scholarly journals Impacts of a novel defensive symbiosis on the nematode host microbiome

2020 ◽  
Author(s):  
Dylan Dahan ◽  
Gail M. Preston ◽  
Jordan Sealey ◽  
Kayla C. King
Keyword(s):  
Enterococcus Faecalis ◽  
Species Interactions ◽  
Bacterial Species ◽  
Pathogen Resistance ◽  
Ecological Impacts ◽  
Minimal Impact ◽  
C Elegans ◽  
Micro Organisms ◽  
Microbiota Diversity

Abstract Background: Bacteria adapted to live within animals can protect their hosts against harmful infections. Beyond antagonism with pathogens, a ‘defensive’ bacterial symbiont could engage in additional interactions with other colonizing micro-organisms. A single bacterium might thus have cascading ecological impacts on the whole microbiome that are rarely investigated. Here, we assess the role of a defensive symbiont as a driver of host-associated microbiota composition by using a bacterial species ( Enterococcus faecalis ) that was previously experimentally adapted ( Enterococcus faecalis ) to a nematode host model ( Caenorhabditis elegans ). Results: An analysis of 16S rRNA data from C. elegans exposed to E. faecalis and subsequently reared in soil, reveal that symbiont adaptation to host environment or its protective potential had minimal impact on microbiota diversity. Whilst the abundance of Pseudomonas was higher in the microbiota of hosts with protective E.faecalis (and another protective species tested), three other genera – Serratia, Klebsiella and Salinispora – were less abundant in hosts colonized by all E. faecalis strains. In addition, the protective effect of E. faecalis against opportunistic Staphylococcus aureus pathogens was maintained despite multi-species interactions within the microbiota. Conclusions: Our results reveal the degree to which a new, evolving symbiont can colonise and maintain its conferred phenotype (i.e., pathogen-resistance) with minimal disruption to the host microbiota diversity.

scholarly journals Impacts of a novel defensive symbiosis on the nematode host microbiome

2020 ◽  
Author(s):  
Dylan Dahan ◽  
Gail M. Preston ◽  
Jordan Sealey ◽  
Kayla C. King
Keyword(s):  
Enterococcus Faecalis ◽  
Species Interactions ◽  
Bacterial Species ◽  
Pathogen Resistance ◽  
Ecological Impacts ◽  
Minimal Impact ◽  
C Elegans ◽  
Micro Organisms ◽  
Microbiota Diversity

Abstract Background: Bacteria adapted to live within animals can protect their hosts against harmful infections. Beyond antagonism with pathogens, a ‘defensive’ bacterial symbiont could engage in additional interactions with other colonizing micro-organisms. A single bacterium might thus have cascading ecological impacts on the whole microbiome that are rarely investigated. Here, we assess the role of a defensive symbiont as a driver of host-associated microbiota composition by using a bacterial species (Enterococcus faecalis) that was previously experimentally adapted (Enterococcus faecalis) to a nematode host model (Caenorhabditis elegans). Results: An analysis of 16S rRNA data from C. elegans exposed to E. faecalis and subsequently reared in soil, reveal that symbiont adaptation to host environment or its protective potential had minimal impact on microbiota diversity. Whilst the abundance of Pseudomonas was higher in the microbiota of hosts with protective E.faecalis (and another protective species tested), three other genera – Serratia, Klebsiella and Salinispora – were less abundant in hosts colonized by all E. faecalis strains. In addition, the protective effect of E. faecalis against opportunistic Staphylococcus aureus pathogens was maintained despite multi-species interactions within the microbiota. Conclusions: Our results reveal the degree to which a new, evolving symbiont can colonise and maintain its conferred phenotype (i.e., pathogen-resistance) with minimal disruption to the host microbiota diversity.

scholarly journals Microbiome responses in a novel nematode defensive symbiosis

2019 ◽  
Author(s):  
Dylan Dahan ◽  
Gail M. Preston ◽  
Jordan Sealey ◽  
Kayla C. King
Keyword(s):  
Species Interactions ◽  
Ecological Impacts ◽  
Protective Effects ◽  
Protective Properties ◽  
Minimal Impact ◽  
C Elegans ◽  
Defensive Symbiosis ◽  
Micro Organisms ◽  
Microbiota Diversity

