scholarly journals Transposition of IS1397 in the FamilyEnterobacteriaceae and First Characterization of ISKpn1, a New Insertion Sequence Associated withKlebsiella pneumoniae Palindromic Units

2001 ◽  
Vol 183 (15) ◽  
pp. 4395-4404 ◽  
Author(s):  
Caroline Wilde ◽  
Sophie Bachellier ◽  
Maurice Hofnung ◽  
Jean-Marie Clément
Keyword(s):  
Escherichia Coli ◽  
Hot Spots ◽  
Sequence Comparison ◽  
Insertion Sequence ◽  
Klebsiella Oxytoca ◽  
Insertion Sequences ◽  
Serovar Typhimurium ◽  
Intergenic Regions ◽  
First Time

ABSTRACT IS1397 and ISKpn1 are IS3family members which are specifically inserted into the loop of palindromic units (PUs). IS1397 is shown to transpose into PUs with sequences close or identical to the Escherichia coli consensus, even in other enterobacteria (Salmonella enterica serovar Typhimurium, Klebsiella pneumoniae, and Klebsiella oxytoca). Moreover, we show that homologous intergenic regions containing PUs constitute IS1397 transpositional hot spots, despite bacterial interspersed mosaic element structures that differ among the three species. ISKpn1, described here for the first time, is specific for PUs from K. pneumoniae, in which we discovered it. A sequence comparison between the two insertion sequences allowed us to define a motif possibly accounting for their specificity.

scholarly journals First Characterization of CTX-M-15-Producing Escherichia coli Strains Belonging to Sequence Type (ST) 410, ST224, and ST1284 from Commercial Swine in South America

2016 ◽  
Vol 60 (4) ◽  
pp. 2505-2508 ◽  
Author(s):  
Ketrin C. Silva ◽  
Marina Moreno ◽  
Carlos Cabrera ◽  
Beny Spira ◽  
Louise Cerdeira ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
South America ◽  
Insertion Sequence ◽  
Sequence Type ◽  
Content Type ◽  
First Time ◽  
Genetic Context ◽  
New Reservoir

ABSTRACTWe report for the first time the isolation of CTX-M-15-producingEscherichia colistrains belonging to sequence type (ST) 410, ST224, and ST1284 in commercial swine in Brazil. TheblaCTX-M-15gene was located on F-::A9::B1 and C1::A9::B1 IncF-type plasmids, surrounded by a new genetic context comprising the IS26insertion sequence truncated with the ISEcp1element upstream ofblaCTX-M-15. These results reveal that commercial swine have become a new reservoir of CTX-M-15-producing bacteria in South America.

scholarly journals Characterization of the IS200/IS605 Insertion Sequence Family in Halanaerobium Hydrogeniformans

Genes ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 484
Author(s):  
Michael Sadler ◽  
Melanie R. Mormile ◽  
Ronald L. Frank
Keyword(s):  
Insertion Sequence ◽  
Open Reading Frames ◽  
Insertion Sequences ◽  
Genome Plasticity ◽  
Mobile Dna ◽  
Dna Elements ◽  
Left And Right ◽  
Evolutionary Role ◽  
Reading Frames

Mobile DNA elements play a significant evolutionary role by promoting genome plasticity. Insertion sequences are the smallest prokaryotic transposable elements. They are highly diverse elements, and the ability to accurately identify, annotate, and infer the full genomic impact of insertion sequences is lacking. Halanaerobium hydrogeniformans is a haloalkaliphilic bacterium with an abnormally high number of insertion sequences. One family, IS200/IS605, showed several interesting features distinct from other elements in this genome. Twenty-three loci harbor elements of this family in varying stages of decay, from nearly intact to an ends-only sequence. The loci were characterized with respect to two divergent open reading frames (ORF), tnpA and tnpB, and left and right ends of the elements. The tnpB ORF contains two nearly identical insert sequences that suggest recombination between tnpB ORF is occurring. From these results, insertion sequence activity can be inferred, including transposition capability and element interaction.

scholarly journals Resistance Profiling and Molecular Characterization of Extended-Spectrum/Plasmid-Mediated AmpC β-Lactamase-Producing Escherichia coli Isolated from Healthy Broiler Chickens in South Korea

