Microbiology Exam 3 - Vocabulary Flashcards

Vocabulary-style flashcards covering major topics from the lecture notes on innate and adaptive immunity, inflammation, pathogens, vaccines, and key diseases.

Physical barriers

Anatomical defenses (skin, mucous membranes, hair follicles, sweat glands) that block pathogen entry.

Mucous membranes

Line body cavities and passages that secrete mucus to trap and remove pathogens.

Lysozyme

Antimicrobial enzyme in tears, saliva, and mucus that hydrolyzes peptidoglycan in bacterial cell walls.

Sweat (lactic acid and electrolytes)

Sweat contributes to skin acidity and antimicrobial activity through lactic acid and electrolytes.

Skin’s acidic pH and fatty acids

Low pH and fatty acids on the skin inhibit microbial growth.

Hydrochloric acid (stomach)

Acidic environment in the stomach that kills or inhibits many microbes.

Bile and digestive juices (intestines)

Digestive secretions with antimicrobial properties that help limit gut infections.

Resident microbiota

Normal, non-pathogenic microbes that occupy niches and compete with pathogens.

Innate immunity

Non-specific first line of defense that includes physical/chemical barriers and cellular responses.

First line of defense

Physical and chemical barriers that prevent entry of pathogens.

Second line of defense

Internal defenses including phagocytes, inflammation, fever, and antimicrobial proteins.

Adaptive (specific) immunity

Immunity that targets specific antigens with memory, involving B and T cells.

Specific immunity

Adaptive immune response directed at a particular antigen.

Specificity

Ability of the immune system to respond to a single, specific antigen.

Diversity

Presence of many different cells/antibodies capable of reacting with diverse antigens.

Humoral immunity

Adaptive immunity mediated by B cells and antibodies in body fluids.

Cell-mediated immunity

Adaptive immunity mediated by T cells, especially cytotoxic T cells.

Inducibility

Activation of immune responses only when triggered by an antigen.

Clonality

Generation of many cells with identical antigen specificity.

Tolerance

Non-reactivity to self-antigens to prevent autoimmunity.

Memory (immunological)

Rapid, enhanced response upon re-exposure to the same antigen.

Immunogen

Substance that stimulates an immune response (can be an antigen).

Antibody

Protein produced by plasma cells that binds a specific antigen.

B cells

Lymphocytes that mature in the bone marrow and produce antibodies in humoral immunity.

T cells

Lymphocytes that mature in the thymus and regulate or destroy infected cells in cell-mediated immunity.

Plasma cells

Differentiated B cells that secrete large amounts of antibodies.

Red bone marrow

Site of B cell development and maturation.

Thymus

Site of T cell development and maturation.

Neutrophils

Most abundant circulating leukocytes; phagocytes that respond to bacterial infection.

Eosinophils

WBCs that attack parasites and participate in allergic reactions.

Lymphocytes

WBCs (B cells, T cells, NK cells) central to adaptive immunity.

Basophils

WBCs involved in inflammatory responses; contain histamine.

Monocytes

Circulate in blood and differentiate into macrophages or dendritic cells in tissues.

Macrophages

Tissue-resident phagocytes derived from monocytes; digest pathogens and present antigens.

Immunogens

Substances that provoke an immune response.

Vaccination

Artificially inducing active immunity by exposure to a safe antigen preparation.

Natural active immunity

Active immunity acquired through infection; may provide long-lasting protection.

Natural passive immunity

Antibodies transferred from mother to fetus or infant; temporary protection.

Artificial active immunity

Immunity produced by vaccination with a safe antigen.

Artificial passive immunity

Immunity provided by administering antibodies (immunotherapy) for immediate protection.

Treponema pallidum

Spirochete bacterium; causative agent of syphilis.

Chancre

Painless primary lesion at the infection site in primary syphilis.

Gummas

Granulomatous lesions seen in tertiary syphilis.

Congenital syphilis

Syphilis transmitted from mother to fetus with potential fetal harm.

Koplik’s spots

Small white spots on the mucosa seen in measles (early sign).