Abstract Background Bacteria adapted to live within animals can protect their hosts against harmful infections. Beyond antagonism with parasites, a ‘defensive’ bacterial symbiont could engage in additional interactions with other colonizing micro-organisms. A single bacterium might thus have cascading ecological impacts on the whole microbiome that are rarely investigated. Here, we assess the role of a symbiont as a driver of host-associated microbiota composition by using an experimentally-adapted bacterium with protective properties ( Enterococcus faecalis ) inside a nematode host model ( Caenorhabditis elegans ).Results An analysis of 16S rRNA data from C. elegans exposed to E. faecalis and subsequently reared in soil, reveal that E. faecalis presence and adaptation to host environment had minimal impact on microbiota diversity. In addition, the protective effects of E. faecalis against opportunistic Staphylococcus aureus pathogens were still maintained despite multi-species interactions within the microbiota.Conclusions Our results reveal the degree to which a novel, evolving symbiont can colonise and maintain its conferred phenotype (i.e., parasite-resistance) with minimal change to the host microbiome.

scholarly journals THE IDENTIFICATION OF BACTERIAL SYMBIONT’S OF THE LARVAE ORYCTES RHINOCEROS L. AND THE ROLE OF THE BACTERIA IN COMPOSTING PROCESS

2018 ◽  
Vol 1 (2) ◽  
pp. 43 ◽  
Author(s):  
Octanina Sari Sijabat ◽  
Marheni Marheni ◽  
Darma Bakti
Keyword(s):  
16S Rrna ◽  
16S Rdna ◽  
Plant Material ◽  
Bacterial Species ◽  
Symbiotic Bacteria ◽  
Bacterial Symbionts ◽  
Speed Up ◽  
Hind Gut ◽  
Micro Organisms

AbstractOryctes rhinoceros L. has symbioses with micro organisms in their hind guts which further break down plant material consumed by beetle. The aim of this research is to determine the identification of the existence of the bacterial species in the hind gut larvae of the symbiotic bacteria using biochemical test and analysis based on 16S rRNA. The result of this research indicate that there were two different bacterials: Bacillus siamensis and Bacillus stratosphericus found. The bacteria was used for starting the composting and more specifically, the Bacillus siamensis can speed up composting with the end result at C/N 13.16.Keywords: Larvae O. rhinoceros L, Bacterial Symbionts, 16S rDNA, Composting

scholarly journals Evaluation of Enterococcus faecalis, Staphylococcus warneri and Staphylococcus aureus species in adults with generalized chronic periodontitis

2017 ◽  
Vol 65 (2) ◽  
pp. 121-127
Author(s):  
Aretuza FRITOLI ◽  
Eduardo LOBÃO ◽  
Geisla Soares ◽  
Belén RETAMAL-VALDES ◽  
Magda FERES
Keyword(s):  
Staphylococcus Aureus ◽  
Enterococcus Faecalis ◽  
Chronic Periodontitis ◽  
Bacterial Species ◽  
Hybridization Technique ◽  
Periodontal Pathogens ◽  
Periodontal Health ◽  
Staphylococcus Warneri ◽  
Percentage Points

ABSTRACT Objective: To identify and quantify the levels of three bacterial species that have recently been identified as potential “new” periodontal pathogens (Enterococcus faecalis, Staphylococcus aureus and Staphylococcus warneri) in subjects with periodontal health and generalized chronic periodontitis. Methods: Thirty adults with generalized chronic periodontitis and 10 periodontally healthy were included in this study. Nine subgingival biofilm samples were collected per subject and individually analyzed by checkerboard DNA-DNA hybridization technique. Results: The mean levels of E. faecalis and S. warneri were higher in chronic periodontitis than in periodontal health (p<0.05). Furthermore, a higher percentage of subjects with periodontitis were colonized by the three species evaluated in comparison with healthy subjects (p<0.05). This represented a difference of 40 percentage points between the two groups, for E. faecalis (present in 90% of individuals with periodontitis and 50% of the healthy individuals) and S. warneri (100% and 60%, respectively), and 26 percentage points for S. aureus (86% and 60%, respectively). Conclusion: E. faecalis and S. warneri have the potential to be periodontal pathogens. The role of S. aureus was less evident, since this species was more prevalent and at relatively higher levels in health than the other two species. These data might guide future studies on the role of these microorganisms in the etiology of periodontitis and help to establish more effective treatments for these infections.

