Salmonella continues to show signs
A group of researchers from the IBR , discovered that a particular type of fatty acids present in the content of the human diet , they act as inhibitory signals involved in the invasion process bacteria Salmonella enterica in the body infected .
The finding opens the door for the design of new drugs to combat this important pathogen associated with human infections caused by the contamination of food, water and contact with pets. In addition to their potential application in human medicine, the researchers propose a model by which a biological sensor present in the plasma membrane of S. enterica recognizes signals that optimize their adaptation to different habitats in the gastrointestinal tract. This ecological adaptation allow virulence factors , synthesized by S. enterica and neutralize the defenses of the infected organism, are produced in poor cellular compartments fatty acids, thus promoting their survival and dissemination.
The working group led by Eleonora Garcia Vescovi, CONICET researcher , Institute of Molecular and Cellular Biology of Rosario (IBR-CONICET-UNR) together with the group led by Ricardo L. Furlan , Department of Pharmacognosy , the Faculty of Pharmacy and Biochemistry (UNR) , was recently published in the Journal of Biological Chemistry and highlighted by the editor in ” ScienceSignaling ” .
According to estimates by the World Health Organization , each year about 21 million people infected with Salmonella, of which between 200,000 to 600,000 recorded in the world are fatal cases. So, interpreting how bacteria colonize achieved , survive and multiply evading the defenses of the infected organism is a very competitive area of global research, since there is no specific treatment or effective vaccine to treat salmonellosis .
Development and Strategy
” In addition to the result itself , the interesting development of this work was the strategy , how did to find it . Ricardo Furlan , PhD in Chemistry and a researcher of CONICET , provided us with a collection of extracts from plant compounds , and together, we designed a tracking methodology that allowed us to easily detect whether or not the compounds have biological activity on this system turn on or off the program Salmonella virulence. One of the key molecules identified in these experiments was linoleic acid, an essential fatty acid for the human body , “says Garcia Vescovi .
As in almost every discovery , on the way toward the ultimate goal , is where new data appear , marking a break and redirect research.
This was the case of Garcia Vescovi and Furlan, who in the screening of natural compounds and chemically modified with the intention of extending the functional diversity of the same , by incorporating new activities , so to find a compound that serves as a drug , found a naturally occurring molecule that Salmonella detect it passes into the body to which infects . Therefore, this is a discovery of interest to the scientific community, due to the large impact that knowledge of the mechanisms used Salmonella to develop the disease.
The model proposes that Salmonella is able to ” feel” through ” sensing apparatus ” unsaturated fatty acids of the external environment and in response to this, the bacteria reacts and reprograms the expression of their genes, underlines the researcher, who over 20 years ago is bound to unravel the mechanisms that make a pathogenic bacterium Salmonella .
He adds , “We know that Salmonella enter through the mouth by contaminated water or food , and we speculate that once in the gastro -intestinal tract unsaturated fatty acid found in the bacteria when it makes contact with the biliary content , and into the intestine . Reaffirming this idea, there is a demonstrated association between gallstones and the chronic carrier state of Salmonella, this implies that the bacteria remains in the medium of bile. We continue studying to determine which physiological media Salmonella is unsaturated fatty acids . ”
Globally, the emergence of strains of Salmonella multi-resistant to antibiotics has increased the need to identify and / or develop new antimicrobial compounds with different targets of action to those currently used .
According to Diego de Mendoza, CONICET researcher , specialist in the subject , “This work represents an example illustrating the interaction of researchers using complementary experimental strategies such as combinatorial chemistry and molecular biology, is very powerful for discovering new molecules involved in the mechanism of infection of pathogenic organisms to man. This enhances the importance of this research , because it could lead to the discovery of new antibiotics. ”
Moreover, from these results, the research also delves deeper into the mechanistic description of characteristics, since the molecular basis of how the bacterial “detector” interacts specifically recognizing fatty acid is studied. “Getting the molecular basis for designing new elements would molecules with pharmacological potential and manages the master key that the virulence of the bacteria. Regarding the methodology of tracking new antimicrobial molecules , this study has been the initial tip – foot : we have so far is a proof of principle of the strategy, scalable , easy to automate or robotizar oriented search compounds with a target for Salmonella and applicable to other pathogens”, concludes the researcher.