Resistance of Klebsiella pneumoniae Strains Carrying bla NDM-1 Gene and the Genetic Environment of bla NDM-1

Regional dissemination is the major cause of the widespread prevalence of a plasmid-encoding NDM-1 enzyme. We investigated the drug resistance, joint efficiency, and gene environment of a strain carrying gene. Carbapenem-non-susceptible strains were analyzed using the VITEK 2 Compact. Strains carrying were identified using polymerase chain reaction and sequencing. Antimicrobial susceptibility testing and plasmid conjugation experiments were then conducted. Strains carrying were subjected to Southern blot analysis. After the gene mapping of , library construction, and sequencing, plasmids were subsequently spliced and genotyped using the software Glimmer 3.0, and then analyzed using Mauve software. Among 1735 carbapenem-non-susceptible strains, 54 strains of -positive bacteria were identified, which consisted of 44 strains of , 8 strains of and 2 strains of . Strains carrying had a resistance rate of more than 50% in most antibiotics. Plasmid conjugation between strains carrying and strain J53 had a success rate of 50%. Southern blot analysis indicated that each strain had multiple plasmids containing . Among the five plasmids containing in for sequencing, two plasmids with complete sequences were obtained. The findings were as follows: (i) The p11106 and p12 plasmids were highly similar to pNDM-BTR; (ii) the p11106 and p12 plasmids showed differences in the 20-30 kb region (orf00032-orf00043) from the other six plasmids; and (iii) was located at orf00037, while was found at orf00038. Two genes were located in the upstream region, and orf00052 ( ) in the 36 kb region was in the downstream sequence. -containing bacteria exhibit multidrug resistance, which rapidly spreads and is transferred through efficient plasmid conjugation; the multidrug resistance of these bacteria may be determined by analyzing their drug-resistant plasmids. The presence of and genes suggests a possible hypothesis that originates from , which is retained in over a long period by transposition of mobile elements.