scholarly journals Role of a qnr-Like Gene in the Intrinsic Resistance of Enterococcus faecalis to Fluoroquinolones

2007 ◽  
Vol 51 (9) ◽  
pp. 3254-3258 ◽  
Author(s):  
Stéphanie Arsène ◽  
Roland Leclercq
Keyword(s):  
Enterococcus Faecalis ◽  
Potential Role ◽  
Bacterial Species ◽  
Dna Gyrase ◽  
Fluoroquinolone Resistance ◽  
Multicopy Plasmid ◽  
Intrinsic Resistance ◽  
Repeat Protein ◽  
E Coli

ABSTRACT Fluoroquinolones are poorly active against enterococci. Recently, plasmid-borne resistance to fluoroquinolones due to the qnr gene was reported in members of the Enterobacteriaceae family. The gene encodes a pentapeptide repeat protein that protects DNA gyrase from inhibition by fluoroquinolones. We have identified in the genome of Enterococcus faecalis V583 a qnr-like gene, named E. faecalis qnr (qnr E. faecalis ), encoding a putative pentapeptide repeat protein that shares 25% identity with Qnr. To assess its potential role in the intrinsic resistance of E. faecalis to fluoroquinolones, qnr E. faecalis was inactivated in E. faecalis JH2-2 by insertion of the thermosensitive vector pG1KT. This strain was then complemented with qnr E. faecalis cloned in the multicopy plasmid pORI23. The effects of its overexpression were also studied. Inactivation of the qnr E. faecalis gene resulted in twofold decreases in the MICs of ofloxacin and ciprofloxacin. When the gene was complemented or overexpressed, MICs of fluoroquinolones increased four- to nine-fold, leading to MICs of ofloxacin and ciprofloxacin equal to 32 μg/ml and 8 μg/ml, respectively. The E. faecalis Qnr (Qnr E. faecalis ) protein was produced and purified. Qnr E. faecalis protein protected Escherichia coli DNA gyrase from inhibition by ofloxacin. The qnr E. faecalis gene was then introduced into E. coli DH10B, Staphylococcus aureus RN4220, and Lactococcus lactis IL-1419 to study its heterologous expression. MICs of the various fluoroquinolones tested increased 4- to 16-fold, showing that Qnr E. faecalis conferred resistance to fluoroquinolones in various bacterial backgrounds. Overexpression of qnr E. faecalis in enterococci or mobilization of the gene to other bacterial species may be anticipated as a possible new mechanism for fluoroquinolone resistance.

scholarly journals Virulence Effect of Enterococcus faecalis Protease Genes and the Quorum-Sensing Locus fsr in Caenorhabditis elegans and Mice

2002 ◽  
Vol 70 (10) ◽  
pp. 5647-5650 ◽  
Author(s):  
Costi D. Sifri ◽  
Eleftherios Mylonakis ◽  
Kavindra V. Singh ◽  
Xiang Qin ◽  
Danielle A. Garsin ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Quorum Sensing ◽  
Enterococcus Faecalis ◽  
Insertion Mutant ◽  
Extracellular Proteases ◽  
C Elegans ◽  
Related Proteins ◽  
Nematode Worm ◽  
Peritonitis Model

