scholarly journals Occurrence of Salmonella typhimurium resistance under sublethal/repeated exposure to cauliflower infusion and infection effects on Caernohabditis elegans host test organism

2019 ◽  
Vol 26 (2) ◽  
pp. 151-159
Author(s):  
Maria Sanz-Puig ◽  
Alejandra Arana-Lozano ◽  
M Consuelo Pina-Pérez ◽  
Pablo Fernández ◽  
Antonio Martínez ◽  
...  
Keyword(s):  
Food Industry ◽  
Research Work ◽  
Test Organism ◽  
Egg Laying ◽  
Repeated Exposure ◽  
Resistant Bacteria ◽  
Bacterial Cells ◽  
Natural Antimicrobial ◽  
C Elegans

Resistant bacteria to antimicrobials are increasingly emerging in medical, food industry and livestock environments. The present research work assesses the capability of Salmonella enterica var Typhimurium to become adapted under the exposure to a natural cauliflower antimicrobial by-product infusion in consecutive repeated exposure cycles. Caenorhabditis elegans was proposed as in vivo host-test organism to compare possible changes in the virulent pattern of the different rounds treated S. enterica var Typhimurium and untreated bacterial cells. According to the obtained results, S. enterica var Typhimurium was able to generate resistance against a repeated exposure to cauliflower by-product infusion 5% (w/v), increasing the resistance with the number of exposed repetitions. Meanwhile, at the first exposure, cauliflower by-product infusion was effective in reducing S. enterica var Typhimurium (≈1 log10 cycle), and S. enterica var Typhimurium became resistant to this natural antimicrobial after the second and third treatment-round and was able to grow (≈1 log10 cycle). In spite of the increased resistance observed for repeatedly treated bacteria, the present study reveals no changes on C. elegans infection effects between resistant and untreated S. enterica var Typhimurium, according to phenotypic parameters evaluation (lifespan duration and egg-laying).

scholarly journals New Antimicrobial Bioactivity against Multidrug-Resistant Gram-Positive Bacteria of Kinase Inhibitor IMD0354

Antibiotics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 665
Author(s):  
Iliana E Escobar ◽  
Alexis White ◽  
Wooseong Kim ◽  
Eleftherios Mylonakis
Keyword(s):  
Staphylococcus Aureus ◽  
Kinase Inhibitor ◽  
Cell Attachment ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Gram Positive ◽  
C Elegans ◽  
Vancomycin Resistant ◽  
High Concentrations

Multidrug-resistant pathogens pose a serious threat to human health. For decades, the antibiotic vancomycin has been a potent option when treating Gram-positive multidrug-resistant infections. Nonetheless, in recent decades, we have begun to see an increase in vancomycin-resistant bacteria. Here, we show that the nuclear factor-kappa B (NF-κB) inhibitor N-[3,5-Bis(trifluoromethyl)phenyl]-5-chloro-2-hydroxybenzamide (IMD0354) was identified as a positive hit through a Caenorhabditis elegans–methicillin-resistant Staphylococcus aureus (MRSA) infection screen. IMD0354 was a potent bacteriostatic drug capable of working at a minimal inhibitory concentration (MIC) as low as 0.06 µg/mL against various vancomycin-resistant strains. Interestingly, IMD0354 showed no hemolytic activity at concentrations as high as 16 µg/mL and is minimally toxic to C. elegans in vivo with 90% survival up to 64 µg/mL. In addition, we demonstrated that IMD0354′s mechanism of action at high concentrations is membrane permeabilization. Lastly, we found that IMD0354 is able to inhibit vancomycin-resistant Staphylococcus aureus (VRSA) initial cell attachment and biofilm formation at sub-MIC levels and above. Our work highlights that the NF-κB inhibitor IMD0354 has promising potential as a lead compound and an antimicrobial therapeutic candidate capable of combating multidrug-resistant bacteria.

