Prevalência das famílias TEM, SHV e CTX-M de β-lactamases de espectro estendido em Escherichia coli e Klebsiella spp no Hospital Universitário de Santa Maria, Estado do Rio Grande do Sul

Abstract

As β-lactamases de espectro estendido (ESBL) são enzimas capazes de hidrolisar penicilinas, cefalosporinas de primeira, segunda, terceira e quarta gerações e o monobactâmico aztreonam, mas não as cefamicinas e os carbapenens. Entretanto, Prevalência das famílias TEM, SHV e CTX-M de β-lactamases ABSTRACTIn this study, the distribution and prevalence of extended-spectrum β-lactamases belonging to the TEM, SHV and CTX-M families were estimated among samples of Escherichia coli and Klebsiella spp. at the university hospital of Santa Maria, Rio Grande do Sul. Over a 14-month period, 90 microorganisms were selected as likely ESBL producers. The isolates were subjected to confirmatory phenotype tests for the presence of ESBL. Through investigating the respective genes using the polymerase chain reaction, the ESBL types present in each microorganism were then determined. Fifty-five samples (61.1%) were confirmed as ESBL-positive by means of the combined disc method, and 57 (63.3%) were found to be ESBL producers by means of the double disc method. From the polymerase chain reaction, ESBLs of TEM and SHV types were more frequently present in Klebsiella pneumoniae, while ESBL of CTX-M type was more frequently present in Klebsiella oxytoca.Key-words: extended-spectrum β-lactamases. Escherichia coli. Klebsiella spp. polymerase chain reaction.são inibidas por inibidores de β-lactamases como ácido clavulânico, sulbactam e tazobactam. Esta propriedade é a base dos testes laboratoriais utilizados para a detecção in vitro dessas enzimas 17 18 . Klebsiella pneumoniae e Escherichia coli são as espécies mais comumente relacionadas como produtoras de ESBLs 8 17 .A maioria das ESBLs evoluiu a partir de mutações genéticas em β-lactamases clássicas (TEM-1, TEM-2 e SHV-1), originando principalmente variedades de ESBLs dos tipos TEM e SHV 17 . Contudo, uma nova família de ESBLs, a CTX-M, emergiu nos últimos anos, principalmente em Escherichia coli, e tem se tornado uma das mais prevalentes famílias dessas enzimas em muitos países 2 11 14 18 21 .A presença de ESBLs nos ambientes hospitalares e suas conseqüências nas estratégias de tratamento com antimicrobianos constitui um importante agravante para pacientes hospitalizados 20 .

Characterization of Virulence Factors in Enteroaggregative and Atypical Enteropathogenic <i>Escherichia coli</i> Strains Isolated from Children with Diarrhea

“…On the other hand, ESBL was found in most of the isolates: in our study, this factor was detected in 13 (68%). This result is similar to the other studies data, which show a big number of Escherichia coli samples with bla TEM and bla CTX-M genes [19][20][21]. One of the most important properties in pathogenic microorganisms is the resistance to bactericidal activity.…”

Multiresistance, beta-lactamase-encoding genes and bacterial diversity in hospital wastewater in Rio de Janeiro, Brazil

“…Among the beta‐lactamase‐encoding genes studied, bla TEM was characterized in the majority of ESBL‐producing isolates and was associated with TEM‐type ESBL. This enzyme group and SHV beta‐lactamases have long been known as an ESBL‐producing group of beta‐lactamases (Oliveira et al. 2009).…”

Post-neurosurgical meningitis caused by KPC-producing Klebsiella pneumoniae: report of two cases

“…The polymyxin B minimum inhibitory concentrations (MICs) were determined using the reference Clinical Laboratory Standards Institute broth microdilution method 6 . Genes coding for extended-spectrum β-lactamases ( bla - CTX-M , bla - TEM , bla - SHV ), carbapenemases ( bla - KPC , bla - OXA-48 ), and metallo-β-lactamases ( bla - NDM-1 , bla - IMP , bla - VIM ) were investigated using the polymerase chain reaction, as described previously 7 - 9 . Molecular typing was performed by multilocus sequence typing (MLST) 10 .…”