Bacillus Spp. / Neurogenic Clostridium Spp Flashcards
What are the types of bacillus that we are studying?
Bacillus
Bacillus anthracis
Bacillus cereus
Bacillus thuringiensis
How are bacillus normally present when seen on slides?
Rods, in pairs or long chains
Bacillus is widely distributed in the environment
Endospores can survive more than 50 years
Resist desiccation, high temperatures, and chemical disinfectants
Is bacillus oxidase positive or negative? is it catalase positive or negative? Is it motile? Are most pathogenic? Do they produce endospores? What kind of media can they grow on?
What does it mean if a bacteria is oxidase positive?
Oxidase positive bacteria possess cytochrome oxidase or indophenol oxidase (an iron containing haemoprotein). Both of these catalyze the transport of electrons from donor compounds (NADH) to electron acceptors (usually oxygen). The test reagent, N, N, N’, N’-tetramethyl-p-phenylenediamine dihydrochloride acts as an artificial electron acceptor for the enzyme oxidase. The oxidized reagent forms the coloured compound indophenol blue.
What are some features of B. anthracis, and B. cereus?
What are features of bacillus antracis?
Colonies up to 5 mm in diameter, flat, dry, greyish appearance (medusa head at edge of the colony) No hemolysis
What bacillus bacteria is seen in this image?
Bacillus anthracis
What bacillus bacteria is seen in this image?
Bacillus anthracis
What bacillus bacteria is seen in this image?
Bacillus anthracis
What bacillus bacteria is seen in this image?
Bacillus cereus
What bacillus bacteria is seen in this image?
Bacillus cereus
What are features of bacillus lincheniform?
Bacillus licheniform: Colonies are dull, rough, wrinkled and strongly adherent to the agar
What bacillus is seen in this image??
Bacillus licheniform
What are features of bacillus cereus?
Bacillus cereus: Colonies similar to B. anthracis but larger with a greenish tinge Hemolysis around the colony
What is the clinical manifestation of B. anthracis in cattle, sheep?
Fatal peracute or acute septicaemic anthrax
What is the clinical manifestation of B. anthracis in pigs?
Subacute anthrax with oedematous swelling in pharyngeal region; an intestinal form with higher mortality is less common
What is the clinical manifestation of B. anthracis in horses?
- Subacute anthrax with localized oedema; septicaemia with colic and enteritis sometimes occurs
What is the clinical manifestation of B. anthracis in humans?
Skin , pulmonary and intestinal forms of anthrax are recorded in humans periodically.
What is the clinical manifestation of B. cereus in cattle?
Mastitis (rare)
What is the clinical manifestation of B. cereus in humans?
Food posioning/ eye infections
What is the clinical manifestation of B. licheniformis in cattle, sheep?
Sporadic abortion
What is the epidemiology of Bacillus?
Endospore -> alkaline soils, rich in Ca and N-> Contaminated pastures, buried carcasses-> Ingestion of spores, inhalation or through the skin
What is the pathogenesis of Bacillus?
Capsule provides resistance to phagocytosis
Toxins components: Protective antigen (binding moiety), oedema factor and lethal factor.
Neutrophils is the target of the oedema factor.
Macrophages, dendritic cells neutrophils and some epithelial and endothelial cells are
the target of the lethal factor
What are the clinical signs of Bacillus?
Clinical signs: Cattle and sheep are more susceptible, fever, depression, congested mucosae and petechiae, abort.
What are the lesions caused by Bacillus?
Lesions: rapid bloating, incomplete rigor mortis, ecchymotic hemorrhages and oedema, 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 are the characteristics of clostridiums?
• Characteristics
• Straight or slightly curved rods
• Produce endospores. The size, shape and location of the endospores can be
used for species differentiation. • More than 100 species but less than 20 are pathogenic.
Clostridial cultures typically emit ____ ____
putrid odors
In clostridium what is the most common mode of energy production?
Peptide catabolism is the most common mode of energy production by clostridiums
What are the key characteristics of clostridium?
What are saprophytes?
Clostridia are saprophytes, they constitute part of the normal intestinal flora and some may be sequestered as endospores in muscle or liver. Sequestered endospores, if activated, may produce disease.
What are the histotoxic clostridia?
What are the enteropathogenic and enterotoxaemia producing clostridia?
What is the atypical clostridia organism?
C. piliforme
What are the neurotoxic clostridia?