scholarly journals Identification of gmhA, a Yersinia pestis Gene Required for Flea Blockage, by Using a Caenorhabditis elegans Biofilm System

2005 ◽  
Vol 73 (11) ◽  
pp. 7236-7242 ◽  
Author(s):  
Creg Darby ◽  
Sandya L. Ananth ◽  
Li Tan ◽  
B. Joseph Hinnebusch
Keyword(s):  
Caenorhabditis Elegans ◽  
Yersinia Pestis ◽  
Biofilm Formation ◽  
Yersinia Pseudotuberculosis ◽  
C Elegans ◽  
Transposon Insertion ◽  
Insertion Mutants ◽  
Random Screening

ABSTRACT Yersinia pestis, the cause of bubonic plague, blocks feeding by its vector, the flea. Recent evidence indicates that blockage is mediated by an in vivo biofilm. Y. pestis and the closely related Yersinia pseudotuberculosis also make biofilms on the cuticle of the nematode Caenorhabditis elegans, which block this laboratory animal's feeding. Random screening of Y. pseudotuberculosis transposon insertion mutants with a C. elegans biofilm assay identified gmhA as a gene required for normal biofilms. gmhA encodes phosphoheptose isomerase, an enzyme required for synthesis of heptose, a conserved component of lipopolysaccharide and lipooligosaccharide. A Y. pestis gmhA mutant was constructed and was severely defective for C. elegans biofilm formation and for flea blockage but only moderately defective in an in vitro biofilm assay. These results validate use of the C. elegans biofilm system to identify genes and pathways involved in Y. pestis flea blockage.

scholarly journals Serotype Differences and Lack of Biofilm Formation Characterize Yersinia pseudotuberculosis Infection of the Xenopsylla cheopis Flea Vector of Yersinia pestis

2006 ◽  
Vol 188 (3) ◽  
pp. 1113-1119 ◽  
Author(s):  
David L. Erickson ◽  
Clayton O. Jarrett ◽  
Brendan W. Wren ◽  
B. Joseph Hinnebusch
Keyword(s):  
Yersinia Pestis ◽  
Biofilm Formation ◽  
Yersinia Pseudotuberculosis ◽  
Ex Vivo ◽  
Blood Feeding ◽  
Genetic Change ◽  
Xenopsylla Cheopis ◽  
C Elegans ◽  
Transmissible Infection

ABSTRACT Yersinia pestis, the agent of plague, is usually transmitted by fleas. To produce a transmissible infection, Y. pestis colonizes the flea midgut and forms a biofilm in the proventricular valve, which blocks normal blood feeding. The enteropathogen Yersinia pseudotuberculosis, from which Y. pestis recently evolved, is not transmitted by fleas. However, both Y. pestis and Y. pseudotuberculosis form biofilms that adhere to the external mouthparts and block feeding of Caenorhabditis elegans nematodes, which has been proposed as a model of Y. pestis-flea interactions. We compared the ability of Y. pestis and Y. pseudotuberculosis to infect the rat flea Xenopsylla cheopis and to produce biofilms in the flea and in vitro. Five of 18 Y. pseudotuberculosis strains, encompassing seven serotypes, including all three serotype O3 strains tested, were unable to stably colonize the flea midgut. The other strains persisted in the flea midgut for 4 weeks but did not increase in numbers, and none of the 18 strains colonized the proventriculus or produced a biofilm in the flea. Y. pseudotuberculosis strains also varied greatly in their ability to produce biofilms in vitro, but there was no correlation between biofilm phenotype in vitro or on the surface of C. elegans and the ability to colonize or block fleas. Our results support a model in which a genetic change in the Y. pseudotuberculosis progenitor of Y. pestis extended its pre-existing ex vivo biofilm-forming ability to the flea gut environment, thus enabling proventricular blockage and efficient flea-borne transmission.

scholarly journals Caenorhabditis elegans as an in vivo Model to Assess Amphetamine Tolerance

