Browsing by Subject "Molecular Typing"

Filter results by typing the first few letters
Now showing 1 - 2 of 2
  • Thumbnail Image
    ItemOpen Access
    Influence of host genetics and environment on nasal carriage of staphylococcus aureus in danish middle-aged and elderly twins.
    (J Infect Dis, 2012-10) Andersen, Paal Skytt; Pedersen, Jacob Krabbe; Fode, Peder; Skov, Robert L; Fowler, Vance G; Stegger, Marc; Christensen, Kaare
    BACKGROUND: Nasal carriage is a major risk factor for Staphylococcus aureus infection. Approximately, one-quarter of adults carry S. aureus. However, the role of host genetics on S. aureus nasal carriage is unknown. METHODS: Nasal swabs were obtained from a national cohort of middle-aged and elderly Danish twins. Subjects colonized with S. aureus were identified by growth on selective plates and spa typing. A second sample was obtained from twins initially concordant for carriage. Twins found to again be colonized with S. aureus were defined as persistent carriers. RESULTS: The prevalence of S. aureus carriage among 617 twin pairs (monozygotic/dizygotic pairs: 112/505) was 26.3% (95% confidence interval [CI], 24.0%-28.9%). The concordance rate for carriage did not differ significantly between pairs of monozygotic (37.5%; 95% CI, 22.3%-53.8%) twins and same sex (24.2%; 95% CI, 15.4%-34.5%), and opposite sex (21.4%; 95% CI, 12.0%-33.4%) dizygotic twins. Despite shared childhoods, only 1 of 617 pairs was concordant with respect to lineage. Although heritability increased for S. aureus and lineage persistency, no significant heritability was detected. CONCLUSION: In this study, host genetic factors exhibited only a modest influence on the S. aureus carrier state of middle-aged and elderly individuals.
  • Thumbnail Image
    ItemOpen Access
    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.
    (Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases, 2017-08) Pericàs, JM; Messina, JA; Garcia-de-la-Mària, C; Park, L; Sharma-Kuinkel, BK; Marco, F; Wray, D; Kanafani, ZA; Carugati, M; Durante-Mangoni, E; Tattevin, P; Chu, VH; Moreno, A; Fowler, VG; Miró, JM; International Collaboration on Endocarditis Microbiology Investigators

    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.