Cambio climático y patógenos en el agua: el fenómeno de El Niño y su impacto en la salud

Global warming induced by human activity has brought about irreversible environmental changes whose consequences are still being analyzed. Of all the affected areas, the coasts are the most volatile zones due to increasing seawater temperatures and rising sea levels. These climatic changes bring about ecological shifts, strongly impacting the biological equilibrium of coastal ecosystems. These same coastal areas are the naturally occurring habitat of the most important human pathogens of Vibrio: V. cholerae and V. parahaemolyticus. For the last year, the interaction of the oceans and climactic anomalies on the dynamics of diseases associated with these pathogens has been studied with the use of oceanographic data provided by satellites. Studies carried out in Peru using these new tools have allowed the epidemic expansion of V. cholerae and V. parahaemolyticus infections in South America to be linked to the arrival and spread of the El Niño waters. Further investigation using remote sensing data to analyze the dynamic of V. parahaemolyticus outbreaks in the USA, Spain and Chile has led to the conclusion that infections in these areas have also concurred with the presence of oceanic anomalies. The movement of oceanic waters has therefore been identified as a potential vehicle for the dispersion of Vibrio infections on a global scale, opening new channels for exploring and predicting new epidemic outbreaks of these diseases.El calentamiento global producido por la actividad humana está causando un cambio ambiental irreversible, cuyas consecuencias están siendo todavía analizadas. De todas las áreas afectadas, las regiones costeras serán de las zonas más afectadas debido al calentamiento de sus aguas y al aumento del nivel del mar. Estas alteraciones climáticas van a producir cambios ecológicos que tendrán un fuerte impacto en el equilibrio biológico de los ecosistemas costeros. Estas zonas del litoral son el hábitat natural de los dos principales patógenos humanos del género Vibrio: V. cholerae y V. parahaemolyticus. Durante los últimos años, se ha estudiado la interacción de los océanos y las anomalías climáticas en la dinámica de las enfermedades causadas por estos patógenos, utilizando la información oceanográfica aportada por los satélites. Estudios realizados en Perú, empleando estas nuevas herramientas han permitido asociar la expansión epidémica de las infecciones de V. cholera y V. parahaemolyticus en Suramérica con la llegada y propagación de las aguas de El Niño. Estudios posteriores, utilizando datos de detección remota por satélite para analizar la dinámica de los brotes de infección por V. parahaemolyticus en Estados Unidos, España y Chile, han permitido establecer que la aparición de las infecciones en estas regiones fue igualmente concurrente con la presencia de anomalías oceánicas. De esta forma, se ha identificado a los movimientos de aguas oceánicas como un motor potencial de dispersión de las infecciones de Vibrio a escala global, abriendo nuevas vías para explorar y predecir los nuevos brotes epidémicos de estas enfermedades

Future scenarios of risk of Vibrio infections in a warming planet: a global mapping study

Background: Infections caused by non-cholera Vibrio species have undergone a global expansion over the past few decades reaching new areas of the world that were previously considered adverse for these organisms. The geographical extent of the expansion has not been uniform, and some areas have shown a rapid increase in infections. Methods: We applied a new generation of models combining climate, population, and socioeconomic projections to map future scenarios of distribution and season suitability for pathogenic Vibrio. We used the Coupled Model Intercomparison Project 6 framework. Three datasets were used: Geophysical Fluid Dynamics Laboratory's CM4.0 sea surface temperature and sea surface salinity; the coastline length dataset from the World Resources Institute; and Inter-Sectoral Impact Model Intercomparison Project 2b annual global population data. Future projections were used up to the year 2100 and historical simulations from 1850 to 2014. We also project human population at risk under different shared socioeconomic pathways worldwide. Findings: Projections showed that coastal areas suitable for Vibrio could cover 38 000 km of new coastal areas by 2100 under the most unfavourable scenario with an expansion rate of season suitability in these regions of around 1 month every 30 years. Population at risk in suitable regions almost doubled from 1980 to 2020 (from 610 million to 1100 million under the scenario of medium challenges to mitigation and adaptation, shared socioeconomic pathway 2-4.5), although the increment will be more moderate in the future and stabilises after 2050 at 1300 million. Finally, we provide the first global estimate for Vibrio infections, with values around half a million of cases worldwide in 2020. Interpretation: Our projections anticipated an expansion of both the temporal and spatial disease burden for Vibrio infections, in particular at high latitudes of the northern hemisphere. However, the largest extent occurred from 1980 to 2020 and a more moderate increase is expected for the future. The most positive outcome is that the projections showed that Vibrio morbidity will remain relatively stable over the coming decades. Funding: NOAA Atlantic Oceanographic and Meteorological Laboratory and NOAA OceanWatch, and by the University of Miami's Cooperative Institute for Marine and Atmospheric StudiesS

