Gram Positive Cocci staph Flashcards
What is metabolism of Staphylococcus?
Facultative anaerobic
What is the result of the catalase test in Staph?
Positive
exceptions= anaerobic species; S. sacharolyticus, S. aureus subsp. anaerobius
What type of pathogen is Staph?
Classic opportunistic pathogen
What is the natural habitat of Staph?
Skin and mucous membranes.
Is staphylococcus apart of the normal flora?
It can be.
What is coagulase?
Enzyme that converts fibrinogen- Fibrin
What are the coagulase positive Staph species?
S. aureus S. aureus susp anaerobius S. intermedius group (S. pseudintermedius, S. intermiedius, S. delphini) S. hyicus (swine) S. schleiferi subsp. coagulans S. schleiferi subsp. schleiferi
What are the Coagulase Negative Staph species?
S. Felis S. Epidermidis S. hemolyticus S. saprophyticus S. similans
What is the clinical significance of Staph?
Suppurative conditions
Superficial- Skin & soft tissue ( Pyoderma, folliculitis, furunculosis, wound infections).
Deep infections ( Abcess, cellulitis, mastitis, pyomyositis, Necrotizing faciitis and myositis)
Infections of other body systmes ( Empyema, osteomyelitis, arthritis, endocarditis, pneumonia, otitis, sinusitis, menigitis)
Invasive bacteremia
What are chronic persitent relapsing infections?
Pyogranulomatous (Pus- Neutrophils and Macrophages).
For staph is there a “one host one pathogen” concept?
NO
Which speciases can be infected with staph?
all
Can one host species be predominantly susceptible to a species of staph?
yes
What virulence factors are associated with staph?
Many including
Adhesins,
enzymes,
Toxins
What is the understanding of the pathogenesis of staph?
No deep understanding
The interaction of Multiple virulence factors in a staph infection are critical? T/F?
True
What is TSST-1
Staphylococcal Toxic Shock Syndrome
What is Staphylococcal enterotoxin?
Staphylococcal food poisoning
Exfoliative toxins are associated with?
Staphylococcal scaled skin syndrome
The superantigen associated with staph is important why?
The superantigen has indiscriminate binding to Many T cells releasing cytokines causing problems
Protein A Virulence Factor, what is it?
Binds to FC portion of IgG- preventing phagocytosis
This virulence factor lyses RBC and other body Cells
Hemolysins
This virulence factor destroys tissues
Proteases
What does hyaluronidase as a virulence factor cause?
Destruction of connective tissue
Lipases
break down fat
Alpha toxins are responsible for?
Membrane damaging toxins
This virulence factor plays a role in necrotizing Fasciitis and pneumonia in dongs
Leukocidin
Exfoliative toxins
Staph scalded skin syndrome
Biofilm formation
Virulence factor allowing for further bacterial infection to persist.
what is the most common Dz in dogs regarding Staph?
Bacterial Folliculitis and Furnculosis
What is the most common Isolate in dogs?
S. pseudintermedius
Is S. aureus a “go to” in dogs for bacterial Dz?
No S. pseudintermedius
How is a Staph infection diagnosed?
Direct examination of specimen
Gram + cocci in clusters
Evidence of inflammation with abundance of Neutrophils is highly suggestive
Culture
Is PCR a good choice for a skin infection?
No, Normal flora on skin can cause misdiagnosis.
CONTAMINATION
What is important regarding Staph in Cattle?
S. aureus- Sub-acute or acute mastitis
Per-acute mastitis (gangrenous mastitis)
what causes Ulcerative Pododermatitis? and which species?
S. aureus- Humans and Porcine
Cervical Lymphadenitis in sheep is caused by?
S. auerus subsp. anaerobius
Bumble foot? who? What?
Birds feet big nasty ulcer, S. aureus
Botryomycosis is what?
Chronic pyogranulomatous inflammation
Found in rodents, humans and horses
Most common isolate= S. aureus
SQ or deep tissue
What is the first line of treatment choice for Staph?
1st generation cephalosporins (cephalexin)
All staphylococcus isolates which are macrolide (erythromycin) resistant should be considered Clindamycin Resistant unless confirmed by what?
D- Test
Chloramphenicol can be used but frequently is not used, Why?
Human health concern of idiosyncratic causing aplastic anemia
Types of treatment include?
Local therapy
Intra-articular injections
Regional perfusions
topical application in superficial infections
Mupirocin and Fusidic Acid (decolonization)
Chlorhexidine acetate
alternative therapies
What type of resistance is associated with staph species?
MRSA, MRSP
What mediates resistance resulting in altered penicillin binding protein (PB2a)?
mecA gene
What type of resistance is common in staph species?
Beta-lactamase
How can one tell if the client got the dog sick or vic a versa?
Pulse field gel electrophoresis.
To control the infection it is important to do what?
Avoid contact
good hygiene
isolate known infections if possible
client education ( MUST TELL OLDER OR IMMUNOCOMPETENT CLIENTS TO SEE PHYSICIAN!!!)
Treatment of colonized pet is not a normal practice
