Characterization of the drug resistance plasmid R2418: restriction map and role of insertion and deletion in its evolution

1996 ◽  
Vol 42 (1) ◽  
pp. 12-18 ◽  
Author(s):  
Mohamed Guessouss ◽  
Kamel Ben-Mahrez ◽  
Cherifa Belhadj ◽  
Omrane Belhadj
Keyword(s):  
Escherichia Coli ◽  
Donor Cell ◽  
Streptomycin Resistance ◽  
Conjugal Transfer ◽  
Conjugative Plasmid ◽  
Restriction Map ◽  
Insertion And Deletion ◽  
Endonuclease Mapping

Escherichia coli 2418 strain is resistant to β-lactam antibiotics (ampicillin, carbenicillin, and cephalothin), streptomycin, tetracycline, kanamycin, and chloramphenicol. This strain contains at least two conjugative plasmids (R2418 and R2418S) encoding resistance to β-lactam antibiotics and resistance to both β-lactam antibiotics and streptomycin, respectively. Restriction endonuclease mapping of plasmid DNAs indicates that the plasmid R2418S has evolved from R2418 DNA by the insertion of 2.5-kb DNA between BamHI and PvuII sites, and deletion of 0.5-kb DNA within the EcoRI–EcoRV region. The 2.5-kb DNA insert is responsible for streptomycin resistance. This evolution is also associated with a reduction in the efficiency of conjugal transfer for the plasmid R2418S. The conjugal transfer of streptomycin resistance occurs only through the coresidence of the conjugative plasmid R2418 or R2418S in the donor cell. In accordance with the hypothesis that the Smr determinant is due to a putative transposon, plasmid-free transconjugants resistant to streptomycin only were isolated. Southern blot analysis of HindIII chromosomal digests extracted from these transconjugants shows that the Smr determinant is inserted into different sites in chromosomal DNA.Key words: Escherichia coli, antibiotic resistance, conjugation, transformation, plasmid, transposon, restriction map.

scholarly journals Characterization of a Dye-Decolorizing Peroxidase from Irpex lacteus Expressed in Escherichia coli: An Enzyme with Wide Substrate Specificity Able to Transform Lignosulfonates

2021 ◽  
Vol 7 (5) ◽  
pp. 325
Author(s):  
Laura Isabel de de Eugenio ◽  
Rosa Peces-Pérez ◽  
Dolores Linde ◽  
Alicia Prieto ◽  
Jorge Barriuso ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Inclusion Bodies ◽  
Veratryl Alcohol ◽  
Dye Decolorization ◽  
Irpex Lacteus ◽  
Type D ◽  
Lignin Peroxidases

A dye-decolorizing peroxidase (DyP) from Irpex lacteus was cloned and heterologously expressed as inclusion bodies in Escherichia coli. The protein was purified in one chromatographic step after its in vitro activation. It was active on ABTS, 2,6-dimethoxyphenol (DMP), and anthraquinoid and azo dyes as reported for other fungal DyPs, but it was also able to oxidize Mn2+ (as manganese peroxidases and versatile peroxidases) and veratryl alcohol (VA) (as lignin peroxidases and versatile peroxidases). This corroborated that I. lacteus DyPs are the only enzymes able to oxidize high redox potential dyes, VA and Mn+2. Phylogenetic analysis grouped this enzyme with other type D-DyPs from basidiomycetes. In addition to its interest for dye decolorization, the results of the transformation of softwood and hardwood lignosulfonates suggest a putative biological role of this enzyme in the degradation of phenolic lignin.

scholarly journals Characterization of Epidemic IncI1-Iγ Plasmids Harboring Ambler Class A and C Genes in Escherichia coli and Salmonella enterica from Animals and Humans

2015 ◽  
Vol 59 (9) ◽  
pp. 5357-5365 ◽  
Author(s):  
Hilde Smith ◽  
Alex Bossers ◽  
Frank Harders ◽  
Guanghui Wu ◽  
Neil Woodford ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Salmonella Enterica ◽  
Phylogenetic Trees ◽  
Functional Study ◽  
Content Type ◽  
Gene Associations ◽  
Genes Encoding ◽  
Marked Resistance