Genome diversification within a clonal population of pandemic <i>Vibrio parahaemolyticus </i>seems to depend on the life circumstances of each individual bacteria

Artículo de publicación ISIBackground: New strains of Vibrio parahaemolyticus that cause diarrhea in humans by seafood ingestion periodically emerge through continuous evolution in the ocean. Influx and expansion in the Southern Chilean ocean of a highly clonal V. parahaemolyticus (serotype O3:K6) population from South East Asia caused one of the largest seafood-related diarrhea outbreaks in the world. Here, genomics analyses of isolates from this rapidly expanding clonal population offered an opportunity to observe the molecular evolutionary changes often obscured in more diverse populations. Results: Whole genome sequence comparison of eight independent isolates of this population from mussels or clinical cases (from different years) was performed. Differences of 1366 to 217,729 bp genome length and 13 to 164 bp single nucleotide variants (SNVs) were found. Most genomic differences corresponded to the presence of regions unique to only one or two isolates, and were probably acquired by horizontal gene transfer (HGT). Some DNA gain was chromosomal but most was in plasmids. One isolate had a large region (8,644 bp) missing, which was probably caused by excision of a prophage. Genome innovation by the presence of unique DNA, attributable to HGT from related bacteria, varied greatly among the isolates, with values of 1,366 (ten times the number of highest number of SNVs) to 217,729 (a thousand times more than the number of highest number of SNVs). Conclusions: The evolutionary forces (SNVs, HGT) acting on each isolate of the same population were found to differ to an extent that probably depended on the ecological scenario and life circumstances of each bacterium.FONDECYT 114073

Microevolution of Pandemic Vibrio parahaemolyticus Assessed by the Number of Repeat Units in Short Sequence Tandem Repeat Regions

The emergence of the pandemic strain Vibrio parahaemolyticus O3:K6 in 1996 caused a large increase of diarrhea outbreaks related to seafood consumption in Southeast Asia, and later worldwide. Isolates of this strain constitutes a clonal complex, and their effectual differentiation is possible by comparison of their variable number tandem repeats (VNTRs). The differentiation of the isolates by the differences in VNTRs will allow inferring the population dynamics and microevolution of this strain but this requires knowing the rate and mechanism of VNTRs' variation. Our study of mutants obtained after serial cultivation of clones showed that mutation rates of the six VNTRs examined are on the order of 10−4 mutant per generation and that difference increases by stepwise addition of single mutations. The single stepwise mutation (SSM) was deduced because mutants with 1, 2, 3, or more repeat unit deletions or insertions follow a geometric distribution. Plausible phylogenetic trees are obtained when, according to SSM, the genetic distance between clusters with different number of repeats is assessed by the absolute differences in repeats. Using this approach, mutants originated from different isolates of pandemic V. parahaemolyticus after serial cultivation are clustered with their parental isolates. Additionally, isolates of pandemic V. parahaemolyticus from Southeast Asia, Tokyo, and northern and southern Chile are clustered according their geographical origin. The deepest split in these four populations is observed between the Tokyo and southern Chile populations. We conclude that proper phylogenetic relations and successful tracing of pandemic V. parahaemolyticus requires measuring the differences between isolates by the absolute number of repeats in the VNTRs considered

