Dissemination of the mobilised RND efflux pump gene cluster tmexCD-toprJ among Klebsiella pneumoniae

By active nationwide surveillance in China together with online data mining, Ning Dong and colleagues1 found that tmexCD-toprJ encoding a transmissible resistance-nodulation-division (RND) family efflux pump has disseminated among diverse species of clinically important pathogens including Pseudomonas spp, Klebsiella spp, Aeromonas spp, and Proteus spp. Recently, tmexCD1-toprJ1-positive K pneumoniae has been widely discovered in samples from patients, animals, and food in China,2 conferring multidrug resistance, particularly to tigecycline, one of the last-line antimicrobials against multidrug-resistant Enterobacteriaceae.