Africa Health Research Institute, or AHRI (IMAGE) University of Alabama at Birmingham Caption A new culprit -- hydrogen sulfide -- has been found for the deadly infectious disease tuberculosis. When tuberculosis bacteria invade the lung, the amounts of hydrogen sulfide in the lung microenvironment greatly increase, and this makes the microbe more virulent and better able to block the body's protective immune response. The source of this hydrogen sulfide? Mycobacterium tuberculosis bacteria, or Mtb, are able to induce human macrophage immune cells to produce more hydrogen sulfide. Credit AHRI Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.