known phylogeographic history of B. occidentalis in LCA, but we update this history in several important ways that help illuminate the phylogeographic history of freshwater fishes in the region. We provide: i) support for three waves of colonization, two of which occurred prior to the final closure of the Panama Isthmus; ii) a more precise understanding of each colonization event, with evidence for a larger footprint of the first event, as well as genetic exchange across the continental divide in subsequent events; and iii) evidence for high levels of previously unrecognized population genetic structure across LCA. This updated model of colonization and diversification of B. occidentalis consists of three waves of dispersal and colonization, which triggered the evolution of geographic breaks in both nuclear and mitochondrial genomes across LCA. These processes are tightly linked to the dynamic uplift of the Isthmus, recent volcanic activity in the region, and the sea-level oscillations of the Pleistocene. These results improve previous phylogeographic inferences regarding the distribution and diversification of freshwater fishes in LCA, and generate testable hypotheses to guide future research exploring the factors shaping biodiversity in the region.

Biological invasions alter the structure of a tropical freshwater food web.

Biological invasions are expected to alter food web structure, but there are limited empirical data directly comparing invaded versus uninvaded food webs, particularly in species-rich, tropical systems. We characterize for the first time the food web of Lake Gatun-a diverse and highly invaded tropical freshwater lake within the Panama Canal. We used stable isotope analysis to reconstruct the trophic structure of the fish community of Lake Gatun and to compare it to that of a minimally invaded reference lake, Lake Bayano. We found significant differences between the trophic structures of these two Neotropical lakes, notably that Lake Gatun's fish community was characterized by a longer food chain, greater isotopic diversity, a broader range of trophic positions and body sizes, and shifts in the isotopic positions of several native taxa relative to Lake Bayano. The degree of isotopic overlap between native and non-native trophic guilds in Lake Gatun was variable, with herbivores exhibiting the lowest (20%-29%) overlap and carnivores the greatest (81%-100%). Overall, our results provide some of the first empirical evidence for the ways in which multiple introduced and native species may partition isotopic space in a species-rich tropical freshwater food web.

The fitness landscape of a community of Darwin's finches.

Divergent natural selection should lead to adaptive radiation-that is, the rapid evolution of phenotypic and ecological diversity originating from a single clade. The drivers of adaptive radiation have often been conceptualized through the concept of "adaptive landscapes," yet formal empirical estimates of adaptive landscapes for natural adaptive radiations have proven elusive. Here, we use a 17-year dataset of Darwin's ground finches (Geospiza spp.) at an intensively studied site on Santa Cruz (Galápagos) to estimate individual apparent lifespan in relation to beak traits. We use these estimates to model a multi-species fitness landscape, which we also convert to a formal adaptive landscape. We then assess the correspondence between estimated fitness peaks and observed phenotypes for each of five phenotypic modes (G. fuliginosa, G. fortis [small and large morphotypes], G. magnirostris, and G. scandens). The fitness and adaptive landscapes show 5 and 4 peaks, respectively, and, as expected, the adaptive landscape was smoother than the fitness landscape. Each of the five phenotypic modes appeared reasonably close to the corresponding fitness peak, yet interesting deviations were also documented and examined. By estimating adaptive landscapes in an ongoing adaptive radiation, our study demonstrates their utility as a quantitative tool for exploring and predicting adaptive radiation.

Infección simultánea del Injerto Renal por virus BK y CMV: reporte de casos / Simultaneous infection of the renal graft by BK virus and CMV: case report

