What kind of bacterial/virus could cause middle ear problem? where are they come from? food? air?blood?

Several: Adeno-, rhino-viruses and non-typable h.Flu, pneumococcus, moraxella, staph are bacteria that can cause infection. The virus usually causes the initial infection, and the patient is colonized with the bacteria that secondarily infects the middle ear. These diseases are transmitted by hand to mouth contact from another infected host, the same as a cold. Not from blood, food.