2020 ◽  
Vol 8 (9) ◽  
pp. 1434 ◽  
Author(s):  
Hyun-Ju Song ◽  
Dong Chan Moon ◽  
Abraham Fikru Mechesso ◽  
Hee Young Kang ◽  
Mi Hyun Kim ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Phylogenetic Analysis ◽  
Resistance Gene ◽  
Broiler Chickens ◽  
Human Consumption ◽  
E Coli ◽  
Extended Spectrum ◽  
First Time ◽  
Pfge Profiles

We aimed to identify and characterize extended-spectrum β-lactamase (ESBL)-and/or plasmid-mediated AmpC β-lactamase (pAmpC)-producing Escherichia coli isolated from healthy broiler chickens slaughtered for human consumption in Korea. A total of 332 E. coli isolates were identified from 339 cloacal swabs in 2019. More than 90% of the isolates were resistant to multiple antimicrobials. ESBL/pAmpC-production was noted in 14% (46/332) of the isolates. Six of the CTX-M-β-lactamase-producing isolates were found to co-harbor at least one plasmid-mediated quinolone resistance gene. We observed the co-existence of blaCMY-2 and mcr-1 genes in the same isolate for the first time in Korea. Phylogenetic analysis demonstrated that the majority of blaCMY-2-carrying isolates belonged to subgroup D. Conjugation confirmed the transferability of blaCTX-M and blaCMY-2 genes, as well as non-β-lactam resistance traits from 60.9% (28/46) of the ESBL/pAmpC-producing isolates to a recipient E. coli J53. The ISECP, IS903, and orf477 elements were detected in the upstream or downstream regions. The blaCTX-M and blaCMY-2 genes mainly belonged to the IncI1, IncHI2, and/or IncFII plasmids. Additionally, the majority of ESBL/pAmpC-producing isolates exhibited heterogeneous PFGE profiles. This study showed that healthy chickens act as reservoirs of ESBL/pAmpC-producing E. coli that can potentially be transmitted to humans.

Cloning, Expression and Characterization of a Monooxygenase P450BM3 from Bacillus megaterium ALA2

2012 ◽  
Vol 518-523 ◽  
pp. 5533-5538
Author(s):  
Ting Wang ◽  
Liang Liang Wang ◽  
Xun Li
Keyword(s):  
Escherichia Coli ◽  
Cytochrome P450 ◽  
Linoleic Acid ◽  
Bacillus Megaterium ◽  
Cytochrome P450 Monooxygenases ◽  
P450 Monooxygenases ◽  
Nadph Oxidation ◽  
First Time ◽  
Optimal Ph

Cytochrome P450 monooxygenases are enzymes which are capable of oxidising saturated and unsaturated substrates. P450BM3 from Bacillus megaterium is one of this family. For the first time, the cyp gene for coding P450BM3 from B. megaterium ALA2 has been cloned and expressed in Escherichia coli. The recombinant enzyme is 120 kDa, containing 1049 aa. The highest activity of purified enzyme is 14.8 U/mg towards palmitic acid by monitoring the NADPH oxidation. The optimal pH and temperature were 9.0 and 40°C. The enzyme has higher activity towards linoleic acid, and 2-Methyl-7-octadecene can also be catalyzed which is a precursor of displar.

scholarly journals Characterization of the Catalytic Activities of the PhoQ Histidine Protein Kinase of Salmonella entericaSerovar Typhimurium

2001 ◽  
Vol 183 (5) ◽  
pp. 1787-1791 ◽  
Author(s):  
Martin Montagne ◽  
Alexandre Martel ◽  
Hervé Le Moual
Keyword(s):  
Escherichia Coli ◽  
Phosphatase Activity ◽  
Divalent Cations ◽  
Histidine Protein Kinase ◽  
Catalytic Activities ◽  
Serovar Typhimurium ◽  
High Concentrations ◽  
Kinetics Of ◽  
Autokinase Activity

