Staphylococcus 1 Flashcards
What are the major points to understand about Pathogenic Streptococcus spp?
tend to be species-adapted
With staphylococcus what test is used to determine if its Staphylococcus aureus or other type of Staph?
coagulase test - S. aureus is coagulase pos
Transmission of Staphylococcus spp. can occur how?
via exogenous or endogenous spread
What factors would predispose and animal to Staphylococcus?
Compromise in the integrity of skin or mucous membrane
Impairment in some other host defense
Presence of a foreign body - e.g. catheter, suture, prosthesis
What are the cell associated virulence factors of Staphylococcus?
capsule, protein A, adhesions
What is the purpose of protein A virulence factor?
avoid phagocytosis
Exotoxins are a virulence factor for Staphylococcus. What is their pathogenic effect?
Food poisoning in humans
What are the three Staphylococcus species of veterinary importance?
S. auerus, S. pseudointermedius, S. hyicus
Of the three veterinary importance Staphylococcus which ones are coagulase positive?
S. aureus
S. pseudintermedius
Clinical conditions due to S. aureus in sheep are:
Tick pyemia, mastitis, dermatitis
S. aureus causes what in horses?
Scirrhous cord - botryomycosis of the spermatic cord
S. pseudintermedius in dogs causes what?
Pyoderma, endometritis, cystitis, otitis externa and other suppurative conditions
If we are culturing Staphylococcus what would we see on blood agar?
Observe for colony morphology
Hemolysis
What biochemical tests are used for diagnosing staphylococcus spp?
Catalase
Coagulase
DNase
Latex agglutination tests
T or F Staphylococcus spp. are non-fastidious.
True - grow on non-enriched media
What do staphylococcus colonies look like on medium?
yellowish/golden (especially S. aureus)
What type of test would you utilize to distinguish between S. aureus and S. epidermidis?
Tube coagulase test
Methicillin-resistance (MR) is the major cause of antibiotic resistance with Staphylococcus. What encodes for this resistance? Which antibiotic is it resistant against?
mec A/C gene, resistance to beta-lactam antibiotics
Due to multidrug resistance staphylococcal infections in animals, what antibiotics are veterinarians left with for treatment?
rifampicin, chloramphenicol, aminoglycosides, newer antimicrobial agents
What are the three major points to understand about Staphylococcus spp?
major opportunistic pathogen, associated pyogenic infections, mainly involved in skin and soft tissue infections
T or F Some Enterococci are of emerging importance because of innate resistance to most common antimicrobials
TRUE
What test do we use to determine if its staphylococcus or streptococcus?
staph is catalase positive, step and enterococcus are catalase negative
Staphylococcus are Gram () that form clusters
Gram (+)
irregular clusters that resemble a bunch of grapes
Staphylococcus spp. are resistant to what enzyme?
lysozyme
What type of infection to Staphylococcus spp. cause?
pyogenic infections (via opportunistic pathogens)