DNA Differential Diagnosis of Taeniasis and Cysticercosis by Multiplex PCR

Abstract

Multiplex PCR was established for differential diagnosis of taeniasis and cysticercosis, including their causative agents. For identification of the parasites, multiplex PCR with cytochrome c oxidase subunit 1 gene yielded evident differential products unique for Taenia saginata and Taenia asiatica and for American/African and Asian genotypes of Taenia solium with molecular sizes of 827, 269, 720, and 984 bp, respectively. In the PCRbased detection of tapeworm carriers using fecal samples, the diagnostic markers were detected from 7 of 14 and 4 of 9 T. solium carriers from Guatemala and Indonesia, respectively. Test sensitivity may have been reduced by the length of time (up to 12 years) that samples were stored and/or small sample volumes (ca. 30 to 50 mg). However, the diagnostic markers were detected by nested PCR in five worm carriers from Guatemalan cases that were found to be negative by multiplex PCR. It was noteworthy that a 720 bp-diagnostic marker was detected from a T. solium carrier who was egg-free, implying that it is possible to detect worm carriers and treat before mature gravid proglottids are discharged. In contrast to T. solium carriers, 827-bp markers were detected by multiplex PCR in all T. saginata carriers. The application of the multiplex PCR would be useful not only for surveillance of taeniasis and cysticercosis control but also for the molecular epidemiological survey of these cestode infections.Taenia solium, Taenia saginata, and Taenia asiatica are known as causative agents of taeniasis in humans. T. solium also causes cysticercosis in humans. In particular, neurocysticercosis caused by larval T. solium cysticerci developed in the central nervous system is the most serious disease characterized by diverse neurologic symptoms, most commonly epileptic seizure (5,20). In contrast to cysticercosis, taeniasis is relatively innocuous, with the adult stages of these cestodes infecting the small intestine of humans and causing a few specific symptoms, such as abdominal pain and nausea (15). However, gravid proglottids filled with eggs expelled from tapeworm carriers serve as a new source of infection for intermediate hosts, particularly in developing countries where sanitary conditions are poor. Therefore, early detection and adequate treatment of taeniasis is important for the prevention of cysticercosis infections. Furthermore, reliable epidemiological information for use in the effective control of taeniasis or cysticercosis, including accurate tools for parasite identification, is needed. To date, proglottids and scolices expelled from tapeworm carriers or cysticerci collected from intermediate hosts have been identified morphologically. In Asian regions, however, T. saginata and T. asiatica are frequently confused due to their morphological similarities. Moreover, a recent study demonstrates that two distinct genotypes of T. solium exist, i.e., Asian and American/African genotypes (14). DNA differential diagnosis is considered very useful for the accurate identification of human taeniid...

Caracterização das lesões por Cysticercus bovis, na inspeção post mortem de bovinos, pelos exames macroscópico, histopatológico e pela reação em cadeia da polimerase (PCR)

“…Em contrapartida, neste trabalho foi possível demonstrar que a extração de DNA de cisticercos viáveis, por fervura, é um método exeqüível, com resultados satisfató-rios. Não há dúvidas que a extração por métodos químicos (Gonzáles et al 2000, 2002b, Yamasaki 2004, Jardim 2006) produzem resultados convenientes, porém são métodos caros, podem demandar tempo, além de um possível risco para a saúde e para o meio ambiente, devido a alguns reagentes. Pode-se acrescentar que as várias lavagens e centrifugações, exigidas por tais méto-dos, aumentam o risco de contaminação do template e perda de DNA.…”

“…Yamasaki et al (2004) admitiram que a sensibilidade da técnica da PCR pudesse ϐicar reduzida, dependendo das condições e do tempo de armazenamento e também da quantidade de amostra usada.…”

Neurocysticercosis as Solitary Parenchymal Lesion Confirmed by Mitochondrial Deoxyribonucleic Acid Sequence Analysis-Case Report-

“…1,3) The larvae can cause cyst formation in any tissue, including the central nervous system (CNS). Cysticercosis in the CNS, or neurocysticercosis, is a very common disease in Central and South America, Asia, and Africa, [1][2][3][4][5][6][9][10][11][12][13][14] although a few cases have been reported in Japan. 7,8) Patients with neurocysticercosis often present with varied and non-specific symptoms including seizures and focal neurological deficits.…”

“…5,6,9,10) Mitochondrial deoxyribonucleic acid (DNA) sequence analysis of the specimens can also provide a definitive diagnosis. 13,14) However, very few cases have been examined using these methods. 5,6,9,10,13,14) Here we present a case of neurocysticercosis identified by MR spectroscopy and confirmed as solitary parenchymal lesion caused by the Asian genotype of T. solium by mitochondrial DNA sequence analysis.…”

“…3) The clinical diagnosis of neurocysticercosis has been based on the patient history, radiographical findings, and pathological confirmation. [1][2][3][4][5][6][7][8][9][10][11][12][13][14] Magnetic resonance (MR) imaging is also valuable for the diagnosis. However, T 1 -weighted MR imaging with gadolinium may show neurocysticercosis as a solitary parenchymal lesion, which cannot be differentiated from other solitary lesions including other types of parasites and tuberculosis.…”