There isn't a definitive conclusion about what makes candida albicans to mutate to its fungal pathogenic form. It is true that an alkaline Ph favor the mutation in the case of albicans species. Science is still battling to understand what cause the yeast to change to its fungal form, but isn't the Ph the only requirement. Changes in temperature are even more important according to the latest research.
This is another study pointing to candida albicans ability to change its external Ph. Even in an acid PH, the yeast can alter it in less than 12 hours to become fungal. The acid doesn't offer any security. http://mbio.asm.org/content/2/3/e00055-11
As you see, there isn't only one known cause so far.