Proteinases in Naegleria Fowleri (strain NF3), a pathogenic amoeba: a preliminary study

Naegleria fowleri is a free-living amoeba, known as a causative agent for a fatal disease of the central nervous system (CNS) in man such as Primary amoebic meningoencephalitis (PAM). Factors contributing to its pathogenicity and its distribution in the environment have been investigated by previous researchers. In case of its pathogenicity, several enzymes such as phospolipase A and sphingomyelinase, have been proposed to probably act as aggressors in promoting PAM but no study so far have been conducted to investigate the presence of proteinase enzyme in this amoeba although a 56kDa cystein proteinase enzyme has been identified in Entamoeba histolytica as an important contributing factor in the amoeba's virulence. In this preliminary study, a pathogenic amoeba, Naegleria fowleri (strain NF3) was examined for the presence of proteinases. Samples of enzymes in this amoeba were analysed by electrophoresis using SDS-PAGE-gelatin gels. The results showed that this amoeba possesses at least two high molecular weight proteinases on gelatin gels; their apparent molecular weights are approximately 128 kDa and approximately 170 kDa. Band of approximately 128 kDa enzyme is membrane-associated and its activity is higher at alkaline pH compared with lower pH; at lower pH, its activity is greatly stimulated by DTT. The approximately 170 kDa band enzyme appears to be inactivated at pH 8.0, at lower ph its activity is higher and DTT-dependance. The activity of this enzyme is partially inhibited by inhibitor E-64 but markedly inhibited to antipain suggesting it belongs to the cysteine proteinase group.

Detection of Hartmannella sp, a free-living amoeba from Sungai Setiu, Terengganu

Hartmannella sp is one of the free-living amoebae that have the ability to infect animal tissues because it has been found in human's nasal mucosa, dog's bronchial and turkey's intestine. Treatment for diseases inflicted by free-living amoebae is difficult because most of them infect and damage the host's tissues, so preventive measures are better to take rather than to cure the diseases. In this study, water taken from several stations namely Kampung Padang, Kampung Besut, Ibu Bekalan Setiu, Kampung Tasik, Kampung Guntung, Kampung Nyatoh, Kampung Penarik and Kampung Mangkok) along Sungai Setiu, Terengganu was examined for the presence of Hartmannella sp. The results of this study indicated that only Ibu Bekalan Setiu station was found positive to have the amoeba. Detail results on the water quality and nutrient contents measured in relation to the distribution of the amoeba at Ibu Bekalan Setiu station are presented and discussed.