Unveiling microbial guilds and symbiotic relationships in Antarctic sponge microbiomes.

Marine sponges host diverse microbial communities. Although we know many of its ecological patterns, a deeper understanding of the polar sponge holobiont is still needed. We combine high-throughput sequencing of ribosomal genes, including the largest taxonomic repertoire of Antarctic sponge species analyzed to date, functional metagenomics, and metagenome-assembled genomes (MAGs). Our findings show that sponges harbor more exclusive bacterial and archaeal communities than seawater, while microbial eukaryotes are mostly shared. Furthermore, bacteria in Antarctic sponge holobionts establish more cooperative interactions than in sponge holobionts from other environments. The bacterial classes that established more positive relations were Bacteroidia, Gamma- and Alphaproteobacteria. Antarctic sponge microbiomes contain microbial guilds that encompass ammonia-oxidizing archaea, ammonia-oxidizing bacteria, nitrite-oxidizing bacteria, and sulfur-oxidizing bacteria. The retrieved MAGs showed a high level of novelty and streamlining signals and belong to the most abundant members of the main microbial guilds in the Antarctic sponge holobiont. Moreover, the genomes of these symbiotic bacteria contain highly abundant functions related to their adaptation to the cold environment, vitamin production, and symbiotic lifestyle, helping the holobiont survive in this extreme environment.

Ongoing diversification of the global fish pathogen Piscirickettsia salmonis through genetic isolation and transposition bursts.

The management of bacterial pathogens remains a key challenge of aquaculture. The marine gammaproteobacterium Piscirickettsia salmonis is the etiological agent of piscirickettsiosis and causes multi-systemic infections in different salmon species, resulting in considerable mortality and substantial commercial losses. Here, we elucidate its global diversity, evolution, and selection during human interventions. Our comprehensive analysis of 73 closed, high quality genome sequences covered strains from major outbreaks and was supplemented by an analysis of all P. salmonis 16S rRNA gene sequences and metagenomic reads available in public databases. Genome comparison showed that Piscirickettsia comprises at least three distinct, genetically isolated species of which two showed evidence for continuing speciation. However, at least twice the number of species exist in marine fish or seawater. A hallmark of Piscirickettsia diversification is the unprecedented amount and diversity of transposases which are particularly active in subgroups undergoing rapid speciation and are key to the acquisition of novel genes and to pseudogenization. Several group-specific genes are involved in surface antigen synthesis and may explain the differences in virulence between strains. However, the frequent failure of antibiotic treatment of piscirickettsiosis outbreaks cannot be explained by horizontal acquisition of resistance genes which so far occurred only very rarely. Besides revealing a dynamic diversification of an important pathogen, our study also provides the data for improving its surveillance, predicting the emergence of novel lineages, and adapting aquaculture management, and thereby contributes towards the sustainability of salmon farming.

Clinical Efficacy of SARS-CoV-2 Vaccination in Hemodialysis Patients.

Introduction: The COVID-19 pandemic is a global public health problem. Patients with end-stage renal disease on hemodialysis are at a higher risk of infection and mortality than the general population. Worldwide, a vaccination campaign has been developed that has been shown to reduce severe infections and deaths in the general population. However, there are currently limited data on the clinical efficacy of vaccinations in the hemodialysis population. Methods: A national multicenter observational cohort was performed in Chile to evaluate the clinical efficacy of anti-SARS-CoV-2 vaccination in end-stage renal disease patients on chronic hemodialysis from February 2021 to August 2021. In addition, the BNT162b2 (Pfizer-BioNTech) and CoronaVac (Sinovac) vaccines were evaluated. The efficacy of vaccination in preventing SARS-CoV-2 infection, hospitalizations, and deaths associated with COVID-19 was determined. Results: A total of 12,301 patients were evaluated; 10,615 (86.3%) received a complete vaccination (2 doses), 490 (4.0%) received incomplete vaccination, and 1196 (9.7%) were not vaccinated. During follow-up, 1362 (11.0%) patients developed COVID-19, and 150 died (case fatality rate: 11.0%). The efficacy of the complete vaccination in preventing infection was 18.1% (95% confidence interval [CI]:11.8-23.8%), and prevention of death was 66.0% (95% CI:60.6-70.7%). When comparing both vaccines, BNT162b2 and CoronaVac were effective in reducing infection and deaths associated with COVID-19. Nevertheless, the BNT162b2 vaccine had higher efficacy in preventing infection (42.6% vs. 15.0%) and deaths (90.4% vs. 64.8%) compared to CoronaVac. Conclusion: The results of our study suggest that vaccination against SARS-CoV-2 in patients on chronic hemodialysis was effective in preventing infection and death associated with COVID-19.