Climate change and waterborne pathogens: the El Niño phenomenon and its impact on health Cambio climático y patógenos en el agua: el fenómeno de El Niño y su impacto en la salud

Global warming induced by human activity has brought about irreversible environmental changes whose consequences are still being analyzed. Of all the affected areas, the coasts are the most volatile zones due to increasing seawater temperatures and rising sea levels. These climatic changes bring about ecological shifts, strongly impacting the biological equilibrium of coastal ecosystems. These same coastal areas are the naturally occurring habitat of the most important human pathogens of Vibrio: V. cholerae and V. parahaemolyticus. For the last year, the interaction of the oceans and climactic anomalies on the dynamics of diseases associated with these pathogens has been studied with the use of oceanographic data provided by satellites. Studies carried out in Peru using these new tools have allowed the epidemic expansion of V. cholerae and V. parahaemolyticus infections in South America to be linked to the arrival and spread of the El Niño waters. Further investigation using remote sensing data to analyze the dynamic of V. parahaemolyticus outbreaks in the USA, Spain and Chile has led to the conclusion that infections in these areas have also concurred with the presence of oceanic anomalies. The movement of oceanic waters has therefore been identified as a potential vehicle for the dispersion of Vibrio infections on a global scale, opening new channels for exploring and predicting new epidemic outbreaks of these diseases.El calentamiento global producido por la actividad humana está causando un cambio ambiental irreversible, cuyas consecuencias están siendo todavía analizadas. De todas las áreas afectadas, las regiones costeras serán de las zonas más afectadas debido al calentamiento de sus aguas y al aumento del nivel del mar. Estas alteraciones climáticas van a producir cambios ecológicos que tendrán un fuerte impacto en el equilibrio biológico de los ecosistemas costeros. Estas zonas del litoral son el hábitat natural de los dos principales patógenos humanos del género Vibrio: V. cholerae y V. parahaemolyticus. Durante los últimos años, se ha estudiado la interacción de los océanos y las anomalías climáticas en la dinámica de las enfermedades causadas por estos patógenos, utilizando la información oceanográfica aportada por los satélites. Estudios realizados en Perú, empleando estas nuevas herramientas han permitido asociar la expansión epidémica de las infecciones de V. cholera y V. parahaemolyticus en Suramérica con la llegada y propagación de las aguas de El Niño. Estudios posteriores, utilizando datos de detección remota por satélite para analizar la dinámica de los brotes de infección por V. parahaemolyticus en Estados Unidos, España y Chile, han permitido establecer que la aparición de las infecciones en estas regiones fue igualmente concurrente con la presencia de anomalías oceánicas. De esta forma, se ha identificado a los movimientos de aguas oceánicas como un motor potencial de dispersión de las infecciones de Vibrio a escala global, abriendo nuevas vías para explorar y predecir los nuevos brotes epidémicos de estas enfermedades.</p

L'impacte negatiu de l'ésser humà sobre les pipistrel·les de vores clares

Els canvis en l'ecosistema per l'acció humana tenen impactes directes i indirectes sobre les poblacions de fauna salvatge i la seva salut. En un estudi conjunt entre el grup de recerca WildCoM de la Facultat de Veterinària, la Facultat de Genètica i Microbiologia de la UAB, l'IRTA-CReSA i el Centre Tecnològic Forestal de Catalunya, s'ha revelat l'efecte negatiu de la degradació ambiental sobre la composició i variabilitat del microbioma fecal de la pipistrel·la de vores clares.Los cambios en el ecosistema por la acción humana tienen impactos directos e indirectos sobre las poblaciones de fauna salvaje y su salud. En un estudio conjunto entre el grupo de investigación WildCoM de la Facultad de Veterinaria, la Facultad de Genética y Microbiología de la UAB, el IRTA-CReSA y el Centre Tecnològic Forestal de Catalunya, se ha revelado el efecto negativo de la degradación ambiental sobre la composición y variabilidad del microbioma fecal del murciélago de borde claro

