Bacterial Diseases Lecture Review

Practice flashcards covering the characteristics, epidemiology, and pathogenesis of major bacterial pathogens including Cocci, Gram-positive Bacilli, and Gram-negative Bacilli as discussed in Unit 5.

Staphylococcus aureus

A species that grows in large, round, yellow (gold) colonies at an optimum temperature of $37^{o}C$, characterized as a facultative anaerobe that withstands high salt and extremes in pH.

Coagulase

An enzyme and virulence factor produced by Staphylococcus aureus used as a key identifying characteristic in laboratory samples.

MRSA

An acronym for methicillin-resistant Staphylococcus aureus, which carries multiple resistance to almost all penicillins and accounts for $80\times$ of Staph infections.

Furuncle

A boil caused by inflammation of a hair follicle or sebaceous gland that progresses into an abscess or pustule.

Carbuncle

A large and deep skin lesion created by the interconnection of a cluster of furuncles.

Osteomyelitis

A systemic staphylococcal infection established in the metaphysis of bone, leading to abscess formation, tenderness, and necrosis.

Staphylococcal scalded skin syndrome (SSSS)

A toxigenic disease where a toxin induces a bright red flush and blisters, followed by desquamation of the epidermis.

$\beta$-hemolysis

A classification of streptococci, including Streptococcus pyogenes and S. agalactiae, based on their ability to completely lyse red blood cells.

Streptococcal pharyngitis

Commonly known as strep throat, an infection of the throat that can lead to tonsillitis and purulent exudate.

Necrotizing Fasciitis

A rare condition where infecting Streptococci release exotoxins that poison epidermal and dermal tissues, causing the flesh to die and slough off.

Rheumatic fever

A long-term complication of S. pyogenes that can cause arthritis, chorea, and carditis with extensive valve damage, occurring as an immune reaction to primary infection.

Viridans Group

A large complex group of $\beta$-hemolytic streptococci, including S. mutans, which are widespread residents of the oral cavity and can cause subacute endocarditis.

Streptococcus pneumoniae

Also called the pneumococcus, this lancet-shaped bacterium causes $60-70\times$ of all bacterial pneumonias and requires $5-10\times$ $CO_2$ for improved growth.

Specific soluble substance (SSS)

A sugar antigen expressed as part of the capsule in S. pneumoniae, with $90$ different capsular types identified.

Neisseria gonorrhoeae

A Gram-negative, bean-shaped diplococcus that causes gonorrhea, utilizing fimbriae for attachment and IgA protease to inhibit secretory antibodies.

Meningococcemia

A condition where Neisseria meningitidis stays in circulation, shedding LPS that stimulates cytokine-mediated blood vessel destruction and petechiae.

Tetanospasmin

A paralyzing neurotoxin produced by Clostridium tetani that blocks the release of neurotransmitters for muscular contraction inhibition, leading to uncontrollable contractions.

Risus sardonicus

The characteristic 'sardonic grin' resulting from jaw muscle spasms during the early stages of tetanus.

Botulin

A potent exotoxin produced by Clostridium botulinum that blocks the release of acetylcholine at neuromuscular junctions, causing flaccid paralysis.

Floppy baby syndrome

The common name for infant botulism, characterized by flaccid paralysis caused by ingested spores germinating in the immature infant immune system.

Cord factor

A virulence factor in Mycobacterium tuberculosis that causes the bacilli to grow in long strands and prevents destruction by lysosomes or macrophages.

Mantoux test

A diagnostic procedure for tuberculosis involving the local intradermal injection of purified protein derivative (PPD) to observe for a red wheal called an induration.

Pyocyanin

A water-soluble 'blue pus' pigment produced by Pseudomonas aeruginosa, which also gives off a grapelike odor.

Tularemia

Also known as rabbit fever, this zoonotic disease is caused by Francisella tularensis and is considered a potential bioterrorism agent due to its low infectious dose of $10-50$ bacteria.

Bordetella pertussis

A minute, encapsulated coccobacillus that causes whooping cough by binding to and destroying ciliated respiratory epithelial cells.

Escherichia coli O157:H7

A hemorrhagic strain of E. coli that contains genes for the shiga toxin and is identified in the lab when colonies appear black on Rainbow Agar.

Salmonella typhi

The most serious pathogen of its genus and the causative agent of typhoid fever, which can lead to septicemia and ulceration of the intestinal wall.

Yersinia pestis

The Gram-negative rod responsible for the plague, characterized by unusual bipolar staining and transmission through flea vectors.

Bubo

A swelling and necrosis of a lymph node, typically in the groin or axilla, that occurs during bubonic plague.

Treponema pallidum

The fastidious, coiled spirochete that causes syphilis and is strictly a human parasite.

Hard chancre

The primary symptom of the first stage of syphilis, appearing at the site of inoculation and healing spontaneously after $3-6$ weeks.

Gummas

Painful, necrotic lesions that develop in various tissues and organs during the tertiary stage of syphilis.

Borrelia burgdorferi

The large, irregularly spaced spirochete that causes Lyme disease and is transmitted by Ixodes ticks.

Rickettsia rickettsii

The causative agent of Rocky Mountain Spotted Fever, which acts as an obligate intracellular parasite that causes necrosis of the vascular lining.

Elementary body

The small, metabolically inactive, extracellular, and infectious form of Chlamydia that is released by the infected host cell.