Multiclonal dispersal of KPC genes following the emergence of non-ST258 KPC-producing Klebsiella pneumoniae clones in Madrid, Spain

Received 15 January 2013; returned 21 February 2013; revised 16 May2013; accepted 21 May2013Objectives: ToanalysetheongoingepidemiologyofKPC-producingEnterobacteriaceaeafteranon-ST258KPC-3-producing Klebsiella pneumoniae outbreak in a university hospital in Madrid, Spain.Methods: Enterobacterial isolates (one per patient based on bacterial identification and typing patterns) withcarbapenem MICs higher than the EUCASTepidemiological cut-off values, a positive modified Hodge test andcarbapenem/boronic acid combination disc test results were studied (16 March 2010 to 31 January 2012) andcompared with KPC-producing isolates previously described in our institution (September 2009 to February2010). The bacterial population structure (PFGE and multilocus sequence typing), carbapenemase genes andKPC plasmids were studied. Patients’ clinical records werereviewed.Results: Twenty-fourKPC-producingEnterobacteriaceae(20 K.pneumoniae,2Escherichiacoliand2Enterobactercloacae)from23patients(13males,medianage72 years)werestudied.MostKPC-producerstrainswereconsid-eredascolonizers.SixK.pneumoniaeclones(ST11,ST20,ST384,ST454,ST659andST971),twoE.coliclones(ST224and ST357) and one E. cloacae clonewere identified. bla