Graham Shepherd <muhero at globalnet.co.uk> wrote in article
<69vp3v$l93$1 at heliodor.xara.net>...
> The problem is usually to STOP the bacteria growing - urine is nutritious
> carbon and nitrogen sources, salts, all sorts of other stuff...
>Then why is human urine usually sterile, and bladder infections relatively
rare? I thought the pH was usually too low, the carbon in a form that is
energetically speaking relatively inaccessible, and the concentration of
the salts high enough to cause dehydration problems. I can understand
diluted urine outside the body being a fairly good medium for many kinds of
bacterial growth, but I don't see that being true for undiluted urine in
the relatively anaerobic human bladder.