History of Antimicrobials

The introduction of antibiotics into clinical practice marked a transformative moment in the treatment and management of infectious diseases (Aminov, 2017). These powerful agents have significantly improved global health outcomes by drastically reducing morbidity and mortality rates associated with infections such as pneumonia, and tuberculosis (Aminov, 2017; Cook & Wright, 2022). Before the advent of antibiotics, infectious diseases were responsible for over half of all deaths (Cook & Wright, 2022). Antimicrobials, encompassing antibiotics, antifungals, antivirals, and antiparasitics, are essential in treating infections by either inhibiting the growth of or killing the pathogens responsible. The term ‘antibiotic’ was first coined by Selman Waksman to describe any small molecule produced by a microbe that could inhibit the growth of other microorganisms (Ribeiro da Cunha et al., 2019).

The first antimicrobial agent introduced globally was salvarsan, developed by Ehrlich in 1910 as a treatment for syphilis. In 1935, Domagk and his colleagues advanced the field by developing sulfonamides, synthetic compounds that, despite their groundbreaking nature, were limited by safety and efficacy concerns (Saga & Yamaguchi, 2009). The discovery of the first true antibiotic came serendipitously in 1928 when Alexander Fleming observed that the growth of Staphylococcus aureus was inhibited around a contaminated blue mold (a fungus from the Penicillium genus) in his culture dishes. This observation led to the realization that microorganisms could produce substances capable of inhibiting the growth of other microorganisms (Saga & Yamaguchi, 2009; Aminov, 2017). However, the initial use of penicillin in clinical practice faced significant challenges due to issues like low yield, instability, and difficulties in purification (Aminov, 2017). Despite these early hurdles, penicillin became a lifesaving treatment in the 1940s, notably saving the lives of many wounded soldiers during World War II (Saga & Yamaguchi, 2009; Aminov, 2017).

Educational Video: The Accidental Discovery of Antibiotics

Source: TED-ED

The discovery of new antimicrobials is not satisfactory compared to the increased rates of AMR pathogens (Bisi-Johnson et al., 2017). During the last 40 years, a limited number of new antibiotics have been licensed (Bloom et al., 2018). The World Health Organisation notes that of the 11 antibiotics approved since 2017, only 2 represent a novel class of antibiotics. The rest are derivatives of already existing antibiotics, which raises concerns that resistance to those drugs will quickly develop and render them ineffective. Many of these new drugs show little distinct benefit over current drugs and are more expensive. Pharmaceutical companies are afraid of not making a profit before the emergence of resistance to any antimicrobial put on the market, resulting in a nearly dry pipeline for new drugs (Cook & Wright, 2022). It is known that resistance to a given antimicrobial emerges in less than ten years after its introduction to the market (Blair et al., 2015). However, this period may go to even less than five years if the new drug is overused. 

Image: Antibiotics Discovery timeline

Source: Khan Academy

Timeline of the discovery of different antibiotic classes in clinical use. “The discovery void” refers to the period from 1987 until today, as the last antibiotic class that has been successfully introduced as treatment was discovered in 1987.

Due to the AMR pandemic, new control measures are urgently needed to counter their long-term consequences (Rosini et al., 2020). In Sub-Saharan Africa (SSA), there is a paucity of drug discovery centers highlighting the need to establish and equip them for a safe future of the sub-continent (Amewu et al., 2022).