Comprehensive Microbiology Final Exam Study Guide (Chapters 1–21)

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Chapter 13 – Immune System Disorders

Immune Deficiencies

Immune deficiencies are conditions in which the immune system's ability to fight infectious disease is compromised or entirely absent.

Primary (Inborn) Immunodeficiencies: Genetic or developmental defects present from birth. About 50% are due to B cell malfunction, 30% to T cell malfunction. Example: DiGeorge syndrome (chromosome 22 deletion, impaired thymus).
Secondary (Acquired) Immunodeficiencies: Develop later in life due to aging, medical interventions, systemic disorders (e.g., kidney disease), or drugs (anticonvulsants, corticosteroids, immunosuppressants). HIV targets T cells, leading to AIDS when T cell count drops. Epstein-Barr virus can cause blood cancers by affecting lymphocytes.
SPUR Criteria: Severe, Persistent, Uncommon, Recurring infections suggest immunodeficiency.

Autoimmune Diseases

Autoimmune diseases occur when the immune system attacks the body's own tissues due to loss of self-tolerance in B or T cells.

Systemic Autoimmune Diseases: Affect multiple tissues (e.g., systemic lupus erythematosus).
Localized Autoimmune Diseases: Target specific tissues (e.g., rheumatoid arthritis).

Hypersensitivities

Hypersensitivities are inappropriate or exaggerated immune responses. There are four types:

Type	Description	Antibody/Cell Involved	Triggers	Mechanism	Examples
I	Allergies (immediate)	IgE	Soluble antigens, drugs	IgE binds antigen, triggers allergic response	Atopic asthma, dermatitis
II	Cytotoxic	IgG, IgM	Cell surface/extracellular antigens, drugs	IgG/IgM bind targets, cause cell damage	Goodpasture syndrome, hemolytic anemia
III	Immune complex	IgG, IgM	Soluble antigens	Immune complexes deposit in tissues, activate complement	Lupus, rheumatoid arthritis, serum sickness
IV	Delayed (cell-mediated)	T cells	Soluble/cell-bound antigens, drugs	T cells drive delayed inflammation	Poison ivy, TB test, MS, Hashimoto's

Chapter 14 – Biomedical Applications: Vaccines, Diagnostics, and Molecular Methods

Vaccine History and Types

Vaccines have reduced or eradicated serious infections and promote herd immunity. Key contributors include Edward Jenner and Louis Pasteur.

Live Attenuated Vaccines: Weakened pathogens (e.g., MMR vaccine).
Vector Vaccines: Genetically modified viruses deliver pathogen genes.
Inactivated Vaccines: Whole (entire inactivated pathogen) or subunit (parts of pathogen).
mRNA Vaccines: Host cells produce pathogen protein from mRNA (e.g., COVID-19 vaccines).

Immunologic Tests

Used to identify pathogens, determine exposure or immunity, and detect specific antigens/antibodies in serum.

Protocols: Obtain serum from blood, test for antigens/antibodies.
Types: Agglutination, neutralization/PRNT, ELISA, fluorescent antibodies, IGRAs.

Genetic Manipulations

Genetic Engineering: Combine DNA from two sources, insert into vectors, transform cells, produce drugs/products.
PCR/RT-PCR: Amplify DNA/RNA, detect genes, diagnostics.
CRISPR-Cas9: Gene editing using guide RNA and Cas9 enzyme.
Gene Therapy: Deliver normal genes via engineered viruses to treat genetic disorders.
Genome Mapping: Record gene locations, support medical studies.
Gene Microarrays: Measure gene expression, identify pathogens, diagnose diseases.

Chapter 15 – Antimicrobial Drugs

Classifications and Key Concepts

Broad Spectrum: Effective against Gram-positive and Gram-negative bacteria.
Narrow Spectrum: Target limited range (e.g., quinolones).
-static vs -cidal: Bacteriostatic (inhibit growth), bactericidal (kill bacteria).
Therapeutic Index:
Route of Administration: Oral, intravenous, topical, etc.
Selective Toxicity: Kills microbes without harming host cells.

Major Antimicrobial Classes

Class	Structure/Mechanism	Spectrum	Examples	Side Effects
Penicillins	Beta-lactam ring, block cell wall synthesis	Broad	Amoxicillin	Rash, GI upset
Glycopeptides	Block cell wall, no beta-lactam ring	Narrow	Vancomycin	Nausea, red man syndrome
Quinolones	Inhibit DNA replication	Broad	Ciprofloxacin	Nausea, headache, tendinitis
Antifolates	Block folic acid synthesis	Broad	Sulfa drugs	Allergic reactions
Macrolides	Bind 50S ribosome, block protein synthesis	Broad	Erythromycin	GI upset
Polypeptides	Disrupt Gram-negative membranes	Narrow	Polymyxin B	Nephrotoxicity

Other Antimicrobial Agents

Antivirals: Target viral replication steps (e.g., remdesivir for SARS-CoV-2).
Antifungals: Disrupt plasma membrane, cell wall, or nucleic acids (e.g., azoles, polyenes).
Antiprotozoals: Disrupt metabolism or nucleic acids (e.g., chloroquine, metronidazole).
Antihelminths: Inhibit glucose uptake or paralyze worms (e.g., albendazole, praziquantel).

