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The pneumococcal enzyme-linked immunosorbent assay (ELISA) reference standard serum, lot 89SF, has been in use since 1990 and was replaced in 2013 with a new reference standard, 007sp, that is projected to be available for the next 25 years. 007sp was generated under an FDA-approved clinical protocol; 278 adult volunteers were immunized with the 23-valent unconjugated polysaccharide vaccine Pneumovax II, and a unit of blood was obtained twice from each immunized subject within 120 days following immunization. Pooled serum was prepared from the plasma of 262 subjects, filled at 6 ml per vial, and lyophilized. Five independent laboratories participated in bridging the serotype-specific IgG assignments for 89SF to the new reference standard, 007sp, to establish equivalent reference values for 13 pneumococcal capsular serotypes (1,3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, and 23F) by using the WHO reference ELISA. In a second study involving three laboratories, a similar protocol was used to assign weight-based IgG concentrations in micrograms per ml to 007sp of seven serotypes (8, 10A, 11A, 12F, 15B, 22F, and 33F) also present in the 23-valent pneumococcal unconjugated polysaccharide vaccine. In addition, the IgG assignments for a 12-member WHO quality control (QC) serum panel were also extended to cover these seven serotypes. Agreement was excellent, with a concordance correlation coefficient (r c ) of >0.996 when each laboratory was compared to the assigned values for the 12 WHO QC serum samples. There are four remaining pneumococcal serotypes (2, 9N, 17F, and 20) found in Pneumovax II for which IgG assignments exist for 89SF and remain to be bridged. AStreptococcus pneumoniae Human Reference Standard, lot 89SF, greatly facilitated the standardization of enzyme-linked immunosorbent assay (ELISA) methodologies during a critical period when the first pneumococcal polysaccharide conjugate vaccines were being evaluated for licensure. Lot 89SF was used in serotype-specific ELISAs designed to measure IgG antibody specific for individual pneumococcal capsular polysaccharides. Serotype-specific weight-based values for IgG, IgA, and IgM were originally derived for serotypes 1,3,4,5, 6B, 7F, 9V,14, 18C, 19F, and 23F for lot 89SF by Quataert et al. (1). Assignments for the additional serotypes in the 23-valent pneumococcal polysaccharide vaccine were subsequently bridged from the assignments for the original 11 serotypes (2). Because of dwindling supplies of 89SF, a new reference standard, 007sp, was developed and described in 2011 (3). This serum was generated under an FDA-approved clinical protocol in which 278 adult volunteers were immunized with the 23-valent unconjugated polysaccharide vaccine Pneumovax II. A unit of blood was obtained twice from each immunized subject within 120 days following immunization. Pooled serum was prepared from the plasma, filled at 6 ml per vial, and lyophilized. Five independent laboratories participated in bridging the serotype-specific IgG assignments for 89SF to the new reference sta...

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The adherence of six Candida species to fibrin clots was studied using a simple, in vitro technique. Yeast suspensions were incubated with fibrin clots and the number of adherent organisms quantified as follows: after washing, the clots were subjected to vortex mixing and the number of CFU's which subsequently grew on Sabourauds medium were counted. Adhesion was directly proportional to the concentration of Candida species in the suspension (r = 0.99 p less than 0.001). C. albicans and C. tropicalis exhibited marked adherence whereas C. krusei, C. gulliermondi and C. glabrata adhered less readily. C. parapsilosis was intermediate in its ability to adhere.

The pneumococcal enzyme-linked immunosorbent assay (ELISA) reference standard serum, lot 89SF, had been in use since 1990 and was replaced with a new reference standard serum, 007sp, in 2013. This serum was generated under an FDA-approved clinical protocol where 278 adult volunteers were immunized with the 23-valent unconjugated polysaccharide vaccine Pneumovax II and a unit of blood was obtained twice within 120 days following immunization. Pooled serum was prepared from the plasma, filled at 6 ml per vial, and lyophilized. Five independent laboratories participated in bridging the serotype-specific IgG assignments of 89SF to 007sp to establish equivalent reference values for 13 pneumococcal capsular serotypes (1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, 23F) using the WHO reference ELISA. A subsequent follow-up study established equivalent reference values for an additional seven serotypes (8, 10A, 11A, 12F, 15B, 22F, 33F). In this study, three laboratories assigned weight-based IgG concentrations in micrograms per milliliter of serum to 007sp for four additional serotypes: 2, 9N, 17F, and 20A. This study completes the assignment of serotypes for 89SF to 007sp. In addition, the IgG antibody assignments for a 12-member WHO quality control (QC) serum panel were extended to cover the four additional serotypes. Agreement was excellent, with a concordance correlation coefficient (r c ) of Ͼ0.996 when values from each laboratory were compared to the assigned values for the 12 WHO QC sera. The 007sp preparation has replaced 89SF as the pneumococcal reference standard. Sufficient quantities of 007sp are projected to be available for the next 25 years. KEYWORDS conjugate, pneumococcus, vaccines AStreptococcus pneumoniae human reference serum, lot 89SF, greatly facilitated the standardization of enzyme-linked immunosorbent assay (ELISA) methods during a critical period when the first pneumococcal polysaccharide conjugate vaccines were being evaluated for licensure. The standard serum was used in serotype-specific ELISAs designed to measure IgG antibody specific for individual pneumococcal capsular polysaccharides. Serotype-specific weight-based values for IgG, IgA, and IgM were originally derived for serotypes 1,3,4,5, 6B, 7F, 9V, 14, 18C, 19F, and 23F for lot 89SF by Quataert et al. (1). Assignments for the additional serotypes in the 23-valent pneumococcal polysaccharide vaccine were subsequently bridged from the assignments for the original 11 serotypes (2). Due to dwindling supplies of 89SF, a new reference standard serum, 007sp, was developed and described in 2011 (3). This serum was generated under an FDA-approved clinical protocol in which 278 adult volunteers were immunized with the 23-valent unconjugated polysaccharide vaccine Pneumovax II and a