Unit 5 - Endospore Forming Gram positive Rods (Cram)

How long can endospores last in the environment?

50+ years

True or false: The spore is a dormant form and does not reproduce

True

What are the two main families of gram positive spore forming rods?

1. Bacillus

2. Clostridium

What is the bacterial morphology of Bacillus species?

Rectangular shaped bacilli in chains, like "boxcars", have a central spore

What are three defining characteristic of Bacillus species?

1. Capsulated

2. Most species are non–pathogenic

3. Catalase positive

What are the cultural characteristics of Bacillus species?

Medusa head colonies (lots of bulges on surface of colony), gamma or beta hemolysis

What Bacillus species can cause food poisoning in humans and mastitis in cattle?

Bacillus cereus

What Bacillus species causes anthrax?

Bacillus anthracis

Why should a carcass of an animal who showed clinical signs of anthrax not be autopsied?

Sporulation of Bacillus anthracis is triggered when vegetative cells are exposed to air

Which group of animals are the most susceptible to anthrax?

Ruminants (cattle, sheep, goats)

Which group of animals are the most resistant to anthrax?

Birds

What are the three ways Bacillus anthracis spores can enter a host?

1. Ingestion during grazing

2. Infection by wound

3. Inhalation (rare)

Once Bacillus anthracis spores have entered a host and germinated into bacterial form, they release a toxin. What three effects does this toxin have on the body?

1. Leukocidal

2. Increases vascular permeability (brings blood to places it shouldn't be)

3. Produces capillary thrombosis (clots)

What is the most notable clinical sign associated with an acute Bacillus anthracis infection?

Bloody discharge from the mouth, anus, and body orifices

What clinical sign is common in horses with a subacute Bacillus anthracis infection?

Colic

What clinical sign is common is carnivores with a subacute Bacillus anthracis infection?

Gastroenteritis

How should the suspicion of a Bacillus anthracis infection be confirmed post mortem?

Blood smear to examine for presence of central spores

After staining with malachite green and safranin, how will spores appear?

Endospores are green

Vegetative cells are red

What does the layperson's term "Blackberry Jam" spleen actually refer to?

Splenomegaly

What are the two acceptable way to dispose of a carcass infected with Bacillus anthracis?

1. Deep burial

2. Incineration

What are the two treatments for anthrax?

1. Annual vaccination in endemic areas

2. Systemic antibiotics

What are the three routes of Bacillus anthracis infection in humans?

1. Cutaneous (common)

2. Inhalation

3. Gastrointestinal (rare)

What route of infection causes "Wool Sorters" disease in humans?

Inhalation

What are the three characteristics of Clostridia speceis?

1. Catalase Negative

2. Anaerobic

3. Non–capsulation

What is the bacterial morphology of Clostridia species?

Large bacilli in singles, pairs, or chains

What are the cultural characteristics of Clostridium species?

Irregular round colonies, hemolysis varies

Where are Clostridium species found in the environment?

Soil, fresh water, or marine sediment

Where in the body do Clostridium species germinate?

Damaged ischemic (diminished blood supply) muscle

What are the two significant neurotoxic Clostridia in veterinary medicine?

1. C. botulinum

2. C. tetani

What are the six significant histotoxic Clostridia in veterinary medicine?

1. C. chauvoei

2. C. haemolyticum

3. C. novyi

4. C. perfringens (A–E)

5. C. septicum

6. C. sordellii

What bacteria causes Blackleg?

Clostridium chauvoei

What age group of bovines does blackleg usually occur in?

Calves 6–24 months old

What is the medical term for the black colour of muscles effected with blackleg?

Terminal toxemia

What is the medical term for the swelling that occurs under the skin of muscles effected with blackleg?

Crepitant swelling

When are calves vaccinated against blackleg?

Twice, 2 weeks apart at 2–6 months of age

What bacteria causes malignant edema?

Clostridium septicum

Which bacteria does Clostridium septicum often cooccur with and/or get confused with?

Clostridium chauvoei

What is a Clostridium septicum infection called when it effects sheep?

Braxy

What bacteria causes big head?

Clostridium novyi (Type A)

What behaviour causes a Clostridium novyi (Type A) infection in rams?

Head bunting

What condition does Clostridium perfringens (Type A) cause in poultry/dogs, horses, and pigs?

Poultry/dogs – necrotic enteritis

Horses – colitis

Pigs – diarrhea

What condition does Clostridium perfringens (Type B) cause?

Lamb dysentery

What condition does Clostridium perfringens (Type C) cause in cattle and pigs?

Calves (up to 1 month old) – Enterotoxaemia

Pigs – Hemorrhagic diarrhea

What is a Clostridium perfringens (Type C) infection called in sheep?

Struck

What condition does Clostridium perfringens (Type D) cause?

Pulpy kidney disease/overeating disease in sheep

Why is a Clostridium perfringens (Type D) infection also known as overeating disease?

Excessive feed or milk, and high grain diets produce a suitably starchy environment for the bacteria

What condition does Clostridium novyi (Type B) cause?

Black disease/infectious necrotic hepatitis

What condition does Clostridium sordellii cause in cattle, sheep, and horses?

Myositis, liver disease, edema of SQ tissues, hemorrhage

What condition does Clostridium haemolyticum/novyi (Type D) cause?

Red water disease/bacillary hemoglobinuria

What test can be used to identify Clostridia?

Fluorescent antibody test (FAT test)

Why do Clostridium fluoresce on a FAT test?

Antibodies are labeled with fluorescein

What condition does Clostridium tetani cause?

Tetanus

What clinical signs does a horse have when infected with Clostridium tetani?

Erect ears, tail held stiffly, and "sawhorse" stance

What condition does Clostridium botulinum cause?

Botulism

What do the terminal spores of the Clostridium tetani make the bacteria look like?

Tennis racket/sour key

How does the muscular paralysis in an animal with botulism differ from an animal with tetanus?

Tetanus cases have rigid muscles, botulism cases have progressive flaccid muscular paralysis

What name is given to a Clostridium botulinum infection in a foal?

Shaker foal syndrome