eng Oriental Scientific Publishing Company Biosciences Biotechnology Research Asia 0973-1245 2017-03-25 14 1 83 87 10.13005/bbra/2420 20566 article Hussein O. M. Al-Dahmoshi 1 Ayad M. J. Almamoori 1 Noor S. K. Al-Khafaji 1 Department of Biology- College of science, University of Babylon, Iraq. Copper is a unique heavy metal with good antibacterial properties. It is functionality associated with various mechanisms, including damaging the microbial DNA, altering bacterial protein synthesis and altering membrane integrity. The resistance of E. coli to cooper add  another virulence trait that make it resistance to another heavy metals like silver and cadmium and resistance to many antibiotics which refluxed by same manner. Minimum inhibitory concertration (MIC) measurement were performed according to protocol of CLSI 2016. PCR were used to investigate presence of cusC gene using specify primer. The results of phenotypic investigation of copper resistance (tolerance) revealed that 16 (59.25%) of  UPEC isolated have MIC ˂= 500 ppm while the rest 11(40.75%) have MIC>=1500 ppm.   PCR results revealed that absence of cusC gene in  all UPEC isolated (16 (59.25%) that have MIC ˂= 500 ppm while it presence in all those have MIC>=1500 ppm (except U5 and U8). As a conclusion this study state that the CusCFBA efflux system is the main copper extruding that can protect E. coli from oxidative damage by cooper. https://www.biotech-asia.org/vol14no1/investigation-of-cuscfba-pump-among-uropathogenic-escherichia-coli-upec-isolated-from-women-with-cystitis-iraq-2/ UPEC; cooper/silver efflux; cusC; CusCFBA