Molecular Epidemiological Analysis of
            <i>Escherichia coli</i>
            Isolates Producing Extended-Spectrum β-Lactamases for Identification of Nosocomial Outbreaks in Stockholm, Sweden

Fang, Hong; Lundberg, Christer; Olsson‐Liljequist, Barbro; Hedin, G.; Lindbäck, Emma; Rosenberg, Åsa; Struwe, Johan

doi:10.1128/jcm.42.12.5917-5920.2004

Cited by 42 publications

(22 citation statements)

References 18 publications

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“…Thus, this endemic strain might have undergone genetic alterations over time and site. Clone 1 was also one of the clones involved in the first ESBL outbreak reported in Sweden 2002 (8). Clone 2 was another clone involved in the outbreak 2002; however, no more such strains were recovered after the outbreak during this study period.…”

Section: Discussionmentioning

confidence: 99%

“…All isolates were screened for the resistance genes SHV, TEM, CTX-M, and OXA by a multiplex PCR assay using universal primers (Table 1) (3,8,12,15). Bacterial DNA extraction was performed in a MagNA Pure LC System (Roche Diagnostics GmbH, Mannheim, Germany) by using a MagNA Pure LC DNA isolation kit I. PCR amplification reactions were performed in a volume of 25 l containing 12.5 l of 2ϫ Qiagen Multiplex PCR Master Mix (Qiagen GmbH, Hilden, Germany), 0.2 M concentrations of each primer, and 2 l of DNA template.…”

Section: Methodsmentioning

confidence: 99%

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Molecular Epidemiology of Extended-Spectrum β-Lactamases among Escherichia coli Isolates Collected in a Swedish Hospital and Its Associated Health Care Facilities from 2001 to 2006

et al. 2008

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The genetic characteristics and molecular epidemiology of extended-spectrum ␤-lactamases (ESBLs) among Escherichia coli isolates were investigated at a general hospital and its associated health care facilities in Stockholm, Sweden, during the period from 2001 to 2006. Of 87 consecutive nonduplicate ESBL-positive isolates, 80 isolates encoded CTX-M-type ESBLs, 64 of which were group 1 enzymes. TEM-type and OXA-type ␤-lactamases were encoded in 63 and 59% of the ESBL isolates, respectively. Pulsed-field gel electrophoresis (PFGE) analysis revealed 40 different pulsotypes, consisting of 11 clones accounting for 66% of all isolates, and 29 unique patterns. Moreover, of the 11 clones, clones 1 and 4 comprised half of the clonally related isolates (28 of 57). Clone 1 was a persistent endemic clone in the area throughout the years, and clone 4 emerged in 2003. However, in recent years, clone 1 isolates were no longer predominant and were gradually replaced by new emerging strains. Concerning ␤-lactamase gene profiles in relation to PFGE pulsotypes, clone-related bla profiles were observed in certain clones, while in most cases different bla profiles could be observed in the same clone, and the same bla profile could be present in different clones. The molecular epidemiology of ESBLpositive E. coli in the area shows shifts in predominant strains and increased clonal diversity over time. The study also indicated that both clonal spread of epidemic strains and transfer of transposable genetic elements might contribute to the proliferation of ESBLs.Extended-spectrum ␤-lactamases (ESBLs) are the major cause of resistance to oxyimino-cephalosporins in Enterobacteriaceae (4). ESBLs are mostly plasmid-mediated bacterial enzymes that are able to hydrolyze a wide variety of penicillins and cephalosporins. Most ESBLs have evolved by genetic mutation from native ␤-lactamases, particularly TEM-1, TEM-2, and SHV-1. These parent enzymes are commonly found in gram-negative bacteria, particularly in Enterobacteriaceae (4). Until the 2000s, most of the ESBLs were structurally related to the narrow-spectrum TEM-and SHV-type ␤-lactamases, with one to several amino acid substitutions surrounding their active site (4). The genetic mutations that give rise to ESBLs broaden the parental resistance pattern to a phenotype that includes resistance to broad-spectrum cephalosporins (e.g., cefotaxime [CTX] and ceftazidime [CAZ]) and monobactams (e.g., aztreonam) (9). Furthermore, in the late 1990s, a novel type of ESBLs, the CTX-M enzymes, emerged worldwide, mostly from Escherichia coli (2, 4). The more than 50 CTX-M enzymes thus far reported may be grouped into five main subgroups according to amino acid sequence similarity (CTX-M-1, CTM-M-2, CTX-M-8, CTX-M-9, and CTX-M-25) (2). Most of the CTX-Ms hydrolyze CTX better than CAZ. However, several CTX-Ms, including CTX-M-15, which is now the most widespread CTX-M enzyme worldwide (5, 10, 13, 21, 23), also hydrolyze CAZ efficiently (17). The OXA-type enzymes are another growing family of ESBLs and ar...

