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


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).
Power
Pablo
P
Cátedra de Microbiología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 956 (1113), Buenos Aires, Argentina.
Galleni
Moreno
M
Di Conza
José
J
Ayala
Juan A
JA
Gutkind
Gabriel
G
D001118:Argentina; D002439:Cefotaxime; D018550:Cephalosporin Resistance; D002874:Chromosome Mapping; D032023:Integrons / Q000235:genetics*; D008969:Molecular Sequence Data; D020613:Morganella morganii / Q000187:drug effects* / Q000235:genetics*; D010957:Plasmids / Q000235:genetics; D001618:beta-Lactamases / Q000235:genetics / Q000378:metabolism*
C071167:beta-lactamase CTX-2; D001618:beta-Lactamases; D002439:Cefotaxime