Antibiotics are widely considered one of the most important advances in the history of medicine. Their introduction into clinical practice during the 1940s marked a major milestone in the control of infectious diseases, and these medicines have since improved human health and prolonged life expectancy.

Today, bacterial resistance to antibiotics has become a global threat, and presents a major challenge to medicine. Antibiotics’ extensive and often indiscriminate use in medicine, veterinary clinics and agriculture has created the ideal conditions for antibiotic-resistant bacteria to emerge.

However, this phenomenon is older than previously thought. Bacteria already had resistance mechanisms long before the discovery and introduction of antibiotics into clinical practice. This indicates that antibiotic resistance is a much more complex, widespread and deep-rooted ancestral evolutionary phenomenon than initially assumed.

Studies have documented antibiotic resistance mechanisms in micro-organisms isolated from natural habitats, where human influence is minimal or non-existent. These environments include deep underground layers and the ocean floor, as well........

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