Molecular Characterization of Extended-Spectrum Beta-Lactamases Produced by Clinical Isolates of Klebsiella pneumoniae and Escherichia coli from a Korean Nationwide Survey

Abstract

To determine the prevalence and genotypes of extended-spectrum beta-lactamases (ESBLs) among clinical isolates of Klebsiella pneumoniae and Escherichia coli, we performed antibiotic susceptibility testing, pI determination, induction testing, transconjugation, and DNA sequencing analysis. Among the 509 isolates collected from 13 university hospitals in Korea, 39.2% produced ESBLs. ESBL-producing isolates were detected in every region in Korea. A total of 44.6% of the isolates produced both TEM-and SHV-type ESBLs, and 52% of ESBL-producing isolates transferred resistance to ceftazidime by transconjugation. The ESBLs were TEM-19, TEM-20, TEM-52, SHV-2a, SHV-12, and one new variant identified for the first time in Korea, namely, TEM-116. TEM-1 and SHV-12 were by far the most common variants. TEM-1, TEM-116, and SHV-12 showed a high prevalence in K. pneumoniae. Two isolates (E. coli SH16 and K. pneumoniae SV3) produced CMY-1-like beta-lactamases, which play a decisive role in resistance to cefoxitin and cefotetan, as well as TEM-type enzymes (TEM-20 and TEM-52, respectively). Using MIC patterns and DNA sequencing analysis, we postulated a possible evolution scheme among TEM-type beta-lactamases in Korea: from TEM-1 to TEM-19, from TEM-19 to TEM-20, and from TEM-20 to TEM-52.

Molecular Epidemiology and Virulence Characteristics of Klebsiella pneumoniae Strains Isolated from Hospital-Associated Infections

“…A surveillance study developed in a University Hospital in Turkey reveals a prevalence of 57.1% Klebsiella pneumoniae ESBL producing strains [23] whereas the general circulation of these strains is of 33-86%. A nationwide survey in Korea aiming to detect the prevalence of ESBL Klebsiella pneumoniae producing strains identified 29% resistance to ceftazidime and 32% to cefotaxime [24]. Our study indicates a large circulation of strains resistant to more than three antibiotics.…”

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

“…A ocorrência de mais de um tipo de ESBL em um mesmo isolado é bastante comum, sendo a associação mais frequente a dos tipos TEM e SHV 10 Neste estudo, os métodos fenotípicos constataram que 67,8% dos isolados eram produtores de ESBLs, entretanto, pelo método molecular (PCR) este percentual foi de 93,3%; a comparação entre os métodos revelou pelo Teste para Proporções Populacionais p diferenças significativas (p<0,0001). Por outro lado, empregando-se o teste do qui-quadrado de Independência, demonstrou-se que as ESBLs dos tipos TEM e SHV (detecção molecular) estão associadas aos testes fenotípicos positivos (p<0,05).…”

Prevalence and Characterization of Extended Spectrum Beta-Lactamase Production in Clinical Isolates of Klebsiella pneumonia

“…[52]. Whereas studies from China [33] Korea [36] and India [12,53] reported TEM to be more prevalent than SHV.…”

“…It was further increased to 77.8% in 2009 [33]. ESBL production of Klebsiella pneumoniae from Thailand ranged from 44.4%-100% [34,35] and Korea 30% [36]. Another Asian Country Iran showed an increase in ESBL production by Klebsiella pneumoniae of 52.5% in 2008 [37] to 59.2% in 2009 [38], reaching 96% by 2010 [39].…”