Clostridium, Actinomyces israelii, Nocardia asteroides, Aeromonas, Plesiomonas

Question 1

Describe the physical structure of Clostridium

Answer 1

G+ Rods, Usually Rounded Ends
Pairs/Short Chains
Sporulatin

Question 2

Describe the oxygen sensitivity of Clostridium

Answer 2

Anerobic

Question 3

Clinical presentation of Clostridium botulinum

Answer 3

18-24 hour incubation

Bilateral Cranial Nerve Palsies with Progressive Descending Flaccid Paralysis

Question 4

How do people die of Clostridium botulinum?

Answer 4

Involvement with heart or diaphragm

Question 5

Main sources of Clostridium botulinum infection?

Answer 5

Home-Canned Foods, Rarely commercial

Entry Woulds, like needles (botox, black tar heroin)

Question 6

How does Clostridium botulinum manifest in children?

Answer 6

Rapidly colonizes gut, replaces developing flora
Floppy Baby Syndrome
Caused by spores in honey

Question 7

Pathogenesis of Clostridium botulinum?

Answer 7

AB neurotoxin
- B binds neuron end plates, A blocks ACh release
No ACh = Flaccid Muscle Paralysis

Question 8

How does Clostridium botulinum block ACh release?

Answer 8

Cleaving synaptobrevin

Question 9

How is Clostridium botulinum controlled?

Answer 9

Use Antitoxin from CDC as early as possible

Question 10

Clinical presentation of Clostridium tetani

Answer 10

Rigid Paralysis

Eventually Death from Inability to Breathe

Question 11

Epidemiology of Clostridium tetani?

Answer 11

Spores in soil/feces

Introduces by fomites in skin

Question 12

How do neonates get Clostridium tetani?

Answer 12

Umbilical stump infection

Question 13

Pathogenesis of Clostridium tetani?

Answer 13

A-B neurotoxin, tetanospasmin

 - Absorbed at neuromusc. junction, retrograde transport to motor neuron
 - Binds irreveribly to and re-uptaken by presynaptic mem. of inhib neurons
 - Cleaves synaptobrevin, no GABA release

Question 14

How is Clostridium tetani controlled?

Answer 14

DTaP, Tdap

Question 15

What can you do for a tetanus patient?

Answer 15

Tetanus Immune Globulin antitoxin
avoid stimulation
Early tracheostomy to prevent laryngospasm suffication
Muscle Relaxants
Metronidazole

Question 16

Describe the presentation of Clostridium perfringens

Answer 16

Infected wound suppurating
Foul Discharge, Tissue Necrosis
Toxemia, Shock Death
Also – can present as food poisoning –> gut necrosis

Question 17

Epidemiology of Clostridium perfringens

Answer 17

Traumatic Tissue Injury, Esp if anaerobic conditions

Question 18

Why is Clostridium perfringens typically polymicrobial?

Answer 18

Other infection will produce the anoxic environemnt Clostridium perfringens requires

Question 19

Pathogenesis of Clostridium perfringens?

Answer 19

Extracellular enzyme secretions destroy tissue, allow invasion
- alpha toxin
- hyaluronidase, collagenase
- beta-toxin
- enterotoxin
Gas from ferm. causes tissue distention, compressed vessels

Question 20

What does alpha toxin do?

Answer 20

Its a lecithinase (phospholipase)

Question 21

How is Clostridium perfringens controlled?

Answer 21

Prompt surgical debridement

Question 22

How is Clostridium perfringens treated?

Answer 22

Metronidazole, Penicillin, and Clindamycin stop growth

Question 23

Clinical presentation of Clostridium difficile?

Answer 23

Usually following antibiotics
Watery Diarrhea early
Leukocytes penetrate connective tissue of bowel
- Form pseudomembrane

Question 24

Which anti-biotics are most prone to cause Clostridium difficile development?

Answer 24

beta-lactams, clindamycin

Question 25

Development of Clostridium difficile associated diarrhea requires what two things

Answer 25

1. presence of C diff | 2. disruption of native flora

Question 26

Who gets Clostridium difficile?

Answer 26

People on antibiotics or PPIs

Question 27

Normal influence of Clostridium difficile on the colon?

Answer 27

Important for T-reg development

Question 28

Most Clostridium difficile patients are infected where?

Answer 28

A Health Care Setting

Question 29

Pathogenesis of Clostridium difficile?

Answer 29

Enterotoxin (Toxin A) -- Fluid Acc | Cytotoxin (Toxin B) -- Kills gut epithelial cells

Question 30

How is Clostridium difficile controlled/treated?

Answer 30

``` Stop previous antibiotics if you can Replenish gut flora Vancomycin, Metronidazole Fecal transplant Fluid Replacement ```

Question 31

Physical structure of Actinomyces israelii

Answer 31

G+ | Branching, Fragmenting Filaments

Question 32

Oxygen sensitivity of Actinomyces israelii?

Answer 32

Facultative anerobes

Question 33

Actinomyces israelii colonies are in what shape?

Answer 33

Molar tooth

Question 34

Clinical presentation of Actinomyces israelii?

Answer 34

Swollen, pyogenic abscess with draining fistulae (lumpy jaw) "Sulfur granules" apparent in collected pus Common in face/neck, lungs, ab, skin

Question 35

How do people typically get Actinomyces israelii infection?

Answer 35

Tooth extraction or poor oral hygiene Thoracic inf from aspiration abdominal inf from perforated gut/appendix Foot from soil bacteria

Question 36

Who gets Actinomyces israelii?

Answer 36

IC patients

Question 37

How is Actinomyces israelii treated?

Answer 37

Surgical drainage of abscess | Parenteral Pen G for a few weeks

Question 38

Unique physical traits of Nocardia asteroides?

Answer 38

Actinomycete Shorter mycolic acids, partially acid fast aerobic, lives in soil

Question 39

Clinical presentation of Nocardia asteroides?

Answer 39

Lobar Pneumonia in Alcoholics or IC Lung abscesses Can spread to brain --> meningitis, brain abscess In foot from soil

Question 40

How do people get Nocardia asteroides infection?

Answer 40

Opportunistic infection | Lung aspiration of vomit

Question 41

How is Nocardia asteroides treated?

Answer 41

SxT

Question 42

Physical structure of Aeromonas hydrophilia, plesiomonas shigelloides?

Answer 42

G- Rod Fac. anerobe Motile

Question 43

Where are Aeromonas hydrophilia, plesiomonas shigelloides found?

Answer 43

Common Fish Pathogens Aeromonas hydrophilia - Fresh Plesiomonas shigelloides - Salt

Question 44

Clinical presentation of Aeromonas hydrophilia, plesiomonas shigelloides infection?

Answer 44

Gastroenteritis -- can be watery or blood and mucas Cellulitis from infected wounds Myonecrosis

Question 45

How do people typically get Aeromonas hydrophilia, plesiomonas shigelloides?

Answer 45

Infected food, water Tissue entry after trauma (fish-hook) SCUBA biofilms

Question 46

Pathogenesis of Aeromonas hydrophilia, plesiomonas shigelloides?

Answer 46

LPS, PG toxicity ACT toxin Pili grab onto gut epithelium

Question 47

How is Aeromonas hydrophilia, plesiomonas shigelloides controlled?

Answer 47

Avoid undercooked seafood

Question 48

How do you treat Aeromonas hydrophilia, plesiomonas shigelloides?

Answer 48

SxT, Tetracycline