Dissemination of CTX-M-Type β-Lactamases among Clinical Isolates of Enterobacteriaceae in Paris, France

ABSTRACT We analyzed 19 clinical isolates of the family Enterobacteriaceae (16 Escherichia coli isolates and 3 Klebsiella pneumoniae isolates) collected from four different hospitals in Paris, France, from 2000 to 2002. These strains had a particular extended-spectrum cephalosporin resistance profile characterized by a higher level of resistance to cefotaxime and aztreonam than to ceftazidime. The bla CTX-M genes encoding these β-lactamases were involved in this resistance, with a predominance of bla CTX-M-15. Ten of the 19 isolates produced both TEM-1- and CTX-M-type enzymes. One strain (E. coli TN13) expressed CMY-2, TEM-1, and CTX-M-14. bla CTX-M genes were found on large plasmids. In 15 cases the same insertion sequence, ISEcp1, was located upstream of the 5′ end of the bla CTX-M gene. In one case we identified an insertion sequence designated IS26. Examination of the other three bla CTX-M genes by cloning, sequencing, and PCR analysis revealed the presence of a complex sul1-type integron that includes open reading frame ORF513, which carries the bla gene and the surrounding DNA. Five isolates had the same plasmid DNA fingerprint, suggesting clonal dissemination of CTX-M-15-producing strains in the Paris area.

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Cloning and sequence analysis of the hemB gene of Staphylococcus aureus

Canadian Journal of Microbiology ◽

10.1139/m94-103 ◽

1994 ◽

Vol 40 (8) ◽

pp. 651-657 ◽

Cited By ~ 10

Author(s):

Badria Kafala ◽

A. Sasarman

Keyword(s):

Staphylococcus Aureus ◽

Biosynthetic Pathway ◽

Aminolevulinic Acid ◽

Colony Growth ◽

Reading Frame ◽

E Coli ◽

Preliminary Identification ◽

The Family ◽

Genes Encoding ◽

Porphobilinogen Synthase

The hemB gene is a member of the family of genes encoding enzymes of the porphyrin biosynthetic pathway and codes for the enzyme porphobilinogen synthase, which is responsible for the conversion of Δ-aminolevulinic acid to porphobilinogen. To clone the hemB gene of Staphylococcus aureus we used Tn917-mediated transposon mutagenesis. Tn917 confers resistance to erythromycin and is carried by plasmid pTV1ts, which has thermosensitive replication. Hem mutants were selected by growth in the presence of kanamycin and erythromycin at 43 °C. Preliminary identification of the hem mutants was based on their dwarf colony growth, which could be restored to normal by hemin. DNA extracted from one of the hem mutants was digested with several restriction endonucleases and hybridized to a probe representing the XbaI–AvaI end of Tn917. A BglII–EcoRI fragment of 4.5 kb gave a positive signal and was cloned into pUC18. Transformants were identified by colony hybridization with the Tn917 probe. The positive clones were sequenced, starting from the transposon end. The results allowed us to identify an open reading frame whose nucleotide sequence presented a homology of 63% to the sequence of the hemB gene of Bacillus subtilis and of 55% to the sequence of the hemB gene of Escherichia coli K12. No other nucleotide sequences, except those belonging to known hemB genes, presented significant homologies to our sequence. The cloning of the hemB gene of S. aureus was confirmed by the ability of the gene to complement a hemB mutant of E. coli K12. To our knowledge, this is the first report of the cloning of a hem gene in S. aureus.Key words: Δ-aminolevulinic acid dehydratase, hemB gene, S. aureus, heme, porphyrins.

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Cloning of Acyl-ACP Thioesterase FatA fromArachis hypogaeaL. and Its Expression inEscherichia coli

Journal of Biomedicine and Biotechnology ◽

10.1155/2012/652579 ◽

2012 ◽

Vol 2012 ◽

pp. 1-5 ◽

Cited By ~ 3

Author(s):

Gao Chen ◽

Zhen-ying Peng ◽

Lei Shan ◽

Ning Xuan ◽

Gui-ying Tang ◽

...

