Lesson 2a: Staphylococcus species

Question 1

Staphylococcus species

Answer 1

• Gram-positive cocci resembling grapes
• Grow on non-enriched media
• Facultative anaerobes, oxidase-negative, and catalase-positive
• non-motile and non-spore forming
• commensals on skin and mucous membranes
• causing pyogenic infections
• colonies of S. aureus and S. pseudintermedius produce double harmolysis

Question 2

Haemolysis in sheep or ox blood agar: Four staphylococcal haemolysis are recognized;

Answer 2

alpha, beta, gamma, and delta

Question 3

pyogenic characteristics causes what?

Answer 3

suppurative lesions

Question 4

staphylococcal cell wall proteins, which bind ___________ and ___________, facilitate bacterial attachment to tissues.

Answer 4

fibronectin and fibrinogen

Question 5

Exoenzyme that promote tissue invasion, and Exotoxin lyse host cell membrane

Answer 5

Exoenzyme: kinases and hyaluronidase
Exotoxins: haemolysins and leukocidin

Question 6

Demonstration of bacteria staphylococcus species

Answer 6

gram-staining, or culture on blood agar, selective blood agar, MacConkey agar

Question 7

staphylococcal diseases of importance in domestic animals include?

Answer 7

mastitis, tick pyaemia, exudative epidermitis, botryomycosis, and pyoderma

Question 8

S. aureus, most often causes subclinical infections

Answer 8

Bovine staphylococcal mastitis

Question 9

virulence factor of bovine staphylococcal mastitis that result to tissue necrosis and can be life threatening

Answer 9

Alpha toxin

Question 10

Lambs can carry S. aureus on their skin and nasal mucosa and infection occurs through minor skin trauma including tick bites.

Answer 10

tick pyaemia

Question 11

is a vector for the rickettsial agent of tick-borne fever

Answer 11

Ixodes ricinus

Question 12

which can cause immunosuppression in lambs and may predispose to staphylococcal infection, and characterized either by septicaemia and rapid death or by localized abscess formation

Answer 12

Anaplasma phagocytophilum

Question 13

S. hyicus; occurs worldwide in sucklers and weaned pigs up to 3 months of age.

Answer 13

Exudative epidermitis (greasy pig disease)

Question 14

can be isolated from the vaginal mucosa and skin of healthy sows

Answer 14

Staphylococcus hyicus

Question 15

produced by S. hyicus appears to be the major virulence factor as injection of this toxin into the skin of young pigs produces exfoliation

Answer 15

Exfoliative toxin

Question 16

S. aureus in horses; a chronic, suppurative granulomatous condition, which usually occur within a few weeks of castration in the horse due to infection of the stump of the spermatic cord (scirrhous cord); can also occur in mammary tissue of sows

Answer 16

Botryomycosis

Question 17

common cause of nosocomial infection in vet hospitals. most commonly reported. METHICILLIN-RESISTANT STAPHYLOCOCCAL INFECTIONS IN ANIMALS

Answer 17

• dogs with wound infections
• surgical site infections
• pyoderma
• otitis
• urinary tract infections