Clostridium Spp.

Front 1

Taxonomic classifcation Clostridium spp? (6)

Back 1

Kingdom - Bacteria
Phylum - Firmicutes
Class - Clostridia
Order - Clostridiales
Family - Clostridiaceae
Genus - Clostridium

Front 2

Clostridium spp. characteristics? (6)

Back 2

1. GPR - obligate anaerobic spore forming
2. Spore deforms cell
3. Spore variations to spp.
4. Flagella (+) (not C. perfringens)
5. Loci: soil + normaflora (i.e. gut, feces)
6. Lecithinase (+)
6. LT survival
7. Gas produces + high biochemical activity

Front 3

Clostridium spp. are distinguished based on? (3)

Back 3

Pathomechanism:
i. gas gangrene/histolytic - C. perfringens
ii. Neurotoxic - C. tetani + C. botulinum
iii. Enteric - C. difficile

Front 4

Clostridium perfringens characteristics ? (6)

Back 4

1. GPR - obligate anaerobe spore forming
2. Flagella (-)
3. Capsule (+)
4. Central spore, pear-shaped rod
5. Double hemolytic zone (blood agar)
6. High gas producer

Front 5

C. perfringens VFs: EXOENZYMES? (3)

Back 5

1. Collagenase
2. Hyaluronidase
3. DNAse

Front 6

C. perfringens VFs: SURFACE MOLECULES?

Back 6

Capsule (12 different capsular AGs)

Front 7

C. perfringens VFs: EXOTOXINS (membrane damaging)? (5)

Back 7

Nercotizing and hemolysing toxins
- alpha toxin (lecithinase, PLC --> *lysis)
- beta toxin (necrotizing)
- epsilon toxin (increases vascular permeability of GI)
- Iota toxin (*ADP-ribosylation of actin --> *necrosis)
Enterotoxin (*food poisoning, GI diseases)

Front 8

What is a spp. specific variant of the Lecithinase rxn?

Back 8

Nagler-reaction (target = C. perfringens)

Front 9

Nagler-reaction?

Back 9

- Egg yolk medium
- Antitoxin blocks lecithinase prod. via C. prefringens
- turbidity opalescence due to lecithinase prod.

Front 10

Toxinogenic strains: C. prefringens?

Back 10

Types: A-E

Front 11

What are the most freq. causative agents of GAS GANGRENE? (2)

Back 11

1. C. perfringens (most freq)
2. C. septicum

Front 12

Pathogenesis: C. perfringens?

Back 12

1. Endogenous infections (rare)
2. Exogenous infections - wound contaminated w/ spore-soil (1 cause)
3. AC, septic abortus (rare)

Front 13

C. perfringens wound infection manifestations? (5)

Back 13

1. Foul discharge
2. Malignant edema
3. Gas-phlegmone
4. Myositis
5. Cellulitis

Front 14

Causes of endogenous C. perfringens infection? (4)

Back 14

1. Colon surgery + carcinoma
2. Gut rupture
3. appendicitis perforata
4. Post-amputation

Front 15

General symptoms: C. perfringens? (7)

Back 15

1. Malaise
2. Hypotonia
3. Fever
4. Vomiting
5. Toxemis
6. Shock
7. Death

Front 16

Necrotizing enterocolitis (NEC), caused by? (4)

Back 16

1. C. perfringens, TYPE C, B-toxin producing
2. Prevention: Type C toxoid immunization
3. *necrotic lesions jejunum, bloody diarrhea, peritonitis
4. via pork meat

Front 17

Incubation period: C. perfringens?

Back 17

1-3 days

Front 18

What strain of C. perfringens produces enterotoxin that causes FOOD POISONING?

Back 18

TYPE A C. perfringens (via meat)

Front 19

Type A C. perfringens causes?

