Chapter 19 Flashcard List: Gram-Positive Bacterial Pathogens

Bacillus anthracis - Organism

Bacillus anthracis

Bacillus anthracis - Disease

Anthrax (cutaneous, inhalation, gastrointestinal)

Bacillus anthracis - Signs/Symptoms

Black skin lesions (eschar), respiratory distress, fever, shock, bloody diarrhea

Bacillus anthracis - Virulence Factors

Polypeptide capsule (anti-phagocytic), anthrax toxin (edema toxin + lethal toxin)

Bacillus anthracis - Additional Notes

Spore-forming, bioterrorism agent

Staphylococcus aureus - Organism

Staphylococcus aureus

Staphylococcus aureus - Diseases

Boils, impetigo, food poisoning, toxic shock syndrome (TSS), pneumonia, endocarditis

Staphylococcus aureus - Signs/Symptoms

Pus-filled skin infections, vomiting/diarrhea, high fever, rash, hypotension

Staphylococcus aureus - Virulence Factors

Protein A (binds antibodies), coagulase (clots plasma), enterotoxins (food poisoning), TSST-1 (toxic shock), hemolysins, leukocidin

Staphylococcus aureus - Additional Notes

MRSA = methicillin-resistant strain

Clostridium perfringens - Organism

Clostridium perfringens

Clostridium perfringens - Diseases

Gas gangrene, food poisoning

Clostridium perfringens - Signs/Symptoms

Tissue necrosis, gas bubbles in tissue, foul odor, diarrhea, cramping

Clostridium perfringens - Virulence Factors

Alpha toxin (lecithinase - destroys cell membranes), multiple other toxins, collagenase, protease

Clostridium perfringens - Additional Notes

Anaerobic, spore-forming

Clostridium botulinum - Organism

Clostridium botulinum

Clostridium botulinum - Disease

Botulism (foodborne, infant, wound)

Clostridium botulinum - Signs/Symptoms

Descending flaccid paralysis, double vision, drooping eyelids, difficulty swallowing, respiratory failure

Clostridium botulinum - Virulence Factors

Botulinum toxin (neurotoxin blocks acetylcholine release)

Clostridium botulinum - Additional Notes

Anaerobic, spore-forming, found in improperly canned foods, most potent toxin known

Clostridium tetani - Organism

Clostridium tetani

Clostridium tetani - Disease

Tetanus (lockjaw)

Clostridium tetani - Signs/Symptoms

Muscle spasms, rigid paralysis, lockjaw, "sardonic smile," arched back (opisthotonos), difficulty breathing

Clostridium tetani - Virulence Factors

Tetanospasmin (neurotoxin blocks inhibitory neurotransmitters)

Clostridium tetani - Additional Notes

Anaerobic, spore-forming, enters through puncture wounds, preventable by vaccine

Corynebacterium diphtheriae - Organism

Corynebacterium diphtheriae

Corynebacterium diphtheriae - Disease

Diphtheria

Corynebacterium diphtheriae - Signs/Symptoms

Gray pseudomembrane in throat, "bull neck" (swollen lymph nodes), sore throat, fever, respiratory obstruction, heart/nerve damage

Corynebacterium diphtheriae - Virulence Factors

Diphtheria toxin (inhibits protein synthesis, causes cell death)

Corynebacterium diphtheriae - Additional Notes

Toxin produced only by lysogenic strains (bacteriophage), preventable by vaccine

Listeria monocytogenes - Organism

Listeria monocytogenes

Listeria monocytogenes - Disease

Listeriosis

Listeria monocytogenes - Signs/Symptoms

Meningitis, septicemia, flu-like symptoms, miscarriage/stillbirth in pregnant women

Listeria monocytogenes - Virulence Factors

Can grow intracellularly, crosses blood-brain barrier, crosses placenta, listeriolysin O