RESUMEN El camino para llegar a la diálisis peritoneal (DP) como tratamiento de la enfermedad renal crónica (ERC) avanzada estuvo jalonado por hitos a lo largo de la historia. Los conocimientos sobre la anatomía del peritoneo fueron aportados por los embalsamadores egipcios, Galeno (siglo II), y Vesalio (siglo XVI). Recién en 1628 Asellius Gaselli describe los capilares linfáticos abdominales. El siglo XIX fue rico en avances: se identificarn la célula como unidad de los seres vivos y el fenómeno de ósmosis (Dutrochet, 1828), los cristaloides y coloides y su pasaje o no a través de una membrana (Graham T, 1850), el flujo de solutos y partículas a través de la membrana peritoneal (v.Recklinghausen, 1863), la absorción de sustancias hipotónicas y el aumento del efluente con las hipertónicas (Wegner G, 1877), y experimentos en animales confirmaron que la remoción de fluidos y otras sustancias ocurría primariamente a través de vasos sanguíneos (Starling & Tubby, 1894). Pero recién en el siglo 20 se utilizó la DP como tratamiento. El primer intento de utilizar el peritoneo para tratar la uremia lo realizó Georg Ganter en 1923, primero en animales con ligadura de uréteres y luego en dos pacientes. Recién en 1937 se publicó el primer caso que sobrevivió a un "lavaje "peritoneal (Wear y col), pero fueron Fine, Frank y Seligman quienes inicialmente en perros nefrectomizados y luego en pacientes con injuria renal aguda (IRA) demostraron que el método no sólo era viable, sino también efectivo. Luego continuaron los progresos, sobre todo para pacientes con IRA, pero también en algunos casos con ERC avanzada: el doble frasco colgante (Maxwell M, 1959), la diálisis crónica intrahospitalaria con cicladora (Tenckoff y col, 1965), las bolsas plásticas para DP, hasta que en 1975 Moncrief y col pusieron en marcha la DP continua ambulatoria, y en 1981 se introdujo la DP automatizada. Los años noventa fueron de expansión de la DP, hoy instalada como una de las alternativas de tratamiento de la ERC avanzada.

ABSTRACT Milestones throughout history marked the path to reach peritoneal dialysis (PD) as a treatment for advanced chronic kidney disease (CKD). The Egyptian embalmers, Galen (2nd century) and Vesalius (16th century) provided knowledge about the anatomy of the peritoneum. It was not until 1628 that Asellius Gaselli described the abdominal lymphatic capillaries. The 19th century was rich in advances: the cell was identified as the unit of living beings and the phenomenon of osmosis (Dutrochet, 1828), crystalloids and colloids and their passage or not through a membrane (Graham T, 1850), the flow of solutes and particles through the peritoneal membrane (Recklinghausen, 1863), the absorption of hypotonic substances and the increase in effluent with hypertonic ones (Wegner G, 1877), and animal experiments confirmed that fluid removal and other substances occurred primarily through blood vessels (Starling & Tubby, 1894). But it was not until the 20th century that PD was applied as treatment. The first attempt to use the peritoneum to treat uremia was made by Georg Ganter in 1923, first in animals with ureteral ligation and then in two patients. It was not until 1937 that the first case that survived a peritoneal "lavage" was published (Wear et al), but it was Fine, Frank and Seligman who initially in nephrectomized dogs and later in patients with acute kidney injury (ARI) demonstrated that the method was not only viable, but also succesful. Then progress continued, especially for patients with ARI, but also in some cases with advanced CKD: the double hanging bottle (Maxwell M, 1959), chronic intrahospital dialysis with a cycler (Tenckoff et al, 1965), plastic bags for PD, until 1975 when Moncrief et al launched continuous ambulatory PD, and in 1981 automated PD was introduced. The 1990s saw the expansion of PD, to date installed as one of treatment alternatives for advanced CKD.

Tuberculosis treatment without rifampin in kidney/kidney-pancreas transplantation: A case series report.

