Method of treating retained pulmonary secretions

A method of combatting Mycobacterium tuberculosis infection in a subject in need of such treatment, comprising administering to the lungs of the subject a lantibiotic or a pharmaceutically acceptable salt thereof in an amount effective to combat M. tuberculosis infection,

• wherein said subject is afflicted with a drug resistant strain of M. tuberculosis:
• wherein said lantibiotic is delivered by administering an aerosol of respirable particles containing said lantibiotic to said subject;
• wherein said aerosol is comprised of particles having a particle size within the range of from about 0.5 to 10 microns;
• wherein said lantibiotic is administered in an amount sufficient to achieve concentrations of said lantibiotic on the airway surfaces of said subject of from about 10.sup.-9 moles/liter to about 10.sup.-3 moles/liter;
• and
• wherein said lantibiotic is selected from the group consisting of duramycin, nisin, subtilin, epidermin, Pep 5, gallidermin, mersacidin, actagardine, cinnamycin, and ancovenin.