In Vitro and In Vivo Efficacy of Catheters Impregnated With Antiseptics or Antibiotics: Evaluation of the Risk of Bacterial Resistance to the Antimicrobials in the Catheters

2001 ◽  
Vol 22 (10) ◽  
pp. 640-646 ◽  
Author(s):  
Lester A. Sampath ◽  
Suhas M. Tambe ◽  
Shanta M. Modak
Keyword(s):  
Bacterial Resistance ◽  
Test Organism ◽  
Similar Efficacy ◽  
Resistant Bacteria ◽  
Antibiotic Resistant ◽  
In Vivo Efficacy ◽  
Development Of Resistance ◽  
Zones Of Inhibition

AbstractObjective:To compare the efficacy of a new antiseptic catheter containing silver sulfadiazine and chlorhexidine on the external surface and chlorhexidine in the lumens to an antibiotic catheter impregnated with minocycline and rifampin on its external and luminal surfaces.Design:Experimental trial.Methods:Antimicrobial spectrum of catheters was determined by zones of inhibition. Resistance to luminal colonization was tested in vitro by locking catheter lumens withStaphylococcus epidermidisorStaphylococcus aureusculture after 7 days of perfusion. In vitro development of resistance to the antiseptic or antibiotic combination used in catheters was investigated. In vivo efficacy was tested (rat subcutaneous model) by challenge with sensitive or antibiotic-resistant bacteria.Results:Antiseptic and antibiotic catheters exhibited broad-spectrum action. However, antibiotic catheters were not effective againstCandidaspecies andPseudomonas aeruginosa.Both catheters prevented luminal colonization. Compared to controls, both test catheters resisted colonization when challenged withS aureus7 and 14 days' postimplant (P<.05).Repeated in vitro exposure ofS epidermidisculture to the antibiotic and antiseptic combinations led to small increases in the minimum inhibitory concentration (15 times and 2 times, respectively). Unlike the antibiotic catheter, the in vitro and in vivo activity of the antiseptic catheter was unaffected by the resistance profile of the test organism. Antiseptic catheters were more effective than antibiotic catheters in preventing colonization by rifampin-resistantS epidermidisin vivo (P<.05).Conclusions:Antiseptic and antibiotic catheters exhibit similar efficacy; however, when challenged with a rifampin-resistant strain, the antibiotic catheter appeared to be more susceptible to colonization than the antiseptic device.

Antimicrobial Effects of Silver Nanoparticles against Bacterial Cells Adhered to Stainless Steel Surfaces

2012 ◽  
Vol 75 (4) ◽  
pp. 701-705 ◽  
Author(s):  
EMILIANE A. ARAÚJO ◽  
NÉLIO J. ANDRADE ◽  
LUIS HENRIQUE M. da SILVA ◽  
PATRÍCIA C. BERNARDES ◽  
ÁLVARO V. N. de C. TEIXEIRA ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Stainless Steel ◽  
Food Industry ◽  
Antimicrobial Activities ◽  
New Method ◽  
Resistant Bacteria ◽  
Bacterial Cells ◽  
Antimicrobial Effects ◽  
Log Reduction ◽  
Steel Surfaces

Given the increasing number of antibiotic-resistant bacteria and the need to synthesize new antimicrobials, silver has attracted interest in the scientific community because of its recognized antimicrobial activity. This study aimed to evaluate the antimicrobial effects of silver nanoparticles (NP) obtained by a new method and tested at concentrations of 6 μg/ml and 60 μg/ml against the species Staphylococcus aureus, Listeria innocua, Salmonella Choleraesuis, Pseudomonas aeruginosa, Escherichia coli, and Bacillus cereus. The ability of these nanoparticles to remove or kill vegetative cells adhered to stainless steel surfaces was also evaluated. We observed that the NP obtained with the new method, concentrated silver nanoparticles (CNP), and silver nanoparticles with added sodium chloride (NPNaCl) had high antimicrobial activities (P &lt; 0.05). We also verified that the most effective condition for the removal of P. aeruginosa cells on stainless steel coupons (10 by 10 mm) was immersion of the surfaces in CNP. The CNP treatment produced a 5-log reduction of the microbial population after 30 to 60 min of immersion. The CNP treatment also performed better than water and sodium carbonate, a compound commonly applied in clean-in-place procedures in the food industry, in removing adherent B. cereus cells from stainless steel cylinders. Therefore, these results suggest that NP synthesized by a new procedure may be used as antimicrobials in the food industry, for example, for the sanitization of utensils that come into contact with foods.

scholarly journals Microfluidic Electric Egg-Laying Assay and Application to In-vivo Toxicity Screening of Microplastics using C. elegans

2021 ◽  
Author(s):  
Khaled Youssef ◽  
Daphne Archonta ◽  
Terrance J. Kubiseseki ◽  
Anurag Tandon ◽  
Pouya Rezai
Keyword(s):  
Environmental Pollutants ◽  
Egg Laying ◽  
Electric Signal ◽  
Data Sets ◽  
Toxicity Screening ◽  
C Elegans ◽  
Toxicological Studies ◽  
Individual Worm ◽  
Polystyrene Microparticles