ABSTRACT The expression of two Enterococcus faecalis extracellular virulence-related proteins, gelatinase (GelE) and serine protease (SprE), has been shown to be positively regulated by the fsr quorum-sensing system. We recently developed a novel system for studying E. faecalis pathogenicity that involves killing of the nematode worm Caenorhabditis elegans and showed that an E. faecalis fsrB mutant (strain TX5266) exhibited attenuated killing. We explore here the role of the fsr/gelE-sprE locus in pathogenicity by comparing results obtained in the nematode system with a mouse peritonitis model of E. faecalis infection. Insertion mutants of fsrA (TX5240) and fsrC (TX5242), like fsrB (TX5266), were attenuated in their ability to kill C. elegans. A deletion mutant of gelE (TX5264) and an insertion mutant of sprE (TX5243) were also attenuated in C. elegans killing, although to a lesser extent than the fsr mutants. Complementation of fsrB (TX5266) with a 6-kb fragment containing the entire fsr locus restored virulence in both the nematode and the mouse peritonitis models. The fsr mutants were not impaired in their ability to colonize the nematode intestine. These data show that extracellular proteases and the quorum-sensing fsr system are important for E. faecalis virulence in two highly divergent hosts: nematodes and mice.

How do histone modifications contribute to transgenerational epigenetic inheritance in C. elegans?

2020 ◽  
Vol 48 (3) ◽  
pp. 1019-1034 ◽  
Author(s):  
Rachel M. Woodhouse ◽  
Alyson Ashe
Keyword(s):  
Histone Modifications ◽  
Molecular Mechanisms ◽  
Epigenetic Inheritance ◽  
Nematode Caenorhabditis Elegans ◽  
Histone Methyltransferases ◽  
Transgenerational Epigenetic Inheritance ◽  
C Elegans ◽  
Recent Developments ◽  
Gene Regulatory

Gene regulatory information can be inherited between generations in a phenomenon termed transgenerational epigenetic inheritance (TEI). While examples of TEI in many animals accumulate, the nematode Caenorhabditis elegans has proven particularly useful in investigating the underlying molecular mechanisms of this phenomenon. In C. elegans and other animals, the modification of histone proteins has emerged as a potential carrier and effector of transgenerational epigenetic information. In this review, we explore the contribution of histone modifications to TEI in C. elegans. We describe the role of repressive histone marks, histone methyltransferases, and associated chromatin factors in heritable gene silencing, and discuss recent developments and unanswered questions in how these factors integrate with other known TEI mechanisms. We also review the transgenerational effects of the manipulation of histone modifications on germline health and longevity.

Centrosome Aurora A gradient ensures single polarity axis in C. elegans embryos

2020 ◽  
Vol 48 (3) ◽  
pp. 1243-1253 ◽  
Author(s):  
Sukriti Kapoor ◽  
Sachin Kotak
Keyword(s):  
Symmetry Breaking ◽  
Cell Fate ◽  
Cell Cortex ◽  
Axis Formation ◽  
Aurora A Kinase ◽  
Aurora A ◽  
C Elegans ◽  
Cell Embryo ◽  
Polarity Establishment

Cellular asymmetries are vital for generating cell fate diversity during development and in stem cells. In the newly fertilized Caenorhabditis elegans embryo, centrosomes are responsible for polarity establishment, i.e. anterior–posterior body axis formation. The signal for polarity originates from the centrosomes and is transmitted to the cell cortex, where it disassembles the actomyosin network. This event leads to symmetry breaking and the establishment of distinct domains of evolutionarily conserved PAR proteins. However, the identity of an essential component that localizes to the centrosomes and promotes symmetry breaking was unknown. Recent work has uncovered that the loss of Aurora A kinase (AIR-1 in C. elegans and hereafter referred to as Aurora A) in the one-cell embryo disrupts stereotypical actomyosin-based cortical flows that occur at the time of polarity establishment. This misregulation of actomyosin flow dynamics results in the occurrence of two polarity axes. Notably, the role of Aurora A in ensuring a single polarity axis is independent of its well-established function in centrosome maturation. The mechanism by which Aurora A directs symmetry breaking is likely through direct regulation of Rho-dependent contractility. In this mini-review, we will discuss the unconventional role of Aurora A kinase in polarity establishment in C. elegans embryos and propose a refined model of centrosome-dependent symmetry breaking.

