Lactantes, niños, mujeres embarazadas, ancianos, pacientes con enfermedades crónicas y/o con el sistema inmune deprimido, grupos más vulnerables a las intoxicaciones alimentarias en verano

Según advierte la Sociedad Española de Endocrinología y Nutrición:

 

·         La Salmonella Enteritidis es la causa más común de intoxicación alimentaria en la Unión Europea en los meses estivales, siendo los huevos y derivados, la carne de pollo, pavo, vaca y cerdo, la leche y los helados, los alimentos más implicados        

·         Las intoxicaciones o toxiinfecciones alimentarias son enfermedades causadas por el consumo de agua o alimentos contaminados por gérmenes patógenos que, además de reproducirse, pueden producir toxinas
           

·         En la mayoría de los casos son consecuencia de un tratamiento incorrecto de los alimentos durante su obtención, trasformación, almacenamiento y preparación

·         Uno de los principales riesgos a tener en cuenta es la deshidratación, por lo que el tratamiento deberá ser una rehidratación precoz

·         Se recomienda el consumo de alimentos como el arroz, patata, zanahoria, manzana no cruda, yogur, pescado, pollo y pavo hervido

Discovery of missing links for Salmonella's weapon system

Scientists have discovered multiple gene switches in Salmonella that offer new ways to curb human infection. The discovery of the mechanisms of gene regulation could lead to the development of antibiotics to reduce the levels of disease caused by Salmonella. The breakthrough was made by Professor Jay Hinton, Stokes Professor of Microbial Pathogenesis, Trinity College Dublin and his research team and has just been published in the journal Proceedings of the National Academy of Sciences (PNAS).Salmonella causes food poisoning and kills around 400,000 people worldwide every year. The bacteria are particularly effective at causing human infection because they can survive a series of harsh conditions that kill most bacteria including strong acids in the stomach and the anaerobic and salty environment of the intestine.

"It's a decade since we discovered the Salmonella genes active during infection of mammalian cells," said Professor Hinton. "Now we have found the switches that control these critical genes. My team has gained an unprecedented view of the way that Salmonella modulates the level of the weapon systems that cause human disease."

Salmonella bacteria use a variety of proteins that act as weapons to hijack and attack human cells. Despite many decades of research throughout the world, little was understood about the way that Salmonella genes that control this weapon system are switched on. Now Professor Hinton's team has used a new approach to identify the switches of the Salmonella Typhimurium genes. The exciting new findings show that Salmonellabacteria have more than 1,800 switches, called 'promoters' and reveals how they work.

Understanding how Salmonella switches on its genes should aid the discovery of new antibiotics that will knock out the weapon systems ofSalmonella and stop the bacteria causing infection.

The researchers also identified 60 new RNA molecules, called 'small RNAs'. Some of these can actually override the switches of Salmonellagenes.

"Just five years ago, we didn't realise that small RNAs played such an important role -- or that the switches of so many Salmonella genes were controlled by small RNAs. Identifying these small RNAs could lead to completely new ways to prevent bacterial disease, but this will take at least a decade, " said Professor Hinton.

Professor Hinton's team worked in collaboration with the Wellcome Trust Sanger Institute and the University of Würzburg, and used several cutting edge techniques during the project, called chip-chip and RNA-seq. "I think one reason that our findings are making such impact is that this combination of the new technologies has not been used before for a bacterial pathogen" says lead author Dr Carsten Kröger.

Salmonella

Facts:

• Since the beginning of the 1990s, strains of Salmonella enterica sv. Typhimurium resistant to a range of antibiotics have emerged and are threatening to become a serious public health problem, particularly in developing countries.
• Symptoms of salmonellosis (food poisoning caused by Salmonella) are fever, headache, abdominal pain, diarrhea, nausea and vomiting, and are usually self-limiting after a week. In some cases, particularly in the young and very elderly, dehydration can become severe and life threatening.
• Salmonella Typhimurium can be found in a broad range of animals, birds and reptiles as well as the environment. It causes food poisoning in humans mainly through the consumption of raw or undercooked contaminated food of animal origin -- including poultry, eggs, meat, and milk, and also salad vegetables.

Science Foundation Ireland funded the research.

**Source: Trinity College Dublin

UCSB researchers find a way to detect stealthy, 'hypervirulent' Salmonella strains

A recent discovery of "hypervirulent" Salmonella bacteria has given UC Santa Barbara researchers Michael Mahan and Douglas Heithoff a means to potentially prevent food poisoning outbreaks from these particularly powerful strains. Their findings have been published in the journal PLoS Pathogens.
Salmonella is the most common cause of infection, hospitalization, and death due to foodborne illness in the U.S. This burden may continue to worsen due to the emergence of new strains that would tax current health-control efforts. To address this problem, researchers sought out -- and found -- hypervirulent strains that present a potential risk to food safety and the livestock industry.
An international team of scientists -- which also included Robert Sinsheimer and William Shimp from UCSB; Yi Xie and Bart Weimer from UC Davis; and John House from University of Sydney, Australia -- conducted a global search for hypervirulent Salmonella strains. They were found among isolates derived from livestock, and rendered current vaccines obsolete.
Bacteria behave like a Trojan Horse, exposing their weapons only after initiating infection. "These strains exhibit this behavior in the extreme -- essentially having a '5th gear' they can switch to during infection," said Heithoff, lead author of the paper.
Previous efforts to find hypervirulent strains were unsuccessful since bacteria behave much like their less-virulent cousins after environmental exposure. "The trick was to assess their virulence during infection -- before they switch back to a less-virulent state in the lab," said Professor Mahan.
Now that researchers know what to look for, they are developing methods to rapidly detect and discriminate the more harmful strains from their less-virulent cousins. The strategy is aided by a special medium utilized by the researchers that forces the bacteria to reveal their weapons in the laboratory -- the first step in the design of therapeutics to combat them.
Humans usually get Salmonella food poisoning from eating contaminated beef, chicken, or eggs. However, animal waste can contaminate fields where fruits, nuts, and vegetables are grown, thus posing a particular health concern for vegetarians. The threat is exacerbated when these foods are not cooked. Salmonella control efforts are expensive -- recent estimates place this cost up to $14.6 billion annually in the U.S.
As hypervirulent strains pose a potential risk to human and animal health, mitigation efforts warrant researchers' careful attention. "Now that we have identified the problem -- and potential solutions -- we just need to get to work," Heithoff said.

**Source: University of California - Santa Barbara