Genetic Factors Associated with Enhanced bla KPC Expression in Tn3/Tn4401 Chimeras.

ABSTRACT: The expression of the bla KPC gene plays a key role in carbapenem resistance in Enterobacteriaceae However, the genetic regulators of the bla KPC gene have not been completely elucidated, especially the genes in Tn3-Tn4401 chimeras. Two novel Tn3-Tn4401 chimera isoforms were characterized in our hospital, isoform A (CTA), which harbors a 121-bp deletion containing the PX promoter and was present in 22.6% (54/239) of isolates, and isoform C (CTC), which harbors a 624-bp insertion and a P1 promoter deletion and was present in only 1 isolate. The carbapenem MICs of both isoforms were 2-fold or more higher than those of the wild type (Tn3-Tn4401 chimera, CTB), and bla KPC was most highly expressed in CTA. Bioinformatics and 5' rapid amplification of cDNA ends (5' RACE) experiments indicated a novel strong putative promoter, PY, at the 3' end of the ISKpn8 gene. PY mutation nearly abrogated bla KPC expression (P?

SUBMITTER: Huang J 

PROVIDER: S-EPMC7038255 | biostudies-literature | 2020 Feb

REPOSITORIES: biostudies-literature