Researchers have discovered a new way to reverse antibiotic resistance in some bacteria using hydrogen sulphide (H2S). By adding H2S releasing compounds to Acinetobacter baumannii – a pathogenic bacteria that does not produce H2S on its own – they found that exogenous H2S sensitised the A. baumannii to multiple antibiotic classes. It was even able to reverse acquired resistance in A. baumannii to gentamicin.