Related Experiment Videos
Isoenzyme variation within the genus Cryptosporidium
B W Ogunkolade1, H A Robinson, V McDonald
1Department of Clinical Sciences, London School of Hygiene and Tropical Medicine, UK.
Abstract:
Soluble extracts of the oocysts of Cryptosporidium parvum had demonstrable, but low, activities of malate dehydrogenase (MDH, EC. 1.1.1.37), carboxylesterase (ES, EC 3.1.1.1) and lactate dehydrogenase (LDH, EC. 1.1.1.27) following thin-layer starch-gel electrophoresis. Much higher activities of glucose phosphate isomerase (GPI, EC. 5.3.1.9) and phosphoglucomutase (PGM, EC. 2.7.5.1) were found, and zymograms of these two enzymes were used to characterise isolates of C. parvum from human, bovine, ovine and cervine sources, C. muris from the brown rat and C. baileyi from young turkeys. PGM and GPI zymograms clearly distinguished between C. parvum, C. muris and C. baileyi. The five isolates of C. parvum showed the same electrophoretic mobility for GPI, whereas the PGM mobility of the single human isolate of C. parvum examined was clearly different from that of the other isolates. This is the first report of the use of isoenzymes to distinguish between species and isolates of Cryptosporidium.
Insights
Isoenzyme analysis using glucose phosphate isomerase (GPI) and phosphoglucomutase (PGM) successfully differentiated Cryptosporidium species and isolates. This method distinguished C. parvum, C. muris, and C. baileyi, with unique PGM profiles observed in a human C. parvum isolate.
Area of Science:
- Parasitology
- Biochemistry
- Molecular Biology
Background:
- Cryptosporidium is an important protozoan parasite causing gastrointestinal illness in various hosts.
- Accurate identification and differentiation of Cryptosporidium species and isolates are crucial for epidemiological studies and control strategies.
- Existing methods for Cryptosporidium characterization can be labor-intensive or lack discriminatory power.
Purpose of the Study:
- To investigate the potential of isoenzyme analysis for differentiating Cryptosporidium species and isolates.
- To characterize the enzyme profiles of Cryptosporidium isolates from different host sources.
- To establish a reliable method for distinguishing between Cryptosporidium species and strains.
Main Methods:
- Soluble oocyst extracts were subjected to thin-layer starch-gel electrophoresis.
- Enzyme activities of malate dehydrogenase (MDH), carboxylesterase (ES), and lactate dehydrogenase (LDH) were assessed.
- Higher activities of glucose phosphate isomerase (GPI) and phosphoglucomutase (PGM) were analyzed using zymograms.
- Isolates from human, bovine, ovine, cervine, rat (C. muris), and turkey (C. baileyi) sources were examined.
Main Results:
- Low activities of MDH, ES, and LDH were detected.
- High activities of GPI and PGM were observed, suitable for zymogram analysis.
- GPI and PGM zymograms clearly distinguished between C. parvum, C. muris, and C. baileyi.
- All five C. parvum isolates exhibited identical GPI electrophoretic mobility.
- A distinct PGM electrophoretic mobility was identified in the human C. parvum isolate compared to other C. parvum isolates.
Conclusions:
- Isoenzyme analysis of GPI and PGM provides a robust method for differentiating Cryptosporidium species.
- This technique can also distinguish between different isolates of the same species, particularly C. parvum.
- The observed variations in PGM profiles suggest potential genetic diversity within C. parvum isolates.
- This study presents the first report utilizing isoenzymes for Cryptosporidium species and isolate differentiation.