2021 ◽  
pp. 1-9
Author(s):  
Dayana Torres Valladares ◽  
Sirisha Kudumala ◽  
Murad Hossain ◽  
Lucia Carvelli
Keyword(s):  
Caenorhabditis Elegans ◽  
Molecular Mechanisms ◽  
Drugs Of Abuse ◽  
Genetic Model ◽  
In Vivo Model ◽  
C Elegans ◽  
Hyperactivity Disorder ◽  
In Vitro Data

Amphetamine is a potent psychostimulant also used to treat attention deficit/hyperactivity disorder and narcolepsy. In vivo and in vitro data have demonstrated that amphetamine increases the amount of extra synaptic dopamine by both inhibiting reuptake and promoting efflux of dopamine through the dopamine transporter. Previous studies have shown that chronic use of amphetamine causes tolerance to the drug. Thus, since the molecular mechanisms underlying tolerance to amphetamine are still unknown, an animal model to identify the neurochemical mechanisms associated with drug tolerance is greatly needed. Here we took advantage of a unique behavior caused by amphetamine in <i>Caenorhabditis elegans</i> to investigate whether this simple, but powerful, genetic model develops tolerance following repeated exposure to amphetamine. We found that at least 3 treatments with 0.5 mM amphetamine were necessary to see a reduction in the amphetamine-induced behavior and, thus, to promote tolerance. Moreover, we found that, after intervals of 60/90 minutes between treatments, animals were more likely to exhibit tolerance than animals that underwent 10-minute intervals between treatments. Taken together, our results show that <i>C. elegans</i> is a suitable system to study tolerance to drugs of abuse such as amphetamines.

scholarly journals Rosemary Flowers as Edible Plant Foods: Phenolic Composition and Antioxidant Properties in Caenorhabditis elegans

Antioxidants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 811
Author(s):  
Cristina Moliner ◽  
Víctor López ◽  
Lillian Barros ◽  
Maria Inês Dias ◽  
Isabel C. F. R. Ferreira ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Antioxidant Properties ◽  
Ethanolic Extract ◽  
Food Ingredient ◽  
Edible Plant ◽  
Phenolic Profile ◽  
C Elegans ◽  
Rosmarinus Officinalis L

Rosmarinus officinalis L., commonly known as rosemary, has been largely studied for its wide use as food ingredient and medicinal plant; less attention has been given to its edible flowers, being necessary to evaluate their potential as functional foods or nutraceuticals. To achieve that, the phenolic profile of the ethanolic extract of R. officinalis flowers was determined using LC-DAD-ESI/MSn and then its antioxidant and anti-ageing potential was studied through in vitro and in vivo assays using Caenorhabditis elegans. The phenolic content was 14.3 ± 0.1 mg/g extract, trans rosmarinic acid being the predominant compound in the extract, which also exhibited a strong antioxidant capacity in vitro and increased the survival rate of C. elegans exposed to lethal oxidative stress. Moreover, R. officinalis flowers extended C. elegans lifespan up to 18%. Therefore, these findings support the potential use of R. officinalis flowers as ingredients to develop products with pharmaceutical and/or nutraceutical potential.

scholarly journals Mulberry Anthocyanin Extract Ameliorates Oxidative Damage in HepG2 Cells and Prolongs the Lifespan of Caenorhabditis elegans through MAPK and Nrf2 Pathways

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Fujie Yan ◽  
Yushu Chen ◽  
Ramila Azat ◽  
Xiaodong Zheng
Keyword(s):  
Oxidative Stress ◽  
Caenorhabditis Elegans ◽  
Hepg2 Cells ◽  
Insulin Signalling ◽  
Glucose Consumption ◽  
Redox Status ◽  
C Elegans ◽  
Beneficial Effects

Mulberry anthocyanins possess many pharmacological effects including liver protection, anti-inflammation, and anticancer. The aim of this study was to evaluate whether mulberry anthocyanin extract (MAE) exerts beneficial effects against oxidative stress damage in HepG2 cells and Caenorhabditis elegans. In vitro, MAE prevented cytotoxicity, increased glucose consumption and uptake, and eliminated excessive intracellular free radicals in H2O2-induced cells. Moreover, MAE pretreatment maintained Nrf2, HO-1, and p38 MAPK stimulation and abolished upregulation of p-JNK, FOXO1, and PGC-1α that were involved in oxidative stress and insulin signalling modulation. In vivo, extended lifespan was observed in C. elegans damaged by paraquat in the presence of MAE, while these beneficial effects were disappeared in pmk-1 and daf-16 mutants. PMK-1 and SKN-1 were activated after exposure to paraquat and MAE suppressed PMK-1 activation but enhanced SKN-1 stimulation. Our findings suggested that MAE recovered redox status in HepG2 cells and C. elegans that suffered from oxidative stress, which might be by targeting MAPKs and Nrf2.