Back 19

FOOD Poisoning
- *watery diarrhea, abdominal cramps
- 9-15hr incubation
- Detect: enterotoxin in stool
- Diagnosis: 10^5 colonies/g cultivaiton

Front 20

C. perfringens: DIAGNOSTICS? (7)

Back 20

(usually clinically)
1. Sample - necrotic tissue
2. Microscopically (Gram)
3. Anaerobic cultivation
4. Blood agar (double hemolysis)
5. Nagler rxn
6. Gas chromatography
7. Phage typing

Front 21

C. perfringens: PREVENTION? (4)

Back 21

Wound cleansing:
- efface necrotized material
- rinse w/ H202
- hyperbaric 02 treatment
- amputation

Front 22

C. perfringens: TREATMENT (antibiotics) (2)

Back 22

High dose AB
1. Penicillin G +/- clindamycin
2. Imipenem or Cephalosporins (III) - SEVERE CASES

Front 23

C. perfringens: TREATMENT (antitoxin)? (3)

Back 23

Polyvalent antiserum (1 to neutralize existing toxins)
1. C. perfringens antitoxins
2. C. septicum antitoxins
3. C. novyi antitoxins

Front 24

C. perfringens rod + spore shape?

Back 24

Front 25

C. tetani contains what type of spore?

Back 25

Terminal spore

Front 26

C. tetani characteristics? (6)

Back 26

1. GPR obligate anaerobe spore forming
2. Terminal spore
3. Peritrichous flagella + swarming
4. B-Hemolytic
5. Mild gas production
6. Neurotoxic

Front 27

C. tetani virulence factor?

Back 27

EXOTOXIN = tetanospasmin

Front 28

Effect of C. tetani exotoxin tetanospasmin?

Back 28

1. Enhances ACh effect --> *tetany
2. Exotoxin --> blocks inhibitory Renshaw interneurons from releasing GABA + glycine (CNS)

Front 29

C. tetani loci? (3)

Back 29

1. Soil + dust
2. Animal feces
3. Gut normaflora (sometimes)

Front 30

C. tetani: port of entry? (5)

Back 30

1.injury
2. burn + deep wounds
3. umbilical wounds
4. abortion
5. surgery, injections, ointments
(exogenous infections)

Front 31

Incubation period: C. tetani?

Back 31

4d-several weeks (LONG

Front 32

Latency of spasms: C. tetani?

Back 32

5-7d

Front 33

Clinical findings: C. tetani? (7)

Back 33

1. Lockjaw
2. Spasms
3. Hydrophobia
4. Respiratory dysfunciton
5. Opisthotonus (dorsal mm. sustained spasm)
6. Risus (facial mm. spasms)
7. Fully concious

Front 34

Localized type of C.tetani?

Back 34

Neonatal tetanus (entry: umbilical stump)

Front 35

C. tetani: Diagnosis? (4)

Back 35

1. Clinical symptoms
2. Anaerobic cultivation
3. Direct smear
4. Animal inoculation

Front 36

C. tetani: PREVENTION?

Back 36

DPTa (dipetheria, pertussis, tetanus, acellular)
- combined vaccine containing toxoid
- active immunization

Front 37

C. tetani types of treatments? (4)

Back 37

1. Symptomatic
2. Toxoid recall injection
3. Antitoxin
4. Antibiotics

Front 38

C. tetani: Symptomatic therapy? (5)

Back 38

1. Surgical debridement (no hyperbaric 02)
2. Cleansing wounds
3. Muscle relaxants
4. Sedation
5. Assisted ventilation

Front 39

C. tetani: Toxoid recall injection therapy?

Back 39

Toxoid vaccine + antitoxin iv

Front 40

C. tetani: Antitoxin therapy?

Back 40

Treat for those born before 1941, give before toxin is fixed in nerves

Front 41

C. tetani: Antibiotic therapy?

Back 41

Penicillin G

Front 42

How do you treat elderly C. tetanus infected patients?

Back 42

1. Toxoid vaccine (*slow immunity development)
AND
2. Antitoxic serum (to provide fast therapy)

(booster shot + antitoxic serum)

Front 43

C. botulinum characteristics? (5)

Back 43

1. GPR obligate anaerobe spore forming
2. Flagella (+)
3. Subterminal or central pore
4. High gas production
5. Loci: everywhere, maybe gut flora

Front 44

C. botulinum: CULTIVATION?

Back 44

Blood agar + anaerobic

Front 45

C. botulinum virulence factors?

Back 45

EXOTOXINS (A-H; A,B,E, F = human pathogens)

Front 46

C. Botulinum exotoxin mech?

Back 46

1. Neurotoxin (circ --> nerve endings --> *flaccid paralysis)
2. Heavy chain - binds motor endplate
3. Light chain - endocytosed --> cleaves SNAREs = block ACh vesicular release (no fusion)

Front 47

Toxic dose of C. tetani and C. botulinum?

