scholarly journals Colonization with heterologous bacteria reprograms a Caenorhabditis elegans nutritional phenotype

2020 ◽  
Author(s):  
Qing Sun ◽  
Nicole M. Vega ◽  
Bernardo Cervantes ◽  
Christopher P. Mancuso ◽  
Ning Mao ◽  
...  

AbstractAnimals rely on the gut microbiome to process complex food compounds that the host cannot digest and to synthesize nutrients that the host cannot produce. New systems are needed to study how the expanded metabolic capacity provided by the gut microbiome impacts the nutritional status and health of the host. Here we colonized the nematode Caenorhabditis elegans gut with cellulolytic bacteria that enabled C. elegans to utilize cellulose, an otherwise indigestible substrate, as a carbon source. The nutritional benefits of colonization with cellulolytic bacteria were assayed directly, by incorporation of isotopic biomass, and indirectly, as host larval yield resulting from glucose release in the gut. As a community component in the worm gut, cellulolytic bacteria can also support additional bacterial species with specialized roles, which we demonstrate by using Lactobacillus to protect against Salmonella infection. As a model system, C. elegans colonized with cellulolytic bacteria can be used to study microbiome-host interactions. Engineered microbiome communities may provide host organisms with novel functions, such as the ability to use more complex nutrient sources and to fight against pathogen infections.One Sentence SummaryHeterologous bacteria colonizing an animal gut help digest complex sugars to provide nutrition for the host in a model system.

2021 ◽  
Author(s):  
Rui Han ◽  
Yu Wang ◽  
Yang Deng ◽  
Yuqin Zhang ◽  
Lin Zhang ◽  
...  

Abstract The soil-dwelling opportunistic bacterium Bacillus nematocida B16 shows comparatively strong killing activities against a variety of pathogenic nematodes. A bacterial strain CPCC 101271T, isolated from intestines of C. elegans in natural habitats, was found not only to be probiotics for C. elegans but also assist in resisting pathogen B16 infection. The lifespan of Caenorhabditis elegans fed on strain CPCC 101271T was extended by approximately 40% compared with that of worms fed on Escherichia coli OP50. In addition, the colonization of C. elegans by the pathogenic bacterium B. nematocida B16 was inhibited when it was pre-fed with strain CPCC 101271T. Based on a polyphasic taxonomy study including genotypic, chemotaxonomic and phenotypic characteristics, we propose that strain CPCC 101271T represents a novel bacterial species with the name Stenotrophomonas nematodicola sp. nov. and CPCC 101271T as the type strain. Metagenomic sequence analysis of the intestinal microbiota of C. elegans fed with strain CPCC 101271T and then infected with B16 revealed that pre-feeding with CPCC 101271T improved the diversity of intestinal bacteria, while the community structure varied significantly together with the fluctuation of Stenotrophomonas spp. and Bacillus spp. abundance during competition between strain CPCC 101271T and B16. In conclusion, the nematode microbiota strain CPCC 101271T, a novel species of the genus Stenotrophomonas, assisted in its host resistance to the pathogen Bacillus nematocida colonization, so as to act as an intestinal life span-prolonging for C. elegans.


2020 ◽  
Vol 64 (10) ◽  
Author(s):  
Ainara Hernando-Ortiz ◽  
Estibaliz Mateo ◽  
Marcelo Ortega-Riveros ◽  
Iker De-la-Pinta ◽  
Guillermo Quindós ◽  
...  

ABSTRACT Although Candida albicans remains the major etiological agent of invasive candidiasis, Candida glabrata and other emerging species of Candida are increasingly isolated. This species is the second most prevalent cause of candidiasis in many regions of the world. However, clinical isolates of Candida nivariensis and Candida bracarensis can be misidentified and are underdiagnosed due to phenotypic traits shared with C. glabrata. Little is known about the two cryptic species. Therefore, pathogenesis studies are needed to understand their virulence traits and their susceptibility to antifungal drugs. The susceptibility of Caenorhabditis elegans to different Candida species makes this nematode an excellent model for assessing host-fungus interactions. We evaluated the usefulness of C. elegans as a nonconventional host model to analyze the virulence of C. glabrata, C. nivariensis, and C. bracarensis. The three species caused candidiasis, and the highest virulence of C. glabrata was confirmed. Furthermore, we determined the efficacy of current antifungal drugs against the infection caused by these species in the C. elegans model. Amphotericin B and azoles showed the highest activity against C. glabrata and C. bracarensis infections, while echinocandins were more active for treating those caused by C. nivariensis. C. elegans proved to be a useful model system for assessing the pathogenicity of these closely related species.