AbstractEnvironmental pollutants like microplastics are posing health concerns on aquatic animals and the ecosystem. Microplastic toxicity studies using C. elegans as a model are evolving but methodologically hindered from obtaining statistically strong data sets, detecting toxicity effects based on microplastics uptake, and correlating physiological and behavioural effects at an individual-worm level. In this paper, we report a novel microfluidic electric egg-laying assay for phenotypical assessment of multiple worms in parallel. The effects of glucose and polystyrene microplastics at various concentrations on the worms’ electric egg-laying, length, diameter, and length contraction during exposure to electric signal were studied. The device contained eight parallel worm-dwelling microchannels called electric traps, with equivalent electrical fields, in which the worms were electrically stimulated for egg deposition and fluorescently imaged for assessment of neuronal and microplastic uptake expression. A new bidirectional stimulation technique was developed, and the device design was optimized to achieve a testing efficiency of 91.25%. Exposure of worms to 100mM glucose resulted in a significant reduction in their egg-laying and size. The effects of 1μm polystyrene microparticles at concentrations of 100 and 1000 mg/L on the electric egg-laying behaviour, size, and neurodegeneration of N2 and NW1229 (expressing GFP pan-neuronally) worms were also studied. Of the two concentrations, 1000 mg/L caused severe egg-laying deficiency and growth retardation as well as neurodegeneration. Additionally, using single-worm level phenotyping, we noticed intra-population variability in microplastics uptake and correlation with the above physiological and behavioural phenotypes, which was hidden in the population-averaged results. Taken together, these results suggest the appropriateness of our microfluidic assay for toxicological studies and for assessing the phenotypical heterogeneity in response to microplastics.

scholarly journals Probing the relationship between BTBD9 and MEIS1 in C. elegans and mouse

2020 ◽  
Vol 1 ◽  
Author(s):  
Shangru Lyu ◽  
Atbin Doroodchi ◽  
Yi Sheng ◽  
Mark P. DeAndrade ◽  
Youfeng Yang ◽  
...  
Keyword(s):  
Restless Legs Syndrome ◽  
Wheel Running ◽  
Egg Laying ◽  
Motor Deficit ◽  
Double Knockout ◽  
Genetic Studies ◽  
C Elegans ◽  
Increased Sensitivity ◽  
The Relationship

AbstractRestless legs syndrome (RLS) is a neurological disorder characterized by an urge to move and uncomfortable sensations. Genetic studies have identified polymorphisms in up to 19 risk loci, including MEIS1 and BTBD9. Rodents deficient in either homolog show RLS-like phenotypes. However, whether MEIS1 and BTBD9 interact in vivo is unclear. Here, with C. elegans, we observed that the hyperactive egg-laying behavior caused by loss of BTBD9 homolog was counteracted by knockdown of MEIS1 homolog. This was further investigated in mutant mice with Btbd9, Meis1, or both knocked out. The double knockout mice showed an earlier onset of the motor deficit in a wheel running test but did not have increased sensitivity to heat stimuli as observed in single knock outs. Meis1 protein level was not influenced by Btbd9 deficiency, and Btbd9 transcription was not affected by Meis1 haploinsufficiency. Our results demonstrate that MEIS1 and BTBD9 do not regulate each other.

scholarly journals The neural G protein Gαo tagged with GFP at an internal loop is functional in C. elegans

2021 ◽  
Author(s):  
Santosh Kumar ◽  
Andrew C Olson ◽  
Michael R Koelle
Keyword(s):  
Genetic Analysis ◽  
G Protein ◽  
Molecular Mechanisms ◽  
Fluorescent Protein ◽  
Protein Complexes ◽  
Egg Laying ◽  
Biochemical Purification ◽  
Internal Loop ◽  
C Elegans

