Chemical and Microbial Analysis of Water Resources in United Arab Emirates

Acanthamoeba (AC) is a microscopic, free-living amoeba found worldwide in the environment. It can infect the eyes through contact lens use, cuts, skin wounds, or inhaling into the lungs. Three diseases caused by (AC) are Acanthamoeba keratitis: which is an infection of the eye cornea, Granulomatous Amoebic Encephalitis (GAE): which is a severe infection of the brain and spinal cord; and Disseminated infection: which is an infection of the skin, sinuses, lungs, and other organs independently or in combination. When exposed to unfavourable conditions, Acanthamoeba develops into a dormant cyst that can resist temperature extremes (-20 to 56°C). In their trophozoite form, Acanthamoeba can survive and multiply at a pH range from 4 to 12. With these unique characteristics, AC can provide the bacteria with a safe haven from environmental harsh conditions in addition to becoming a renewable source of bacterial contamination. This study is the first to investigate the existence of AC in the United Arab Emirates (UAE). Therefore, this study aims at isolating AC from UAE water samples, identifying AC species by molecular methods, and investigating the mode of association with bacterial communities. Fifty-seven samples from 4 emirates were filtered through nitrocellulose membrane, which was placed afterwards on non-nutrient agar (NNA) supplemented with heat-killed Escherichia coli (E.coli), incubated for two weeks, and examined under a converted microscope. Most of the plates were found to contain Acanthamoeba trophozoite and or cysts. Acanthamoeba was grown axenically in Peptone Yeast Glucose (PYG) medium and identified by 18s rDNA PCR as Acanthamoeba spp. Testing samples for microbial contents found that Emirate-3 (130 species) was the highest in bacterial species contents, followed by Emirate -4 (121 species), and finally, Emirate-1(91 species) had the least in bacteria species numbers. It is well known that AC feeds on some bacterial species and hides others from harsh environments. To investigate the interaction activity of AC with the bacterial spp isolated from UAE water samples, the toxicity of a group of bacteria, isolated from different water sources on Human KB Epithelial Cells was assessed. Survivability studies of Acanthamoeba cysts were assessed by various levels of chlorination exposure. Results indicated that chlorination at a concentration of 5ppm and exposure for 30 minutes achieved about 72% efficiency of AC disinfection; however, as chlorination levels increase, the disinfectant effect becomes more obvious. At 6 ppm, 91.7% of AC were killed, while at concentrations above 12 ppm, all AC were dead. A quick methodology for identifying AC directly from nitrocellulose membrane was developed, which would consume a short time (two hours) to isolate AC without having to wait for weeks to grow AC on nutrient cultures.