2017 ◽  
Vol 91 (23) ◽  
Author(s):  
Don B. Gammon

ABSTRACT Since 1999, Caenorhabditis elegans has been extensively used to study microbe-host interactions due to its simple culture, genetic tractability, and susceptibility to numerous bacterial and fungal pathogens. In contrast, virus studies have been hampered by a lack of convenient virus infection models in nematodes. The recent discovery of a natural viral pathogen of C. elegans and development of diverse artificial infection models are providing new opportunities to explore virus-host interplay in this powerful model organism.


2017 ◽  
Vol 74 (8) ◽  
pp. 1173-1179 ◽  
Author(s):  
Joshua Coulter Russell ◽  
Nikolay Burnaevskiy ◽  
Bridget Ma ◽  
Miguel Arenas Mailig ◽  
Franklin Faust ◽  
...  

Abstract The function of the pharynx, an organ in the model system Caenorhabditis elegans, has been correlated with life span and motility (another measure of health) since 1980. In this study, in order to further understand the relationship between organ function and life span, we measured the age-related decline of the pharynx using an electrophysiological approach. We measured and analyzed electropharyngeograms (EPG) of wild type animals, short-lived hsf-1 mutants, and long-lived animals with genetically decreased insulin signaling or increased heat shock pathway signaling; we recorded a total of 2,478 EPGs from 1,374 individuals. As expected, the long-lived daf-2(e1370) and hsf-1OE(uthIs235) animals maintained pharynx function relatively closer to the youthful state during aging, whereas the hsf-1(sy441) and wild type animals’ pharynx function deviated significantly further from the youthful state at advanced age. Measures of the amount of variation in organ function can act as biomarkers of youthful physiology as well. Intriguingly, the long-lived animals had greater variation in the duration of pharynx contraction at older ages.


PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e1879 ◽  
Author(s):  
Erjia Wang ◽  
Michael Wink

Green vegetables are thought to be responsible for several beneficial properties such as antioxidant, anti-mutagenic, and detoxification activities. It is not known whether these effects are due to chlorophyll which exists in large amounts in many foods or result from other secondary metabolites. In this study, we used the model systemCaenorhabditis elegansto investigate the anti-oxidative and anti-aging effects of chlorophyllin vivo. We found that chlorophyll significantly improves resistance to oxidative stress. It also enhances the lifespan ofC. elegansby up to 25% via activation of the DAF-16/FOXO-dependent pathway. The results indicate that chlorophyll is absorbed by the worms and is thus bioavailable, constituting an important prerequisite for antioxidant and longevity-promoting activities inside the body. Our study thereby supports the view that green vegetables may also be beneficial for humans.


Author(s):  
Sri Nitya Reddy Induri ◽  
Payalben Kansara ◽  
Scott C. Thomas ◽  
Fangxi Xu ◽  
Deepak Saxena ◽  
...  

Metformin has been extensively used for the treatment of type 2 diabetes, and it may also promote healthy aging. Despite its widespread use and versatility, metformin's mechanisms of action remain elusive. The gut typically harbors thousands of bacterial species, and as the concentration of metformin is much higher in the gut as compared to plasma, it is plausible that microbiome-drug-host interactions may influence the functions of metformin. Detrimental perturbations in the aging gut microbiome lead to the activation of the innate immune response concomitant with chronic low-grade inflammation. With the effectiveness of metformin in diabetes and antiaging varying among individuals, there is reason to believe that the gut microbiome plays a role in the efficacy of metformin. Metformin has been implicated in the promotion and maintenance of a healthy gut microbiome and reduces many age-related degenerative pathologies. Mechanistic understanding of metformin in the promotion of a healthy gut microbiome and aging will require a systems-level approach. Expected final online publication date for the Annual Review of Pharmacology and Toxicology, Volume 62 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.


2021 ◽  
Author(s):  
Lin Zhang ◽  
Yang Deng ◽  
Xuyang Wei ◽  
Yuqin Zhang ◽  
Qiuhong Niu

