Recombinant α- and β-tubulin from Echinococcus granulosus: expression, purification and polymerization

Benzimidazole Resistance-Associated Mutations in the β-tubulin Gene of Hookworms: A Systematic Review

There is a growing number of reports on the occurrence of benzimidazole resistance-associated single nucleotide polymorphisms (SNPs) in the β-tubulin isotype 1 gene of various helminths of veterinary, and public health concerns. However, a comprehensive analysis of their occurrence, and their contributions to conferring benzimidazole resistance among hookworms has yet to be done. The objectives of this systematic review are to summarize and synthesize peer-reviewed evidence on the occurrence of these resistance-associated mutations in hookworms, document their geographical distribution, and assess their contributions to conferring phenotypic resistance. Three databases were systematically searched using specific keywords. Research that assessed the occurrence of benzimidazole resistance-associated SNPs in hookworms, papers that reported the geographical distribution of these SNPs, and studies that investigated the SNPs' resistance-associated phenotypic effects were included in the review. Research that was not done in hookworms, papers not in the English language, and literature reviews and book chapters were excluded. Critical appraisal checklists were used to determine the risk of bias in the selected papers. Data were extracted from the selected studies and analyzed. PROSPERO Systematic Review Protocol Registration No.: CRD42024510924. A total of 29 studies were included and analyzed. Of these, four were conducted in a laboratory setting, eight described the development and validation of SNP detection methods, and the remaining 17 involved field research. Seven SNP-induced amino acid substitutions at four loci were reported among several hookworm species: Q134H, F167Y, E198A, E198K, E198V, F200Y, and F200L. SNPs have been reported in isolates occurring in the United States, Canada, Brazil, Haiti, Australia, New Zealand, Kenya, Ghana, Mozambique, and Tanzania. Resistance mutations have not been reported in Asia. E198A and F200L were reported in Ancylostoma ceylanicum with laboratory-induced resistance. F167Y and Q134H conferred resistance in A. caninum, as revealed by in vitro investigations and field assessments. There is insufficient peer-reviewed evidence to prove the association between SNP occurrence and resistance. Mutations in the β-tubulin isotype 1 gene confer benzimidazole resistance in A. caninum and A. ceylanicum, but similar evidence is lacking for other human hookworms. Understanding benzimidazole resistance through further research can better inform treatment, prevention, and control strategies.

Characterization of the B-Cell Epitopes of Echinococcus granulosus Histones H4 and H2A Recognized by Sera From Patients With Liver Cysts

Cystic echinococcosis (CE) is a zoonotic disease worldwide distributed, caused by the cestode Echinococcus granulosus sensu lato (E. granulosus), with an incidence rate of 50/100,000 person/year and a high prevalence in humans of 5-10%. Serology has variable sensitivity and specificity and low predictive values. Antigens used are from the hydatid fluid and recombinant antigens have not demonstrated superiority over hydatid fluid. A cell line called EGPE was obtained from E. granulosus sensu lato G1 strain from bovine liver. Serum from CE patients recognizes protein extracts from EGPE cells with higher sensitivity than protein extracts from hydatid fluid. In the present study, EGPE cell protein extracts and supernatants from cell colonies were eluted from a protein G affinity column performed with sera from 11 CE patients. LC-MS/MS proteomic analysis of the eluted proteins identified four E. granulosus histones: one histone H4 in the cell extract and supernatant, one histone H2A only in the cell extract, and two histones H2A only in the supernatant. This differential distribution of histones could reflect different parasite viability stages regarding their role in gene transcription and silencing and could interact with host cells. Bioinformatics tools characterized the linear and conformational epitopes involved in antibody recognition. The three-dimensional structure of each histone was obtained by molecular modeling and validated by molecular dynamics simulation and PCR confirmed the presence of the epitopes in the parasite genome. The three histones H2A were very different and had a less conserved sequence than the histone H4. Comparison of the histones of E. granulosus with those of other organisms showed exclusive regions for E. granulosus. Since histones play a role in the host-parasite relationship they could be good candidates to improve the predictive value of serology in CE.