Groundwater in Egypt is of a vital importance and the contamination of drinking groundwater wells is a common problem in many rural areas. Forty-three different sites were selected from eight rural Governorates (Qena, Sohag, Kalubiya, Menofiya, Sharqiya, Gharbiya, Kafr El-Sheikh and Daqahliya) to carry out this study. Study of the effect of heavy metals; aluminum (Al), manganese (Mn), chromium (Cr), arsenic (As), cadmium (Cd) and lead (Pb) on the growth of fungi and bacteria indicated that fungi were strongly resistant to heavy metals and could survive high metal concentrations than bacteria. Penicillium spp. showed resistance to all tested heavy metals except Cd, while Aspergillus spp. and Geotrichum sp. showed resistance to all. On the other hand, most bacterial isolates were sensitive to Cd, Cr, Pb and As and showed some resistance to Al. Furthermore, Pseudomonas aeruginosa, Bacillus licheniforms, Kurthia gipsonii, and Escherichia coli were the most resistant isolates. Results showed that 96% of bacterial isolates were resistant to one or more of the tested antibiotics. None of the tested isolates showed resistance to ofloxacin. Also, about 58% of the total resistant isolates showed multiple antibiotic resistance (MAR), and Pseudomonas aeruginosa was the most resistant species. On the other hand, the calculated antibiotic resistance index (ARI) for the bacterial isolates collected from the groundwater at Gharbiya did not exceed the high risk level while that of Kafr El-Sheikh, Sohag, Kalubiya, Daqahliya, Menofiya and Qena considered as water of high risk pollution. Some interactions between fungal and bacterial communities were also studied. Results indicated that Chlorination of groundwater affected the count of total coliform and fecal coliform bacteria and about 70% and 90% of fungal and bacterial counts, respectively, were removed. The water quality index (WQI) for the selected areas was also studied. Finally, we recommended that the groundwater quality status of the rural areas must be studied carefully and the mycobiota of water should be considered when the microbiological safety and quality of drinking water are assessed.
Key words: Groundwater, fungi, bacteria, contamination, antibiotic, resistance, water quality
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