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[
J Nematol,
1983]
Stage-specific differences in wheat germ agglutinin (WGA) binding saccharides were demonstrated between the surfaces of the eggs, L1 larvae, young aduhs, and old adults of Caenorhabditis elegans. The WGA binding was to n-acetylglucosamine groups but not to terminally linked n-acetylneuraminic acids. An age-related decrease in WGA binding occurred in adults, supporting previous findings of a decrease in net negative cuticle surface charge during aging.
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[
Exp Parasitol,
1990]
Complementary experiments were performed to indicate the presence or absence of sialic acids in axenically cultured Panagrellus redivivus and Caenorhabditis elegans. Competitive displacement experiments with radiolabeled Limax flavus agglutinin demonstrated the presence of sialic acid in nematodes grown in medium which contained liver extract as a growth factor but the absence of sialic acid when heme was substituted for liver extract. This finding suggested that sialic acid present in the liver medium was responsible for conflicting results of other studies. Transmission electron microscopy of thin sections from nematodes labeled with an LFA-ferritin conjugate revealed no label to the surface area of the cephalic chemosensilla. Fluorometric analysis with a modification of the thiobarbituric acid assay was negative for sialic acid. Analyses by gas chromatography-mass spectrometry, sensitive to the high picomole range, were also negative for sialic acid. Taken together the results provide evidence for the absence of sialic acid in P. redivivus and C. elegans using the most sensitive and diagnostic technique currently available.
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[
Genes (Basel),
2018]
<i>Caenorhabditis</i><i>elegans</i> is a valuable tool as an infection model toward the study of <i>Candida</i> species. In this work, we endeavored to develop a <i>C</i>. <i>elegans</i>-<i>Candida</i><i>parapsilosis</i> infection model by using the fungi as a food source. Three species of the C. parapsilosis complex (<i>C.</i><i>parapsilosis</i> (<i>sensu</i><i>stricto</i>), <i>Candida</i><i>orthopsilosis</i> and <i>Candida</i><i>metapsilosis</i>) caused infection resulting in <i>C. elegans</i> killing. All three strains that comprised the complex significantly diminished the nematode lifespan, indicating the virulence of the pathogens against the host. The infection process included invasion of the intestine and vulva which resulted in organ protrusion and hyphae formation. Importantly, hyphae formation at the vulva opening was not previously reported in <i>C</i>. <i>elegans</i>-<i>Candida</i> infections. Fungal infected worms in the liquid assay were susceptible to fluconazole and caspofungin and could be found to mount an immune response mediated through increased expression of <i>cnc</i>-<i>4</i>, <i>cnc</i>-<i>7</i>, and <i>fipr</i><i>-</i><i>22</i>/<i>23</i>. Overall, the <i>C</i>. <i>elegans</i>-<i>C</i>. <i>parapsilosis</i> infection model can be used to model <i>C</i>. <i>parapsilosis</i> host-pathogen interactions.
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[
Exp Parasitol,
1979]
The presence of galactose, glucose, mannose, and N-acetylglucosamine on the exposed surface of the nematodes Caenorhabditis briggsae and C. elegans was indicated by specific binding of three iodinated plant lectins. Proteolysis experiments suggested the absence of digestible glycoproteins on the exposed surfaces of the two nematode species. High resolution micrographs of cuticle surface preparations labeled with cationized ferritin indicated that the negative charge-bearing molecules are more densely packed on the nematode surface than on animal plasma membranes.
