ancient deposits. recovered scientists these loving bacteria viruses (seen with an electron microscope) from 700 year old fossilized feces.
Sandra Appelt and al./Applied and Environmental Microbiology
Petrified human excrement 14th century revealed the first evidence of an arms race in the gut human . Our gut bacteria, it seems, were using antibiotics long before people have developed drugs such as penicillin.
The bacteria that live in the intestine are territorial little suckers. When new microbes arrive, the natives fight with antibiotics. Invaders react by developing an immunity to these compounds. Thus, indigenous bacteria in your gut still known as the strongest antibiotics microbiome-develop. This war was probably carried out in the human intestine since time immemorial, but scientists had little evidence of its history.
This has now changed, thanks to a surprise find in Namur, Belgium. An urban development project, he unearthed some historical bowel movements in 1996. Excavation in a city square revealed latrines medieval buried 4 meters deep. Every location sealed barrels of human waste that has not been broadcast in nearly 700 years.
Paleomicrobiologists carefully extracted fossilized feces known as coprolites (they look a bit like rocks shaped dunette-) -From barrels to prevent bacteria and virus contamination modern medieval microbes. A deposit of feces finally plopped preserved in the laboratory of virology Christelle DESNUES the research unit on infectious and emerging tropical diseases (URMITE) in Marseille, France.
His team bored in coprolite, extract a piece of its core about the weight of a nickel. The exposed electronic microscopy structures viruslike peppery through the samples. When the team sequenced the genomes of all viruses in the old shit, they discovered that most of them were loving bacteria viruses called bacteriophages, or "phages" for short. Phages are the cargo of the bacterial world, pick up the genes from one bacterium and transfer them to another. Occasionally, this process instills their bacterial hosts with an evolutionary advantage. Indeed, the researchers found modern phage shipping antibiotic resistance genes between bacteria that cause infections, increasing their virulence.
DESNUES and his team discovered that the coprolite phage genomes were packed with antibiotic resistance genes as they online report this month in Applied and Environmental Microbiology . This confirms that the bacteriophages are an ancient reservoir of resistance genes in the intestine, which dates as far back as the Middle Ages, said DESNUES.
A greater diversity of antibiotic resistance genes have been observed in the coprolite. "It is surprising that the old stool had more [antibiotic resistance] genes that samples of modern saddles," says Jeremy Barr, a microbiologist at San Diego State University in California, who was not involved in the study. If coprolithe sample is representative of the time period, the reduction of these genes over time may reflect the modern sanitation in the food supply or water weakened bacterial defenses of intestine, he said.
Interestingly, DESNUES research team reveals that also carried metabolic genes phages that equip host bacteria with the ability to process fats and amino acids, which are the traits that made them so useful to our first intestines. the members of the human microbiome helps us digest food, inflammation of mood, and can fight against obesity, so their resistance antibiotics actually benefits us.
"It is as if we need these phages as part of our microbiome," said Vincent Racaniello, a microbiologist at Columbia University, who was not involved in the research. He said that although the intestinal phage species have changed over time, key genes they share remained the same. "We evolved as human beings at home [gut phages] for the functions they provide that is the coolest part."
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