When salmonella infect the gut, the body reacts with immune cells, the macrophages, which ingest bacteria. But sometimes these macrophages come out of the intestine carrying salmonella. An electrical phenomenon caused by the bacteria would explain this change of direction of the macrophages.
The characteristics of salmonella
They are Gram-negative bacilli, … "data-image =" https://en.cdn.v5.futura-sciences.com/buildsv6/images/midioriginal/a/e/5/ae581faf88_50035980_salmonella-dr-01 .jpg "data-url =" / health / definitions / medecine-salmonella-7912 / "data-more =" Read more "> are that cause many . According to a statement on the they would cause 400,000 deaths worldwide each year. These deaths are often due to the fact that bacteria leave the gut thanks to immune cells: macrophage structure
A macrophage is a cell of blood origin, which comes from the transformation of the monocyte.
It is located in tissues that can be subjected to infections or a build up of debris to be eliminated … "data-image =" https://en.cdn.v5.futura-sciences.com/buildsv6/images/midioriginal /5/8/0/58076b6647_50034174_macrophage-obli-wiki-cc.jpg "data-url =" / health / definitions / medecine-macrophage-190 / "data-more =" Read more "> .
In the intestine, if bacteriaare present, Like macrophages or cell biology, a neutrophilic body is a cell body that has an affinity for neutral dyes: cations like … "data-image =" https: //fr.cdn.v5.futura- sciences.com/buildsv6/images/midioriginal/e/b/a/ebab9cc881_50035458_tomate-neutrophile-gertrud-k-cc-nc-2.jpg "data-url =" / planet / definitions / botanical-neutrophil-6805 / "data -more = "Read more"> are attracted to the site of infection by molecular signals: this phenomenon is called . The macrophages will then "eat" the bacteria, that is to say swallow and digest them by . But sometimes, instead of remaining in the intestine, these macrophages pass into the blood, which has the effect of spreading the bacteria in the body and aggravate the infection. Some bacteria survive in macrophages and use it as a means of transport to reach other organs.
On the surface of the intestine, small electric field is a concept that dates back to the work of Coulomb (1785), this is the force field associated with a unit electric charge. It derives from the electric potential.
The … "data-url =" / sciences / definitions / field-electric-field-3880 / "data-more =" Read more "> , generated by the tissues, serve to direct cells that move, like macrophages, by the mechanism of "electrotaxis" or "galvanotaxis". Also, electrical modifications of the macrophage environment can change their cellular?
In this study published in
The cecum is a pocket corresponding to the first part of the colon, following the ileum of the small intestine. The ileocecal valve regulates the entry of the food bolus into the cecum, which … "data-image =" https://en.cdn.v5.futura-sciences.com/buildsv6/images/midioriginal/e/ 0/9 / f09c6318f5_50034384_caecum-dr.jpg "data-url =" / health / definitions / biology-cecum-2210 / "data-more =" Read more "> of the mouse. They have shown that infection with Salmonella alters the electrical minifield of the , which attracts macrophages.
An electric field that impacts macrophage migration
In the experiments, the infection generated a small electric field at the tissue composed of juxtaposed cells arranged in one or more layers lining the internal surface of the organs. Most tumors originate from epithelial cells (see carcinoma). "Data-url =" / health / definitions / medecine-epithelium-2100 / "data-more =" Read the definition ">intestinal, which directed the macrophages towards the Attention, the term anode does not … "data-image =" https://fr.cdn.v5.futura-sciences.com/buildsv6/images/midioriginal/3/ 0/7 / 307697abed_128236_anode-pile.jpg "data-url =" / sciences / definitions / chemistry-anode-331 / "data-more =" Read more "> , the positive pole of the electric field. But in vitroonce the macrophages have ingested , they are attracted by the Attention, the term … "data-image =" https://fr.cdn.v5.futura-sciences.com/buildsv6/images/midioriginal/0/4/4/044c0a47d5_128247_cathode-pile .jpg "data-url =" / sciences / definitions / chemistry-cathode-332 / "data-more =" Read more "> : their sense of migration is reversed!
It is therefore a mode of heterotrophic nutrition in which other organisms or detritus are ingested, whole or in pieces.
Ingesting is therefore also a … "data-image =" https://fr.cdn.v5.futura-sciences.com/buildsv6/images/midioriginal/d/e/0/de03e1e416_50035452_ingestion-aspiration-james- gathany-centers-disease-control-prevention-public-domain.jpg "data-url =" / health / definitions / biology-ingestion-6793 / "data-more =" Read more "> bacteria by phagocytosis would reverse galvanotaxis. This change is related to Protein Roles
Proteins can perform a variety of functions within the cell or organism.
They may have:
a structural role (such as actin or tubulin which … "data-image =" https://fr.cdn.v5.futura-sciences.com/buildsv6/images/midioriginal/4/6/e/46e94f9da7_50034188_actine -thomas-splettstoesser-cc.jpg "data-url =" / health / definitions / biology-protein-237 / "data-more =" Read more "> charged on the surface of . In a pictorial way, it is a little as if the bacteria actuated an electrical switch which modifies the direction of migration of the macrophages.
The authors conclude: "We propose that macrophages be attracted to the site of infection by a combination of chemotaxis and galvanotaxis; after phagocytosis of the bacteria, the surface electrical properties of the macrophage change and the galvanotaxis moves the cells away from the site of the infection. " We can imagine that this electrical change leads macrophages to migrate out of the intestine.
This discovery could help scientists find ways to prevent food poisoning from becoming serious, says Alex Mogilner, one of the authors of this study: "The Sciences of Matter
Action to spread in order to reach a uniform state; result of this action. In the case of light, reference in all directions to … "data-image =" https://www.cdn.v5.futura-sciences.com/buildsv6/images/midioriginal/4/6/ 8 / 4686984e83_50034253_reflexion-diffuse-en.jpg "data-more =" / sciences / definitions / physics-diffusion-1020 / "data-more =" Read more "> , rather than localized infection, is the leading cause of death due to Salmonella (and other foodborne bacteria). Therefore, better understanding this change in polarity will likely help to develop new treatments to reduce the number of foodborne bacterial infections. "
What you must remember
- Salmonella is a bacterium responsible for food poisoning.
- When bacteria leave the intestine, transported by macrophages, the infection gets worse and can lead to death.
- Researchers show that ingestion of bacteria by macrophages causes electrical changes that impact the direction taken by macrophages.