Ke. Morrison et al., Confirmation of psaA in all 90 serotypes of Streptococcus pneumoniae by PCR and potential of this assay for identification and diagnosis, J CLIN MICR, 38(1), 2000, pp. 434-437
The gene encoding the pneumococcal surface adhesin A (PsaA) protein, psaA w
as confirmed in all Streptococcus pneumoniae serotypes by a newly developed
PCR (psaA PCR) assay. Eighty-nine of the 90 serotypes amplified produced a
n 838-bp fragment; the exception nas a serotype 16F strain acquired from th
e American Type Culture Collection (ATCC). analysis of 20 additional 16F st
rains from the United States and Brazil showed that the gene was amplified
in all 16F strains, implying that the serotype 16F ATCC strain must be a va
riant. The specificity of the assay was verified by the lack of signal from
analysis of heterologous bacterial species (n = 30) and genera (n = 14), i
ncluding viridans group streptococci, The potential of the assay far clinic
al application was shown by its ability to detect pneumococci in culture-po
sitive nasopharyngeal specimens. Demonstration of psaA in all 90 serotypes
and lack of amplification of heterologous organisms suggest that this assay
could be a useful tool for detection of pneumococci and diagnosis of disea
se.