At least two men may have come down with a rare bacterial skin infection that is hard to treat with antibiotics after getting tattoos at a store in Seattle, US health authorities said Wednesday. One 44-year-old man was confirmed to have a case of Mycobacterium haemophilum after getting a tattoo on his arm in the western US city in August 2009, the Centers for Disease Control and Prevention said. The infection, which showed up as a bumpy red rash and a pus infection on the skin\'s surface, resisted treatment with several antibiotics but eventually disappeared after nine months. A second suspected case was reported in a 35-year-old man who got a tattoo at the same place two months later, but tests were inconclusive. The CDC said it considered it a \"suspected\" instance of infection. The source of the bacteria remains a mystery. Authorities said the tattoo parlor was in compliance with safety regulations but told the owner to use sterilized water for rinsing skin and diluting ink instead of tap water.