ROS-based lethality of Caenorhabditis elegans mitochondrial electron transport mutants grown on Escherichia coli siderophore iron release mutants

Caenorhabditis elegans consumes bacteria, which can supply essential vitamins and cofactors, especially for mitochondrial functions that have a bacterial ancestry. Therefore, we screened the Keio Escherichia coli knockout library for mutations that induce the C. elegans hsp-6 mitochondrial damage response gene, and identified 45 E. coli mutations that induce hsp-6::gfp. We tested whether any of these E. coli mutations that stress the C. elegans mitochondrion genetically interact with C. elegans mutations in mitochondrial functions. Surprisingly, 4 E. coli mutations that disrupt the import or removal of iron from the bacterial siderophore enterobactin were lethal in combination with a collection of C. elegans mutations that disrupt particular iron–sulfur proteins of the electron transport chain. Bacterial mutations that fail to synthesize enterobactin are not synthetic lethal with these C. elegans mitochondrial mutants; it is the enterobactin–iron complex that is lethal in combination with the C. elegans mitochondrial mutations. Antioxidants suppress this inviability, suggesting that reactive oxygen species (ROS) are produced by the mutant mitochondria in combination with the bacterial enterobactin–iron complex.

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ROS-based lethality of C. elegans mitochondrial electron transport mutants grown on E. coli siderophore iron release mutants

10.1101/707968 ◽

2019 ◽

Author(s):

J. Amaranath Govindan ◽

Elamparithi Jayamani ◽

Gary Ruvkun

Keyword(s):

Reactive Oxygen Species ◽

Electron Transport ◽

Iron Complex ◽

Oxygen Species ◽

Mitochondrial Mutations ◽

Response Gene ◽

Synthetic Lethal ◽

E Coli ◽

C Elegans ◽

Damage Response

AbstractC. elegans consumes bacteria which can supply essential vitamins and cofactors especially for mitochondrial functions ancestrally related to bacteria. Therefore, we screened the Keio E. coli knockout library for mutations that induce a C. elegans mitochondrial damage response gene. We identified 45 E. coli mutations that induce a the C. elegans hsp-6::gfp response gene. Surprisingly, four of these E. coli mutations that disrupt the import or removal of iron from the bacterial siderophore enterobactin were lethal in combination with C. elegans mutations that disrupt particular iron-sulfur proteins of the electron transport chain. Bacterial mutations that fail to synthesize enterobactin are not synthetic lethal with these C. elegans mitochondrial mutants; it is the enterobactin-iron complex that is lethal in combination with the C. elegans mitochondrial mutations. Antioxidants suppress this inviability, suggesting that reactive oxygen species (ROS) are produced by the mutant mitochondria in combination with the bacterial enterobactin-iron complex.Significance StatementThe animal mitochondrion has a bacterial origin and continues to have a dialogue with the bacterial metabolisms of their microbiome. We identified 45 E. coli gene disruptions that induce a C. elegans mitochondrial damage response gene. Four of these E. coli mutations that disrupt the import or retrieval of iron from the siderophore enterobactin were synthetic lethal with C. elegans mitochondrial mutants. Antioxidants strongly suppressed the inviability of C. elegans mitochondrial mutants grown on the E. coli enterobactin siderophore utilization or import mutants. We hypothesize that reactive oxygen species are produced by C. elegans mitochondrial mutations and that this non-lethal ROS triggers ferric-chelated enterobactin to induce dramatically increased ROS, which leads to lethality.

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Iron Acquisition of Urinary Tract Infection Escherichia coli Involves Pathogenicity in Caenorhabditis elegans

Microorganisms ◽

10.3390/microorganisms9020310 ◽

2021 ◽

Vol 9 (2) ◽

pp. 310

Author(s):

Masayuki Hashimoto ◽

Yi-Fen Ma ◽

Sin-Tian Wang ◽

Chang-Shi Chen ◽

Ching-Hao Teng

Keyword(s):

