Microbial Diseases of the Cardiovascular and Lymphoid Systems

Vocabulary flashcards covering major pathogens, diseases, vectors, toxins, and immunological terms from Chapter 23: Microbial Diseases of the Cardiovascular and Lymphoid Systems.

Cardiovascular system

Body system that circulates blood via the heart, arteries, veins, and capillaries to deliver and remove substances from tissues.

Lymphoid system

Network of lymph vessels, nodes, and capillaries that returns interstitial fluid (lymph) to the bloodstream.

Lymphangitis

Inflammation of lymphatic vessels, often visible as red streaks under the skin.

Septicemia

Acute illness caused by pathogens or their toxins in the bloodstream.

Sepsis

Systemic inflammatory response syndrome (SIRS) resulting from infection.

Septic shock

Sepsis accompanied by uncontrollable low blood pressure leading to organ failure.

Endocarditis

Inflammation of the inner lining of the heart (endocardium).

Pericarditis

Inflammation of the sac surrounding the heart; often linked to streptococcal infection.

Myocarditis

Inflammation of the heart muscle itself.

Gram-negative sepsis (endotoxic shock)

Life-threatening condition caused by LPS-producing bacteria such as Klebsiella, E. coli, and Pseudomonas; antibiotics may worsen symptoms by lysing cells.

Gram-positive sepsis

Severe infection with potent exotoxin producers; includes Enterococcus faecium/faecalis and Group B Streptococcus causing neonatal sepsis.

Puerperal sepsis (puerperal fever)

Uterine infection by Streptococcus pyogenes contracted during childbirth that can progress to peritonitis.

Rheumatic fever

Autoimmune complication of S. pyogenes pharyngitis resulting in heart valve inflammation and subcutaneous nodules.

Francisella tularensis

Gram-negative rod that causes tularemia, a zoonosis from rabbits, ticks, or deer flies producing ulcers and enlarged lymph nodes.

Brucellosis (undulant fever)

Zoonotic disease by Brucella spp. transmitted via dairy or animal contact; causes recurrent fever, night sweats, and muscle aches.

Bacillus anthracis

Gram-positive, endospore-forming rod causing anthrax in grazing animals and humans.

Protective antigen

Anthrax virulence protein that binds host cells and allows entry of other toxins.

Edema toxin

Anthrax toxin that causes local swelling and inhibits phagocytosis.

Lethal toxin

Anthrax toxin that kills macrophages, contributing to systemic damage.

Poly-D-glutamic capsule (anthrax)

Protein capsule enabling Bacillus anthracis to evade immune response.

Gas gangrene

Tissue death by Clostridium perfringens growing in necrotic tissue and producing spreading toxins; treated surgically or with hyperbaric oxygen.

Bartonella henselae

Aerobic Gram-negative bacterium causing cat-scratch disease with papule and swollen nodes; usually self-limiting.

Yersinia pestis

Gram-negative rod transmitted by rat fleas; agent of plague.

Bubonic plague

Plague form with bacterial growth in blood and lymph causing buboes; 50–75 % mortality untreated.

Septicemic plague

Plague form where bacteria enter bloodstream causing septic shock.

Pneumonic plague

Plague form infecting lungs; spreads via droplets; nearly 100 % fatal without treatment.

Borrelia burgdorferi

Spirochete causing Lyme disease, the most common U.S. tickborne illness.

Erythema migrans

Bull’s-eye rash characteristic of early Lyme disease.

Rickettsia spp.

Obligate intracellular, Gram-negative bacteria infecting vascular endothelium and spread by arthropods.

Rocky Mountain spotted fever (RMSF)

Tickborne disease by Rickettsia rickettsii with fever and rash on palms/soles; 20 % mortality without doxycycline.

Flavivirus Dengue virus (DENV)

Mosquito-borne virus causing dengue and severe dengue with potential hemorrhage and organ failure.

Antibody-dependent enhancement (ADE)

Phenomenon where heterotypic antibodies from prior DENV infection increase viral entry and disease severity.

Trypanosoma cruzi

Flagellated protozoan causing Chagas disease via reduviid bug feces; chronic infection damages heart, esophagus, colon.

Toxoplasma gondii

Protozoan whose life cycle involves cats; congenital infection can cause fetal brain or eye damage.

Plasmodium vivax

Most common malaria species; forms dormant liver hypnozoites causing relapses.

Plasmodium falciparum

Most severe malaria species; causes high parasitemia and anemia.

Merozoite

Asexual blood stage of Plasmodium that infects red blood cells, leading to cyclical fever.

Schizogony

Asexual reproduction by multiple fission in malaria liver cells and RBCs producing merozoites.

Schistosoma

Genus of blood flukes causing schistosomiasis; eggs induce granulomas in host tissues.

Cercaria

Free-swimming larval stage of Schistosoma that penetrates human skin.

Granuloma (schistosomiasis)

Inflammatory tissue mass around schistosome eggs lodged in organs.

Systemic inflammatory response syndrome (SIRS)

Widespread inflammation often triggered by infection; basis for sepsis definition.

Enterococcus faecalis/faecium

Gram-positive cocci causing hospital-acquired sepsis; often vancomycin-resistant.

Group B Streptococcus (Streptococcus agalactiae)

Gram-positive bacterium causing neonatal sepsis and meningitis.

Streptococcus pyogenes M protein

Surface protein that blocks phagocytosis and triggers autoimmune rheumatic fever via molecular mimicry.

Dermacentor ticks

Wood and dog ticks that transmit Rocky Mountain spotted fever.

Ixodes scapularis

Black-legged tick vector for Lyme disease; has 2-year, 3-host life cycle.

Doxycycline

Tetracycline antibiotic used to treat RMSF, Lyme disease, and anthrax.

Dengvaxia

Live attenuated dengue vaccine approved for 9- to 16-year-olds previously infected.

Hyperbaric oxygen therapy

Treatment delivering high-pressure oxygen to inhibit anaerobes in gas gangrene.

Undulant fever

Intermittent fever pattern characteristic of brucellosis.

Toxic shock syndrome

Severe illness from Gram-positive exotoxins causing hypotension and multi-organ failure.