Anaerobic bacteria Flashcards
Where can you find anaerobic bacteria in animals?
GI tract
T/F: Anaerobic bacteria can be BOTH endogenous and exogenous
TRUE
found in GI tract and in the environment
Tetanus toxin is a neurotoxin and acts by inducing ____
Inhibition of neurotransmittors
Which of the following statements is correct?
- Tetanus toxoid is an inactivated toxin
- Teatnus toxoid is an inactivated bacterin
3, Tetanus toxin directly affects muscles - Tetanus occurs after ingestion of toxin
1
The main mode of transmission of Botulism is ______
Ingestion of toxin (not the bacteria itself)
*rarely occurs from wound infection
What is a major symptom of tetanus?
Spastic paralysis
What clinical signs will you see in a cow suffering from Botulism?
Drooping ears, drooling, tongue out
Eventually they die from respiratory failure
What toxin does C. perfringens make and why is it important?
Epsilon toxin
Very lethal - considered a bioterrorism substance
What spps of clostridium are neurotoxic?
C. botulinum
C. tetani
C. perfringens
What spps of clostridium are histotoxic?
C. chauvoei
C. septicum
C. novyi
C. perfringens
What spps of clostridium are enterotoxic?
C. perfringens
C. difficile
What neuro transmitters does C. tetani inhibit?
Gaba and glycine
Causes SPASTIC paralysis
What neuro transmitters does C. botulinum inhibit? What kind of paralysis does it cause?
Acetylcholine
Flaccid paralysis
Who are most susceptible to C. tetani?
Horses > humans > other animals
If are called to a farm for a “wooden horse”, what do you suspect is the cause and what do you look for?
C. tentani: causes spastic paralysis, lock jaw, and stiff limbs
Look for a wound! This is where the bacteria are replicating and producing toxins
Who typically gets ascending tetanus and what is it?
Seen in dogs and cats
The toxin ascends up limbs from the affected wound - causing paralysis of one-two limbs at a time
Who typically gets descending tetanus and what is it?
Seen in horses and humans
Toxins enter the bloodstream via wounds. Paralysis will begin in the head and neck and then affect all limbs
T/F: Culture and serology are good methods of diagnosing C. tetani infections
FALSE
Dx is via clinical presentation. Can also perform a diff quick or gram stain from smear of wound - may see gram positive endospores
What is used to make the tetanus vaccine?
C. tetani TOXIOD - inactivated toxin
How do you treat tetanus?
Anti-toxin
Anti-tetanus equine serum (sometimes results in anaphylactic reactions)
Wound debridement to prevent further toxin release
Supportive care (muscle relaxers etc)
T/F: Botulinum toxin is a highly potent endotoxin
FALSE - EXOtoxin*** very potent
What deficiency in cattle increases their susceptibility to contracting botulism?
Phosphorus deficiency
It causes PICA - cattle will start to eat anything/everything - including bones etc of infected carcasses
What a tell tale signs a bird has botulism?
Flaccid paralysis and protrusion of the 3rd eyelid**
T/F: Botulism is an easy to diagnose
FALSE
How do you prevent botulism?
Good quality feed!!
Which of the following clostridium does NOT exert its effect through histotoxic activity?
C. chauvoei
C. septicum
C. perfringens
C. botulinum
C. botulinum = neurotoxic
Black leg is caused by?
C. chauvoei
Enterotoxic clostridium include all of the following except:
C. difficile
C. perfringens
C. botulinum
C. colinum
C. botulinum
A fast, practical and reliable test to diagnose black leg in cattle is…?
Direct fluorescent antibody staining of affected tissue
What clostridium spps causes ulcerative colitis in quails?
C. colinum
Which of the following is incorrect about C. piliforme?
- causes Tyzzers dz
- Is a gram negative clostridium
- Dx by anaerobic culture
- Liver necrosis is a common lesion
3 - C. piliforme is an OBLIGATE INTRACELLUR pathogen so it can not be cultured
T/F: All clostridium spps are gram positive
FALSE
C. piliforme is the ONLY gram negative clostridium
What do histotoxic clostridium spps cause?
Tissue damage - necrosis - usually localized infections
Who are the most common hosts of histotoxic clostridium spps?
What are the histopathic clostridium spps?
Farm animals
C. septicum
C. chauvoei
C. noyvi
C. perfringens
T/F: Animals can ingest toxins and get Black Leg
False
Animals ingest SPORES, that will get stored in muscle –> then when a traumatic injury occurs they will become vegetative and produce toxins
What process causes gas accumulation that creates distinctive lesions in patients with histotoxic clostridium infections?
Fermentation
gas accumulation - has distinctive smell, and causes necrosis
T/F: Black leg can occur due to an exogenous infection
TRUE
exogenous and endogenous
What spps of clostridium causes black leg in cattle and sheep?
