A group of scientists has carried out the largest and the deepest investigation regarding the antibiotic effects of microbes living on insects. A part of this research has discovered an antibiotic from Cyphomyrmex ant, a species from Brazil that farms fungi. This compound has been named as cyphomycin.
The lab tests have revealed that cyphomycin can fight fungi resistant to most of the antibiotics. It can also treat fungal infections in mice without exposing them to toxic effects.
The findings of this study have been discussed in a paper where scientists have discusses the ever-increasing resistance of pathogens against antibiotics.
As Many Bacteria in Insects as in Soil
A lot of antibiotics present today are derived from Streptomyces bacteria, a bug genus that evolved 400 million years ago. Over that period, these bacteria evolved and adapted itself according to different habitats such as insects and soils.
Gene studies have revealed that only one strain of this bacteria can lead to the production of tens of compound the same as those used in antibiotics. Additionally, these bacteria also have relevant biosynthetic gene sets.
Due to these reasons, scientists are studying Streptomyces in detail with a hope that it will reveal other antibiotics to combat the increasing resistance.
However, the authors of this new study have claimed that this only leads to the rediscovery of already known compounds. They also mentioned how no research has been searching for microbiomes. Hence, they chose to study the same bacteria but in a different habitat i.e. in insects.
More than 2500 different species of insects were collected by the scientists including ants, flies, bees, butterflies, moths, and beetles. Around one-third of them were taken from regions having a temperate climate while some of them came from tropics. The rest were taken from colder regions like the Arctic.
The researchers noted that contrary to the popular belief that Streptomyces is abundant in soil, it is also found in a massive amount within the insects.
Bacteria in Insects have More Power
More than 10,000 strains of bacteria were yielded by the insects. Additionally, the researchers also examined 7000 strains coming from plants and soils.
A powerful battery of tests was then performed which involved more than 50,000 trials.
The scientists then tested how every strain of the bacteria was capable of stopping the growth of 24 different types of germs, some of which could cause serious harm like MRSA.
This proved that Streptomyces derived from insects was better able to fight fungi and bacteria as compared to the strains coming from plants or soil.
In addition to this, the team also tested some other promising strains in the mice model. These strains were found to be highly effective in killing the fungal and bacterial infections. Only a few of them actually showed any toxic effects.
In a completely different part of the study, the scientists particularly focused on cyphomycin, the anti-fungal compound that they derived from Streptomyces bacteria on Brazilian Cyphomyrmex fungus-growing ant. They found that it could treat different fungal infections in mice.