Well if it has been there for two months (I am assuming you have tried to treat it), it is probably bacterial and not fungal. One of the worst probable bacteria that it could be would be MRSA. These bacteria are typically resistant to many different antibiotics. Some of the other common bacterial causes include: Staphylococcus aureus, Staphylococcus saprophyticus, Klebsiella, Enterobacter, and the Proteus species