Molecular epidemiology of Klebsiella pneumoniae resistant to beta-lactams antibiotics isolated from health centers of Aragua State-Venezuela

Abstract

K. pneumoniae resistance to β-lactam antibiotics is a public health problem. The objective was to characterize by molecular epidemiology isolates of K. pneumoniae resistant to β-lactams in four Health Centers of the Aragua State and establish the association between genotypes with resistance and epidemiological variables. 72 strains of K. pneumoniae were processed and their resistance to β-lactams was performed according to the CLSI guidelines. Double disc synergy was used for phenotypic detection of Extended Spectrum β-lactamase or ESBL. Combinations of EDTA/imipenem/meropenem; phenylboronic acid/meropenem/imipenem and piperacillin tazobactam/ ceftazidime/Imipenem/cefoxitin were used to detect metallo-beta-lactamase or MBLs, carbapenemases (KPC) and inducible AmpC respectively. Molecular typing was performed by polymerase chain reaction of palindromic extragenic repetitive sequences. Only 35 strains (48.6%) were resistant to all β-lactams. 34.29%; 31.43% and 31.43% turned out to be ESBL, KPC and MBLs respectively, and 2.86% inducible AmpC. Seven genotypes were identified, where type B grouped 23 genetically identical strains and clonally spreaded. A statistically significant relationship was found between genotype, age and gender. In conclusion, K. pneumoniae is highly resistant to β-lactams.

Keywords

• klebsiella pneumoniae, epidemiología molecular, resistencia antibiótica, beta-lactamasas