What bacteria cause halitosis?

Many. There are several strains of bacteria (check out the web) that can cause halitosis/bad breath.) Halitosis is common is usually caused by an accumulation of bacteria in the mouth as a result of gum disease, food, or plaque. Some people are more prone to have halitosis, regardless of how well they clean. Do your best, and brush the tongue too.
Only 1 good solution. I have been treating bad breath patients for over 30 years. The main goal here is to completely eliminate odor producing bacteria , unfortunately brushing and flossing an mouthwash does not provide long lasting effect, due to a fact that it only mechanically removes very small fraction of bacteria from your mouth. We have been utilizing full mouth detox and other methods and can achieve 98% succes.