in vitro culture and isoenzyme analysis of giardia lamblia

guinea-pig intestine; laboratory rats were infected by cysts isolated from human
faeces and cysts from man as well as those from the rat infected a domestic fowl.
He subsequently characterised constant morphological features such as cell
dimensions as well as the number and shape of median bodies, as specific
characteristics in addition to host occurrence. He recognised three morphologic
species, G.agilis, (club-shaped median body) which is infective to amphibians,
G.muris (two small rounded median bodies) from rodents and G.duodenalis (claw
hammer shaped median body) from mammals. G.duodenalis has a wide host
range.
In the ensuing years the taxonomic classification of Giardia remained in a state of
flux as it does today. Lack of agreement regarding the correct specific name for
the mammalian isolates, in particular the Giardia of human origin, greatly
contributes to the taxonomic confusion. The names G.lamblia and G.intestinalis
have been widely used to describe the human isolates. However, Thompson et al.
(1990), stated that the soundly structured, reproducible and logical morphometrics
scheme proposed by Filice (1952) had found widespread favour and was
advocated by many leading authorities in the field. They stated that according to
the Rules of Zoological Nomenclature, duodenalis has priority over intestinalis as a
specific name for the vertebrate isolates since there is no justification for using the
name intestinalis. Other authorities also express the view that the specific name
"duodena/is" is correct for isolates of human origin; other names ("intestinalis" and
"/amb/ia') are incorrect on taxonomic grounds. For example, Meyer (1985)
concluded of other names for the "duodenalis" group (i.e. G.intestinalis or
G.lamb/ia), that their use for Giardia in humans suggests that there is something
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