scholarly journals Inulin and Galacto-oligosaccharides Increase the Genotoxic Effect of Colibactin Produced by pks+ Escherichia Coli Strains

2020 ◽  
Author(s):  
Manon Oliero ◽  
Annie Calvé ◽  
Gabriela Fragoso ◽  
Thibault Cuisiniere ◽  
Roy Hajjar ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Chromosomal Abnormalities ◽  
Iron Sulfate ◽  
Luciferase Reporter ◽  
Dna Breaks ◽  
E Coli ◽  
Double Strand Dna Breaks ◽  
The Impact ◽  
Double Strand Dna

Abstract Background: Colibactin is a genotoxin that induces double-strand DNA breaks and is produced by Escherichia coli strains harboring the pks island. Human and animal studies have shown that colibactin-producing gut bacteria promote carcinogenesis and enhance the progression of colorectal cancer through cellular senescence and chromosomal abnormalities. In this study, we investigated the impact of prebiotics on the genotoxicity of colibactin-producing E. coli strains Nissle 1917 and NC101. Methods: Bacteria were grown in medium supplemented with 20, 30 and 40 mg/mL of prebiotics inulin or galacto-oligosaccharide, and with or without 5 µM, 25 µM and 125 µM of iron sulfate. Colibactin expression was assessed by luciferase reporter assay for the clbA gene, essential for colibactin production, in E. coli Nissle 1917 and by RT-PCR in E. coli NC101. The human epithelial colorectal adenocarcinoma cell line, Caco-2, was used to assess colibactin-induced megalocytosis by methylene blue binding assay and genotoxicity by γ-H2AX immunofluorescence analysis. Results: Inulin and galacto-oligosaccharide enhanced the expression of clbA in pks+ E. coli. However, the addition of 125 µM of iron sulfate inhibited the expression of clbA triggered by oligosaccharides. In the presence of either oligosaccharide, E. coli NC101 increased dysplasia and double-strand DNA breaks in Caco-2 cells compared to untreated cells. Conclusion: Our results suggest that, in vitro, prebiotic oligosaccharides exacerbate DNA damage induced by colibactin-producing bacteria. Further studies are necessary to establish whether these results are reproducible in vivo.

scholarly journals Oligosaccharides increase the genotoxic effect of colibactin produced by pks+ Escherichia coli strains

BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Manon Oliero ◽  
Annie Calvé ◽  
Gabriela Fragoso ◽  
Thibault Cuisiniere ◽  
Roy Hajjar ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Ferrous Sulfate ◽  
Chromosomal Abnormalities ◽  
Double Strand Breaks ◽  
Luciferase Reporter ◽  
Dna Double Strand Breaks ◽  
Strand Breaks ◽  
E Coli ◽  
The Impact

Abstract Background Colibactin is a genotoxin that induces DNA double-strand breaks that may lead to carcinogenesis and is produced by Escherichia coli strains harboring the pks island. Human and animal studies have shown that colibactin-producing gut bacteria promote carcinogenesis and enhance the progression of colorectal cancer through cellular senescence and chromosomal abnormalities. In this study, we investigated the impact of prebiotics on the genotoxicity of colibactin-producing E. coli strains Nissle 1917 and NC101. Methods Bacteria were grown in medium supplemented with 20, 30 and 40 mg/mL of prebiotics inulin or galacto-oligosaccharide, and with or without 5 μM, 25 μM and 125 μM of ferrous sulfate. Colibactin expression was assessed by luciferase reporter assay for the clbA gene, essential for colibactin production, in E. coli Nissle 1917 and by RT-PCR in E. coli NC101. The human epithelial colorectal adenocarcinoma cell line, Caco-2, was used to assess colibactin-induced megalocytosis by methylene blue binding assay and genotoxicity by γ-H2AX immunofluorescence analysis. Results Inulin and galacto-oligosaccharide enhanced the expression of clbA in pks+ E. coli. However, the addition of 125 μM of ferrous sulfate inhibited the expression of clbA triggered by oligosaccharides. In the presence of either oligosaccharide, E. coli NC101 increased dysplasia and DNA double-strand breaks in Caco-2 cells compared to untreated cells. Conclusion Our results suggest that, in vitro, prebiotic oligosaccharides exacerbate DNA damage induced by colibactin-producing bacteria. Further studies are necessary to establish whether oligosaccharide supplementation may lead to increased colorectal tumorigenesis in animal models colonized with pks+ E. coli.

