Hemophagocytic Lymphohistiocytosis Secondary to Obstructive Uropathy and Escherichia coli Bacteremia.

Hemophagocytic lymphohistiocytosis (HLH) is a rare syndrome in which widespread activation of the immune system causes multi-organ tissue damage. HLH is a serious and potentially fatal disorder characterized by excessive immune system activation. It is characterized by a dysregulation in natural killer (NK) T-cell function, causing activation of lymphocytes and histiocytes. These cells secrete a large number of inflammatory cytokines and infiltrate various tissues causing multi-organ system failure. The spectrum consists of hereditary or "primary" HLH that comprises genetically heterogeneous conditions, occurring during childhood. The secondary form presents later in life and is associated with several conditions mainly malignancy, autoimmune diseases, viral or bacterial infections, and hematological diseases. Here we present an interesting case in which a 39-year-old patient presented with a complaint of shortness of breath. He was diagnosed with obstructive uropathy in the emergency department and subsequently developed acute liver injury, acute kidney injury, Escherichia coli bacteremia, and was diagnosed with HLH with comorbid bacteremia.

Systematic evaluation of commercial susceptibility testing methods for determining the in vitro activity of daptomycin versus Staphylococcus aureus and Enterococci.

We systematically evaluated 5 methods for testing daptomycin versus 48 Enterococcus faecalis, 51 Enterococcus faecium, and 50 Staphylococcus aureus isolates using (i and ii) broth microdilution (BMD) with 50-mg/liter calcium medium supplementation (reference method) and 30-mg/liter calcium medium supplementation (BMD30 method), (iii) Etest, and (iv and v) MicroScan panel 33 using 2 methods to prepare the bacterial inoculum (MicroScan turbidity and MicroScan Prompt). Isolates were categorized as susceptible (S) or nonsusceptible (NS) based on measured MICs. Essential (± 1 dilution) agreement (EA) and categorical (S/NS) agreement (CA) for each method were compared to the reference method. For E. faecium, categorical agreement was poor between the reference method and BMD30 as well as with the three commercial methods, with frequent false-NS results (30 for BMD30, 18 for Etest, 22 for MicroScan Prompt, and 25 for MicroScan turbidity). All E. faecalis isolates were judged to be S by the reference method; two of these isolates were categorized as NS using the BMD30 method, and one was categorized as NS by all three commercial methods. All S. aureus isolates were judged to be S using all five methods. MIC values determined by the comparator methods tended to be higher than those for the reference method, especially for E. faecium isolates. EAs between the reference BMD and BMD30, Etest, MicroScan Prompt, and MicroScan turbidity were 63%, 63%, 63%, and 56%, respectively, for E. faecium, 87%, 83%, 98%, and 80%, respectively, for E. faecalis, and all 100% for S. aureus.