in vitro culture and isoenzyme analysis of giardia lamblia

CHAPTER 7
APPLICATION OF ISOENZYME ELECTROPHORESIS TO GIARDIA L YSATES
7.1 INTRODUCTION
Isoenzyme electrophoresis is a technique whereby separation of the multiple
forms of a given enzyme in a single organism I individual, or in different members
of the species, is achieved by electrophoresis. The characteristic banding patterns
of enzymes then allow grouping into zymodemes (strains determined by
isoenzyme patterns). Isoenzyme (and DNA) analyses have been proven to be
excellent tools in determining the extent of inter- and intra-specific variation in
protozoan, helminth and arthropod parasites (Heinz-1988). Isoenzyme
electrophoresis distinguishes the distinct forms of enzymes that are genetically (or
post-translationally) determined. Thus an isoenzyme profile is a direct reflection of
the genetic make up of an organism.
The technique of isoenzyme electrophoresis has been successfully employed in
characterisation of zymodemes of pathogenic and non-pathogenic strains of
Entamoeba histolytica (Jackson et al., 1982; Sargeaunt et al., 1982; Matthews et
aI, 1983). The technique has also been applied in an attempt to characterise
strains of Giardia duodenalis, to address different aspects of giardiasis such as:
• Epidemiological distribution
Meloni, et al. (1988) compared thirty isolates from humans and felines by
isoenzyme electrophoresis using ten of 25 enzyme systems that were
assayed. They identified 13 different zymodemes, which could be grouped
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