Assessing Antimicrobial Sensitivity

Kirby-Bauer Test: Measures zone of inhibition on agar plate.
E-test: Uses gradient strip to determine minimum inhibitory concentration (MIC).
Broth Dilution Test: Determines MIC and minimum bactericidal concentration (MBC).

Drug Resistance

Acquisition: Mutation, horizontal gene transfer.
Mechanisms: Enzyme production, efflux pumps, target modification.
Prevention: Appropriate use, patient compliance, infection control.

Chapters 1–12: Foundational Microbiology Concepts

Introduction to Microbiology

Definition: Study of microscopic organisms (bacteria, viruses, fungi, protozoa, algae).
Endosymbiotic Theory: Eukaryotic organelles (mitochondria, chloroplasts) originated from prokaryotes.
Key Contributors: Hooke, van Leeuwenhoek, Pasteur, Koch, Semmelweis, Lister, Nightingale.
Taxonomy: 8 levels; binomial nomenclature (genus species).
Three Domains: Bacteria, Archaea, Eukarya.
Symbiosis: Mutualism, commensalism, parasitism.
Normal Microbiota: Microbes normally present in/on the body; protect against pathogens.
Biofilms: Microbial communities attached to surfaces; increased resistance.
Growth Media: Nutrient agar, broth; used for culturing microbes.
Streak Plate: Isolates pure colonies.
Staining: Gram, acid-fast, endospore stains for identification.
Microscopy: Light, electron, fluorescence microscopy for visualization.

Biochemistry Basics

Atoms, Ions, Isotopes: Basic units of matter; ions have charge; isotopes differ in neutrons.
pH Scale: Measures acidity/alkalinity;
Chemical Bonds: Ionic, covalent, hydrogen, Van der Waals.
Polarity: Affects solubility and membrane transport.
Macromolecules: Carbohydrates, lipids, nucleic acids, proteins.
Enzymes: Biological catalysts; lower activation energy.

Prokaryotic and Eukaryotic Cells

Prokaryotes: Bacteria, Archaea; no nucleus; binary fission.
Eukaryotes: Nucleus, organelles; mitosis/meiosis.
Cell Structures: Capsule, cell wall, plasma membrane, flagella, fimbriae, pili.
Transport: Diffusion, osmosis, active transport, endocytosis.
Kingdoms: Animalia, Plantae, Fungi, Protists.

Genetics

Genome: Complete genetic material.
Central Dogma: DNA → RNA → Protein.
DNA Replication: Semi-conservative, enzymes (helicase, DNA polymerase).
Gene Expression: Transcription (RNA polymerase), translation (ribosomes).
Mutations: Changes in DNA; caused by mutagens.
Horizontal Gene Transfer: Conjugation, transformation, transduction, transposons.

Viruses and Prions

Viruses: Acellular, require host; DNA or RNA genomes.
Replication: Lytic and lysogenic cycles (phages); animal virus replication.
Oncoviruses: Cause cancer (e.g., HPV, EBV).
Prions: Infectious proteins; cause neurodegenerative diseases.

Microbial Growth and Metabolism

Biofilms: Structured communities; increased resistance.
Growth Phases: Lag, log, stationary, death.
Metabolism: Catabolism (breakdown), anabolism (synthesis).
ATP Generation: Substrate-level, oxidative, photophosphorylation.
Fermentation: Anaerobic energy production.

Principles of Infectious Disease and Epidemiology

Pathogens: Bacteria, viruses, fungi, protozoa, helminths.
Koch's Postulates: Criteria for linking microbes to disease.
Transmission: Direct, indirect, vector-borne.
Epidemiology: Study of disease patterns; measures of frequency and association.

Host-Microbe Interactions and Immunity

Virulence: Degree of pathogenicity; ID50, LD50.
Infection Steps: Entry, adherence, invasion, evasion, damage.
Innate Immunity: First-line (barriers), second-line (cells, molecules, inflammation, fever).
Adaptive Immunity: Humoral (B cells, antibodies), cellular (T cells).
Immune Memory: Basis for vaccination.

Essay Preparation: Organ System Disease Profiles

For each organ system (respiratory, skin, nervous, digestive, urinary/reproductive, cardiovascular/lymphatic):
- Outline structure and function, susceptibility/protection against disease.
- Describe a relevant infectious disease: pathogen, pathogenesis, virulence, susceptible groups, transmission, progression, signs/symptoms, diagnosis, prevention/treatment.

Additional info: This guide covers all major topics from the course, including foundational concepts, current biomedical applications, and antimicrobial strategies. For essay questions, review your organ system summaries and disease profiles in detail.