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.

  • Resistance and Resistivity

    • Resistance and resistivity describe the extent to which an object or material impedes the flow of electric current.
    • Conductance and resistance are reciprocals .
    • What determines resistivity?
    • Its resistance to the flow of current is similar to the resistance posed by a pipe to fluid flow.
    • Identify properties of the material that are described by the resistance and resistivity

  • Resistance to French Rule

  • Dependence of Resistance on Temperature

    • Resistivity and resistance depend on temperature with the dependence being linear for small temperature changes and nonlinear for large.
    • The resistivity of all materials depends on temperature.
    • where ρ0 is the original resistivity and α is the temperature coefficient of resistivity.
    • is the temperature dependence of the resistance of an object, where R0 is the original resistance and R is the resistance after a temperature change T.
    • Compare temperature dependence of resistivity and resistance for large and small temperature changes

  • 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

  • Factors Affecting Pulmonary Ventilation: Airway Resistance

    • Airway resistance refers to resistance in the respiratory tract to airflow.
    • Airway resistance can change over time, especially during an asthma attack when the airways constricts causing an increase in airway resistance.
    • Below is the equation for calculating airway resistance (R).
    • Therefore the resistance to air in the bronchi is greater than the resistance to air in the trachea.
    • Laminar flow (a) has orderly layers and low resistance.