What is AMR?
The challenges of antimicrobial resistance (AMR) have a long history that dates back to the development of penicillin. In Alexander Fleming’s speech accepting the 1945 Nobel Prize in Physiology or Medicine for his discovery of penicillin in 1928, he said:
"The time may come when penicillin can be bought by anyone in the shops. Then there is the danger that the ignorant man may easily underdose himself and by exposing his microbes to non-lethal quantities of the drug make them resistant."
In fact, an enzyme which inactivates penicillin named penicillinase had been discovered from penicillin-resistant bacteria in 1940, five years before the speech was given. True to Fleming’s prediction, the post-war history of the rapid development of antibiotics can be described as the history of warfare waged against AMR. In the 1960s, as effective antibiotics against penicillin-resistant bacteria were developed one after another, including methicillin for Staphylococcus aureus, and aminopenicillin (ampicillin) and aminoglycosides (gentamicin) for Gram-negative bacteria, people gradually began to believe that bacterial infections could be defeated.
With powerful weapons to fight against infectious diseases, such as vaccines and antibiotics, the leading cause of death in developed countries has shifted from infectious diseases to non-communicable diseases (NCDs), and so did the pharmaceutical trends. The development of new antimicrobials has steadily declined since the 1980s. Meanwhile, the threat by new antimicrobial-resistant bacteria began to rise predominantly in hospital settings. It was the emergence of healthcare-associated infections (HAIs) associated with surgery and medical devices developed through the advancement of medical technologies.
These HAIs spread also in Japan, caused by antimicrobial-resistant Gram-positive cocci including Methicillin-resistant Staphylococcus aureus (MRSA), Vancomycin Resistant Enterococci (VRE), followed by antimicrobial-resistant Gram-negative bacilli including multidrug-resistant Pseudomonas aeruginosa (MDRP) and multidrug-resistant Acinetobacter spp. (MDRA). It remains as a significant problem in medical institutions to the present day. While initially associated with medical institutions, this growing problem is now increasingly found outside the healthcare settings, called community-acquired antimicrobial-resistant infections.
Regarding AMR issue in animals, the development of antimicrobial-resistant bacteria in animals could reduce the efficacy of medical treatment for animals. In addition, it has been indicated that antimicrobial-resistant bacteria of animal origin have a potential to be transmitted to and cause infectious diseases in humans through livestock products, and consequently reduce the efficacy of antibiotics in humans.
Outside Japan, the rise of AMR is not confined to general bacterial infections. Malaria parasites have become resistant to artesunate, a drug known as a specific medicine against malaria. In addition, multidrug-resistant and extremely drug-resistant tuberculosis (acid-fast bacterium) has spread around the world.
The Jim O’Neill report which attempted to calculate the number of death as well as the cost in terms of lost global production due to AMR between now and 2050 would become an extremely disturbing 10 million every year which are more than those of cancer at present, and an enormous 100 trillion USD all over the world, respectively, if we do not take action. Today, as the progress of globalization, we cannot ignore AMR issue as something unrelated to us, and the countermeasure for AMR is recognized as the challenge facing countries around the world.