Four Cases of Taenia saginata Infection with an Analysis of COX1 Gene

Human taeniases had been not uncommon in the Republic of Korea (=Korea) until the 1980s. The prevalence decreased and a national survey in 2004 revealed no Taenia egg positive cases. However, a subsequent national survey in 2012 showed 0.04% (10 cases) prevalence of Taenia spp. eggs suggesting its resurgence in Korea. We recently encountered 4 cases of Taenia saginata infection who had symptoms of taeniasis that included discharge of proglottids. We obtained several proglottids from each case. Because the morphological features of T. saginata are almost indistinguishable from those of Taenia asiatica, molecular analyses using the PCR-RFLP and DNA sequencing of the cytochrome c oxidase subunit 1 (cox1) were performed to identify the species. The PCR-RFLP patterns of all of the 4 specimens were consistent with T. saginata, and the cox1 gene sequence showed 99.8-100% identity with that of T. saginata reported previously from Korea, Japan, China, and Cambodia. All of the 4 patients had the history of travel abroad but its relation with contracting taeniasis was unclear. Our findings may suggest resurgence of T. saginata infection among people in Korea.

Morphologic and Genetic Identification of Taenia Tapeworms in Tanzania and DNA Genotyping of Taenia solium

Species identification of Taenia tapeworms was performed using morphologic observations and multiplex PCR and DNA sequencing of the mitochondrial cox1 gene. In 2008 and 2009, a total of 1,057 fecal samples were collected from residents of Kongwa district of Dodoma region, Tanzania, and examined microscopically for helminth eggs and proglottids. Of these, 4 Taenia egg positive cases were identified, and the eggs were subjected to DNA analysis. Several proglottids of Taenia solium were recovered from 1 of the 4 cases. This established that the species were T. solium (n=1) and T. saginata (n=3). One further T. solium specimen was found among 128 fecal samples collected from Mbulu district in Arusha, and this had an intact strobila with the scolex. Phylegenetic analysis of the mtDNA cox1 gene sequences of these 5 isolates showed that T. saginata was basal to the T. solium clade. The mitochondrial cox1 gene sequences of 3 of these Tanzanian isolates showed 99% similarity to T. saginata, and the other 2 isolates showed 100% similarity to T. solium. The present study has shown that Taenia tapeworms are endemic in Kongwa district of Tanzania, as well as in a previously identified Mbulu district. Both T. solium isolates were found to have an "African/Latin American" genotype (cox1).

Fecal specimens preparation methods for PCR diagnosis of human taeniosis

Com o intuito de utilizar a Reação em Cadeia pela Polimerase (PCR) como método de diagnóstico diferencial da teníase humana, avaliaram-se alguns protocolos de preparação e extração de DNA de ovos de Taenia saginata presentes em amostras de fezes de paciente naturalmente infectado. O DNA obtido após extração com fenol/clorofórmio/álcool isoamílico ou DNAzol® teve que ser purificado antes da PCR para que fosse possível a amplificação dos fragmentos de 170 pb e 600 pb desejados. Com o kit QIAmp DNA stool mini kit® tal purificação não foi necessária. Os melhores resultados foram observados após o tratamento prévio das amostras com pérolas de vidro, tanto quando da utilização de fenol/clorofórmio/álcool isoamílico, quando de DNAzol® ou QIAmp DNA stool mini kit®.