Traveller's diarrhoea by Vibrio cholerae in patients returning from the Dominican Republic / Diarrea del viajero por Vibrio cholerae en pacientes que regresan de República Dominicana

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Emergence, ecology and dispersal of the pandemic generating Vibrio cholerae lineage

Although cholera is an ancient disease that first arose at least half a millennium ago, it remains a major health threat globally. Its pandemic form is caused by strains from a single lineage of the bacterium Vibrio cholerae. The ancestor of this lineage harbored several distinctive characteristics, the most notable being the O1 antigen polysaccharide. This lineage generated two biotypes, first Classical, responsible for six pandemics, and later El Tor, responsible for the seventh and ongoing pandemic. Just as El Tor replaced Classical as the main cause of outbreaks in the last fifty years, several variants of El Tor have evolved and displaced their predecessors worldwide. Understanding the ecology, evolution and dispersal of pandemic V. cholerae is central to studying this complex disease with environmental reservoirs. Here, we present recent advancements of our knowledge on the emergence and spread of the pandemic generating lineage of V. cholerae in the light of established eco-evolutionary observations. Specific ecological interactions shape seasonal cholera, playing a role in the abundance and distribution of its causative agent. Both species-specific and lineage-specific genetic determinants play a role in the ability of V. cholerae strains to cause pandemics with seasonal outbreaks, having evolved gradually over centuries. On the basis of the current understanding, we outline future threats and changes in biogeographical and genomic-based investigation strategies to combat this global problema (AU)

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Mechanisms of the evolutionary arms race between Vibrio cholerae and Vibriophage clinical isolates

This review highlights recent findings on the evolutionary arms race between the causative agent of cholera Vibrio cholerae and virulent bacteriophages (phages) ICP1, ICP2, and ICP3 isolated from cholera patient stool samples. We discuss mechanisms of phage resistance such as a unique phage-inhibitory chromosomal island and mutations that affect phage receptor expression. We also discuss the molecular characterization of ICP1 and its unique CRISPR-Cas system, which it uses to combat the phage-inhibitory chromosomal island. The role of phages in the life cycle of V. cholerae has been increasingly recognized and investigated in the past decade. This article will review hypotheses as to how the predator-prey relationship may have an impact on infections within individuals and on the self-limiting nature of cholera epidemics. In addition, we put forth a strategy of using phages as an intervention to reduce household transmission of cholera within a community (AU)

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Coordination between replication, segregation and cell division in multi-chromosomal bacteria: lessons from Vibrio cholera

Bacteria display a highly flexible cell cycle in which cell division can be temporally disconnected from the replication/segregation cycle of their genome. The accuracy of genetic transmission is enforced by restricting the assembly of the cell division apparatus to the low DNA-density zones that develop between the regularly spaced nucleoids originating from the concurrent replication and segregation of genomic DNA. In most bacteria, the process is simplified because the genome is encoded on a single chromosome. This is notably the case in Escherichia coli, the most well studied bacterial model organism. However, ~10% of bacteria have domesticated horizontally acquired mega-plasmids into extra-numerous chromosomes. Most of our current knowledge on the cell cycle regulation of multi-chromosomal species derives from the study of replication, segregation and cell division in Vibrio cholerae, the agent of the deadly epidemic human diarrheal disease cholera. A nicety of this model is that it is closely related to E. coli in the phylogenetic tree of bacteria. Here, we review recent findings on the V. cholerae cell cycle in the context of what was previously known on the E. coli cell cycle (AU)

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T6SS intraspecific competition orchestrates Vibrio cholerae genotypic diversity

Vibrio cholerae is a diverse species that inhabits a wide range of environments from copepods in brackish water to the intestines of humans. In order to remain competitive, V. cholerae uses the versatile type-VI secretion system (T6SS) to secrete anti-prokaryotic and anti-eukaryotic effectors. In addition to competing with other bacterial species, V. cholerae strains also compete with one another. Some strains are able to coexist, and are referred to as belonging to the same compatibility group. Challenged by diverse competitors in various environments, different V. choleare strains secrete different combination of effectors - presumably to best suit their niche. Interestingly, all pandemic V. cholerae strains encode the same three effectors. In addition to the diversity displayed in the encoded effectors, the regulation of V. cholerae also differs between strains. Two main layers of regulation appear to exist. One strategy connects T6SS activity with behavior that is suited to fighting eukaryotic cells, while the other is linked with natural competence - the ability of the bacterium to acquire and incorporate extracellular DNA. This relationship between bacterial killing and natural competence is potentially a source of diversification for V. cholerae as it has been shown to incorporate the DNA of cells recently killed through T6SS activity. It is through this process that we hypothesize the transfer of virulence factors, including T6SS effector modules, to happen. Switching of T6SS effectors has the potential to change the range of competitors V. cholerae can kill and to newly define which strains V. cholerae can co-exist with, two important parameters for survival in diverse environments (AU)

