Week 3 - Bacillus Flashcards
Bacillus anthracis is ______
Bacillus cereus –> not _____
Bacillus thuringiensis –> not _____
Bacillus licheniformis
zoonotic, pathogenic, pathogenic
Bacillus is _____, gram ______.
Large, positive
Bacillus produces _________. When is an un-ideal environment, it is still able to produce _______ which makes them _______, especially in the ____.
endosopores, spores, resistant, soil
Bacillus is an ______ bacteria.
Aerobic
Bacillus grows on ___-_____ media
non-enriched
Bacillus is _____.
motile
Bacillus is Catalase _____, Coxidase ______.
positive, negative
Majority of Bacillus are _____-_______.
non-pathogenic
Bacillus anthracis causes ______ in domestic animals, including ______.
anthrax, humans
Bacillus licheniformis: produces ______ ______ in cattle and sheep
sporadic abortions
alpha toxin is almost common for all the C. perfringes and it has similar biological activities
Bacillus Morphology
_____, in pairs or ____ chains
Rods, long
Bacillus is ______ distributed in the environment
- Endospores can survive ____ than ___ years.
- Resist _______, ____ temperatures, and chemical _______
widely, more, 50, desiccation, high, disinfectants
What is this an image of?
Piece of paper with substrate. When this paper is contact with bacteria sample, the bacteria have the oxidase enzyme, transform or change the color of ?. Tetramthyl-p-…. This chemical compound accepts electrons that are given by oxidase. When this happens, this chemical compound changes from white to blue. The bacillus are negative, so you will not see any change of color here.
Bacillus anthracis
Colonies up to __ mm in diameter, ___, ___, _____ appearance (_____ head at edge of the colony)
No _____.
5, flat, dry, greyish, medusa, hemolysis
What bacteria is this?
What can be seen when you look closely?
Bacillus anthracis
The spore (not stained).
Rod shaped, long chain
Rectangular shape with sharp ends on each side of the bacteria.
What can be seen here?
Bacillus anthracis
No hemolysis seen on blood agar
What can be seen here?
Bacillus anthracis
Medusa head; very characteristic morphology
Bacillus cereus
Colonies similar to ____ ______ but larger with a _____ tinge _______ around the colony
B. anthracis, greenish, Hemolysis
What can be seen here?
Bacillus cereus
Similar morphology to bacillus anthracis
What can be seen here?
Bacillus cereus
Hemolytic (hemolysis of RBC). This is not present in bacillus anthracis
Bacillus licheniform
Colonies are ____, ____, _____ and strongly ____ to the agar
dull, rough, wrinkled, adherent
Spore is rich in _______.
What is important in the formation of spore?
calcium,
Can survive for a long period of time when they are in the spore (Can survive for up to 50 years).
soil rich in ca and nitrogen.
What can be seen here?
Bacillus licheniform
Colonies have rough/dry surface. They attach to the surface of the?
Clinical manifestation of B. anthracis in cattle, sheep.
Very susceptible.
Can develop acute or peracute septicaemic antrhax
Clinical manifestation of B. anthracis in pigs?
Acute anthrax with oedematous swelling in pharyngel region and intestine
Clinical manifestation of B. anthracis in horses?
Subacute anthrax with localized edema, septicemic colic
Clinical manifestation of B. anthracis in humans?
Contact (skin), spore is inhaled, or enters intestine via ingestion.
Clinical manifestation of B. cereus in cattle?
Sometimes can produce mastitis, but is not very common
Clinical manifestation of B. cereus in humans?
Food poisoning, eye infections
Clinical manifestation of B. icheniformis in cattle, sheep?
sporadic abortion; not very common
Describe the epidemiology of Bacillus.
Endospore can survive for long period of time in the soil that are alkaline or contain Ca/N. These spores can contaminate the pasture grasses; the soil, when animals are infected OR when animals die on farm and are buried. –> When it rains or for some reason the water from underground rises to the surface and carries spores –> spores are ingested/inhaled/contact with skin.
Describe the pathogenesis of Bacillus
Capsule provides resistance to phagocytosis
Toxins components: Protective antigen (helps bacteria binding moiety), edema factor (toxic for ?) and lethal factor.
Neutrophils is the target of the edema factor.
Macrophages, dendritic cells neutrophils and some epithelial and endothelial cells are
the target of the lethal factor
Describe the clinical signs of Bacillus
Clinical signs: Cattle and sheep are more susceptible and develop fever, depression, congested mucosae and petechiae, eventually abortion.
When animals die, it is not recommended to do necropsy. Usually report it to health agencies must dispose the body properly.
Describe the lesions caused by Bacillus
Lesions: rapid bloating, incomplete rigor mortis, ecchymotic hemorrhages and oedema, blood is dark, unclotted blood and blood stained fluids in cavities, extremely large soft spleen (main characteristic in cattle).
