MICROBIO 5.5

Clostridium

Clostridium

Bacteria that survives via endospores

Endospore

Dormant/metabolically inactive structure of clostridium triggered by environmental stressors (e.g. extreme temperature, starvation, drying, radiation)

NOT reproductive structure

Sporulation

How endospores are made

Steps of sporulation

1. cell copies DNA

2. bundles DNA with ribosomes and enzymes needed for vegetative cell

   1. bundle = “core”

3. surrounded by heat & chemical resistant layer that allow endospore to persist in extreme environment

4. when endospore forms, cell lyses (dies) & releases

5. once environment becomes hospitable again, it turns into vegetative cell & resumes metabolism

Botulism

Flaccid paralysis by inhibiting release of stimulatory neurotransmitter; no stimulatory neurotransmitters are released, and muscles CANNOT CONTRACT (always relaxed)

What is responsible for botulism?

Clostridium botulinum, which secretes the paralyzing “botulinum neurotoxin”

Clostridium gram status

Positive

Clostridium shape

Bacillus (rod)

Clostridium oxygen requirements

Anaerobe

Toxemia

Blood poisoning by neurotoxins in blood

Three types of botulism

1. Infant botulism

2. Foodborne botulism

3. Wound botulism

Infant botulism

• Occurs in <1 yrs old

• Caused when endospore from air, dust, food (e.g.) honey are ingested

• pH of GI tract allow endospore to germinate & release neurotoxin

• Signs: constipation, muscle weakness, paralysis, weak cry, drooping eyelid, nausea, vomiting

Foodborne botulism

• Caused by improperly canned vegetables

• Can be prevented by proper canning and cooking

• Signs: Difficulty swallowing, speaking or breathing; altered vision, drooping eyelid, nausea, vomiting, paralysis

Wound botulism

• Caused by bacteria entering through a break in the skin

  • Usually linked ot injecting heroin

• Signs similar to foodborne

Treatment for botulism

• antitoxin —> compete with toxins binding in body

• antibiotics —> try to eliminate Clostridium botulinum

• respiratory support until muscle functions or breathing

Uses of the botulinum toxin IRL

• Botox —> smooth wrinkles through muscle relaxation

• Migraine headache —> toxin injected near nerves that cause headache

Tetanus

AKA Lockjaw; SPASTIC paralysis by inhibiting release of inhibitory neurotransmitter; no stimulatory neurotransmitters are released, and muscles CANNOT RELAX (always contracted)

What causes tetanus?

Clostridium tetani, which releases neurotoxin tetanospasmin.

Where is tetanus found?

Soil dust, animal species

Signs of tetanus

• muscle spasm

• drooling

• sweating

• irritability

• respiratory failure an be caused due affect to muscles that control breathing

Treatment for Tetanus

• NO CURE

• Preventable by vaccination

Gas gangrene

Tissue necrosis in extremity caused by Clostridium Perfringen (releases perfringolysin)

How does Clostridium Perfringen cause necrosis?

Clostridium Perfringen PERFORATES (forms pores) in cell membranes causing uncontrolled ion flux & cell lysis

Necrosis

Tissue death in a live organism; typically from a loss of blood flow

Extremity

Limb

Where is Clostridium Perfringlolysin found?

Water, soil, intestinal tract of animals

How does gas gangrene typically ocur?

Deep wound forms an anaerobic environment

Diabetics & individuals with decreased blood flow have increased risk

Signs of gas gangrene

• Pain

• Swelling, Fever

• Darkening skin

• Odor

• Drainage

• Gas bubbles under skin

• Can lead to shock, coma, or death

Treatment for gas gangrene

• antibiotics

• debridement

• hyperbaric oxygen therapy

Debridement

Amputation of necrotic tissue

Hyperbaric Oxygen Therapy

Oxygenates and helps decrease anaerobic envt

Clostridiodes difficiles AKA C. Diff

Clostridium that causes antibiotic-related infectious diarrhea and deadly colitis (colon inflammation)

Highest healthcare acquired infection (HAI)

How do infections with C. diff usually occur?

Antibiotic usage decreases colon’s normal microbial flora; C. Diff has less competition for nutrients

Once C. diff begins to proliferate (multiply), toxin is secreted and diarrhea and inflammation in colon is caused

Transmission route of C. diff

Fecal-oral

C. diff precautions

Contact & standard

C. diff infection symptoms

• mild/moderate diarrhea (causing dehydration)

• colitis

  • can lead to bowel perforation, sepsis, and hemorrhage

C. diff diagnosis

• culture from stool samples

• molecular methods to detect bacteria genes and enzymes

C. diff treatment

• rehydration

• antibiotic

• fecal transpant

  • stool from screened & healthy donors

  • placed into colon of patient

  • microbial flora repopulates patient colon & competes for resources