Scientists have long known that antibiotic resistance is a natural evolution through both natural selection of random mutations beneficial for bacteria, and evolutionary stresses on a population that force change. It is only now though, that they are learning about when some of the world’s worst superbugs came into existence.

Staphylococcus aureus for example, was one of the first major resistant pathogens and became resistant to penicillin in 1947, just four years after the drug began being mass-produced.

Recently researchers from the Harvard Medical School discovered that Enterococci emerged on Earth 450 million years ago—long before dinosaurs.

Adaptation to the harsh environment

Have superbugs always existed or are they a new phenomenon?
Have superbugs always existed or are they a new phenomenon?

Researchers have found that Enterococci inhabited the gut of animals that are now extinct. According to the study, new species of Enterococci appeared as new types of animals emerged, including after mass extinctions such as the End Permian Extinction that occurred 251 million years ago.

They also show that the traits that now facilitate the survival and transmission of these ''superbugs'' in the hospital environment.

The traits that aided in facilitating the current survival and transmission of superbugs appears to be a selective advantage in the harsh conditions of the Palaeozoic era. The pathogens began to evolve, becoming naturally resistant to dryness and starvation.

“Life on land would have selected for the precise traits that now allow pathogenic enterococci to survive desiccation, starvation, and disinfection in the modern hospital, foreordaining their emergence as leading hospital pathogens,” the authors wrote.

Now these characteristics allow them to survive in modern day hospitals—protecting them against disinfectants and a variety of antibiotics.

Global war with superbugs

Superbugs are becoming a much larger problem now because of two human-caused evolutionary stresses: unnecessary prescription and incorrect diagnosis and adding antibiotics to food for livestock for growth promotion.

Antibiotics as food additives in livestock feed began in 1950 in New York and this discovery coupled with innovations in mass production, made the drugs cheaper than traditional supplements. Today, more than 630,000,00 kilograms of antibiotics are used for this purpose the world over. This is particularly disturbing since some of the world’s most deadly human diseases in history have originated in animals.

Unfortunately, change in this is very difficult as it can severally impact farmer’s livelihoods, especially in the developing world. If trends continue, by 2050, it is expected that 10 million people globally, will die each year from antibiotic resistant conditions.

In developing countries, generally diagnostic technologies are not up to standard and doctors feel obliged to provide some sort of medication.

Otto Cars, founder of an organisation which campaigns for action on antimicrobial resistance, says, “Imagine you’re a doctor in rural India faced with a mother and a feverish child.”

“You have to give them a really broad spectrum antibiotic but you’re groping around in the dark and that’s why so many of these drugs have rapidly become useless in these countries,” he explains.

In the developed nations, they are overprescribed and studies show that patients expect both medication and to recover from illnesses faster than it actually takes.

New approach to tackling superbugs

It has been almost 30 years since the last new class of antibiotics was discovered in 1987 because the easiest way to discover drugs in soil, plants and water have already been found. Unfortunately, screening plants and insects is an incredibly time-consuming process with no guarantee of success and big pharmaceutical companies are reluctant to fund.

The new study investigating the evolutionary history of superbugs may be a new perspective in finding the solution to the deadly pathogens.

“These are now targets for our research to design new types of antibiotics and disinfectants that specifically eliminate enterococci, to remove them as threats to hospitalised patients,” concluded Francois Lebreton, one of the authors of the study. MIMS

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