Estructura de mosaico del cromosoma bacteriano: Islas patogénicas

the pathogenic islands (pais) are bacterial dna segments that carry one or more genes of virulence, which have been acquired in block from an outsourcing. the genome of a pathogen usually represents a mosaic between these new acquired islands and a relatively old dna. the pais are identified by their difference in the percentage of g+c content related to the average of the chromosome and by other characteristics, which suggest their acquisition through movable genetic elements. genes for an wide range of virulence determinants are associate with pais, including which codify for certain mechanisms to resist the defenses, factors of colonization, acquisition of nutrients and toxins. the study and knowledge of the pais provide important evidences to the biology of the pathogenic bacteria. in a future, the products of the pais will be able to represent targets for the antimicrobial therapy, vaccines and diagnostic tools.