Case # 1. A 54/M with chronic malaise, low back pain and new-onset heart failure secondary to subacute infected endocarditis (IE) secondary to Abiotrophia defectiva.
Taken from: http://medicine.creighton.edu/medschool/WebAtlas/secure/id/strep1/images/Strep%20NDS.jpg
1. Abiotrophia defectiva and Granulicatella sp are nutritionally-variant Streptococcus (NVS) that require pyridoxal for growth on culture. They are part of the normal oral, gastrointestinal, upper respiratory and urogenital flora. They are known to cause IE but they can also lead to primary bacteremia in patients with hematologic malignancy.
2. Compared with IE caused by viridans group Streptococcus, IE associated with NVS is usually characterized by smaller vegetation but with greater incidence of septic embolization. It also carries higher failure, relapse, and mortality rates.
3. IE associated with NVS is treated with ampicillin and gentamicin (or vancomycin plus gentamicin for penicillin-allergic patients) similar to Enterococcus-associated IE.
4. Abiotrophia defectiva shows in vitro susceptibility to vancomycin, rifampin, clindamycin, chloramphenicol, erythromycin, and levofloxacin. On the other hand, Granulicatella sp. are more likely to be resistant to penicillin and cephalosporins compared with Abiotrophia.
Case # 2. An 18/M with h/o bilateral lung transplantation for idiopathic bronchiolitis obliterans 2 years ago and poorly adherent to prednisone, tacrolimus, mycophenolate, and atovaquone presented with acute and progressive respiratory failure secondary to acute rejection; respiratory multiplex PCR tested positive for rhinovirus/enterovirus.
1. From last week's discussion, we know that the detection of rhinovirus/enterovirus using the multiplex PCR test is a clue to the presence of enterovirus D68. Because the patient had respiratory failure, further sequencing was done on the isolate. The isolate was identified as human rhinovirus 36.
2. Rhinovirus, unlike enterovirus, is tropic to the upper and not the lower respiratory tract. However, rarely, it can cause lower respiratory tract disease. Infection with rhinovirus is not associated with acute lung rejection in one case series.
Case # 3. A 30 year old man with well controlled HIV infection on HAART presented with acute rash that involved his bilateral palms and soles as well as acute Bell's palsy.
Taken from: http://upload.wikimedia.org/wikipedia/commons/2/29/Treponema_pallidum.jpg
1. Bell's palsy occurs in secondary and tertiary forms of syphilis hence, performing a lumbar puncture to rule out neurosyphilis is warranted.
2. This patient had a normal head CT scan and lumbar puncture revealed 0 white cells and normal total protein. The absence of white cells in the CSF can rule out neurosyphilis but a more definitive test (although not standardized) that rules this out is a negative CSF FTA. The latter is usually ordered when the clinical suspicion for neurosyphilis remains in the presence of mild CSF pleocytosis and a negative CSF VDRL.
3. Read more about other unusual manifestations of secondary syphilis (i.e. gastropathy, hepatitis, Bell's palsy, aseptic meningitis ) here.
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