Anaerobes

Question 1

Predisposed to Anaerobic Infections

Answer 1

• Skin and mouth trauma
• Surgery in GI or GU tract
• Vascular stasis

Question 2

Clues of Anaerobic Infections

Answer 2

• Stank/farty
• Necrotic tissue
• Black exudate, red fluorescence to long wave UV light

Question 3

Clostridium/Clostridioides: Basics

type, where, infections

Answer 3

Type: spore-former, but can be rarely seen
Habitat: soil, water, sewage
- Normal micro flora in GI tract
- Mostly harmless saprophytes

Infections:
- Tetanus (C. tetani)
- Botulism (C. botulinum)
- Gas gangrene (C. perfringens, C. septicum)
- Diarrhea and colitis (C. perfringens, C. difficile)

Question 4

Tetanus: Basics

trans,symtpmos

Answer 4

Transmission: breaks in skin, dirt, burn wound, compound fractures, punctures
Symptoms: lockjaw, drooling, spasms, cardiac, spastic paralysis
- Localized: musculature at site of infection
- Neonatal: umbilicul stump, high mortality

Question 5

Tetanus: Virulence

Answer 5

Tetanospasmin: A-B toxin, heat labile neurotoxin, blocks neurotransmitters

Question 6

Tetanus: Treatment

Answer 6

Get rid of dead cells, immunoglobulin, vaccine, antimicrobials

• Cannot get rid of toxin since they’re already bound, just treat symptoms until nerve endings are regenerated

Question 7

Botulism: Basics

Answer 7

Symtoms: nausea, vomiting, descending muscle weakness, respir. paralysis, neurologic symptoms
Onset: day or two, contam. food

Four forms: foodborne, infant (most common), wound, inhale
- Infant: flaccid paralysis

Question 8

Botulism Toxin

Answer 8

Botlinum toxin: A-B, heat labile
- Nontoxic protein coat that protects neurotoxin as it passes through

Cleaves sites on synaptic fusion compex and SNARE proteins which mediates release of acetylcholine, which is a neurotransmitter
- Muscles cannot contract

Question 9

Botulism Treatment

Answer 9

Ventilatory support, eliminate organism from GI tract, no vaccine
- Antimicrobial therapy
- Antitoxins A, B, E

Question 10

Gas Gangrene

Answer 10

Clostridial myonecrosis: life threatening, soft tissue

Symptoms: intense pain, necrosis, shock, renal failure, death, gas in tissue from metabolic activity

• C. septicum commin in pts with colon cancer, leukemia, diabetes

Question 11

Gastroenteritis By Anaerobes

Answer 11

Transmission: contam. food, beef, poultry, gravy
- Precooked food not reheated properly

Toxin: produced after ingestion of microbe, sporulation

Symptoms: watery diarrhea, cramping, pain, no vomiting
- 24-48hr duration

Question 12

Clostridium Perfringens “Food Poisoning”

Answer 12

Contaminated food like raw meat
- Spores survive cooking
- Reheating does not kill
- Sporulate when you eat it, enterotoxin
- Diarrhea

Question 13

Other Anaerobe Treatments

soft tissue, foodborne

Answer 13

Soft tissue: aggressive treatment, debridement, high antimicrobials, hyperbaric oxygen chamber

Foodborne: self limiting

Proper care and food safety

Question 14

Colitis

symptoms, trans, toxin

Answer 14

C. difficile - antibiotic associated diarrhea (AAD)
- Leads to pseudomembranous colitis
- Antibiotics kill normal gut flora

Transmission: fecal-oral person to person
- Heat resistant spores, hospitals, nursing homes
- C. difficile toxins: enterotoxin A that stimulates cytokines, cytotoxin B that increases permeability of intestinal wall causing diarrhea

Question 15

Colitis Treatment

Answer 15

Antibiotic two rounds, second for spore relapse
- Microbiota transplant

Question 16

Other Anaerobic Bacteria: Basics

where, infections,

Answer 16

Habitat: nromal flora, oral, GI, GU, skin, depending on genus
Infections: mostly endogenous, polymicrobic