For years, pathogens’ resis­tance to antibi­otics has put them one step ahead of researchers, which is causing a public health crisis. But now scientists have discovered a new antibi­otic that elim­i­nates pathogens without encoun­tering any detectable resistance — a finding that chal­lenges long-held sci­en­tific beliefs and holds great promise for treating chronic infec­tions like tuber­cu­losis and those caused by MRSA.