How do you diagnose Bacillus?
- Presence of unclotted blood in mouth, nostrils and anus.
- Do not open the carcasses.
- Blood sample or fluids Gram staining
- Bacterial culture Blood agar: 37C, 24-48h.
- PCR
- Ascoli test, precipitation or gel diffusion
How do you treat cases of Bacillus?
- Penicillin, oxytetracyclin
How do you control Bacillus in endemic regions?
Annual vaccination –> Sterne strain, live vaccine, the spores convert in non-encapsulated avirulent
vegetative organisms.
How do you control Bacillus in non-endemic regions
- Avoid movement of animals
- Personnel must wear PPE
- Foot baths (formalin + peracetic acid)
- Immediate disposal of carcasses
- Lock all buildings and fumigate with formaldehyde)
What can be seen here?
Characteristic lesion caused by Anthrax in humans
What is this graphic depicting?
Inhalation of spore/ingestion/by flies or mosquito that carries bacteria
What can be seen here?
Contaminated animal dies –> bacteria starts to produce spores –> spores in ground can be transported during rainy season to another farm.
Fumigate with bacteria, 45 degrees Celsius
Characteristics of Clostridiums
• ______ or ______ ____ rods.
• Produce ______. The ___, ____ and ____ of the endospores can be used for species differentiation.
• More than ___ species but less than __ are pathogenic.
Straight, slightly, curved, endospores, size, shape, location, 100, 20
rods can be in pairs; ends are more rounded.
Clostridial cultures typically emit ____ ____
putrid odors
Tissue degradation produces a lot of gas. Usually different type of volatile fatty acids, which produces this odor.
Peptide catabolism is the?
most common mode of energy production by clostridiums
What is this graphic showing?
Spore at the end of the rod. When spore is located on one end, we can characterize the spore as a terminal spore. If the spore is in the center, is it called central spore.
If between center and end it is subterminal.
Anthracis = center
Clostridia are ______, they constitute part of the ______ _____ flora and some may be
sequestered as _______ in _____ or ____. Sequestered endospores, if _____, may produce disease
saprophytes, normal intestinal, endospores, muscle, liver, activated
Closridia are _____, gram _______ ___
large, positive, rods
Clostridia produces ________
endospores.
Clostridia are ________, catalase ______, and oxidase ______.
anaerboci, negative, negative
Clostridia are _____, except C. perfringens.
motile
Clostridia requires ______ media to grow.
enriched
Colonies of C. perfringens are surrounded by zones of _______ _______.
double, hemolysis
Clostridia is present in?
soil, alimentary tracts of animals, and feces.
Clostridia pathogens can be grouped according to?
The mode and sites of action to their potent exotoxins:
1. Neurotoxic clostridia
2. Histotoxic clostridia
3. Enteropathogenic and enterotoxemia-producing clostridia
Clostridia produces ______ _____ of disease in ____ animal species.
diverse forms, many
The Neurotoxic clostridia are?
The Histotoxic clostridia are?
The Enteropathogeic and eneterotoxaemia-producing clostridia are?
The Atypical clostridia are?
C. tetani
Normally affects animals through any kind of trauma/wound.
Genes = plasmids
Antigenic type = one type
C. botulimum
Infection is mainly through ingestion of bacteria/spore/toxin.
Genes = chromosome, plasmid, or bacteriphage (depending on type of C. botli from type A-G).
Antigenic type = seven
Describe the serological types of Clostridium tetani.
_____ serologic types
• Based on ______ antigens
• Sometimes related to _______ strain ____
• TeNT is antigenically _____ (meaning ?). HUGE IMPORTANCE FOR VACCINE (b/c?)
Ten, flagellar, geographic, origin, uniform, toxin never changes; very useful to produce immunity in the animal b/c toxin never changes and is exactly the same and the toxin is what produces the disease, with one vaccine we are protected forever unless we sustain an injury from metal or? then we get a booster.
Toxin is normally treatd with formalin, which inactivates toxin, once inactivated you add adjuvant to vaccine and give to the animal. Most common adjuvant for tetanus vaccine is aluminum dioxide which produces a lot of pain.
Aluminum advances antigen presentation and releases the antigen very slowly.
Clostridium tetani is widely distributed in ____ and is often transient in the ____
soil, intestine
Occurrence of tetanus is linked to the introduction of the ____ into ____ tissue
spore, traumatized
How can you contract tetanus?
• Contaminated syringes!!!!
• Penetrating nail wounds of the foot
• Barnyard surgery
• Use of rubber bands for castrating and docking sheep
• Ear tagging infections
• Shearing wounds
• Post-partum uterine infections
• Peri-natal umbilical infections
• Small animal fights
May see clincial signs of tetanus but no signs of injury or lesions.
