CARBAPENEM-HYDROLYSING BETA-LACTAMASE KPC IN KLEBSIELLA PNEUMONIAE FROM BLOODSTREAM INFECTIONS IN RECIFE, BRAZIL

Anna Carolina Soares Almeida (UPE); Felipe Lira de Sá Cavalcanti (UFPE); Marinalda Anselmo Vilela (UFPE); Marcos Antonio de Morais Júnior (UFPE); Morais Maria Camargo de Morais (UPE)

The plasmid-encoded KPC carbapenem-hydrolyzing enzymes are a group of recently identified carbapenemases that have emerged among gram-negative pathogens, particularly Klebsiella pneumoniae. The KPC family has attracted attention not only for their potential of spread but also for high mortality rates in bloodstream infections. Ten strains showing decreased susceptibility to extended-spectrum cephalosporin were isolated from bloodstream infections from patients hospitalized in teaching university hospital (HUOC) in Recife, Brazil. Antimicrobial susceptibility tests and modified Hodge test were performed as described by CLSI (2009). The presence of bla_KPC, bla_NMC-A, bla_IMI and bla_IMP was investigated by PCR using specific conditions and primers. The positive PCR products for bla_KPC were purified using the PCR Purification Kit (Promega). Sequencing was performed with the BigDye Terminator Cycle Sequencing Kit in ABI Prisma 3100 DNA Sequencer (Applied Biosystems). Sequences were compared with database of GenBank. Genetic relatedness of the isolates was evaluated by ERIC-PCR. The results showed that 60% of the isolates were positive only for bla_KPC gene, confirmed by sequencing. The susceptibility profile to antimicrobials showed 100% of resistance to first-, third and forth- generation cephalosporin and ertapenem; 84% to amikacin, aztreonam, cefoxitin, ciprofloxacin, piperacilin/tazobactam; 50% to imipenem and meropenem;  34% to gentamicin; 100% intermediate resistance to tigecycline and susceptible to polymyxin. This profile  is similar to those frequently found in KPC-producing isolates, which display resistance to non-beta-lactam antibiotics and usually susceptibility to tigecycline and polymyxin. This work confirmed that KPC-producing isolates may be clinically unrecognized since they not show “in vitro” resistance to carbapenems. In this study ertapenem was sensitive indicator of presence KPC. The resulting ERIC-PCR of KPC-producing K. pneumoniae showed that isolates were not clonally related, suggesting the spread was mediated by mobile elements, like plasmids or others. Our finding alerts to the necessity of surveillance strategies to contain  dissemination of this emergent resistance mechanism.