PJS Vol 130 No. 2, December 2001  
Page 103-109  
ISSN 0031-7683  


Morphological and Physiological Characterization of Philippine Naegleria Isolates


Ian Kendrich C. Fontanilla*, Ronald H. Matias and Gloria L. Enriquez

Institute of Biology, College of Science
University of the Philippines, Diliman 1101, Quezon City, Philippines

Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.



Naegleria is a free-living amoeba with a transient flagellate stage and a resistant cyst in its life cycle. One species, Naegleria fowleri, causes primary amoebic meningoencephalitis (PAM) in humans. Eight environmental isolates of Naegleria were obtained from the University of the Philippines in Diliman, Mt. Arayat, Marikina, Taal Island, and Calamba, Laguna. They were subsequently maintained as clonal cultures derived from single cells. Together with the local clinical isolate that was previously designated as N. philippinensis (RITM-1) and a Japanese clinical isolate of N. fowleri (IT9611) for comparison purposes, all isolates were characterized using morphological and physiological parameters. Differences in cyst morphology, rate of encystment, rate of enflagellation, and thermal tolerance at 45ºC indicate that the Philippine isolates may actually belong to other species that have not yet been described.

Keywords: cyst morphology, encystment, enflagellation, thermal tolerance





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