scholarly journals Identification of phenolic secondary metabolites from Schotia brachypetala Sond. (Fabaceae) and demonstration of their antioxidant activities in Caenorhabditis elegans

2016 ◽  
Author(s):  
Mansour Sobeh ◽  
Esraa A ElHawary ◽  
Herbenya Peixoto ◽  
Rola M Labib ◽  
Heba Handoussa ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Caenorhabditis Elegans ◽  
Nuclear Translocation ◽  
Antioxidant Activities ◽  
In Vitro Assays ◽  
Flavonoid Glycosides ◽  
Alcoholic Extract ◽  
C Elegans

Background: Schotia brachypetala Sond. (Fabaceae) is an endemic tree of Southern Africa whose phytochemistry and pharmacology were slightly studied.The present work aimed at profiling the major phenolics compounds present in the hydro-alcoholic extract from S. brachypetala leaves (SBE) using LC/HRESI/MS/MS and NMR and prove their antioxidant capabilities using novel methods. Methods: In vitro assays; DPPH, TEAC persulfate decolorizing kinetic and FRAP assays, and in vivo assays: Caenorhabditis elegans strains maintenance, Intracellular ROS in C. elegans, Survival assay, GFP expression and Subcellular DAF-16 localization were employed to evaluate the antioxidant activity. Results: More than forty polyphenols ,including flavonoid glycosides, galloylated flavonoid glycosides, isoflavones, dihydrochalcones, procyanidins, anthocyanins, hydroxybenzoic acid derivatives, hydrolysable tannins, and traces of methylated and acetylated flavonoid derivatives were identified. Three compounds were isolated and identified from the genus Schotia for the first time, namely gallic acid, myricetin-3-O-α-L-1C4-rhamnoside and quercetin-3-O-L-1C4-rhamnoside.The tested extract was able to protect the worms against juglone induced oxidative stress and attenuate the reactive oxygen species (ROS) accumulation. SBE was also able to attenuate the levels of heat shock protein (HSP) expression. Discussion: A pronounced antioxidant activity in vivo, which can be attributed to its ability to promote the nuclear translocation of DAF-16/FOXO, the main transcription factor regulating the expression of stress response genes. The remarkable antioxidant activity in vitro and in vivo correlates to SBE rich phenolic profile.

scholarly journals Polyphenols from Blumea laciniata Extended the Lifespan and Enhanced Resistance to Stress in Caenorhabditis elegans via the Insulin Signaling Pathway

Antioxidants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1744
Author(s):  
Tao Chen ◽  
Siyuan Luo ◽  
Xiaoju Wang ◽  
Yiling Zhou ◽  
Yali Dai ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Signaling Pathway ◽  
Relevant Literature ◽  
Folk Medicine ◽  
Ageing Effect ◽  
C Elegans ◽  
Enhanced Resistance ◽  
Resistance To Stress

Blumea laciniata is widely used as a folk medicine in Asia, but relevant literature on it is rarely reported. We confirmed that polyphenol extract (containing chlorogenic acid, rutin, and luteolin-4-O-glucoside) from B. laciniata (EBL) showed strong antioxidant ability in vitro. Hence, in this work, we applied Caenorhabditis elegans to further investigate the antioxidant and anti-ageing abilities of EBL in vivo. The results showed that EBL enhanced the survival of C. elegans under thermal stress by 12.62% and sharply reduced the reactive oxygen species level as well as the content of malonaldehyde. Moreover, EBL increased the activities of antioxidant enzymes such as catalase and superoxide dismutase. Additionally, EBL promoted DAF-16, a transcription factor, into the nucleus. Besides, EBL extended the lifespan of C. elegans by 17.39%, showing an anti-ageing effect. Different mutants indicated that the insulin/IGF-1 signaling pathway participated in the antioxidant and anti-ageing effect of EBL on C. elegans.

