Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2006 Feb;44(2):383-8.
doi: 10.1128/JCM.44.2.383-388.2006.

Validation of a multiplex pneumococcal serotyping assay with clinical samples

Jisheng Lin  1 , Margit S Kaltoft, Angela P Brandao, Gabriela Echaniz-Aviles, M Cristina C Brandileone, Susan K Hollingshead, William H Benjamin, Moon H Nahm
Affiliations

Validation of a multiplex pneumococcal serotyping assay with clinical samples

Jisheng Lin et al. J Clin Microbiol. 2006 Feb.

Abstract

We have recently developed a rapid pneumococcal serotyping method called "multibead assay" (J. Yu et al., J. Clin. Microbiol. 43:156-162, 2005) based on a multiplexed immunoassay for capsular polysaccharides in lysates of pneumococcal cultures. The multibead assay can identify 36 serotypes (1, 2, 3, 4, 5, 6A, 6B, 7A/7F, 8, 9L/9N, 9V, 10A/10B/39/33C, 11A/11D/11F, 12A/12B/12F, 14, 15B/5C, 17F, 18C, 19A, 19F, 20, 22A/22F, 23F, and 33A/33F). More than 90% of the U.S. isolates express one of these serotypes (J. B. Robbins et al., J. Infect. Dis. 148:1136-1159, 1983). To validate the new assay, we examined 495 clinical isolates of pneumococci obtained in Brazil, Denmark, and Mexico. Pneumococci were serotyped by the Neufeld test in their countries of origin, and lysates of each strain were coded and mailed to the United States for the multibead assay at ambient temperature without any thermal protection. After breaking the code, 54 discrepancies (11% of samples) were noted, but 46 were due to nonreproducible technical problems or insufficient growth of the pneumococci. All of the isolates grew well for a second test, and therefore, the culture medium used for the multibead assay is adequate. The discrepancies persisted for eight isolates, involving the 6A, 11A, and 18C serotypes. Additional studies of the eight isolates showed that the discrepancies were due to differences in the reagents used in the multibead or Neufeld tests for these three serotypes. For instance, five isolates were typed as 6A with the Neufeld test but as nontypeable by the multibead assay. Selection of another new monoclonal antibody (Hyp6AG1) for the multibead assay resulted in all five discrepant isolates typing as 6A. This finding indicates the validity of the multibead assay and emphasizes the need to validate any new pneumococcal serotyping assay with a large number of clinical isolates from different locations. It also suggests the presence of serological subtypes among isolates expressing the 6A serotype.

PubMed Disclaimer

References

    1. Batt, S. L., B. M. Charalambous, T. D. McHugh, S. Martin, and S. H. Gillespie. 2005. Novel PCR-restriction fragment length polymorphism method for determining serotypes or serogroups of Streptococcus pneumoniae isolates. J. Clin. Microbiol. 43:2656-2661. - PMC - PubMed
    1. Brito, D. A., M. Ramirez, and H. de Lencastre. 2003. Serotyping Streptococcus pneumoniae by multiplex PCR. J. Clin. Microbiol. 41:2378-2384. - PMC - PubMed
    1. Converse, G. M., III, and H. C. Dillon, Jr. 1977. Epidemiological studies of Streptococcus pneumoniae in infants: methods of isolating pneumococci. J. Clin. Microbiol. 5:293-296. - PMC - PubMed
    1. Fedson, D. S., and D. M. Musher. 1994. Pneumococcal vaccine, p. 517-564. In S. A. Plotkin and E. A. Mortimer (ed.), Vaccines, 2nd ed. W. B. Saunders Co., Philadelphia, Pa.
    1. Fenoll, A., A. Jado, D. Vicioso, and J. Casal. 1997. Dot blot assay for the serotyping of pneumococci. J. Clin. Microbiol. 35:764-766. - PMC - PubMed

Publication types