The struggle to control infectious diseases has become increasingly difficult due to resistance to current antibiotics and the co-existence of multiplying and non-multiplying bacteria, which makes it an urgent task to discover new antibiotic targets and to develop new antibiotics. Hydrogenases are found in micro-organisms belonging to the archaea and bacteria domains, which can catalyse the reversible oxidation of hydrogen gas (H 2 ↔2H + +2e) and play pleiotropic roles in microbial survival. Studies have shown that H 2 is a potent antioxidant and can selectively neutralize OH • (hydroxyl radicals). OH • , however, has been implicated as one of the mechanisms whereby bactericidal antibiotics and professional phagocytes kill bacteria. Thus we have enough reason to speculate that hydrogenases and H 2 are conducive to increasing the virulence and antibiotic resistance of bacteria, and hydrogenase inhibitors would help control bacterial infection.