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Genomic Plasticity of Vibrio cholerae

Vibrio cholerae is one of the deadliest pathogens in the history of humankind. It is the causative agent of cholera, a disease characterized by a profuse and watery diarrhoea that still today causes 95.000 deaths worldwide every year. V. cholerae is a free living marine organism that interacts with and infects a variety of organisms, from amoeba to humans, including insects and crustaceans. The complexity of the lifestyle and ecology of V. cholerae suggests a high genetic and phenotypic plasticity. In this review, we will focus on two peculiar genomic features that enhance genetic plasticity in this bacterium: the division of its genome in two different chromosomes and the presence of the superintegron, a gene capture device that acts as a large, low-cost memory of adaptive functions, allowing V. cholerae to adapt rapidly (AU)

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Divergent functional roles of D-amino acids secreted by Vibrio cholera

The L-forms of amino acids are used in all kingdoms of life to synthesize proteins. However, the bacterium Vibrio cholerae, the causative agent of cholera, produces D-amino acids which are released to the environment at millimolar concentrations. We baptized these D-amino acids as non-canonical D-amino acids (NCDAAs) since they are different from those (i.e. D-alanine and D-glutamate) normally present in the bacterial cell wall. In V. cholerae, production of NCDAAs relies on the BsrV enzyme, a periplasmic broad spectrum racemase. BsrV multispecific activity, produces of a wide range of distinct D-amino acids. Using a combination of genetics and molecular physiology approaches we have demonstrated that NCDAAs target different cellular processes which may function as part of a cooperative strategy in vibrio communities to protect non-producing members from competing bacteria. Because NCDAA production is widespread in bacteria, we anticipate that NCDAAs are relevant modulators of microbial subpopulations in diverse ecosystems (AU)

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Bacteriemia por Vibrio cholerae no toxigénico: los riesgos del consumo de marisco en un paciente cirrótico / Bacteraemia due to non-toxigenic Vibrio cholerae: The risks of eating seafood in a cirrhotic patient

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Bacteriemia por Vibrio cholerae no O1 y no O139 en un paciente Portugués con cirrosis y no viajero: informe de caso / Vibrio cholerae non-O1 and non-O139 bacteremia in a non-traveler Portuguese cirrhotic patient: First case report

La bacteriemia por Vibrio cholerae no-O1 y no-O139 es una enfermedad rara y potencialmente mortal. Presentamos un caso de bacteriemia por Vibrio cholerae no-O1 y no-O139 en un hombre portugués con cirrosis debida a Hepatitis C que fue ingresado por diarrea aguda tras el consumo de gambas. No había viajado recientemente. Según nuestro conocimiento, este es el primer caso de bacteriemia por Vibrio cholerae no O1 y no O139 acaecido en Portugal (AU)

Bacteremia due to Vibrio cholerae non-O1 and non-O139 is a rare condition and potentially fatal. We report a case of bacteremia due to V. cholerae non-O1 and non-O139 in a Portuguese male with Hepatitis C cirrhosis, admitted due to acute diarrhea, after consuming shrimp. He had no recent travels. To our knowledge, this is the first reported case of bacteremia due to V. cholerae non-O1 and non-O139 in Portugal (AU)

El cólera en Haití: llover sobre mojado / Cholera in Haiti: it never rains but it pours

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Estudio comparativo de la actividad antibacteriana in vitro de los neumatóforos de Heritiera fomes y Xylocarpus moluccensis / A comparative study on the in vitro antibacterial activity of the pneumatophores of Heritiera fomes and Xylocarpus moluccensis

Se evaluó la actividad antibacteriana in vitro de los extractos de etanol de los neumatóforos de Xylocarpus moluccensis (Familia: Meliaceae) y Heritiera fomes (Familia: Sterculiaceae) frente a diversas cepas bacterianas utilizando el ensayo de difusión en disco. Ambos extractos presentaron perfiles antibacterianos similares, y las zonas de inhibición fueron >10 mm en la mayoría de los casos. Estos extractos presentaron la máxima actividad frente a aerógenos Enterobacter, siendo las zonas de inhibición de 19 y 21 mm, respectivamente. La concentración inhibitoria mínima(CIM) se determinó mediante el método de dilución en caldo de cultivo. El extracto de X. moluccensis fue el más potente frente a Shigella boydii y Shigella sonnie (CIM = 200 y 300 mg/mL, respectivamente). Se puede asumirque X. moluccensis y H. fomes podrían ser fuentes potenciales de nuevos descubrimientos para el desarrollo de fármacos (AU)

