Colistin is the drug-of-last-resort...only deployed when all other anti-bacterial agents fail. Recently...though...Carbapenem-resistant Klebsiella pneumoniae withstood the Colistin application. Somehow...in a colony of those wee beasties...there are some that have identified* baterial heteroresistance to Colistin...making them unstopable.
*The SCIENCE DEPT. of this BLOG has commenced engineering a compound which will do what Colistin can't. Indeed...with the new software developed by this BLOG...the resistance-aspect is identified...a compound is devloped within 24 hours...and...deployed accordingly with magificent results. In one test...the pneumonia-stricken patient recovered from what would have othewise been a death-bed bout with the GRIM REEPER,(WSJ A-3;03-07-18).