BackMicrobiology Exam 3 Key Concepts
Terms in this set (20)
An attenuated vaccine is a live pathogen weakened by mutations in virulence genes so it no longer causes disease but can still replicate and stimulate immunity.
Naturally acquired immunity develops after exposure to a pathogen without medical intervention, while artificially acquired immunity is induced intentionally by vaccines or medical treatments.
Variolation was the deliberate inoculation of healthy people with material from smallpox lesions to induce immunity.
Agglutination involves antibodies cross-linking antigens on large insoluble particles producing visible clumps; precipitation involves antibodies cross-linking small soluble antigens into an insoluble lattice that precipitates out of solution.
A monoclonal antibody is produced by clones of a single B cell and recognizes a single epitope on an antigen.
An immunoassay is a lab test using antibodies that bind specific antigens to detect or measure target molecules in a sample.
An inactivated vaccine contains pathogens chemically or physically altered so they cannot replicate, preventing infection amplification but still presenting antigenic structures.
They inhibit penicillin-binding proteins that form peptide cross-links in peptidoglycan, causing un-cross-linked cell walls and osmotic lysis of growing bacteria.
Because bacteria have a peptidoglycan cell wall and 70S ribosomes (30S and 50S subunits) which differ from human cells.
Antibiotic resistance is a genetic trait making drugs less effective; antibiotic use selects for pre-existing resistant cells, increasing their frequency.
A superinfection is a secondary infection during or after antimicrobial therapy due to removal of susceptible normal microbes, allowing resistant organisms to proliferate.
A broad-spectrum drug is toxic to a wide variety of bacteria, including both Gram-positive and Gram-negative species.
Because fungi are eukaryotes sharing many cellular structures and pathways with human cells, limiting unique drug targets.
Polypeptide antibiotics disrupt earlier steps of peptidoglycan synthesis and lack a beta-lactam ring; beta-lactams contain a beta-lactam ring and inhibit transpeptidation by binding PBPs.
The therapeutic window is the dosage range between the minimum effective dose and the minimum toxic dose where a drug is effective and safe.
They bind and inhibit bacterial replication or transcription enzymes that differ structurally from human equivalents.
Antiviral drugs target viral processes or structures with minimal harm to host cells.
The MIC is the lowest antibiotic concentration that prevents visible growth of a bacterium in vitro.
Bacterial ribosomes are 70S with 30S and 50S subunits, structurally different from eukaryotic 80S ribosomes, enabling selective targeting.
Synergism: combined effect greater than expected from each drug alone; Antagonism: combined effect less than expected from each drug alone.