multidrug resistance

(noun)

A condition enabling a disease-causing organism to resist distinct drugs or chemicals of a wide variety of structure and function targeted at eradicating the organism.

Examples of multidrug resistance in the following topics:

  • Cost and Prevention of Resistance

    • Antimicrobial resistance is a major public health and economic burden on patients, affected communities, and healthcare providers.
    • Patients who are infected with bacterial strains resistant to more than one type or class of drugs (multidrug-resistant organisms, MDRO) often have an increased risk of prolonged illness, extended hospital stay, and mortality.
    • Multidrug resistance forces healthcare providers to use antibiotics that are more expensive or more toxic to the patient.
    • Research and development of new drugs effective against resistant bacterial strains also comes at a cost.
    • Antibiotic misuse is a major cause of the staggering healthcare costs for the treatment of resistant bacterial strains.

  • Biofilms, Persisters, and Antibiotic Tolerance

    • Persisters are multidrug tolerant cells present in all bacterial populations.
    • Biofilms and persisters are the cause of multidrug tolerance.
    • Multidrug tolerance differs from multidrug resistance in that it is not caused by mutant microbes but rather by microbial cells that exist in a transient, dormant state.
    • Explain the role of biofilms and persisters in multidrug tolerance, distinguishing this from multidrug resistance

  • Antimicrobial Peptides

    • AMPs have proven effective against multidrug-resistant microbes.

  • Microorganisms in the Hospital

    • Such infections include fungal and bacterial infections, and are aggravated by the reduced resistance of individual patients.
    • Methicillin-resistant Staphylococcus aureus (MRSA) is a bacterium responsible for several difficult-to-treat infections in humans .
    • It is also called multidrug-resistant Staphylococcus aureus and oxacillin-resistant Staphylococcus aureus (ORSA).
    • Strains unable to resist these antibiotics are classified as methicillin-sensitive Staphylococcus aureus, or MSSA.
    • The development of such resistance does not cause the organism to be more intrinsically virulent than strains of Staphylococcus aureus that have no antibiotic resistance, but resistance does make MRSA infection more difficult to treat with standard types of antibiotics, and thus more dangerous.

  • Antimycobacterial Antibiotics

    • For treatment of leprosy, caused by Mycobacterium leprae, the traditional antimycobacterial drugs include promin (the first treatment introduced to fight leprosy) and dapsone (which eventually become obsolete as Mycobacterium leprae quickly evolved resistance).
    • Modern drugs which were developed in response to the resistance was clofazimine and rifampicin.
    • The use of multidrug therapies including dapsone, clofazimine and rifampicin were advantageous due to the low risk of antibiotic resistance.
    • However, the use of these multidrug treatments was costly and only adopted in endemic countries when the World Health Assembly passed a resolution to eliminate leprosy in 1991.

  • Mechanisms of Resistance

    • Resistance can be mediated by the environment or the microorganism itself .
    • Intrinsic resistance is considered to be a natural and inherited property with high predictability.
    • Once the identity of the organism is known, the aspects of its anti-microbial resistance are also recognized.
    • On the other hand, acquired resistance results from a change in the organism's genetic makeup.
    • Describe the mechanisms bacteria use to develop antimicrobial resistance and the factors that can lead to it

  • Relative Resistance of Microbes

    • Endospores are considered the most resistant structure of microbes .
    • They are resistant to most agents that would normally kill the vegetative cells from which they formed.
    • Certain bacterial species are more resistant to treatment than others.
    • Gram-negative bacteria have high natural resistance to some antibiotics.
    • Staphylococcus aureus is one of the major resistant pathogens.

  • Antibiotic Misuse

    • Antibiotic misuse is one factor responsible for the emergence of antimicrobial resistant bacterial strains.
    • Antibiotic resistance occurs when antibiotics no longer work against disease-causing bacteria.
    • Some resistant infections can even cause death.
    • Antibiotic misuse has contributed largely to the emergence of new resistant strains.
    • Misusing them leads to resistant bacterial strains.

  • Finding New Antimicrobial Drugs

    • Antimicrobial resistance has created a public health crisis in the treatment of infectious diseases and necessitates the discovery of new drugs.
    • Research on new antimicrobial compounds is geared towards innovative targets to circumvent resistance.
    • It is also necessary to initiate a worldwide awareness on antibiotic misuse and overuse as a mean to address the root of the problem for antimicrobial resistance.
    • most bacterial species listed in this figure have developed resistance to available antibiotics necessitating new drug discovery.
    • Explain the reasons for low production of new antibiotics and discuss the proposed mechanisms to evade antimicrobial resistance

  • Deinococcus and Thermus

    • The Deinococcus-Thermus are a small group of bacteria composed of cocci highly resistant to environmental hazards.
    • The Deinococcus-Thermus are a small group of bacteria composed of cocci that are highly-resistant to environmental hazards.
    • The Thermales include several genera resistant to heat (Marinithermus, Meiothermus, Oceanithermus, Thermus, Vulcanithermus).
    • Though these two groups evolved from a common ancestor, the two mechanisms of resistance appear to be largely independent.
    • It is extremely resistant to ionizing radiation, ultraviolet light, desiccation, and oxidizing and electrophilic agents.