scholarly journals Escherichia coli HS and Enterotoxigenic Escherichia coli Hinder Stress Granule Assembly

2020 ◽  
Vol 9 (1) ◽  
pp. 17
Author(s):  
Felipe Velásquez ◽  
Josefina Marín-Rojas ◽  
Ricardo Soto-Rifo ◽  
Alexia Torres ◽  
Felipe Del Canto ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Host Cell ◽  
Stress Responses ◽  
Bacterial Species ◽  
Coli Strain ◽  
Stress Granule ◽  
Enterotoxigenic Escherichia Coli ◽  
E Coli ◽  
Eif2α Phosphorylation ◽  
Successful Infection

Escherichia coli, one of the most abundant bacterial species in the human gut microbiota, has developed a mutualistic relationship with its host, regulating immunological responses. In contrast, enterotoxigenic E. coli (ETEC), one of the main etiologic agents of diarrheal morbidity and mortality in children under the age of five in developing countries, has developed mechanisms to reduce the immune-activator effect to carry out a successful infection. Following infection, the host cell initiates the shutting-off of protein synthesis and stress granule (SG) assembly. This is mostly mediated by the phosphorylation of translation initiator factor 2α (eIF2α). We therefore evaluated the ability of a non-pathogenic E. coli strain (E. coli HS) and an ETEC strain (ETEC 1766a) to induce stress granule assembly, even in response to exogenous stresses. In this work, we found that infection with E. coli HS or ETEC 1766a prevents SG assembly in Caco-2 cells treated with sodium arsenite (Ars) after infection. We also show that this effect occurs through an eIF2α phosphorylation (eIF2α-P)-dependent mechanism. Understanding how bacteria counters host stress responses will lay the groundwork for new therapeutic strategies to bolster host cell immune defenses against these pathogens.

scholarly journals TleA, a Tsh-Like Autotransporter Identified in a Human Enterotoxigenic Escherichia coli Strain

2015 ◽  
Vol 83 (5) ◽  
pp. 1893-1903 ◽  
Author(s):  
Daniela Gutiérrez ◽  
Mirka Pardo ◽  
David Montero ◽  
Angel Oñate ◽  
Mauricio J. Farfán ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Genomic Library ◽  
Coli Strain ◽  
Enterotoxigenic Escherichia Coli ◽  
Watery Diarrhea ◽  
Temperature Sensitive ◽  
Content Type ◽  
E Coli ◽  
Colonization Factor ◽  
Adhesion Level

EnterotoxigenicEscherichia coli(ETEC), a leading cause of acute diarrhea, colonizes the intestine by means of adhesins. However, 15 to 50% of clinical isolates are negative for known adhesins, making it difficult to identify antigens for broad-coverage vaccines. The ETEC strain 1766a, obtained from a child with watery diarrhea in Chile, harbors the colonization factor CS23 but is negative for other known adhesins. One clone, derived from an ETEC 1766a genomic library (clone G10), did not produce CS23 yet was capable of adhering to Caco-2 cells. The goal of this study was to identify the gene responsible for this capacity. Random transposon-based mutagenesis allowed the identification of a 4,110-bp gene that codes for a homologue of the temperature-sensitive hemagglutinin (Tsh) autotransporter described in avianE. colistrains (97% identity, 90% coverage) and that is called TleA (Tsh-like ETEC autotransporter) herein. An isogenic ETEC 1766a strain with atleAmutation showed an adhesion level similar to that of the wild-type strain, suggesting that the gene does not direct attachment to Caco-2 cells. However, expression oftleAconferred the capacity for adherence to nonadherentE. coliHB101. This effect coincided with the detection of TleA on the surface of nonpermeabilized bacteria, while, conversely, ETEC 1766a seems to secrete most of the produced autotransporter to the medium. On the other hand, TleA was capable of degrading bovine submaxillary mucin and leukocyte surface glycoproteins CD45 and P-selectin glycoprotein ligand 1 (PSGL-1). These results suggest that TleA promotes colonization of the intestinal epithelium and that it may modulate the host immune response.

scholarly journals Overlapping stimulons arising in response to divergent stresses in Escherichia coli

