Uropathogenic Escherichia coli (UPEC) are a common cause of urinary tract infections (UTIs) in humans. While the importance of natural killer (NK) cells in innate immune protection against tumors and viral infections is well documented, their role in defense against bacterial infections is still emerging, and their involvement in UPEC-mediated UTI is practically unknown. Using a systematic mutagenesis approach, we found that UPEC adheres to NK cells primarily via its type I fimbriae and employs its hemolysinA toxin to kill NK cells. In the absence of hemolysinA, NK cells directly respond to the bacteria and secrete the cytokine TNF-α, which results in decreased bacterial numbers in vitro and reduction of bacterial burden in the infected bladders. Thus, NK cells control UPEC via TNF-α production, which UPEC counteracts by hemolysinA-mediated killing of NK cells, representing a previously unrecognized host defense and microbial counterattack mechanism in the context of UTI.
Several studies suggest decreased fertility potential in patients with a history of testicular torsion. However, in the current study in couples in which the male had a history of testicular torsion the pregnancy rate and the interval to pregnancy were within the accepted range of the general population.
Patients with a NVF pose a surgical challenge. Successful fistula repair does not necessarily result in adequate continence due to an incompetent outlet. NVF location at the UNA is the more common location and is more challenging in regard to successful resolution of the NVF as well as possible urinary incontinence post-NVF repair.
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