BACKGROUND: The best approach to tuberculosis (TB) treatment in transplanted patients is still unknown. Current guidelines are based on evidence either extrapolated from other populations or observational. Rifampin-containing regimens have strong pharmacokinetic interactions with immunosuppressive regimens, with high rates of organ dysfunction and ∼20% mortality. This report describes the results obtained using non-rifampin-containing regimens to treat confirmed TB in adult patients with kidney/kidney-pancreas transplantation. METHODS: Retrospective data analysis from confirmed TB cases in adult kidney/kidney-pancreas transplant recipients (2006-2019), treated "de novo" with non-rifampin-containing regimens. RESULTS: Fifty-seven patients had confirmed TB. Thirty patients were treated "de novo" with non-rifampin-containing regimens. These patients' mean age was 49.24 (±11.50) years. Induction immunosuppression was used in 22 patients. Maintenance immunosuppression was tacrolimus-mycophenolate-steroids in 13 (43%), sirolimus-mycophenolate-steroids in 6 (20%), and other immunosuppressive regimens in 11 (36%). Belatacept was used in four patients. TB localizations: pulmonary 43%; disseminated 23%; extrapulmonary 33%. Twenty-seven (90%) patients completed treatment with isoniazid, ethambutol, and levofloxacin (12 months, 23; 9 months, 3; 6 months, 1); 12 of these patients also received pyrazinamide for the first 2 months and were cured with functioning grafts. One patient (3%) lost the graft while on treatment. Two patients (7%) died while on TB treatment. Median (range) follow-up after completion of TB treatment was 32 (8-150) months. No TB relapses were observed. CONCLUSIONS: Results with non-rifampin-containing TB treatments in this case series were better (in terms of mortality and graft dysfunction) than those previously described with rifampin-containing regimens in transplanted patients.

Corrosion Resistance of Aluminum Alloy AA2024 with Hard Anodizing in Sulfuric Acid-Free Solution.

In the aeronautical industry, Al-Cu alloys are used as a structural material in the manufacturing of commercial aircraft due to their high mechanical properties and low density. One of the main issues with these Al-Cu alloy systems is their low corrosion resistance in aggressive substances; as a result, Al-Cu alloys are electrochemically treated by anodizing processes to increase their corrosion resistance. Hard anodizing realized on AA2024 was performed in citric and sulfuric acid solutions for 60 min with constant stirring using current densities 3 and 4.5 A/dm2. After anodizing, a 60 min sealing procedure in water at 95 °C was performed. Scanning electron microscopy (SEM) and Vickers microhardness (HV) measurements were used to characterize the microstructure and mechanical properties of the hard anodizing material. Electrochemical corrosion was carried out using cyclic potentiodynamic polarization curves (CPP) and electrochemical impedance spectroscopy (EIS) in a 3.5 wt. % NaCl solution. The results indicate that the corrosion resistance of Al-Cu alloys in citric acid solutions with a current density 4.5 A/dm2 was the best, with corrosion current densities of 2 × 10-8 and 2 × 10-9 A/cm2. Citric acid-anodized samples had a higher corrosion resistance than un-anodized materials, making citric acid a viable alternative for fabricating hard-anodized Al-Cu alloys.

The Association of Preoperative Risk Factors for Laparoscopic Conversion to Open Surgery in Elective Cholecystectomy.

Background: Laparoscopic cholecystectomy is a common operation worldwide, with low mortality (0.01%) and morbidity (2-8%). It has been reported 2.9 to 3.2% of elective laparoscopic cholecystectomies are converted to open surgery. Converted cases are associated with increased complications rates. Method: Two thousand and seventy-five patients, 82.8% females and 17.2% males who underwent elective laparoscopic cholecystectomy in our hospital, between March 1, 2016, and February 28, 2018, were prospectively collected in a database. Pearson's Chi-squared and Fisher's exact tests were used to determine significance, with p <0.05 deemed statistically significant. We analyzed seven risk factors associated with conversion to open surgery; age, gender, body mass index (BMI), previous abdominal surgeries, the presence of contracted gallbladder, Mirizzi syndrome, or choledocholithiasis. Laparoscopic cholecystectomy was performed using a 3-port technique (73%) and a 4-port technique (27%). Results: Finding associated "strong" factors to conversion: male patients, >60-years-old, previous upper abdominal surgery, contracted gallbladder, Mirizzi syndrome or choledocholithiasis. The presence of a higher or lower BMI did not influence the rate of conversion. The most impact association were males over 60 years, and males with an earlier upper abdominal surgery. Conclusion: Laparoscopic cholecystectomy is the gold standard for gallstones and gallbladder disease; however, inflammation, adhesions, and anatomic difficulty continue to challenge the use and safety of this approach in a small number of patients. This study identifies predictors of choice for open cholecystectomy. In view of the raised morbidity and mortality associated with open cholecystectomy, distinguishing these predictors will serve to decrease the rate of conversion and address these factors preoperatively. How to cite this article: Hanson-Viana E, Ayala-Moreno EA, Ortega-Leon LH, et al. The Association of Preoperative Risk Factors for Laparoscopic Conversion to Open Surgery in Elective Cholecystectomy. Euroasian J Hepato-Gastroenterol 2022;12(1):6-9.

