Micro: Ch 28 Vaccines and Antimicrobial Drugs

antigen

foreign that triggers an immune response and antibody production

vaccine

preparation of antigens that stimulates protective immunity without causing disease

vaccination/immunization

introduction of a vaccine into the body to generate active immunity and immune memory

booster shot

an additional vaccine dose that enhances/restores immune protection over time

SARS-CoV-2 spike protein importance

acts as the antigen targeted by vaccines to trigger immune response

herd immunity

large portion of a population is immune, reducing disease spread and protecting susceptible individuals

why do highly infectious diseases need higher herd immunity?

they spread more easily, so more individuals must be immune to break transmission chains

antimicrobial drugs

compounds used to treat infections by killing or inhibiting pathogens within the body

antibiotics vs. synthetics

• antibiotics are naturally produced by microbes

• synthetics are chemically made

semi-synthetic drugs

natural antibiotics that have been chemically modified to improve effectiveness

selective toxicity

ability of a drug to target pathogens without harming host cells

therapeutic dose vs. toxic dose

• therapeutic dose is effective treatment level

• toxic dose is the level that causes harmful side effects

why is therapeutic index important?

ratio of toxic dose to therapeutic dose; higher index = safer drug

narrow vs. broad spectrum drugs

• narrow targets a few pathogens

• broad affects many types, including normal microbia

side effects of antimicrobials

damage to host cells or normal microbia (yeast infections)

quinolones

inhibit DNA replication by targeting DNA gyrase/topoisomerase

macrolides

bind to 50S ribosomal subunit and inhibit protein synthesis

tetracyclines

bind to 30S ribosomal subunit and block protein synthesis

B-lactam antibiotics

inhibit cell wall synthesis and causes bacterial cell lysis

gram + bacteria are ___

more affected by penicillin because they have thicker peptidoglycan layers targeted by B-lactams

antimicrobial resistance

ability of microbes to survive exposure to drugs that would normally kill them

resistance spreading

horizontal gene transfer (transformation, conjugation, transduction)

efflux pumps

transports proteins that expel antibiotics from bacterial cells

how do mutations contribute to resistance?

random genetic changes can make microbes less susceptible to drugs

preventing resistance

use antibiotics only when necessary, complete full course, use narrow-spectrum when possible

future strategies against resistance

development of new drugs and alternative therapies (ex: phage therapy)