Q: After Staphylococcus spp, which of the following organism is the most common cause of infected (mycotic) arterial aneurysm?

A) Salmonella 
B) Treponema pallidum
C) Mycobacterium spp
D) Coxiella burnetii 
E) Candida



Answer: A

Staphylococcus spp and Salmonella spp, are so far the most common cause of mycotic aneurysm. Though list of organisms are long, but for reasons not fully understood Salmonella is easily prone to bacteremic seeding of atherosclerotic plaque.



References:

1. Brossier J, Lesprit P, Marzelle J, et al. New bacteriological patterns in primary infected aorto-iliac aneurysms: a single-centre experience. Eur J Vasc Endovasc Surg 2010; 40:582.

2. Hsu RB, Tsay YG, Wang SS, Chu SH. Surgical treatment for primary infected aneurysm of the descending thoracic aorta, abdominal aorta, and iliac arteries. J Vasc Surg 2002; 36:746.

3. Gomes MN, Choyke PL, Wallace RB. Infected aortic aneurysms: a changing entity. Ann Surg. 1992;215:435-442.