Description of In116, the first blaCTX-M-2-containing complex class 1 integron found in Morganella morganii isolates from Buenos Aires, Argentina

J Antimicrob Chemother. 2005 Apr;55(4):461-5. doi: 10.1093/jac/dkh556. Epub 2005 Mar 2.


Objectives: We analysed the architecture and probable origin of a class 1 integron from cefotaxime-resistant Morganella morganii isolates.

Methods: bla genes and class 1 integron elements were detected by PCR and DNA-DNA hybridization in a M. morganii strain isolated in 1996. PCR-mapping and sequencing of different fragments were carried out to determine the integron's architecture.

Results and conclusions: A class 1 integron (In116), strongly related to the In6/In7 family, was detected in a plasmid from an oxyimino-cephalosporin-resistant M. morganii strain, producing CTX-M-2 beta-lactamase. The variable region of In116 contains aacA4, bla(OXA-2) and orfD cassettes. Downstream of the 3'-conserved-segment (3'-CS), an orf513-containing common region is followed by bla(CTX-M-2) and flanking regions, having 96-99% nucleotide identity with Kluyvera ascorbata's kluA-1 and neighbouring sequences. Some of the evidence supporting the incorporation of foreign DNA is as follows: a partial deletion in a second 3'-CS (3'-CS2), and the absence of 59-base element or IS-like structures upstream of bla(CTX-M-2).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Argentina
  • Cefotaxime
  • Cephalosporin Resistance
  • Chromosome Mapping
  • Integrons / genetics*
  • Molecular Sequence Data
  • Morganella morganii / drug effects*
  • Morganella morganii / genetics*
  • Plasmids / genetics
  • beta-Lactamases / genetics
  • beta-Lactamases / metabolism*


  • beta-lactamase CTX-2
  • beta-Lactamases
  • Cefotaxime

Associated data

  • GENBANK/AJ621187