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Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Molecular Epidemiology of Extended-Spectrum β-Lactamases among Escherichia coli Isolates Collected in a Swedish Hospital and Its Associated Health Care Facilities from 2001 to 2006

et al. 2008

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“…A worldwide distribution of these enzymes has been reported (4), and in some settings (e.g., Argentina, Greece, Japan, Spain, and Taiwan), the CTX-M-type enzymes are more prevalent than TEM-and SHV-type ESBLs (35,36,43,45,46). In Europe, where the TEM-and SHV-type ESBLs were first reported (20,40) and are widespread overall (12,26,30,33,37), a rapid and massive dissemination of isolates producing CTX-M-type ESBLs has recently been reported in some countries (1,16,17,21,25,44) and is a matter of major concern.…”

mentioning

confidence: 99%

CTX-M-Type Extended-Spectrum β-Lactamases in Italy: Molecular Epidemiology of an Emerging Countrywide Problem

Mugnaioli

Luzzaro

Luca

et al. 2006

Antimicrob Agents Chemother

117

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A nationwide survey of extended-spectrum ␤-lactamase (ESBL) production among Enterobacteriaceae, carried out in 2003, showed that CTX-M-type enzymes have achieved a sizeable prevalence among ESBL producers in Italy, mostly in Escherichia coli and, to a lesser extent, in Klebsiella pneumoniae. In this work, we report on the molecular epidemiology of the CTX-M-producing isolates from that survey and on the mechanisms of dissemination of these emerging resistance determinants. The CTX-M-producing isolates were detected in 10 of the 11 participating centers distributed across the Italian national territory, although at remarkably variable rates in different centers (1.2 to 49.5% of the ESBL producers). All CTX-M determinants were of group 1, with CTX-M-15 and CTX-M-1 being the most prevalent variants (60% and 35%, respectively) and CTX-M-32 carried by a minority (5%) of isolates. Each variant was detected both in E. coli and in K. pneumoniae. Genotyping of the CTX-M-producing isolates by random amplification of polymorphic DNA revealed a notable diversity, especially among those producing CTX-M-1, while clonal expansion was evident with some CTX-M-15-producing strains. Mating experiments revealed a higher overall transferability of bla CTX-M-1 and bla CTX-M-32 than of bla CTX-M-15 . Coresistance to quinolones and aminoglycosides was overall higher with the CTX-M-15-producing isolates. The present results indicate that CTX-M-producing strains are now widespread across the Italian territory and underscore the emerging role of these ESBL determinants in the European setting. They also reveal notable differences in the dissemination mechanisms of genes encoding different CTX-M variants of the same lineage.

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“…One of these enzymes, CTX-M-15, is now found worldwide, mainly in Escherichia coli isolates recovered in hospitals and in the community and responsible for outbreaks in France, the United Kingdom, Sweden, and Canada (11,12,25,28,29,30,33,40). Molecular characterization of plasmids encoding CTX-M-15 from E. coli strains involved in outbreaks in different countries showed that they additionally carried other antibiotic resistance genes, such as bla OXA-1 , bla TEM-1 , tetA, aac(6Ј)-Ib, and aac(3)-II, and sometimes a class 1 integron (6,23,27).…”

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Emergence and Outbreaks of CTX-M β-Lactamase-Producing Escherichia coli and Klebsiella pneumoniae Strains in a Tunisian Hospital

et al. 2006

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Molecular Epidemiological Analysis of Escherichia coli Isolates Producing Extended-Spectrum β-Lactamases for Identification of Nosocomial Outbreaks in Stockholm, Sweden

Cited by 42 publications

References 18 publications

Molecular Epidemiology of Extended-Spectrum β-Lactamases among Escherichia coli Isolates Collected in a Swedish Hospital and Its Associated Health Care Facilities from 2001 to 2006

Molecular Epidemiology of Extended-Spectrum β-Lactamases among Escherichia coli Isolates Collected in a Swedish Hospital and Its Associated Health Care Facilities from 2001 to 2006

CTX-M-Type Extended-Spectrum β-Lactamases in Italy: Molecular Epidemiology of an Emerging Countrywide Problem

Emergence and Outbreaks of CTX-M β-Lactamase-Producing Escherichia coli and Klebsiella pneumoniae Strains in a Tunisian Hospital

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