en <span style="line-height:normal"><span style="text-autospace:none"><span style="unicode-bidi:embed"><b><span style="font-size:10.0pt"><span style="background:white"><span cambria="" style="font-family:"><span style="color:#e36c0a">Aims:</span></span></span></span></b><b> </b><span style="font-size:10.0pt"><span style="background:white"><span cambria="" style="font-family:">Urinary tract infection is the most common adult bacterial infection worldwide. Antigens of ABO and Lewis blood groups may influence bacterial adherence and lead to an increase in the frequency of urinary tract infections in adults. This study aimed to evaluate the relationship of ABO and Lewis blood groups with urinary tract infections. </span></span></span><span style="font-size:10.0pt"><span style="font-family:"Cambria",serif"></span></span></span></span></span><br> <span style="line-height:normal"><span style="unicode-bidi:embed"><b><span style="font-size:10.0pt"><span style="background:white"><span cambria="" style="font-family:"><span style="color:#e36c0a">Materials & Methods: </span></span></span></span></b><span style="font-size:10.0pt"><span style="background:white"><span cambria="" style="font-family:">In this experimental study, a blood sample of 80 urinary tract infection patients from </span></span></span><span style="font-size:10.0pt"><span style="background:white"><span cambria="" style="font-family:">AL-Sader Teaching Hospital</span></span></span><span style="font-size:10.0pt"><span style="background:white"><span cambria="" style="font-family:">, Iraq, and 50 healthy persons was used for the determination of ABO and Lewis blood groups by agglutination assay. Urine samples of urinary tract infection patients were cultured and identified based on culture characteristics, gram staining, and biochemical tests.</span></span></span></span></span><br> <span style="line-height:normal"><span style="unicode-bidi:embed"><b><span style="font-size:10.0pt"><span style="background:white"><span cambria="" style="font-family:"><span style="color:#e36c0a">Findings:</span></span></span></span></b><b> </b><span style="font-size:10.0pt"><span style="background:white"><span cambria="" style="font-family:">Urinary tract infection was significantly higher in patients with the O blood group (42.5%) and the Lewis (a-b-) phenotype (38.8%) than in patients with other blood groups and the control group. <i>Escherichia coli</i> was the most common bacterial isolate observed in urinary tract infection patients. Also, <i>E. coli</i> was significantly higher in the UTI patients with the O blood group and the Lewis (a-b-) phenotype.</span></span></span></span></span><br> <span style="line-height:normal"><span style="unicode-bidi:embed"><b><span style="font-size:10.0pt"><span style="background:white"><span cambria="" style="font-family:"><span style="color:#e36c0a">Conclusion: </span></span></span></span></b><span style="font-size:10.0pt"><span style="background:white"><span cambria="" style="font-family:">People of the O blood group and the Lewis (a-b-) phenotype are more susceptible to urinary tract infections. <i>Escherichia coli</i> is the main cause of urinary tract infections. </span></span></span></span></span><br> &nbsp; Urinary Tract Infection,Escherichia coli,ABO Blood Group,Lewis Blood Group,Secretor Status, 43 48 http://ijwph.ir/browse.php?a_code=A-10-2038-3&slc_lang=en&sid=3 Q.K. Baqir 1003194753284600379264 1003194753284600379264 No Department of Surgery, College of Medicine, University of Basrah, Basrah, Iraq G.K. Baqer 1003194753284600379265 1003194753284600379265 No Department of Human Anatomy, College of Medicine, University of Basrah, Basrah, Iraq F.K. Baqer 1003194753284600379263 1003194753284600379263 No Department of Surgery, AL-Sader Teaching Hospital, Basrah, Iraq B.A. Abbas 1003194753284600379161 1003194753284600379161 Yes Department of Microbiology, College of Veterinary Medicine, University of Basrah, Basrah, Iraq