Keyword(s):

Oleic Acid ◽

Palmitoleic Acid ◽

Membrane Lipid ◽

Pcr Analysis ◽

Fatty Acid Profiles ◽

Reading Frame ◽

E Coli ◽

Real Time Quantitative Pcr ◽

Immature Seeds ◽

Expression Inescherichia Coli

In this study, a full-length cDNA of the acyl-ACP thioesterase,AhFatA, was cloned from developing seeds ofArachis hypogaeaL. by 3′-RACE. Sequence analysis showed that the open reading frame encodes a peptide of 372 amino acids and has 50–70% identity with FatA from other plants. Real-time quantitative PCR analysis revealed thatAhFatA was expressed in all tissues ofA. hypogaeaL., but most strongly in the immature seeds harvested at 60 days after pegging. Heterologous expression ofAhFatA inEscherichia coliaffected bacterial growth and changed the fatty acid profiles of the membrane lipid, resulting in directed accumulation towards palmitoleic acid and oleic acid. These results indicate that AhFatA is at least partially responsible for determining the high palmitoleic acid and oleic acid composition ofE. coli.

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Identification and Transcriptional Control of the Genes Encoding the Caulobacter crescentus ClpXP Protease

Journal of Bacteriology ◽

10.1128/jb.181.10.3039-3050.1999 ◽

1999 ◽

Vol 181 (10) ◽

pp. 3039-3050 ◽

Cited By ~ 29

Author(s):

Magne Østerås ◽

Agathe Stotz ◽

Stefanie Schmid Nuoffer ◽

Urs Jenal

Keyword(s):

Heat Shock ◽

Transcriptional Control ◽

Caulobacter Crescentus ◽

Activity Patterns ◽

Amino Acid Sequences ◽

Regulatory Subunit ◽

Regulatory Subunits ◽

Reading Frame ◽

E Coli ◽

Genes Encoding

ABSTRACT The region of the Caulobacter crescentus chromosome harboring the genes for the ClpXP protease was isolated and characterized. Comparison of the deduced amino acid sequences of theC. crescentus ClpP and ClpX proteins with those of their homologues from several gram-positive and gram-negative bacteria revealed stronger conservation for the ATPase regulatory subunit (ClpX) than for the peptidase subunit (ClpP). The C. crescentus clpX gene was shown by complementation analysis to be functional in Escherichia coli. However, clpX fromE. coli was not able to substitute for the essential nature of the clpX gene in C. crescentus. TheclpP and clpX genes are separated on theC. crescentus chromosome by an open reading frame pointing in the opposite direction from the clp genes, and transcription of clpP and clpX was found to be uncoupled. clpP is transcribed as a monocistronic unit with a promoter (PP1) located immediately upstream of the 5′ end of the gene and a terminator structure following its 3′ end. PP1 is under heat shock control and is induced upon entry of the cells into the stationary phase. At least three promoters forclpX (PX1, PX2, and PX3) were mapped in the clpP-clpX intergenic region. In contrast to PP1, the clpX promoters were found to be downregulated after heat shock but were also subject to growth phase control. In addition, the clpP andclpX promoters showed different activity patterns during the cell cycle. Together, these results demonstrate that the genes coding for the peptidase and the regulatory subunits of the ClpXP protease are under independent transcriptional control in C. crescentus. Determination of the numbers of ClpP and ClpX molecules per cell suggested that ClpX is the limiting component compared with ClpP.

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1216. Presence of the Narrow-Spectrum OXA-1 Beta-lactamase Enzyme Is Associated with Elevated Piperacillin-Tazobactam MIC Values Among ESBL-producing Escherichia coli Clinical Isolates (CANWARD, 2007-2018)

Open Forum Infectious Diseases ◽

10.1093/ofid/ofab466.1408 ◽

2021 ◽

Vol 8 (Supplement_1) ◽

pp. S697-S697

Author(s):

Andrew Walkty ◽

James Karlowsky ◽

Philippe Lagace-Wiens ◽

Alyssa Golden ◽

Melanie Baxter ◽

...