Measles (rubeola)

Viral disease characterized by fever, rash, and Koplik’s spots.

Chickenpox (varicella) / HHV-3

Primary varicella infection; can reactivate as shingles (HZV).

Shingles (herpes zoster, HHV-3)

Reactivation of latent varicella-zoster virus causing painful dermatomal rash.

Chlamydia trachomatis

Gram-negative bacterium causing chlamydia infections, including ocular and genital disease.

Staphylococcus aureus

Gram-positive cocci in clusters; common pathogen; MRSA variant is antibiotic-resistant.

MRSA

Methicillin-resistant Staphylococcus aureus; difficult-to-treat staph infections.

Streptococcus pyogenes

Gram-positive cocci; causes strep throat, scarlet fever, rheumatic fever.

Scarlet fever

Rash illness following Streptococcus pyogenes infection; characteristic red rash.

Rheumatic fever

Inflammatory complication after streptococcal infection affecting heart and joints.

Glomerulonephritis

Kidney inflammation that can follow streptococcal infection.

Antigenic drift

Gradual small changes in influenza antigens due to mutations; evades memory.

Antigenic shift

Abrupt exchange of gene segments yielding new influenza strains; can cause pandemics.

Mycobacterium tuberculosis

Slow-growing, acid-fast bacterium causing tuberculosis.

Cord factor

Lipid component of mycobacterial cell wall linked to virulence and resistance to drying.

Acid-fast

Stain property of mycobacteria due to mycolic acids in the cell wall.

Mantoux test

Tuberculin skin test to detect TB exposure; measures induration.

PPD (Purified Protein Derivative)

Antigen used in Mantoux test to elicit a delayed hypersensitivity reaction.

IGRA (Interferon-Gamma Release Assay)

Blood test measuring T-cell response to TB antigens.

PCR (Polymerase Chain Reaction)

Molecular method to amplify and detect specific DNA sequences, used for TB testing.

Chest X-ray (in TB)

Imaging used to diagnose pulmonary tuberculosis and assess extent.

Helicobacter pylori

Gram-negative curved rod; causes gastric ulcers; urease raises local pH.

Urease

Enzyme that converts urea to ammonia, increasing local pH and aiding survival.

Pseudomembranous colitis

Colonic inflammation caused by Clostridium difficile; forms pseudomembranes.

Clostridium difficile

Gram-positive, anaerobic, spore-forming rod; antibiotic-associated colitis.

Enterotoxins A and B (C. difficile)

Toxins that damage intestinal walls and cause colitis.

Metronidazole

Antibiotic commonly used to treat C. difficile infections.

Fecal transplant

Therapy restoring healthy gut flora by transplanting fecal material.

Gonococcal/Non-gonococcal infections (contextual)

Noted in lecture as examples of GI/skin pathogens; focus is on toxin- or microbe-related terms.

Hemolytic uremic syndrome (HUS)

Severe condition sometimes caused by STEC, leading to hemolytic anemia and kidney failure.

Shiga-toxin-producing E. coli (STEC)

E. coli producing Shiga toxin; can cause bloody diarrhea and HUS.

Cord factor

Virulence factor in M. tuberculosis—lipid that promotes pathogenicity.

Bacteremia

Presence of bacteria in the bloodstream.

Sepsis

Systemic inflammatory response to infection; can lead to septic shock.

Tetanus (tetanospasmin)

Neuromuscular toxin produced by Clostridium tetani causing rigid paralysis.

Botulism (botulinum toxin)

Intoxication caused by botulinum toxin; causes flaccid paralysis by inhibiting acetylcholine release.

Prions

Infectious proteins causing transmissible spongiform encephalopathies.

TSE (transmissible spongiform encephalopathy)

Neurodegenerative diseases caused by prions (e.g., Creutzfeldt-Jakob).

Antibodies to HIV

Host-produced proteins that recognize HIV antigens; used in diagnosing infection and monitoring disease.

HIV (human immunodeficiency virus)

Virus that infects CD4+ T cells, leading to progressive immune deficiency.

CD4+ T cells (Helper T cells)

T cells that coordinate immune responses; primary targets of HIV.