Abstract Gαo is the alpha subunit of the major heterotrimeric G protein in neurons and mediates signaling by every known neurotransmitter, yet the signaling mechanisms activated by Gαo remain to be fully elucidated. Genetic analysis in Caenorhabditis elegans has shown that Gαo signaling inhibits neuronal activity and neurotransmitter release, but studies of the molecular mechanisms underlying these effects have been limited by lack of tools to complement genetic studies with other experimental approaches. Here we demonstrate that inserting the green fluorescent protein (GFP) into an internal loop of the Gαo protein results in a tagged protein that is functional in vivo and that facilitates cell biological and biochemical studies of Gαo. Transgenic expression of Gαo-GFP rescues the defects caused by loss of endogenous Gαo in assays of egg laying and locomotion behaviors. Defects in body morphology caused by loss of Gαo are also rescued by Gαo-GFP. The Gαo-GFP protein is localized to the plasma membrane of neurons, mimicking localization of endogenous Gαo. Using GFP as an epitope tag, Gαo-GFP can be immunoprecipitated from C. elegans lysates to purify Gαo protein complexes. The Gαo-GFP transgene reported in this study enables studies involving in vivo localization and biochemical purification of Gαo to complement the already well-developed genetic analysis of Gαo signaling.

scholarly journals Acetylcholine Signaling Genes are Required for Cocaine-Stimulated Egg Laying in Caenorhabditis elegans

2020 ◽  
Author(s):  
Soren Emerson ◽  
Megan Hay ◽  
Mark Smith ◽  
David Blauch ◽  
Nicole Snyder ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Nicotinic Acetylcholine Receptors ◽  
Intracellular Signaling ◽  
Acetylcholine Receptors ◽  
Egg Laying ◽  
Synthetic Enzymes ◽  
C Elegans ◽  
Degradative Enzymes ◽  
Serotonin Reuptake Transporter

Despite the toxicity and addictive liability associated with cocaine abuse, its mode of action is not completely understood, and effective pharmacotherapeutic interventions remain elusive. The cholinergic effects of cocaine on acetylcholine receptors, synthetic enzymes, and degradative enzymes have been the focus of relatively little empirical investigation. Due to its genetic tractability and anatomical simplicity, the egg laying circuit of the hermaphroditic nematode, Caenorhabditis elegans, is a powerful model system to precisely examine the genetic and molecular targets of cocaine in vivo. Here, we report a novel cocaine-induced phenotype in Caenorhabditis elegans, cocaine-stimulated egg laying. In addition, we present the results of an in vivo candidate screen of synthetic enzymes, receptors, degradative enzymes, and downstream components of the intracellular signaling cascades of the main neurotransmitter systems that control Caenorhabditis elegans egg laying. Our results show that cocaine-stimulated egg laying is dependent on acetylcholine synthesis and synaptic release, functional nicotinic acetylcholine receptors, and the Caenorhabditis elegans acetylcholinesterases. Further, we show that cocaine-stimulated egg laying is not dependent on other neurotransmitters besides acetylcholine, including serotonin, dopamine, octopamine, and tyramine. Finally, our data show that cocaine-stimulated egg laying is increased in mutants for the C. elegans serotonin reuptake transporter as well as mutants for a 5-HT-gated chloride channel likely expressed in the locomotion circuit. Together, these results highlight serotonergic inhibition of egg laying behavior, functional connectivity between the egg laying and locomotion circuits in Caenorhabditis elegans, and possible discrete cholinergic and serotonergic effects of cocaine in the egg laying and locomotion circuits, respectively.

Identified neurons in C. elegans coexpress vesicular transporters for acetylcholine and monoamines

2001 ◽  
Vol 280 (6) ◽  
pp. C1616-C1622 ◽  
Author(s):  
Janet S. Duerr ◽  
Jennifer Gaskin ◽  
James B. Rand
Keyword(s):  
Motor Neurons ◽  
Choline Acetyltransferase ◽  
Egg Laying ◽  
Vesicular Acetylcholine Transporter ◽  
Vesicular Monoamine Transporter ◽  
Monoamine Transporter ◽  
C Elegans ◽  
Vesicular Transporters ◽  
The Individual

We have identified four neurons (VC4, VC5, HSNL, HSNR) in Caenorhabditis elegans adult hermaphrodites that express both the vesicular acetylcholine transporter and the vesicular monoamine transporter. All four of these cells are motor neurons that innervate the egg-laying muscles of the vulva. In addition, they all express choline acetyltransferase, the synthetic enzyme for acetylcholine. The distributions of the vesicular acetylcholine transporter and the vesicular monoamine transporter are not identical within the individual cells. In mutants deficient for either of these transporters, there is no apparent compensatory change in the expression of the remaining transporter. This is the first report of neurons that express two different vesicular neurotransmitter transporters in vivo.

