in vitro culture and isoenzyme analysis of giardia lamblia

unique about Giardia in humans, which seemed, on evidence present then, not to
be the case. They therefore advocate use of the specific name "duodenalis" for
taxonomic correctness.
On the other hand, some authorities argue against use of the term G. duodenalis
to designate a species. Their argument is based on the fact that application of
biochemical and nucleic acid techniques has revealed marked genetic diversity
among Giardia isolates that belong to the duodenalis group (morphologically
indistinguishable). For example, a report by Erlandsen et al. (1990) indicated that
a variety of Giardia species possess claw hammer shaped median bodies (thus
belonging to the duodenalis group). However, comparative molecular typing
studies such as karyotype analysis, rDNA restriction enzyme pattern (Mahbubani
et al., 1992) and rRNA gene base pair sequencing (Weiss et al., 1992) show
marked distinction between G.lamblia, G.ardae and G.muri$ (Iamblia and ardae
expectedly belong to the same species (duodenalis) and are therefore presumably
similar). Therefore, according to Erlandsen (1994), Filice's description of the two
specific morphologic groups, G.muris (pair of small rounded median bodies) and
G.agi/is (club-shaped median body) appear to be acceptable. However use of
G.duodenalis (claw hammer shaped median body) to designatei:i species is
controversial. For these reasons, Erlandsen (1994) suggested that the term
G.duodenalis should in future be restricted to the description of the morphological
type of median body within trophozoites and it should not be used as a species
designation because as such it is a misnomer. He argues that although some
investigators indicate that G.duodenalis is synonymous with G.lamblia or
G.intestinalis, and that this species can infect humans, birds and reptiles, such
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