Resumo

Gram negative bacteria producing New Delhi Metallo-β-lactamase (NDM) is one of the major public health concerns as a result of the hydrolysis of a broad variety of β-lactams including carbapenems, inducing a limitation for patient treatment. Since the first description of NDM-1 carbapenemase in Brazil in 2013, an active surveillance in search of NDM-producing bacteria began in most of health care units in this country. Here we report the detection of six NDM-producing Klebsiella pneumoniae isolates from Rio de Janeiro state, southern region of Brazil. Bacterial identification was performed by conventional techniques and antibiotic susceptibility was determined by disc diffusion method and Etest. Phenotypic carbapenemase production was tested by double-disk diffusion test (DDT) with EDTA and the presence of carbapenemase genes (bla_KPC, bla_NDM) and ESBL genes (bla_TEM, bla_SHV, bla_CTX-M) was identified by PCR and sequencing. MLST and PFGE (XbaI) were carried out to characterize the strains relatedness. Six isolates were recovered between September 2013 and April 2014 from surveillance rectal swabs (2 isolates), urine (2 isolates) and blood (2 isolates) samples from non-consecutive patients of the same hospital of Campos city (northern of Rio de Janeiro state). Although the strains were collected at the same hospital in a short period of time, the PFGE analysis classified them into 4 pulsotypes (named A–D). Three isolates (CCBH15668, CCBH15669 and CCBH15948) belonged to the same pulsotype (C). All strains were positive for metallo-β-lactamase production and harbored bla_NDM-1, bla_CTX-M (bla_CTX-M-2 or bla_CTX-M-15), bla_TEM (bla_TEM-1 or bla_TEM-15) and bla_SHV (bla_SHV-11 or bla_SHV-99). All isolates showed resistance to cefoxitin, piperacillin/tazobactam, ceftazidime, cefotaxime, cefepime, ertapenem, gentamicin, ciprofloxacin and sulfamethoxazole/trimethoprim. Resistance to aztreonam, amikacin and polymixin B were observed in 83,5%, 66,5%, 16,5% respectively. The isolates were considered not susceptible to meropenem and imipenem. Nevertheless, all the isolates remained susceptible to fosfomycin/trometamol. The detection of bla_NDM-1 in distinct K. pneumoniae pulsotypes, in the same hospital, indicates a rapid and easy spread. We also highlight the presence of an NDM-producing K. pneumoniae polymyxin B resistant which increases a concern since the therapeutic options become more limited.