Staphylococcus

Where are Staphylococci usually found?

On the skin and mucus membranes. - Upper respiratory tract - Digestive tract

What common clinical condition do dogs get as a result of a Staph. pseudintermedius infection?

Otitis externa

Does beta haemolysis in Staphylococcus sp. cause full lysis of RBCs or partial?

Partial

What age of pig is usually affected with exudative epidermitis?

Piglets from 1-12 weeks of age

Define pyaemia

Pyaemia is a term used to describe blood poisoning caused by the spread in the bloodstream of pus forming bacteria released from abcesses.

Microscopically what colour are the colonies of the human strain of Staphylococci?

Yellow/Golden colonies

Microscopically what colour are the colonies of the dog strain of Staphylococcus?

White

What is the chronic phase of tick pyaemia associated with?

Bacterial deposition in vital organs and joints

Does alpha haemolysis in Staphylococcus sp. cause full lysis of RBC or partial?

Complete lysis of RBC

What clinical conditions in turkeys occur as a result of Staph. aureus infection?

- Arthritis - Septicaemia - Bubble foot

What are Staphylococci sensitive to?

- Common disinfectants - Aliline dyes

Describe the morphology of Staphylococci

- Form together in irregular clusters and irregular planes of division

Describe Staphylococcus aures on agar.

- Golden/yellow colonies. - Has both alpha and beta haemolytic properties

Name the other clinical conditions that dogs get as a result of infection with Staph. pseudintermedius

- Occular infections - UTIs - Mastitis - Pyometra - Joint infections

What are Staphylococci resistant to?

- Phenolic compounds - 20% NaCl solution - Crying out - Being heated to 60 degrees for 30mins

What is the acute phase of tick pyaemia associated with?

- Staph. aureus infects tick bite wound - Colonies localise in the joints - Abscess formation and septicaemia

What other clinical conditions do sheep have as a result of Staph. aureus?

- Tick pyaemia - Benign folliculitis - Dermatitis

Describe Staphylococcus hyicus on agar

- White colonies - Non-haemolytic

Describe Staphylococcus pseudointermedius on agar.

- White colonies - Partial beta-haemolysis

Tick pyaemia affects lambs of which age?

2-10 weeks old (after exposure to tick infested pasture)

Which type of haemolysin damages the blood vessels of the udder leading to necrosis and gangrene?

Alpha-haemolysin

What clinical condition of cattle is associated with Staph. pseudintermedius?

Bovine mastitis

What term describes acute - mild cases of pyogranulomatous lesions of the joints?

Bumble foot

What surgical procedure in colts is most commonly associated with Botryomycosis?

Castration

Are Staphylococci catalase positive or negative?

Catalase positive

What is the usual habitat of Staph. hyicus in cattle, pigs and poultry retrospectively?

Cattle: Found in the udder and in milk Pigs: Skin Poultry: Skin and nares

What is the most common cause of Botryomycosis?

Chronic infection of accidental/surgical wounds

What are the effects of Staphylococcus aureus alpha-haemolysin on the plasma membrane porin?

Cytocidal effects on the cell

What is the usual habitat of Staph. pseudintermedius?

Dog and cat nasopharynx

What is greasy pig caused by?

Epidermolytic toxin

Are staphylococcus gram positive or gram negative?

Gram positive (stains purple due to peptidyglycan)

What condition affecting pigs is Staph. hyicus associated with?

Greasy pig (exudative epidermitis)

What is special about beta-haemolysin?

It is unique to animal strains

Define botryomycosis

It's also known as bacterial pseudomycosis is a rare chronic granulomatous bacterial infection that affects the skin, and sometimes the viscera.

What clinical condition does Staph. aureus cause in cattle and sheep?

Mastitis

What are the effects of Staphylococcus aureus alpha-haemolysin on the smooth muscle in blood vessel walls?

Necrosis and constiction

What occurs is pyogranulomatous lesions of the joints of poultry become acute - severe?

Septicaemia and arthritis

Pyogranulomatous lesions in the joints of poultry is usually a result of which bacteria?

Staph. aureus

Tick bites result in which bacteria entering the wound to promote localisation of bacterial colonies?

Staph. aureus

Which bacteria is the most common cause of mastitis in sheep?

Staph. aureus

What do you witness during the catalase test for Staphylococci?

When you add hydrogen peroxide to the bacteria you will see bubbles of oxygen released

What form of mastitis infection as a result of Staph. aureus is most economically significant to the farmer? Why?

The Chronic Phase - Sub-clinical form of the disease and results in a reduced milk yield and a high somatic cell count

What is the result of the acute phase of Staph. aureus mastitis infection?

The animal will develop a high fever due to toxaemia and will die.

Where are micrococci usually found?

The mammary gland (they are usually non pathogenic)

If the agar is heated then cooled, what will happen to partially haemolysed RBCs?

They will be completely destroyed.

What is the catalase test used for?

To distinguish between Staphylococci (catalase positive) and Streptococci (catalase negetive).