Resumo

Since the first report in Brazil of Klebsiella pneumonia carbapenemase (KPC) in 2006, the rapid spread of carbapenem-non-susceptible Enterobacteriaceae throughout the country became one of major clinical and public health challenges and a great concern for antimicrobial resistance surveillance services. Considering patients admitted to health care units are submitted to constant antimicrobial therapy, culminating in a selective pressure, they can sometimes act as reservoirs to KPC-producing K. pneumoniae, since we know this species is present in the human gut microbiota. The aim of this study was to assess the antimicrobial resistance profile of KPC-producing K. pneumoniae isolates recovered from surveillance swabs from several regions of the country. 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 phenyl boronic acid. The presence of bla_KPC gene was performed by PCR. 128 MDR K. pneumoniae isolates recovered from rectal swab specimens of non-consecutive patients during 2007 to 2013 were randomly selected, the isolates were originated from ten states and one Federal District of four macro regions in Brazil. 111 strains harbored bla_KPC gene by PCR, 94% was positive to carbapenemase production by DDT. The average of resistance to all β-lactams and carbapenems was 97%. The antimicrobial profile showed isolates resistant to gentamicin (62%), ciprofloxacin (95%), sulfamethoxazole/trimethoprim (87%) and amikacin (38%). Nevertheless most of isolates remained susceptible to fosfomycin/trometamol, polymyxin B and tigecycline. Although the levels of resistance to the three carbapenems were high, the interpretation is confused when these three drugs are not tested simultaneously due to a reasonable percentage of intermediate resistance and susceptibility sometimes, either disk diffusion and Etest, which can lead mistakes in screening of carbapenemase-producing bacteria. Studies with isolates from intestinal colonization are poorly performed in Brazil, however it is significant to monitor the prevalence of antimicrobial resistance since the inpatients may serve as reservoirs for MDR strains, this study provides information for a better understanding the national dissemination of KPC-producing bacteria.