new_n_lost
Politically InCorrect
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A 25-year-old man presents with a high fever and generalized malaise. His condition deteriorates so rapidly that his friends decide to take him to the emergency department 24 hours after the onset of symptoms. He has a history of intravenous drug abuse. A test for anti-HIV antibodies is negative. Physical examination reveals a systolic murmur and echocardiography shows bulky vegetations attached to the tricuspid valve leaflets.
Which of the following microorganisms will be most likely be isolated from this patient's blood cultures?
A. Candida albicans
B. Hemophilus influenzae
C. Staphylococcus aureus
D. Staphylococcus epidermidis
E. Viridans (a-hemolytic) streptococci
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FORUM RULES-- Those who believe in telekinesis, raise my hand. I get enough exercise just by pushing my luck --P4U World.." The pure and simple truth is rarely pure and never simple."
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| po
Forum Elite
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C.
http://pathweb.uchc.edu/eAtlas/CV/642.htm
but whats this?->IVDA cases. Most have normal valves." Left sided lesions predominate", but "right sided valves commonly affected".
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| usmlefever
Forum Senior
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thanks for the w site.
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| silver
Forum Guru
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C. Staphylococcus aureus
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Every disaster hides an opportunity.
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| Luckyall
Forum Guru
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Staph. aureus is MCC of Inf Endocard. in IV drug abusers.
Staphylococcus epidermidis is MCC in prosthetic devices !
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| rock
Forum Elite
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C
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| dc-mako
Forum Newbie
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c
S
taph A
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| new_n_lost
Politically InCorrect
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FORUM RULES-- Those who believe in telekinesis, raise my hand. I get enough exercise just by pushing my luck --P4U World.." The pure and simple truth is rarely pure and never simple."
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| new_n_lost
Politically InCorrect
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The correct answer is C.
The patient has a fever and is extremely ill. The most important clue to the diagnosis is the presence of bulky vegetations on the tricuspid valve, indicating that he has infective endocarditis. On the basis of the rapid clinical course, this is likely a case of acute infective endocarditis. The diagnosis of this condition must be confirmed by blood cultures, which are also necessary to determine bacterial antibiotic sensitivity. S. aureus (commonly present on the skin) is the most frequent etiologic agent of infective endocarditis in intravenous drug abusers. It commonly affects the tricuspid valve. Because of its high virulence, S. aureus-related endocarditis follows an acute course and may lead to death within a few days.
The causative agents of infective endocarditis differ depending on host factors. Fungal organisms, such as Candida albicans (choice A), may cause infective endocarditis in severely immunosuppressed patients, such as those with AIDS.
A minority of cases of infective endocarditis are caused by a number of normal commensals in the oral cavity, i.e., the "HACEK" group: Hemophilus (choice B), Actinobacillus, Cardiobacterium, Eikenella, and Kingella.
S. epidermidis (choice D) and other coagulase-negative staphylococci tend to produce endocarditis in recipients of prosthetic valves.
Viridans streptococci (choice E) are the most frequent agents causing endocarditis in previously abnormal valves, such as those damaged by rheumatic disease, or congenitally abnormal valves.
Coagulase-negative staphylococci and viridans (a-hemolytic) streptococci are less virulent than S. aureus and are thus associated with a subacute (more prolonged) clinical course and a better prognosis
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FORUM RULES-- Those who believe in telekinesis, raise my hand. I get enough exercise just by pushing my luck --P4U World.." The pure and simple truth is rarely pure and never simple."
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