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[
International C. elegans Meeting,
1983]
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[
International C. elegans Meeting,
1989]
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[
Front Cell Infect Microbiol,
2021]
The yeast <i>Candida albicans</i> exhibits multiple morphologies dependent on environmental cues. <i>Candida albicans</i> biofilms are frequently polymicrobial, enabling interspecies interaction through proximity and contact. The interaction between <i>C. albicans</i> and the bacterium, <i>Pseudomonas aeruginosa</i>, is antagonistic <i>in vitro, with P. aeruginosa</i> repressing the yeast-to-hyphal switch in <i>C. albicans</i>. Previous transcriptional analysis of <i>C. albicans</i> in polymicrobial biofilms with <i>P. aeruginosa</i> revealed upregulation of genes involved in regulation of morphology and biofilm formation, including <i>SET3</i>, a component of the Set3/Hos2 histone deacetylase complex (Set3C). This prompted the question regarding the involvement of <i>SET3</i> in the interaction between <i>C. albicans</i> and <i>P. aeruginosa</i>, both <i>in vitro</i> and <i>in vivo.</i> We found that <i>SET3</i> may influence early biofilm formation by <i>C. albicans</i> and the interaction between <i>C. albicans</i> and <i>P. aeruginosa</i>. In addition, although deletion of <i>SET3</i> did not alter the morphology of <i>C. albicans</i> in the presence of <i>P. aeruginosa</i>, it did cause a reduction in virulence in a <i>Caenorhabditis elegans</i> infection model, even in the presence of <i>P. aeruginosa.</i>
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[
Oxid Med Cell Longev,
2020]
Naringin is a dihydroflavonoid, which is rich in several plant species used for herbal medicine. It has a wide range of biological activities, including antineoplastic, anti-inflammatory, antiphotoaging, and antioxidative activities. So it would be interesting to know if naringin has an effect on aging and aging-related diseases. We examined the effect of naringin on the aging of <i>Caenorhabditis elegans</i> (<i>C</i>. <i>elegans</i>). Our results showed that naringin could extend the lifespan of <i>C</i>. <i>elegans</i>. Moreover, naringin could also increase the thermal and oxidative stress tolerance, reduce the accumulation of lipofuscin, and delay the progress of aging-related diseases in <i>C</i>. <i>elegans</i> models of AD and PD. Naringin could not significantly extend the lifespan of long-lived mutants from genes in insulin/IGF-1 signaling (IIS) and nutrient-sensing pathways, such as <i>daf</i>-<i>2</i>, <i>akt</i>-<i>2</i>, <i>akt</i>-<i>1</i>, <i>eat</i>-<i>2</i>, <i>sir</i>-<i>2</i>.<i>1</i>, and <i>rsks</i>-<i>1</i>. Naringin treatment prolonged the lifespan of long-lived <i>glp</i>-<i>1</i> mutants, which have decreased reproductive stem cells. Naringin could not extend the lifespan of a null mutant of the fox-head transcription factor DAF-16. Moreover, naringin could increase the mRNA expression of genes regulated by <i>daf</i>-<i>16</i> and itself. In conclusion, we show that a natural product naringin could extend the lifespan of <i>C</i>. <i>elegans</i> and delay the progression of aging-related diseases in <i>C</i>. <i>elegans</i> models via DAF-16.
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[
Heliyon,
2019]
This study identified the endoparasites in Brown rat (<i>Rattus norvegicus)</i> during May to July 2017 in Grenada, West Indies. A total of 162 rats, 76 females and 86 males were trapped from St. George and St. David parishes in Grenada. The collected fecal samples were examined for parasitic eggs and/or oocysts using simple fecal flotation technique. Adult parasites found in the intestinal tract were examined for identification. The overall prevalence of intestinal parasites among rats was 79 %. Ten helminth species were recovered, several of which were reported for the first time in rodents in Grenada. The internal parasites consist of seven nematodes (<i>Angiostrongylus</i> spp., <i>Nippostrongylus braziliensis</i>, <i>Heterakis spumosa</i>, <i>Strongyloides ratti</i>, <i>Aspiculuris tetraptera</i>, <i>Syphacia</i> spp. and <i>Protospirura</i> spp.), one cestode (<i>Hymenolepsis diminuta</i>), one acanthocephalan (<i>Moniliformis moniliformis</i>) and one protozoa species (<i>Eimeria</i> spp.). The most prevalent zoonotic species were <i>Angiostrongylus</i> spp. (35.2%), <i>Hymenolepsis diminuta</i> (7.4%) and <i>Moniliformis moniliformis</i> (3.1%). Several nonzoonotic endoparasites; which included <i>Nippostrongylus braziliensis</i> (50.6%), <i>Heterakis spumosa</i> (15.4%), <i>Strongyloides ratti</i> (43.2%), <i>Aspiculuris tetraptera</i> (2.5%), <i>Syphacia</i> spp<i>.</i> (1.9%), <i>Protospirura</i> spp. (1.2%) and <i>Eimeria</i> spp. (4.7%) were also identified. The most prevalent parasites were <i>Nippostrongylus brasiliensis</i> (50.6%), <i>Strongyloides ratti</i> (43.2%) and <i>Angiostrongylus spp.</i> (35.2%). Co-infections occurred with up to six species per rat showing different combinations of parasitic infections.
