Active and concrete evidences about sexual reproduction and life cycle in the parasitic generation of Strongyloides stercoralis in human host
International Journal of Development Research
Active and concrete evidences about sexual reproduction and life cycle in the parasitic generation of Strongyloides stercoralis in human host
Received 22nd April, 2018; Received in revised form 09th May, 2018; Accepted 06th June, 2018; Published online 30th July, 2018
Copyright © 2018, Feleke Eriso. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Background: Strongyloides stercoralis was believed to have two kinds of life cycle. One of them was an internal parthenogenetic life cycle that constituted the parasitic generation. Some authors also stated that this parasitic generation of the internal life cycle used to reproduce only by protandrogony (i.e., hermaphroditism). The second type of life cycle was the external sexual cycle, interacting among free-living worms that represented the free-living generation in soil. The key objectives of this study were to: • verify the type of reproduction in the parasitic generation of S. stercoralis, and • establish a complete integrated life cycles of both parasitic and free-living generations of S. stercoralis. Method: The major sites of stool sample collection were selected to be the elementary schools (from students) at Dilla District, because S. stercoralis was ascertained to be endemic in this region. The parasitic worms of Strongyloides stercoralis obtained from fresh stools were used to set growth culture of free-living generation of this very species and to find the free-living male & female in copulation from the growth culture. A set of parasitic male & female in copulation isolated from a fresh stool sample of a patient under medical care in a hospital was also included. Result: The male & female worms of S. stercoralis had been isolated from both parasitic & free-living generations while they were in the actual copulation. Several males & females of S. stercoralis were also isolated from fresh stool samples of student children examined. Conclusion: The method of reproduction in the parasitic generation of S. stercoralis in human host was practically proved to be certainly sexual. This verified conclusion was the first practical achievement in the entire globe by solving the persistent problems (i.e., erroneous concepts of parthenogenesis and protandrogony as the types of reproduction in the parasitic generation of S. stercoralis) that had been misleading and puzzling the minds of the concerned scientists of the world until the establishment of this very achievement. Additionally, this achievement had enabled the investigator to construct the complete integrated life cycles of both parasitic and free-living generations of S. stercoralis.