Emergence of Plasmid-Borne dfrA14 Trimethoprim Resistance Gene in Shigella sonnei.

ABSTRACT: The most common mechanism of trimethoprim (TMP)-resistance is the acquisition of dihydrofolate reductase enzyme resistant to this drug. Previous molecular characterization of TMP-genes resistance in Chilean isolates of Shigella sonnei searching for dfrA1 and dfrA8, showed solely the presence of dfrA8 (formerly dhfrIIIc). However, these genetic markers were absent in S. sonnei strains further isolated during an outbreak in 2009. To identify the TMP-resistance gene in these strains, a genomic DNA library from a TMP-resistant (TMP(R)) S. sonnei representative strain for the outbreak was used to clone, select and identify a TMP-resistance marker. The TMP(R) clone was sequenced by primer walking, identifying the presence of the dfrA14 gene in the sul2-strA'-dfrA14-'strA-strB gene arrangement, h

SUBMITTER: Miranda A 

PROVIDER: S-EPMC4951496 | biostudies-literature | 2016

REPOSITORIES: biostudies-literature