Halomonas gemina sp. nov. and Halomonas llamarensis sp. nov., two siderophore-producing organisms isolated from high-altitude salars of the Atacama Desert.

Introduction: This study aimed to identify and characterize novel siderophore-producing organisms capable of secreting high quantities of the iron-binding compounds. In the course of this, two not yet reported halophilic strains designated ATCHAT and ATCH28T were isolated from hypersaline, alkaline surface waters of Salar de Llamará and Laguna Lejía, respectively. The alkaline environment limits iron bioavailability, suggesting that native organisms produce abundant siderophores to sequester iron. Methods: Both strains were characterized by polyphasic approach. Comparative analysis of the 16S rRNA gene sequences revealed their affiliation with the genus Halomonas. ATCHAT showed close similarity to Halomonas salicampi and Halomonas vilamensis, while ATCH28T was related closest to Halomonas ventosae and Halomonas salina. The ability of both strains to secrete siderophores was initially assessed using the chromeazurol S (CAS) liquid assay and subsequently further investigated through genomic analysis and NMR. Furthermore, the effect of various media components on the siderophore secretion by strain ATCH28T was explored. Results: The CAS assay confirmed the ability of both strains to produce iron-binding compounds. Genomic analysis of strain ATCHAT revealed the presence of a not yet reported NRPS-dependant gene cluster responsible for the secretion of siderophore. However, as only small amounts of siderophore were secreted, further investigations did not lie within the scope of this study. Via NMR and genomic analysis, strain ATCH28T has been determined to produce desferrioxamine E (DFOE). Although this siderophore is common in various terrestrial microorganisms, it has not yet been reported to occur within Halomonas, making strain ATCH28T the first member of the genus to produce a non-amphiphilic siderophore. By means of media optimization, the produced quantity of DFOE could be increased to more than 1000 µM. Discussion: Phenotypic and genotypic characteristics clearly differentiated both strains from other members of the genus Halomonas. Average nucleotide identity (ANI) values and DNA-DNA relatedness indicated that the strains represented two novel species. Therefore, both species should be added as new representatives of the genus Halomonas, for which the designations Halomonas llamarensis sp. nov. (type strain ATCHAT = DSM 114476 = LMG 32709) and Halomonas gemina sp. nov. (type strain ATCH28T = DSM 114418 = LMG 32708) are proposed.

Score preoperatorio para la predicción de colecistectomía difícil / Realization of a preoperative score for the prediction of difficult cholecystectomy

Introducción: La colecistectomía es una de las intervenciones quirúrgicas más frecuentes en la práctica médica diaria, la misma no está exenta de complicaciones, especialmente en algunos pacientes con mayor predisposición. Objetivo: Diseñar un score de puntuación preoperatoria para la predicción de la colecistectomía difícil en el área de emergencia y consulta del servicio de Cirugía General del Hospital General del Este "Dr. Domingo Luciani" Caracas - Venezzuela. Métodos: Estudio descriptivo, de diseño longitudinal. Realizado en el período agosto 2018 - agosto 2019. Contó con una muestra de 99 pacientes a los cuales se les aplicó un score predictivo preoperatorio donde se precisaron datos sobre el examen físico, antecedentes personales y quirúrgicos, enfermedades asociadas, exámenes de laboratorio y hallazgos en ultrasonido abdominal, previa firma del consentimiento informado se procedió a evaluar y hacer revisión de los paraclínicos de cada paciente, para luego ser reportado en el score. Resultados: Se registró una edad promedio muestral de 48,25 años ± 1,58, con una mediana de 47 años, el sexo femenino fue el más frecuente (60,61% = 60 casos), de aquellos pacientes clasificados con colecistectomía difícil según el score predictivo experimental predominaron aquellos con presencia de vesícula palpable y antecedentes de colecistitis, el hallazgo de laboratorio más importante fue la leucocitosis (≥ 15x106). Conclusión: El uso del score predictivo planteado permite predecir el riesgo de complicación en una colecistectomía difícil usando como base, las características clínicas y paraclínicas del paciente al momento de su evaluación preoperatoria(AU)