ABSTRACT Studies of Escherichia coli membranes that were highly enriched in the Salmonella enterica serovar Typhimurium PhoQ protein showed that the presence of ATP and divalent cations such as Mg2+, Mn2+, Ca2+, or Ba2+ resulted in PhoQ autophosphorylation. However, when Mg2+ or Mn2+was present at concentrations higher than 0.1 mM, the kinetics of PhoQ autophosphorylation were strongly biphasic, with a rapid autophosphorylation phase followed by a slower dephosphorylation phase. A fusion protein lacking the sensory and transmembrane domains retained the autokinase activity but could not be dephosphosphorylated when Mg2+ or Mn2+ was present at high concentrations. The instability of purified [32P]phospho-PhoP in the presence of PhoQ-containing membranes indicated that PhoQ also possesses a phosphatase activity. The PhoQ phosphatase activity was stimulated by increasing the Mg2+ concentration. These data are consistent with a model in which Mg2+ binding to the sensory domain of PhoQ coordinately regulates autokinase and phosphatase activities.

scholarly journals Discovery and characterization of a sulfoquinovose mutarotase using kinetic analysis at equilibrium by exchange spectroscopy

2018 ◽  
Vol 475 (7) ◽  
pp. 1371-1383 ◽  
Author(s):  
Palika Abayakoon ◽  
James P. Lingford ◽  
Yi Jin ◽  
Christopher Bengt ◽  
Gideon J. Davies ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Active Sites ◽  
Glucuronic Acid ◽  
Chemical Exchange ◽  
Sequence Analyses ◽  
Uncharacterized Gene ◽  
Exchange Spectroscopy ◽  
First Time ◽  
Better Than

Bacterial sulfoglycolytic pathways catabolize sulfoquinovose (SQ), or glycosides thereof, to generate a three-carbon metabolite for primary cellular metabolism and a three-carbon sulfonate that is expelled from the cell. Sulfoglycolytic operons encoding an Embden–Meyerhof–Parnas-like or Entner–Doudoroff (ED)-like pathway harbor an uncharacterized gene (yihR in Escherichia coli; PpSQ1_00415 in Pseudomonas putida) that is up-regulated in the presence of SQ, has been annotated as an aldose-1-epimerase and which may encode an SQ mutarotase. Our sequence analyses and structural modeling confirmed that these proteins possess mutarotase-like active sites with conserved catalytic residues. We overexpressed the homolog from the sulfo-ED operon of Herbaspirillum seropedicaea (HsSQM) and used it to demonstrate SQ mutarotase activity for the first time. This was accomplished using nuclear magnetic resonance exchange spectroscopy, a method that allows the chemical exchange of magnetization between the two SQ anomers at equilibrium. HsSQM also catalyzed the mutarotation of various aldohexoses with an equatorial 2-hydroxy group, including d-galactose, d-glucose, d-glucose-6-phosphate (Glc-6-P), and d-glucuronic acid, but not d-mannose. HsSQM displayed only 5-fold selectivity in terms of efficiency (kcat/KM) for SQ versus the glycolysis intermediate Glc-6-P; however, its proficiency [kuncat/(kcat/KM)] for SQ was 17 000-fold better than for Glc-6-P, revealing that HsSQM preferentially stabilizes the SQ transition state.

scholarly journals ENTEROBACTERIA ISOLATED FROM SYNANTHROPIC FLIES (DIPTERA, CALYPTRATAE) IN MEDELLÍN, COLOMBIA

Caldasia ◽  
2015 ◽  
Vol 37 (2) ◽  
pp. 319-332 ◽  
Author(s):  
Isabel Cristina Cadavid-S. ◽  
Eduardo Amat ◽  
Luz Miryam Gomez-Piñerez
Keyword(s):  
Escherichia Coli ◽  
High Risk ◽  
Musca Domestica ◽  
Urban Areas ◽  
New Records ◽  
Risk Index ◽  
Klebsiella Oxytoca ◽  
Moderate Risk ◽  
Enteric Diseases ◽  
First Time

