Local health authorities are on a state of alert with the emergence of what is suspected to be a new form of tuberculosis bacterium, immune to existing medication or treatments. A researcher of the virulent disease said Wednesday that through genetic mutation, the new bacterium acquires an immunity to even the more potent tuberculosis treating drugs. Health authorities have estimated the current number of patients suffering from the disease nationwide at over four thousand. Authorities say a significant number of the three-thousand-300 annual tuberculosis-related deaths in South Korea are linked to the new bacterium. Among infectious diseases, tuberculosis is the second leading killer of adults in the world, with more than two million tuberculosis-related deaths each year.