#$%^&*AU2008224343B220120510.pdf#####ABSTRACT This invention relates to a polypeptide fragment which comprises an amino acid encoded by a member of the esat-6 gene. A member of the esat-6 gene family is 5 defined as gene encoding a small protein and that two such genes are arranged next to each other on the genome and that at least one of the gene products has an amino acid sequence identity to either Rv3874, Rv3875, or Rv0288 of at least 15%.