Molecular characterization of new serotype 14 variants of the Spain9V-3 clone spread in Cordoba, Argentina.

ALBARRACIN ORIO, ANDREA; PAULO CORTES; GERMÁN PIÑAS; JOSÉ ECHENIQUE

Rosario, Argentina

Congreso; XLII Reunión Anual de la Sociedad Argentina de Investigación Bioquímica y Biología Molecular; 2006

SAIB

We have analyzed by MLST the genetic background of 17 invasive pneumococci isolated from pediatric patients in Cordoba City, Argentina. All the penicillin-resistant isolates were serotype 14 variants of the Spain9V-3. To investigate whether our strains derivate from other serotype 14 variants described previously, some specific genes were analyzed. Interestingly, the Cordoba variants were differentiated from the Uruguayan/European variants by the pbp1a gene (1473-1922 region), suggesting a different recombinational replacement of the capsular genes. To probe this hypothesis, we tried to identify the recombinational sites and the proximal crossover point was clearly localized into the spr0309 gene, and the distal site was restricted to the recU gene, indicating 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 14cps genes were provided by this international clone. On the other hand, the PCR-BOX analysis and the capacity to transfer penicillin/cefotaxime resistance by pbps genes revealed a divergent local epidemiology of the Cordoba variants, suggesting a non-recent dissemination in our pediatric population. Despite the geographical proximity, the Cordoba variants showed a different clonal origin to those isolated in Uruguay.