Resumen:
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.