Bacterial Diseases of Humans Practice Flashcards

Comprehensive vocabulary flashcards covering the characteristics, virulence factors, diseases, and diagnostic features of major bacterial pathogens discussed in the lecture.

Staphylococcus aureus

A Gram-positive cocci bacteria arranged in clusters that is catalase positive, coagulase positive, and a facultative anaerobe.

Coagulase

A virulence factor that forms a clot around bacteria, protecting it from phagocytosis.

Hyaluronidase

A virulence factor known as the "spreading factor" that breaks down connective tissue.

Exfoliative toxin

The toxin produced by Staphylococcus aureus that causes Staphylococcal Scalded Skin Syndrome (SSSS).

Enterotoxin

A toxin that causes food intoxication; in Staphylococcal cases, it results in rapid onset nausea, vomiting, and diarrhea.

DNase

An enzyme that breaks down DNA in pus.

Folliculitis

The mildest skin infection involving the inflammation of a hair follicle.

Furuncle

Also known as a boil, this occurs when a hair follicle infection spreads to the sebaceous gland and forms an abscess filled with pus.

Carbuncle

A large, deep lesion formed by multiple connected furuncles.

Impetigo

A skin infection characterized by blister-like lesions that rupture and form crusts; most common in children and newborns.

Osteomyelitis

A systemic bone infection which can result in abscess formation and bone necrosis.

Bacteremia

A condition where bacteria enter the bloodstream, potentially leading to endocarditis and septicemia.

Toxic Shock Syndrome (TSS)

A toxigenic disease characterized by fever, rash, hypotension, shock, and organ failure.

Streptococcus pyogenes

A Gram-positive cocci arranged in chains that is $\beta-hemolytic$ and a strict human parasite.

M protein

The major anti-phagocytic virulence factor found in Streptococcus pyogenes.

Erythrogenic toxin

The specific toxin responsible for causing the bright red rash associated with scarlet fever.

Erysipelas

A localized streptococcal infection where bacteria enter through a break in the skin, causing bright red, swollen skin.

Necrotizing Fasciitis

Commonly called "flesh-eating disease," where exotoxins rapidly destroy tissue.

Rheumatic Fever

An immune-mediated ($\text{Type II}$ hypersensitivity) complication of untreated strep throat that can damage heart valves.

Acute Glomerulonephritis

An immune-mediated ($\text{Type III}$ hypersensitivity) kidney inflammation resulting from a previous streptococcal infection.

Viridans Streptococci

A group of $\alpha-hemolytic$ bacteria that are normal flora of the teeth, gums, and oral cavity.

Subacute Endocarditis

A condition where bacteria attach to damaged heart valves and form vegetations (biofilms) after entering the bloodstream.

Streptococcus pneumoniae

A Gram-positive diplococci described as lancet-shaped and $\alpha-hemolytic$, which utilizes a capsule as its major virulence factor.

Neisseria gonorrhoeae

A Gram-negative diplococci that causes a sexually transmitted infection (STI) and requires fimbriae for attachment.

Ophthalmia neonatorum

A gonococcal eye infection in newborns that can lead to blindness if not treated with prophylaxis.

Neisseria meningitidis

The Gram-negative diplococci responsible for meningococcal meningitis, often spread in crowded environments like college dormitories.

Petechiae

Small red or purple spots on the skin caused by minor hemorrhage, seen in meningococcemia.

Clostridium tetani

A Gram-positive, spore-forming, obligate anaerobic rod that causes lockjaw.

Tetanospasmin

A neurotoxin that blocks inhibitory neurotransmitters, causing continuous muscle contraction or spastic paralysis.

Opisthotonos

A late-stage symptom of tetanus involving the severe arching of the back due to muscle spasms.

Clostridium botulinum

A Gram-positive, spore-forming, obligate anaerobic rod that causes botulism.

Botulin toxin

A potent toxin that blocks the release of acetylcholine, leading to flaccid paralysis.

Infant Botulism

Also known as "Floppy Baby Syndrome," caused by the ingestion of spores, often from raw honey.

Mycobacterium tuberculosis

An acid-fast, slow-growing, strict aerobic bacillus whose cell wall contains mycolic acid.

Tubercles

Granulomas formed during primary tuberculosis when the immune response traps bacteria inside alveolar macrophages.

Pseudomonas aeruginosa

An opportunistic Gram-negative rod that produces a blue-green pigment called pyocyanin and a grape-like odor.

Francisella tularensis

The causative agent of Tularemia (Rabbit Fever), characterized by a very low infectious dose of $10-50$ bacteria.

Bordetella pertussis

An encapsulated Gram-negative coccobacillus that causes Whooping Cough by destroying ciliated respiratory cells.

Enterohemorrhagic E. coli (EHEC)

The $O157:H7$ strain that produces Shiga toxin and can lead to bloody diarrhea and kidney damage ($\text{HUS}$).

Salmonella Typhi

The human-reservoir pathogen that causes Typhoid Fever and can be harbored chronically in the gallbladder.

Yersinia pestis

A Gram-negative rod showing bipolar staining ("safety pin") that causes the plague.

Buboes

The painful, swollen lymph nodes characteristic of bubonic plague.

Haemophilus influenzae

A fastidious Gram-negative rod that requires factors from red blood cells and can cause meningitis or epiglottitis.

Treponema pallidum

A Gram-negative spirochete and human reservoir-only pathogen that causes syphilis.

Chancre

A painless ulcer that develops at the site of infection during primary syphilis.

Gummas

Soft tissue lesions that develop during the tertiary stage of syphilis.

Borrelia burgdorferi

A Gram-negative spirochete transmitted by Ixodes ticks that causes Lyme disease.

Erythema migrans

The "bull's-eye" rash that serves as an early sign of Lyme disease.

Campylobacter jejuni

A Gram-negative, curved, S-shaped rod that is a common cause of bacterial gastroenteritis linked to undercooked poultry.

Rickettsia rickettsii

A Gram-negative, obligate intracellular coccobacillus that causes Rocky Mountain Spotted Fever via tick bites.

Chlamydia trachomatis

The second most common STI, an obligate intracellular bacterium that exists in infectious elementary bodies and reproductive reticulate bodies.