Tetanus is a _______ intoxication characterized by ?
Neuroparalytic, tonic-clonic convulsions
Tetanus is due to ?
protein neurotoxin
Who is susceptible to tetanus?
All mammals are susceptible (varying degrees)
• Horses and humans, ruminants, and swine more susceptible
than carnivores
• Poultry highly resistant
• In all animals, the mortality rate is high
When animals are sick or exhibiting clincial signs, normally the mortality is high
Tetanus toxin is called
tetanospasmin
Zinc endopeptidase binds to the _____, which release _______ _______ ____ (?) and ____, the major inhibitory neurotransmitters
neurons, gamma-aminobutyric acid , GABA, glycine
Tetanospasmin hydrolyzes the ______ proteins (?) required by _______-containing vesicles to fuse with the ___-______ membrane. Once the _____ proteins are hydrolyzed, the synapse ______, taking ____- ______ to regenerate
docking, VAMP aka synaptobrevin, neurotransmitter, pre-synaptic, docking, degenerates, weeks, months
Describe the pathogenesis of tetanus?
Once infected animal releases toxin, and the toxin affects the nerves
Neurotoxin travels inside axon to cell bodies into spinal chord
Tonic spasms in muscles
Animal suffers from spastic paralysis
C. Tetani and production of toxin tetanospasmin
Toxin binds to neurons and blocks the release of inhibitory vesicle
But on the other side, the neurons release the chemical mediators that stimulate the contraction.
Acetylcholine is producing constant contraction of the muscles.
It is a continuous?
Stain for spore = malakita green
Describe the disease patterns of Tetanus?
Early signs, following an incubation period of a few days
to several weeks are:
• Stiffness, muscular tremor, and increased responsiveness to
stimuli
• Mortality is at least 50% and highest in the young
animals
What are the signs and symptoms of tetanus in horses, ruminants, and swine?
• Signs include:
• Retraction of the third eyelid, erectness of ears, grinding of teeth and
stiffness of the tail
• Bloat is common in ruminants
• Feeding becomes impossible (Lockjaw)
• Rigidity of extremities cause “Sawhorses” attitudes and eventually
recumbence
- contraction of muscle in diaphragm and intercostals —> ?
• Fecal and urinary retention, sweating (esp. horses) and high fever
• Consciousness persists
• Death, due to respiratory arrests, occur in lambs and piglets within the
first week, in adult animals in 1-2 weeks
• Full recovery requires weeks to months
What can be seen here?
Extended neck, posture changed to help breathe better
Constant contraction of muscle of thoracic limbs
no gross lesions in brain or muscle; see nothing -> relying on clinical diagnosis only.
What can be seen here?
Rigid hind leg
What can be seen here?
The source of the tetanus infection,
with the other cat’s tooth
Injury is almost healed; this tooth was removed from this area.
What can be seen here?
Prolapse of third eye lid
Extended thoracic and pelvic limbs
Erect ears
What can be seen here?
Prolapse of third eye lid
Extended thoracic and pelvic limbs
Erect ears
Describe the immunologic aspect of Tetanus.
• Acquired resistance depends on circulating antitoxin
• Survivors are susceptible to re-infection
• Not enough toxin present to induce a strong immune-response
(neutralizing antibodies)
• Passive and active protection is provided by administration
of antitoxin or immunization with toxoid
Toxin is the main fighter of this disease.
Sometimes, the amount of the toxin is very low
Can vaccinate the horse as a preventative measure. After two or three weeks, when boost the horse, production of Ab is faster and more efficient.
Describe the laboratory diagnosis of tetanus.
• Gram-stain smear from suspected wound may reveal the
typical “drumstick” type bacteria
• Wound exudate is plated on Blood agar in anaerobic
culture
• Hemolytic due to tetanolysin
• Drop of antitoxin will inhibit hemolysis
• Injection of suspected isolates can be injected into two
mice (One received antitoxin)
• Molecular diagnosis (PCR) can be used to support
How do you treat a patient with tetanus?
• Therapy aims at:
• Neutralization of circulating toxin
• Injection of adequate dose of antitoxin
• 10,000-300,000 units for horses
• Suppression of toxin production
• Wound care and large doses of parenteral penicillin or metronidazole
• Flushing of hydrogen peroxide to create aerobic conditions
• Life support and symptomatic relief to the patient
• Use of sedatives and muscle relaxants and exclusion of external stimuli
• Artificial feeding by stomach tube or intravenously may by necessary
after the hyperesthetic phase
• Nursing care is most important
How do you prevent Tetanus?
