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

POWER PABLO; GALLENI MORENO; DI CONZA JOSÉ; AYALA JUAN; GUTKIND GABRIEL

JOURNAL OF ANTIMICROBIAL CHEMOTHERAPY

Oxford University Press.

Lugar: British; Año: 2005 vol. 55 p. 461 - 465

0305-7453

  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 b-lactamase. The variable region of In116 contains aacA4, blaOXA-2 and orfD cassettes. Downstream of the 3´- conserved-segment (3´-CS), an orf513-containing common region is followed by blaCTX-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 blaCTX-M-2.