Bugs - Strep, Enterococci Flashcards
what are viridan streptococci?
alpha(partial) and gamma(none) hemolyzers
1 bacterial cause of pharyngitis?
streptococcus pyogenes (group a strep)
fever, absence of cough, purulent exudate, cervical lymphadenopathy
microbiological/lab characteristics of pneumococci
GP catalase negative alpha-hemolysis susceptible to optochin soluble in bile salts
common presentations of streptococci pneumoniae
otitis, sinusitis, bronchitis, pneumonia, meningitis, bacteremia
most common bacterial cause of otitis, meningitis
treatment for a pneumococcal meningitis
ceftriaxone and vancomycin
….macrolide if atypical
treatment for a pneumococcal otitis
amoxicillin if fever is persistant dont need to treat right away
most common species of enterococci how do their treatments differ?
E. faecalis - ampicillin/penicillin are drugs of choice; use ampicillin AND aminoglycoside for endocarditis
E. faecium - vancomycin is drug of choice; resistant to ampicillin; use vancomycin AND aminoglycoside for endocarditis
types of patients commonly getting enterococcal UTI
males hospitalized, catheterized pts not common in healthy, non-hospitalized females
osler node vs janeway lesion what are these?
osler node is PAINFUL; erythematous nodule on thumb pad
janeway lesion is not paintful; erythematous nodule on hypothenar emminence
where do enterococci colonize?
most important virulence factor?
GI tract!
antibiotic resistance is most common virulence factor…comes from antibiotic use affecting microbiome…
prevnar
pneumovax
both pneumococcal vaccines
prevnar - given to all children
pneumovax - 65+ y/o
most common Group A strep species?
most common Group B strep species?
what determines grouping?
group A - s. pyogenes
group B - s. agalactiae
groups are determined by its common cell wall carbohydrate
M protein
virulence factor for s. pyogenes
adhesive - binds many serum proteins including factor H and CD46 on keratinocytes
forms antibodies that react w/cardiac myosin and sarcolemma
strongly antiphagocytic
streptolysin O, streptolysin S
hemolysins produced by s. pyogenes
pyrogenic exotoxins produced by s. pyogenes
SpeA, SpeC - superantigens; responsible for scarlet fever and toxic shock syndrome; HLA dependent; encoded by bacteriophages
SpeB - cleaves IgG
suppurative vs non-suppurative infections of s.pyogenes
suppurative(pus producing):
- pharyngitis(can be complicated by scarlet fever)
- impetigo, erysipelas, necrotizing fasciitis, strep. TSS
non-suppurative:
- rheumatic fever, rheumatic heart disease
- glomerulonephritis
treatment options for this?
pharyngitis; GAS(s. pyogenes)
penicillin
if allergic: macrolides, clindamycin
scarlet fever
manifestation?
uncommon manifestation of acute infection, usually pharyngitis
manifests from SpeA, SpeC release
rash starts at trunk
capillary fragility
strawberry tongue and peripheral desquamation in later stages
what streptococcal subgroup is s. pneumoniae a part of?
the mitis subgroup
what are the major/minor criteria for rheumatic fever?
major:
- polyarthritis
- carditis
- chorea
- erythema marginatum
- subcutaneous nodules
minor:
- arthralgia
- fever
- elevated CRP or ESR
- 1st degree heart block
need 2 major or 1 major and 2 minor to declare
what MUST you do if you see a pt with streptococcus **bovis **
this is Group __ strep
colonoscopy
s. bovis group(including s.gallolyticus) is a Group D strep that is highly associated with colon cancer
treatment for group b strep
penicillin
vancomycin or clindamycin if allergic
neonate gets fever in first 4-6 weeks of life
doc orders an LP
what is the doc looking for?
group B strep: s. agalactiae
normally colonizes GI/GU(can be picked up in birthing canal)
sepsis and meningitis are risks for both early and late onset!
what infeciton precedes acute rheumatic fever
what is the incubation period
10-30 days following a pharyngitis from a GA-strep infection
treatment for s. agalactiae infection?
penicillin
if allergic: vancomycin or clindamycin
screen pregnant women and treat those that are colonized when at term
what is the s. milleri group?
what disease manifestation are they associated with?
unofficial name for virdans group of bacterial:
(s. anginosis, s. constellatus, s. intermedius)
can display beta, alpha or gamma hemolysis
unusual propensity to cause abcess - liver, brain, periodontal
angie intermediately looks at constellations