The ethanol extracts of the pneumatophores of Xylocarpus moluccensis (Family: Meliaceae) and Heritiera fomes (Family: Sterculiaceae) were assessed for in vitro antibacterial activities against a number of bacterial strains using the disc diffusion assay. Both extracts showed similar antibacterial profiles, and the zones of inhibitions were >10 mm in the most cases. These extracts exhibited the most prominent activity against Enterobacter aerogenes, with the zones of inhibition of 19 and 21 mm, respectively. The minimum inhibitory concentration (MIC) was determined by the broth dilution method. The extract of X. moluccensis was the most potent against Shigella boydii and Shigella sonnie (MIC = 200 and 300 mg/mL, respectively). It can be assumed that that X. moluccensis and H. fomes could be potential sources for novel ‘lead’ discovery for antibacterial drug development (AU)

El cólera / No disponible

El cólera es una enfermedad diarreica transmisible protagonista de 7 importantes pandemias a lo largo de la historia y que, hoy en día, está totalmente controlada en los países desarrollados gracias a la gran mejoría de las condiciones higiénico-sanitarias. A pesar de ello, sigue siendo causante de miles de muertes cada año en los países más desfavorecidos del planeta. La bacteria Vibrio cholerae, responsable de esta patología, se transmite a través del agua/alimentos contaminados y cuando es capaz de invadir el intestino humano secreta una toxina causante de cuadros de diarrea que pueden llegar a ser muy severos, y, en caso de retraso/falta de tratamiento, acabar con la vida del afectado. Sus reservorios habituales son la persona contaminada y el agua. Las estrategias de control de la transmisión de la enfermedad son sencillas y sobradamente conocidas. El abastecimiento de agua limpia y su correcta depuración, junto con las prácticas higiénicas básicas en el tratamiento de los alimentos, pueden evitar la aparición de la enfermedad. Tristemente, estas condiciones no se cumplen en los países más pobres y los esfuerzos dedicados al desarrollo de una vacuna preventiva son muy grandes. De las tres vacunas disponibles actualmente, destacamos la vacuna oral de células muertas enriquecida con parte de la toxina, que ha demostrado ser altamente eficaz y segura. El papel de la immunización es importante en el control de la enfermedad, tanto en áreas endémicas como en zonas con riesgo de epidemia. Los viajeros de alto riesgo son también candidatos a vacunación (AU)

Cholera is a transmissible diarrheal disease the cause of 7important pandemics throughout history which in the present day is completely controlled in developed countries thanks to the greatly improved hygienic sanitary conditions. In spite of this it is still the cause of thousands of deaths every year in the most disadvantaged countries of the planet. The bacteria Vibrio cholerae, the cause of this pathology, is transmitted by means of contaminated food and water and when it is able to invade the human intestine it secretesa toxin causing bouts of diarrhoea which can become extremely severe and, in the case of delay/lack of treatment, can cause the death of the affected person. Its usual reservoirs are the contaminated person and water. The transmission control strategies of the disease are simple and only too well known. The provision of clean water and its correct purification together with basic hygienic practices in the treatment of food can avoid the appearance of the disease. Sadly, these conditions are not fulfilled in the poorer countries and the efforts dedicated to the development of a preventive vaccine aregreat. Of the three available vaccines at present, we highlight the oral vaccine of dead cells enriched with part of the toxin, which has shown to be highly efficient and safe. The role of immunization is important in the control of the disease, both in endemic areas and zones with risk of epidemic. High risk travellers are also candidates for vaccination (AU)

Infectious disease and environment: cholera as aparadigm for waterborne disease

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Sepsis por Vibrio cholerae no-01 en paciente inmunodeprimida / Septicemia caused by vibrio cholerae non-01 in immunocompromised patient

Describimos el caso poco frecuente de una paciente con una sepsis por Vibrio Cholerae no 0-1 asociado a lesiones cutáneas en extremidades inferiores y superiores. Esta paciente padecía de una hepatopatía crónica y un carcinoma de cérvix en estadío IIIB y había sido ingresada el día previo por una descompensación ascítica. Su evolución fue buena con resolución completa mediante cefotaxima endovenosa. Destacar sobre todo el hallazgo de su origen epidemiológico, aguas continentales de pozos naturales, siendo esta particularidad la que hace de este caso el primero descrito en España con ese origen demostrado y un caso excepcional en la literatura mundial revisada (AU)

Otitis media supurada por vibrio cólera tipo no-01 / Suppurative otitis media by non-01 Vibrio cholera

El vibrio cholerae tipo no-01 es un microorganismo de distribución mundial con hábitat acuático, que ocasionalmente produce patología en el hombre. Existe relación directa demostrada entre la ingesta de productos de mar y/o la realización de actividades marinas, y la infección por vibrio. La clínica que produce con más frecuencia es la gastrointestinal y en particular la enfermedad diarreica. Por otro lado, la otitis media por vibrio cholerae tipo no01 es extremadamente infrecuente en nuestro medio, aunque si se revisa la bibliografía, su incidencia parece haber aumentado durante los últimos años. Se presenta un caso clínico de otitis media supurada por vibrio cholerae tipo no-01 y se revisa la literatura. (AU)

Bacteriemia por Vibrio cholerae no 01. A propósito de dos casos / Bacteremia by Vibrio cholerae no 01. Two cases

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