(02/03/15) Staphylococcus spp. (Daniels) Flashcards
the entire genus of staphylococcus is gram ____, non-____, non-______ _____ and are predominantly _____ _____
- positive
- non-motile
- non-spore forming
- facultative anaerobes
what test is used to identify if an infection is staph?
catalase test
what test is used to identify what specific type of staph an infection is?
coagulase test
what type of staph causes the highest burden of disease in people?
S. Aureus
if a coagulase test is positive, then the staph is most commonly ______
S. aureus
what five conditions have S. Aureus as the causative agent?
- aspiration pneumonia
- UTI
- toxic shock syndrome
- scalded skin syndrome
- food poisoning
S aureus lives on and around ____, and 30-40% show prevalence in the ____ _____
- people
- nasal carriage
what are the two ways that S aureus can enter the body?
- skin damage (wounds, burns, bites)
- mucosal surface damage
what three things does the spread of S aureus in the body depend on?
- bacterial inoculum (more is worse)
- host immunocompetence
- location of infection
what 6 populations are at the highest risk for S aureus?
- young children/ elderly
- diabetics
- ppl on immunosuppressive therapy
- HIV+
- dialysis
- IV drug users
what three things help S aureus to colonize and invade a host?
- fibronectin binding proteins
- collagen binding proteins (CNA)
- clumping factors (bind fibrinogen)
when S aureus attacks, _____ induce inflammation and release _____ to try to kill bacteria, which in turn, attracts other _____ that can actually do damage to the tissue
- PMN’s (neutrophils)
- ROS (reactive oxygen species)
- cytokines
what are the 3 virulence factors of S. Aureus?
- polysaccharide capsule
- Protein A (blocks antibody function)
- pore-forming toxins (pop PMN’s)
what is the disease that is manifested by staphylococcal toxins that is when the toxins cause the layers of the epidermis to separate? (does this by separating the ______ proteins in the skin)
staphylcoccal scalded skin syndrome (SSSS)
-desmosomes
TSST-1 is caused by S aureus and is considered a _______ which causes an unregulated _______ response by activating high numbers of _____ and _____.
- superantigen
- inflammation
- CD4
- T-cells
causes toxic shock syndrome
TSST-1 (superantigen)
during staphylococcal FOOD POISONING, the bacteria is considered an ______ rather than an _____.
- intoxication (much more severe)(rapid onset)
- infection
during staphylococcal FOOD POISONING, if you cook the food the heat will kill the ____ but not the _____ they have formed
- bacteria
- toxin
what antimicrobial drugs are used against S aureus?
penicillin binding proteins (PBP’s)
what strand of staph S aureus is resistant to penicillin binding proteins?
methicillin resistant S Aureus (MRSA)
MRSA frequently carries the _____ ____ to other drug classes
resistance genes
makes the body resistant to many types of drugs
what antimicrobial drugs is most commonly used against MRSA? (since penicillin and most others do not work)
vancomycin
what are the three most common sites of MRSA infection?
- nose
- axilla
- groin
how long can people carry MRSA after it is diagnosed?
up to 4 years
regarding MRSA, less that ____% of the general population carry it, but up to ____ % of healthcare professionals do
- 1%
- 15%
what is the most effective method to prevent the spread of MRSA?
wash your hands