scholarly journals A fast and reliable method for monitoring genomic instability in the model organism Caenorhabditis elegans

2021 ◽  
Author(s):  
Merle Marie Nicolai ◽  
Barbara Witt ◽  
Andrea Hartwig ◽  
Tanja Schwerdtle ◽  
Julia Bornhorst
Keyword(s):  
Caenorhabditis Elegans ◽  
Animal Experiments ◽  
Model Organism ◽  
Animal Testing ◽  
C Elegans ◽  
Testing Strategies ◽  
Genotoxic Agents ◽  
Genotoxicity Testing

AbstractThe identification of genotoxic agents and their potential for genotoxic alterations in an organism is crucial for risk assessment and approval procedures of the chemical and pharmaceutical industry. Classically, testing strategies for DNA or chromosomal damage focus on in vitro and in vivo (mainly rodent) investigations. In cell culture systems, the alkaline unwinding (AU) assay is one of the well-established methods for detecting the percentage of double-stranded DNA (dsDNA). By establishing a reliable lysis protocol, and further optimization of the AU assay for the model organism Caenorhabditis elegans (C. elegans), we provided a new tool for genotoxicity testing in the niche between in vitro and rodent experiments. The method is intended to complement existing testing strategies by a multicellular organism, which allows higher predictability of genotoxic potential compared to in vitro cell line or bacterial investigations, before utilizing in vivo (rodent) investigations. This also allows working within the 3R concept (reduction, refinement, and replacement of animal experiments), by reducing and possibly replacing animal testing. Validation with known genotoxic agents (bleomycin (BLM) and tert-butyl hydroperoxide (tBOOH)) proved the method to be meaningful, reproducible, and feasible for high-throughput genotoxicity testing, and especially preliminary screening.

scholarly journals Detecting changes in the Caenorhabditis elegans intestinal environment using an engineered bacterial biosensor

2019 ◽  
Author(s):  
Jack W. Rutter ◽  
Tanel Ozdemir ◽  
Leonor M. Quintaneiro ◽  
Geraint Thomas ◽  
Filipe Cabreiro ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Rational Design ◽  
Model Organism ◽  
Bacterial Biosensor ◽  
Intestinal Environment ◽  
C Elegans ◽  
Ideal Candidate ◽  
Diagnostic Applications

AbstractCaenorhabditis elegans has become a key model organism within biology. In particular, the transparent gut, rapid growing time and ability to create a defined gut microbiota make it an ideal candidate organism for understanding and engineering the host microbiota. Here we present the development of an experimental model which can be used to characterise whole-cell bacterial biosensors in vivo. A dual-plasmid sensor system responding to isopropyl β-D-1-thiogalactopyranoside was developed and fully characterised in vitro. Subsequently, we show the sensor was capable of detecting and reporting on changes in the intestinal environment of C. elegans after introducing exogenous inducer into the environment. The protocols presented here may be used for aiding the rational design of engineered bacterial circuits, primarily for diagnostic applications. In addition, the model system may serve to reduce the use of current animal models and aid in the exploration of complex questions within general nematode and host-microbe biology.

scholarly journals Differential Gene Expression Patterns ofYersinia pestisandYersinia pseudotuberculosisduring Infection and Biofilm Formation in the Flea Digestive Tract

mSystems ◽  
2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Iman Chouikha ◽  
Daniel E. Sturdevant ◽  
Clayton Jarrett ◽  
Yi-Cheng Sun ◽  
B. Joseph Hinnebusch
Keyword(s):  
Digestive Tract ◽  
Biofilm Formation ◽  
Yersinia Pseudotuberculosis ◽  
Expression Patterns ◽  
Type Vi Secretion System ◽  
Genetic Changes ◽  
Content Type ◽  
Biofilm Development

