Most bacteria are capable of producing hydrogen sulfide and use a trio of enzymes to do so. Classically, this gas was considered a by-product of sulfur metabolism, but knowing that nitric oxide protects Gram-positive bacteria against oxidative stress, Shatalin et al. (see the Perspective by Belenky and Collins) discovered that H2S probably does likewise. When the H2S-producing enzymes were inactivated, bacteria became more susceptible to antibiotics unless supplied with a source of H2S.
K. Shatalin, E. Shatalina, A. Mironov, E. Nudler, H2S: A universal defense against antibiotics in bacteria. Science 334, 986–990 (2011). [Abstract] [Full Text]
P. Belenky, J. J. Collins, Antioxidant strategies to tolerate antibiotics. Science 334, 915–916 (2011). [Abstract] [Full Text]
