FACTORES DE VIRULENCIA DE Vibrio mimicus/ Vibrio mimicus VIRULENCE FACTORS

Vibrio mimicus es una bacteria Gram-negativa que ha sido vinculada como agente causal de enfermedades en humanos en diferentes países. Habita naturalmente en ecosistemas marinos y ha sido aislada de diferentes fuentes, como alimentos marinos hasta casos clínicos. Existen varios estudios donde se ha documentado la presencia de varios factores de virulencia en V. mimicus, como la producción de enterotoxinas, hemolisinas, presencia de sideróforos y hemaglutininas, entre otros. En esta revisión se describen los factores de virulencia más importantes reportados en V. mimicus, los cuales ponen de manifiesto el potencial patógeno que representa dicha bacteria. ABSTRACT Vibrio mimicus is a Gram-negative bacterium that has been linked as a causative agent of human diseases in diff erent countries. It is found naturally in marine ecosystems and has been isolated from diff erent sources, from seafood to clinical cases. In several studies the presence of several virulence factors in V. mimicus has been documented such as hemolysins, enterotoxins, siderophores, hemagglutinins, among others. This review describes the most important virulence factors reported in V. mimicus, which highlight the pathogenic potential that this bacterium represents

Molecular and Genomic Characterization of Vibrio mimicus Isolated from a Frozen Shrimp Processing Facility in Mexico.

Vibrio mimicus is a gram-negative bacterium responsible for diseases in humans. Three strains of V. mimicus identified as V. mimicus 87, V. mimicus 92 and V. mimicus 93 were isolated from a shrimp processing facility in Guaymas, Sonora, Mexico. The strains were analyzed using several molecular techniques and according to the cluster analysis they were different, their similarities ranged between 51.3% and 71.6%. ERIC-PCR and RAPD (vmh390R) were the most discriminatory molecular techniques for the differentiation of these strains. The complete genomes of two strains (V. mimicus 87, renamed as CAIM 1882, and V. mimicus 92, renamed as CAIM 1883) were sequenced. The sizes of the genomes were 3.9 Mb in both strains, with 2.8 Mb in ChI and 1.1 Mb in ChII. A 12.7% difference was found in the proteome content (BLAST matrix). Several virulence genes were detected (e.g. capsular polysaccharide, an accessory colonization factor and genes involved in quorum-sensing) which were classified in 16 categories. Variations in the gene content between these genomes were observed, mainly in proteins and virulence genes (e.g., hemagglutinin, mobile elements and membrane proteins). According to these results, both strains were different, even when they came from the same source, giving an insight of the diversity of V. mimicus. The identification of various virulence genes, including a not previously reported V. mimicus gene (acfD) in ChI in all sequenced strains, supports the pathogenic potential of this species. Further analysis will help to fully understand their potential virulence, environmental impact and evolution

Core and Accessory Genome Analysis of Vibrio mimicus

© 2021 by the authors.Vibrio mimicus is an emerging pathogen, mainly associated with contaminated seafood consumption. However, little is known about its evolution, biodiversity, and pathogenic potential. This study analyzes the pan-, core, and accessory genomes of nine V. mimicus strains. The core genome yielded 2424 genes in chromosome I (ChI) and 822 genes in chromosome II (ChII), with an accessory genome comprising an average of 10.9% of the whole genome for ChI and 29% for ChII. Core genome phylogenetic trees were obtained, and V. mimicus ATCC-33654 strain was the closest to the outgroup in both chromosomes. Additionally, a phylogenetic study of eight conserved genes (ftsZ, gapA, gyrB, topA, rpoA, recA, mreB, and pyrH), including Vibrio cholerae, Vibrio parilis, Vibrio metoecus, and Vibrio caribbenthicus, clearly showed clade differentiation. The main virulence genes found in ChI corresponded with type I secretion proteins, extracellular components, flagellar proteins, and potential regulators, while, in ChII, the main categories were type-I secretion proteins, chemotaxis proteins, and antibiotic resistance proteins. The accessory genome was characterized by the presence of mobile elements and toxin encoding genes in both chromosomes. Based on the genome atlas, it was possible to characterize differential regions between strains. The pan-genome of V. mimicus encompassed 3539 genes for ChI and 2355 genes for ChII. These results give us an insight into the virulence and gene content of V. mimicus, as well as constitute the first approach to its diversity.This research was supported by CONACYT (National Council for Science and Technology), who provided a student scholarship (Grant No. 98245) and internal institutional funds from CIAD Guaymas and CIAD HermosilloPeer reviewe

Maximum likelihood (ML) and Neighbor joining (NJ) phylogenetic trees of 28 core genome virulence genes.

