Lecture 16 - Chapter 19 Pathogenic Gram Positive Bacteria

Front 1

Staphylococcus

Back 1

•Facultative anaerobic - live w/O2 but doesn't need it

•Bile Salts

•Catalase - breaks down H2O2

•Coagulase - cause blood to clog

•S.aureus (+) Coagulase

•S.epidermidis (-) Coagulase

Front 2

Staphylococcus aureus (+) Coagulase

Back 2

•exotoxins (e.g. exfoliatin)

•produces protein A

•prevents opsonization & phagocytization

•strong IgG

•weak IgA & IgM

Hint 2

allows to invade immune system

Front 3

Staphylococcus: Cutaneous

Back 3

•Causes skin infection

•Folliculitis (carbuncles, furuncles)

•Impetigo

Front 4

Staphylococcus: Systemic

Back 4

•Acute infective endocarditis (damage in heart valves)

•Osteomyelitis (bone marrow possible infected)

•Pneumonia (bronchopneumonia & lobar)

•Septicemia (gets into blood stream)

Front 5

Staphylococcus: Toxins

Back 5

•Food Poisoning
•Gastroenteritis

•Staphylococcal Scalded skin syndrome (skin infection where toxin exfoliate cause skin to separate like 2nd degree burns in infants)

•Toxic Shock syndrome - caused by tampons

Front 6

Staphylococcus: Treatment

Back 6

•amoxicillin/clavulanate, erythromycin (beta lactamase)

•Vancomycin, nafcillin, oxacillin (stronger antibiotics admitted to hospital)

Front 7

Streptococcus

Back 7

•Facultative anaerobe - live w/O2 but doesn't need it

•(-) Catalase

•(-) Coagulase

•α hemolysis (partial)

•β hemolysis (completely)

•Y hemolysis (no breakdown)

Front 8

Streptococcus: α hemolytic

Back 8

•S.Viridans - Dental Caries

•S. pneumoniae

•Cellulitis - skin infection

•Lobar Pneumonia

•Meningitis

•Otitis Media

•URTI (bronchitis, sinusitis) - respiratory infection

Front 9

Streptococcus: β hemolytic

Back 9

Divided to groups per carbohydrates present on cell wall

•Group A - G (based on A, B, D)

Front 10

Group A Streptococcus(GAS) - S.pyogenes (pus producing)

Back 10

•M Proteins- Binds to C3b, prevents opsonization & phagocytosis (similar to protein A)
•Streptolysin- exotoxin; causes RBC lysis (beta hemolytic)

•Streptokinase- activates plasminogen cascade to promote fibrinolysis (stop clogging)

•Streptococcal pyrogenic exotoxins - exotoxins; superantigen (binds multi-antibodies cause body immune response)

Front 11

Streptococcus: GAS diseases

Back 11

•Impetigo (vesicular, blistered eruption common in children)
•Necrotizing Fasciitis (flesh eating disease)
•Pneumonia
•Scarlet Fever (pyrogenic emoticon, spares the face)

•Streptococcal Pharyngitis (strep throat)

Front 12

Streptococcus: Complications of GAS infection?

Back 12

•Glomerulonephritis (kidneys)

•Rheumatic Fever (joint problems, heart damaged, pneumatic heart failure 20 yrs later in western countries)

Front 13

Group B Streptococcus (GBS) B for Baby

Back 13

•S.Agalactiae - found in GI & GU tract

•Causes pneumonia & meningitis (inoculating into body lung cavity, prophylactic & penicillin drugs)

•Increase PROM in pregnancy

Front 14

Group D Streptococcus (GDS)

Back 14

•Facultative anaerobic (in GI don't like O2 but will tolerate, harsh environment)

•Re-classified as Enterococcus

•Tolerant Of a wide range of environments

Front 15

Enterococcus: E. faecalis

Back 15

E.faecalis

Front 16

Enterococcus: E. faecium

Back 16

•Relatively harmless unless gets into other parts of the body

•Intrinsically resistant antibiotics (strong antibiotics needed)

•UTI (disease caused)

•Meningitis (disease cause pathogen)

•Diverticulitis (colon inflammation)

•Endocarditis (septic)

Front 17

Bacillus

Back 17

•Obligate Aerobe (requires O2) or facultative anaerobe (live w/O2 but ferment w/o O2)

•(+) Catalase in the presence of oxygen

•Endospore & Non-endospore

•B.anthracis (pathogenic both endospores)

•B.cereus (food poisoning on rice bacillus dies but not endospores)

Front 18

Bacillus anthracis

(fatal if untreated)

Back 18

•Cutaneous: Contact w/endospores, inflammation, formation of eschar (black, painless lesion; formed necrotic tissues), can cause toxemia

•Gastrointestinal: Ingestion of infected meat, lesions in the GI, massive GI hemorrhage
•Pulmonary: Inhalation of endospores, bacteria produce toxins in lungs causing toxemia (deadly)

Front 19

Bacillus anthracis: Vaccines available?

Back 19

•Antibiotic - erythromycin, fluoroquinolones, vancomycin

•Monoclonal antibodies

Front 20

Clostridium

Back 20

•Obligate anaerobes (requires O2 to survive)

•Endospores

•Significant pathogenic clostridium

•C.botulinum; C.difficile; C.perfringens; C.tetani

Front 21

Clostridium perfringens

Back 21

•Endospores survive high temperatures: germination of endospores causes gastroenteritis •Rare, C. perfringens cause Clostridial necrotizing enteritis (necrotizing inflammation of small bowel caused by B-toxin)

•Toxin necrotizing damage to muscles leading to gas gangrene

•Produces enterotoxins: food poisoning

Hint 21

Severe gangrene treated: hyperbaric (high pressure)

Less severe - no antibiotics

Front 22

Clostridium difficile

Back 22

•Anaerobic, endospores producing
•Causes Pseudomembranous colitis (inflammation of large intestine)

•Toxin A (enterotoxin) (food poisoning)

•Toxin B (cytotoxin) (kills cell w/in 24 hrs )

Hint 22

What would you prescribe? Metronidazole & vancomycin

Front 23

Clostridium difficile pseudomembrane form from?

Back 23

exudate & composed of dead WBC cells, fibrin

Front 24

Clostridium difficile intrinsic antibiotic resistance?

Back 24

pseudomembrane & formation of endospores makes treatment difficult

Front 25

Clostridium botulinum

Back 25

•Anaerobic, endospores producing
•Botulinum toxin (neurotoxin)

•Ingestion of spores & subsequent germination of the spores lead botulinum toxins being released within the GI tract

(Botulism & infantile botulism)

•Injection of spores into wounds cause the toxins to released into bloodstream

(Wound Botulism)

Hint 25

•Affect cranial nerves; eyesight, eyelids drop, speak, chewing, effect arms/legs, stop respiratory breathing, conscience live

•Botulism - flaccid

•Infant botulism - flopping baby syndrome

•Wound Botulism - intravenous drugs

Front 26

Clostridium botulinum treatment?

Back 26

•Antibodies for toxin (Antitoxin)

•Supportive care

Hint 26

Fatal if untreated

Front 27

Clostridium tetani

Back 27

•Anaerobic, endospores producing

•Two exotoxin - Tetanolysin (don't know)

•Tetanospasmin (neurotoxin - spasms, paralysis, painful contracting unable to move)

Front 28

Clostridium tetani introduced through?

Back 28

Wounds

Front 29

Clostridium tetani treatment?

Back 29

•Antitoxin

•Benzodiazepam - spasms, sleep aid

•Booster shots

•Metronidazole