Disease isolates of Streptococcus pseudopneumoniae and non-typeable S. pneumoniae presumptively identified as atypical S. pneumoniae in Spain

• Published in: PloS one Vol. 8; no. 2; p. e57047
• Main Authors: Rolo, Dora, S Simões, Alexandra, Domenech, Arnau, Fenoll, Asunción, Liñares, Josefina, de Lencastre, Hermínia, Ardanuy, Carmen, Sá-Leão, Raquel
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 21-02-2013; Public Library of Science (PLoS)
• Subjects: Analysis; Antibacterial agents; Antibiotics; Bile; Bilis; Biology; Carbon dioxide; Carbon dioxide atmospheric concentrations; Chronic obstructive pulmonary disease; Clinical isolates; Disease; Erythromycin; Female; Gene polymorphism; Genes; Genetic diversity; Genetic polymorphisms; Genetics; Genotype; Health aspects; Humans; Identification; Infeccions per pneumococs; Laboratories; Male; Medicine; Microbial Sensitivity Tests; Multilocus Sequence Typing; Pathogens; Penicillin; Phenotype; Phylogeny; Pneumococcal Infections; Pneumococs; Pneumonia; Polymorphism; PspA protein; Respiratory tract; Restriction fragment length polymorphism; RNA; rRNA 16S; Solubility; Spain; Streptococcal Infections - diagnosis; Streptococcus; Streptococcus - classification; Streptococcus - drug effects; Streptococcus - genetics; Streptococcus infections; Streptococcus pneumonia; Streptococcus pneumoniae; Streptococcus pneumoniae - classification; Streptococcus pneumoniae - drug effects; Streptococcus pneumoniae - genetics; Spain; New York; United States > US; Portugal
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0057047

We aimed to obtain insights on the nature of a collection of isolates presumptively identified as atypical Streptococcus pneumoniae recovered from invasive and non-invasive infections in Spain. One-hundred and thirty-two isolates were characterized by: optochin susceptibility in ambient and CO(2)-enriched atmosphere; bile solubility; PCR-based assays targeting pneumococcal genes lytA, ply, pspA, cpsA, Spn9802, aliB-like ORF2, and a specific 16S rRNA region; multilocus sequence analysis; and antimicrobial susceptibility. By multilocus sequence analysis, 61 isolates were S. pseudopneumoniae, 34 were pneumococci, 13 were S. mitis, and 24 remained unclassified as non-pneumococci. Among S. pseudopneumoniae isolates, 51 (83.6%) were collected from respiratory tract samples; eight isolates were obtained from sterile sources. High frequency of non-susceptibility to penicillin (60.7%) and erythromycin (42.6%) was found. Only 50.8% of the S. pseudopneumoniae isolates displayed the typical optochin phenotype originally described for this species. None harbored the cpsA gene or the pneumococcal typical lytA restriction fragment length polymorphism. The Spn9802 and the specific 16S rRNA regions were detected among the majority of the S. pseudopneumoniae isolates (n = 59 and n = 49, respectively). The ply and pspA genes were rarely found. A high genetic diversity was found and 59 profiles were identified. Among the S. pneumoniae, 23 were capsulated and 11 were non-typeable. Three non-typeable isolates, associated to international non-capsulated lineages, were recovered from invasive disease sources. In conclusion, half of the atypical pneumococcal clinical isolates were, in fact, S. pseudopneumoniae and one-fourth were other streptococci. We identified S. pseudopneumoniae and non-typeable pneumococci as cause of disease in Spain including invasive disease.