Microbial Diseases – Comprehensive Vocabulary Review (Chs 22‒26)

A set of 141 vocabulary flashcards covering key terms, pathogens, toxins, host defenses, and clinical concepts from Chapters 22 through 26 on microbial diseases of the nervous, cardiovascular/lymphatic, respiratory, urinary, and genital systems.

Central Nervous System (CNS)

The brain and spinal cord; site of information integration and processing.

Peripheral Nervous System (PNS)

Nerves branching from the CNS that carry sensory input to, and motor commands from, the CNS.

Meninges

Three protective membranes (dura mater, arachnoid mater, pia mater) surrounding the brain and spinal cord.

Blood–Brain Barrier (BBB)

Tight endothelial junctions that restrict passage of pathogens, toxins, and many drugs into the CNS.

Cerebrospinal Fluid (CSF)

Fluid in the subarachnoid space that cushions the CNS, supplies nutrients, and removes wastes.

Meningitis

Inflammation of the meninges.

Encephalitis

Inflammation of brain parenchyma.

Meningoencephalitis

Simultaneous inflammation of the meninges and brain tissue.

Bacterial Meningitis

Severe, often rapid meningitis produced by bacteria; characterized by high fever, headache, stiff neck, and possible shock.

Haemophilus influenzae type b (Hib)

Encapsulated Gram-negative coccobacillus that causes childhood meningitis; type b capsule is the major virulence factor.

Hib Vaccine

Conjugate vaccine that induces anti-capsule antibodies and prevents Hib meningitis.

Neisseria meningitidis

Gram-negative diplococcus with polysaccharide capsule; causes meningococcal meningitis and fulminant sepsis.

Petechial Rash

Small hemorrhagic skin spots typical of meningococcemia.

Waterhouse-Friderichsen Syndrome

Adrenal hemorrhage with shock caused by meningococcal endotoxemia.

Lumbar Puncture (Spinal Tap)

Procedure to obtain CSF for diagnosis of CNS infections.

Third-Generation Cephalosporin

β-lactam antibiotic class (e.g., ceftriaxone) with good CNS penetration used empirically for bacterial meningitis.

Listeria monocytogenes

Gram-positive facultative intracellular rod transmitted via food; causes sepsis and meningitis, especially in neonates and immunocompromised.

Listeriolysin O

Listeria pore-forming toxin that enables escape from the phagosome into the cytosol.

Actin “Rocket” Motility

Polymerization of host actin tails by Listeria to propel itself cell-to-cell, avoiding extracellular exposure.

Botulinum Neurotoxin (BoNT)

Clostridial A-B toxin that cleaves SNARE proteins, blocking acetylcholine release and causing flaccid paralysis.

Clostridium botulinum

Gram-positive, endospore-forming anaerobe that produces botulinum toxin; spores common in soil and sediments.

Flaccid Paralysis

Loss of muscle tone due to blocked acetylcholine release, characteristic of botulism.

Infant Botulism

Floppy-baby syndrome from C. botulinum spores germinating in the infant gut.

Tetanospasmin

Clostridium tetani A-B toxin that blocks inhibitory neurotransmitters (GABA, glycine), causing spastic paralysis.

Clostridium tetani

Spore-forming anaerobe from soil; enters deep wounds and produces tetanospasmin.

Spastic Paralysis

Rigid muscle contraction due to unchecked acetylcholine release, seen in tetanus.

Tetanus Toxoid

Inactivated tetanospasmin used in DTaP/Tdap vaccines to induce neutralizing antibodies.

Mycobacterium leprae

Acid-fast intracellular bacterium causing leprosy; prefers cooler peripheral tissues.

Tuberculoid Leprosy

Paucibacillary, localized form with strong cell-mediated immunity and nerve damage.

Lepromatous Leprosy

Multibacillary disseminated form with weak immunity, nodules, and high bacterial load.

Multi-Drug Therapy (MDT)

Long-term regimen of dapsone and rifampin (± clofazimine) used to cure leprosy.

Trypanosoma brucei

Hemoflagellate protozoan causing African sleeping sickness.

Variant Surface Glycoprotein (VSG)

Antigenically variable coat of T. brucei that enables immune evasion.

Winterbottom’s Sign

Posterior cervical lymphadenopathy in early African trypanosomiasis.

Naegleria fowleri

Free-living thermophilic amoeba causing primary amebic meningoencephalitis.

Primary Amebic Meningoencephalitis (PAM)

Rapidly fatal CNS infection by Naegleria fowleri after nasal water exposure.

Rabies Virus

Enveloped, bullet-shaped Lyssavirus that causes fatal encephalitis transmitted by animal bites.

Negri Bodies

Eosinophilic cytoplasmic inclusions in rabies-infected neurons.

Post-Exposure Prophylaxis (PEP)

Immediate wound cleaning, rabies immune globulin, and vaccine series following possible rabies exposure.

Prion

Infectious misfolded protein (PrP Sc) that templates conversion of normal PrP C, causing neurodegeneration.

Transmissible Spongiform Encephalopathy (TSE)

Group of fatal prion diseases producing spongy brain tissue.

Creutzfeldt–Jakob Disease (CJD)

Human prion disease causing rapidly progressive dementia and motor decline.

Sepsis

Systemic inflammatory response (SIRS) triggered by infection.