scholarly journals A42 INULIN PROMOTES POLYPS DEVELOPMENT IN APC MIN/+ MOUSE COLONIZED BY ESCHERICHIA COLI NC101

2021 ◽  
Vol 4 (Supplement_1) ◽  
pp. 271-272
Author(s):  
M Oliero ◽  
T Cuisiniere ◽  
R Hajjar ◽  
G Fragoso ◽  
A Calve ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Escherichia Coli ◽  
Animal Studies ◽  
Chromosomal Abnormalities ◽  
Coli Strain ◽  
Dna Breaks ◽  
E Coli ◽  
Double Strand Dna Breaks ◽  
The Impact

Abstract Background Colibactin is a genotoxin that induces double-strand DNA breaks and is produced by Escherichia coli strains harboring the pks island. Human and animal studies have shown that colibactin-producing gut bacteria promote carcinogenesis and facilitate the progression of colorectal cancer through cellular senescence and chromosomal abnormalities. Aims In this study, we investigated the impact of inulin, a prebiotic able to modulate bacterial metabolism, in a colorectal cancer model, ApcMin/+mice, colonized by colibactin-producing E. coli strain NC101. Material & methods Apc Min/+ mice were subjected to oral gavage with PBS (control) or 108 cfu of E. coli NC101 after a week of receiving a 2% dextran sulfate sodium solution in drinking water. Mice were fed a diet supplemented with 10% cellulose (control) or 10% inulin for 4 weeks. During necropsy, the number of polyps in the duodenum, jejunum, ileum, and colon was counted. Tumors in the colon were graded and the erythroid parameters were measured. Results We showed that the inulin diet increased the number of polyps in the ileum compared to cellulose. Moreover, mice colonized with E. coli NC101 and on the inulin diet presented severe anemia associated with an increasing number of polyps in the duodenum, jejunum, and ileum compared to mice supplemented with cellulose. Conclusions Our results suggest that, in vivo, inulin promotes polyp development in the small intestine of ApcMin/+ mice colonized by pks+ E. coli strain NC101. Funding Agencies CIHRNSERC

scholarly journals In VivoTransmission of an IncA/C Plasmid in Escherichia coli Depends on Tetracycline Concentration, and Acquisition of the Plasmid Results in a Variable Cost of Fitness

2015 ◽  
Vol 81 (10) ◽  
pp. 3561-3570 ◽  
Author(s):  
Timothy J. Johnson ◽  
Randall S. Singer ◽  
Richard E. Isaacson ◽  
Jessica L. Danzeisen ◽  
Kevin Lang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
High Dose ◽  
Broad Host Range ◽  
Antibiotic Administration ◽  
Dose Administration ◽  
Content Type ◽  
E Coli ◽  
The Impact ◽  
Selection Of

ABSTRACTIncA/C plasmids are broad-host-range plasmids enabling multidrug resistance that have emerged worldwide among bacterial pathogens of humans and animals. Although antibiotic usage is suspected to be a driving force in the emergence of such strains, few studies have examined the impact of different types of antibiotic administration on the selection of plasmid-containing multidrug resistant isolates. In this study, chlortetracycline treatment at different concentrations in pig feed was examined for its impact on selection and dissemination of an IncA/C plasmid introduced orally via a commensalEscherichia colihost. Continuous low-dose administration of chlortetracycline at 50 g per ton had no observable impact on the proportions of IncA/C plasmid-containingE. colifrom pig feces over the course of 35 days. In contrast, high-dose administration of chlortetracycline at 350 g per ton significantly increased IncA/C plasmid-containingE. coliin pig feces (P< 0.001) and increased movement of the IncA/C plasmid to other indigenousE. colihosts. There was no evidence of conjugal transfer of the IncA/C plasmid to bacterial species other thanE. coli.In vitrocompetition assays demonstrated that bacterial host background substantially impacted the cost of IncA/C plasmid carriage inE. coliandSalmonella.In vitrotransfer and selection experiments demonstrated that tetracycline at 32 μg/ml was necessary to enhance IncA/C plasmid conjugative transfer, while subinhibitory concentrations of tetracyclinein vitrostrongly selected for IncA/C plasmid-containingE. coli. Together, these experiments improve our knowledge on the impact of differing concentrations of tetracycline on the selection of IncA/C-type plasmids.