Escherichia Coli ◽

Urinary Tract ◽

Caenorhabditis Elegans ◽

Large Scale ◽

Iron Acquisition ◽

Infection Model ◽

High Throughput Analysis ◽

E Coli ◽

C Elegans ◽

Tract Infections

Uropathogenic Escherichia coli (UPEC) is a major bacterial pathogen that causes urinary tract infections (UTIs). The mouse is an available UTI model for studying the pathogenicity; however, Caenorhabditis elegans represents as an alternative surrogate host with the capacity for high-throughput analysis. Then, we established a simple assay for a UPEC infection model with C. elegans for large-scale screening. A total of 133 clinically isolated E. coli strains, which included UTI-associated and fecal isolates, were applied to demonstrate the simple pathogenicity assay. From the screening, several virulence factors (VFs) involved with iron acquisition (chuA, fyuA, and irp2) were significantly associated with high pathogenicity. We then evaluated whether the VFs in UPEC were involved in the pathogenicity. Mutants of E. coli UTI89 with defective iron acquisition systems were applied to a solid killing assay with C. elegans. As a result, the survival rate of C. elegans fed with the mutants significantly increased compared to when fed with the parent strain. The results demonstrated, the simple assay with C. elegans was useful as a UPEC infectious model. To our knowledge, this is the first report of the involvement of iron acquisition in the pathogenicity of UPEC in a C. elegans model.

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A Pathoadaptive Deletion in an Enteroaggregative Escherichia coli Outbreak Strain Enhances Virulence in a Caenorhabditis elegans Model

Infection and Immunity ◽

10.1128/iai.00014-10 ◽

2010 ◽

Vol 78 (9) ◽

pp. 4068-4076 ◽

Cited By ~ 11

Author(s):

Jennifer Hwang ◽

Lisa M. Mattei ◽

Laura G. VanArendonk ◽

Philip M. Meneely ◽

Iruka N. Okeke

Keyword(s):

Escherichia Coli ◽

Caenorhabditis Elegans ◽

Epithelial Cells ◽

Genetic Material ◽

Decarboxylase Activity ◽

Multicopy Plasmid ◽

Lysine Decarboxylase ◽

Outbreak Strain ◽

E Coli ◽

C Elegans

ABSTRACT Enteroaggregative Escherichia coli (EAEC) strains are important diarrheal pathogens. EAEC strains are defined by their characteristic stacked-brick pattern of adherence to epithelial cells but show heterogeneous virulence and have different combinations of adhesin and toxin genes. Pathoadaptive deletions in the lysine decarboxylase (cad) genes have been noted among hypervirulent E. coli subtypes of Shigella and enterohemorrhagic E. coli. To test the hypothesis that cad deletions might account for heterogeneity in EAEC virulence, we developed a Caenorhabditis elegans pathogenesis model. Well-characterized EAEC strains were shown to colonize and kill C. elegans, and differences in virulence could be measured quantitatively. Of 49 EAEC strains screened for lysine decarboxylase activity, 3 tested negative. Most notable is isolate 101-1, which was recovered in Japan, from the largest documented EAEC outbreak. EAEC strain 101-1 was unable to decarboxylate lysine in vitro due to deletions in cadA and cadC, which, respectively, encode lysine decarboxylase and a transcriptional activator of the cadAB genes. Strain 101-1 was significantly more lethal to C. elegans than control strain OP50. Lethality was attenuated when the lysine decarboxylase defect was complemented from a multicopy plasmid and in single copy. In addition, restoring lysine decarboxylase function produced derivatives of 101-1 deficient in aggregative adherence to cultured human epithelial cells. Lysine decarboxylase inactivation is pathoadapative in an important EAEC outbreak strain, and deletion of cad genes could produce hypervirulent EAEC lineages in the future. These results suggest that loss, as well as gain, of genetic material can account for heterogeneous virulence among EAEC strains.

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Evaluating the Pathogenic Potential of Environmental Escherichia coli by Using the Caenorhabditis elegans Infection Model

Applied and Environmental Microbiology ◽

10.1128/aem.03501-12 ◽

2013 ◽

Vol 79 (7) ◽

pp. 2435-2445 ◽

Cited By ~ 15

Author(s):

Alexandra Merkx-Jacques ◽

Anja Coors ◽

Roland Brousseau ◽

Luke Masson ◽

Alberto Mazza ◽

...

