Staphylococci Flashcards
Cocci bacteria
staph, strep, enterococcus
bacilli: Spore forming
- Bacillus (facultative anaerobe)
- Clostridium (obligate anaerobe)
Bacilli: Non-spore forming
- Listeria
- Corynebacteria
Strep
catalase negative
Staph
catalase positive
What kind of infection are Staph and Strep common in?
- skin infections/eruptions
- wound infections
- upper respiratory infections (sinusitis/pharyngitis)
- Pneumonia
- food poisoning/TSS
- septicemia/disseminated infections
staph/strep accounts from the majority for what kind if infections?
suppurative infections
- also abscess formation-> can only spread along tissue planes
- role of phagocytosis/opsonization very important
diseases that interfere with ________ function result in pyogenic infections?
neutrophils
- diabetes
- chronic granulomatous disease
is staph a native flora?
Yes
-ubiquitous (common cause of skin abscesses)
Coagulase positive staph?
Staph. aureus
coagulase negative staph?
Staph. epidermidis
- infects damaged tissue
- contamination of devices, implants-> lead to infection
what are general forms of disease from staph?
- local infections/abscess formation
- bacteremia (sepsis)-> can be to heart valves, kidneys, bones, joints
- toxin-mediated diseases: food poisoning, TSS
what are the virulence factors of Staph?
- coagulase +/-
- cytolytic toxins
- lipases
- penicillinase, plasmid mediated antibiotic resistance
- fibronectin and vitronectin-> bind to host cells
- protein A: binds Fc portion of immunoglobulins
what are toxins from staph?
- enterotoxins
- cytolytic toxins
- exfoliative toxins
- toxic shock syndrome toxin (TSST-1)
Pathogenic factors in S. aureus
- Suppurative disease: impetigo, folliculitis
- Enteritis
- TSS
- Postoperative pneumonia
- staphylococcal scalded skin syndrome
- food poisoning
For staph infections: over growth of NF/UPT leads to?
sinusitis
otitis media
For staph infections: access to sterile areas leads to?
- skin, wound infection
- hematogenous spread from punctures
- bacteremia spread to joints, bone, heart valves. etc
For staph infections: deep infections in immunosuppressed/debilitated leads to?
necrotizing pneumonia, septicemia
types of skin/wound infections?
furuncle, carbuncle, sutures/foreign bodies, impetigo
staph infections are a common cause of ________ infections?
burns, surgical, nosocomial infections
staph infections of UPT are usually caused from?
obstruction with overgrowth of colonizing bacteria
-sinusitis, otitis media, pharyngitis
what are UPT is usually associated with?
- secondary to viral infection
- diabetes
- trauma or irritation
- foreign bodies
- duct obstruction
what are the two toxic mediated diseases with staph?
food poisoning
TSS
what toxin causes food poisoning with staph?
enterotoxin
- short incubation (1-6 hours)
- custards, milk, meats, potato salad
