MMI133 Lecture Notes - Lecture 9: M2 Proton Channel, Amphotericin B, Polymyxin
Early Antimicrobials
● damaged host more than it did the pathogens
● Arsenic, Fever-Induction by malaria, Mercury and Penicillin
Penicillin (The Wonder Drug)
● had selective activity on prokaryotes
SULFA/Prontosil - had the 1st synthetic antimicrobial substance that works on bacteria
Parenteral - injectable
Types of Antimicrobials
1. Antiparasitic Agents (Anti-Protozoan + Helminthic Drugs) - Are quinine and derivatives to
eliminate malaria which converts the hemoglobin into toxic substance
for parasites. One
problem is the increasing resistance.
2. Antifungal Agents - Had successful agents that attacked the ergosterol
and causes
some toxicity affecting the kidneys
. The major problem is that fungi are also eukaryotes.
Amphotericin B is used for systemic fungal illness in the body.
3. Antiviral Agents (Azidothymidine/Zidovudine) - DNA/RNA synthesis inhibitors,
that can
also block attachment sites and prevent it from dissolving in M2 protein channels. Can also
inhibit enzymes used to break down DNA or RNA.
4. Antibiotic - works as a bacteriostatic (which is used with a functional immune system) or
bactericide (is used to stop the metabolism of bacteria)
Immunoactive substances may also work along with hygiene and immune integrity.
Major Classes of Antimicrobials
1. Wall synthesis inhibition (most eukaryotes do not have this
)
Cell Wall Inhibitors - Beta-Lactam include penicillin, cephalosporine, vancomycin or ampasyllin
2. Protein Synthesis inhibition
Protein Inhibitors - Macrolides (erythromycin), tetracyclines (causes teeth problems), oto
proteotoxic aminoglycosides (gentamicin)
3. Injury to plasma membrane
Cell Membrane - polymyxins (only available in topical)
4. Inhibit nucleic acid synthesis
Nucleic Acid Inhibitors - Quinolones (ciprofloxacin), rifampicin, acyclovir for Herpes, AZT and
HIV
5. Inhibit metabolites - sulfa-trimethoprim
6. Folate synthesis inhibitors (needed for the formation of DNA) - sulfides
Specific Antibiotics - inhibit gram -, + or certain bacterial species
Narrow Spectrum - used to treat a specific bacteria (e.g. penicillin
)
Broad Spectrum Antibiotics - inhibit both gram - and + bacteria
Antibiotic - a substance used to kill bacteria usually made with other bacteria
Susceptible Individuals
● diabetics
● children
● elderly
● those with a burn wound
● immunocompromised
● anyone that lacks proper hygiene
Harmful to Individuals
● who have allergies
Document Summary
Damaged host more than it did the pathogens. Arsenic, fever-induction by malaria, mercury and penicillin. Sulfa/prontosil - had the 1st synthetic antimicrobial substance that works on bacteria. Types of antimicrobials: antiparasitic agents (anti-protozoan + helminthic drugs) - are quinine and derivatives to for parasites. One eliminate malaria which converts the hemoglobin into toxic substance problem is the increasing resistance: antifungal agents - had successful agents that attacked the ergosterol and causes. The major problem is that fungi are also eukaryotes. some toxicity affecting the kidneys. Amphotericin b is used for systemic fungal illness in the body: antiviral agents (azidothymidine/zidovudine) - dna/rna synthesis inhibitors, that can also block attachment sites and prevent it from dissolving in m2 protein channels. Can also inhibit enzymes used to break down dna or rna: antibiotic - works as a bacteriostatic (which is used with a functional immune system) or bactericide (is used to stop the metabolism of bacteria)