L9 - Clostridium Enterotoxic

Clostridium is Gram-__________

positive

Clostridium is what shape?

rods + bacillus

Clostridium growth is _____________, irregular colonies form on plate, and are ___________ on blood agar

anaerobic, hemolytic

in terms of transmission, Clostridium is __________-forming

spore

in terms of disease symptoms, Clostridium is _______-producing

toxin

Clostridium can be found in sources that are _____________ (like soil), or ______________ (like intestine)

exogenous, endogenous

what are 3 predisposing factors that Clostridium can cause?

1. distruption of normal gut microbiota

2. sudden change in diet

3. disease can also form from ingestion of preformed clostridial toxins

what are the 4 main virulence factors of Clostridium?

1. toxins

2. spores

3. surface proteins --> mediate adhesion to host cells

4. surface-associated structures --> pilus, flagellum

_________ made by Clostridium are resistant to drying, heat, and disinfectants, and their vegetative cells are ___________

spores, anaerobic

which 5 species of Clostridium are enterotoxic?

1. C. perfringens

2. C. difficile

3. C. colinum

4. C. spiroforme

5. C. piliforme

Clostridium ______________ = most important clostridial disease in domestic animals

- has 5 toxin types --> A-E

perfringens

Clostridium perfringens has high ___________ to different host species, and will use its conjugative plasmids to infect various species

adaptability

C. perfringens is harbored in the ___________ of normal, healthy animals, and on its own won't cause disease

intestine

when does disease occur resulting from C. perfringens?

when conditions change to favor its overgrowth + toxin production

____________ is a risk factor for enterotoxaemia (aka conditions improve for overgrowth of C. perfringens) in the following 2 pathways:

1. ____________ --> reduced digestion --> more undigested material reaches intestine --> provides rich medium for bacterial growth + toxin production

2. ___________ --> reduced intestinal motility --> bacteria are retained longer + toxins have more time for absorption

overeating

in patients that are _________ in age, β-toxin-mediated diseases are favored

young

in patients that are _____ in age, ε-toxin mediated diseases are favored

old

what are the 6 main toxins that promote overgrowth of C. perfringens?

1. α-toxin --> Cpa or phospholipase C

2. β-toxin --> Cpb

3. ε-toxin --> Etx

4. ɩ-toxin --> Itx

5. C. perfringens enterotoxin --> Cpe

6. necrotic enteritis toxin B --> NetB

which toxin:

- phospholipase C

- acts on cell memb, hemolytic, lethal

α-toxin

which toxin:

- pore-forming

- CNS clinical signs

- trypsin sensitive

β-toxin

which toxin:

- secreted as a pro-toxin --> intestinal proteolytic enzymes --> activation

- deemed by CDC Select Agent List as the most toxic toxin

ε-toxin

which toxin:

- targets skeletal muscle

iota-toxin

what is a minor toxin that binds to cholesterol + forms pores --> causes cell death

Perfringolysin O

toxin Type ____:

- young ruminants --> fatal necrotizing abomasitis

- chickens --> necrotic enteritis

- neonatal foals, pigs, dogs --> hemorrhagic enteritis/diarrhea

A

toxin Type ____:

- lamb dysentery --> newborn lambs

- colostrum --> antitrypsin --> breaks trypsin --> protects β-toxin

B

toxin Type ____:

- newborns --> absence of microbiota

- chickens --> necrotic enteritis

- struck --> intestinal toxemia --> sudden death in older sheep

C

toxin Type ____:

- found in older lambs and goats EXCEPT NEONATES

- "overeating disease" or "pulpy kidney disease"

- enterotoxaemia

D

toxin Type ____:

- hemorrhagic enteritis in calves

E

how should you diagnose C. perfringens in the lab?

1. isolation --> blood agar anaerobically, heat to 80 degrees C, spores will survive

2. staining --> Gram, Wright's, Giemsa

3. PCR

4. ELISA --> for toxin identification in the stolls of infected dogs or cats

what are 3 ways to control C. perfringens?

1. active immunization

2. passive immunization

3. abx

___________ ____________ infection = known to cause antibiotic-associated diarrhea in humans

Clostridium difficile

Clostridium difficile infection (CDI) can be seen in:

- ___________ foals --> hemorrhagic necrotizing enterocolitis

- ____________ horses --> nosocomial diarrhea + typhlitis

neonatal, adult

CDI's are worse in species with ___________ large intestines like horses, rabbits, swine

enlarged

a CDI is common following the intake of what?

an antimicrobial

lab diagnosis for CDI?

____________ __________ = prevalent in quails + poultry

Clostridium colinum

_____________ ____________ = seen in rabbits with typhlocolitis

Clostridium spiroforme

___________ ___________ = seen in laboratory animals (mice) and foals, and causes Tyzzer's disease

Clostridium piliforme

C. piliforme can be caused by __________ __________ in foals, and is 50-100% fatal

hepatic necrosis