The in vitro growth response of Giardia trophozoites from the rabbit.

Abstract

SYNOPSIS. A visual technic has been developed for determining concentration of Giardia trophozoites in culture tubes. Such a technic is desirable because the nature of Giardia growth makes routine enumeration of these organisms by hemocytometer or electronic cell counter expensive in both time and material. The visual method of counting Giardia trophozoites was correlated with counts of the same suspensions of organisms using an electronic particle counter.As a part of the correlation, the growth response, as measured by electronic cell counter, was established for 8 primary axenic cultures of Giardia trophozoites from the rabbit. The average starting number of organisms was 3.7 ± 0.6 × 103 per ml, the average number of organisms at the peak of logarithmic growth was 1.78 ± 0.2 × 105 per ml, and the generation time was 18.1 ± 1.6 hr. These data are compared with the available literature data quantitating Giardia growth.