Proteomic analysis of the larval stage of the parasite Echinococcus granulosus: Causative agent of cystic hydatid disease

Abstract

We describe the preparation of Echinococcus granulosus metacestode protein extracts for two-dimensional electrophoresis (2-DE). Protoscoleces and hydatid fluid were prepared by precipitation using trichloroacetic acid (TCA) to remove nonprotein contaminants. Compared to the untreated control, TCA precipitation improved the 2-DE gel profile of the protoscoleces proteins. Comparison of 2-DE gels from insoluble and soluble fractions of the protoscoleces protein extract showed that most proteins are insoluble after lysis by sonication. Host serum proteins, especially albumin and globulins, caused horizontal streaking problems on the hydatid fluid 2-DE gels due to their high content in this sample. Even after the preparation of a hydatid fluid parasite enriched fraction, the high amount of bovine serum albumin and globulins made parasite-specific proteins difficult to detect by 2-DE. Despite the absence of an E. granulosus genome sequencing or expressed sequence tag (EST) projects, it was possible to identify 15 prominent protein spots from a whole protein protoscoleces 2-DE gel by peptide mass fingerprinting. These include actins, tropomyosin, paramyosin, thioredoxin reductase, antigen P-29, cyclophilin, and the heat shock proteins hsp70 and hsp20. This work demonstrates that 2-DE and PMF are important tools to identify proteins from the hydatid fluid and protoscoleces and for the comparative analysis of cysts from different hosts or between active and resting cysts.

Research Note. One minute, intraoperative assessment of the viability of hydatid cysts using a simple reagent strip test

“…Albumin is also suggested to exert functions similar to those in human plasma. These functions include its ability to maintain oncotic pressure, and to act as a transport protein (Chemale et al, 2003;Li et al, 2013). However, the micro-total protein level is equivalent to a very low level of approximately 1 -2 % in the human serum (Li et al, 1985), hence diffi cult to be visually identifi ed by a reagent strip test as reported in our study in HCF with viable PSs.…”

“…Glycogen has been reported to be present in the germinal membrane and a muco-polysaccharide is reported as a major component of both the laminated membrane and the protoscolices (Chemale et al, 2003). Moreover, it is reported that the larval stage of E. granulosus conserves greater amounts of glycogen than the adult form of the parasite.…”

“…The protein in HCF, is reported to be composed mainly of albumin, globulin and free amino acids. Most of these proteins are derived from the host proteins (Chen & Yang, 1990;Chemale et al, 2003;Aziz et al, 2011). They cross the cyst wall by both free diffusion and active transport mediated by specifi c receptors in the germinal layer (Jeffs & Arme, 1988;Huang & Xu, 1994).…”

Isolation and molecular characterization of recombinant Echinococcus granulosus P29 protein (recP29) and its assessment for the post-surgical serological follow-up of human cystic echinococcosis in young patients

“…32 Based on the biology of 14-3-3, we did not see any reason to include this antigen as a potential candidate for the present serological follow-up study. Conversely, the P29 protein first described by Gonzalez et al 29 appeared interesting by its expression being restricted to E. granulosus protoscoleces 33 and by exhibiting a good immunodiagnostic potential to detect CE in patients before surgery. 29 Our investigations now showed that a recombinant P29 also exhibits a good prognostic value in the follow-up monitoring of those cured versus non-cured CE patients who were able to develop a seropositive status against recP29 either before or shortly after diagnosis and/or initiation of a treatment protocol, respectively.…”

Serological diagnosis of cystic echinococcosis in cattle

“…However, their efficacy in the diagnosis of human hydatid disease remains low (Sarkari and Rezaei 2015). This is due to the presence of large amounts of host pro-teins in HCF reducing the specificity (Chemale et al 2003, Monteiro et al 2010. There is also a lack of standardisation of the target antigen (Sarkari and Rezaei 2015).…”