In the last decade, with the advancement of genetic research, there is more and more confirmation of hereditary as a cause of susceptibility to urinary tract infections.
Generally speaking, epithelial cells are thought to lack the fortitude to stay together more so in women; this is believed to be due in part to biological and various other factors. (In no way is this to be considered an expert opinion)
Another possible explanation for this is the number and type of receptors epithelial cells to which bacteria are attached to are thought to be controlled by hereditary means.
Many of these receptors are red blood cell antigens; which are expressed in the the epithelial lining of the urinary tract. .
For example, the erythrocyte antigen P serves as the receptor for P-fimbria of Escherichia coli. The risk of pyelonephritis is much lower in people who do not produce this antigen.
People whose erythrocyte antigen A and erythrocyte antigen B are not secreted by exocrine glands are much more susceptible to reoccurring urinary tract infections. Genetics is a suspected cause for the difference in the composition of glycolipid epithelium found in the urinary tract