Comparison of traditional and DNA metabarcoding samples for monitoring tropical soil arthropods (Formicidae, Collembola and Isoptera).

The soil fauna of the tropics remains one of the least known components of the biosphere. Long-term monitoring of this fauna is hampered by the lack of taxonomic expertise and funding. These obstacles may potentially be lifted with DNA metabarcoding. To validate this approach, we studied the ants, springtails and termites of 100 paired soil samples from Barro Colorado Island, Panama. The fauna was extracted with Berlese-Tullgren funnels and then either sorted with traditional taxonomy and known, individual DNA barcodes ("traditional samples") or processed with metabarcoding ("metabarcoding samples"). We detected 49 ant, 37 springtail and 34 termite species with 3.46 million reads of the COI gene, at a mean sequence length of 233 bp. Traditional identification yielded 80, 111 and 15 species of ants, springtails and termites, respectively; 98%, 37% and 100% of these species had a Barcode Index Number (BIN) allowing for direct comparison with metabarcoding. Ants were best surveyed through traditional methods, termites were better detected by metabarcoding, and springtails were equally well detected by both techniques. Species richness was underestimated, and faunal composition was different in metabarcoding samples, mostly because 37% of ant species were not detected. The prevalence of species in metabarcoding samples increased with their abundance in traditional samples, and seasonal shifts in species prevalence and faunal composition were similar between traditional and metabarcoding samples. Probable false positive and negative species records were reasonably low (13-18% of common species). We conclude that metabarcoding of samples extracted with Berlese-Tullgren funnels appear suitable for the long-term monitoring of termites and springtails in tropical rainforests. For ants, metabarcoding schemes should be complemented by additional samples of alates from Malaise or light traps.

Antimicrobial stewardship programs in adult intensive care units in Latin America: Implementation, assessments, and impact on outcomes.

OBJECTIVE: To assess the impact of antimicrobial stewardship programs (ASPs) in adult medical-surgical intensive care units (MS-ICUs) in Latin America. DESIGN: Quasi-experimental prospective with continuous time series. SETTING: The study included 77 MS-ICUs in 9 Latin American countries. PATIENTS: Adult patients admitted to an MS-ICU for at least 24 hours were included in the study. METHODS: This multicenter study was conducted over 12 months. To evaluate the ASPs, representatives from all MS-ICUs performed a self-assessment survey (0-100 scale) at the beginning and end of the study. The impact of each ASP was evaluated monthly using the following measures: antimicrobial consumption, appropriateness of antimicrobial treatments, crude mortality, and multidrug-resistant microorganisms in healthcare-associated infections (MDRO-HAIs). Using final stewardship program quality self-assessment scores, MS-ICUs were stratified and compared among 3 groups: ≤25th percentile, >25th to <75th percentile, and ≥75th percentile. RESULTS: In total, 77 MS-ICU from 9 Latin American countries completed the study. Twenty MS-ICUs reached at least the 75th percentile at the end of the study in comparison with the same number who remain within the 25th percentile (score, 76.1 ± 7.5 vs 28.0 ± 7.3; P < .0001). Several indicators performed better in the MS-ICUs in the 75th versus 25th percentiles: antimicrobial consumption (143.4 vs 159.4 DDD per 100 patient days; P < .0001), adherence to clinical guidelines (92.5% vs 59.3%; P < .0001), validation of prescription by pharmacist (72.0% vs 58.0%; P < .0001), crude mortality (15.9% vs 17.7%; P < .0001), and MDRO-HAIs (9.45 vs 10.96 cases per 1,000 patient days; P = .004). CONCLUSION: MS-ICUs with more comprehensive ASPs showed significant improvement in antimicrobial utilization.

