The complex genetic context of blaPER-1 flanked by miniature inverted-repeat transposable elements in Acinetobacter johnsonii

PLoS One. 2014 Feb 25;9(2):e90046. doi: 10.1371/journal.pone.0090046. eCollection 2014.

Abstract

On a large plasmid of Acinetobacter johnsonii strain XBB1 from hospital sewage, blaPER-1 and ISCR1 were found in a complex Tn402-like integron carrying an arr3-aacA4 cassette array. The integron was truncated by the same 439-bp miniature inverted-repeat transposable element (MITE) at both ends. blaPER-1 and its complex surroundings might have been mobilized by the MITEst into an orf of unknown function, evidenced by the presence of the characteristic 5-bp direct target repeats. The same 439-bp MITEs have also been found flanking class 1 integrons carrying metallo-β-lactamases genes bla IMP-1, bla IMP-5 and bla VIM-2 before but without ISCR1. Although the cassette arrays are different, integrons have always been truncated by the 439-bp MITEs at the exact same locations. The results suggested that MITEs might be able to mobilize class 1 integrons via transposition or homologous recombination and therefore represent a possible common mechanism for mobilizing antimicrobial resistance determinants.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acinetobacter / enzymology*
  • Acinetobacter / genetics*
  • Base Sequence
  • DNA Transposable Elements / genetics*
  • Inverted Repeat Sequences / genetics*
  • beta-Lactamases / genetics*

Substances

  • DNA Transposable Elements
  • beta-Lactamases

Grant support

This work was supported by a grant from the National Natural Science Foundation of China (project no. 81222025). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. No additional external funding was received for this study.