medical microbiology Flashcards
Medical Microbiology Basics
What is medical microbiology?
A subdiscipline of microbiology that studies microorganisms causing human disease, their diagnosis, treatment, and epidemiology.
Medical Microbiology Basics
What is the human microbiota?
All microorganisms present in or on the human body.
Medical Microbiology Basics
What is the human microbiome?
The collective genomes of all microorganisms present in or on the human body.
Medical Microbiology Basics
What types of microorganisms make up the human microbiota?
Bacteria, archaea, fungi, and viruses.
Beneficial Human-Microbial Interactions
How do gut microbes assist in digestion?
They help break down complex carbohydrates into short-chain fatty acids (SCFAs) for energy.
Beneficial Human-Microbial Interactions
Which vitamins are synthesized by gut bacteria?
Vitamin K and B vitamins.
Beneficial Human-Microbial Interactions
How do microbes contribute to immune system modulation?
They train the immune system, regulate inflammation, and protect against pathogens.
Beneficial Human-Microbial Interactions
What is the gut-brain axis?
The communication between gut microbes and the central nervous system via the vagus nerve and microbial metabolites.
Microbial Pathogenesis & Koch’s Postulates
What is microbial pathogenesis?
The process by which microbes cause disease.
Microbial Pathogenesis & Koch’s Postulates
State Koch’s first postulate.
The suspected pathogen must be found in every case of disease and not in healthy individuals.
Microbial Pathogenesis & Koch’s Postulates
List the four steps of pathogenesis.
Exposure
Adhesion
Invasion
Infection
Microbial Pathogenesis & Koch’s Postulates
What is the difference between local and systemic infection?
Local: confined to a small area; Systemic: spreads throughout the body.
Major Pathogen Classes & Examples
What are the pathogenic mechanisms of bacteria?
Toxins (endotoxins & exotoxins), adherence factors, and immune evasion.
Major Pathogen Classes & Examples
Give an example of a bacterial disease and its pathogen.
Tuberculosis, caused by Mycobacterium tuberculosis.
Major Pathogen Classes & Examples
How do viruses cause disease?
By hijacking host cellular machinery and inducing cell lysis.
Major Pathogen Classes & Examples
Give an example of a viral disease.
Influenza, caused by the influenza virus.
Major Pathogen Classes & Examples
How do fungi cause disease?
Through mycotoxin production and opportunistic infections.
Major Pathogen Classes & Examples
Give an example of a fungal disease.
Candidiasis, caused by Candida albicans.
Major Pathogen Classes & Examples
How do parasites cause disease?
By evading the immune system and competing for nutrients.
Major Pathogen Classes & Examples
Give an example of a parasitic disease.
Malaria, caused by Plasmodium species.
Host Defense Mechanisms
What is innate immunity?
A rapid, non-specific immune response that does not require prior exposure to a pathogen.
Host Defense Mechanisms
What are pathogen-associated molecular patterns (PAMPs)?
Unique molecules on pathogens (e.g., LPS, peptidoglycan) recognized by the immune system.
Host Defense Mechanisms
What are the five stages of phagocytosis?
Pathogen engulfed
Phagosome formation
Phagosome binds with lysosome
Pathogen degraded
Debris released
Host Defense Mechanisms
What are the two key characteristics of adaptive immunity?
Specificity and memory.
Host Defense Mechanisms
What is the difference between natural and artificial immunity?
Natural: acquired through infection or maternal antibodies.
Artificial: acquired through vaccination or antibody therapy
Treatment of Infections
What are the four major types of antimicrobial drugs?
Antibiotics, antifungals, antivirals, antiparasitics.
Treatment of Infections
Name an antibiotic-producing microorganism.
Streptomyces species (produces tetracycline, erythromycin).
Antibiotic Resistance
What are two natural mechanisms of antibiotic resistance?
Intrinsic resistance and genetic mutations.
Antibiotic Resistance
What human activities contribute to antibiotic resistance?
Overuse in medicine and agriculture, poor hygiene, global travel.
Antibiotic Resistance
What is horizontal gene transfer (HGT)?
The transfer of genetic material between bacteria, spreading resistance genes.
Antibiotic Resistance
List two ways to prevent antibiotic resistance.
Rational antibiotic use, improved hygiene and infection control.
Bacteriophage Therapy
How do bacteriophages help treat bacterial infections?
They specifically infect and kill antibiotic-resistant bacteria.
Bacteriophage Therapy
What is a key challenge of phage therapy?
Host specificity – phages target specific bacterial strains.
Diagnostic Microbiology
What is the gold standard for pathogen detection?
Direct pathogen identification using culture or molecular methods.
Diagnostic Microbiology
What are two rapid diagnostic techniques?
PCR and lateral flow assays (e.g., COVID-19 tests).
