The unique adaptability of most uropathogens - a result of natural selection for the challenging environment they live in - makes them hard to get rid of, once they 'get a grip' and embedded bio-film-protected bacteria cause persistent problems.
E.Coli, the cause of approximately ninety percent of bladder infections, is a well-studied acid-tolerant bacterium that is present in the human intestine, even in new-born babies.
E.Coli can survive in acidic environments that are lethal to other pathogens, such as in fermented foods like sausage and apple cider. It also survives and even thrives in acidic urine conditions with a PH as low as 2.
Drinking cranberry juice, orange juice, alcohol or anything which acidifies the urine consequently is likely to be counterproductive if you know you have an E.Coli bladder infection.
But E.Coli is not all bad. Non-pathogenic E.Coli is one of our most prolific intestinal flora, and it plays an essential part in the processing of food and waste materials. E.Coli is therefore useful to us, and we even make use of it medically.
For example, it is used for genetic engineering, since cultures of E.Coli can be made to produce unlimited quantities of the product of an introduced gene and important drugs such as insulin can be manufactured in E. coli.
Unfortunately, E.Coli is also one of the most dangerous bugs we could have chosen to have a symbiotic relationship with. It is a fast mutator, since it multiplies at an enormous rate (in the right conditions doubling the colony size approximately every 20 minutes) and it is 'opportunist', being non-fussy about where it lives and breeds. It will happily live and breed on equipment, on your hands, in your mouth, on any mucous membrane, in your hair, in your bladder, on towels, on door handles, toilet seats, in your water filter etc.
It is thought, for example, that E.Coli can thrive with or without oxygen, in almost any conditions, including boiling that it can hibernate in freezing temperatures almost indefinitely. The E.Coli bug is therefore both creiophilic (can survive freezing, so watch those ice cubes when you are on holiday abroad) and thermophilic (can survive boiling, so that towel may not be as clean as you think...) and you won't kill it by washing something in warm soapy water. In fact, it can even live on soap. You can, however, flush it away, and more on that later...
E.Coli has an amazing affinity with the bodies of warm blooded animals like us. The entire bug (the variety that can stick to the bladder) is covered with molecular hairs (fimbria or pili with lectins). These molecular hairs stick like velcro to the cell walls of body tissue and anything else with the correctly orienteD-Mannose molecules (like D-Mannose ).
The bug expresses fimbria quickly in demanding conditions. It's like a human realising they were in the water, and growing fins and gills, or like a human slipping down the face of a cliff, and growing hooks and climbing tackle right out of our skin.
We do have mechanisms that offer a defence against these processes and actually produce human beta-defensin-1, an antimicrobial peptide implicated in the resistance of epithelial surfaces to microbial colonization and that helps to break the fimbria/pili that E.Coli use to attach.
But E.Coli is uniquely adapted to survive and can quickly mutate to resist our natural defences and antibiotics.
Small amounts of D-Mannose can be found in cranberry but we know that cranberry contains very little mannose. But worse than the fact that very little is found is the acidifying effect of drinking cranberry or acidifying the urine in any way may help bacteria thrive.
Now comes the interesting bit. E.Coli like to attach to a sugar-type substance called D-Mannose, which our body produces naturally, and is particularly abundant in the bladder and urinary tract, providing ideal docking ports for E.Coli.
We don't have perfect bodies, and nature has really messed things up here, because if it weren't for the D-Mannose in the cell walls, any E.Coli that managed to get up the urethra would be flushed away in normal urination. But they are not. They get up there, and they find a docking port, and they start to multiply. And that's when the trouble begins. They burrow their way into the walls of the bladder, which somehow doesn't recognise them as enemies, but embraces them as if they were fond friends. It is one of the bacterial survival mechanisms. It is their job to perpetuate their genes. Burying themselves in the bladder wall helps them to create repeat attacks of cystitis, multiplying their numbers in exponential profusion.
In this photo the E.Coli are the 'docked' white egg-shaped cells. The E.Coli bacteria are attracted to the D-Mannose in the cell walls. D-Mannose by providing a greater source of Ingested D-Mannose that will all leave the bladder during urination can support a healthy bladder by occupying the E.Coli lectins, preventing attachment and carrying attached bacteria away.
The cell walls of the E.Coli bacterium are covered with minute fimbria (hairs) with lectins (molecular projections) that hook like Velcro to the mannose in the walls of the bladder and urinary tract.
Unit 7, Pyramid Court
York, YO26 5NB