ABSTRACTYersinia pestis, the etiologic agent of plague, emerged as a fleaborne pathogen only within the last 6,000 years. Just five simple genetic changes in theYersinia pseudotuberculosisprogenitor, which served to eliminate toxicity to fleas and to enhance survival and biofilm formation in the flea digestive tract, were key to the transition to the arthropodborne transmission route. To gain a deeper understanding of the genetic basis for the development of a transmissible biofilm infection in the flea foregut, we evaluated additional gene differences and performedin vivotranscriptional profiling ofY. pestis, aY. pseudotuberculosiswild-type strain (unable to form biofilm in the flea foregut), and aY. pseudotuberculosismutant strain (able to produce foregut-blocking biofilm in fleas) recovered from fleas 1 day and 14 days after an infectious blood meal. Surprisingly, theY. pseudotuberculosismutations that increased c-di-GMP levels and enabled biofilm development in the flea did not change the expression levels of thehmsgenes responsible for the synthesis and export of the extracellular polysaccharide matrix required for mature biofilm formation. TheY. pseudotuberculosismutant uniquely expressed much higher levels ofYersiniatype VI secretion system 4 (T6SS-4) in the flea, and this locus was required for flea blockage byY. pseudotuberculosisbut not for blockage byY. pestis. Significant differences between the two species in expression of several metabolism genes, the Psa fimbrial genes, quorum sensing-related genes, transcription regulation genes, and stress response genes were evident during flea infection.IMPORTANCEY. pestisemerged as a highly virulent, arthropod-transmitted pathogen on the basis of relatively few and discrete genetic changes fromY. pseudotuberculosis. Parallel comparisons of thein vitroandin vivotranscriptomes ofY. pestisand twoY. pseudotuberculosisvariants that produce a nontransmissible infection and a transmissible infection of the flea vector, respectively, provided insights into howY. pestishas adapted to life in its flea vector and point to evolutionary changes in the regulation of metabolic and biofilm development pathways in these two closely related species.

Abstract 90: Serum Kawasaki Disease-specific Microbe-associated Molecular Patterns are Derived from in Vitro and in Vivo Biofilms

Circulation ◽  
2015 ◽  
Vol 131 (suppl_2) ◽  
Author(s):  
Takeshi Kusuda ◽  
Yasutaka Nakashima ◽  
Murata Kenji ◽  
Shunsuke Kanno ◽  
Mitsumasa Saito ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Yersinia Pseudotuberculosis ◽  
Molecular Structures ◽  
Human Coronary Artery ◽  
Medium Temperature ◽  
Molecular Patterns ◽  
Culture Supernatants

Background: We have found that serum KD-specific molecules possess molecular structures common to microbe-associated molecular patterns (MAMPs) from several bacteria by liquid chromatography-mass spectrometry (LC-MS) analysis. In the present study, we have extensively searched for the culture conditions that reproducibly produce MAMPs common to serum KD specific molecules. Methods: Yersinia pseudotuberculosis, spore-forming bacteria and pathogenic bacteria were obtained from KD patients. Others were purchased from American Type Culture Collection. Microbes were cultured in a variety of conditions (medium, temperature, duration, shaking and biofilm formation). For biofilm formation, a various kind of oil/butter was added to the culture medium. Extraction from in vitro samples (culture supernatants, bacteria cells, and biofilms) as well as in vivo biofilm samples (teeth, tongue, nasal cavity, or rectum) was performed with ethyl acetate. Samples were analyzed by HPLC and MS (Esquire 6000 electrospray ionization). Human coronary artery endothelial cells (HCAECs) were employed for cytokine assay. The concentrations of cytokines were measured by EC800 cell analyzer with a BD™ Cytometric Bead Array. Results: Serum KD-specific molecules showed m/z and MS/MS fragmentation patterns almost identical to those of MAMPs obtained from the biofilms formed in vitro (Bacillus cereus, Bacillus subtilis, Yersinia pseudotuberculosis, Staphylococcus aureus) or in vivo. Not culture supernatants but biofilm extracts from these bacteria, especially cultured in the presence of butter, induced proinflammatory cytokines by HCAECs. Conclusions: Extensive analysis by LC-MS/MS revealed that serum KD-specific molecules common to MAMPs were mostly derived from biofilms in vitro and in vivo. This report offers novel insight into the pathogenesis of KD.

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