Keyword(s):

Escherichia Coli ◽

Clinical Isolates ◽

Beta Lactamase ◽

Gene Detection ◽

Research Support ◽

Extended Spectrum Beta Lactamase ◽

E Coli ◽

Narrow Spectrum ◽

The Family ◽

Lactamase Gene

Abstract Background The clinical outcome of patients with bacteremia due to an extended-spectrum beta-lactamase (ESBL)-producing member of the family Enterobacteriaceae who are treated with piperacillin-tazobactam appears to depend, at least in part, on the piperacillin-tazobactam MIC. The purpose of this study was to determine whether there is any association between the MIC of piperacillin-tazobactam and presence of the narrow spectrum OXA-1 beta-lactamase enzyme among ESBL-producing Escherichia coli. Methods E. coli clinical isolates were obtained from patients evaluated at hospitals across Canada (January 2007 to December 2018) as part of an ongoing national surveillance study (CANWARD). ESBL production was confirmed using the Clinical and Laboratory Standards Institute phenotypic method. Susceptibility testing was carried out using custom broth microdilution panels, and all isolates underwent whole genome sequencing for beta-lactamase gene detection. Results In total, 671 ESBL-producing E. coli were identified as part of the CANWARD study. The majority of isolates (92.0%; 617/671) harbored a CTX-M ESBL enzyme. CTX-M-15 (62.3%; 418/671), CTX-M-27 (13.9%; 93/671), and CTX-M-14 (13.4%; 90/671) were the most common variants identified. The narrow spectrum OXA-1 beta-lactamase enzyme was present in 42.6% (286/671) of isolates. OXA-1 was detected in 66.3% (277/418) of isolates with a CTX-M-15 ESBL enzyme versus only 3.6% (9/253) of isolates with other ESBL enzyme types. The piperacillin-tazobactam MIC50 and MIC90 values were 8 µg/mL and 32 µg/mL for isolates that possessed the OXA-1 enzyme versus 2 μg/mL and 8 µg/mL for those that did not. The percentage of ESBL-producing E. coli isolates that were inhibited by a piperacillin-tazobactam MIC of ≤8 μg/mL was 68.5% for isolates that were OXA-1 positive and 93.8% for isolates that were OXA-1 negative. Conclusion The MIC50 and MIC90 values of piperacillin-tazobactam among ESBL-producing E. coli were higher for the subset of isolates that harbored a narrow spectrum OXA-1 beta-lactamase enzyme relative to the subset that did not. This association was primarily observed among ESBL-producers with the CTX-M-15 enzyme variant. OXA-1 was infrequently detected among isolates with other ESBL enzyme types. Disclosures George Zhanel, PhD, AVIR (Grant/Research Support)Iterum (Grant/Research Support)Merck (Grant/Research Support)Pfizer (Grant/Research Support)Sandoz (Grant/Research Support)Sunovion (Grant/Research Support)Venatorx (Grant/Research Support)Verity (Grant/Research Support)

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CTX-M-14 and CTX-M-15 enzymes are the dominant type of extended-spectrum β-lactamase in clinical isolates of Escherichia coli from Korea

Journal of Medical Microbiology ◽

10.1099/jmm.0.004507-0 ◽

2009 ◽

Vol 58 (2) ◽

pp. 261-266 ◽

Cited By ~ 53

Author(s):

Wonkeun Song ◽

Hyukmin Lee ◽

Kyungwon Lee ◽

Seok Hoon Jeong ◽

Il Kwon Bae ◽

...

