6 research outputs found
Influence of Vancomycin Minimum Inhibitory Concentration on the Outcome of Methicillin-Susceptible Staphylococcus aureus Left-Sided Infective Endocarditis Treated with Anti-staphylococcal Beta-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
Implementation of Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry in Routine Clinical Laboratories Improves Identification of Coagulase-Negative Staphylococci and Reveals the Pathogenic Role of Staphylococcus lugdunensis
Methicillin-susceptible Staphylococcus aureus endocarditis isolates are associated with clonal complex 30 genotype and a distinct repertoire of enterotoxins and adhesins
Heterogeneous Vancomycin-Intermediate Susceptibility Phenotype in Bloodstream Methicillin-Resistant Staphylococcus aureus Isolates from an International Cohort of Patients with Infective Endocarditis: Prevalence, Genotype, and Clinical Significance.
BACKGROUND: The significance of heterogeneous vancomycin-intermediate
Staphylococcus aureus (hVISA) is unknown. Using a multinational collection of
isolates from methicillin-resistant S. aureus (MRSA) infective endocarditis (IE),
we characterized patients with IE with and without hVISA, and we genotyped the
infecting strains. METHODS: MRSA bloodstream isolates from 65 patients with
definite IE from 8 countries underwent polymerase chain reaction (PCR) for 31
virulence genes, pulsed-field gel electrophoresis, and multilocus sequence
typing. hVISA was defined using population analysis profiling. RESULTS: Nineteen
(29.2%) of 65 MRSA IE isolates exhibited the hVISA phenotype by population
analysis profiling. Isolates from Oceania and Europe were more likely to exhibit
the hVISA phenotype than isolates from the United States (77.8% and 35.0% vs
13.9%; P < .001). The prevalence of hVISA was higher among isolates with a
vancomycin minimum inhibitory concentration of 2 mg/L (P = .026). hVISA-infected
patients were more likely to have persistent bacteremia (68.4% vs 37.0%; P =
.029) and heart failure (47.4% vs 19.6%; P = .033). Mortality did not differ
between hVISA- and non-hVISA-infected patients (42.1% vs 34.8%, P = .586). hVISA
and non-hVISA isolates were genotypically similar. CONCLUSIONS: In these
analyses, the hVISA phenotype occurred in more than one-quarter of MRSA IE
isolates, was associated with certain IE complications, and varied in frequency
by geographic region