Identification of capsular type by the quellung
reaction and resistance genotyping by real-time PCR was performed within 1 day of sample collection for each strain.
reaction, a neglected microbiological technique.
Serotypes of all isolates were determined by the capsular quellung
reaction using antiserum purchased from the Statens Serum Institute (Copenhagen, Denmark).
Serogrouping and serotyping were performed by the quellung
reaction using antiserum provided by Statens Serum Institute (Copenhagen, Denmark) (8).
The capsular serotype of all isolates was determined by using the Quellung
reaction with antisera from the Statens Serum Institut (Copenhagen, Denmark).
All pneumococcal isolates that exhibited a positive quellung
reaction when commercial type-specific antiserum (Statens Serum Institute, Copenhagen, Denmark) was used were assigned a serotype (10).
pneumoniae isolates were serotyped by using type-specific antisera and observation of the Quellung
reaction at the Streptococcus Laboratory (Centers for Disease Control and Prevention, Atlanta, GA, USA).
These isolates, used as controls, had been serotyped by quellung
reaction at the Instituto de Salud Carlos III, Majadahonda-Madrid, Spain.