Taenia saginata: differential diagnosis of human taeniosis by polymerase chain reaction-restriction fragment length polymorphism assay (pcr-rflp)

Taenia saginata: differential diagnosis of human taeniosis by polymerase chain reaction-restriction fragment length polymorphism assay (PCR-RFLP)

Cáris Maroni Nunes*, Ana Karina Kerche Dias, Francisca Elda Ferreira Dias, Sérgio Moraes Aoki, Henrique Borges de Paula, Luis Gustavo Ferraz Lima, José Fernando Garcia UNESP, campus Araçatuba, Department of Animal Health and Production, Rua Clóvis Pestana, 793, Jd. D. Amélia, Araçatuba, SP, Brazil, 16050-680. e-mail:[e-mail]

Abstract Taenia species differentiation in human stool is important because of its clinical and epidemiological features. To overcome limitations in differentiating human taeniid cestode by morphology, DNA analysis has become possible in the past years. In the present study we evaluated PCR coupled to restriction fragment length polymorphism to differentiate T. solium from T. saginata eggs present in fecal samples from naturally infected patients. A different pattern for T. saginata and T. solium was observed allowing differentiation between the two taeniid: a two band pattern (421 and 100 bp) for T. saginata and a three band pattern (234, 188, 99 bp) for T. solium. The lower detection limit of the PCR-RFLP using a non-infected fecal sample prepared with a given number of T. saginata eggs was 34 eggs per 2 g of stool sediment. The 521bp mtDNA fragment was detected in 8 out of 12 Taenia sp carriers (66.6%). From these, 3 showed a T. solium pattern and 5 a T. saginata pattern.

2 Index descriptors and Abbreviations: deoxyribonucleic acid (DNA); polymerase chain reaction (PCR); restriction fragment length polymorphism assay (RFLP); cestode; Taenia saginata; Taenia solium; taeniosis; fecal samples.

1. Introduction Taeniosis in humans is caused by the adult stage of Taenia solium and Taenia saginata in the Latin America and also by Taenia asiatica in Asia. Although the adult form is relatively innocuous, the larval stage of Taenia solium, in contrast, can cause severe disease in man,