Keyword(s):

Escherichia Coli ◽

Hydrolytic Activity ◽

Common Type ◽

Clinical Isolates ◽

Confirmatory Test ◽

Dominant Type ◽

E Coli ◽

Extended Spectrum ◽

Genes Encoding ◽

M 14

This study was performed to assess the prevalence and genotypes of plasmid-borne extended-spectrum β-lactamases (ESBLs) and AmpC β-lactamases in Escherichia coli in Korea. A total of 576 isolates of E. coli was collected from 12 Korean hospitals during May and July 2007. A phenotypic confirmatory test detected ESBLs in 82 (14.2 %) of the 576 E. coli isolates. The most common types of ESBLs identified were CTX-M-14 (n=32) and CTX-M-15 (n=27). The prevalence and diversity of the CTX-M mutants, including CTX-M-15, CTX-M-27 and CTX-M-57, with significant hydrolytic activity against ceftazidime were increased. PCR experiments detected genes encoding plasmid-borne AmpC β-lactamases in 15/56 cefoxitin-intermediate or cefoxitin-resistant isolates, and the most common type of AmpC β-lactamase identified was DHA-1 (n=10). These data suggest that the incidence of ESBLs in E. coli has increased as a result of the dissemination of CTX-M enzymes in Korea. In addition, CTX-M-22, CTX-M-27 and CTX-M-57 have appeared in Korea.

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Phylogenetic association of fluoroquinolone and cephalosporin resistance of D-O1-ST648 Escherichia coli carrying bla CMY-2 from faecal samples of dogs in Japan

Journal of Medical Microbiology ◽

10.1099/jmm.0.054676-0 ◽

2014 ◽

Vol 63 (2) ◽

pp. 263-270 ◽

Cited By ~ 5

Author(s):

Toyotaka Sato ◽

Shin-ichi Yokota ◽

Torahiko Okubo ◽

Masaru Usui ◽

Nobuhiro Fujii ◽

...

Keyword(s):

Escherichia Coli ◽

Phylogenetic Group ◽

Clinical Isolates ◽

Dominant Group ◽

E Coli ◽

Faecal Samples ◽

Phylogenetic Grouping ◽

Cephalosporin Resistance ◽

Group D

This study aimed to investigate the genetic association between fluoroquinolone (FQ) and/or cephalosporin (CEP) resistance in Escherichia coli isolates from dogs, and the risk to human health. We characterized E. coli clinical isolates, derived from faecal samples of dogs attending veterinary hospitals, using phylogenetic grouping, determination of virulence factor (VF) prevalence, multilocus sequence typing (MLST) and O serotyping. The D group was the dominant phylogenetic group among strains resistant to FQ and/or CEP. In contrast, the dominant group among susceptible strains was group B2. Group D strains showed a significantly higher prevalence of VFs than strains belonging to groups A and B1, and were resistant to significantly more antimicrobials than group B2 strains. The phylogenetic distribution of FQ–CEP-resistant E. coli groups (FQ–CEPRECs) and FQ-resistant groups was significantly correlated (r = 0.98), but FQ–CEPRECs and CEP-resistant E. coli groups were not correlated (r = 0.58). Data from PFGE, O serotype and MLST analyses indicated that the majority of FQ-resistant strains derived from a particular lineage of phylogenetic group D: serotype O1 and sequence type (ST) 648. Some D-O1-ST648 strains carried bla CMY-2, showed multidrug resistance and possessed a higher prevalence of the VFs kspMT, ompT and PAI compared with other group D strains. Our data indicate that the emergence of FQ-CEP-resistant E. coli is based primarily on FQ-resistant E. coli. Moreover, as strains of the D-O1-ST648 lineage have been found in clinical isolates derived from humans at a relatively high frequency, our findings indicate that the spreading of D-O1-ST648 strains may cause serious difficulties in both veterinary and human clinical fields in the future.