Gastrostomy: A percutaneous laparoscopic technique.

Several techniques are available for a gastrostomy concomitant with a major abdominal surgery, i.e., there is no 'standard' technique. Here, we present our results of a novel concomitant gastrostomy developed for the Nissen fundoplication. It combines the laparoscopic instrumentation with the kit for percutaneous endoscopic gastrostomy. Once the fundoplication is completed, the gastrostomy is performed in three stages. First, with the orogastric tube and snare, the loop of wire is left in the peritoneal cavity; next, a guide-wire introduced into the peritoneal cavity from the abdominal wall, is taken with the loop, and retrieved at the mouth; finally, the gastrostomy tube is pulled with the guide-wire from mouth to abdominal wall. Only laparoscopic instrumentation is used to choose the site in the stomach, and to perform the puncture; hence, the gastroscope is unnecessary. By choosing the proper sites, stomata are aligned and free of lateral strains making the gentle pressure of the dome enough to appose gastric and abdominal walls; hence, stitches become unnecessary to affix the walls. This percutaneous laparoscopic gastrostomy is simple, brief (ca 21 min), well tolerated, without complications during the intervention or the postoperatory period, reproducible, and of low cost, and exceptional skills are not required. Finally, laparoscopic protocols for a primary gastrostomy may dispel some complications by choosing a 'pull' to install the gastrostomy tube as reported here, instead of the usual 'push'.

De novo assembly, characterization of tissue-specific transcriptomes and identification of immune related genes from the scallop Argopecten purpuratus.

The scallop Argopecten purpuratus is one of the most economically important cultured mollusks on the coasts from Chile and Peru but its production has declined, in part, due to the emergence of mass mortality events of unknown origin. Driven by this scenario, increasing progress has been made in recent years in the comprehension of immune response mechanisms in this species. However, it is still not entirely understood how different mucosal interfaces participate and cooperate with the immune competent cells, the hemocytes, in the immune defense. Thus, in this work we aimed to characterize the transcriptome of three tissues with immune relevance from A. purpuratus by next-generation sequencing and de novo transcriptome assembly. For this, 18 cDNA libraries were constructed from digestive gland, gills and hemocytes tissues of scallops from different immune conditions and sequenced by the Illumina HiSeq4000 platform. A total of 967.964.884 raw reads were obtained and 967.432.652 clean reads were generated. The clean reads were de novo assembled into 46.601 high quality contigs and 32.299 (69.31%) contigs were subsequently annotated. In addition, three de novo specific assemblies were performed from clean reads obtained from each tissue cDNA libraries for their comparison. Gene ontology (GO) and KEGG analyses revealed that annotated sequences from digestive gland, gills and hemocytes could be classified into both general and specific subcategory terms and known biological pathways, respectively, according to the tissue nature. Finally, several immune related candidate genes were identified, and the differential expression of tissue-specific genes was established, suggesting they could display specific roles in the host defense. The data presented in this study provide the first insight into the tissue specific transcriptome profiles of A. purpuratus, which should be considered for further research on the interplay between the hemocytes and mucosal immune responses.

[Hepatocellular damage, proteinuria and autoimmunity: multisystemic disorder or coexistence of diseases?] / Daño hepatocelular, proteinuria y autoinmunidad: ¿enfermedad multisistémica o coincidencia de enfermedades? Caso clínico.

We report a 19 years old male presenting with knee pain, elevated liver enzymes and proteinuria. Further investigation found positive antinuclear and anti-smooth muscle antibodies and a liver biopsy revealed the presence of an autoimmune hepatitis. Treatment with corticosteroids and azathioprine was started, resulting in normalization of liver enzymes but proteinuria persisted and a kidney biopsy disclosed a focal segmental glomerulosclerosis. The use of lisinopril resulted in a significative reduction of proteinuria and, after 30 months of follow up, he continues with azathioprine, lisinopril and a low prednisone dose without evidence of liver or kidney disease activity.

