Effects of abnormal growth, and pressure, in the brain

I will preface this by stating I am a writer; and my question is reference for my current story.  However, I want the symptoms of my disease to be as accurate as possible--I don't want to have symptoms that make no sense.

In advance, I thank you for helping me with what some may think trivial, but for me is very important.

My senario:
Over the course of 10 years, a bacteria spreads as a minor irritant, becoming as prolific and common as influenza or the cold.  However, over the course of five years the bacteria evolved, becoming progressively more resistant to cleansers and drugs, and developing more severe symptoms.

The final known evolution of the bacteria led to dramatic effects on the human brain—abnormal growth in the Hypothalamus and Amygdala, crushing the Hippocampus and putting increasing pressure on the Frontal, Parietal, and Temporal Lobes.

(Additional Question:  Can a bacteria Do this?  I'm a little lost on the differences between bacteria and viruses.)