Isolation of Bacteria from River Water and Drinking Water: A Comparative Study in Nasiriyah City

This study aimed to isolate and identify bacteria present in river water and drinking water sources in Nasiriyah city, Dhi Qar province. A total of 100 water samples were collected from four different sources (25 samples each): the Euphrates River (representing natural river water), tap water, bottled water, and reverse osmosis (RO) water (representing different drinking water sources). Laboratory examinations were conducted using traditional bacterial culture techniques and biochemical tests. Results showed the presence of various bacterial species in all studied water sources. The Euphrates River recorded the highest bacterial contamination level with an average of 800–5,200 CFU/ml, and RO water showed the lowest contamination level with