Introduction: Cholecystectomy is one of the most frequent surgical interventions in daily medical practice, it is not without complications, especially in some patients with greater predisposition.. Objective: Design a preoperative score for the prediction of difficult cholecystectomy in the emergency and medical consultation area of the General Surgery service of the Eastern General Hospital "Dr. Domingo Luciani". Methods: A descriptive study, longitudinal design. Performed in the period August 2018-August 2019. It had a sample of 99 patients who were given a preoperative predictive score requiring data on the physical examination, personal and surgical history, associated diseases, laboratory test and findings in abdominal ultrasound, upon signature of the informed consent was proceeded to evaluate and make revision of the paraclinical of each patient, and then be reported in the score. Results: An average sample age of 48.25 years ± 1.58, with a median age of 47 years, the female sex was the most common (60.61%=60 cases), in those patients classified with difficult cholecystectomy, according to the experimental predictive score, predominated those with the presence of palpable vesicle and history of cholecystitis, the most important laboratory finding was leukocytosis (≥ 15x106). Conclusion: The use of the predicted score allows to precise the risk of complication in a difficult cholecystectomy using the clinical and paraclinical characteristics of the patient at the time of their preoperative evaluation(AU)

Associations between bacterial communities and microplastics from surface seawater of the Northern Patagonian area of Chile.

The presence of microplastics in oceans and coastlines has increased during recent years due anthropogenic activities and represents a serious environmental problem. The establishment and assembly of microbial communities in these microplastics, specifically located near aquaculture activities, is not well understood. In this study, we analyzed unique and core members of bacterial communities attached to microplastics collected from three coastal environments of the South Pacific, which represent low, medium and high anthropogenic activity derived from the aquaculture industry. Microplastics were analyzed with Fourier-transform infrared spectroscopy, scanning electron microscopy, and next-generation sequencing to assess the prevailing microplastics types, and to characterize microbial communities attached to them. We identified four main types of microplastics (polypropylene, polyethylene, nylon and polystyrene) and 3102 Operational Taxonomic Units (OTUs) at the sampled sites, which were dominated by the phylum Cyanobacteria, Bacteroidetes and Proteobacteria (mainly Alpha and Gammaproteobacteria). Similarity index analysis showed that bacterial communities in microplastics differed from those found in the surrounding seawaters, and also that they varied among locations, suggesting a role of the environment and level of anthropogenic activities on the plastisphere taxa. Despite this difference, 222 bacterial OTUs were shared among the three sites representing between 34 and 51% of OTUs of each sampled site, and thus constituted a core microbiome of microplastics. Comparison of the core microbiome with bacterial communities of the surrounding seawater suggested that the plastisphere constituted a selective habitat for diverse microbial communities. Computational predictions also provided evidence of significantly enriched functions in the core microbiome. Co-occurrence networks revealed that putative ecological interactions among microplastics OTUs was dominated by positive correlations. To the best of our knowledge, this is the first study that evaluated the composition of microbial communities found in microplastics from the Patagonia region of the Southern Pacific Ocean.

Primary sternal osteomyelitis caused by Salmonella enteritidis / Osteomielitis esternal primaria causada por Salmonella enteritidis

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Thrombolytic treatment for acute prosthetic valve thrombosis: Is it better than surgery?

Prosthetic valve thrombosis (PVT) is a rare but often lethal complication of valve replacement. Despite advances in surgical techniques, surgical mortality remains high and emergent cardiac surgery is not widely available. Herein, we present the case of an acute PVT successfully treated with thrombolytic therapy. A 48-year-old female presented to the emergency department with acute onset of shortness of breath. Her medical history was remarkable for mitral valve replacement at the age of 42 years. Her symptoms began 4 h before, when she suddenly presented severe resting dyspnea. At arrival she showed pulmonary edema and hemodynamic instability. Echocardiography showed a prosthetic mitral valve stuck in a semi-closed position with a gradient of 39 mm Hg. Treatment was started with alteplase and the patient presented marked clinical improvement in subsequent hours. Recent evidence suggests that thrombolysis could be elected as the first choice of treatment in patients with left-side PVT because of the effectiveness, safety profile, availability, and low cost. This case illustrates the importance of prompt diagnosis and treatment and proposes thrombolytic therapy for PVT as an option at least as efficient as and far more accessible than surgery. .