Answer:
I'm a bacteria that causes typhoid What's my name ?
It doesn't live within a house, nor does it live without. Most will use it when they come in, and again when they go out.
It holds no blessings in disguise. Its rhymes are aimed at your demise, it's cast only to ruin, Whatever you are doin'.
My first master has four legs, my second master has two. My first I serve in life, my second I serve in death. Tough I am, yet soft beside. Against ladies cheeks I often reside.
What goes up but never comes down?
If itβs information you seek, come and see me. If itβs pairs of letters you need, I have consecutively three. What am I?