I found this that might help , it appears that germ are just 'nasty' bacteria
Bacteria are one of the five types of microbes1. Many bacteria are helpful to humans. They aid in our digestion, producing vitamin K and helping to break down food. They are used to make products such as cheese, butter, and yogurt. They are used to make many kinds of beneficial drugs, including insulin and antibiotics such as tetracycline and streptomycin. Nitrogen-fixing bacteria such as rhizobium in the soil are essential to life on Earth. Bacteria are used in sewage treatment plants, and tailored bacteria have been made that can clean up chemical and oil spills, and remove environmental pollutants from coal2.
Not all bacteria are benign, though. Bacteria cause many kinds of disease. Bacteria that cause disease are called pathogens. We sometimes refer to them as "germs" in everyday speech.