Differential diagnosis of Taenia saginata and Taenia solium infection by PCR

We have designed species-specific oligonucleotides which permit the differe ntial detection of two species of cestodes, Taenia saginata and Taenia soli um. The oligonucleotides contain sequences established for two previously r eported, noncoding DNA fragments cloned from a genomic library of T. sagina ta. The first, which is T. saginata specific (fragment HDP1), is a repetiti ve sequence with a 53-bp monomeric unit repeated 23 times in direct tandem along the 1,272-bp fragment. From this sequence the two oligonucleotides th at were selected (oligonucleotides PTs4F1 and PTs4R1) specifically amplifie d genomic DNA (gDNA) from T. saginata but not T. solium or other related ce stodes and had a sensitivity down to 10 pg of T. saginata gDNA. The second DNA fragment (fragment HDP2; 3,954 bp) hybridized to both T. saginata and T . solium DNAs and was not a repetitive sequence. Three oligonucleotides (ol igonucleotides PTs7S35F1, PTs7S35F2, and PTs7S35R1) designed from the seque nce of HDP2 allowed the differential amplification of gDNAs from T. saginat a, T. solium, and Echinococcus granulosus in a multiplex PCR, which exhibit s a sensitivity of 10 pg.