Causative organism in acute bacterial endocarditis is -
Acute osteomyelitis may be : -

i. Primary (hematogenous):- Organisms reach the bone through the bloodstream.
ii. Secondary:- Organism gain energy directly through wound such as in compound fractures or surgical operation,

Hematogenous osteomyelitis is the commonest form of osteomyelitis and most common source of bone and joint infection is hematogenous.
it is caused most commonly by Staphylococcus aureus.
Other causative organisms are streptococcus, pneumococcus, and gram-negative bacilli.
Staphylococcus aureus
Streptococcus viridans
Pneumococcus
Streptococcus pyogenes