Diversity of pneumococcal surface protein A among prevalent clones causing invasive disease in adult patients in Barcelona (19972006)
Abstract number: P1331
Rolo D., Ardanuy C., Martín R., Liñares J.
Objectives: Pneumococcal surface protein A (PspA) is a recognised major virulence factor and it has been classified into family 1 (Fam1: clades 1 and 2), family 2 (Fam2: clades 3, 4 and 5), and family 3 (Fam3: clade 6). After PCV7 vaccination, serotype/clone replacement has been observed worldwide. The aim of this study was to determine the distribution of Fam and clade of PspA among invasive representative S. pneumoniae (Spn) strains from adult patients from the Hospital Universitari de Bellvitge, Barcelona, in order to establish the possible use of PspA as a vaccine candidate.
Methods: In our Hospital, 90% (n = 395) of the invasive pneumococci isolated from adult patients from 1997 to 2006 were studied by PFGE (SmaI) and serotyping. A total of 72% of the studied strains were grouped into 28 major PFGE patterns. A selection of 49 invasive pneumococci, representative of those dominant PFGE patterns, was characterised by MLST (ST) and PspA. Clade-defining region of PspA was amplified by PCR, sequenced and compared with published data.
Results: PspA sequence analysis revealed that 30 strains belonged to Fam2, 18 strains to Fam1 and one strain was non-typeable. No Fam3 strains were detected. Association between serotypes and Fam/clade was not found, however a relationship between Fam/clade and ST was observed:
Fam1/clade1 (n = 37) was associated with Spain6B-2, Spain145, England149, Colombia519, Sweden128, Sweden140, Netherlands833, ST97-serotype 10, ST1026-serotype 20, ST311-serotype 23F and ST433-serotype 22 clones
Fam1/clade2 (n = 3) was associated with ST2217-serotype 35F clone
Fam2/clade3 (n = 39) was associated with Spain23F-1, Spain9V-3, Netherlands331, Netherlands7F-39, ST110-serotype 18C, ST62-serotype 11A, ST202-serotype 19A, ST247-serotype 4, ST30-serotype 16, ST67-serotype 9N and ST88-serotype 19F clones
Fam2/clade4 (n = 3) was associated with Sweden15A-25, Netherlands18C-36, ST42-serotype 23A, ST2312-serotype 8 and ST558-serotype 35B clones
Fam2/clade5 (n = 3) was associated with Poland6B-20, ST260-serotype 3 and ST989-serotype 12 clones.
Conclusions: A clear association between PspA (Fam/clade) and genotype (ST) was found, whereas PspA (Fam/clade) was independent of serotype. The most important Fam/clades of PspA among invasive pneumococci isolated from adult patients in our geographical area were Fam2/clade3 and Fam1/clade1. Since international clones contain PspA Fam1 and Fam2, both families should be included in a future PspA based vaccine.
|Session name:||18th European Congress of Clinical Microbiology and Infectious Diseases|
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