Tag: insects

Categories : Antibiotics Diseases, Syndromes and ConditionsTags :

Insects Carry a Range of Antimicrobial-resistant Bacteria

On By ModernMedia

A study published in Nature Microbiology has for the first time provided compelling evidence of connections between antimicrobial-resistant bacteria causing surgical-site infections and insects and other arthropods. Among these bacteria are those with resistance to drug-of-last-resort. 

Antimicrobial resistance (AMR) could render many of the current mainstay and last-resort antibiotics useless, resulting in many more deaths from previously treatable infections. A UN report estimated in 2019 that AMR could lead to ten million deaths per year, and cost the world $100 trillion, by 2050.

“Similar to our experience over the last eighteen months with the pandemic, a problem currently seen from afar will quickly come into focus much closer to home” said Professor Tim Walsh at Oxford University

The report found that:

  • About 20% of the flies, cockroaches, spiders, moths, and ants were carrying carbapenem resistance.
  • Of these, 70-80% were carrying extended spectrum cephalosporin resistance, that is, enzymes that confer resistance to most beta-lactam antibiotics, including penicillins, cephalosporins, and the monobactam aztreonam.
  • Currently there are about 18 million flies to every human, but conservative global warming projections estimate insect and fly population will double if temperatures increase by 1.5 degrees.
  • By 2080 there could be around 50 000 trillion flies carrying carbapenem resistance and spreading AMR across the planet.

“Similar to our experience over the last eighteen months with the pandemic, a problem currently seen from afar will quickly come into focus much closer to home,” said Prof Walsh. “The clinical burden of AMR is most felt in low-middle income countries, but the increase in global temperatures, due to climate change, will result in a significant increase in flies and many other insects and a subsequent increase in the global velocity of antibiotic resistance.” Prof. Tim Walsh, Oxford University.

AMR is a pervasive issue, stretching from hospitals to farming and human waste processing. Resistance can spread within hospitals, communities, farms, and wastewater systems, and domestic animals can share AMR microorganisms with humans.

One tactic is to repurpose previously developed drugs that did not work for humans and use these for animals, buying time for us to develop new drugs.

Another is to rethink hospital prevention and infection control measures, especially in lower- and middle-income countries. Further research into how arthropods disseminate AMR and improving healthcare infrastructure to reduce the spread of AMR by arthropods.

“Most antibiotics currently used on animals are also the same that are used in humans, creating a pool where bacteria can evolve to evade drugs and then reinfect humans,” said Prof Tim Walsh of Oxford University.

“There is no silver bullet when it comes to tackling the worldwide threat of AMR,” he added. “The Ineos Oxford Institute for AMR Research is committed to finding non-human antibiotic therapies and feeds for animals, addressing the increase in AMR in human infections and raising awareness of this hidden threat to human health. But this is a global medical crisis that ultimately will only be resolved with a global response.”

Source: Oxford University

Categories : New Compounds and TreatmentsTags :

Antifungal Compound Discovered in Ant Farms

On By ModernMedia

Researchers in Brazil have discovered an antifungal compound by bacteria living in ant farms, which may have medical applications.

In the fungal farms where attine ants tend as their food source, Pseudonocardia and Streptomyces bacteria produce metabolites which shield the crop against pathogens. Curiously, these metabolites vary across geographic locations.

Attine ants are a type of ant which grow and harvest fungus for food, and are only found in the Western Hemisphere. They first evolved from a common Amazonian ancestor some 50 million years ago, giving rise to some 200 species of ants spread across South and Central America, which share common farming practices. The bacteria at these farms have a symbiotic relationship where they defend against fungi such as Escovopsis in exchange for food.

These metabolites vary considerably, suggesting a fragmented history. Searching a number of ant nests spread across a large geographical area, the researchers discovered that two thirds of the Pseudonocardia strains were producing the same metabolite. They named this newly discovered metabolite attinimicin.The study was the first one where a common, specialised metabolite produced by ant-associated bacteria was found across geographic locations.

Attinimicin inhibited fungal parasites while not harming the fungal crop, but only in the presence of iron. It proved as effective in treating Candida albicans infections in mice as a clinically used azole-containing antifungal. This means that the metabolite could have clinical applications. Attinimicin was shown to have a similar structure to two other metabolites produced by Streptomyces, suggesting the responsible genes have a common evolutionary origin.

Source: News-Medical.Net

Journal information: Fukuda, T.T.H., et al. (2021) Specialized Metabolites Reveal Evolutionary History and Geographic Dispersion of a Multilateral Symbiosis. ACS Central Science. doi.org/10.1021/acscentsci.0c00978.