Gram + Bugs Flashcards
What are the gram + bugs?
- staphylococcus
- streptococcus
- clostridium botulinum
- corynebacterium Diptheriae
- closstridium tetanus
- bacillus antracis
On microscopic examination what shapes are staph ans strep?
- staph: cocci, clusters (grape shaped)
- strep: diplococci, chains
Positive Gram stain is what color? Negative?
- positive is purple
- negative is red
What are these shapes?
- bacillus
- cocci
- spirillum
- rods
- sphere
- spiral
What are all of the staphylococcus species?
- staph aureus
- staph epidermidis
- staph saprophyticus
What are all of the streptococci species?
- strep pyogenes (Group A)
- strep agalactiae (Group B)
- strep pneumoniae
- strep viridans
- enterococcus (Group D)
What is the difference between localized and generalized infections?
-generalized infections spread through the lymphatics, tissues, blood stream, and possible other routes.
Common Bacterial Infections
- Localized
- Lethal
- local: cellulitis, erysipelas
- lethal: nectrotizing fasciitis (flesh eating),
myconecrosis (gas gangrene or clostridial myonecrosis),
pyomyositis (abscess from bacterial infection of skeletal muscle)
What is the coagulase test? How does it aid in differentiating gram + staph sp.?
- coagulase: converts H202 to O2 and H20, makes bubbles.
- aids in differentiation because staph aureus is the only coagulase + bacteria. When H202 added to agar it bubbles.
What are some of the different infections that staph induces throughout the body?
stye
boils/carbuncles
sinusitis
hematogenous spread (IV drug use, epidermidis is common staph)
impetigo (weepy, mass on the skin, honey color crust)
diarrhea (staph enterotoxins)
toxic shock syndrome*
scalded skin syndrome*
Food poisioning*
osteomyelitis
pneumonia
endocarditis
What are the common skin and soft tissue infections in the immunocompetent host? Others?
- abcesses
- folliculitis
- Mastitis (infection of the breast)
- wound infections
- infected IV catheter sites
Others:
- bacteremia/septicemia/endocarditis
- pneumonia
- muscoloskeletal: septic arthritis
What is HA-MRSA & CA-MRSA? What is each associated with? How is CA-MRSA spread?
- HA-MRSA: Healthcare associated MRSA, associated w/ invasive procedures or devices. Healthcare workers as well.
- CA-MRSA: community acquired MRSA of healthy ppl. Can begin as painful boil but suddenly explodes within 24hrs.
Spread skin to skin contact, high risk individuals are wrestlers, child care workers and people who live in crowded conditions.
What might MRSA resemble? How does it develop?
-resembles spider bite*, boil, or pimple. May quickly develop into deep painful abcesses requiring surgical draining. Sometimes go deeper into the tissue causing life-threatening infections in bones, joints, blood stream, heart valves, and lungs.
What meds do we use to treat MRSA? What are some of the alternative tx?
- Sulfa
- Doxycycline
- Vancomycin
- alternatives:
- bactroaban ointment in nose qd
-full body wash (rules of 3) (Hibiclens) 3x/day for 3day then 3x/week for 3weeks.
What are some of the clinical features of cellulitis?
-red, swollen, shiney, warm, NO pus, tender
What are the differences between Group A streptococci and staphylococcus aureus?
- Group A strep typically follows an unrecognized injury inflammation is diffuse, spreading along tissue planes. No area of pus.
- Staphylococcus aureus usually associated with wound or penetrating trauma, localized abcess becomes surrounded by cellulitis.
What syndromes occur in the following layers?
- epiderimis
- dermis
- superficial fascia
- subcutaneous tissue (subQ fat, nerves, arteries, veins, deep fascia)
- muscle
E: erysipelas, impetigo, folliculitis, furunculs, carbuncules
D & Superficial: cellulitis
SubQ: necrotizing fascitis
M: myonecrosis
Tx of Cellulitis
- Bactrim (DOC)
- Clindamycin (for sulfa allergy)
- Vancomycin
*if fever, admit to hospital and administer IV abx.
Can cephalosporins be used in the tx of cellulitis?
-NO!!! they are resistant!
What is an abcess? What is the most common bacteria in an abscess?
- when the tissue area of cellulitis turns into pus under the surface of the skin.
- staph aureus
Whats the difference between abscess and empyema?
-empyemas are accumulations of pus in a preexisting rather than a newly formed anatomical cavity
What are some examples of deep seated infections?
hepatic abscess, splenic abscess, sub-phrenic abscess, rectal abscess
Clinical features of an abscess?
- cellulitis present?
- swollen
- soft center, fluid underneath
- painful
Tx of abscess?
- I&D
- Abx
*abx cannot penetrate site w/o being drained