The role of intracanal medicaments in inhibition of bacteria isolated from root canals of infected primary molars

2019 ◽  
Vol 14 (1) ◽  
pp. 92
Author(s):  
Dr. Maha Abdul- Kareem Mahmood ◽  
Dr. Huda Elias Ali ◽  
Dr. Haraa Khairi Abdul-Kadher
Keyword(s):  
Antimicrobial Activity ◽  
Streptococcus Mutans ◽  
Normal Saline ◽  
Root Canal ◽  
Primary Teeth ◽  
Primary Molars ◽  
Root Canals ◽  
Etiologic Agents ◽  
Micro Organisms

Microbes are considered as the primary etiologic agents in endodontic diseases.Disinfection of the root canal is obtained by the combined effect of biomechanicalpreparation, irrigation and intra canal medicament. The aim of the present study wasto assess the antimicrobial activity of intracanal medicaments (formocresol andEndosepton) against two micro organisms (Streptococcus mutans and staphylococcusaureus) isolated from 15 necrotic pulps of primary molars indicated for pulpectomyprocedure. The samples were cultured, and purified using microbiological evaluation.Broth dilution test was performed in our study by preparing test tubes containing10 ml of BHI broth (pH. 7) which then inoculated with strains of the tested bacteriaand incubated at 37 C° for 24 h. After over night incubaction, ten fold dilution weremade in test tubes containing 9 ml of normal saline by adding 1 ml of the inoculum tothe first tube . Then from dilution 10-1 , 0.1 ml of cell suspension was added to 9.9 mlof formocresol and endosepton, then 0.1 ml was taken and spread on duplicates ofBHI agar plates at different intervals and incubated aerobically for 24 h. at 37 C°.Colonies on the plates were counted after incubation and CFU/mL (colony formingunit) was calculated. Our results indicating that there were no significant differencesbetween the intracanal medicaments, but there were high significant differencesbetween the intervals time of the study. We concluded that both materials had greatantibacterial effect against the pathogens commonly isolated from necrotic pulpaltissue of primary teeth.

Investigation on the antibacterial activity of electronic cigarette liquids (ECLs): a proof of concept study

2020 ◽  
Vol 21 ◽  
Author(s):  
Virginia Fuochi ◽  
Massimo Caruso ◽  
Rosalia Emma ◽  
Aldo Stivala ◽  
Riccardo Polosa ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Bacterial Species ◽  
A549 Cells ◽  
Bactericidal Effect ◽  
Minimal Bactericidal Concentration ◽  
Viability Assay ◽  
Dependent Inhibition ◽  
Dose Dependent Inhibition ◽  
Dose Dependent

Background: The key ingredients of e-cigarettes liquid are commonly propane-1,2-diol (also called propylene glycol) and propane-1,2,3-triol (vegetal glycerol) and their antimicrobial effects are already established. The nicotine and flavors which are often present in e-liquids can interfere with the growth of some microorganisms. Objective: The effect of the combining these elements in e-liquids is unknown. The aim of the study was to investigate the possible effects of these liquids on bacterial growth in the presence or absence of nicotine and flavors. Methods: Susceptibilities of pathogenic strains (Klebsiella pneumoniae, Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii, Escherichia coli, Enterococcus faecalis and Sarcina lutea) were studied by means of a multidisciplinary approach. Cell viability and antioxidant assays were also evaluated. Results: All e-liquids investigated showed antibacterial activity against at least one pathogenic strain. A higher activity was correlated to the presence of flavors and nicotine. Discussion: In most cases the value of minimal bactericidal concentration is equal to the value of minimal inhibitory concentration showing that these substances have a bactericidal effect. This effect was observed in concentrations up to 6.25% v/v. Antioxidant activity was also correlated to presence of flavors. Over time, the viability assay in human epithelial lung A549 cells showed a dose-dependent inhibition of cell growth. Conclusion: Our results have shown that flavors considerably enhance the antibacterial activity of propane-1,2-diol and propane-1,2,3-triol. This study provides important evidence that should be taken into consideration in further investigative approaches, to clarify the different sensitivity of the various bacterial species to e-liquids, including the respiratory microbiota, to highlight the possible role of flavors and nicotine.

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