I visited a doctor who suggested that it is possible for UTI causing bacteria (E coli among others) to climb-up (so to speak) the urine stream, from a dirty urinal for example.

I would like to ascertain if this is possible. To me it is just unbelievable.

  • I find it equally unbelievable. Even if bacteria could defy gravity and the force of flowing water, they would immediately encounter the urethra, which is a very inhospitable environment for pathogens due to the body's defenses. This is why females suffer more urinary tract infections than males -- men's urethras are longer so present a more formidable barrier.
    – Carey Gregory
    Commented Jul 25, 2016 at 18:18

1 Answer 1


Credit to: No Such Thing As A Fish Podcast.

On one of the latest podcasts Harkin descries that with the Mate Tea (a very fine particulate tea) you can get upstream movement of particulates. "The tea leaves climb back into the kettle"

This references: http://arxiv.org/abs/1105.2585 S. Bianchini, A. Lage-castellanos, E. Altshuler (Submitted on 12 May 2011)

The phenomenon was first observed during the preparation of the typical Argentinian drink, mate, when hot water was poured, from a pot, on a water surface “contaminated” with floating mate particles (each particle is like a grass leave of an average area near 0.5mm^2 If the column of falling water was short enough (say, under 1cm-height), particles of mate were observed to “swim up the stream”, actually reaching the originally “uncontaminated” water pot.

The study continues:

For distances of the order of 1 cm or less, some of the floating particles eventually start to “climb up the stream”

Unless you were peeing 1cm away from the urinal, it's not possible for it to climb your pee stream.

(Your doctor might have been referring to "witches kiss" where your todger touched the ceramic of the bowl while sitting down)

  • 1
    Witch's kiss... now there's a new one.
    – Carey Gregory
    Commented Jul 25, 2016 at 15:25
  • If my doctor was talking about the "withces kiss", this question would not exist.
    – shrm
    Commented Jul 25, 2016 at 18:08
  • 1
    Interesting article there, though I am not sure if the size of bacteria is "big enough" to experience the forces describe in the article linked. I assume Mate leaf particles or even chalk dust particles are much bigger than a typical bacteria in size.
    – shrm
    Commented Jul 25, 2016 at 18:15
  • The particles they used were 0.5 mm, which is about a thousand times larger than a typical bacterium.
    – Carey Gregory
    Commented Jul 25, 2016 at 18:25
  • With the opposing forces at play the only way they could go up the stream is through fluid forces, hence the physics slant on my answer; bacteria just don't swim that fast.
    – John
    Commented Jul 25, 2016 at 18:26

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