CIBICI   14215
CENTRO DE INVESTIGACION EN BIOQUIMICA CLINICA E INMUNOLOGIA
Unidad Ejecutora - UE
artículos
Título:
Characterization of 14 serotype variants of the pneumococcal Spain9V-3 clone spread in Cordoba, Argentina
Autor/es:
ALBARRACIN ORIO, ANDREA; CORTES, PAULO; TREGNAGHI, MIGUEL; PIÑAS, GERMÁN; ECHENIQUE, JOSE
Revista:
JOURNAL OF MEDICAL MICROBIOLOGY
Editorial:
Society of General Microbiology
Referencias:
Lugar: London; Año: 2008 vol. 57 p. 992 - 999
ISSN:
0022-2615
Resumen:
The penicillin-resistant Spain9V-3 clone of Streptococcus pneumoniae is widespread
and presents different serotype variants originated by recombination of the
capsular genes. In this work, the genetic relatedness of 29 invasive
pneumococci isolated from the central region of Argentina, was assessed by
MLST. All the penicillin-resistant isolates belonged to a serotype 14 variant
of the Spain9V-3 clone. This clone was predominant, suggesting that
it was responsible of the penicillin-resistance spread in our region.
Interestingly, the Argentinean serotype 14 variant was differentiated from the
European one by the pbp1a gene, suggesting
a different recombinational replacement of the capsular genes. The putative
recombinational sites were analyzed, resulting in the proximal crossover point
being clearly localized in the spr0309
gene, with the distal site being restricted to the recU gene, confirming a different recombinational event. The
analysis of the dexB, cpsB, aliA and pbp1a genes from
our strains showed a high homology with the corresponding genes of the Spain14-5
clone, suggesting that the capsular genes were provided by this international
clone. The analysis of the genetic polymorphisms of the pbp1a (1473-1922 region) and spr0309
(1-790 region) genes is proposed as an epidemiological tool to help recognize
the Argentinean serotype 14 variant of the Spain9V-3 clone. On the
other hand, a PCR-BOX and MLST analysis of serotype 14 strains isolated from
other provinces revealed a divergent epidemiology of the Argentinean variant,
suggesting a non-recent dissemination in our paediatric population.We consider that this molecular epidemiology work will
be a reference for monitoring the evolution of the serotype 14 variants of
Spain9V-3, the emergence of new clones and the impact of pneumococcal
vaccination programs in Argentina.