Distribution and Spread of the Mobilized RND Efflux Pump Gene Cluster tmexCD-toprJ in Klebsiella pneumoniae from Different Sources.

In this study, we screened the gene cluster among 1,541 samples obtained from patients, healthy individuals, companion animals, pigs, chicken, and pork and chicken meat in Yangzhou, China. As a result, nine strains from humans, animals, and foods were positive for , which was located on plasmids or the chromosome. Seven different sequence types (STs) were identified, including ST15 ( = 2), ST580, ST1944, ST2294, ST5982, ST6262 ( = 2), and ST6265. All the positive strains were clustered into two distinct clades, and they shared a 24,087-bp core structure of , bounded by IS in the same orientation. IS could facilitate rapid and wide dissemination of in from various sources. Tigecycline has been regarded as one of the last-resort antibiotics available for the treatment of infections caused by carbapenem-resistant . The plasmid-mediated resistance-nodulation-division-type efflux pump gene cluster - is a newly identified tigecycline resistance determinant. In this study, we revealed that has disseminated among Klebsiella pneumoniae strains from poultry, food markets, and patients. It is critical to strengthen continuous monitoring, and control measures should be implemented to prevent the further dissemination of .