Urinary tract infection (UTI) is the second most common bacterial infection and important public health problem of human among all age groups from neonate to geriatric. Uropathogenic Escherichia coli (UPEC) accounts for approximately 85% of community acquired UTIs and 50% of hospital acquired UTIs. The current study aimed to investigate dominant CTX-M genotypes among local UPEC isolated from patients with cystitis. Phenotypic detection of Cefotaxime-Resistant Uropathogenic Escherichia coli (CRUPEC) were performed by Kirby-Bauer disk diffusion method (CLSI 2016). The DNA were extracted and investigation of four resistance genes blaCTX-M  by a multiplex PCR assay using specific primer pairs. The results of phylogenetic subgrouping of UPEC using multiplex PCR to detect chuA (279bp), yjaA (211bp) and TspE4.C2 (152bp) revealed that among 56 CRUPEC 47(83.93%) were ExPEC (37(66.07%) for B2₃, 6(10.72%) for B2₂, 3(5.36%) for D1 and  1(1.78%) for D2). InPEC compile 9(16.07%). Genotypic investigation of cefotaxime resistance among 56 CRUPEC were performed using specific four primer pairs to detect the genotypes of blaCTX-M clusters (I, II, III and IV). Among 65 CRUPEC,  36 (64.28%) were positive for for blaCTX-MI, 38(67.85%)  for blaCTX-MII 26(46.43%) for blaCTX-MIII and 18(32.14%) for blaCTX-MIV (Figure 9). Concern possessing of isolates for more than one blaCTX-M genotypes were also reported in this study.  Our results revealed that blaCTX-M  were present in 50 (89.29%) of CRUPEC. Co-existence of more than on genotypes were reported in 38(67.86%). The results displayed that  40(80%) of blaCTX-M positive CRUPEC were belong to group B2, 4(8%) for group D, 3(6%) for group A and 3(6%) for group B1. The current study conclude the presence of blaCTX-M clusters (I, II, III, IV) as a main mechanisim or cefotaxime resistance among CRUPEC and coexistance of multible cluters within same isolates that may leads to emergence of new hybrides of blaCTX-M.