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Soluble-protein and antigenic heterogeneity in axenic Blastocystis hominis isolates: pathogenic implications
M D Lanuza1, J A Carbajal, J Villar
1Departamento de Microbiología, Facultad de Medicina, Valencia, Spain.
Abstract:
The protein profile and the antigenic cross-reactivity of 18 axenic isolates of Blastocystis hominis obtained from symptomatic patients with chronic diarrhea (14 isolates) showing no evidence of parasitic etiology and from patients with acute diarrhea attributable in 2 cases to Salmonella spp. were analyzed. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of soluble proteins showed the existence of a common profile composed of 31 bands, with molecular weights ranging between 24 and >200 kDa, and minor differences in the proteins of 149, 118, 106, 50, 48, 47, and 30 kDa. These differences allowed us to classify the strains into three related patterns (I-III). In an indirect immunofluorescence assay, all strains were serologically identical, but two related antigenic groups (1 and 2) were found in double-immunodiffusion and Western-blot studies. The isolates of protein patterns I and II belonging to antigenic group 1 were isolated from patients with chronic diarrhea, whereas the four isolates from patients with acute diarrhea were clustered in protein pattern III and in antigenic group 2. These results confirm the protein and antigenic heterogeneity of B. hominis and the existence of demes with different pathogenic roles.
Insights
Blastocystis hominis exhibits significant protein and antigenic diversity. These variations suggest distinct subtypes may play different roles in causing diarrhea in patients.
Area of Science:
- Microbiology
- Immunology
- Parasitology
Background:
- Blastocystis hominis is a common intestinal parasite.
- Its role in causing diarrhea is debated due to observed heterogeneity.
Purpose of the Study:
- To analyze the protein profiles and antigenic cross-reactivity of Blastocystis hominis isolates.
- To investigate potential correlations between specific subtypes and clinical symptoms.
Main Methods:
- Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) for protein profiling.
- Indirect immunofluorescence assay (IFA), double-immunodiffusion, and Western blotting for antigenic analysis.
Main Results:
- A common protein profile with 31 bands was observed across 18 isolates.
- Minor protein variations allowed classification into three patterns (I-III).
- Two antigenic groups (1 and 2) were identified, with distinct associations between protein patterns, antigenic groups, and diarrhea types (chronic vs. acute).
Conclusions:
- Blastocystis hominis displays significant protein and antigenic heterogeneity.
- Distinct subtypes (demes) of Blastocystis hominis may possess different pathogenic potentials.
- Further research is needed to elucidate the specific roles of these subtypes in gastrointestinal diseases.