Keyword(s):

Escherichia Coli ◽

Caenorhabditis Elegans ◽

Virulence Genes ◽

Human Health Risk ◽

Environmental Isolates ◽

Pathogenic Potential ◽

Content Type ◽

E Coli ◽

C Elegans ◽

Infection Assay

ABSTRACTThe detection and abundance ofEscherichia coliin water is used to monitor and mandate the quality of drinking and recreational water. Distinguishing commensal waterborneE. coliisolates from those that cause diarrhea or extraintestinal disease in humans is important for quantifying human health risk. A DNA microarray was used to evaluate the distribution of virulence genes in 148E. colienvironmental isolates from a watershed in eastern Ontario, Canada, and in eight clinical isolates. Their pathogenic potential was evaluated withCaenorhabditis elegans, and the concordance between the bioassay result and the pathotype deduced by genotyping was explored. Isolates identified as potentially pathogenic on the basis of their complement of virulence genes were significantly more likely to be pathogenic toC. elegansthan those determined to be potentially nonpathogenic. A number of isolates that were identified as nonpathogenic on the basis of genotyping were pathogenic in the infection assay, suggesting that genotyping did not capture all potentially pathogenic types. The detection of the adhesin-encoding genessfaD,focA, andfocG, which encode adhesins; ofiroN2, which encodes a siderophore receptor; ofpic, which encodes an autotransporter protein; and ofb1432, which encodes a putative transposase, was significantly associated with pathogenicity in the infection assay. Overall,E. coliisolates predicted to be pathogenic on the basis of genotyping were indeed so in theC. elegansinfection assay. Furthermore, the detection ofC. elegans-infective environmental isolates predicted to be nonpathogenic on the basis of genotyping suggests that there are hitherto-unrecognized virulence factors or combinations thereof that are important in the establishment of infection.

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Adherent-Invasive and Non-Invasive Escherichia coli Isolates Differ in Their Effects on Caenorhabditis elegans’ Lifespan

Microorganisms ◽

10.3390/microorganisms9091823 ◽

2021 ◽

Vol 9 (9) ◽

pp. 1823

Author(s):

Maria Beatriz de Sousa de Sousa Figueiredo ◽

Elizabeth Pradel ◽

Fanny George ◽

Séverine Mahieux ◽

Isabelle Houcke ◽

...

Keyword(s):

Escherichia Coli ◽

Caenorhabditis Elegans ◽

Epithelial Cells ◽

Intestinal Epithelial Cells ◽

Host Bacterium ◽

Soil Nematode ◽

Intestinal Epithelial ◽

Barrier Dysfunction ◽

E Coli ◽

C Elegans

The adherent-invasive Escherichia coli (AIEC) pathotype has been implicated in the pathogenesis of inflammatory bowel diseases in general and in Crohn’s disease (CD) in particular. AIEC strains are primarily characterized by their ability to adhere to and invade intestinal epithelial cells. However, the genetic and phenotypic features of AIEC isolates vary greatly as a function of the strain’s clonality, host factors, and the gut microenvironment. It is thus essential to identify the determinants of AIEC pathogenicity and understand their role in intestinal epithelial barrier dysfunction and inflammation. We reasoned that soil nematode Caenorhabditis elegans (a simple but powerful model of host-bacterium interactions) could be used to study the virulence of AIEC vs. non- AIEC E. coli strains. Indeed, we found that the colonization of C. elegans (strain N2) by E. coli impacted survival in a strain-specific manner. Moreover, the AIEC strains’ ability to invade cells in vitro was linked to the median lifespan in C. elegans (strain PX627). However, neither the E. coli intrinsic invasiveness (i.e., the fact for an individual strain to be characterized as invasive or not) nor AIEC’s virulence levels (i.e., the intensity of invasion, established in % from the infectious inoculum) in intestinal epithelial cells was correlated with C. elegans’ lifespan in the killing assay. Nevertheless, AIEC longevity of C. elegans might be a relevant model for screening anti-adhesion drugs and anti-invasive probiotics.

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Pathogenicity of urinary tract infection Escherichia coli in Caenorhabditis elegans

10.1101/858910 ◽

2019 ◽

Author(s):

Masayuki Hashimoto ◽

Yi-Fen Ma ◽

Sin-Tian Wang ◽

Chang-Shi Chen ◽

Ching-Hao Teng

Keyword(s):

