Week 2: Bloodstream Infections

Hello everyone, hope you are all having a nice week.  In Tuesday’s Infectious Diseases lecture we discussed bloodstream infections.  Endocarditis is an important topic when discussing bloodstream infections, so I have decided to devote more attention to the subject.  Endocarditis is defined as the inflammation of the heart’s inner lining which can lead to damage of the heart valves.  The duration of this condition is less than six weeks.  Endocarditis is the classic example of intravascular bacteremia and can involve normal or prosthetic valves.  If endocarditis is suspected, two to three cultures should be collected over one to two hours.  Endocarditis is treated with Penicillin, aminoglycoside, antifungal agents (should a fungal species such as Candida or Aspergillus be the root cause of the endocarditis), and surgery. 

Many different bacterial agents may involved in endocarditis, including the HACEK organisms, opportunistic organisms found as normal flora in the oral cavity but may become involved in periodontal disease, endocarditis and other diseases.  Haemophilus, the “H” in HACEK, is the most prevalent HACEK agent involved in endocarditis.  Other HACEK organisms involved in endocarditis include Aggregatibacter actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, and Kingella.  Capnocytophaga, Bartonella, S. aureus, S. epidermidis, S. pneumoniae, S. pyogenes, N. gonorrhoeae, and P. aeruginosa are additional bacteria that may be involved in endocarditis.  Viridans streptococci, Enterococcus (other group D strep), anaerobic and microaerophilic strep, as well as the HACEK organisms may be involved in subacute bacterial endocarditis, a condition that lasts six weeks or longer.  Like endocarditis, subacute endocarditis is treated with Penicillin and aminoglycoside.

           The following is an entertaining yet informational video concerning endocarditis.  Enjoy! http://www.youtube.com/watch?v=Udgbbz1_qe0&feature=related