<p>Enterobacteria (Enterobacteriaceae) causing enteric diseases can be carried and dispersed through insects that act as mechanical vectors, especially flies (Insecta: Diptera). In this study, enterobacteria associated with synanthropic flies were isolated and identified; four different urban areas in the municipality of Medellín were surveyed. Thirteen taxa of calyptrate flies belonging to four families were identified and classified according to the Mechanical Vector Risk Index (MVRI) value, which is proposed in this study. Chrysomya megacephala (Fabricius, 1794), Lucilia cuprina (Wiedemann, 1819), Chrysomya albiceps (Wiedemann, 1819), and Musca domestica Linnaeus, 1758 are of high risk; Fannia sp., Atherigona orientalis Schiner, 1868, and Ophyra aenescens (Wiedemann, 1830) of moderate risk; remaining species were classified as low or no risk. Escherichia coli was the most frequent bacterium according to the number of isolations (32%), followed by Klebsiella oxytoca (12%), Pasteurella pneumotropica (11%), and Kluyvera spp. (8%). Raoultella ornithinolitica, Stenotrophomponas maltophilia, and Chryseobacterium menigosepticum were isolated for the first time from flies. Finally, 22 new records of bacteria associated with eight fly species were reported. The results allow us to foresee the existence of a generalist pattern in the interaction between flies and bacteria and indicate that synanthropic flies have a quantifiable potential as vectors of infectious diseases according to the index proposed.</p>

scholarly journals A Complex Insertion Sequence Cluster at a Point of Interaction between the Linear Plasmid SCP1 and the Linear Chromosome of Streptomyces coelicolor A3(2)

2000 ◽  
Vol 182 (11) ◽  
pp. 3104-3110 ◽  
Author(s):  
Masayuki Yamasaki ◽  
Kiyotaka Miyashita ◽  
John Cullum ◽  
Haruyasu Kinashi
Keyword(s):  
Sequence Comparison ◽  
Insertion Sequence ◽  
Streptomyces Coelicolor ◽  
Open Reading Frame ◽  
Linear Plasmid ◽  
Nucleotide Sequence Analysis ◽  
Insertion Sequences ◽  
Linear Chromosome ◽  
Reading Frame ◽  
The Right

ABSTRACT The giant linear plasmid SCP1 can integrate into the central region of the linear chromosome of Streptomyces coelicolor A3(2). Nucleotide sequence analysis around the target site for SCP1 integration in strain M145 identified a total of five copies of four insertion sequences (ISs) in a 6.5-kb DNA stretch. Three of the four (IS468, IS469, and IS470) are new IS elements, and the other is IS466. All of these elements contain one open reading frame which encodes a transposase-like protein. Two copies of IS468 (IS468A and -B) are tandemly aligned at the left end of the cluster. Following these, IS469 and IS466 are located in a tail-to-tail orientation with 69.3% identity to each other. IS470 is located at the right end of the cluster. The activities of IS466 and IS468 were demonstrated by transposition experiments and sequence comparison of several copies, respectively.

Long-Term Experimental Evolution in Escherichia coli. IX. Characterization of Insertion Sequence-Mediated Mutations and Rearrangements

Genetics ◽  
2000 ◽  
Vol 156 (2) ◽  
pp. 477-488
Author(s):  
Dominique Schneider ◽  
Esther Duperchy ◽  
Evelyne Coursange ◽  
Richard E Lenski ◽  
Michel Blot
Keyword(s):  
Escherichia Coli ◽  
Experimental Evolution ◽  
Insertion Sequence ◽  
Term Evolution ◽  
Molecular Events ◽  
Evolution Experiment ◽  
Two Populations ◽  
Escherichia Coli B

Abstract As part of a long-term evolution experiment, two populations of Escherichia coli B adapted to a glucose minimal medium for 10,000 generations. In both populations, multiple IS-associated mutations arose that then went to fixation. We identify the affected genetic loci and characterize the molecular events that produced nine of these mutations. All nine were IS-mediated events, including simple insertions as well as recombination between homologous elements that generated inversions and deletions. Sequencing DNA adjacent to the insertions indicates that the affected genes are involved in central metabolism (knockouts of pykF and nadR), cell wall synthesis (adjacent to the promoter of pbpA-rodA), and ill-defined functions (knockouts of hokB-sokB and yfcU). These genes are candidates for manipulation and competition experiments to determine whether the mutations were beneficial or merely hitchhiked to fixation.

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