Escherichia Coli ◽

Urinary Tract ◽

Caenorhabditis Elegans ◽

Large Scale ◽

Iron Homeostasis ◽

Iron Acquisition ◽

Infection Model ◽

E Coli ◽

C Elegans ◽

Tract Infections

AbstractUropathogenic Escherichia coli (UPEC) is a major bacterial pathogen that causes urinary tract infections (UTIs). Several virulence factors (VFs) in the bacteria have been associated with the pathogenicity. The mouse is an available UTI model for studying the pathogenicity; however, Caenorhabditis elegans represents as an alternative surrogate host for studying UPEC with the capacity for high-throughput analysis. Therefore, we established a simple assay for a UPEC infection model with C. elegans for large-scale screening. An E. coli culture to be tested and synchronized C. elegans were mixed in 96-well plates, and the pathogenicity was determined by comparison of the turbidity before and after incubation. A total of 133 clinically isolated E. coli strains, which included UTI-associated and fecal isolates, were applied to demonstrate the liquid pathogenicity assay. The E. coli isolates associated with UTIs showed higher pathogenicity in C. elegans than the fecal isolates, suggesting that the simple assay with C. elegans is useful as a UPEC infectious model. From the screening, VFs involved with iron acquisition (chuA, fyuA, and irp2) were significantly associated with high pathogenicity. C. elegans is a heme auxotroph, and iron homeostasis also serves innate immunity in C. elegans. We then evaluated whether the VFs in UPEC were involved in the pathogenicity. Mutants of E. coli UTI89 with defective iron acquisition systems were applied to a solid killing assay with C. elegans. As a result, the survival rate of C. elegans fed with the mutants significantly increased compared to when fed with the parent strain. To our knowledge, this is the first report of the involvement of iron acquisition in the pathogenicity of UPEC in a C. elegans model.

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Biofilm Formation Protects Escherichia coli against Killing by Caenorhabditis elegans and Myxococcus xanthus

Applied and Environmental Microbiology ◽

10.1128/aem.02464-14 ◽

2014 ◽

Vol 80 (22) ◽

pp. 7079-7087 ◽

Cited By ~ 34

Author(s):

William H. DePas ◽

Adnan K. Syed ◽

Margarita Sifuentes ◽

John S. Lee ◽

David Warshaw ◽

...

Keyword(s):

Escherichia Coli ◽

Caenorhabditis Elegans ◽

Biofilm Formation ◽

Myxococcus Xanthus ◽

Enteric Bacteria ◽

Content Type ◽

E Coli ◽

C Elegans ◽

The Matrix ◽

Nutritional Environment

ABSTRACTEnteric bacteria, such asEscherichia coli, are exposed to a variety of stresses in the nonhost environment. The development of biofilms providesE. coliwith resistance to environmental insults, such as desiccation and bleach. We found that biofilm formation, specifically production of the matrix components curli and cellulose, protectedE. coliagainst killing by the soil-dwelling nematodeCaenorhabditis elegansand the predatory bacteriumMyxococcus xanthus. Additionally, matrix-encased bacteria at the air-biofilm interface exhibited ∼40-fold-increased survival afterC. elegansandM. xanthuskilling compared to the non-matrix-encased cells that populate the interior of the biofilm. To determine if nonhostEnterobacteriaceaereservoirs supported biofilm formation, we grewE. colion media composed of pig dung or commonly contaminated foods, such as beef, chicken, and spinach. Each of these medium types provided a nutritional environment that supported matrix production and biofilm formation. Altogether, we showed that common, nonhost reservoirs ofE. colisupported the formation of biofilms that subsequently protectedE. coliagainst predation.

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The Effect of Mianserin on Lifespan of Caenorhabditis elegans is Abolished by Glucose

Current Aging Science ◽

10.2174/1874609813999210104203614 ◽

2021 ◽

Vol 13 ◽

Author(s):

Abdullah Almotayri ◽

Jency Thomas ◽

Mihiri Munasinghe ◽

Markandeya Jois

Keyword(s):

