In present study 74 specimens of urine were collected from patients suffering from urinary tract infections.Fifty (67.56%) isolates were identified as Escherichia coli. 78% of isolates were identified as extendedspectrum beta lactamases (ESBL) producer. Antibiotic susceptibility t est was done and ceftazidime wasselected to complete this study by implying stress at sub-MIC on isolate harbor high number of resistancegenes (N11) and compared with sensitive isolate (S). Only four β-lactamase coding genes were detected;blaTEM, blaPER, blaVIM and blaCTX-M-2 and N11 had blaTEM, blaPER, and blaVIM. It was found that the resistantisolate did not form biofilm when compared with the sensitive one, which formed moderate biofilm. Inaddition, ceftazidime stress reduced the ability to produce slime layer and affected the viable bacterial countin combination with pH and temperature stresses. (PDF) Effectiveness of some β-lactamase encoding genes on biofilm formation and slime layer production by uropathogenic Escherichia coli. Available from: https://www.researchgate.net/publication/326088490_Effectiveness_of_some_b-lactamase_encoding_genes_on_biofilm_formation_and_slime_layer_production_by_uropathogenic_Escherichia_coli [accessed Jan 18 2025].