Genotypic detection and molecular epidemiology of extended-spectrum β-lactamase-producing Escherichia coli and Klebsiella pneumoniae in a regional hospital in central Taiwan

Abstract

This study was conducted to detect the genes encoding extended-spectrum b-lactamases (ESBLs) and determine the epidemiological relatedness of 69 Escherichia coli and 33 Klebsiella pneumoniae isolates collected from a regional hospital in central Taiwan, mostly from inpatients (E. coli 87.0 %; K. pneumoniae 88.0 %). The phenotypes of these isolates were examined according to the combination disc method recommended by the Clinical and Laboratory Standards Institute. Most of the ESBL-producing E. coli and K. pneumoniae isolates (98.6 % and 97 %, respectively) could be detected using cefotaxime discs with and without clavulanate. Genotyping was performed by PCR with type-specific primers. CTX-M-14 type (53.6 %) was the most prevalent ESBL among E. coli isolates while SHV type (57.6 %) was the most dominant among K. pneumoniae isolates. Six E. coli and three K. pneumoniae isolates did not carry genes encoding ESBLs of types TEM, SHV, CTX-M-3, CTX-M-14, CMY-2 and DHA-1. The co-existence of two or more kinds of ESBL in a single isolate was common, occurring in 40.6 % and 72.7 % of E. coli and K. pneumoniae isolates, respectively. PFGE analysis revealed that ESBL producers isolated in this setting were genetically divergent. INTRODUCTIONSince the first report in Germany in 1983 (Knothe et al., 1983), the emergence of extended-spectrum b-lactamase (ESBL)-producing Klebsiella pneumoniae and Escherichia coli has become a serious problem in hospitalized patients worldwide (Hawser et al., 2009;Livermore et al., 2007;Paterson & Bonomo, 2005). In Taiwan, the prevalence of ESBL producers has increased in recent years, ranging from 8.5 to 50.7 % in K. pneumoniae and 1.5 to 25.4 % in E. coli (Jean et al., 2009;Kuo et al., 2008;Yu et al., 2006).According to Ambler's classification, ESBLs belong to the class A b-lactamases, which possess an active-site serine residue essential for the inactivation of b-lactam antimicrobial drugs (Ambler, 1980). The term 'extendedspectrum b-lactamase' was originally applied to describe the TEM and SHV variants that can hydrolyse oxyiminocephalosporins (Paterson & Bonomo, 2005). The 'extended spectrum' of activity is defined in terms of hydrolysing oxyimino-cephalosporins or aztreonam at more than 10 % of the activity of hydrolysing benzylpenicillin. Generally, ESBLs confer resistance to all penicillins, first-to-fourth generation cephalosporins and monobactams, but not to cephamycins or carbapenems. However, like many other class A b-lactamases, ESBLs are inactivated by the blactamase inhibitors, such as clavulanate (Bradford, 2001). Most of the genes encoding ESBLs are plasmid-borne and are often located in the transposons and integrons (Eckert et al., 2006), facilitating their mobilization with other resistance determinant. Thus the genes encoding ESBLs may be easily transferred between bacteria.The most prevalent ESBLs are included in three groups: TEM, SHV and CTX-M. The SHV enzymes are named Isoelectric focusing. Bacteria cultured in Mueller-Hinton broth for 20 h were centrifuged and the pellet...

Higher CTX-M, Tem, and SHV Extended-Spectrum Beta-Lactamase Plasmid Gene Combination Frequency in Esbl Producing Klebsiella Pneumoniae Compared With Esbl Producing Escherichia Coli

“…Plasmid CTX-M, TEM, and SHV extended-spectrum beta-lactamase gene frequency was higher in this study than in other literature sources, namely: 1) in this study plasmid CTX-M was 97.06% compared to 73.8 -85.4% elsewhere; 2) plasmid TEM was 71.32% compared to elsewhere 42.4 -62.3%; and 3) plasmid SHV was 63.97% compared to the wide range of 7.7 -62.3% in the literature (Hayakawa et al, 2013;Lin, Hsu, Chen, Huang, & Lo, 2010;Manoharan, Premalatha, Chatterjee, & Mathai, 2011). In addition, plasmid gene combination frequency was higher, compared to other similar studies: CTX-M+ TEM+ SHV+ plasmid gene combination (45.59% vs 25.64%); and CTX-M+ TEM+ SHVplasmid gene combination (68.38% vs 26.5-35.5%; Hayakawa et al, 2013;Manoharan et al, 2011).…”

“…Other studies have demonstrated higher plasmid SHV gene frequency in the K. pneumoniae group, compared to the E. coli group (Manoharan et al, 2011), as well as slightly higher plasmid CTX-M gene frequency in the E. coli group and slightly higher plasmid TEM gene frequency in the K. pneumoniae group (Kargar et al, 2014;Lin, Hsu, Chen, Huang, & Lo, 2010).…”

First report of TEM-104-, SHV-99-, SHV-108-, and SHV-110-producing Klebsiella pneumoniae from Iran

“…The TEM enzyme was named after the patient from whom it was isolated, Temoneira, and was fi rst discovered in Escherichia coli in Greece. In addition, chromosomal-related CTX-Mtype ESBL was reported in Kluyvera ascorbata (11) . Detection of ESBL production is important, because ESBL-positive strains are associated with increased mortality as compared to ESBL-negative strains.…”

Molecular study of extended-spectrum beta-lactamase (TEM-1) gene in Escherichia Coli isolates collected from Ostad Alinasab Hospital in Tabriz Iran

“…This was 50% in our research. In Taiwan, Chinfulin et al (2010) reported the prevalence of TEM gene in 69 E.coli isolates [24]. Shazi shaki et al (2010) reported that TEM is the most common resistance gene in E.coli of Neonatal Intensive Care Units (NICU) of Indian hospitals [2]).…”