2021 ◽  
Author(s):  
Huijing Wang ◽  
GW McElfresh ◽  
Nishantha Wijesuriya ◽  
Adam Podgorny ◽  
Andrew D Hecht ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Stress Response ◽  
Stress Responses ◽  
Differential Expression Analysis ◽  
Stringent Response ◽  
Coli Strain ◽  
Growth Media ◽  
Overflow Metabolism ◽  
Rna Seq ◽  
E Coli

Cellular responses to stress can cause a similar change in some facets of fitness even if the stresses are different. Lactose as a sole carbon source for Escherichia coli is an established example: too little causes starvation while excessive lactose import causes toxicity as a side-effect. In an E. coli strain that is robust to osmotic and ionic differences in growth media, B REL606, the rate of antibiotic-tolerant persister formation is elevated in both starvation-inducing and toxicity-inducing concentrations of lactose in comparison to less stressful intermediate concentrations. Such similarities between starvation and toxification raise the question of how much the global stress response stimulon differs between them. We hypothesized that a common stress response is conserved between the two conditions, but that a previously shown threshold driving growth rate heterogeneity in a lactose-toxifying medium would reveal that the growing fraction of cells in that medium to be missing key stress responses that curb growth. To test this, we performed RNA-seq in three representative conditions for differential expression analysis. In comparison to nominally unstressed cultures, both stress conditions showed global shifts in gene expression, with informative similarities and differences. Functional analysis of pathways, gene ontology terms, and clusters of orthogonal groups revealed signatures of overflow metabolism, membrane component shifts, and altered cytosolic and periplasmic contents in toxified cultures. Starving cultures showed an increased tendency toward stringent response-like regulatory signatures. Along with other emerging evidence, our results show multiple possible pathways to stress responses, persistence, and possibly other phenotypes. These results suggest a set of overlapping responses that drives emergence of stress-tolerant phenotypes in diverse conditions.

scholarly journals Lineage-Specific Distribution of Insertion Sequence Excision Enhancer in Enterotoxigenic Escherichia coli Isolated from Swine

2013 ◽  
Vol 80 (4) ◽  
pp. 1394-1402 ◽  
Author(s):  
Masahiro Kusumoto ◽  
Dai Fukamizu ◽  
Yoshitoshi Ogura ◽  
Eiji Yoshida ◽  
Fumiko Yamamoto ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Bacterial Species ◽  
Bacterial Genome ◽  
Enterotoxigenic Escherichia Coli ◽  
Content Type ◽  
E Coli ◽  
Genomic Deletions ◽  
Specific Distribution ◽  
Multiple Copies ◽  
Genomic Locations

ABSTRACTInsertion sequences (ISs) are the simplest transposable elements and are widely distributed in bacteria; however, they also play important roles in genome evolution. We recently identified a protein called IS excision enhancer (IEE) in enterohemorrhagicEscherichia coli(EHEC) O157. IEE promotes the excision of IS elements belonging to the IS3family, such as IS629, as well as several other families. IEE-mediated IS excision generates various genomic deletions that lead to the diversification of the bacterial genome. IEE has been found in a broad range of bacterial species; however, among sequencedE. colistrains, IEE is primarily found in EHEC isolates. In this study, we investigated non-EHEC pathogenicE. colistrains isolated from domestic animals and found that IEE is distributed in specific lineages of enterotoxigenicE. coli(ETEC) strains of serotypes O139 or O149 isolated from swine. Theieegene is located within integrative elements that are similar to SpLE1 of EHEC O157. Alliee-positive ETEC lineages also contained multiple copies of IS629, a preferred substrate of IEE, and their genomic locations varied significantly between strains, as observed in O157. These data suggest that IEE may have been transferred among EHEC and ETEC in swine via SpLE1 or SpLE1-like integrative elements. In addition, IS629is actively moving in the ETEC O139 and O149 genomes and, as in EHEC O157, is promoting the diversification of these genomes in combination with IEE.

scholarly journals Optimized expression of Hfq protein increases Escherichia coli growth

