QuestionSBA
QuestionChoice
*Streptococcus viridans* is found in dental plaque and is a common cause of endocarditis in patients with poor dental hygiene. However, this patient is most likely to be colonised with *staph. epidermis* as he has had a prosthetic valve replacement a month ago.
10025193
d
*Streptococcus viridans*
QuestionChoice
The most common causative organism of infective endocarditis overall is *Staph. aureus*. However, this patient has had a prosthetic valve replacement a month ago and therefore is at risk of colonisation with *staph. epidermis*.
10025191
b
*Staphylococcus aureus*
QuestionChoice
This patient has the typical findings of infective endocarditis: fevers (most common), weight loss, and chest pain. You may also find night sweats, muscle pains and lethargy as well as typical nail signs like splinter haemorrhages. The first two months after prosthetic valve surgery would put a patient at risk of infective endocarditis with *staph. epidermis*. Therefore, the most likely causative organism in this case is *staph. epidermis*.
10025190
a
*Staphlococcus epidermis*
QuestionChoice
This is an uncommon cause of infective endocarditis and therefore is not the most likely causative organism of this patient’s infective endocarditis.
10025194
e
*Coxiella burnetii*
QuestionChoice
This organism is associated with colorectal cancer. The question gives us no indications the patient has colorectal cancer. Therefore, *strep. bovis* is not a likely cause of this patient's infective endocarditis.
10025192
c
*Streptococcus bovis*
Concept
Chapter
2693
3710
Infective Endocarditis
Topic
134
Cardiology
17436
A 55-year-old male presents to the emergency department with a three-week history of fevers, weight loss and chest pain. On examination, there are splinter haemorrhages on his nails and macules on his palms consistent with janeway lesions. He had a prosthetic valve replacement one month ago.

Given the most likely diagnosis, which of the following is the most likely causative organism?
a