Antimicrobial Resistance (AMR) and Antibacterial Resistance (ABR)
A major public health concern is the development of antimicrobial resistance (AMR) in pathogenic bacteria, which is likely to lead to worsened sickness, higher death, and increased treatment costs with constrained treatment alternatives. The AMR Review from 2014 predicted that if this issue is not addressed, there will be much more deaths than the expected 10 million per year by the year 2050.
Antimicrobial resistance is the capacity of microorganisms to fend off the effects of drugs that, in the past, would have killed them or prevented their growth. Microbes can continue to grow even after being exposed to antimicrobial agents thanks to the development of antimicrobial resistance. The length of time it takes to recover from an illness, the severity of the sickness, the amount of treatment required, and the potential fatality risk all rise if pathogens acquire resistance.
Studies and observations of AMR in bacteria and fungus are more frequent. A small number of parasites have also evolved resistance to their available treatments. Antibacterial resistance (ABR) is the term used when bacteria become resistant to “antibiotics”. Antifungal resistance (AFR) is the term used to describe a fungus’ development of resistance to “antifungals”. The development of resistance by viruses and helminths against their respective treatments is referred to as “antiviral resistance” and “anthelmintic resistance,” respectively.
The most significant form of AMR is antibacterial resistance (ABR), which has been linked to major infections through the development of resistance in many pathogenic bacterial species. Although it is less common than bacterial resistance, resistance in fungi, viruses, and parasites is also becoming more often reported.
Four AMR mechanisms in general cause the development of AMR
- Possibility of altering or inactivating the medication
- Decrease in medication affinity or absorption
- An increase in drug efflux
- Changing the cellular components that are the drug’s target spot
These mechanisms either originate as a result of gene insertions or mutations that affect any of these systems. Microbes may only be resistant to one type of antibiotic or they may be resistant to several. If the resistance is limited to one class of antimicrobials that are structurally and mechanistically similar or identical, it is simply referred to as that class of resistance. For instance, a bacterium is simply referred to as a “penicillin-resistant bacteria” if it is resistant to penicillin and its derivatives.
Resistance to numerous antimicrobials with distinct structures and modes of action is referred to as multi-drug resistance (MDR). A popular definition is that an antibiotic is an MDR if it is resistant to at least “one antimicrobial in three or more categories” of structurally unrelated antimicrobials. MDR pathogens are known as the “SUPER BUGS.” Additional categories for MDR include extensively drug-resistant (XDR) and universally drug-resistant (PDR). Antibiotics from no more than two antibiotic classes that are structurally unrelated will be effective against XDR infections. The PDR pathogens will be immune to all antimicrobials.
AMR has been listed as one of the top 10 global public health hazards by the World Health Organization (WHO). In a paper titled “Global priority list of antibiotic-resistant bacteria to guide research, discovery, and Development of novel antibiotics,” the WHO published a list of pathogens in 2017. In its 2019 AR Threat Report, the US Centers for Disease Control and Prevention (CDC) published a list of resistant bacteria and fungi. In addition to pathogens of concern in the US, this list also contains microorganisms from the WHO’s 2017 list.