ABSTRACTThe aim of the study was to identify the plasmid-encoded factors contributing to the emergence and spread of epidemic IncI1-Iγ plasmids obtained fromEscherichia coliandSalmonella entericaisolates from animal and human reservoirs. For this, 251 IncI1-Iγ plasmids carrying various extended-spectrum β-lactamase (ESBL) or AmpC β-lactamase genes were compared using plasmid multilocus sequence typing (pMLST). Thirty-two of these plasmids belonging to different pMLST types were sequenced using Roche 454 and Illumina platforms. Epidemic IncI1-Iγ plasmids could be assigned to various dominant clades, whereas rarely detected plasmids clustered together as a distinct clade. Similar phylogenetic trees were obtained using only the plasmid backbone sequences, showing that the differences observed between the plasmids belonging to distinct clades resulted mainly from differences between their backbone sequences. Plasmids belonging to the various clades differed particularly in the presence/absence of genes encoding partitioning and addiction systems, which contribute to stable inheritance during cell division and plasmid maintenance. Despite this, plasmids belonging to the various phylogenetic clades also showed marked resistance gene associations, indicating the circulation of successful plasmid-gene combinations. The variation intraYandexcAgenes found in IncI1-Iγ plasmids is conserved within pMLST sequence types and plays a role in incompatibility, although functional study is needed to elucidate the role of these genes in plasmid epidemiology.

scholarly journals Molecular Characterization of Commensal Escherichia coli Adapted to Different Compartments of the Porcine Gastrointestinal Tract

2012 ◽  
Vol 78 (19) ◽  
pp. 6799-6803 ◽  
Author(s):  
Sam Abraham ◽  
David M. Gordon ◽  
James Chin ◽  
Huub J. M. Brouwers ◽  
Peter Njuguna ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Gastrointestinal Tract ◽  
Random Amplified Polymorphic Dna ◽  
Content Type ◽  
E Coli ◽  
Plasmid Replicon ◽  
Different Strains ◽  
Different Characteristics

ABSTRACTThe role ofEscherichia colias a pathogen has been the focus of considerable study, while much less is known about it as a commensal and how it adapts to and colonizes different environmental niches within the mammalian gut. In this study, we characterizeEscherichia coliorganisms (n= 146) isolated from different regions of the intestinal tracts of eight pigs (dueodenum, ileum, colon, and feces). The isolates were typed using the method of random amplified polymorphic DNA (RAPD) and screened for the presence of bacteriocin genes and plasmid replicon types. Molecular analysis of variance using the RAPD data showed thatE. coliisolates are nonrandomly distributed among different gut regions, and that gut region accounted for 25% (P< 0.001) of the observed variation among strains. Bacteriocin screening revealed that a bacteriocin gene was detected in 45% of the isolates, with 43% carrying colicin genes and 3% carrying microcin genes. Of the bacteriocins observed (H47, E3, E1, E2, E7, Ia/Ib, and B/M), the frequency with which they were detected varied with respect to gut region for the colicins E2, E7, Ia/Ib, and B/M. The plasmid replicon typing gave rise to 25 profiles from the 13 Inc types detected. Inc F types were detected most frequently, followed by Inc HI1 and N types. Of the Inc types detected, 7 were nonrandomly distributed among isolates from the different regions of the gut. The results of this study indicate that not only may the different regions of the gastrointestinal tract harbor different strains ofE. colibut also that strains from different regions have different characteristics.

Expression and characterization of the 42 kDa chitinase of the biocontrol fungusMetarhizium anisopliaeinEscherichia coli

2003 ◽  
Vol 49 (11) ◽  
pp. 723-726 ◽  
Author(s):  
César Milton Baratto ◽  
Marcia Vanusa da Silva ◽  
Lucélia Santi ◽  
Luciane Passaglia ◽  
Irene Silveira Schrank ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Recombinant Protein ◽  
Metarhizium Anisopliae ◽  
Entomopathogenic Fungus ◽  
Expression Vector ◽  
Hydrolytic Enzymes ◽  
Active Protein ◽  
Chitinase Genes

Albeit Metarhizium anisopliae is the best-characterized entomopathogenic fungus, the role of some hydrolytic enzymes during host cuticle penetration has not yet been established. Three chitinase genes (chit1, chi2, chi3) from Metarhizium have already been isolated. To characterize the chitinase coded by the chit1 gene, we expressed the active protein (CHIT42) in Escherichia coli using a T7-based promoter expression vector. The recombinant protein, CHIT42, is active against glycol chitin and synthetic N-acetylglucosamine (GlcNAc) dimer and tetramer substrates. These activities suggest that the recombinant CHIT42 acts as an endochitinase.Key words: Metarhizium anisopliae, chitinases, chit genes, recombinant protein, enthomopathogenic fungi.