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Phuong N. L. VO ◽  
Hyang-Mi LEE ◽  
Jun REN ◽  
Dokyun NA
Keyword(s):  
Escherichia Coli ◽  
Growth Rate ◽  
Stress Responses ◽  
Bacterial Species ◽  
Expression Level ◽  
Rna Seq ◽  
E Coli ◽  
Network Analyses ◽  
Metabolic Genes ◽  
Cell Densities

AbstractEscherichia coli is a widely used platform for metabolic engineering due to its fast growth and well-established engineering techniques. However, there has been a demand for faster-growing E. coli for higher production of desired substances. Here, to increase the growth of E. coli cells, we optimized the expression level of Hfq protein, which plays an essential role in stress responses. Six variants of the hfq gene with a different ribosome binding site sequence and thereby a different expression level were constructed. When the Hfq expression level was optimized in DH5α, its growth rate was increased by 12.1% and its cell density was also increased by 4.5%. RNA-seq and network analyses revealed the upregulation of stress response genes and metabolic genes, which increases the tolerance against pH changes. When the same strategy was applied to five other E. coli strains (BL21 (DE3), JM109, TOP10, W3110, and MG1655), all their growth rates were increased by 18–94% but not all their densities were increased (− 12 − + 32%). In conclusion, the Hfq expression optimization can increase cell growth rate and probably their cell densities as well. Since the hfq gene is highly conserved across bacterial species, the same strategy could be applied to other bacterial species to construct faster-growing strains.

scholarly journals A selC-Associated Genomic Island of the Extraintestinal Avian Pathogenic Escherichia coli Strain BEN2908 Is Involved in Carbohydrate Uptake and Virulence

2006 ◽  
Vol 188 (3) ◽  
pp. 977-987 ◽  
Author(s):  
Iman Chouikha ◽  
Pierre Germon ◽  
Annie Brée ◽  
Philippe Gilot ◽  
Maryvonne Moulin-Schouleur ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Genomic Island ◽  
Bacterial Species ◽  
Coli Strain ◽  
Major Facilitator Superfamily ◽  
Integrase Gene ◽  
E Coli ◽  
Pathogenic Escherichia Coli ◽  
Major Facilitator Superfamily Transporter ◽  
Major Facilitator

ABSTRACT The complete nucleotide sequence and genetic organization of a new genomic island (AGI-3) isolated from the extraintestinal avian pathogenic Escherichia coli strain BEN2908 is reported. This 49,600-bp island is inserted at the selC locus and contains putative mobile genetic elements such as a phage-related integrase gene, transposase genes, and direct repeats. AGI-3 shows a mosaic structure of five modules. Some of these modules are present in other E. coli strains and in other pathogenic bacterial species. The gene cluster aec-35 to aec-37 of module 1 encodes proteins associated with carbohydrates assimilation such as a major facilitator superfamily transporter (Aec-36), a glycosidase (Aec-37), and a putative transcriptional regulator of the LacI family (Aec-35). The aec-35 to aec-37 cluster was found in 11.6% of the tested pathogenic and nonpathogenic E. coli strains. When present, the aec-35 to aec-37 cluster is strongly associated with the selC locus (97%). Deletion of the aec-35-aec-37 region affects the assimilation of seven carbohydrates, decreases the growth rate of the strain in minimal medium containing galacturonate or trehalose, and attenuates the virulence of E. coli BEN2908 for chickens.

scholarly journals A Commensal Gone Bad: Complete Genome Sequence of the Prototypical Enterotoxigenic Escherichia coli Strain H10407

2010 ◽  
Vol 192 (21) ◽  
pp. 5822-5831 ◽  
Author(s):  
Lisa C. Crossman ◽  
Roy R. Chaudhuri ◽  
Scott A. Beatson ◽  
Timothy J. Wells ◽  
Mickael Desvaux ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Genomic Sequence ◽  
Epidemiological Data ◽  
Coli Strain ◽  
Enterotoxigenic Escherichia Coli ◽  
E Coli ◽  
Extraintestinal Disease ◽  
K 12 ◽  
Genetic Context ◽  
Complete Genomic