Abstract Background: The gut microbiota of Caenorhabditis elegans, a tiny worm that feeds on bacteria, is significantly dominated by the bacteria upon which it feeds. These bacteria may not only interfere with the intestinal flora of C. elegans but also assist in resisting pathogen infection. Understanding the interactions between the microbiota of C. elegans and pathogens will shed light on how to achieve biological control of agricultural pests. Results: The lifespan of Caenorhabditis elegans fed on strain CPCC 101271T was extended by approximately 40% compared with that of worms fed on Escherichia coli OP50. In addition, the colonization of C. elegans by the pathogenic bacterium Bacillus nematocida B16 was inhibited when it was pre-fed with strain CPCC 101271T. Based on a polyphasic taxonomy study including genotypic, chemotaxonomic and phenotypic characteristics, we propose that strain CPCC 101271T represents a novel bacterial species with the name Stenotrophomonas nematodicola sp. nov. and CPCC 101271T as the type strain. Metagenomic sequence analysis of the intestinal microbiota of C. elegans fed with strain CPCC 101271T and then infected with B16 revealed that pre-feeding with CPCC 101271T improved the diversity of intestinal bacteria, while the community structure varied significantly together with the fluctuation of Stenotrophomonas spp. and Bacillus spp. abundance during competition between strain CPCC 101271T and B16. Conclusions: The nematode microbiota strain CPCC 101271T assisted in its host resistance to the pathogen Bacillus nematocida colonization, so as to act as an intestinal life span-prolonging bacterium for C. elegans. The genotypic and phenotypic properties of strain CPCC 101271T supported to the proposal of strain CPCC 101271T as a novel species of the genus Stenotrophomonas.


2001 ◽  
Vol 356 (1414) ◽  
pp. 1521-1531 ◽  
Author(s):  
Bob Goldstein

The phylum Nematoda serves as an excellent model system for exploring how development evolves, using a comparative approach to developmental genetics. More than 100 laboratories are studying developmental mechanisms in the nematode Caenorhabditis elegans , and many of the methods that have been developed for C. elegans can be applied to other nematodes. This review summarizes what is known so far about steps in early development that have evolved in the nematodes, and proposes potential experiments that could make use of these data to further our understanding of how development evolves. The promise of such a comparative approach to developmental genetics is to fill a wide gap in our understanding of evolution—a gap spanning from mutations in developmental genes through to their phenotypic results, on which natural selection may act.


Author(s):  
Kitlangki Suchiang ◽  
Nitasha H Kayde

Background: Phlogacanthus thyrsiflorus Nees (P. thyrsiflorus) of Acanthaceae family is endogenous to sub-tropical Himalayas. It has been reported to be used traditionally in Jaintia tribe of Meghalaya, India for treatment of many ailments.Objectives: The aim was to detect the active compounds present in the leaves for evaluation of in vitro free radicals scavenging potentials. Leaves protective actions in vivo will be investigated using Caenorhabditis elegans (C. elegans) model system utilizing wild type and mutant strains and the phenomena of host-pathogens interactions.Materials and methods: Gas chromatography/ Mass spectrometry (GC/MS) was used for detection of different compounds present. The versatility of leaf extracts to scavenge different free radicals generated in vitro was assessed with different in vitro methods. Survival analysis of wild type and mutant strains C. elegans under enhanced pro-oxidants exposure was investigated in vivo. Fast killing assay was also performed to study the extracts modulatory activity on host C. elegans survival under pathogen Pseudomonas aeruginosa infection.Results:  Forty compounds were detected in methanolic fraction of the extract with variable percentages. Both aqueous and methanol extract possessed remarkable, versatile free radical scavenging activity irrespective of the types of free radical generated. The in vivo experiments are in compliance, with observable increased survival ability percentage of C. elegans under intense exogenous oxidative stress and pathogen infection.Conclusion: Our findings enlightened the different compounds present with versatility of P. thyrsiflorus in tackling different free radicals generated both in vitro and in vivo that highly support for its candidature as a good antioxidant source. Our findings may justify the historical relevance of this plant in herbal remedies that could form the basis for inquiry of new active principles.Keywords: Free radicals, Oxidative stress, Caenorhabditis elegans, Phlogacanthus thyrsiflorus, Phytochemicals


2020 ◽  
Vol 8 (4) ◽  
pp. 618
Author(s):  
Yuqing Huang ◽  
Jan E. Kammenga

The bacterivorous nematode Caenorhabditis elegans is an important model species for understanding genetic variation of complex traits. So far, most studies involve axenic laboratory settings using Escherichia coli as the sole bacterial species. Over the past decade, however, investigations into the genetic variation of responses to pathogenic microbiota have increasingly received attention. Quantitative genetic analyses have revealed detailed insight into loci, genetic variants, and pathways in C. elegans underlying interactions with bacteria, microsporidia, and viruses. As various quantitative genetic platforms and resources like C. elegans Natural Diversity Resource (CeNDR) and Worm Quantitative Trait Loci (WormQTL) have been developed, we anticipate that expanding C. elegans research along the lines of genetic variation will be a treasure trove for opening up new insights into genetic pathways and gene functionality of microbiota interactions.


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