Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
35 Cards in this Set
- Front
- Back
|
Chemotherapy
|
The use of drugs to treat a disease
|
|
|
Antimicrobial drugs
|
Interfere with the growth of microbes within a host
|
|
|
Antibiotic
|
Substance produced by a microbe that, in small amounts, inhibits another microbe
|
|
|
Selective toxicity
|
A drug that kills harmful microbes without damaging the host
|
|
|
What is Antibiotic Source of Bacitracin?
|
Bacillus subtilis
-Gram-positive rods |
|
|
What is Antibiotic Source of Streptomycin?
|
Streptomyces griseus
-Actinomycetes |
|
|
What is Antibiotic Source of penicillin?
|
Penicillium notatum
-Fungi |
|
|
Broad-spectrum:
|
both G- & G +
|
|
|
Superinfection:
|
overgrowth -or resistance
|
|
|
Bactericidal:
|
kill microbes directly
|
|
|
Bacteriostatic:
|
prevent microbes from growing
|
|
|
Inhibition of cell wall synthesis:
|
Penicillins
Cephalosporins bacitracin Vancomycin |
|
|
Inhibition of protein synthesis:
|
Chloramphenicol
Erythoromycin Tetracyclines Streptomycin |
|
|
Inhibition of nucleic acid replication and transcription:
|
Quinolones
Rifampin |
|
|
Injury to plasma membrane:
|
Polymyxin B
|
|
|
Inhibition of synthesis of metabolites:
|
Sulfanilamide
Trimethoprim |
|
|
Antibacterial Antibiotics Inhibitors of Cell Wall Synthesis
|
Penicillin
Natural penicillins: from molds Semisynthetic penicillins: ampicillin |
|
|
Antibacterial Antibiotics Inhibitors of Cell Wall Synthesis
|
Polypeptide antibiotics-
Bacitracin -Topical application -Against gram-positives Vancomycin -Glycopeptide -Important "last line" against antibiotic resistant S. aureus -MRSA |
|
|
Antibacterial Antibiotics Inhibitors of Protein Synthesis
|
Tetracyclines
-Broad spectrum --Interferes with tRNA attachment Macrolides -Gram-positives --Binds 50S, prevents translocation Erythromycin -Gram-positives --Binds 50S, prevents translocation |
|
|
Antibacterial Antibiotics Competitive Inhibitors
|
Sulfonamides (Sulfa drugs)
-Inhibit folic acid synthesis -Broad spectrum |
|
|
Sulfonamides
|
-competes with PABA for the active site of an enzyme involved in folic acid synthesis
|
|
|
Trimethoprim
|
-also interferes with production of folic acid by binding to dihydrofolate reductase (DHFR)
-DHFR is responsible for tetrahydrofolic acid production |
|
|
Acyclovir
|
replaces the origional nucleoside with a false nucleotide inhibiting DNA polymerase on Viral DNA Synthesis
|
|
|
minimal inhibitory concentration (MIC)
|
lowest concentration of drug that inhibits growth of pathogen
|
|
|
minimal lethal concentration (MLC)
|
lowest concentration of drug that kills pathogen
|
|
|
Mechanisms of Drug Resistance
|
prevent entrance of drug
-drug can’t bind to or penetrate pathogen -bacterial decrease in permeability pump drug out inactivation of drug -chemical modification of drug by pathogen alteration of target enzyme or organelle use of alternative pathways or increased production of target metabolite |
|
|
Drug resistance genes can be found on...
|
bacterial chromosomes
plasmids transposons integrons |
|
|
Origin and Spread of Resistance Genes
-chromosomal genes |
-resistance results from (rare) spontaneous mutations which usually result in a change in the drug target
|
|
|
Origin and Spread of Resistance Genes
-R plasmids |
-resistance plasmids
-can be transferred to other cells by conjugation, transduction, and transformation -can carry multiple resistance genes |
|
|
Chapter 31
|
Nonspecific (Innate) Host Resistance
|
|
|
B cells (B lymphocytes)
|
mature in bone marrow
circulate in blood can settle in lymphoid organs |
|
|
T cells (T lymphocytes)
|
mature in thymus
can remain in thymus, circulate in blood, or reside in lymphoid tissue |
|
|
null cells (includes natural killer cells)
|
kill cancer cells and cells infected with intracellular pathogens
|
|
|
Secondary Lymphoid Organ/Tissue
-spleen - |
spleen
-most highly organized lymphoid organ -filters blood -macrophages and dendritic cells trap microbes and antigens --present antigens to B and T cells ---most common way that lymphocytes become activated to carry out their immune functions |
|
|
Secondary Lymphoid Organ/Tissue
-lymph nodes- |
lymph nodes
-most highly organized lymphoid tissue -filter lymph -microbes and antigens trapped and phagocytosed by macrophages and dendritic cells -B cells differentiate into memory and plasma cells within lymph nodes |
