A Limax-Amœba from the Rectum of the Grass Snake, Natrix natrix, as a Facultative Aerobe in vitro

Abstract

ALTHOUGH small amœbæ of the limax-type appear fairly commonly in cultures initiated from standing fæces or the intestinal contents of animals, in only a very few cases has the truly entozoic status of the amœba thus recovered been authenticated. The test hitherto has been the direct observation of the trophic amœbæ in host material, either in fresh preparations (for example, Vahlkampfia lacertae (Hartm.) from the large intestine of Lacerta muralis ¹ and an unnamed amœba seen by Mackinnon² in the intestine of a Tipulid larva) or in fixed and sectioned material (for example, V. discorbini Calv.³, parasitic in the Foraminiferan, Discorbis mediterranensis). Nevertheless, the frequent occurrence of limax-amœbæ as presumptive anaerobes, or, at least, facultative anaerobes, makes it tempting to suppose that some of them are also facultative parasites. Yet, so far, little experimental investigation of the status of limax-amœbæ has been reported. The following is a preliminary account of a strain, called Am, of limax-amœbæ isolated in this laboratory in June 1953.