A method of decontaminating Strongyloides venezuelensis larvae for the study of strongyloidiasis in germ-free and conventional mice

To study the possible influence of intestinal micro-organisms on the course of strongyloidiasis in mice, a method was developed to obtain axenic infec tive larvae of Strongyloides venezuelensis, Cultured larvae from convention al mice were treated with sodium hypochlorite 0.25% for 10 min, washed in d istilled water and then exposed to various combinations of antibiotics for 30 or 60 min, Success was achieved with a combination of penicillin 180 mg/ L and ceftazidime 1 mg/ml, Decontamination of the larvae was determined by aerobic and anaerobic culture and by inoculation into gnotobiotic mice, Via bility was established by subcutaneous inoculation of larvae into germ-free and conventional mice, Preliminary results showed that gnotobiotic mice we re more susceptible than conventional mice to infection with axenic S, vene zuelensis larvae as judged by faecal egg excretion, recovery of worms in th e small intestine and histopathological examination of the duodenal mucosa, These results suggest that the normal intestinal flora protects the host a gainst experimental infection with S, venezuelensis.