The complete nucleotide sequences (open reading frame regions only) for all full length pilF nucleotide sequences, deposited by Roig et al. (2010), and encompassing GenBank accession numbers FJ756476eFJ756489 and FJ899603eFJ899608, were aligned using clustalW (Thompson et al., 1994). A region of the pilF genes (approximate position 481e601) was analysed using primer express software from DNASTAR (Madison, WI, USA). Initial sequence alignment comparisons identified a variable region, at approximate positions 534e571 in the pilF gene that demonstrated significant polymorphism for the design of an appropriate TaqMan
probe (Fig. 1), targeting a sequence specific to human serumresistant strains. The probe and primers were subsequently assessed for species as well as strain specificity using a BLAST search against publically available databases (Table 1).