Extended-Spectrum β-Lactamases of the CTX-M Type Now in Switzerland

Abstract

The epidemiology of clavulanic acid-inhibited extended-spectrum ␤-lactamases (ESBLs) was investigated among infection-associated enterobacterial isolates at the University Hospital in Lausanne, Switzerland, from January 2004 to June 2005. Out of 57 nonrepetitive ESBL producers (prevalence rate of 0.7%), 45 produced CTX-M-like ESBLs. CTX-M enzymes were mostly from clonally nonrelated Escherichia coli isolates, from urinary infections and community-acquired infections. Pediatric patients (20 out of 57) accounted for a large number of CTX-M producers. CTX-M-15 was the most frequent CTX-M-type enzyme. The plasmid-located bla CTX-M genes were associated with either ISEcp1 or ISCR1 insertion sequences. This study is the first published report of CTX-M-type ␤-lactamases in Switzerland.Plasmid-mediated extended-spectrum ␤-lactamases (ESBLs) were first identified in a Klebsiella pneumoniae isolate in Germany in 1983 (14). Since then, ESBL-positive Enterobacteriaceae have been isolated worldwide mostly from hospitalized patients (18). These enzymes hydrolyze significantly expandedspectrum cephalosporins such as cefotaxime and ceftazidime and the monobactam aztreonam, sparing carbapenems. Their activity is inhibited in vitro by clavulanic acid. Until the 2000s, most of the ESBLs were structurally related to the narrowspectrum TEM-and SHV-type ␤-lactamases, with one to several amino acid substitutions surrounding their active site (18). Beginning in the late 1990s, novel types of ESBLs, the CTX-M enzymes, emerged worldwide, mostly from Escherichia coli. The CTX-Ms are mostly from community-acquired isolates (2,22). The over 50 CTX-M enzymes so far reported may be grouped into five main subgroups according to amino acid sequence identity (CTX-M-1, -M-2, -M-8, -M-9, and -M-25) (2). Most of the CTX-Ms hydrolyze cefotaxime better than ceftazidime. However, several CTX-Ms including CTX-M-15 (2, 12, 25), which is now the most widespread CTX-M enzyme worldwide (6), hydrolyze ceftazidime efficiently (25).Since those CTX-Ms are reported increasingly in France (8,15,17,26), Italy (4,20), and recently Austria (9), it was interesting to search for those enzymes in Switzerland, a country known to have a strict policy of antibiotic prescription and to have an overall low level of multidrug resistance in bacteria (10).The aim of the present study was to estimate the prevalence and the type of the ESBLs produced by enterobacterial isolates among nonrepetitive clinical isolates over an 18-month period from January 2004 to June 2005 at the University Hospital of Lausanne, Switzerland. MATERIALS AND METHODSBacterial isolates. ESBL-producing enterobacterial isolates resulted from the screening of 8,259 enterobacterial isolates obtained from infection samples that were sent to the Department of Microbiology of the Lausanne University Hospital, Switzerland, from January 2004 to June 2005. Isolates were first identified by using the Vitek2 system (bioMérieux SA, Marcy-l'Etoile, France). Electrocompetent E. coli TOP10 (Invitrogen, Cergy Pontoise, ...

Enterobactérias produtoras de ESBL em Passo Fundo, estado do Rio Grande do Sul, Brasil

“…Os principais gêneros produtores de ESBLs, dentre as enterobactérias, são Escherichia coli, Klebsiella pneumoniae, Proteus sp, Providencia sp e Enterobacter sp 2 . Enterobactérias produtoras de ESBLs estão amplamente disseminadas, já tendo sido reportadas na França, Estados Unidos, Reino Unido, Grécia, Holanda, Hungria, Portugal, Bolívia, Peru, Brasil, entre outros [9][10][11][12][13] .…”

Charakterisierung der extended spectrum b-Lactamasen (ESBL) und Bestimmung der von Kindern isolierten uropathogenen Virulenzfaktoren von Escherichia coli (E. coli) Stämmen

“…SHV-5 β-lactamase is widespread in Middle and East Europe and has been previously described in Austria [40], Germany genes. Thus, the by far most prevalent ESBL found in E. coli isolates in Croatia was SHV-5, which is in contrast with reports from many other countries in which CTX-M β-lactamases appear to be the most frequent type [6][7][8][9][10][11][12][13]. Recent studies found very high prevalence of CTX-M β-lactamases in Croatia which reached 60% in hospital isolates of K. pneumoniae…”

“…In contrast to TEM or SHV-ESBLs CTX-M β-lactamases are native ESBLs and are derived from the chromosomal β-lactamases of the genus Kluyvera [4][5]. Over 50 CTX-M enzymes have been described so far, which can be grouped into five main subgroups according to amino acid sequence identity (CTX-M-1, CTX-M-2, CTX-M-8, CTX-M-9 and CTX-M-25) [6]. Most CTX-M β-lactamases hydrolyze cefotaxime better than ceftazidime, but some of them such as CTX-M-15 hydrolyze also ceftazidime efficiently [6].…”

“…Over 50 CTX-M enzymes have been described so far, which can be grouped into five main subgroups according to amino acid sequence identity (CTX-M-1, CTX-M-2, CTX-M-8, CTX-M-9 and CTX-M-25) [6]. Most CTX-M β-lactamases hydrolyze cefotaxime better than ceftazidime, but some of them such as CTX-M-15 hydrolyze also ceftazidime efficiently [6]. In some countries CTX-M β-lactamases are the most prevalent types of ESBLs, for instance in Russia [7], Greece [8], Spain [9], Switzerland [6], Japan [10], Taiwan [11], China [12] and Argentina [13].…”

“…Most CTX-M β-lactamases hydrolyze cefotaxime better than ceftazidime, but some of them such as CTX-M-15 hydrolyze also ceftazidime efficiently [6]. In some countries CTX-M β-lactamases are the most prevalent types of ESBLs, for instance in Russia [7], Greece [8], Spain [9], Switzerland [6], Japan [10], Taiwan [11], China [12] and Argentina [13]. ESBL producing Enterobacteriaceae are described with increasing frequency as causative agents of urinary tract infections (UTIs) [14][15][16][17].…”