Question

Pathogenic organisms do not include _____.

bacteria
viruses
rickettsiae
ticks

Answer 1

A pathogenic organism is a bacterium, fungus, prion or virus that survives by feeding off of a host. A pathogenic organism typically causes disease in the host organism.
The answer is Ticks. Ticks can be infected with disease.

Answer 2

A list of non-pathogenic bacteria is an outline of the types of bacteria that do not cause illnesses in humans. They include:
staphylococcus
lactobacillus
Escherichia coli
bifidobacteria
bacteroides
Brevibacterium linens

In Short, it's A. Bacteria