CMY-2-producing Salmonella enterica, Klebsiella pneumoniae, Klebsiella oxytoca, Proteus mirabilis and Escherichia coli strains isolated in Spain (October 1999-December 2000)

CMY-2 plasmid-mediated AmpC beta -lactamase (CMY-2) was detected in 21 isol ates from two hospitals located in different geographical regions of Spain between October 1999 and December 2000. The isolates comprised two Salmonel la enterica serovars (Mikawasima and Montevideo), 16 Escherichia coli, one Klebsiella pneumoniae, one Klebsiella oxytoca and one Proteus mirabilis. In addition to the expected resistance to beta -lactams, including extended-s pectrum cephalosporins and cefoxitin, all isolates showed a broad spectrum of associated resistance. All were resistant to sulfamethoxazole, chloramph enicol, tetracycline and streptomycin, and all but two were also resistant to gentamicin. Five isolates were studied in detail and all transferred CMY -2 and other resistance determinants by conjugation. Genomic DNA restrictio n pattern analysis of the E. coli isolates excluded the dissemination of a single clone. To the best of our knowledge this is the first time that CMY- 2 has been detected in P. mirabilis, K. oxytoca and S. enterica serovars Mi kawasima and Montevideo. It is also the first time that CMY-2 has been desc ribed in Spain.