Factores de riesgo de fracturas no vertebrales en receptores de trasplante renal: ¿Una realidad compleja? / Risk factors for nonvertebral bone fractures in kidney transplant recipients: a complex reality?

RESUMEN Introducción: Las fracturas en el postrasplante renal representan una de las complicaciones que aumentan la morbimortalidad en los pacientes. Objetivo: Determinar los factores de riesgo de trasplante de fracturas no vertebrales en receptores de trasplante renal. Material y métodos: Se analizaron los datos de historias clínicas de 737 pacientes trasplantados renales desde 2009-2015, donde se evaluaron los factores de riesgo de fracturas. Se determinaron como factores generales: edad, sexo; y factores específicos: etiología de la enfermedad renal crónica (ERC), tiempo en diálisis, modalidad de diálisis, características del donante:edad, sexo, tipo de donante vivo y cadavérico (DV, DC), diferentes esquemas de inmunosupresión, rechazos, tratamiento con pulsos de esteroides, uso de bifosfonatos y analitos como parathormona intacta (PTHi), pro-vitamina D (25OHD) y creatininemia (Creats). Criterios de exclusión: pacientes <18 años, retrasplante o trasplantes dobles y menos de 1 año de seguimiento. Resultados: 44 pacientes presentaron 50 fracturas no vertebrales. El 62% de las fracturas se presentaron en los 3 primeros años del trasplante. En el modelo Multivariado se pudo observar que los factores de riesgo generales asociados con riesgo de fracturas fueron la edad avanzada del receptor (aHR por año aumenta 1,03, 95% CI: 1,00-1,05] y el sexo femenino (aHR= 1,60, 95% CI: 0,85-2,99), mientras que los factores de riesgo específicos fueron el tiempo en diálisis (1,07 IC95%:1,02- 1,12), la mayor edad del donante (1,03 IC95:1,00- 1,05) y el déficit de 25OHD (3,17 IC95:1,57- 6,41). Conclusiones: Este estudio permitió evaluar los factores predictivos de fractura en nuestros pacientes con trasplante renal.

ABSTRACT Introduction: Fractures in renal postransplantation represent one of the complications that increase morbidity and mortality in patients. Objective: To determine the risk factors for transplantation of non- vertebral fractures in renal transplant recipients. Methods: The data of clinical histories of 737 renal transplanted patients since 2009 2015 were analyzed, where the risk factors of fractures were evaluated. They were determined as general factors: age, sex; and specific factors: etiology of chronic kidney disease (ERC), dialysis time, dialysis modality, donor characteristics: age, sex, type of donor, living or cadaveric (DV, DC), different immunosuppression treatments, rejections, treatment with steroid pulses, use of bisphosphonates and biochemical parameters like intact parathormone (PTHI), Pro-Vitamin D (25OHD) and Creatininemia (CREATS). Exclusión criteria: patients <18 years, retransplantation or double transplants and follow- up less than 1 year. Results: 44 patients presented 50 non-vertebral fractures. 62% of the fractures were presented in the first 3 years of the transplant. In the multivariate model it was observed that the general risk factors associated with fracture risk were the advanced age of the receptor (aHR per year increases 1.03, 95% CI: 1.00-1.05] and the female sex (aHR = 1.60, 95% CI: 0.85-2.99), while the specific risk factors were dialysis time (1.07 IC95%: 1.02-1.12), the higher age of the donor (1.03 IC95: 1,00-1,05) and the deficit of 25OHD (3.17 IC95: 1.57-6.41). Conclusions: This study allowed to evaluate predictive factors of fracture in our patients with kidney transplantation.