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Clustering of the YNA1 gene encoding a Zn(II)2Cys6 transcriptional factor in the yeast Hansenula polymorpha with the nitrate assimilation genes YNT1, YNI1 and YNR1, and its involvement in their transcriptional activation

Biochemical Journal ◽

10.1042/bj3350647 ◽

1998 ◽

Vol 335 (3) ◽

pp. 647-652 ◽

Cited By ~ 35

Author(s):

Julio ÁVILA ◽

Celedonio GONZÁLEZ ◽

Nélida BRITO ◽

José M. SIVERIO

Keyword(s):

Transcriptional Activation ◽

Hansenula Polymorpha ◽

Nitrate Assimilation ◽

Transcriptional Factors ◽

Gene Encoding ◽

Reading Frame ◽

Transcription Start Sites ◽

The Family ◽

Genes Encoding ◽

Free Media

The genes encoding the nitrate transporter (YNT1), nitrite reductase (YNI1) and nitrate reductase (YNR1) are clustered in the yeast Hansenula polymorpha. In addition, DNA sequencing of the region containing these genes demonstrated that a new open reading frame called YNA1 (yeast nitrate assimilation) was located between YNR1 and YNI1. The YNA1 gene encodes a protein of 529 residues belonging to the family of Zn(II)2Cys6 fungal transcriptional factors, and has the highest similarity to the transcriptional factors encoded by nirA, and to a smaller extent to nit-4, involved in the nitrate induction of the gene involved in the assimilation of this compound in filamentous fungi. Northern blot analysis showed the presence of the YNA1 transcript in cells incubated in nitrate, nitrate plus ammonium, ammonium, and nitrogen-free media, with a decrease in its levels in those cells incubated in ammonium. In nitrate the strain Δyna1::URA3, with a disrupted YNA1 gene, neither grew nor expressed the genes YNT1, YNI1 and YNR1. In the gene cluster YNT1-YNI1-YNA1-YNR1, the four genes were transcribed independently in the YNT1 → YNR1 direction and the transcription start sites were determined by primer extension.

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Novel chromosomal insertions of ISEcp1-blaCTX-M-15 and diverse antimicrobial resistance genes in Zambian clinical isolates of Enterobacter cloacae and Escherichia coli

Antimicrobial Resistance and Infection Control ◽

10.1186/s13756-021-00941-8 ◽

2021 ◽

Vol 10 (1) ◽

Author(s):

Misheck Shawa ◽

Yoshikazu Furuta ◽

Gillan Mulenga ◽

Maron Mubanga ◽

Evans Mulenga ◽

...

Keyword(s):

Escherichia Coli ◽

Antimicrobial Resistance ◽

Chromosomal Location ◽

Enterobacter Cloacae ◽

Clinical Isolates ◽

E Coli ◽

Antimicrobial Resistance Genes ◽

Genes Encoding ◽

High Degree ◽

Genotypic Characteristics

Abstract Background The epidemiology of extended-spectrum β-lactamases (ESBLs) has undergone dramatic changes, with CTX-M-type enzymes prevailing over other types. blaCTX-M genes, encoding CTX-M-type ESBLs, are usually found on plasmids, but chromosomal location is becoming common. Given that blaCTX-M-harboring strains often exhibit multidrug resistance (MDR), it is important to investigate the association between chromosomally integrated blaCTX-M and the presence of additional antimicrobial resistance (AMR) genes, and to identify other relevant genetic elements. Methods A total of 46 clinical isolates of cefotaxime-resistant Enterobacteriaceae (1 Enterobacter cloacae, 9 Klebsiella pneumoniae, and 36 Escherichia coli) from Zambia were subjected to whole-genome sequencing (WGS) using MiSeq and MinION. By reconstructing nearly complete genomes, blaCTX-M genes were categorized as either chromosomal or plasmid-borne. Results WGS-based genotyping identified 58 AMR genes, including four blaCTX-M alleles (i.e., blaCTX-M-14, blaCTX-M-15, blaCTX-M-27, and blaCTX-M-55). Hierarchical clustering using selected phenotypic and genotypic characteristics suggested clonal dissemination of blaCTX-M genes. Out of 45 blaCTX-M gene-carrying strains, 7 harbored the gene in their chromosome. In one E. cloacae and three E. coli strains, chromosomal blaCTX-M-15 was located on insertions longer than 10 kb. These insertions were bounded by ISEcp1 at one end, exhibited a high degree of nucleotide sequence homology with previously reported plasmids, and carried multiple AMR genes that corresponded with phenotypic AMR profiles. Conclusion Our study revealed the co-occurrence of ISEcp1-blaCTX-M-15 and multiple AMR genes on chromosomal insertions in E. cloacae and E. coli, suggesting that ISEcp1 may be responsible for the transposition of diverse AMR genes from plasmids to chromosomes. Stable retention of such insertions in chromosomes may facilitate the successful propagation of MDR clones among these Enterobacteriaceae species.