Experiencias en la vigilancia epidemiológica de agentes patógenos transmitidos por alimentos a través de electroforesis en campo pulsado (PFGE) en el Perú

Foodborne diseases and other enteric infections often occur as outbreaks and cause morbidity and mortality all over the world. In Perú, they represent a serious public health problem, and are caused by a great variety of infectious agents. For epidemiological research, a wide array of typification methods are used. One of the most important tools for the molecular subtyping of bacterial pathogens is the Pulsed Field Gel Electrophoresis (PFGE), which is a highly precise method that allows the discrimination between different bacterial isolates which are epidemiologically related. The Instituto Nacional de Salud del Perú (INS) is part of the WHO Global Foodborne Infections Network (WHO-GFN) and of the PulseNet Latin American and Caribbean Net (PN-AL C), with whom it shares the genetic profiles of the isolated pathogenic strains, so that it is possible to compare de genotypes of similar strains found in different countries and to identify the occurrence of epidemic outbreaks in the region, strengthening the regional system of epidemiological surveillance and generating a rapid, coordinated response between the countries. We present the two last years´ experience including the advances in the use of these strategic tools that have allowed us to characterize genotype patterns implicated in foodborne diseases from isolates recovered in the laboratory network of Peru.Las enfermedades transmitidas por alimentos (ETA) y otras enfermedades entéricas infecciosas ocurren a menudo como brotes y son causa de morbilidad y mortalidad en todo el mundo. En el Perú, son un importante problema de salud pública y son causados por una gran variedad de agentes infecciosos. Para la investigación epidemiológica se utiliza una variedad de métodos de tipificación. Una de las herramientas más importantes en la subtipificación molecular de patógenos bacterianos es la técnica de la electroforesis en campo pulsado (PFGE), que es un método altamente resolutivo que permite la discriminación entre diferentes aislamientos bacterianos epidemiológicamente relacionados. El Instituto Nacional de Salud (INS) del Perú integra las redes WHO Global Foodborne Infections Network y la Red PulseNet América Latina y Caribe, con quienes comparte los perfiles genéticos de las cepas patógenas aisladas, permitiendo comparar los genotipos de cepas semejantes halladas en diferentes países y reconocer la ocurrencia de brotes epidémicos en la región, fortaleciendo el sistema de vigilancia epidemiológica regional y generando una rápida respuesta conjunta entre países. Se presenta la experiencia de los dos últimos años sobre los avances en la utilización de estas herramientas estratégicas que nos ha permitido caracterizar patrones de genotipo de principales patógenos implicados en ETA a partir de aislamientos recuperados de la red de laboratorios del Perú

Epidemiology of Vibrio parahaemolyticus Outbreaks, Southern Chile

Disease outbreaks caused by Vibrio parahaemolyticus in Puerto Montt, Chile, began in 2004 and reached a peak in 2005 at 3,600 clinical cases. Until 2006, every analyzed case was caused by the serovar O3:K6 pandemic strain. In the summer of 2007, only 475 cases were reported; 73% corresponded to the pandemic strain. This decrease was associated with a change in serotype of many pandemic isolates to O3:K59 and the emergence of new clinical strains. One of these strains, associated with 11% of the cases, was genotypically different from the pandemic strain but contained genes that were identical to those found on its pathogenicity island. These findings suggest that pathogenicity-related genes were laterally transferred from the pandemic strain to one of the different V. parahaemolyticus groups comprising the diverse and shifting bacterial population in shellfish in this region

Frequency of observed and expected mutants according to a geometric distribution, with 1, 2, 3, or 4 repeat unit changes for each of the clones examined.

<p>The expected frequency of mutants according to geometric distribution is shown in bold italics.</p