scholarly journals Kinetic characterization of the Escherichia coli oligopeptidase A (OpdA) and the role of the Tyr607 residue

2010 ◽  
Vol 500 (2) ◽  
pp. 131-136 ◽  
Author(s):  
Ricardo Z. Lorenzon ◽  
Carlos E.L. Cunha ◽  
Marcelo F. Marcondes ◽  
Maurício F.M. Machado ◽  
Maria A. Juliano ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Kinetic Characterization

scholarly journals Polyamine Transport and Role of potE in Response to Osmotic Stress in Escherichia coli

2000 ◽  
Vol 182 (21) ◽  
pp. 6247-6249 ◽  
Author(s):  
Dirk Schiller ◽  
Daniela Kruse ◽  
Helmut Kneifel ◽  
Reinhard Krämer ◽  
Andreas Burkovski
Keyword(s):  
Escherichia Coli ◽  
Osmotic Stress ◽  
Deletion Mutant ◽  
Transport Processes ◽  
Hyperosmotic Shock ◽  
Physiological Conditions ◽  
Polyamine Transport

ABSTRACT When transport of polyamines in Escherichia coli was examined, putrescine excretion was observed under two different physiological conditions: (i) strictly correlated to growth and (ii) following a hyperosmotic shock. Spermidine was not excreted. Characterization of a deletion mutant showed that PotE is not involved in these transport processes.

scholarly journals The plasmid system ofEscherichia colistrain UR12644: Identification and molecular characteristics of transposons involved in the generation of endogenous R-plasmids

1979 ◽  
Vol 34 (3) ◽  
pp. 287-301 ◽  
Author(s):  
F. Schöffl ◽  
A. Pühler
Keyword(s):  
Escherichia Coli ◽  
Molecular Characteristics ◽  
Multiple Drug ◽  
Restriction Map ◽  
Drug Resistant ◽  
Cleavage Sites ◽  
A Value ◽  
Multiple Drug Resistant ◽  
R Plasmids

SUMMARYTwo spontaneously formed R-plasmids (pFS401 and pFS402) originating from the multiple drug-resistantEscherichia colistrain UR12644 were found to carry transposable drug-resistance elements. Incompatibility between these two plasmids was used to select for transposition. An ampicillin transposon (Tn1781) residing on pFS401 and a tetracycline transposon (Tn1771) present on pFS402 were independently translocated to the endogenous RTF-plasmid pFS2. Molecular weight determinations of pFS2::Tn1781(Ap) and pFS2::Tn1771(Tc) revealed a value of 2·9 Mdal for Tn1781 and 7·1 Mdal for Tn1771. The arrangement of 3PstI and 1BamHI restriction endonuclease sites was found to be characteristic for the ampicillin transposon whereas the restriction map of Tn1771 features a nearly symmetrical location of 3EcoRI cleavage sites, two of them close to the termini and one in the middle of the transposon. A model is presented suggesting the existence of repetitive DNA-segments at these positions which represent the structural preconditions for the genetic properties of Tn1771. The role of a cryptic plasmid involved in the generation of the endogenous R-plasmids pFS401 and pFS402 is discussed.

scholarly journals Evolution of Microcin V and Colicin Ia Plasmids in Escherichia coli

2007 ◽  
Vol 189 (19) ◽  
pp. 7045-7052 ◽  
Author(s):  
Anne Jeziorowski ◽  
David M. Gordon
Keyword(s):  
Escherichia Coli ◽  
Conjugative Plasmid ◽  
Host Strain ◽  
Nucleotide Variation ◽  
Strain Characterization ◽  
Fitness Advantage ◽  
Genotypic Characterization ◽  
Survey Results ◽  
Colicin Ia

ABSTRACT Survey results and genotypic characterization of Escherichia coli strains demonstrate that the bacteriocins colicin Ia and microcin V coassociate in a strain more often than would be expected by chance. When these two bacteriocins co-occur, they are encoded on the same conjugative plasmid. Plasmids encoding colicin Ia and microcin V are nonrandomly distributed with respect to the genomic background of the host strain. Characterization of microcin V and colicin Ia nucleotide variation, together with the backbone of plasmids encoding these bacteriocins, indicates that the association has evolved on multiple occasions and involves the movement of the microcin V operon, together with the genes iroNEDCB and iss, onto a nonrandom subset of colicin Ia plasmids. The fitness advantage conferred on cells encoding both colicin Ia and microcin V has yet to be determined.

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