The Noguchi-Adler phenomenon: an ultrastructural study of the effects of homologous antiserum on the growth of promastigotes of Leishmania braziliensis braziliensis and Leishmania hertigi hertigi.

A light and electron microscope study was made of the agglutinated bodies formed on growing promastigotes of a Leishmania b braziliensis and a L. h. hertigi strain in their homologous antisera to determine the role of leishmanial excreted factor (EF) in the Noguchi-Adler phenomenon, since the L. b. braziliensis strain produced a demonstrable EF, whereas the L. h. hertigi strain did not. Promastigotes of L. b. braziliensis, when grown in high concentrations of homologous antiserum, formed Noguchi-Adler (N-A) bodies, in which the cells were embedded in an extensive amorphous matrix. The cells of L. b. braziliensis in the embedding matrix often appeared unhealthy or dead, with swollen flagellar pockets and distorted flagella, with which small visicles were associated. Even though promastigotes of L. h. hertigi do not produce an EF that precipitates with homologous antibody, N-A bodies containing agglutinated cells separated by a thin structured layer of precipitate were formed during growth in homologous antiserum. In high concentrations of antiserum, some of the agglutinated cells of L. h. hertigi were enlarged and showed syncytial characters that included up to five nuclei, two dividing nuclei and five basal bodies associated with a single kinetoplast. Small vesicles and membranous folds were also observed between cells. The complexity of the Noguchi-Adler phenomenon and significance of the morphological changes seen are discussed.