Infectious Diseases (Part 3: Microorganisms)

Toxin mediated, causing toxic shock syndrome and scalded skin syndromes. Also causes wound and deep tissue infections. Increasing antibiotic resistance (MRSA, VISA, VRSA) is a major concern.

Primarily Staphylococcus epidermidis. Adheres to medical devices via slime. Resists phagocytosis using glycocalyx. Can cause skin infections, cellulitis, GI infections, and form biofilms.

Protein F and M protein aid in tissue invasion. Streptococcal pyrogenic exotoxin mediates rash and systemic effects. Antibodies can cross-react with heart tissue and cause kidney damage.

Affects infants and mothers. Uses a capsule for virulence, causing meningitis, pneumonia, postpartum infections, and skin/soft tissue infections in newborns.

Gram-positive, lance-shaped with a capsule. Capsule inhibits phagocytosis. Can cause sinusitis, otitis media, meningitis and pneumonia; resistance to drugs is common.

Causes subacute bacterial endocarditis (SBE), particularly in patients with damaged heart valves. Normally part of the mucosal flora.

Causes dental cavities (caries). Forms complex polysaccharides, enhancing attachment to host surfaces to create plaque.

Causes nosocomial infections, UTIs, bacteremia, and infections of the abdomen and pelvis. Adheres to surfaces, proliferates, and exhibits antibiotic resistance.

Vancomycin-resistant enterococci. Can spread person-to-person and persist in environments. Often exhibit high-level aminoglycoside resistance.

Gram-positive coccobacilli. Food-borne illness from dairy and processed foods. Makes listeriolysin, allowing survival in phagocytes. Survives low temperatures.

Spread via droplet nuclei. Has mycolic acid, stains acid-fast. PPD skin test detects delayed hypersensitivity (redness, swelling).

Gram-positive, spore-forming rod that produces exotoxins. Causes gastroenteritis with vomiting, diarrhea, and nausea. Can cause severe ocular infection after trauma.

Gram-positive rod with boxcar morphology. No spores. Causes gas gangrene via toxin-mediated tissue breakdown. Double zone of beta-hemolysis.

Produces cytotoxin B and enterotoxin A. Causes antibiotic-associated pseudomembranous colitis. Disrupts normal flora. Horse stable odor; causes diarrhea.

Produces a neurotoxin that inhibits muscle contraction. Gram-positive rod with terminal spores (tennis racket shape). Associated with puncture wounds; causes tetanus.

Causes colorectal carcinoma with high mortality. Gram-positive, spore-forming rod. Isolated in blood or wound cultures. Found in the GI tract.

Gram-negative rod found in fecal matter. Virulence factors: endotoxin, capsule production, pili/fimbriae. Causes UTIs, bacteremia, nosocomial infections, diarrhea, dysentery.

Pesutus causes the plague. Enterolitica attaches to and invades intestinal mucosa, spreading to lymphatic tissue.

Gram-negative rod that is non-lactose fermenting. Zoonotic foodborne illness (poultry). Makes endotoxin. Causes gastroenteritis, bacteremia, enteric fever (typhoid fever).

Gram-negative enteric rod (non-lactose fermenter). Agent of bacillary dysentery. Produces Shiga toxin, causing adherence, invasion, intracellular spread, and inflammation.

Causes swimmer's ear, cystic fibrosis complications, and wound infections in burn patients. Also causes neutropenic fever.

Encapsulated; evades the complement system. Causes meningococcemia (systemic bloodstream infection) and meningococcal meningitis (fast, fulminant meningitis).

Gram-negative diplococci, oxidase-positive. Ferments only glucose. Sexually transmitted disease (STD).

Gram-negative coccobacilli, tiny, faintly staining. Requires hemin and NAD for growth. Causes pink eye and meningitis, particularly in children.

Gram-negative rod that lives in freshwater and heating/cooling systems. Transmitted by aerosolized water. Requires cysteine-containing media for growth.

Gram-negative bipolar coccobacilli that needs nicotinic acid to grow. Causes whooping cough. Adheres via fimbriae. Grows in the trachea.

Gram-negative, comma-shaped rod. Food-borne and found in shellfish. Causes cholera, resulting in rice water stool (water and mucous membranes) and severe dehydration.

Gram-negative spiral that causes gastritis and peptic ulcer disease. Survives stomach pH by rapidly hydrolyzing urea. S-shaped or seagull wing appearance.

Gram-negative, "seagull" shaped, oxidase-positive, catalase-positive, and microaerophilic. Causes gastroenteritis. Food-borne, water-borne, or from puppies.

Spirochete transmitted by deer tick bites, causing Lyme disease. Presents with arthritis and bull's-eye rash.