Listeria monocytogenes - Additional Notes

Found in deli meats, soft cheeses, grows at refrigerator temperatures

Mycoplasma pneumoniae - Organism

Mycoplasma pneumoniae

Mycoplasma pneumoniae - Disease

"Walking pneumonia" (atypical pneumonia)

Mycoplasma pneumoniae - Signs/Symptoms

Mild pneumonia, persistent dry cough, low-grade fever, fatigue, headache

Mycoplasma pneumoniae - Virulence Factors

Adhesion proteins (P1 protein), no cell wall

Mycoplasma pneumoniae - Additional Notes

Smallest free-living bacteria, resistant to beta-lactam antibiotics (no cell wall), slow growing

Mycobacterium tuberculosis - Organism

Mycobacterium tuberculosis

Mycobacterium tuberculosis - Disease

Tuberculosis (TB) - pulmonary and extrapulmonary

Mycobacterium tuberculosis - Signs/Symptoms

Chronic cough (>3 weeks), bloody sputum (hemoptysis), night sweats, weight loss, fever, fatigue

Mycobacterium tuberculosis - Virulence Factors

Waxy mycolic acid cell wall (acid-fast), cord factor, survives inside macrophages, resists lysosomal digestion

Mycobacterium tuberculosis - Additional Notes

Spreads by respiratory droplets, forms granulomas (tubercles), requires long antibiotic treatment

Mycobacterium leprae - Organism

Mycobacterium leprae

Mycobacterium leprae - Disease

Leprosy (Hansen's disease)

Mycobacterium leprae - Signs/Symptoms

Skin lesions (patches), nerve damage, loss of sensation/numbness, muscle weakness, disfigurement

Mycobacterium leprae - Virulence Factors

Waxy cell wall (acid-fast), infects peripheral nerves and skin

Mycobacterium leprae - Additional Notes

Very slow growing (doubling time ~14 days), not highly contagious, two forms (tuberculoid and lepromatous)

Streptococcus pneumoniae - Organism

Streptococcus pneumoniae (pneumococcus)

Streptococcus pneumoniae - Diseases

Pneumonia, meningitis, otitis media (ear infection), sinusitis

Streptococcus pneumoniae - Signs/Symptoms

Productive cough with rust-colored sputum, fever, chest pain, rapid breathing, stiff neck (meningitis)

Streptococcus pneumoniae - Virulence Factors

Polysaccharide capsule (major - anti-phagocytic), pneumolysin (destroys cells), IgA protease

Streptococcus pneumoniae - Additional Notes

Leading cause of bacterial pneumonia, vaccine available (pneumococcal vaccine)

Streptococcus pyogenes - Organism

Streptococcus pyogenes (Group A Streptococcus, GAS)

Streptococcus pyogenes - Diseases

Pharyngitis (strep throat), scarlet fever, impetigo, necrotizing fasciitis (flesh-eating disease), rheumatic fever, glomerulonephritis

Streptococcus pyogenes - Signs/Symptoms

Sore throat, fever, red swollen tonsils, sandpaper rash (scarlet fever), rapidly spreading tissue destruction (necrotizing fasciitis)

Streptococcus pyogenes - Virulence Factors

M protein (anti-phagocytic), streptolysins O and S (destroy RBCs/WBCs), streptokinase (dissolves clots), erythrogenic toxin (scarlet fever rash), hyaluronidase (spreading factor)

Streptococcus pyogenes - Additional Notes

Beta-hemolytic, rheumatic fever can damage heart valves

Streptococcus mutans - Organism

Streptococcus mutans

Streptococcus mutans - Disease

Dental caries (cavities)

Streptococcus mutans - Signs/Symptoms

Tooth decay, cavities, tooth pain

Streptococcus mutans - Virulence Factors

Produces lactic acid from sugar (demineralizes enamel), produces dextran from sucrose (sticky biofilm/plaque)

Streptococcus mutans - Additional Notes

Part of normal oral flora, thrives in high-sugar environments