Effect of Cathodic Protection on Reinforced Concrete with Fly Ash Using Electrochemical Noise.

Corrosion of steel reinforcement is the major factor that limits the durability and serviceability performance of reinforced concrete structures. Impressed current cathodic protection (ICCP) is a widely used method to protect steel reinforcements against corrosion. This research aimed to study the effect of cathodic protection on reinforced concrete with fly ash using electrochemical noise (EN). Two types of reinforced concrete mixtures were manufactured; 100% Ordinary Portland Cement (OCP) and replacing 15% of cement using fly ash (OCPFA). The specimens were under-designed protected conditions (-1000 ≤ E ≤ -850 mV vs. Ag/AgCl) and cathodic overprotection (E < -1000 mV vs. Ag/AgCl) by impressed current, and specimens concrete were immersed in a 3.5 wt.% sodium chloride (NaCl) Solution. The analysis of electrochemical noise-time series showed that the mixtures microstructure influenced the corrosion process. Transients of uniform corrosion were observed in the specimens elaborated with (OPC), unlike those elaborated with (OPCFA). This phenomenon marked the difference in the concrete matrix's hydration products, preventing Cl- ions flow and showing passive current and potential transients in most specimens.

Papel de los tejidos orales durante la infección por SARS-CoV-2 / Role of oral tissues in SARS-CoV-2 infection

La actual pandemia de COVID-19 provocada por el virus SARS-CoV-2 es un problema de salud que afecta a la población globalmente. Su desarrollo puede ser asintomático o exhibir manifestaciones clínicas moderadas o severas dependiendo en gran medida de la respuesta inmune de quien la padece. Esta enfermedad afecta principalmente a los pulmones a través del desarrollo del síndrome respiratorio agudo severo (SRAS), tanto como por la «tormenta de citocinas¼, una respuesta inflamatoria exacerbada que podría provocar una falla multisistémica y, en casos severos, la muerte. Se conoce que la enzima convertidora de angiotensina 2 (ECA-2), presente en diversos tejidos del cuerpo, actúa como receptor funcional del virus SARS-CoV-2 facilitando la entrada de éste a las células. Se ha demostrado la presencia de dicho receptor en varios tejidos orales, por lo que se puede considerar a la cavidad bucal como una vía latente de infección por dicho coronavirus, ya que su mecanismo de transmisión es a través de la inhalación de partículas virales, ya sea por vía nasal u oral. Así mismo, la presencia de carga vírica en la saliva y algunos de los síntomas de la COVID-19, por ejemplo la ageusia, pueden indicar la presencia de contagio viral en etapas tempranas. La presente revisión muestra evidencia que sugiere que diversos tejidos en la cavidad oral podrían ser considerados sitios potenciales de contagio por el SARS-CoV-2, teniendo un papel importante en el mecanismo de transmisión y en el desarrollo de coinfecciones (AU)

The COVID-19 pandemic caused by the SARS-CoV-2 virus is currently a global healthcare problem. The onset of this disease can exhibit several clinical manifestations ranging from mild to severe symptoms, depending on the individual's immune response. COVID-19 primarily affects the lungs by developing the Severe Acute Respiratory Syndrome (SARS) and the «cytokine storm¼, an exacerbated inflammatory reaction that can lead to multiorgan failure and consequently death. The angiotensin-converting enzyme 2 (ACE-2), present in several tissues in the human body, is known to act as the functional receptor of the SARS-CoV-2 germ facilitating its entrance into the cells. Such receptor is also present in diverse oral cavity tissues, indicating a latent route of infection due to its influence in the transmission mechanism by inhalation, either oral or nasal, of virus particles. Also, viral load in saliva and taste disorder symptoms like ageusia could indicate a viral infection in its early stages. This article presents evidence suggesting that several tissues in the oral cavity can be considered potential sites of SARS-CoV-2 infection, thus playing an essential role in the transmission mechanism and development of co-infections (AU)

