ABSTRACT
Staphylococcus argenteus is a globally distributed cause of human infection, but diagnostic laboratories misidentify this as Staphylococcus aureus. We determined whether there is clinical utility in distinguishing between the two. A prospective cohort study of community-onset invasive staphylococcal sepsis was conducted in adults at four hospitals in northeast Thailand between 2010 and 2013. Of 311 patients analysed, 58 (19%) were infected with S. argenteus and 253 (81%) with S. aureus. Most S. argenteus (54/58) were multilocus sequence type 2250. Infection with S. argenteus was more common in males, but rates of bacteraemia and drainage procedures were similar in the two groups. S. argenteus precipitated significantly less respiratory failure than S. aureus (5.2% versus 20.2%, adjusted OR 0.21, 95% CI 0.06-0.74, p 0.015), with a similar but non-significant trend for shock (6.9% versus 12.3%, adjusted OR 0.46, 95% CI 0.15-1.44, p 0.18). This did not translate into a difference in death at 28 days (6.9% versus 8.7%, adjusted OR 0.80, 95% CI 0.24-2.65, p 0.72). S. argenteus was more susceptible to antimicrobial drugs compared with S. aureus, and contained fewer toxin genes although pvl was detected in 16% (9/58). We conclude that clinical differences exist in association with sepsis due to S. argenteus versus S. aureus.
Subject(s)
Community-Acquired Infections/epidemiology , Community-Acquired Infections/pathology , Sepsis/epidemiology , Sepsis/pathology , Staphylococcal Infections/epidemiology , Staphylococcal Infections/pathology , Staphylococcus/isolation & purification , Adult , Aged , Community-Acquired Infections/microbiology , Community-Acquired Infections/mortality , Drug Resistance, Bacterial , Female , Hospitals , Humans , Male , Microbial Sensitivity Tests , Middle Aged , Prospective Studies , Respiratory Insufficiency/epidemiology , Respiratory Insufficiency/etiology , Sepsis/complications , Sepsis/microbiology , Shock/epidemiology , Shock/etiology , Staphylococcal Infections/microbiology , Staphylococcal Infections/mortality , Staphylococcus/classification , Staphylococcus/drug effects , Survival Analysis , Thailand/epidemiology , Virulence Factors/geneticsABSTRACT
We examined whether quantitative biofilm formation and/or lipopolysaccharide type of Burkholderia pseudomallei was associated with relapsing melioidosis. We devised a 1:4 nested case-control study in which both cases and controls were drawn from a cohort of patients with primary melioidosis. Paired isolates from 80 patients with relapse and single isolates from 184 patients without relapse were tested. Relapse was associated with biofilm formation of the primary infecting isolate (conditional OR 2.03; 95% CI 1.27-3.25; p 0.003), but not with lipopolysaccharide type (p 0.74). This finding highlights the importance of biofilm formation in relapsing melioidosis.
