Cross-reactivity of current serogroup 6 factor sera from Statens Serum Institut with the recently described pneumococcal serotype 6d.

摘要

A recent study by Jacobs et al. (3) examined the specificity of a newly introduced pneumococcal capsule-specific antiserum (factor serum 6d) manufactured by Statens Serum Institut (SSI) in Denmark. The factor serum 6d was designed to be specific for serotype 6C, a newly described pneumococcal se-rotype (5), and was to complement factor sera 6b and 6c, which are designed to be specific for pneumococcal serotypes 6A and 6B, respectively. While Jacobs et al. confirmed the designed specificity of the factor serum 6d for serotype 6C using the standard Quellung reaction, the study did not examine the specificity of the factor serum for the novel 6D serotype, which was previously predicted (2) but was only recently found in nature (1, 4). We have therefore investigated the specificity of the currently available serogroup 6 factor sera with serotype 6D using the standard Quellung reaction, an agglutination assay, and a flow cytometric assay.