Variante de SARS-CoV-2 VUI 202012/01 (B-1-1-7) en paciente pediátrico, primer reporte de caso en Ecuador / SARS-CoV-2 variant VUI 202012/01 (B-1-1-7) in pediatric patient, first case report in Ecuador

Introducción: Los virus de RNA son conocidos por tener altas tasas de variabilidad genética. El SARS-CoV-2 ha producido diversas variantes en la actualidad que pueden cambiar la presentación clínica. Se presenta el primer caso clínico de la variante B.1.1.7 con estado clínico crítico en un paciente pediátrico y nos alerta sobre la vigilancia de nuevas variantes y la relación de casos críticos en pacientes pediátricos. Caso clínico: Paciente pediátrica con antecedente de parálisis cerebral infantil, atrofia subcortical severa completa, síndrome de Lennox-Gastaut y neumonía recurrente. Presentó una evolución tórpida con necesidad de terapia intensiva por SDRA en relación con la variante B 1.1.7 del SARS-CoV-2. Evolución: Inicialmente fue atendido en un hospital privado, en el cual debido al SDRA necesitó de cuidados intensivos, fue trasladado a un hospital público en el cual posterior a 38 días fue dada de alta por evolución favorable de su cuadro infeccioso. Conclusión: Las nuevas variantes de SARS-CoV-2 pueden mostrar nuevos comportamientos clínicos. A pesar de los antecedentes del paciente estudiado, no se había observado previamente una evolución clínica hacia síntomas graves en pacientes pediátricos con COVID-19. Eso podría estar relacionado con la infección por SARS-CoV-2 variante B.1.1.7 que presentó este paciente.

Introduction: RNA viruses are known to have a high genetic variability. To date, SARS-CoV-2 has produced several variants that can change the clinical presentation of COVID-19. The first clinical case of variant B.1.1.7 with a critical clinical status in a pediatric patient is presented. It indicates that surveillance of new variants and their relationship to critical cases in pediatric patients are required. Clinical case: A pediatric patient with a history of infantile cerebral palsy, complete severe subcortical atrophy, Lennox−Gastaut syndrome, and recurrent pneumonia. She had a slow evolution requiring intensive therapy for acute respiratory distress syndrome (ARDS) that was related to SARS-CoV-2 variant B 1.1.7. Evolution: Initially, she was treated at a private hospital because she required intensive care due to ARDS, and she was then transferred to a public hospital. She was discharged after 35 days due to a favorable evolution of her infectious etiology. Conclusions: New SARS-CoV-2 variants may show new clinical behaviors. Despite this patient's history, a clinical course towards severe symptoms had not been previously observed in pediatric patients with COVID-19. The severe symptoms could be related to the SARS-CoV-2 variant B.1.1.7 infection in this patient.

[Actualidades en la sobrevida del carcinoma hepatocelular].

Objetivo: Realizar una revisión de la literatura actualizada, abordando los aspectos clínicos y epidemiológicos más relevantes asociados con la sobrevida del carcinoma hepatocelular y su relación con las estrategias terapéuticas que han demostrado un mejor resultado. Método: Se realizó una búsqueda bibliográfica empleando las bases de datos electrónicas Medline, Embase, Springerlink y PubMed para identificar documentos publicados desde el 1 de enero de 1985 hasta agosto de 2020. Resultados: Se analizaron el abordaje y el manejo quirúrgico del carcinoma hepatocelular en todo el mundo, comparando las dos principales estrategias terapéuticas que reportan mayor porcentaje de sobrevida global. Conclusiones: En el protocolo de estudio del carcinoma hepatocelular es necesario un enfoque multidisciplinario. Los pacientes con carcinoma hepatocelular avanzado se beneficiarían de una estrategia multimodal individualizada que consista en resección y en otros casos con el trasplante hepático.

Corrosion Behavior of Steel-Reinforced Green Concrete Containing Recycled Coarse Aggregate Additions in Sulfate Media.