Escherichia coli and colorectal cancer: Unfolding the enigmatic relationship

2021 ◽  
Vol 22 ◽  
Author(s):  
Rogayeh Nouri ◽  
Alka Hasani ◽  
Kourosh Masnadi Shirazi ◽  
Mohammad Reza Aliand ◽  
Bita Sepehri ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Escherichia Coli ◽  
Mammalian Cells ◽  
Chromosomal Rearrangements ◽  
Current Evidence ◽  
Dna Breaks ◽  
Colon Cells ◽  
E Coli ◽  
Dna Mismatch ◽  
Double Strand Dna Breaks

: Colorectal cancer (CRC) is one of the deadliest cancers in the world. Specific strains of intestinal Escherichia coli (E. coli) may influence the initiation and development of CRC by exploiting virulence factors and inflammatory pathways. Mucosa-associated E. coli strains are more prevalent in CRC biopsies in comparison to healthy controls. Moreover, these strains can survive and replicate within macrophages and induce a pro-inflammatory response. Chronic exposure to inflammatory mediators can lead to increased cell proliferation and cancer. Production of colobactin toxin by the majority of mucosa-associated E. coli isolated from CRC patients is another notable finding. Colibactin-producing E. coli strains, in particular, induce double-strand DNA breaks, stop the cell cycle, involve in chromosomal rearrangements of mammalian cells and are implicated in carcinogenic effects in animal models. Moreover, some enteropathogenic E. coli (EPEC) strains are able to survive and replicate in colon cells as chronic intracellular pathogens and may promote susceptibility to CRC by downregulation of DNA Mismatch Repair (MMR) proteins. In this review, we discuss current evidence and focus on the mechanisms by which E. coli can influence the development of CRC.

scholarly journals Lysine Acetylation Regulates Alanyl-tRNA Synthetase Activity in Escherichia coli

Genes ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 473 ◽  
Author(s):  
Takuya Umehara ◽  
Saori Kosono ◽  
Dieter Söll ◽  
Koji Tamura
Keyword(s):  
Escherichia Coli ◽  
Trna Synthetase ◽  
Synthetase Activity ◽  
Lysine Acetylation ◽  
Trna Synthetases ◽  
E Coli ◽  
Domains Of Life ◽  
The Impact

Protein lysine acetylation is a widely conserved posttranslational modification in all three domains of life. Lysine acetylation frequently occurs in aminoacyl-tRNA synthetases (aaRSs) from many organisms. In this study, we determined the impact of the naturally occurring acetylation at lysine-73 (K73) in Escherichia coli class II alanyl-tRNA synthetase (AlaRS) on its alanylation activity. We prepared an AlaRS K73Ac variant in which Nε-acetyl-l-lysine was incorporated at position 73 using an expanded genetic code system in E. coli. The AlaRS K73Ac variant showed low activity compared to the AlaRS wild type (WT). Nicotinamide treatment or CobB-deletion in an E. coli led to elevated acetylation levels of AlaRS K73Ac and strongly reduced alanylation activities. We assumed that alanylation by AlaRS is affected by K73 acetylation, and the modification is sensitive to CobB deacetylase in vivo. We also showed that E. coli expresses two CobB isoforms (CobB-L and CobB-S) in vivo. CobB-S displayed the deacetylase activity of the AlaRS K73Ac variant in vitro. Our results imply a potential regulatory role for lysine acetylation in controlling the activity of aaRSs and protein synthesis.

scholarly journals Escherichia coli Probiotic Strain ED1a in Pigs Has a Limited Impact on the Gut Carriage of Extended-Spectrum-β-Lactamase-Producing E. coli

2016 ◽  
Vol 61 (1) ◽  
Author(s):  
G. Mourand ◽  
F. Paboeuf ◽  
M. A. Fleury ◽  
E. Jouy ◽  
S. Bougeard ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Probiotic Strain ◽  
Fecal Excretion ◽  
Experimental Conditions ◽  
Content Type ◽  
E Coli ◽  
Extended Spectrum ◽  
Probiotic Treatment ◽  
The Impact