Selection and validation of reliable housekeeping genes to evaluate Piscirickettsia salmonis gene expression.

Piscirickettsia salmonis is a highly aggressive facultative intracellular bacterium that challenges the sustainability of Chilean salmon production. Due to the limited knowledge of its biology, there is a need to identify key molecular markers that could help define the pathogenic potential of this bacterium. We think a model system should be implemented that efficiently evaluates the expression of putative bacterial markers by using validated, stable, and highly specific housekeeping genes to properly select target genes, which could lead to identifying those responsible for infection and disease induction in naturally infected fish. Here, we selected a set of validated reference or housekeeping genes for RT-qPCR expression analyses of P. salmonis under different growth and stress conditions, including an in vitro infection kinetic. After a thorough screening, we selected sdhA as the most reliable housekeeping gene able to represent stable and highly specific host reference genes for RT-qPCR-driven P. salmonis analysis.

Daño hepatocelular, proteinuria y autoinmunidad: ¿enfermedad multisistémica o coincidencia de enfermedades? Caso clínico / Hepatocellular damage, proteinuria and autoimmunity: multisystemic disorder or coexistence of diseases?

We report a 19 years old male presenting with knee pain, elevated liver enzymes and proteinuria. Further investigation found positive antinuclear and anti-smooth muscle antibodies and a liver biopsy revealed the presence of an autoimmune hepatitis. Treatment with corticosteroids and azathioprine was started, resulting in normalization of liver enzymes but proteinuria persisted and a kidney biopsy disclosed a focal segmental glomerulosclerosis. The use of lisinopril resulted in a significative reduction of proteinuria and, after 30 months of follow up, he continues with azathioprine, lisinopril and a low prednisone dose without evidence of liver or kidney disease activity.

Determinación de los niveles séricos de vitamina D en los pacientes diagnosticados con Esclerosis múltiple y su relación con la severidad y el comportamiento de la enfermedad en el "Hospital Metropolitano de Quito" y en el "Hospital Carlos Andrade Marín" / Determination of vitamin D serum levels in patients diagnosed with multiple sclerosis and their relationship with the severity and illness behavior in the Metropolitan Hospital in Quito and Carlos Andrade Marín Hospital

Introducción: El estudio pretende relacionar los niveles séricos de vitamina D, en pacientes con Esclerosis Múltiple (EM), con la severidad y el comportamiento de la enfermedad. Materiales y Métodos: Reclutamos 81 pacientes con EM, de los cuales se obtuvo una muestra de 50 pacientes para compararlos con 50 sujetos sanos, pareados por edad, sexo y color de la piel. La severidad de la enfermedad se evaluó con la escala de Kurtzke, número de recaídas, exposición solar, etc. Resultados: La concentración sérica de vitamina D en pacientes con EM (M=31.9 SD=12.3 ng/ml) fue similar a la de los controles (M=30.3 SD= 8.0 ng/ml; p=0.53). La prevalencia de insuficiencia de vitamina D fue del 42% (n=21) entre los casos y 46% (n=23) entre los controles, p>0.05). Se calculó la relación entre los niveles óptimos de Vitamina D (> 40, ng/ml) con un bajo grado de discapacidad, definida como un valor en la escala de Kurtzke < 3.5 [χ2(1, N=100)= 3.13 p=0.3]. El promedio de vitamina D en los pacientes con más de una recaída fue de 31.0 ng /ml y con menos de una recaída, 32.5 ng/ml fue similar (p=0.66). Discusión: No hubo diferencia significativa en las concentraciones séricas de vitamina D en pacientes con EM y sujetos sanos, pareados por género, edad y color de la piel. No hubo correlación entre el nivel de vitamina D y el grado de discapacidad medido por la escala de Kurtzke ni con el número de recaídas.