ABSTRACT In most cases, Escherichia coli exists as a harmless commensal organism, but it may on occasion cause intestinal and/or extraintestinal disease. Enterotoxigenic E. coli (ETEC) is the predominant cause of E. coli-mediated diarrhea in the developing world and is responsible for a significant portion of pediatric deaths. In this study, we determined the complete genomic sequence of E. coli H10407, a prototypical strain of enterotoxigenic E. coli, which reproducibly elicits diarrhea in human volunteer studies. We performed genomic and phylogenetic comparisons with other E. coli strains, revealing that the chromosome is closely related to that of the nonpathogenic commensal strain E. coli HS and to those of the laboratory strains E. coli K-12 and C. Furthermore, these analyses demonstrated that there were no chromosomally encoded factors unique to any sequenced ETEC strains. Comparison of the E. coli H10407 plasmids with those from several ETEC strains revealed that the plasmids had a mosaic structure but that several loci were conserved among ETEC strains. This study provides a genetic context for the vast amount of experimental and epidemiological data that have been published.

scholarly journals CD45RA and CD45RC isoforms expression in weaned pigs vaccinated with non-enterotoxigenic F4ac+ Escherichia coli strain against colibacillosis

2012 ◽  
Vol 47 (No. 1) ◽  
pp. 5-11 ◽  
Author(s):  
F. Božič ◽  
L. Švec ◽  
I. Valpotič
Keyword(s):  
Escherichia Coli ◽  
Lymphocyte Activation ◽  
Surface Expression ◽  
Coli Strain ◽  
Enterotoxigenic Escherichia Coli ◽  
Effective Vaccine ◽  
Spleen Cells ◽  
Weaned Pigs ◽  
Phenotypic Analysis ◽  
E Coli

Since no effective vaccine is available for its immunoprophylaxis, porcine post-weaning diarrhoea (PWD) induced by enterotoxigenic Escherichia coli (ETEC) strains remains an important cause of morbidity. Live attenuated oral vaccines have been suggested to be relatively effective in preventing ETEC-induced PWD in the pigs, but the mechanisms responsible for protection have not been elucidated. In the present study we have investigated the likely impact of oral vaccination of weaned pigs with non-ETEC strain expressing F4ac antigen on CD45RA and CD45RC isoforms expression on the surface of the mesenteric lymph node (MLN) cells and on spleen cells by using one-colour flow cytometry. Additionally, to assess the activation state of T cells in the MLN and spleen of the pigs, surface expression of the lymphocyte activation marker CD25 was analysed. Sham-vaccinated weaned pigs served as controls. Our results of the quantitative phenotypic analysis of isolated lymphocytes showed that the vaccinal E. coli strain induced elevation of both CD25+ and CD45RC+ cells in the spleen, but not MLN, of the vaccinated weaned pigs. This was accompanied by decreased CD45RA expression on spleen cells, suggesting that CD45RA+ spleen cells could develop CD45RC phenotype, probably as a consequence of activation in the vaccinated challenge-infected weaned pigs.

scholarly journals Deletion of FaeG alleviated Enterotoxigenic Escherichia coli F4ac-induced apoptosis in the intestine

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pengpeng Xia ◽  
Yunping Wu ◽  
Siqi Lian ◽  
Guomei Quan ◽  
Yiting Wang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Clinical Symptoms ◽  
Mucosal Damage ◽  
Enterotoxigenic Escherichia Coli ◽  
Intestinal Epithelial ◽  
Antibody Microarray ◽  
E Coli ◽  
Fimbrial Subunit ◽  
Induced Apoptosis ◽  
Weaning Piglets

AbstractEnterotoxigenic Escherichia coli (ETEC) F4ac is a major constraint to the development of the pig industry, which is causing newborn and post-weaning piglets diarrhea. Previous studies proved that FaeG is the major fimbrial subunit of F4ac E. coli and efficient for bacterial adherence and receptor recognition. Here we show that the faeG deletion attenuates both the clinical symptoms of F4ac infection and the F4ac-induced intestinal mucosal damage in piglets. Antibody microarray analysis and the detection of mRNA expression using porcine neonatal jejunal IPEC-J2 cells also determined that the absence of FaeG subunit alleviated the F4ac promoted apoptosis in the intestinal epithelial cells. Thus, targeted depletion of FaeG is still beneficial for the prevention or treatment of F4ac infection.

