Suggest Remedy For Reoccuring Cellulitis Infections

Hi, I have been suffering from reoccuring cellulitis infections now sense April. Everytime I get an open wound, including my 4 year old peircing and my newly done tattoo had gotten infected. This is now my 6th case of it and doctors are not helping as they did tests for everything they could think of it being including MRSA and HIV .. It is starting to get very scary but mostly frustrating to have to keep going back whenever I have a cellulitis infection to get treatment. This started randomly in April and now whenever I have the slighest opened wound, i get an infection. I am a big believer in tattoos and have been getting tattood sense I was 16 by a very trusted tattoo artist and have 9 tattoos and only these 2 recent ones have gotten infected so I know its not a cause of the tattoo. I just want to understand what this could be and ever I will ever be rid of it?