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PENGARUH EKSTRAK ETANOL DAUN JAMBU AIR (SYZYGIUM AQUEUM) TERHADAP BAKTERI ISOLAT KLINIS

Jurnal Penelitian Pendidikan IPA ◽

10.29303/jppipa.v1i2.16 ◽

2015 ◽

Vol 1 (2) ◽

Author(s):

Titi Hariyati ◽

Dwi Soelistya Dyah Jekti ◽

Yayuk Andayani

Keyword(s):

Ethanol Extract ◽

Clinical Isolates ◽

E Coli ◽

Randomized Design ◽

Inhibition Concentration ◽

The Family ◽

Ethanol Extracts ◽

Guava Leaves ◽

Guava Leaf

Syzygium aqueum plant of the family Myrtaceae is native of Malaysia and Indonesia and is known as the water rose. The active compound is useful as an antibacterial. This study aimed to determine the effects of ethanol extracts of guava leaves (S. aqueum) as an antimicrobial against clinical isolates bacteria in vitro. The design used in experiment was a Completely Randomized Design (CRD). Data were analyzed using the Kruskal-Wallis test. Results of statistical analysis using SPSS 20 for windows indicated that the ethanol extract of guava leaves has a significant (P<0,05) effect in inhibiting the growth of clinical isolates bacteria. MIC (Minimum Inhibition Concentration) of ethanol extracts for each bacterium can not be determined because the guava leaf extract was very dark. The MBC (Minimum Bacterisidal Concentration) of ethanol extract of guava leaf for both S. aureus and S. dysenteriae was 20%. The MBC of the extract for E. coli, S. thypi, V. cholerae was 25%, where as for B. cereus was at concentration of 50%. It can be concluded that guava leaf has highly potential as a source of antimicrobial agent.Keywords:Antibacteria, Guava Leaf, Clinical Isolates Bacteria, Ethanol Extract

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Molecular cloning, expression and characterization of Bmserpin-2 gene from Bombyx mori.

Acta Biochimica Polonica ◽

10.18388/abp.2009_2501 ◽

2009 ◽

Vol 56 (4) ◽

Cited By ~ 10

Author(s):

Ye Pan ◽

Hengchuan Xia ◽

Peng Lü ◽

KePing Chen ◽

Qin Yao ◽

...

Keyword(s):

Bombyx Mori ◽

Developmental Stages ◽

Pcr Analysis ◽

Post Inoculation ◽

Amino Acid Residues ◽

Gene Encoding ◽

Reading Frame ◽

E Coli ◽

Real Time Quantitative Pcr ◽

Localization Analysis

Serpins are a broadly distributed family of protease inhibitors. In this study, the gene encoding Bombyx mori serpin-2 (Bmserpin-2) was cloned and expressed in E. coli. The Bmserpin-2 cDNA contains a 1125 bp open reading frame (ORF). The deduced protein has 374 amino-acid residues, contains a conserved SERPIN domain and shares extensive homology with other invertebrate serpins. RT-PCR analysis showed that Bmserpin-2 was expressed in all developmental stages of B. mori larvae and various larval tissues. Subcellular localization analysis indicated that Bmserpin-2 protein was located in the cytoplasm. Interestingly, real-time quantitative PCR revealed that the expression of Bmserpin-2 in the midgut of susceptible B. mori strain 306 significantly increased at 72 hours post inoculation (hpi) when infected with BmNPV. However, there was no significant increase of the Bmserpin-2 expression in resistant strain NB infected with BmNPV. Thus, our data indicates that Bmserpin-2 may be involved in B. mori antiviral response.

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