• Wounds should be properly cleaned and dressed
• During surgical procedures appropriate hygienic precautions should be
observed
• Especially on mass scale under farm conditions
• Horses unless actively immunized, are given antitoxin after injury or surgery
and/or penicillin
• Active immunization employs formalinized toxoid given twice at 1-2 month
intervals and annually thereafter
• Passive immunity passes from immunized mares to nursing foals and appears to
provide protection for about 10 weeks, when toxoid can be given.
_______ ____ causes Botulism
Clostridium botulinum
Botulism is a ______ intoxication characterized by _____ _____.
Neuroparalytic, flaccid paralysis
• Intoxication caused by any of the seven protein neurotoxins
• A to G
• Type G has been renamed C. argentinense
• C and D are the most common in domesticated animals
• Identical in action but differ in potency, antigenic properties and
distribution
Botulism affects ?
mainly ruminants, horses, mink, and fowl
(waterfowl)
• Swine, carnivores and fish are rarely affected
Humans are susceptible as well
Type G = now know as C. arg…
Located in soil-contaminated food —> humans in Argentina
Meat, canned products,
Botulinum neurotoxins (BoNT) acts in the
neuromuscular junction
Zinc endopeptidases with identical activity that binds to _______ ____ cells
• Decreases the release of ______
Once hydrolyzed, the ______ degenerates, taking weeks to months to regenerate
cholinergic, nerve, acetylcholine, synapse
BoNT are secreted with ______ proteins
• Aid in the survival in the ___ tract
accessory, GI
When toxin in ingested, it is a protective toxin b/c of its accessory proteins, which is why it i snot degraded by digestive enzymes
What is a reservoir for Botulism?
• Soil and aquatic sediments
• Vehicles of intoxication are contaminated animal and plant material
• When animals die, the spores (common in gut and tissues) germinate
and generate toxin, which may be ingested by carrion eaters or
contaminated environment
• Contaminated cans of meat and vegetables
How is Botulism transmitted?
• Toxin ingestion (toxin is more important than the number of bacteria)
• Spore ingestion (Important in human infants botulism)
• Wound contamination (rarely in humans and horses)
Describe the pathogenesis of Botulism
Muscles of respiration are not contracted here; they just expand.
When breathe, muscles expand but do not contract
What are the clinical signs of Botulism?
• Muscular incoordination leading to:
• Recumbency
• Extrusion of the tongue (b/c tongue is paralyzed)
• Disturbances in chewing and swallowing food
What happens to a patient’s consciousness in cases of Botulism?
No changes in consciousness occur
How is patient temperature affected if they have Botulism?
Temperature remains normal
• Unless secondary infections occur (Pneumonia)
Describe the recovery process in nonfatal cases of botulism.
In nonfatal cases, recovery is slow and residual signs may
persist for months
If you go to farm, and see this animal can either be tetanus or botulism. But if you see more than one = botulism
Multiple rather than just one animal = botulism
Birds die and the bacteria starts growing and producing toxin in cadaver.
Cadaver contaminates water and food.
Neck paralysis
Hen with botulism
• Limberneck
• Initial clinical sign of botulism
Describe laboratory diagnostic process for botulism
• Requires demonstration of the toxin in plasma or tissue
before death or from a fresh carcass.
• Isolation of the organism is not definitive.
• Demonstration of toxin in feedstuffs, fresh stomach
contents, or vomit.
What are the steps of lab diagnosis of Botulism
• Toxin is extracted from material and injected into guinea
pigs or mice
• Still the only accepted method of confirmation
• Death occur within 10 h – 3 weeks (average 4days)
• Death is preceded by muscular weakness, limb paralysis, and
respiratory difficulties
• Any toxin must be neutralized by one of the C. botulinum
antitoxins
Make sure to take a sample from food and water as well
How can you isolate botulism from a sample
?
• Isolation is possible
• Heat samples 65-80°C for 30 min to induce germination and
culture anaerobically on Blood Agar
How can you support a Botulism diagnosis?
• Serological and molecular techniques are available to
support the diagnosis
Egg yolk agar showing the lipase
reaction after 72 hours of incubation
Colony grown on a 72 hour blood agar
plate
What would you do in a case of recent ingestion in botulism?
Recent ingestion
• Evacuation of the stomach and purging is helpful
How would you treat a patient with botulism?
Antitoxin treatment following onset of signs is
sometimes beneficial
• Mainly in minks and ducks
Might have to vaccinate more often if disease is more common
Animals at risk of contracting Botulism should?
be vaccinated with toxoids (A-D)
What are some other forms of treatment and control for Botulism?
• Polyvalent antiserum
• Removal of affected waterfowl to dry land saves many birds
from exposure and drowning
• Placing feed on dry ground attracts birds from contaminated
areas
• Guanidine and tetraethylamide stimulates acetylcholine
release
• Vaccination (Toxoid) in endemic areas