Introduction: The study seeks to relate vitamin D serum levels in Multiple Sclerosis (MS) patients with disease severity and its progression. Methods: From eighty one MS patients enrolled, fifty were selected to compare to healthy subjects, paired according to age, gender and skin color. Disease severity was assessed using the Kurtzke severity scale, relapses number, solar exposure. Results: The mean vitamin D serum concentration in MS patients (M= 31.9 SD=12.3 ng/ml) was similar to controls' (M=30.31 SD=8.0 ng/ml; p=0.53). The prevalence of vitamin D insufficiency was 42% (n=22) among cases and 46% (n=23) among controls (p=0.91). The relationship between an optimal vitamin D serum concentration (>40 ng/ml) and a low grade of disability, using a cutoff point in the Kurtzke scale < 3.5, was assessed and a non-significant correlation was found [χ2(1, N=100)= 3.13 p=0.3]. The mean vitamin D level among patients with more than one relapse (M=31.0 ng/ml) was similar to those with less than one relapse (M=32.49, p=0.66). Discusion: There was no difference of vitamin D serum levels between MS patients and the general population. A weak and not significant correlation was found with the degree of disability, measured by the Kurtzke severity scale, and also with the number of relapses.

In sílico identification and characterization of putative Dot/Icm secreted virulence effectors in the fish pathogen Piscirickettsia salmonis.

Piscirickettsia salmonis seriously affects the Chilean salmon industry. The bacterium is phylogenetically related to Legionella pneumophila and Coxiella burnetii, sharing a Dot/Icm secretion system with them. Although it is well documented that L. pneumophila and C. burnetii secrete different virulence effectors via this Dot/Icm system in order to attenuate host cell responses, to date there have been no reported virulence effectors secreted by the Dot/Icm system of P. salmonis. Using several annotations of P. salmonis genome, here we report an in silico analyses of 4 putative Dot/Icm effectors. Three of them contain ankyrin repeat domains and the typical conserved 3D structures of this protein family. The fourth one is highly similar to one of the Dot/Icm-dependent effectors of L. pneumophila. Additionally, all the potential P. salmonis effectors contain a classical Dot/Icm secretion signal in their C-terminus, consisting of: an E-Block, a hydrophobic residue in -3 or -4 and an electronegative charge. Finally, qPCR analysis demonstrated that these proteins are overexpressed early in infection, perhaps contributing to the generation of a replicative vacuole, a key step in the neutralizing strategy proposed for the Dot/Icm system. In summary, this report identifies four Dot/Icm-dependent effectors in P. salmonis.

[Enterocolitis, antimicrobials and hemolytic-uremic syndrome in children: Review of a concept]. / Enterocolitis, antimicrobianos y síndrome hemolítico urémico en niños: Revisión de un concepto.

BACKGROUND: Treatment of children with Escherichia coli O157:H7 enterocolitis could be related with risk of Hemolytic-Uremic Syndrome (HUS). The proscription of antibiotics use until cultures ruled out this infection has been proposed (Wong et al.). This concept became generalized causing dilemma in clinical decisions and research. The objective of this study was to review the evidence related with this topic. METHODS: A 1999-2011 literature review of studies related with E.coli O157:H7, antibiotics and HUS in children. RESULTS: We found one randomized controlled trial, three cohort studies, one case-control and one meta-analysis with pediatric data on the topic. After methodological and metrical analysis, five studies showed opposite results as compared to Wong et al. All had statistical power enough to detect Wong's association but did not happen. Wong's study had no statistical power to detect risk ratios ≤ 11. CONCLUSION: These results are neither reproducible nor generalizable, consequently clinical decisions should be solved following local epidemiology.

To remove or not remove...asymptomatic sewing needle within hepatic right lobe in an infant.

PURPOSE/BACKGROUND: The ingestion or accidental insertion of foreign bodies is extremely rare before 6 months of age. We report the case of a 3-month-old infant with a sewing needle into the right hepatic lobe, without symptoms. The extraction was performed through laparotomy. The issue is revisited, and the decision making tree is discussed.

Guía clínica para el diagnóstico y cuidado de niños/adolescentes con bronquiolitis obliterante post-infecciosa, 2009 / Clinical guidelines for the diagnosis and care of children and adolescents with post-infectious bronchiolitis obliterans, 2009

