ABSTRACT
The performance of the eazyplex® EHEC complete (Amplex) for the detection of Shiga toxin genes in stool samples was evaluated. The assay performed well in distinguishing between stx1 and stx2 but suboptimal sensitivity may limit its use to complementary testing rather than primary diagnosis of Shiga toxin-producing Escherichia coli infections.
Subject(s)
Escherichia coli Infections/diagnosis , Feces/microbiology , Molecular Diagnostic Techniques/methods , Shiga Toxin 1/genetics , Shiga Toxin 2/genetics , Bacteriological Techniques/methods , Enterohemorrhagic Escherichia coli/isolation & purification , Shiga Toxin , Shiga-Toxigenic Escherichia coliABSTRACT
BACKGROUND: Staphylococcus aureus bacteraemia is a disease with varying presentation, ranging from uncomplicated to life-threatening infections. In S. aureus bacteraemia, a high load of bacterial DNA in blood has been linked to mortality. We hypothesized that a high DNA load would also be linked to the presence of sepsis, and to high C-reactive protein (CRP) and lymphopaenia, indicating inflammation and immunosuppression. METHODS: Twenty-seven patients with culture-proven S. aureus bacteraemia, 13 (48%) with sepsis and six (22%) non-survivors, were enrolled in a prospective study. Blood samples were collected on days 0, 1-2, 3-4, 6-8, 13-15 and 26-30, and subjected to droplet digital PCR targeting the nuc gene to determine the nuc DNA load. RESULTS: nuc DNA was detected on days 0-2 in 22 patients (81%), and on days 6-8 in three patients (all non-survivors). The nuc DNA load on days 1-2 was significantly elevated in patients with sepsis (median 2.69 versus 1.32 log10 copies/mL; p = .014) and in non-survivors (median 2.5 versus 1.0 log10 copies/mL; p = .033). Patients with a high nuc DNA load (>3.0 log10 copies/mL) on days 1-2 had significantly elevated CRP levels at all timepoints, and significantly decreased lymphocyte counts on days 0, 1-2, 13-15 and 26-30. CONCLUSIONS: Our results indicate that a high initial load of S. aureus DNA in blood is associated with sepsis, mortality and persistent immune dysregulation in S. aureus bacteraemia patients. Further studies are needed to define the role of bacterial DNA load monitoring in the management of S. aureus bacteraemia.
Subject(s)
Bacteremia/blood , DNA, Bacterial/blood , Staphylococcal Infections/blood , Adult , Aged , Aged, 80 and over , Bacteremia/immunology , Bacteremia/mortality , Bacteremia/physiopathology , Bacterial Proteins/genetics , C-Reactive Protein/metabolism , Endocarditis, Bacterial/microbiology , Female , Humans , Male , Micrococcal Nuclease/genetics , Middle Aged , Polymerase Chain Reaction/methods , Real-Time Polymerase Chain Reaction , Staphylococcal Infections/immunology , Staphylococcal Infections/mortality , Staphylococcal Infections/physiopathology , Staphylococcus aureus , Young AdultABSTRACT
We compared the performance of the BD Max enteric parasite panel to routine microscopy and an in-house PCR for the detection of Giardia intestinalis, Entamoeba histolytica, and Cryptosporidium spp. The enteric parasite panel showed good specificity for all targets and good sensitivity for E. histolytica and Cryptosporidium spp. Sensitivity for G. intestinalis with the BD Max enteric parasite panel was equivalent to that with microscopy.
