CTX-M-type β-lactamases: an emerging group of extended-spectrum enzymes

Tzouvelekis, L. S.; Tzelepi, E.; Tassios, Panayotis T.; Legakis, Nicholas J.

doi:10.1016/s0924-8579(99)00165-x

Cited by 242 publications

(214 citation statements)

References 23 publications

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“…Interestingly, intermediate or highlevel resistance to amoxicillin-clavulanate was more common among CTX-M producers (96.4% of E. coli isolates and 90.8% of K. pneumoniae isolates) than among strains producing non-CTX-M-type ESBLs (80.0% of E. coli isolates and 75.8% of K. pneumoniae isolates), whereas resistance to piperacillin-tazobactam was conversely less frequent among CTX-M producers (17.9% of E. coli isolates and 37.9% of K. pneumoniae isolates) than among strains producing non-CTX-M-type ESBLs (36.0% of E. coli isolates and 48.4% of K. pneumoniae isolates). The greater activity of piperacillin-tazobactam against CTX-M-positive strains is probably explained by the fact that the CTX-M enzymes are better inhibited by tazobactam than by clavulanate (10,35,37).…”

Section: Resultsmentioning

confidence: 99%

Prevalence and Molecular Epidemiology of CTX-MExtended-Spectrum β-Lactamase-Producing Escherichia coli and Klebsiella pneumoniae in RussianHospitals

Edelstein

Pimkin

Palagin

et al. 2003

Antimicrob Agents Chemother

327

181

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A total of 904 consecutive nosocomial isolates of Escherichia coli and Klebsiella pneumoniae collected from 28 Russian hospitals were screened for production of extended-spectrum ␤-lactamases (ESBLs). The ESBL phenotype was detected in 78 (15.8%) E. coli and 248 (60.8%) K. pneumoniae isolates. One hundred fifteen isolates carried the genes for CTX-M-type ␤-lactamases, which, as shown by PCR-restriction fragment length polymorphism analysis, were distributed into the two genetic groups of CTX-M-1 (93%)-and CTX-M-2 (7%)-related enzymes. Isolates producing the enzymes of the first group were found in 20 hospitals from geographically distant regions of the country and were characterized by considerable diversity of genetic types, as was demonstrated by enterobacterial repetitive consensus PCR typing. Within this group the CTX-M-3 and the CTX-M-15 ␤-lactamases were identified. In contrast, the enzymes of the CTX-M-2 group (namely, CTX-M-5) were detected only in eight clonally related E. coli isolates from a single hospital. Notably, the levels of resistance to ceftazidime were remarkably variable among the CTX-M producers. This study provides further evidence of the global dissemination of CTX-M type ESBLs and emphasizes the need for their epidemiological monitoring.During the past decade extended-spectrum ␤-lactamases (ESBLs) of the CTX-M type emerged in many countries of the world. The first organisms producing ␤-lactamases of this type were identified both as single and epidemic clinical isolates in very distant geographic regions (Germany and France and Argentina) in the early 1990s (3, 5, 7). More recently, a rapid increase in the proportion of multiple CTX-M variants to the TEM-and SHV-derived ESBLs has been reported in many hospitals in Spain (9,12,15,35) (14), and Korea (28). Furthermore, CTX-M ␤-lactamases, mainly types CTX-M-2 and CTX-M-3, were found to be widespread or even predominant ESBL types in several countries, including Argentina (31, 34; M. Galas, F. Pasteran, R. Melano, A. Petroni, G. Lopez, A. Corso, A. Rossi, et al., Abstr. 38th Intersci. Conf. Antimicrob. Agents Chemother., abstr. E-109, 1998), Japan (41), and Poland (1).Currently the CTX-M family includes more than 20 ␤-lactamases, which may be grouped on the basis of sequence similarity into four distinct clusters (subtypes) epitomized by CTX-M-1, CTX-M-2, CTX-M-8, and CTX-M-9 (26, 37; http: //www.lahey.org/studies/webt.htm). Within each cluster there is a high degree of bla CTX-M gene sequence identity (Ͼ95%), although members of different subtypes share only 70 to 77% similarity at the nucleotide level. The recent finding of Kluyvera ascorbata species-specific ␤-lactamases (KluA) which share 98.6 to 100% identity with CTX-M-2 and CTX-M-5 and analysis of DNA sequences adjacent to the KluA-and CTX-Mcoding genes provide strong evidence of the direct evolution of the CTX-M-2 cluster from the chromosomal enzyme of K. ascorbata (20,36). Likewise, the chromosomal KLUG-1 enzyme of Kluyvera georgiana was found to be the most-probable progenitor of ...

