Identification of staphylococci by Phoenix: validation of a new protocol and comparison with Vitek 2

Because of their frequent isolation in the routine laboratory and their increasing clinical significance, fast and accurate species identification of staphylococci may be required, this can only be achieved by automated systems A total of 147 clinical isolates (52 Staphylococcus aureus, 50 Staphylococcus epidermidis, and 45 other coagulase-negative staphylococci [CoNS]) were first identified by molecular methodology and then comparatively tested by Vitek 2 (new colorimetric identification card) and Phoenix using the novel 0 25 McFarland and the standard 0 50 McFarland inoculum protocols All S aureus isolates were accurately identified Vitek 2 identified correctly all S epidermidis and 93 3% of the other CoNS, whereas the respective rates were 86% and 82 2% for Phoenix's standard and 92% and 82 2% for the novel protocol It appears that both systems provide excellent identification of S aureus, but Vitek 2 recognizes CoNS species more accurately than Phoenix The 0 25 McFarland protocol does not Improve system performance (C) 2010 Elsevier Inc All rights reserve

Two successfully treated cases of Staphylococcus lugdunensis endocarditis

Prosthetic valve and pacemaker lead endocarditis by Staphylococcus lugdunensis remain very rare, while the former is associated with an ominous prognosis Two cases involving a prosthetic aortic valve and a pacemaker lead, respectively, are reported Despite disease seventy and delayed diagnosis, patients recovered fully with combined antimicrobial and surgical treatment (C) 2010 Elsevier Inc All rights reserve

Two successfully treated cases of Staphylococcus lugdunensis endocarditis

Prosthetic valve and pacemaker lead endocarditis by Staphylococcus lugdunensis remain very rare, while the former is associated with an ominous prognosis. Two cases involving a prosthetic aortic valve and a pacemaker lead, respectively, are reported. Despite disease severity and delayed diagnosis, patients recovered fully with combined antimicrobial and surgical treatment. © 2010 Elsevier Inc

Influence of vancomycin minimum inhibitory concentration on the outcome of methicillin-susceptible Staphylococcus aureus left-sided infective endocarditis treated with antistaphylococcal β-lactam antibiotics: a prospective cohort study by the International Collaboration on Endocarditis

Objectives Left-sided methicillin-susceptible Staphylococcus aureus (MSSA) endocarditis treated with cloxacillin has a poorer prognosis when the vancomycin minimum inhibitory concentration (MIC) is ≥1.5 mg/L. We aimed to validate this using the International Collaboration on Endocarditis cohort and to analyse whether specific genetic characteristics were associated with a high vancomycin MIC (≥1.5 mg/L) phenotype. Methods All patients with left-sided MSSA infective endocarditis treated with antistaphylococcal β-lactam antibiotics between 2000 and 2006 with available isolates were included. Vancomycin MIC was determined by Etest as either high (≥1.5 mg/L) or low (<1.5 mg/L). Isolates underwent spa typing to infer clonal complexes and multiplex PCR for identifying virulence genes. Univariate analysis was performed to evaluate the association between in-hospital and 1-year mortality, and vancomycin MIC phenotype. Results Sixty-two cases met the inclusion criteria. Vancomycin MIC was low in 28 cases (45%) and high in 34 cases (55%). No significant differences in patient demographic data or characteristics of infection were observed between patients with infective endocarditis due to high and low vancomycin MIC isolates. Isolates with high and low vancomycin MIC had similar distributions of virulence genes and clonal lineages. In-hospital and 1-year mortality did not differ significantly between the two groups (32% (9/28) vs. 27% (9/34), p 0.780; and 43% (12/28) vs. 29% (10/34), p 0.298, for low and high vancomycin MIC respectively). Conclusions In this international cohort of patients with left-sided MSSA endocarditis treated with antistaphylococcal β-lactams, vancomycin MIC phenotype was not associated with patient demographics, clinical outcome or virulence gene repertoire

Influence of vancomycin minimum inhibitory concentration on the outcome of methicillin-susceptible Staphylococcus aureus left-sided infective endocarditis treated with antistaphylococcal β-lactam antibiotics: a prospective cohort study by the International Collaboration on Endocarditis

International audienceObjectivesLeft-sided methicillin-susceptible Staphylococcus aureus (MSSA) endocarditis treated with cloxacillin has a poorer prognosis when the vancomycin minimum inhibitory concentration (MIC) is ≥1.5 mg/L. We aimed to validate this using the International Collaboration on Endocarditis cohort and to analyse whether specific genetic characteristics were associated with a high vancomycin MIC (≥1.5 mg/L) phenotype.MethodsAll patients with left-sided MSSA infective endocarditis treated with antistaphylococcal β-lactam antibiotics between 2000 and 2006 with available isolates were included. Vancomycin MIC was determined by Etest as either high (≥1.5 mg/L) or low (<1.5 mg/L). Isolates underwent spa typing to infer clonal complexes and multiplex PCR for identifying virulence genes. Univariate analysis was performed to evaluate the association between in-hospital and 1-year mortality, and vancomycin MIC phenotype.ResultsSixty-two cases met the inclusion criteria. Vancomycin MIC was low in 28 cases (45%) and high in 34 cases (55%). No significant differences in patient demographic data or characteristics of infection were observed between patients with infective endocarditis due to high and low vancomycin MIC isolates. Isolates with high and low vancomycin MIC had similar distributions of virulence genes and clonal lineages. In-hospital and 1-year mortality did not differ significantly between the two groups (32% (9/28) vs. 27% (9/34), p 0.780; and 43% (12/28) vs. 29% (10/34), p 0.298, for low and high vancomycin MIC respectively).ConclusionsIn this international cohort of patients with left-sided MSSA endocarditis treated with antistaphylococcal β-lactams, vancomycin MIC phenotype was not associated with patient demographics, clinical outcome or virulence gene repertoire