Accuracy of phenotypic and genotypic testing for identification of Streptococcus pneumoniae and description of Streptococcus pseudopneumoniae sp. nov.
We have identified an unusual group of viridans group streptococci that resemble Streptococcus pneumoniae. DNA-DNA homology studies suggested that a subset of these isolates represent a novel species that may be included in the S. oralis-S. mitis group of viridans group streptococci. We suggest that this novel species be termed Streptococcus pseudopneumoniae. A combination of phenotypic and genetic reactions allows its identification. S. pseudopneumoniae strains do not have pneumococcal capsules, are resistant to optochin (inhibition zones, less than 14 mm) when they are incubated under an atmosphere of increased CO2 but are susceptible to optochin (inhibition zones, >14 mm) when they are incubated in ambient atmospheres, are not soluble in bile, and are positive by the GenProbe AccuProbe Pneumococcus test. The bile solubility test is more specific than the optochin test for identification of S. pneumoniae. Genetic tests for pneumolysin (ply) and manganese-dependent superoxide dismutase (sodA) and identification tests with a commercial probe, AccuProbe Pneumococcus, do not discriminate between the new species and S. pneumoniae.
Department of Microbiology, Division of Pathology and Laboratory Medicine, Queen Elizabeth II Health Sciences Centre, Halifax, Nova Scotia, Canada. j.arbique@ns.sympatico.ca
Judy C
JC
Arbique
Claire
C
Poyart
Patrick
P
Trieu-Cuot
Gilles
G
Quesne
Maria da Glória S
Mda G
Carvalho
Arnold G
AG
Steigerwalt
Roger E
RE
Morey
Delois
D
Jackson
Ross J
RJ
Davidson
Richard R
RR
Facklam
D015373:Bacterial Typing Techniques; D001646:Bile; D003470:Culture Media; D004275:DNA, Ribosomal / Q000032:analysis; D005838:Genotype; D006801:Humans; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D010641:Phenotype; D010802:Phylogeny; D011803:Quinine / Q000031:analogs & derivatives* / Q000494:pharmacology; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012995:Solubility; D013045:Species Specificity; D013296:Streptococcus pneumoniae / Q000145:classification* / Q000235:genetics* / Q000254:growth & development; D034363:Viridans Streptococci / Q000145:classification* / Q000235:genetics* / Q000254:growth & development
D003470:Culture Media; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; C017303:ethylhydrocupreine; D011803:Quinine