Free amino acid analyses of 4 strains of Entamoeba histolytica and of E. invadens in the CLG medium.

Abstract

SYNOPSIS. The free amino acids of E. invadens and 4 strains of E. histolytica cultured in the CLG medium have been identified by thin layer chromatography. The chromatogram patterns of 3 strains grown for 72 hr at 37°C (103, K‐9 and 200) were nearly identical. Amino acids detected on chromatograms according to Rf values, relative positions on chromatogram plates, and identifying colors using a polychromatic ninhydrin spray were: leucine/isoleucine, tyrosine, valine, alanine, glycine, glutamic acid, lysine/ornithine, histidine, proline, plus very small amounts of arginine and possibly serine, aspartic acid and citrulline/glutamine. Cysteic acid may also be present. The same amino acids were detected on chromatograms using comparable extracts of strain Laredo and E. invadens grown for 6 days at room temperature. However, the patterns were different in that serine, glycine, threonine and especially alanine were present in greater abundance in these latter 2 cell types.These chromatogram patterns were compared with similar analyses of strains Laredo and 200 grown in the modified Shaffer‐Frye medium of Reeves.Similar analyses are reported on the basic ingredients of the CLG medium, including the cells and protoplasts of the Bacteroides, the non‐multiplying bacterial associate employed in the CLG medium. The chromatogram patterns of the Bacteroides, protoplasts and medium were decidedly different from those of the amebae, thus indicating that adequate separation of bacteria, amebae and medium was accomplished.Analyses of the culture filtrates of all cells analyzed revealed a possible difference between the Laredo strain and the other strains of E. histolytica (103, K‐9 and 200) in amino acid utilization. Similar differences were observed between the Laredo strain and E. invadens.