Identification of heterogeneity in human isolates of Giardia lamblia by isoenzyme studies.
Electrophoretic mobility patterns of six enzymes, viz. alkaline phosphatase E.C. 3.1.3.1., acid phosphatase E.C. 3.1.3.2., malic enzyme E.C. 1.1.1.40., phosphoglucomutase E.C. 2.7.5.1., isocitrate dehydrogenase E.C. 1.1.1.42., glucose-6-phosphate dehydrogenase E.C. 1.1.1.49 of two axenically cultured human Giardia lamblia isolated from India (PD-1 and PD-2) and one strain from Portland, Oregon, USA (P-1) were compared using polyacrylamide gel electrophoresis (PAGE). Based on the difference in the mobility patterns of the enzymes phosphoglucomutase, isocitrate dehydrogenase and malic enzyme, the PD-1 and PD-2 isolates appeared to be quite different from P-1. In the present study, the isocitrate dehydrogenase and alkaline phosphatase enzymes were used for the first time for differentiation of Giardia isolates. In the case of PD-1, two alkaline phosphatase bands could be seen whereas only one band was observed in PD-2 and P-1. Thus, the three strains could be grouped into three different zymodemes. These findings reveal the significant heterogeneity in G. lamblia isolates both from widely separated areas and within a single region. Heterogeneity among G. lamblia strains may explain the variable clinical manifestations, host response and treatment efficacy characteristic of human giardiasis.
Chaudhuri
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Department of Parasitology, National Institute of Cholera and Enteric Diseases, Calcutta, India.
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Bhattacharya
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Pal
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Das
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D000135:Acid Phosphatase / Q000032:analysis; D000469:Alkaline Phosphatase / Q000032:analysis; D000818:Animals; D004591:Electrophoresis, Polyacrylamide Gel; D005872:Giardia / Q000145:classification* / Q000201:enzymology; D005873:Giardiasis / Q000469:parasitology*; D005954:Glucosephosphate Dehydrogenase / Q000032:analysis; D006801:Humans; D007521:Isocitrate Dehydrogenase / Q000032:analysis; D007527:Isoenzymes / Q000032:analysis*; D008291:Malate Dehydrogenase / Q000032:analysis; D010733:Phosphoglucomutase / Q000032:analysis
D007527:Isoenzymes; D008291:Malate Dehydrogenase; D007521:Isocitrate Dehydrogenase; D005954:Glucosephosphate Dehydrogenase; D000469:Alkaline Phosphatase; D000135:Acid Phosphatase; D010733:Phosphoglucomutase