Effects of Pluronic F-68 on larval development of the hookworm,Necator americanus

Summary Eggs of the nematode,Necator americanus, were incubated at 28°C for up to 120h in medium (prepared from mouse faeces) supplemented with 0.4% (w/v) or 5% of either commercial grade or a silica-Amberlite purified fraction of the non-ionic surfactant, Pluronic F-68. Exposure to commercial grade or purified Pluronic at both concentrations delayed egg hatching. However, subsequent larval growth, as assessed by length of larva, buccal capsule, oesophagus and tail, was significantly (P<0.05) increased (maximally following exposure to 5.0% of the purified fraction). No further development occurred in larvae exposed to other Pluronic fractions tested after 48h, irrespective of concentration. These results suggest that Pluronic may be a valuable supplement in media used for the axenic culture of nematode larvae.