Identification of less-common Streptococcus pneumoniae serotypes by a multiplex PCR-based reverse line blot hybridization assay

Abstract

We developed a multiplex PCR-based reverse line blot (mPCR/RLB) assay to identify 50 uncommon pneumococcal serotypes. In combination with a previously described mPCR/RLB assay (3), all 90 pneumococcal serotypes can be identified individually (32 serotypes) or, because of predictable cross-reactions, to within small groups of two to five related serotypes (58 serotypes), which can be distinguished using serotype-specific antisera.

FIG. 1.

mPCR/RLB results for a representative sample of 43 clinical isolates (see Table 1 for descriptions and specificities of the probes listed on the left). Conventional serotype-mPCR/RLB results for the isolates shown, from left to right, are 43, 7B, 9A,* 9L,* 9V,* 19B, 11B, 11C, 12A,* 15F, 16F, 17A, 18F,* 19B, 19C, 21, 24F, 24A, 24B, 11B, 27, 28F, 28A, 32F, 32A, 33A,* 33B, 33B, 33F,* 35C, 36, 37,* 39, 40, 41F, 41A, 44,* 43, 7B, 45, 46,* 47F, and 47A. Isolates marked with asterisks belong to one of 40 serotypes identified by our original mPCR/RLB assay (3) and were not amplified in this assay.