Resumo

Recently, a progressive increase in the carbapenem resistance due to carbapenemases has been observed. The KPC (Klebsiella pneumoniae carbapenemase) - producing organisms have been commonly found in Enterobacteriaceae. However, the presence of this enzyme in Morganella morganii is rarely reported. This work describes the presence blaKPC-2 gene in two clinical isolates of M. morganii from a university hospital for the first time in Brazil. The bacterial isolates were collected between November-December 2008, from blood cultures and urine samples. MIC was determined by broth microdilution according to recommendations of CLSI (2012). The search for beta-lactamase genes and the determination of the incompatibility group plasmid and the transposon Tn4401 isoform were performed with primers and conditions previously described. The clonal relationship between the isolates was determined by PFGE using the enzyme XbaI. Plasmid DNA was isolated according to protocol of Kieser and used to transform E.coli DH5α cells. Transformants were selected on Mueller Hinton agar containing ampicillin at 100ug/mL. Results of PFGE analysis revealed that the isolates showed the same genotypic profile. The isolates were susceptible only to ceftazidime, cefepime and meropenem. The transformants showed increased MIC values than the original isolates to third and fourth generation cephalosporins, monobactams, piperacillin-tazobactam, and the carbapenems imipenem and meropenem. All the isolates carried the aadB gene in the variable region of an class 1 integron, which confers resistance to gentamycin, kanamycin and tobramycin. On the other hand, the isolates showed no blaCTX-M, blaSHV or blaTEM genes. Transformed cells showed positive results for modified Hodge test and for blaKPC gene. Transformant cells showed the presence of incK plasmids. The region between the blaKPC-2 gene and ISKpn7 revealed no deletion, indicating the presence of the isoform Tn4401b. This study describes the first isolation of KPC-producing M. morganii in Brazil, which brings out the potential of this gene to easily disseminate.