Carbapenem-hydrolysing -lactamase KPC-2 in Klebsiella pneumoniae isolated in Rio de Janeiro, Brazil

Abstract

The aim of this study was to characterize the KPC-type carbapenem-hydrolysing β-lactamase, extended-spectrum β-lactamases (ESBLs) and class 1 integrons among nosocomial Klebsiella pneumoniae isolated in Rio de Janeiro, Brazil. MICs were determined and isolates were screened for ESBLs, metallo-β-lactamases (MBLs) and class A carbapenemase-producing phenotypes. The main β-lactamases resistance genes (bla_TEM, bla_SHV, bla_CTX-M, bla_KPC, bla_IMP and bla_VIM) and class 1 integrons were detected by PCR followed by DNA sequencing. The genetic relatedness of isolates was determined by PFGE. All K. pneumoniae isolates were positive for ESBL and class A carbapenemase production and negative for MBL production. All isolates were resistant to all β-lactam antibiotics, ciprofloxacin and gentamicin, being susceptible only to tigecycline and polymyxin B. The bla_KPC-2, bla_CTX-M-1, bla_CTX-M-2, bla_CTX-M-8 and bla_SHV-11 genes were detected. PFGE analysis revealed two clonal types among KPC-producing isolates, both identified in the same hospital. Our findings should alert medical authorities to implement stringent methods for the detection and spread control of emerging KPC-2 carbapenemases in the hospital setting in Brazil.