Back 47

C. tetani = 0.0001 ug (mouse lethal dose)
C. botulinum = 1-2 ug lethal

Front 48

C. botulinum antigens? (2)

Back 48

1. Same O-AGs (somatic)
2. Different H-AGs (flagellar)

Front 49

Pathogenesis: C. botulinum?

Back 49

1. Toxicosis (foodborne botulism)
2. Wound botulism
3. Infant botulism

Front 50

Toxicosis (foodborne botulism)?

Back 50

meats/tin cans --> entry --> 3hrs to 1-2d latency --> gut absorbs toxin --> circulation = toxaemia

Front 51

Neonatal botulism?

Back 51

Spores in honey --> colonization in GI of infants < 1 year --> weakness, floppy baby, sudden death syndrome

Front 52

Inhalation of botulism can be used as a?

Back 52

Biological weapon

Front 53

Clinical symptoms: C. botulinum? (5)

Back 53

1. Double vision (initial symptom, due to brain nerves blocked)
2. Speech+swallow disorders
3. Ptosis (drooping lower eyelid)
4. Respiratory paralysis (-->*death)
5. Cardiac arrest

Front 54

Diagnostics: C. botulinum?

Back 54

Toxin detection w/ animal inoculation:
- food sample
- blood
- stool

Front 55

C. botulinum: TREATMENT? (3)

Back 55

1. Trivalent antitoxic serum (A, B, E) (-->*toxin neutralization)
2. Ventilation (100d, symptomatic)
3. Infants - pencillin 10-20MU/d

Front 56

C. difficile characteristics? (6)

Back 56

1. GPR obligate anaerobe spore forming
2. Motile
3. Central spore
4. Resistant to many antibiotics
5. Nosocomial pathogen (primarily)
6. gut normaflora

Front 57

What is the most freq agent causing nosocomial diarrhea?

Back 57

C. difficle

Front 58

What does C. difficle cause? (2)

Back 58

1. Pseudo-membranous colitis
2. Diarrhea

Front 59

C. difficle virulence factors?

Back 59

1. Enterotoxin - toxin A (-->*watery diarrhea)
2. Cytotoxin - toxin B (-->*colon wall destruction)

Front 60

Pathogenesis: C. difficile

Back 60

1. Endogenously - via gut normaflora (due to antibiotics effacing normaflora --> *overgrowth of C. difficle)
2. Exogenously - nosocomial infection --> *diarrhea

Front 61

C. difficile: TREATMENT induced resistance?

Back 61

PROLONGED TREATMENT resistance build up (i think)
1. Clindamycin
2. Cephalosporin
3. Fluoroquinolone

Front 62

C. difficile: THERAPY?

Back 62

1. Vancomycin
2. Metronidazole
3. Bacitracin

Front 63

C. difficile: DIAGNOSIS?

Back 63

1. endoscopy
2. CCFA, blood agar
3. Phage typing
4. Toxin detection (ELISA, latex agglutination,PCR)

Front 64

What clostridum spp. is resistant to ethanol and soap needs to be used instead?

Back 64

C. difficile

Front 65

Which ribotype produces the binary toxin of C. difficile?

Back 65

027 ribotype (A,B toxin with 027 = most lethal)

Front 66

Dysbacteriosis?

Back 66

disease caused by an imbalance of the normal flora
(i.e. C. difficile infections)

Front 67

Category A bioterrorisim agents? (4)

Back 67

1. B. anthracis
2. C. botulinum (toxin)
3. Yersinia pestis
4. Francisella tularensis
etc..

Front 68

Category B bioterrorisim agents? (6)

Back 68

1. Brucella spp.
2. Staphylococcus aureus (enterotoxin B)
3. E. coli (O57:H7)
4. V. cholerae
5. Shigella spp.
6. Salmonella spp.