antimicrobial resistance

Examples of antimicrobial resistance in the following topics:

• Mechanisms of Resistance

  • Development of microbial resistance to antimicrobial agents requires alterations in the microbe's cell physiology and structure.
  • An example of antimicrobial resistance mediated by anaerobic atmosphere is the shutdown of bacterial protein synthesis by aminoglycosides.
  • Development of microbial resistance to antimicrobial agents requires alterations in the microbe's cell physiology and structure.
  • Some common pathways bacteria use to effect antimicrobial resistance include: enzymatic degradation or modification of the antimicrobial agent, decreased uptake or accumulation of the antimicrobial agent, altered antimicrobial target, circumvention of consequences of antimicrobial actions, uncoupling of antimicrobial agent-target interaction, or any combination of these mechanisms.
  • Describe the mechanisms bacteria use to develop antimicrobial resistance and the factors that can lead to it

• 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.
  • Some of the proposed areas to investigate include: collecting and examining the list of antimicrobial resistance genes (e.g. exploring the resistome), targeting teichoic acid biosynthesis as a new method to compromise the bacterial wall integrity, producing ribosomal inhibitors to target protein synthesis, targeting outer-membrane transporters with protein epitope mimetics (e.g. mimetics of the cationic antimicrobial peptides that form part of the immune response to microbes), and developing antibody-based strategies and vaccines.
  • 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.
  • Explain the reasons for low production of new antibiotics and discuss the proposed mechanisms to evade antimicrobial resistance

• 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.
  • To prevent antimicrobial resistance, the patient and the healthcare provider should discuss the appropriate medicine for the illness .

• Antibiotic Misuse

  • Antibiotic misuse is one factor responsible for the emergence of antimicrobial resistant bacterial strains.
  • Some resistant infections can even cause death.
  • Antibiotic misuse has contributed largely to the emergence of new resistant strains.
  • Scientists say antimicrobial resistance may be passing between animals and humans through food consumption, making the need to cut unnecessary use of antibiotics in farming even more urgent.
  • Misusing them leads to resistant bacterial strains.

• Antimicrobial Proteins

  • Antimicrobial peptides are a unique and diverse group of molecules.
  • Bacteria can develop resistance to antimicrobial peptides (as well as separate resistances to antibiotics and other antimicriobials).
  • Bacteria like staphylococcus aureas, which forms the highly resistant MRSA strain, can reduce the negativity of the charge of its cell membrane by bringing amino acids from the cytoplasm into its cell membrane so antimicrobial peptides won't bind to it.
  • Other forms of antimicrobial resistance include producing enzymes that inhibit the antimicrobial peptides, altering the hydrophobic forces on the cell membrane, and capturing antimicrobial peptides in vesicles on the cell membrane to remove them from the bacterium.
  • Additionally, commensal bacteria have developed antimicrobial resistance to peptides , but they are normal flora of the body.

• Synthetic Antimicrobial Drugs

  • Disinfectants are antimicrobial substances used on non-living objects or outside the body.
  • Antimicrobials include not just antibiotics, but synthetically formed compounds as well.
  • However, with the development of antimicrobials, microorganisms have adapted and become resistant to previous antimicrobial agents.
  • The old antimicrobial technology was based either on poisons or heavy metals, which may not have killed the microbe completely, allowing the microbe to survive, change, and become resistant to the poisons and/or heavy metals.
  • Recall the synthetic antimicrobial drugs that are sulfonamide and sulphonamide based

• Antimicrobial Peptides

  • In contrast to the clonal, acquired adaptive immunity, endogenous peptide antibiotics or antimicrobial peptides provide a fast and energy-effective mechanism as front-line defense.
  • Antimicrobial peptides (AMPs) are small molecular weight proteins with broad spectrum antimicrobial activity against bacteria, viruses, and fungi.
  • AMPs have proven effective against multidrug-resistant microbes.
  • In addition to important antimicrobial properties, growing evidence indicates that AMPs alter the host immune response through receptor-dependent interactions.

• Naturally Occurring Antimicrobial Drugs: Antibiotics

  • Disinfectants are antimicrobial substances used on non-living objects or outside the body.
  • Now, most of these infections can be cured easily with a short course of antimicrobials.
  • However, with the development of antimicrobials, microorganisms have adapted and become resistant to previous antimicrobial agents.
  • This allowed the microbe to survive, change, and become resistant to the poisons and/or heavy metals.
  • Discuss the mechanism of action for protein synthesis inhibitors used as antimicrobial drugs, and recognize various naturally occuring antimicrobial drugs

• Biological Control of Microbes

  • A wide variety of chemicals called antimicrobial agents are available for controlling the growth of microbes.
  • No single antimicrobial agent is most effective for use in all situations - different situations may call for different agents.
  • Additional variables to consider in the selection of an antimicrobial agent include pH, solubility, toxicity, organic material present, and cost.
  • Modern studies suggest that the use of biological control in the treatment of human infections should be re-evaluated in the light of the increasing world-wide occurrence of antibiotic-resistant bacteria, and the opportunities provided by recent developments in gene technology.
  • Describe the types of antimicrobial agents available for controlling the growth of microbes

• Antimicrobial Peptides

  • Antimicrobial peptides are an evolutionarily conserved component of the innate immune response and are found among all classes of life.
  • Antimicrobial peptides have been demonstrated to kill Gram negative and Gram positive bacteria (including strains that are resistant to conventional antibiotics), mycobacteria (including Mycobacterium tuberculosis), enveloped viruses, fungi and even transformed or cancerous cells.
  • Antimicrobial peptides generally consist of between 12 and 50 amino acids.
  • This amphipathicity of the antimicrobial peptides allows the partition of the membrane lipid bilayer.
  • Several methods have been used to determine the mechanisms of antimicrobial peptide activity.