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Updated: Aug 9, 2026

Capsular Serotyping of Streptococcus pneumoniae Using the Quellung Reaction
Published on: February 24, 2014
Identifying non-capsulate strains of Streptococcus pneumoniae isolated from eyes
Abstract:
Over six months 10 biochemically and physiologically atypical strains of Streptococcus pneumoniae were isolated from eye swabs. Conventional methodology showed that these strains possessed characteristics of both S pneumoniae and other alpha haemolytic streptococci. The use of sodium dodecyl sulphate - polyacrylamide gel electrophoresis (SDS-PAGE) enabled us to characterise these strains as S pneumoniae. Loss of the capsule seemed to be associated with atypical biochemical properties.
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