2026 QUESTIONS AND ANSWERS GRADED
A+
what bacteria causes majority of bone infections
staph aureus
Nonhematogenous osteomyelitis
direct inoculation (bone fracture/joint replacement), spread from surrounding soft
tissue
hematogenous osteomyelitis
infection that seeds the bone in the setting of bacteremia
s/sx of osteomyelitis
pain, localized tenderness, warm/erythema, fever, bone pain
possible etiology/complications of staph bacteremia (3)
,endocarditis, osteomyelitis, implantable device/hardware from surgery
toxic shock syndrome toxin
life threatening complication that results from toxins super t-cell antigens causing a
MASSIVE T-cell activation (lots of cytokines)
super T cell antigen
produced by staph aureus that induces T-cells and cause release of IL1, IL2, and
TNF in super large quantities
MC cause of TSS
staph aureus -- tampons!!!
GAS
what is staph epidermidis and what is it associated with
,part of normal skin flora -- usually hopsitally acquired and infects prosthetic
devices and indwelling catheters (PICC) creating BIOFILMS
staphylococcus saprophyticus disease association
second-MC cause of community-acquired UTI (WOMEN)
honeymoon cystitis -- within 24 hours of sex
Gram positive vs Gram negative cell walls
Gram pos. = thick layer of peptidoglycan
Gram neg. = thin layer of peptidoglycan
**negative have outer cell membrane**
Lancefield grouping
classification system for streptococci
, designated by letters
Main 3 shapes for gram positive
bacilli, cocci, branching filaments
staph aureus shape
grape-like cluster of cocci
main types of staph aureus infections (3)
skin infections, impetigo, abscesses
TSS, food poisoning, osteomyelitis
definitive tx of staph aureus (sx and abx)
surgical: I&D
abx: