Giardia lamblia: Evaluation of roller bottle cultivation

A modified “outside-in” roller bottle with a high ratio of surface area to volume was used to cultivate Giardia lamblia. Yields were high, more so when bottles were rotated at 6 rph (9.3 ± 4.0 × 10⁸ trophozoites/bottle) than at 12 rph (4.2 ± 1.9 × 10⁸ trophozoites/bottle). The method was more efficient than stationary tube culture with respect to utilization of culture medium; trophozoite concentration after roller bottle culture (1.7 ± 0.8 × 10⁶ trophozoites/ml) was significantly higher (by a factor of 2.8) than concentrations obtained from stationary tube culture (0.6 ± 0.4 × 10⁶ trophozoites/ml, P < 0.002). Increased yields from roller bottle culture were not accounted for by a reduction in mean trophozoite generation time (roller culture, 10.7 ± 1.2 hr; stationary tube culture, 10.3 ± 0.6 hr) but may be related to prolongation of the period of log phase growth or increased trophozoite survival. Trophozoite yields expressed per unit surface area were significantly higher from roller bottle culture (7.2 ± 3.1 × 10⁵ trophozoites/cm²) than from stationary tubes (1.9 ± 1.0 × 10⁵ trophozoites/cm², P < 0.002). Attempts to cultivate G. lamblia in spin culture using polystyrene beads (Biosilon) as a microcarrier were unsuccessful, trophozoite growth being inhibited rather than promoted. Roller bottle culture of G. lamblia, however, is efficient, economical, and less laborious than stationary tube culture, particularly when more than 10⁸ trophozoites are required.