Is Acanthamoeba sp. normally found in the eyes? A study was carried out to establish the possibility of Acanthamoeba sp. as a part of the normal conjunctival flora. Conjunctiva swabbing were carried out in 286 healthy Orang Asli school children using sterile cotton swab. The swab was then inoculated onto non-nutrient agar (NN-A). Heat killed Escherichia coli that was used as food source for the growth of the amoebae was pipetted onto and away from the smear. The plates were incubated at 30 degrees C and examined daily using an inverted microscope for 14 days. Morphology of the trophozoites and cysts of the amoebae were used as the taxonomic criteria for identification. Positive-controls and negative-controls were done to check for the consistency of the technique used and monitoring of contamination respectively. None of the conjunctiva swab cultured was positive for Acanthamoeba sp. This finding may indicate that Acanthamoeba sp. is not part of normal conjunctival flora or conjunctiva swab is an insensitive technique to isolate the organism. However, a more extensive research is needed to investigate these possibilities.
Acanthamoeba spp. and Balamuthia mandrillaris are causative agents of granulomatous amoebic encephalitis (GAE), while Naegleria fowleri causes primary amoebic meningoencephalitis (PAM). PAM is an acute infection that lasts a few days, while GAE is a chronic to subacute infection that can last up to several months. Here, we present a literature review of 86 case reports from 1968 to 2016, in order to explore the affinity of these amoebae for particular sites of the brain, diagnostic modalities, treatment options, and disease outcomes in a comparative manner.