NPR.org has a segment on the alarming rise of multi-drug resistant Klebsiella pneumoniae. And more here. The evolution of MDR Klebsiella is of course a man-made phenomenon. Antibiotic overuse has resulted in the evolution of resistance in bacteria from Acinobacter to Yersinia. Klebsiella pneumoniae and Enterobacteriaceae are examples of hospital-acquired pathogens that have also undergone virulence evolution. Close proximity of debilitated hospitalized patients and ample attendant-borne opportunities for transmission have exerted selection for increased virulence and have allowed horizontal transmission of resistance alleles between non-related bacteria. Listen to the NPR piece and then scroll over to the Evolution and Medicine Review to read about one potential solution: sequential selection from antibiotic cycling leading to reversion to ancestral antibiotic resistance alleles. Miriam Barlow and colleagues are providing a needed bit of good news on resistance evolution. Their work in applied evolutionary medicine is a piece of the bigger puzzle of how to harness microbial evolution to preserve antibiotic effectiveness and limit virulence.