However, when the bacteria enter other parts of the body they can cause many problems, especially if the person's immune system is weakened by a chronic disease or age. Wounds or irritation of the skin can cause staph infections that present as boils, impetigo, or cellulitis. Toxic shock syndrome can be caused by a staph infection as can conjunctivitis in the eye. Staph also can enter the bloodstream and cause serious illness. Because staph is a common infection, it often is treated with antibiotics, usually from the penicillin family.
Some staphylococcus become resistant to penicillin.
Methicillin is from the penicillin family. When an infection does not respond to methicillin, it is said to be resistant and physicians must select other antibiotics. This can be a dangerous situation if the infection cannot be stopped. Diarrhea caused by antibiotics I am taking an antibiotic to clear up an ear infection. This is the fourth antibiotic I have taken because the infection is quite resistant to treatment.