C. chauvoei
What are the clinical signs of black leg in sheep and cattle? Can it be treated?
Gangrene necrosis, hemorrhagic necrosis, with gas accumulation, systemic toxemia. Acute fever
100% mortality - no tx
What animals are most susceptible to C. chauvoei?
Young, healthy calves at pasture (most commonly in summer)
What does C. novyi - Type A cause?
“big head” in Rams
Gangrene necrosis
What does C. novyi Type B cause?
Black Disease - infectious necrotic hepatitis
**animals are predisposed if they have had a liver fluke
What do C. hemolytica (C. novyi type D) cause?
liver damage and bacillary hemoglobinuria in cattle and sheep
What spps of clostridium causes malignant edema in pigs and horses?
C. sepcticum
T/F: C. septicum infections can occur exogenously or endogenously
TRUE
How do you treat malignant edema?
Need to perform surgical debridement to remove necrotic tissue and any toxin releasing material
What procedures increase the risk of infection with C. septicum?
IM injections in horses, shearing, docking, lambing in sheep
What diseases does C. septicum cause and in who?
Malignant edema = pigs and horses
Braxy = abomasal edema in sheep
Necrotic dermatitis = chicken
What is the best dx test for C. septicum infections?
Direct fluorescent antibody staining (DFA)
*should be performed by a reference lab
In house - can perform a gram stain on a muscle impression smear
T/F: Vaccines for C. septicum diseases can be made by using a toxoid or a bacterin
TRUE
If you catch a malignant edema infection quickly in a horse, what medicine would you start it on right away?
Penicillin
T/F: All C. perfringens has alpha toxins
TRUE
How does an animal get enterotoxemia?
Bacteria produce toxin in the GI tract –> then it is absorbed into the bloodstream
*C. perfringens and C. difficile
What does C. perfringens Type C cause?
necrotizing enteritis in piglets
What does C. perfrigens Type D cause?
enterotoxemia in Sheep and Goats
aka “pulpy kidney dz” or “over eating dz”
What clinical signs are seen in “over eating dz”?
Fluid distended intestine with petechial hemorrhages on serosal surfaces, ***focal, symmetrical encepholomalacia, pulpy kidney from increased autolysis post mortem
*acute death due to hemorrhage and hypovolemic shock
What causes “over eating dz”?
Feeding high grain diets to sheep and goats –> causes a change in the gut pH that allows C. Prefringens to thrive and produce toxins
What dx tests should be performed if you suspect C. septicum?
Anaerobic culture from intestine and toxin genotype test
What tx can be provided for a sheep with pulpy kidney dz?
hyperimmune serum (if infection is caught early enough)
Antimicrobial therapy is NOT EFFECTIVE
How can you prevent pulpy kidney dz?
Vaccination and avoiding sudden change in diet
T/F: C. difficile causes entercolitis in humans
True!
as well as - horses, pigs, cats, dogs, etc
When do C. difficile infections occur?
After antimicrobial treatments!
Antimicrobials will change the intestinal flora - allows for C. difficile to take over - multiply - produce toxin
What is dysbiosis?
Microbial imbalance
**how C. difficile infections occur
What are the virulence factors of C. difficile? Why are they important?
Tox A and Tox B
They synergistically destroy enterocytes
Are used for detection in dx via ELISA
How do you treat enterocolitis caused by C. difficile?
STOP antimicrobials (since this is an infection that occurs due to antimicrobial effect on normal flora)
Probiotics
no clindamycin in horses
- human medicine is researching fecal transplants
What spps of Clostridium causes enterotoxemia and explosive dhr in bunnies 4-8wks of age?
C. spiroforme
What antimicrobials should be avoided in rabbits to prevent C. spiroforme infections?
Lincomycin, clindamycin, erythromycin
these induce clostridium related enterotoxemia
What bacteria cause Foot Rot in cattle?
What bacteria cause Foot Rot in sheep?
Cattle: Fusobacterium necrophorum
Sheep: Fusobacertium necrophorum AND Dichelobacter nodosus
What diseases does Fusobacterium necrophrum cause in cattle? (3)
- Foot rot
- Calf Diptheria (necrotic laryngitis)
- Liver abscesses
Gram negative, non spore forming anaerobes are commensals on…?
Mucus membranes and skin
T/F: Gram negative, non spore forming anaerobes are not commonly found in “mixed” bacterial infections
FALSE
They are often in mixed bacterial infections
T/F: The vaccine for foot rot in cattle is the same vaccine used in sheep
FALSE
Cattle foot rot vax uses Fusobacterium necrophorum
Sheep foot rot vax uses dichelobacter nodosus