La bronquiolitis obliterante (BO) es un síndrome clínico poco frecuente en niños, caracterizado por la obstrucción crónica al flujo de aire asociado a cambios inflamatorios y distintos grados de fibrosis en la vía aérea pequeña. Si bien existen muchas etiologías, la causa mas frecuente se asocia a infeccionesrespiratorias virales, principalmente adenovirus. No existe un consenso para establecer su diagnóstico; sin embargo, se considera un espectro de síntomas persistentes asociados a un patrón en mosaico, bronquiectasias y atelectasias persistentes. El rol de la biopsia pulmonar ha sido cuestionado por subajo rendimiento, invasividad y complicaciones. No existe un tratamiento específico por lo que elmanejo es soporte. Probablemente la mejor estrategia constituya el empleo de antibióticos en forma agresiva, soporte kinésico y nutricional constante y una precoz rehabilitación pulmonar. Estas guías clínicas representan un esfuerzo multidisciplinario, basado en evidencias actuales para brindarherramientas prácticas para el diagnóstico y cuidado de niños y adolescentes con BO post infecciosa.

Topsy-turvy heart with associated congenital tracheobronchial stenosis and airway compression requiring surgical reconstruction.

We describe a case of "topsy-turvy heart" that necessitated simultaneous left tracheobronchial repair, aortic arch reconstruction, and bronchial stenting in an 11-month-old girl. This case highlights the significant therapeutic dilemmas clinicians are faced with when dealing with conditions having an unknown natural history and unpredictable surgical outcomes, and reinforces the need for these patients to be managed by a multidisciplinary team approach.

Thoracoscopic versus open resection of congenital lung lesions: a case-matched study.

PURPOSE: The purpose of the study was to compare the outcomes in children undergoing thoracoscopic versus open resection of congenital lung lesions. METHODS: Retrospective review of 12 consecutive children (<3 years of age) undergoing thoracoscopic resection of a congenital lung lesion between 2004 and 2005 was performed. Intraoperative and early postoperative results were compared with randomly selected age- and sex-matched (2:1) patients undergoing thoracotomy between 2000 and 2005. RESULTS: Twelve children underwent thoracoscopic resection and were compared with 24 that underwent thoracotomy. Seventy five percent of the lesions in both groups were congenital cystic adenomatoid malformations. There were no major intraoperative complications. Two thoracoscopic procedures were converted to a thoracotomy. Perioperative outcomes including operative time, length of stay, duration and volume of chest tube drainage, and dose and duration of intravenous opioids were similar for the procedures. However, children undergoing thoracoscopic procedures were less likely (odds ratio = 0.07) to have received adjunctive regional anesthesia. Overall morbidity was 33% thoracoscopic and 25% open (P = .70). CONCLUSION: Thoracoscopic resection is a safe and feasible alternative to open resection of congenital lung lesions. Examination of long-term advantages of the thoracoscopic approach such as decreased risk of chest wall deformity and scoliosis and improved cosmesis will require longer follow-up.

[Usefulness of C-reactive protein for the diagnosis of bacterial infections in children. A review]. / Existen bases para el uso de la proteína C reactiva en la detección de infecciones bacterianas en niños?

Although C-Reactive protein (CRP) was described more than 70 years ago and it still is commonly used in practice, studies exploring its usefulness persist while some propose its replacement by other inflammatory acute-phase-mediators. The aim of this clinical review is to answer the question if CRP measurement warrant clinical decisions for febrile children because it discriminates between bacterial from non bacterial etiologies. We made a systematic search by means of MEDLINE, SciELO and LILACS with the following MESH terms: "C-reactive protein", "bacterial", "infection", "children", "diagnosis" or "detection", besides the Haynes selector for articles on diagnosis, between 1950 and 2004. Selection data extraction and critical appraisal were independently made by the two authors, following standard criteria. We selected 7 primary articles, 3 clinical reviews and two randomized clinical trials. There was no disagreement between reviewers. Only one of the clinical reviews followed standard guidelines; two reviews concluded that no isolated CRP values would warrant to make decisions on starting or withholding antimicrobial therapy in febrile children. All primary articles showed methodological flaws in basic validity criteria. Both randomized clinical trials showed that CRP results did not change either doctor's decisions about antimicrobial prescriptions nor the studied patients' prognosis. We did not find evidences that could warrant the use of CRP for the defined problem in Pediatrics. Main problems affecting validity of studies on CRP as diagnostic resource are the lack of laboratory methods uniformity--including the gold standard make up--the heterogeneity of cut off points, clinical spectrum inappropriateness of study groups as well as the resulting diversity of the fixed indexes values. Moreover, no validation of this test in children population has been made so far.