Caenorhabditis Elegans ◽

Scaffolding Protein ◽

Lifespan Extension ◽

Wild Type ◽

E Coli ◽

C Elegans ◽

Risk Of Death ◽

Increased Risk ◽

Antidepressant Use ◽

Extension Effect

Background: The antidepressant mianserin has been shown to extend the lifespan of Caenorhabditis elegans (C. elegans), a well-established model organism used in aging research. The extension of lifespan in C. elegans was shown to be dependent on increased expression of the scaffolding protein (ANK3/unc-44). In contrast, antidepressant use in humans is associated with an increased risk of death. The C. elegans in the laboratory are fed Escherichia coli (E. coli), a diet high in protein and low in carbohydrate, whereas a typical human diet is high in carbohydrates. We hypothesized that dietary carbohydrates might mitigate the lifespan-extension effect of mianserin. Objective: To investigate the effect of glucose added to the diet of C. elegans on the lifespan-extension effect of mianserin. Methods: Wild-type Bristol N2 and ANK3/unc-44 inactivating mutants were cultured on agar plates containing nematode growth medium and fed E. coli. Treatment groups included (C) control, (M50) 50 μM mianserin, (G) 73 mM glucose, and (M50G) 50 μM mianserin and 73 mM glucose. Lifespan was determined by monitoring the worms until they died. Statistical analysis was performed using the Kaplan-Meier version of the log-rank test. Results: Mianserin treatment resulted in a 12% increase in lifespan (P<0.05) of wild-type Bristol N2 worms but reduced lifespan by 6% in ANK3/unc-44 mutants, consistent with previous research. The addition of glucose to the diet reduced the lifespan of both strains of worms and abolished the lifespan-extension by mianserin. Conclusion: The addition of glucose to the diet of C. elegans abolishes the lifespan-extension effects of mianserin.

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Temporal Transcriptomics of Gut Escherichia coli in Caenorhabditis elegans Models of Aging

Microbiology Spectrum ◽

10.1128/spectrum.00498-21 ◽

2021 ◽

Author(s):

Joshua D. Brycki ◽

Jeremy R. Chen See ◽

Gillian R. Letson ◽

Cade S. Emlet ◽

Lavinia V. Unverdorben ◽

...

Keyword(s):

Gene Expression ◽

Escherichia Coli ◽

Caenorhabditis Elegans ◽

Life Span ◽

Wild Type ◽

Health Span ◽

Content Type ◽

C Elegans ◽

Evolutionarily Conserved

Previous research has reported effects of the microbiome on health span and life span of Caenorhabditis elegans , including interactions with evolutionarily conserved pathways in humans. We build on this literature by reporting the gene expression of Escherichia coli OP50 in wild-type (N2) and three long-lived mutants of C. elegans .

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Insights into the Involvement of Spliceosomal Mutations in Myelodysplastic Disorders from Analysis of SACY-1/DDX41 in Caenorhabditis elegans

Genetics ◽

10.1534/genetics.119.302973 ◽

2020 ◽

Vol 214 (4) ◽

pp. 869-893 ◽

Cited By ~ 1

Author(s):

Tatsuya Tsukamoto ◽

Micah D. Gearhart ◽

Seongseop Kim ◽

Gemechu Mekonnen ◽

Caroline A. Spike ◽

...

Keyword(s):

Caenorhabditis Elegans ◽

Myelodysplastic Syndromes ◽

Missense Mutations ◽

Synthetic Lethal ◽

C Elegans ◽

Link Type ◽

Dead Box ◽

Synthetic Lethal Interactions ◽

Biochemical Analyses ◽

Cellular Phenotypes

Mutations affecting spliceosomal proteins are frequently found in hematological malignancies, including myelodysplastic syndromes and acute myeloid leukemia (AML). DDX41/Abstrakt is a metazoan-specific spliceosomal DEAD-box RNA helicase that is recurrently mutated in inherited myelodysplastic syndromes and in relapsing cases of AML. The genetic properties and genomic impacts of disease-causing missense mutations in DDX41 and other spliceosomal proteins have been uncertain. Here, we conduct a comprehensive analysis of the Caenorhabditis elegans DDX41 ortholog, SACY-1. Biochemical analyses defined SACY-1 as a component of the C. elegans spliceosome, and genetic analyses revealed synthetic lethal interactions with spliceosomal components. We used the auxin-inducible degradation system to analyze the consequence of SACY-1 depletion on the transcriptome using RNA sequencing. SACY-1 depletion impacts the transcriptome through splicing-dependent and splicing-independent mechanisms. Altered 3′ splice site usage represents the predominant splicing defect observed upon SACY-1 depletion, consistent with a role for SACY-1 in the second step of splicing. Missplicing events appear more prevalent in the soma than the germline, suggesting that surveillance mechanisms protect the germline from aberrant splicing. The transcriptome changes observed after SACY-1 depletion suggest that disruption of the spliceosome induces a stress response, which could contribute to the cellular phenotypes conferred by sacy-1 mutant alleles. Multiple sacy-1/ddx41 missense mutations, including the R525H human oncogenic variant, confer antimorphic activity, suggesting that their incorporation into the spliceosome is detrimental. Antagonistic variants that perturb the function of the spliceosome may be relevant to the disease-causing mutations, including DDX41, affecting highly conserved components of the spliceosome in humans.

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