scholarly journals Phytobacter diazotrophicus from Intestine of Caenorhabditis elegans Confers Colonization-Resistance against Bacillus nematocida Using Flagellin (FliC) as an Inhibition Factor

Pathogens ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 82
Author(s):  
Qiuhong Niu ◽  
Suyao Liu ◽  
Mingshen Yin ◽  
Shengwei Lei ◽  
Fabio Rezzonico ◽  
...  
Keyword(s):  
Cell Division ◽  
Caenorhabditis Elegans ◽  
Membrane Protein ◽  
Bacterial Cells ◽  
Colonization Resistance ◽  
Flic Gene ◽  
C Elegans ◽  
Free Living Nematode ◽  
Bacterium Bacillus

Symbiotic microorganisms in the intestinal tract can influence the general fitness of their hosts and contribute to protecting them against invading pathogens. In this study, we obtained isolate Phytobacter diazotrophicus SCO41 from the gut of free-living nematode Caenorhabditis elegans that displayed strong colonization-resistance against invading biocontrol bacterium Bacillus nematocida B16. The colonization-resistance phenotype was found to be mediated by a 37-kDa extracellular protein that was identified as flagellin (FliC). With the help of genome information, the fliC gene was cloned and heterologously expressed in E. coli. It could be shown that the B. nematocida B16 grows in chains rather than in planktonic form in the presence of FliC. Scanning Electronic Microscopy results showed that protein FliC-treated B16 bacterial cells are thinner and longer than normal cells. Localization experiments confirmed that the protein FliC is localized in both the cytoplasm and the cell membrane of B16 strain, in the latter especially at the position of cell division. ZDOCK analysis showed that FliC could bind with serine/threonine protein kinase, membrane protein insertase YidC and redox membrane protein CydB. It was inferred that FliC interferes with cell division of B. nematocidal B16, therefore inhibiting its colonization of C. elegans intestines in vivo. The isolation of P. diazotrophicus as part of the gut microbiome of C. elegans not only provides interesting insights about the lifestyle of this nitrogen-fixing bacterium, but also reveals how the composition of the natural gut microbiota of nematodes can affect biological control efforts by protecting the host from its natural enemies.

scholarly journals Neuropeptides encoded by nlp-49 modulate locomotion, arousal and egg-laying behaviours in Caenorhabditis elegans via the receptor SEB-3

2018 ◽  
Vol 373 (1758) ◽  
pp. 20170368 ◽  
Author(s):  
Yee Lian Chew ◽  
Laura J. Grundy ◽  
André E. X. Brown ◽  
Isabel Beets ◽  
William R. Schafer
Keyword(s):  
Caenorhabditis Elegans ◽  
Egg Laying ◽  
Electrical Synapse ◽  
C Elegans ◽  
Neuronal Communication ◽  
Movement Dynamics ◽  
Evolutionarily Conserved ◽  
Genes Encoding ◽  
High Content Analysis

Neuropeptide signalling has been implicated in a wide variety of biological processes in diverse organisms, from invertebrates to humans. The Caenorhabditis elegans genome has at least 154 neuropeptide precursor genes, encoding over 300 bioactive peptides. These neuromodulators are thought to largely signal beyond ‘wired’ chemical/electrical synapse connections, therefore creating a ‘wireless’ network for neuronal communication. Here, we investigated how behavioural states are affected by neuropeptide signalling through the G protein-coupled receptor SEB-3, which belongs to a bilaterian family of orphan secretin receptors. Using reverse pharmacology, we identified the neuropeptide NLP-49 as a ligand of this evolutionarily conserved neuropeptide receptor. Our findings demonstrate novel roles for NLP-49 and SEB-3 in locomotion, arousal and egg-laying. Specifically, high-content analysis of locomotor behaviour indicates that seb-3 and nlp-49 deletion mutants cause remarkably similar abnormalities in movement dynamics, which are reversed by overexpression of wild-type transgenes. Overexpression of NLP-49 in AVK interneurons leads to heightened locomotor arousal, an effect that is dependent on seb-3. Finally, seb-3 and nlp-49 mutants also show constitutive egg-laying in liquid medium and alter the temporal pattern of egg-laying in similar ways. Together, these results provide in vivo evidence that NLP-49 peptides act through SEB-3 to modulate behaviour, and highlight the importance of neuropeptide signalling in the control of behavioural states. This article is part of a discussion meeting issue ‘Connectome to behaviour: modelling C. elegans at cellular resolution’.

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