Septicemia

Acute illness due to pathogens or toxins circulating in blood.

Septic Shock

Sepsis with uncontrolled hypotension leading to multi-organ failure.

Lymphangitis

Inflammation of lymph vessels, often visible as red streaks.

Lipid A

Toxic component of Gram-negative LPS responsible for endotoxic shock.

Enterococcus faecium

Gram-positive nosocomial pathogen, often vancomycin resistant, causing sepsis.

Endocarditis

Inflammation of the heart’s inner lining and valves.

Pericarditis

Inflammation of the fibrous sac surrounding the heart.

Myocarditis

Inflammation of the heart muscle itself.

Tularemia

Zoonotic infection (“rabbit fever”) caused by Francisella tularensis.

Francisella tularensis

Gram-negative intracellular coccobacillus transmitted by rabbits, ticks, or aerosols.

Brucellosis

Undulant fever caused by Brucella spp. acquired from livestock or unpasteurized dairy.

Bacillus anthracis

Gram-positive spore-forming rod causing anthrax.

Protective Antigen (PA)

Anthrax toxin component that delivers LF or EF into host cells.

Lethal Toxin

Anthrax factor (LF + PA) that kills macrophages via MAPK cleavage.

Gas Gangrene

Myonecrosis with gas production caused by Clostridium perfringens.

Clostridium perfringens

Anaerobic, spore-forming rod producing α-toxin and causing gas gangrene.

Hyperbaric Oxygen Therapy

High-pressure oxygen treatment used to inhibit anaerobes in gas gangrene.

Bartonella henselae

Gram-negative rod transmitted by cats; causes cat-scratch disease.

Cat-Scratch Disease

Localized lymphadenitis following a feline scratch or bite.

Yersinia pestis

Gram-negative rod causing plague, transmitted by rat fleas.

Bubonic Plague

Form of plague with swollen, necrotic lymph nodes (buboes).

Pneumonic Plague

Plague form involving lungs; highly contagious and nearly 100 % fatal untreated.

Doxycycline (Plague PEP)

Tetracycline antibiotic used for post-exposure prophylaxis against plague.

Borrelia burgdorferi

Spirochete transmitted by Ixodes ticks; agent of Lyme disease.

Erythema Migrans

Expanding bull’s-eye rash of early Lyme disease.

Rickettsia rickettsii

Obligate intracellular bacterium causing Rocky Mountain spotted fever.

Rocky Mountain Spotted Fever

Tick-borne disease with fever and petechial rash including palms and soles.

Aedes aegypti

Mosquito vector of dengue and other arboviruses.

Antibody-Dependent Enhancement (ADE)

Worsening of dengue infection when non-neutralizing antibodies from a prior serotype facilitate viral uptake.

Trypanosoma cruzi

Flagellated protozoan causing Chagas disease.

Romaña’s Sign

Periorbital swelling in acute Chagas disease.

Toxoplasma gondii

Obligate intracellular protozoan transmitted by cats or undercooked meat; causes toxoplasmosis.

Tachyzoite

Rapidly dividing form of T. gondii during acute infection.

Bradyzoite

Slow-growing, cyst-forming stage of T. gondii persisting in tissues.

Congenital Toxoplasmosis

Fetal infection leading to stillbirth, hydrocephalus, or chorioretinitis.

Plasmodium falciparum

Most severe malaria species causing cerebral malaria and high mortality.

Hypnozoite

Dormant liver stage of Plasmodium vivax and P. ovale that can relapse months later.

Sporozoite

Infective Plasmodium stage injected by Anopheles mosquito.

Merozoite

Plasmodium form that infects red blood cells, causing cyclic fever.

Schistosoma mansoni

Blood fluke species causing intestinal schistosomiasis.

Cercaria

Fork-tailed larval stage of Schistosoma that penetrates human skin.

Miracidium

Free-swimming larva that infects aquatic snails in Schistosoma life cycle.

Upper Respiratory System

Nose, pharynx, middle ear, and eustachian tubes.

Lower Respiratory System

Larynx, trachea, bronchi, and alveoli.

Ciliary Escalator

Mechanism whereby ciliated epithelium moves mucus toward the throat for removal.

Streptococcus pyogenes

Group A β-hemolytic streptococcus causing strep throat and scarlet fever.

Scarlet Fever

Erythrogenic toxin–mediated rash following S. pyogenes pharyngitis.

Corynebacterium diphtheriae

Gram-positive rod that produces diphtheria toxin and pseudomembranes.

Diphtheria Toxin

AB exotoxin that inhibits host protein synthesis by ADP-ribosylating EF-2.

Otitis Media

Middle-ear infection with pus accumulation behind the eardrum.

Rhinovirus

Picornavirus responsible for 30–50 % of common colds.

Canyon Hypothesis

Concept that the rhinovirus receptor site lies in a deep capsid groove protected from antibodies.

Bordetella pertussis

Gram-negative coccobacillus causing whooping cough.

Pertussis Toxin

AB toxin causing systemic lymphocytosis and other effects in pertussis.

Tracheal Cytotoxin

Pertussis peptidoglycan fragment that paralyzes and kills ciliated tracheal cells.

Mycobacterium tuberculosis

Acid-fast rod causing tuberculosis via inhaled aerosols.

Ghon Complex

Calcified caseous lung lesion and lymph nodes indicating healed primary TB.