Exam 4: Ch 24 Flashcards
selective toxicity
Characteristic of antimicrobial drugs to exhibit a higher level of toxicity against infecting microbes than against host cells
antimicrobial drugs
Compound used primarily to treat or prevent microbial infections of the body; includes antibacterial, antifungal, antiprotozoal, and antiviral drugs
antibiotic
Compound usually but not always derived from a microorganism that inhibits the growth of other microorganisms; often encompasses synthetic compounds used for the treatment of bacterial, fungal, and protozoal diseases
bacteriostatic drug
Antibacterial medication that prevents the replication of bacteria but does not directly cause bacterial death
bactericidal drugs
Antibacterial medication that directly kills bacteria
β-lactam class
Group of antibiotics, all of which possess a β-lactam ring as a common structural feature
penicillin-binding protein (PBP)
Bacterial transpeptidase required for joining together the subunits that make up peptidoglycan of bacterial cell walls
nucleoside analog
Antiviral structural analog of nucleosides capable of inhibiting DNA or RNA synthesis by incorporation into growing nucleic acid chains by viral polymerases; prevents the addition of further nucleotides, thus interfering with viral nucleic acid replication
susceptibility testing
Controlled in vitro testing done to establish the sensitivity of a particular microorganism to various antimicrobial agents
minimal inhibitory concentration (MIC)
Lowest concentration of a drug at which no growth of the microbe being tested occurs in vitro after a standardized period of time; gives a measure of the drug susceptibility of a microbe
resistance (R) plasmid
Plasmid that confers the ability to resist antimicrobial activity of one or usually several drugs
efflux pump
Membrane protein complex used to transport various compounds, such as antimicrobial agents, directly out of the microbial cell; found naturally in many bacteria and fungi
basic reproduction number (R0)
Average number of new infections caused by an infected individual in a population of fully susceptible individuals
effective reproduction number
Number of new infections (new cases) arising from currently infected persons (existing cases) over a specific period of time during an epidemic
attack rate
Special incidence rate calculated during an outbreak and usually covering a short period of time that gives the proportion of ill individuals in an exposed population; used to estimate how many more individuals are expected to become ill
immunization
Process of generating immunological memory to prevent infection and/or disease through the introduction of antigen(s), such as microbes or their components, into the body
attenuated vaccine
Vaccine composed of a live but weakened, or less virulent, version of a microbe that is completely or nearly devoid of pathogenicity yet retains the ability to generate protective immunity in the host
inactivated vaccine
Vaccine composed of whole cells or viruses that have been physically inactivated by heat or chemical treatment yet retains the ability to generate protective immunity in the host; see also killed vaccine
killed vaccine
Vaccine composed of whole cells or viruses that have been physically inactivated by heat or chemical treatment yet retains the ability to generate protective immunity in the host; see also inactivated vaccine
subunit vaccine
Vaccine composed of one or a select number of isolated antigens; not composed of whole cells or viruses; see also acellular vaccine
nucleic acid vaccine
Vaccine composed of a cloned piece of DNA or mRNA; delivery into the cells of the body results in expression of the immunizing antigen encoded by the nucleic acid
Vaccine failure
Development of disease in individuals despite having received vaccination; usually due to the failure of certain individuals to mount an effective immune response to an immunizing agent
vaccine efficacy
Effectiveness of a vaccine measured by the average degree of protection it affords a population
herd immunity
Protection from communicable disease of non-immunized, susceptible individuals in a population by immunization of a large proportion of the rest of the population
herd immunity threshold
Critical proportion of a population required to be immunized to achieve herd immunity
vaccine coverage rate
Proportion of individuals in the population that must be immunized to achieve herd immunity
How do bacteria acquire resistance genes? Know several ways.
It is a process of natural selection facilitated through random mutations, recombination, and horizontal gene transfer.
Bacteriostatic versus bactericidal
bacteriostatic prevents replication and bactericidal kills the microbes directly
Two types of polio vaccines
Inactivated polio vaccine (IPV) and Attenuated, oral polio vaccine (OPV)
Differences in efficacy of attenuated and subunit vaccines
attenuated vaccines contain live weakened versions of a pathogen, so they can somewhat replicate without much pathogenicity and allow your adaptive immune system to memorize and destroy it easily. subunit vaccines contain one or more antigens instead of whole cells or viruses.
How do beta-lactam antibiotics work?
they inhibit peptidoglycan synthesis which is a key structural component of many bacterial cells.
Why are drugs like trimethoprim specifically toxic to bacteria and not us?
it targets enzymes and pathways that bacterial cells use that our cells don’t
