Browsing by Author "Tong, Steven YC"

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    CAMERA2 - combination antibiotic therapy for methicillin-resistant Staphylococcus aureus infection: study protocol for a randomised controlled trial.
    (Trials, 2016-03-31) Tong, Steven YC; Nelson, Jane; Paterson, David L; Fowler, Vance G; Howden, Benjamin P; Cheng, Allen C; Chatfield, Mark; Lipman, Jeffrey; Van Hal, Sebastian; O'Sullivan, Matthew; Robinson, James O; Yahav, Dafna; Lye, David; Davis, Joshua S; CAMERA2 study group and the Australasian Society for Infectious Diseases Clinical Research Network
    BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) bacteraemia is a serious infection resulting in 20-50 % 90-day mortality. The limitations of vancomycin, the current standard therapy for MRSA, make treatment difficult. The only other approved drug for treatment of MRSA bacteraemia, daptomycin, has not been shown to be superior to vancomycin. Surprisingly, there has been consistent in-vitro and in-vivo laboratory data demonstrating synergy between vancomycin or daptomycin and an anti-staphylococcal β-lactam antibiotic. There is also growing clinical data to support such combinations, including a recent pilot randomised controlled trial (RCT) that demonstrated a trend towards a reduction in the duration of bacteraemia in patients treated with vancomycin plus flucloxacillin compared to vancomycin alone. Our aim is to determine whether the addition of an anti-staphylococcal penicillin to standard therapy results in improved clinical outcomes in MRSA bacteraemia. METHODS/DESIGN: We will perform an open-label, parallel-group, randomised (1:1) controlled trial at 29 sites in Australia, New Zealand, Singapore, and Israel. Adults (aged 18 years or older) with MRSA grown from at least one blood culture and able to be randomised within 72 hours of the index blood culture collection will be eligible for inclusion. Participants will be randomised to vancomycin or daptomycin (standard therapy) given intravenously or to standard therapy plus 7 days of an anti-staphylococcal β-lactam (flucloxacillin, cloxacillin, or cefazolin). The primary endpoint will be a composite outcome at 90 days of (1) all-cause mortality, (2) persistent bacteraemia at day 5 or beyond, (3) microbiological relapse, or (4) microbiological treatment failure. The recruitment target of 440 patients is based on an expected failure rate for the primary outcome of 30 % in the control arm and the ability to detect a clinically meaningful absolute decrease of 12.5 %, with a two-sided alpha of 0.05, a power of 80 %, and assuming 10 % of patients will not be evaluable for the primary endpoint. DISCUSSION: Key potential advantages of adding anti-staphylococcal β-lactams to standard therapy for MRSA bacteraemia include their safety profile, low cost, and wide availability. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02365493 . Registered 24 February 2015.
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    Panton-Valentine leukocidin is not the primary determinant of outcome for Staphylococcus aureus skin infections: evaluation from the CANVAS studies.
    (PLoS One, 2012) Tong, Amy; Tong, Steven YC; Zhang, Yurong; Lamlertthon, Supaporn; Sharma-Kuinkel, Batu K; Rude, Thomas; Ahn, Sun Hee; Ruffin, Felicia; Llorens, Lily; Tamarana, Ganesh; Biek, Donald; Critchley, Ian; Fowler, Vance G
    The impact of Panton-Valentine leukocidin (PVL) on the severity of complicated skin and skin structure infections (cSSSI) caused by Staphylococcus aureus is controversial. We evaluated potential associations between clinical outcome and PVL presence in both methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) isolates from patients enrolled in two large, multinational phase three clinical trials assessing ceftaroline fosamil for the treatment of cSSSI (the CANVAS 1 and 2 programs). Isolates from all microbiologically evaluable patients with monomicrobial MRSA or MSSA infections (n = 473) were genotyped by PCR for pvl and underwent pulsed-field gel electrophoresis (PFGE). Genes encoding pvl were present in 266/473 (56.2%) isolates. Infections caused by pvl-positive S. aureus were associated with younger patient age, North American acquisition, and presence of major abscesses (P<0.001 for each). Cure rates of patients infected with pvl-positive and pvl-negative S. aureus were similar overall (93.6% versus 92.8%; P = 0.72), and within MRSA-infected (94.5% vs. 93.1%; P = 0.67) and MSSA-infected patients (92.2% vs. 92.7%; P = 1.00). This finding persisted after adjustment for multiple patient characteristics. Outcomes were also similar when USA300 PVL+ and non-USA300 PVL+ infections were compared. The results of this contemporary, international study suggest that pvl presence was not the primary determinant of outcome in patients with cSSSI due to either MRSA or MSSA.