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Shu CY, Li CW, Ko WC, Su YC, Chen YW, Lee NY, Su SL, Wu CJ, Chen PL, Li MC, Lin YT
[
Appl Environ Microbiol,
2019]
The present study aimed to isolate <i>Aeromonas</i> from fish sold in the markets as well as in sushi and seafood shops and compare their virulence factors and antimicrobial characteristics with those of clinical isolates. Among the 128 fish isolates and 47 clinical isolates, <i>A. caviae</i>, <i>A. dhakensis</i>, and <i>A. veronii</i> were the principal species. <i>A. dhakensis</i> isolates carried at least 5 virulence genes, more than other <i>Aeromonas</i> species. The predominant genotype of virulence genes was <i>hlyA/lip/alt/col/el</i> in both <i>A. dhakensis</i> and <i>A. hydrophila</i> isolates, <i>alt/col/ela</i> in <i>A. caviae</i> isolates, and <i>act</i> in <i>A. veronii</i> isolates. <i>A. dhakensis</i>, <i>A. hydrophila</i>, and <i>A. veronii</i> isolates more often exhibited hemolytic and proteolytic activity and showed greater virulence than <i>A. caviae</i> in <i>Caenorhabditis elegans</i> and the C2C12 cell line. However, the link between the genotypes and phenotypes of the studied virulence genes in <i>Aeromonas</i> species is not evident. Among the four major clinical <i>Aeromonas</i> species, nearly all (99.0%) <i>A. dhakensis</i>, <i>A. hydrophila</i>, and <i>A. veronii</i> isolates harbored <i>bla</i><sub>CphA</sub>, which encodes a carbapenemase, but only a minority (6.7%, 7/104) were nonsusceptible to carbapenem. Regarding AmpC -lactamase genes, <i>bla</i><sub>AQU-1</sub> was exclusively found in <i>A. dhakensis</i> isolates and <i>bla</i><sub>MOX3</sub> only in <i>A. caviae</i> isolates, but only 7.6% (6) of the 79 <i>Aeromonas</i> isolates carrying <i>bla</i><sub>AQU-1</sub> or <i>bla</i><sub>MOX3</sub> exhibited a cefotaxime resistance phenotype. In conclusion, fish <i>Aeromonas</i> isolates carry a variety of combinations of virulence and B-lactamase resistance genes and exhibit virulence phenotypes and antimicrobial resistance profiles similar to those of clinical isolates.<b>IMPORTANCE</b><i>Aeromonas</i> species can cause severe infections in immunocompromised individuals upon exposure to virulent pathogens in the environment, but the characteristics of environmental <i>Aeromonas</i> species remain unclear. Our study showed several pathogenic <i>Aeromonas</i> species possessing virulence traits and antimicrobial resistance similar to those of <i>Aeromonas</i> isolates causing clinical diseases were present in fish intended for human consumption in Tainan City.