Detección de los genes rrgc y srtc-3 codificantes del pilus tipo 1 y su distribución en cepas de Streptococcus pneumoniae resistentes a los antimicrobianos aisladas en niños con enfermedad invasiva de Lima, Perú

Abstract

The development of resistant strains has hampered the treatment of neumococcic invasive deseases in children. The polysacharid-conjugated vaccines have shown to be a partial and temporal solution, therefore the studies are now directed to know other celular components targets for vaccines, such as pilus 1 type. In the present study, the detection for PCR of the genes rrgC y srtC-3 was used as an indicator of pilus 1 presence in 41 strains of Streptococcus pneumoniae resistant to antimrobials, causing invasive diseases in children up to ten years old in Lima, Peru, from 2006 to 2008. The frequency of pilus 1 was 51%, and was similar in both meningitis strains versus non-meningitis strains (p=0.53) and in vaccinable versus non-vaccinable strains ((p=1.00). In some pilus strains it was not posible to detect either the gene rrgC or the gene srtC-3, suggesting that those strains might have different sequences from the initially described for these genes. Therefore it is recommended that in epidemiological studies the combine detection of more than one gene, avoiding the lack of knowledge of genetic variants of the pathogenecity island rlrA. It was found a high frequency of pilus 1 in strains with serotypes nonvaccinable (50%). Those results suggest that the addition of proteins related to pilus 1 type to the available polyscharid-conjugated vaccinable formulations could help to reduce the number of invasive infections and the resistance to the antimicrobials related to strains of S. pneumoniae in Lima. Peru, children