A particularly dangerous antibiotic-resistant strain of bacteria linked to the routine use of antibiotics in animals is known as

These "miracle drugs" held at bay such mortifying diseases as pneumonia and tuberculosis, which had formerly been not treatable. But the steady evolution of defiant bacteria has resulted in a situation in which, for some illnesses, doctors now have only one or two drugs "of last resort" to take advantage against infections by superbugs resistant to all other drugs.