what does e coli do to your body
The bacterium Escherichia coli, commonly known as Eastward. coli, has a duplicitous reputation. Scientists tell us that near strains of the microbe live peacefully in our guts or the guts of other mammals, munching on bits of food, causing no harm or even creating benefits for their hosts.
But the grotesque imagery of E. coli infections tells a different story: After eating food contaminated with pathogenic strains, people tin can experience airsickness, diarrhea, and dysentery. And in rare cases, the bacteria can lead to kidney failure and even expiry.
Ken Campellone, assistant professor of molecular and cell biology in the College of Liberal Arts and Sciences, wants to understand how these bacteria can play such different roles. By focusing on the interactions betwixt 1 of the deadliest E. coli strains and the cells of the homo gut, he'southward learning not only how the leaner works, simply how our ain cells work, too.
Recently, Campellone discovered a item poly peptide in the cells of the human large intestine that is taken over past E. coli cells and helps to bind the bacterium to the abdominal wall.
"Pathogens accept establish really clever ways of taking over the normal processes of our cells," he says. "Often they know more about our own cells than we do, and information technology's actually intriguing."
The strain of Eastward. coli that Campellone studies belongs to a group of the bacteria called enterohemorrhagic E. coli, or EHEC, that oft makes international news when people swallow contaminated meat or vegetables. In 2011, an outbreak of a hemorrhagic strain in Deutschland infected more than 3,700 people, killing 45. The Centers for Disease Control and Prevention estimate that about 75,000 infections occur each year in the United states of america.
The reason for this high level of virulence, says Campellone, is a serial of genetic acquisitions past the harmful bacteria. Scientists have sequenced several types of E. coli, and they've constitute more than than 1,000 genes in the harmful group that are not nowadays in the harmless, or commensal, grouping.
Simply, he adds, of the roughly ane,000 genes that have been identified as pathogenic, relatively few accept been characterized.
"We know very petty virtually the genes in EHEC that are different from the commensal version," he says. "My goal is to ameliorate understand how a group of genes that encode proteins called effectors take over their homo cell targets."
In particular, the most unsafe types have caused the genes to produce a poisonous substance called Shiga toxin, which Campellone says can produce an affliction ranging from unpleasant to life-threatening.
"If the toxin is just released into your intestines, yous would get diarrhea and dysentery," he says. "But if it enters your bloodstream, it tin can cause serious kidney damage and become fatal." Plus, he adds, there are currently no known medicines for the blood poisoning syndrome, and antibiotics only make the symptoms worse. Patients simply have to wait and promise.
Campellone's research focuses on how the trafficking and organization of proteins command the shape of cells. When E. coli affix themselves to the intestinal wall, they disrupt its normal organisation. They exercise this past delivering bacterial proteins into the cell, which in plough recruit specific intestinal jail cell proteins that unremarkably shape the prison cell.
In 2004, Campellone was the first to identify a protein that the E. coli injects into the intestinal cells, causing the product of a fleshy bulge that lifts the attached bacteria away from the wall. Scientists call this lump a "pedestal" – because it really does look like 1 – but they still aren't sure what its purpose is.
Campellone also recently discovered a protein in human intestinal cells that interacts with the bacterial poly peptide to help create the pedestal. He published these results in the June 2012 issue of The Periodical of Biological Chemistry.
The discovery is significant considering if a drug was developed that could block the pedestal from being produced, then the E. coli might not be able to stick to the intestinal wall, he explains. In that example, the bacteria might simply wash through a person'due south system, causing little harm.
In the classroom and in his laboratory, Campellone says these examples from his inquiry give his students real-life examples of the data they larn about prison cell structure.
"When nosotros teach cell biology, we show students that a lot of what we know most how man cells normally function is from studying infections," he says, pointing out that many cellular proteins have only been discovered in the context of pathogens trying to exploit them.
"Being able to ask scientific questions experimentally in the laboratory then become an answer that could benefit people – that'southward the most exciting office for the students, and for me," he says. "You lot tin can be the first person in the world to know something."
Source: https://today.uconn.edu/2012/07/how-e-coli-cells-work-in-the-human-gut/
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