scholarly journals Regulation of Expression of the TIR-Containing Protein C Gene of the Uropathogenic Escherichia coli Strain CFT073

Pathogens ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 549
Author(s):  
Julia Ittensohn ◽  
Jacqueline Hemberger ◽  
Hannah Griffiths ◽  
Maren Keller ◽  
Simone Albrecht ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Protein C ◽  
Interleukin 1 ◽  
Coli Strain ◽  
Uropathogenic Escherichia Coli ◽  
Reporter Construct ◽  
Regulation Of Expression ◽  
E Coli ◽  
Strain Cft073 ◽  
Myeloid Differentiation Factor

The uropathogenic Escherichia coli strain CFT073 causes kidney abscesses in mice Toll/interleukin-1 receptor domain-containing protein C (TcpC) dependently and the corresponding gene is present in around 40% of E. coli isolates of pyelonephritis patients. It impairs the Toll-like receptor (TLR) signaling chain and the NACHT leucin-rich repeat PYD protein 3 inflammasome (NLRP3) by binding to TLR4 and myeloid differentiation factor 88 as well as to NLRP3 and caspase-1, respectively. Overexpression of the tcpC gene stopped replication of CFT073. Overexpression of several tcpC-truncation constructs revealed a transmembrane region, while its TIR domain induced filamentous bacteria. Based on these observations, we hypothesized that tcpC expression is presumably tightly controlled. We tested two putative promoters designated P1 and P2 located at 5′ of the gene c2397 and 5′ of the tcpC gene (c2398), respectively, which may form an operon. High pH and increasing glucose concentrations stimulated a P2 reporter construct that was considerably stronger than a P1 reporter construct, while increasing FeSO4 concentrations suppressed their activity. Human urine activated P2, demonstrating that tcpC might be induced in the urinary tract of infected patients. We conclude that P2, consisting of a 240 bp region 5′ of the tcpC gene, represents the major regulator of tcpC expression.

scholarly journals Characterization of Escherichia coli Strains Derived from Cow Milk of Subclinical and Clinical Cases of Mastitis

2021 ◽  
Vol 11 (2) ◽  
pp. 541
Author(s):  
Katarzyna Grudlewska-Buda ◽  
Krzysztof Skowron ◽  
Ewa Wałecka-Zacharska ◽  
Natalia Wiktorczyk-Kapischke ◽  
Jarosław Bystroń ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Bacterial Species ◽  
Subclinical Mastitis ◽  
Clinical Mastitis ◽  
Economic Problem ◽  
Cow Milk ◽  
P Value ◽  
Dairy Herds ◽  
E Coli ◽  
Bonferroni Test

Mastitis is a major economic problem in dairy herds, as it might decrease fertility, and negatively affect milk quality and milk yield. Out of over 150 bacterial species responsible for the udder inflammation, Escherichia coli is one of the most notable. This study aimed to assess antimicrobial susceptibility, resistance to dipping agents and biofilm formation of 150 E. coli strains isolated from milk of cows with subclinical and clinical mastitis. The strains came from three dairy herds located in Northern and Central Poland. The statistical analyses were performed with post-hoc Bonferroni test and chi-square test (including Yates correction). The data with a p value of <0.05 were considered significant. We found that the tested strains were mostly sensitive to antimicrobials and dipping agents. It was shown that 37.33% and 4.67% of strains were resistant and moderately resistant to at least one antimicrobial agent, respectively. No extended-spectrum beta-lactamases (ESBL)-producing E. coli were detected. The majority of strains did not possess the ability to form biofilm or formed a weak biofilm. The strong biofilm formers were found only among strains derived from cows with subclinical mastitis. The lowest bacteria number was noted for subclinical mastitis cows’ strains, after stabilization with iodine (3.77 log CFU × cm−2) and chlorhexidine (3.96 log CFU × cm−2) treatment. In the present study, no statistically significant differences in susceptibility to antibiotics and the ability to form biofilm were found among the strains isolated from cows with subclinical and clinical mastitis. Despite this, infections in dairy herds should be monitored. Limiting the spread of bacteria and characterizing the most common etiological factors would allow proper treatment.

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