Staph, or Staphylococcus, is a family of bacteria that is very virulent, contagious, and even possibly infectious. What makes staph so dangerous is that it is very resistant to antibiotics.
Though staph is not generally considered an air-borne disease, there is some debate that MRSA, thought it usually is spread through contact with open sores, can remain viable on dry counters for several hours, that it may be spread by close proximity to someone that is infected by breathing the same air.
More research needs to be done to determine the avenues of transmission to be sure if it can be spread through the air.