ABSTRACT Four trials were conducted to evaluate the impact of Escherichia coli probiotic strain ED1a administration to pigs on the gut carriage or survival in manure of extended-spectrum-β-lactamase-producing E. coli. Groups of pigs were orally inoculated with strain E. coli M63 carrying the bla CTX-M-1 gene (n = 84) or used as a control (n = 26). In the first two trials, 24 of 40 E. coli M63-inoculated pigs were given E. coli ED1a orally for 6 days starting 8 days after oral inoculation. In the third trial, 10 E. coli M63-inoculated pigs were given either E. coli ED1a or probiotic E. coli Nissle 1917 for 5 days. In the fourth trial, E. coli ED1a was given to a sow and its 12 piglets, and these 12 piglets plus 12 piglets that had not received E. coli ED1a were then inoculated with E. coli M63. Fecal shedding of cefotaxime-resistant Enterobacteriaceae (CTX-RE) was studied by culture, and bla CTX-M-1 genes were quantified by PCR. The persistence of CTX-RE in manure samples from inoculated pigs or manure samples inoculated in vitro with E. coli M63 with or without probiotics was studied. The results showed that E. coli M63 and ED1a were good gut colonizers. The reduction in the level of fecal excretion of CTX-RE in E. coli ED1a-treated pigs compared to that in nontreated pigs was usually less than 1 log10 CFU and was mainly observed during the probiotic administration period. The results obtained with E. coli Nissle 1917 did not differ significantly from those obtained with E. coli ED1a. CTX-RE survival did not differ significantly in manure samples with or without probiotic treatment. In conclusion, under our experimental conditions, E. coli ED1a and E. coli Nissle 1917 could not durably prevent CTX-RE colonization of the pig gut.

scholarly journals The Mechanism of Antimicrobial Peptide MPX against Enterohemorrhagic Escherichia coli in Vitro

2021 ◽  
pp. 18-24
Author(s):  
Ксюєцінь Дзяо ◽  
Ганна Фотіна ◽  
Лей Ванг ◽  
Цзяньхе Ху
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Peptide ◽  
Bactericidal Activity ◽  
Enterohemorrhagic Escherichia Coli ◽  
New Drugs ◽  
Plate Count ◽  
E Coli ◽  
Facultative Anaerobic Bacteria ◽  
The Impact

Escherichia coli is a facultative anaerobic bacteria that exists in the gastrointestinal tract of humans and animals. It can cause diarrhea, enteritis, destruction of the host's intestinal barrier, and intestinal microecological disturbances.  In recent years, due to the abuse of traditional antibiotics, a variety of drug-resistant strains and super bacteria have emerged in an endless stream. Therefore, there is an urgent need to find new alternatives to antibiotics. Antimicrobial peptides are a type of small peptides produced when organisms resist the invasion of foreign microorganisms. They are considered to be the best alternative to antibiotics which has become a research hotspot in recent years. The antimicrobial peptide MPX is extracted from wasp venom and has a good bactericidal effect on many bacteria. To explore the effect of MPX against E. coli. The function of MPX against E. coli was detected by MIC, plate count, propidium iodide, NPN and DiSC3(5) permeability testing, immunofluorescence microscope observation, and the impact of MPX stability by temperature, pH, ion. In this study, the results found that MPX has good antibacterial activity against E. coli, and the minimum inhibitory concentration (MIC) was 31.25 ug/mL. MPX bactericidal kinetics study found that MPX had good bactericidal activity within 6 hours. Bacterial permeability studies have shown that MPX could increase the permeability of bacteria, leading to an increase in the protein content of the bacterial supernatant. In addition, NPN, PI and DiSC3(5) results showed that the fluorescence value was positively correlated with MPX. The stability test of MPX found that salt ions, temperature, pH, etc. have a slight influence on its effect. In addition, scanning electron microscopy results showed that the bacteria became smaller and the contents leaked after the action of MPX. The above results showed that MPX has a good bactericidal activity in vitro, laying the foundation for the development of new drugs for the treatment of bacterial infections.

Quantitation of single- and double-strand DNA breaks in vitro and in vivo

1986 ◽  
Vol 154 (2) ◽  
pp. 485-491 ◽  
Author(s):  
Ron Kohen ◽  
Moshe Szyf ◽  
Mordechai Chevion
Keyword(s):  
Dna Breaks ◽  
Double Strand Dna Breaks ◽  
Double Strand Dna
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