With courtesy of Alexander Wild / University of Wisconsin
No one likes a cockroach in their house. But before you break the unwanted intruder, think about it: this six legs can one day save your life.
That's right. Insects, long known for the spread of diseases, can help with their treatment. Or rather, the microbes living inside them could. Scientists have discovered dozens of microorganisms living in or on insects that produce antimicrobial compounds, some of which may have the key to developing new antibiotic drugs. More infections become resistant to the usual antibiotics, and the pipeline of new antibiotic preparations slows to a thin trickle. DeGroote Institute for Research on Infectious Diseases at McMaster University
Most antibiotic drugs are found by bacteria living in the soil. But Cameron Curie, a professor of bacteriology at the University of Wisconsin-Madison, says soil demand for new antibiotics is becoming more and more meaningless. "They continue to find already known antibiotics," Curie says. "There is a common opinion that the well of antibiotics from the soil … is dry."
Fortunately, there may be another well. Currie and a team of 28 researchers recently published a report in Nature Communications which shows that some of the bacteria living in insects are really good at killing germs that make people sick. "There are about 10 million species [of insect] on the planet," says Curie. "This implies a huge potential for many new compounds."
Each insect contains an entire ecosystem of microorganisms, just like a microbiome found in humans. There is also a quality that many of these insect microbes have in common, says Jonathan Klassen, Molecular and Cell Biology Assistant at the University of Connecticut and the author of the study.
And by not understanding, it means they are constantly trying to kill each other through biochemical warfare. Many insect microorganisms make compounds that are toxic to other microbes – essentially, natural antibiotics. Some of these natural antibiotics attract Curie's attention while he was a student examining leaf ants. the most prolific gardeners in nature. They do not actually eat the leaves they cut – instead they use them to cultivate a special type of fungus for food. However, it is not easy to be a fungus farmer.
"Like human farming, ants have problems with disease," says Curie. "I found a specialized pathogen that attacks their garden."
Fortunately, the ants have a tool to deal with the problem. A type of bacteria living in ants exoskeleton produces a toxin that kills the pathogen. Like the pesticides the gardener uses, the toxin preserves the anthrax garden diseases.
The discovery inspired the curiosity of Carrie. If ants can use these bacterial compounds to treat diseases in their fungi, can doctors use them to treat human diseases? If so, what other insects can also carry germs fighting disease? To answer these questions, Kerry and his team have spent years collecting thousands of insects, including cockroaches, from Alaska to Brazil. he would have gone out to collect something, "recalls Klassen, who at that time worked as a PhD student on the project. The team investigates bacteria from each insect to determine whether they can kill common human pathogens such as E. coli and Staphylococcus aureus (MRSA) resistant to methicillin . They then compare the results from strains of insect bacteria to plant and soil derived strains.
"We were really surprised that [insect strains] was not that good, but apparently better in inhibition [pathogens]," says Kerry. 19659008] Once a scientist has discovered that a strain of bacteria can kill germs, the next step in drug development is to determine what bacterial compound is responsible for antimicrobial activity – as
Currie's team has found dozens of promising bacterial strains in insects. And anyone can bring a secret ingredient, which may be a new antibiotic compound. This in itself was a great achievement. But the researchers went one step further. They isolate a compound from a particularly promising bacterial strain and show that it can inhibit fungal infections in mice, which is an important step in the development of the drug. The compound, cyfomycin, is found in Brazilian ants cultivating mushrooms, close relatives of Curie ants, studied as a PhD student. Although this is far from becoming an approved drug, studies have shown that antibiotic compounds, new to science, can be isolated from insects. Wright, an antibiotic investigator who did not participate in the study, says previous research has shown that individual insect types containing antimicrobial compounds. But this is the first study that fully demonstrates that insects as a group are a promising source of new antimicrobials.
"No one has ever done anything on this scale," Wright explains.
Carey hopes that cyfomycin may be approved for treating human yeast infections. But before that happens, he must undergo years of further testing.  "He's a million miles [from approval]," says Wright. "This is the reality of the discovery of drugs."
However, Wright says that researchers have already overcome one of the most difficult hurdles in drug development by demonstrating that the compound works in mice.
For Klassen, bets are too high, "Efforts like this study are crucial to keeping the ongoing antibiotic pipeline so the disease does not prevail," he says.
In the end, the consequences of a world without antibiotics are
Paul Chisholm is a freelance writer in Rapid City, SD You can contact him on Twitter: @PaulJChisholm .