QuestionSBA
QuestionChoice
This organism is associated with colorectal cancer. The patient in this question does not have colorectal cancer, therefore colonization with streptococcus bovis is unlikely. Staphylococcus aureus is the most common cause of infective endocarditis overall and is the most likely causative organism in this case.
10007582
b
Streptococcus Bovis
QuestionChoice
This is the most common cause of endocarditis in patients following prosthetic valve surgery. However, the risk of this is only within the first 2 months after surgery. We are told our patient had prosthetic valve surgery 4 months ago; therefore his chance of colonization with staph epidermis has returned to normal. Staphylococcus aureus is the most common cause of infective endocarditis overall and is the most likely causative organism in this case.
10007584
d
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. Staphylococcus aureus is the most common cause of infective endocarditis overall and is the most likely causative organism in this case.
10007585
e
Coxiella burnetii
QuestionChoice
This organism is found in dental plaque and is a common cause of endocarditis in patients with poor dental hygiene or following a dental procedure. It is also the most common cause of endocarditis in developing countries. However, staphylococcus aureus is the most common cause of infective endocarditis overall and is the most likely causative organism in this case.
10007583
c
Streptococcus viridans
QuestionChoice
This patient has the typical findings of infective endocarditis: fevers (most common), weight loss, pleuritic chest pain, night sweats, and lethargy. During the first 2 months following prosthetic valve surgery, the patient is at risk of infective endocarditis caused by staphylococcus epidermis. However, this patient had surgery 4 months ago, and the risk of staphylococcus epidermis colonization has now returned to normal. The most common causative organism of infective endocarditis overall is staphylococcus aureus, and therefore this is the most likely finding in this case.
10007581
a
Staphylococcus aureus
Concept
Chapter
2693
3710
Infective Endocarditis
Topic
134
Cardiology
14063
A 70-year-old male presents to the emergency department with a 1-month history of fever, weight loss and chest pain that is worse on inspiration. He tells you he has been feeling generally worn down with muscle and joint pains and he also noticed some night sweats.  You notice macules on the patient’s palms and soles consistent with Janeway lesions and splinter haemorrhages on the patient’s nails.

He underwent a prosthetic valve replacement 4 months ago, but is otherwise fit and well.

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