Culture Experiments on Intestinal Flagellates. I. Trichomonad and Other Flagellates Obtained from Man and Certain Rodents

Abstract

Survival in single tubes was prolonged by adding nutrients as needed, and water to compensate for evaporation. A modified Ringer''s was the basic fluid. Nutrients were mostly gastric mucin or Loeffler''s dried blood serum, commonly at 0.2%. Longest survival of 5 strains of Trichomonas hominis (4 from man, 1 from a dog) was 31, 36, 81, 81, 170 days; 2 strains from rats lived 185 and 187 days; all but the 1st 2 strains were arbitrarily discontinued. Trichomonas wenyoni (newn.) (T. parva Wenrich, not T. parva Alexeieff) was also present in cultures from rats. T. hominis-like forms have been found in Mus musculus, Peromyscus leucopus, Microtus pennsylvanicus and Fiber zibethica. Expts. are needed to determine physiological relationships. Since T. hominis and T. wenyoni from rats grew equally well in cultures, doubts arise as to the identity of the "T. parva" of rats reported as successfully cultivated by other authors. In cultures inoculated with caecal contents of a hamster (Cricetus auratus) containing flagellates resembling T. wenyoni, T. muris, T. minuta, Chilomastix bettencourti and Giardia muris of rats, only the first persisted, surviving in one tube for 438 days at room temp. When a culture was swallowed by the author, it was recovered in his feces, by culture, from the 2nd to the 6th day afterwards. A species of Monocercomonoides from a gopher (Thomomys bottae) survived 213 days at room temp. It was not recovered in the feces of the author who swallowed the contents of 4 culture tubes containing it. Of the caecal flagellates of guinea pigs, only Retortamonas caviae and Monocercomonoides hassali (?) persisted at room temp., both for 204 days. Species of Retortamonas and Monocercomonoides are widely distributed among both invertebrate and vertebrate hosts. Many are easily cultivated. The correlation between survival in cultures and wide distribution among hosts is regarded as significant.