[Abstract]  [Full Text]  [PDF]

Jun Li¹, Wen-Bao Zhang¹ and Donald P. McManus^1*

¹ Molecular Parasitology Laboratory, Australian Centre for International and Tropical Health and Nutrition, Queensland Institute of Medical Research. 300 Herston Road, Herston, Brisbane, Queensland 4029. Australia.

* To whom correspondence should be addressed: Donald P. McManus, Molecular Parasitology Laboratory, Australian Centre for International and Tropical Health and Nutrition, Queensland Institute of Medical Research. 300 Herston Road, Herston, Brisbane, Queensland 4029. Australia. Phone: 61-7-3362 0401. Fax: 61-7-3362 0104. Email: donM@qimr.edu.au

Biol. Proced. Online 2004;6:67-77. doi:10.1251/bpo74
Submitted: April 12, 2004; Accepted: April 27, 2004; Published: May 10, 2004.

Indexing terms: Echinococcus; Recombinant proteins; Blotting, Western.

Abbreviations: CE, cystic echinococcosis; AE, alveolar echinococcosis; NCC, neurocysticercosis; Schist, schistosomiasis; Others, other infections/clinical presentations; Healthy, uninfected controls.

Three cDNAs, termed EpC1, TPxEg and EgG5, were isolated by immunoscreening from an Echinococcus granulosus cDNA library. The recombinant phages exhibited strong reactivity with sera from humans with confirmed cystic echinococcosis (CE) and with sera from mice infected with E. granulosus oncospheres. The cDNAs were subcloned into a pET vector, expressed as fusion proteins tagged with GST and affinity purified against the GST tag. Of the three recombinant proteins, EpC1 achieved the highest performance for serodiagnosis of CE in Western blot analysis using a panel of clinically defined human sera to initially address the sensitivity and specificity of the molecules. The protein yielded an overall sensitivity of 92.2% and specificity of 95.6%, levels unprecedented taking into account the large panel of 896 human sera that were tested. The strategy used may also prove suitable for improved immunodiagnosis of other parasitic infections.