Last data update: May 06, 2024. (Total: 46732 publications since 2009)
Records 1-3 (of 3 Records) |
Query Trace: Bolcen SJ[original query] |
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Development of a standardized opsonophagocytosis killing assay for group B Streptococcus and assessment in an interlaboratory study
Leung S , Collett CF , Allen L , Lim S , Maniatis P , Bolcen SJ , Alston B , Patel PY , Kwatra G , Hall T , Thomas S , Taylor S , Le Doare K , Gorringe A . Vaccines (Basel) 2023 11 (11) The placental transfer of antibodies that mediate bacterial clearance via phagocytes is likely important for protection against invasive group B Streptococcus (GBS) disease. A robust functional assay is essential to determine the immune correlates of protection and assist vaccine development. Using standard reagents, we developed and optimized an opsonophagocytic killing assay (OPKA) where dilutions of test sera were incubated with bacteria, baby rabbit complement (BRC) and differentiated HL60 cells (dHL60) for 30 min. Following overnight incubation, the surviving bacteria were enumerated and the % bacterial survival was calculated relative to serum-negative controls. A reciprocal 50% killing titer was then assigned. The minimal concentrations of anti-capsular polysaccharide (CPS) IgG required for 50% killing were 1.65-3.70 ng/mL (depending on serotype). Inhibition of killing was observed using sera absorbed with homologous CPS but not heterologous CPS, indicating specificity for anti-CPS IgG. The assay performance was examined in an interlaboratory study using residual sera from CPS-conjugate vaccine trials with international partners in the Group B Streptococcus Assay STandardisatiON (GASTON) Consortium. Strong correlations of reported titers between laboratories were observed: ST-Ia r = 0.88, ST-Ib r = 0.91, ST-II r = 0.91, ST-III r = 0.90 and ST-V r = 0.94. The OPKA is an easily transferable assay with accessible standard reagents and will be a valuable tool to assess GBS-specific antibodies in natural immunity and vaccine studies. |
Nocardia cyriacigeorgica infections attributable to unlicensed cosmetic procedures -- an emerging public health problem?
Apostolou A , Bolcen SJ , Dave V , Jani N , Lasker BA , Tan CG , Montana B , Brown JM , Genese CA . Clin Infect Dis 2012 55 (2) 251-3 We describe an outbreak of Nocardia cyriacigeorgica soft-tissue infections attributable to unlicensed cosmetic injections and the first report using MLST sequence data for determining Nocardia strain relatedness in an outbreak. All eight cases identified had a common source exposure and required hospitalization, surgical debridement, and prolonged antimicrobial therapy. |
Gordonia bronchialis bacteremia and pleural infection: case report and review of the literature
Johnson JA , Onderdonk AB , Cosimi LA , Yawetz S , Lasker BA , Bolcen SJ , Brown JM , Marty FM . J Clin Microbiol 2011 49 (4) 1662-6 Gordonia species are aerobic actinomycetes recently recognized as causing human disease, often in the setting of intravascular catheter-related infections. We describe a case of Gordonia bronchialis bacteremia and pleural space infection in the absence of an indwelling intravascular catheter, and review the breadth of reported infections with this emerging pathogen. |
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