The most common virus is the common cold, which is actually caused by several different families of viruses. Even though you may experience upper-respiratory symptoms associated with a bacterial infection, most cases of the common cold are not caused by bacteria-which make antibiotics useless against them.
Colon infection is caused when harmful bacteria resides in the colon. Normally, human immune system kills the harmful bacteria but there are some strains of bacteria that grow uninterruptedly even with strong immune system. When such bacteria overgrow in the large intestine, they can cause lot of complication.
What most people do not realize is that anaerobic bacteria are the primary cause of bad breath due to their ability to consume vast amounts of proteins and excrete foul-smelling volatile sulfur compounds as a result of rapidly digesting the proteins in the mouth.ost bacteria that are gram-negative are pathogens that cause diseases due to cell walls containing LPS (lipopolysaccharide) endotoxins. Some of these diseases include salmonella, Legionnaire's disease, cholera and severe halitosis.