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Section: Resultsmentioning

confidence: 99%

Prevalence and Molecular Epidemiology of CTX-MExtended-Spectrum β-Lactamase-Producing Escherichia coli and Klebsiella pneumoniae in RussianHospitals

Edelstein

Pimkin

Palagin

et al. 2003

Antimicrob Agents Chemother

327

181

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“…Accurate sizing of PCR products has been used for Mycobacterium tuberculosis typing and PCR product analysis to differentiate AmpC â-lactamases (Evans et al, 2004;PerezPerez & Hanson, 2002;Tzouvelekis et al, 2000). The application of the DHPLC WAVE technology to the analysis of multiplex PCR products developed in this study has clear advantages.…”

Section: Evaluation Of Multiplex Pcr With Clinical Isolatesmentioning

confidence: 96%

“…The sequences from six strains, three from group 8 (CTX-M-8, CTX-M-40 and CTX-M-41) and three from group 25/26 (CTX-M-25, -26 and -39), were aligned together. They have previously all been classified within group 8 (Tzouvelekis et al, 2000) and consequently this study will identify groups 8 and 25/26 as one group. The group-specific primer sets were designed in the highly conserved region of the alignments.…”

Section: Identification Of Bla Ctx-m Subgroup-specific Primersmentioning

confidence: 99%

Rapid and simple detection of bla CTX−M genes by multiplex PCR assay

Ensor

Gossain

et al. 2005

Journal of Medical Microbiology

111

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A novel multiplex PCR assay is described (CTX-Mplex PCR) that allows rapid detection of bla CTX-M genes and discrimination between groups 1, 2, 9 and 25/26. The specificity and sensitivity of the assay were evaluated with 10 control strains and then applied to 62 clinical isolates. The multiplex PCR detected and classified bla CTX-M genes with 100 % accuracy. The utilization of a denaturing HPLC WAVE system to size the PCR products automatically from the multiplex PCR enhances the assay by saving time and costs.

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“…Rather than arising by mutation, they represent examples of plasmid acquisition of the b lactamases genes which are found on the chromosomes of the Kluyvera species. CTX-M was 1st detected in E.coli strains in Germany (1988) and presently, there are more than 65 allelic variants which are known [2,3].…”

Section: Microbiology Sectionmentioning

confidence: 99%

Occurrence of the CTX-M, SHV and the TEM Genes Among the Extended Spectrum b-Lactamase Producing Isolates of Enterobacteriaceae in a Tertiary Care Hospital of North India

Kaur

Aggarwal²

2013

JCDR

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Purpose: The present study was carried out to assess the prevalence of the Extended Spectrum Beta Lactamases (ESBLs) and to characterize the ESBL types which were prevalent in our hospital.Material Methods: Five hundred gram negative isolates which belonged to the family, Enterobacteriaceae, which were isolated during the study period of 2009 to 2011, were investigated for ESBL production. Clinical isolates from urine (344), pus (109), blood (15), IV/ central line tip (10), sputum (12) and body fluid (10) specimens were processed. The organisms which were identified, included E.coli (351), Klebsiella pneumoniae (74), Klebsiella oxytoca (21), Proteus mirabilis (15), Proteus vulgaris (9) , Enterobacter spp (15) and Citrobacterspp (15). Antimicrobial susceptibility testing was done. The ESBL detection was carried out for all the isolates by the CLSI confirmatory method. The MIC of ceftazidime and ceftazidime plus clavulanic acid was determined by the E-test. Molecular typing of the ESBLs was performed by multiplex PCR among 93 ESBL isolates.Results: 45.8% isolates were found to be ESBL producers by the CLSI confirmatory method and they were confirmed by the E-test ESBL strips. A majority of E.coli in the study possessed the CTX-M genes (59.32%). Among the Klebsiella isolates, a majority were co producers of the ESBL genes; either 2 or all the 3 genes co-existed together.

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CTX-M-type β-lactamases: an emerging group of extended-spectrum enzymes

Cited by 242 publications

References 23 publications

Prevalence and Molecular Epidemiology of CTX-MExtended-Spectrum β-Lactamase-Producing Escherichia coli and Klebsiella pneumoniae in RussianHospitals

Prevalence and Molecular Epidemiology of CTX-MExtended-Spectrum β-Lactamase-Producing Escherichia coli and Klebsiella pneumoniae in RussianHospitals

Rapid and simple detection of bla CTX−M genes by multiplex PCR assay

Occurrence of the CTX-M, SHV and the TEM Genes Among the Extended Spectrum b-Lactamase Producing Isolates of Enterobacteriaceae in a Tertiary Care Hospital of North India

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