Novel green concrete (GC) admixtures containing 50% and 100% recycled coarse aggregate (RCA) were manufactured according to the ACI 211.1 standard. The GC samples were reinforced with AISI 1080 carbon steel and AISI 304 stainless steel. Concrete samples were exposed to 3.5 wt.% Na2SO4 and control (DI-water) solutions. Electrochemical testing was assessed by corrosion potential (Ecorr) according to the ASTM C-876-15 standard and a linear polarization resistance (LPR) technique following ASTM G59-14. The compressive strength of the fully substituted GC decreased 51.5% compared to the control sample. Improved corrosion behavior was found for the specimens reinforced with AISI 304 SS; the corrosion current density (icorr) values of the fully substituted GC were found to be 0.01894 µA/cm2 after Day 364, a value associated with negligible corrosion. The 50% RCA specimen shows good corrosion behavior as well as a reduction in environmental impact. Although having lower mechanical properties, a less dense concrete matrix and high permeability, RCA green concrete presents an improved corrosion behavior thus being a promising approach to the higher pollutant conventional aggregates.

Proteomic fingerprinting of Neotropical hard tick species (Acari: Ixodidae) using a self-curated mass spectra reference library.

Matrix-assisted laser desorption/ionization (MALDI) time-of-flight mass spectrometry is an analytical method that detects macromolecules that can be used for proteomic fingerprinting and taxonomic identification in arthropods. The conventional MALDI approach uses fresh laboratory-reared arthropod specimens to build a reference mass spectra library with high-quality standards required to achieve reliable identification. However, this may not be possible to accomplish in some arthropod groups that are difficult to rear under laboratory conditions, or for which only alcohol preserved samples are available. Here, we generated MALDI mass spectra of highly abundant proteins from the legs of 18 Neotropical species of adult field-collected hard ticks, several of which had not been analyzed by mass spectrometry before. We then used their mass spectra as fingerprints to identify each tick species by applying machine learning and pattern recognition algorithms that combined unsupervised and supervised clustering approaches. Both Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA) classification algorithms were able to identify spectra from different tick species, with LDA achieving the best performance when applied to field-collected specimens that did have an existing entry in a reference library of arthropod protein spectra. These findings contribute to the growing literature that ascertains mass spectrometry as a rapid and effective method to complement other well-established techniques for taxonomic identification of disease vectors, which is the first step to predict and manage arthropod-borne pathogens.

The Microbiome of Neotropical Water Striders and Its Potential Role in Codiversification.

Insects host a highly diverse microbiome, which plays a crucial role in insect life. However, the composition and diversity of microbiomes associated with Neotropical freshwater insects is virtually unknown. In addition, the extent to which diversification of this microbiome is associated with host phylogenetic divergence remains to be determined. Here, we present the first comprehensive analysis of bacterial communities associated with six closely related species of Neotropical water striders in Panama. We used comparative phylogenetic analyses to assess associations between dominant bacterial linages and phylogenetic divergence among species of water striders. We found a total of 806 16S rRNA amplicon sequence variants (ASVs), with dominant bacterial taxa belonging to the phyla Proteobacteria (76.87%) and Tenericutes (19.51%). Members of the α- (e.g., Wolbachia) and γ- (e.g., Acinetobacter, Serratia) Proteobacteria, and Mollicutes (e.g., Spiroplasma) were predominantly shared across species, suggesting the presence of a core microbiome in water striders. However, some bacterial lineages (e.g., Fructobacillus, Fluviicola and Chryseobacterium) were uniquely associated with different water strider species, likely representing a distinctive feature of each species' microbiome. These findings indicate that both host identity and environmental context are important drivers of microbiome diversity in water striders. In addition, they suggest that diversification of the microbiome is associated with diversification in water striders. Although more research is needed to establish the evolutionary consequences of host-microbiome interaction in water striders, our findings support recent work highlighting the role of bacterial community host-microbiome codiversification.