<p>The ML and NL phylogenetic trees of both chromosomes of <i>V</i>. <i>mimicus</i> CAIM 1882, 1883, 602 and <i>V</i>. <i>mimicus</i> 451 were obtained using MEGA, where <i>V</i>. <i>cholerae</i> O1 biovar El Tor N16961 [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0144885#pone.0144885.ref034" target="_blank">34</a>] was used as outgroup.</p

BLAST matrix (proteome comparison) of <i>V</i>. <i>mimicus</i> 451, <i>V</i>. <i>mimicus</i> CAIM 602, <i>V</i>. <i>mimicus</i> CAIM 1882 and <i>V</i>. <i>mimicus</i> CAIM 1883.

<p>The BLAST matrix was obtained using CMG-biotools [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0144885#pone.0144885.ref035" target="_blank">35</a>].</p

Genome Atlas obtained of <i>V</i>. <i>mimicus</i> CAIM 602 (green), CAIM 1882 (red), CAIM 1883 (blue) and <i>V</i>. <i>mimicus</i> 451 (as control strain).

<p>The atlas was constructed with GeneWiz Browser 0.94. From the inner ring to the outer ring: Percent AT, GC Skew, Global Inverted Repeats, Global Direct Repeats, Position Preference, Stacking Energy and Intrinsic Curvature.</p

Composite dendrogram for the three strains of <i>V</i>. <i>mimicus</i> isolated from frozen shrimp process (<i>V</i>. <i>mimicus</i> 87, 92 and 93) and <i>V</i>. <i>mimicus</i> CAIM 602T (type strain).

<p>The dendrogram and a similarity matrix were obtained by a cluster analysis of ERIC-PCR, GTG-5, RAPD and ARDRA (Bionumerics, Applied Maths, Inc).</p

Dendrograms of ERIC-PCR, RAPD, GTG-5PCR and ARDRA used for the analysis of <i>V</i>. <i>mimicus</i> 87, 92, 93 and CAIM 602 (type strain).

<p>The images were analyzed with Bionumerics software (Applied Maths, Inc.) with Dice correlation coefficient for the distance matrix and UPGMA with optimization set at 1% to create the dendrogram.</p

Coordinated metabolic transitions and gene expression by NAD+ during adipogenesis

International audienceAdipocytes are the main cell type in adipose tissue, which is a critical regulator of metabolism, highly specialized in storing energy as fat. Adipocytes differentiate from multipotent mesenchymal stromal cells (hMSCs) through adipogenesis, a tightly controlled differentiation process involving close interplay between metabolic transitions and sequential programs of gene expression. However, the specific gears driving this interplay remain largely obscure. Additionally, the metabolite nicotinamide adenine dinucleotide (NAD +) is becoming increasingly recognized as a regulator of lipid metabolism, and a promising therapeutic target for dyslipidemia and obesity. Here, we explored how NAD + bioavailability controls adipogenic differentiation from hMSC. We found a previously unappreciated repressive role for NAD + on adipocyte commitment, while a functional NAD +-dependent deacetylase SIRT1 appeared crucial for terminal differentiation of pre-adipocytes. Repressing NAD + biosynthesis during adipogenesis promoted the adipogenic transcriptional program, while two-photon microscopy and extracellular flux analyses suggest that SIRT1 activity mostly relies on the metabolic switch. Interestingly, SIRT1 controls subcellular compartmentalization of redox metabolism during adipogenesis

Whole-exome sequencing of 81 individuals from 27 multiply affected bipolar disorder families

Bipolar disorder (BD) is a highly heritable neuropsychiatric disease characterized by recurrent episodes of depression and mania. Research suggests that the cumulative impact of common alleles explains 25-38% of phenotypic variance, and that rare variants may contribute to BD susceptibility. To identify rare, high-penetrance susceptibility variants for BD, whole-exome sequencing (WES) was performed in three affected individuals from each of 27 multiply affected families from Spain and Germany. WES identified 378 rare, non-synonymous, and potentially functional variants. These spanned 368 genes, and were carried by all three affected members in at least one family. Eight of the 368 genes harbored rare variants that were implicated in at least two independent families. In an extended segregation analysis involving additional family members, five of these eight genes harbored variants showing full or nearly full cosegregation with BD. These included the brain-expressed genes RGS12 and NCKAP5, which were considered the most promising BD candidates on the basis of independent evidence. Gene enrichment analysis for all 368 genes revealed significant enrichment for four pathways, including genes reported in de novo studies of autism (p(adj) < 0.006) and schizophrenia (p(adj) = 0.015). These results suggest a possible genetic overlap with BD for autism and schizophrenia at the rare-sequence-variant level. The present study implicates novel candidate genes for BD development, and may contribute to an improved understanding of the biological basis of this common and often devastating disease