Isolation, Morphotyping, Molecular Characterization and Prevalence of Free-Living Amoebae from Different Water sources in Makkah city, Saudi Arabia

Free-living amoebae (FLA) are protozoa that can be found in a wide range of habitats around the world. Some species have been found to be pathogenic to humans in addition to their normal distribution. There is no research on the prevalence of FLA in various water sources in Makkah city that we are aware of. The aim of this study was to investigate the prevalence of FLA from various water sources in a different part of the city. A total of 86 water samples were processed and cultured with Escherichia coli overlay on non-nutrient agar medium (NNA). Microscopic examination was used to examine the samples. Fifty (58.1%) of the 86 samples tested were positive for FLA. Amoebae identified by morphology belonging to the genus Acanthamoeba were 30 (34.9%) and that belonging to the genus Naegleria, were 20 (23.3%). Among the positive cases, 100% of ponds, 80% of air conditioner exhaust, 50% of water fountains and tape water filters, 40% of swimming pools and 33.3% of stored tanks. The absence of FLA in the examined wells was a striking feature. Polymerase chain reaction (PCR) on DNA showed a 229-bps fragment using Nelson primers and a 500-bps fragment using Acanthamoeba genus-specific primer pair JDP1/JDP2. In conclusion, Acanthamoeba spp. was the most predominant type of free-living amoeba and more prevalent in ponds water absent in wells as shown by culture, microscopy and PCR.