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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.
-
[
International C. elegans Meeting,
1979]
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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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[
Worm Breeder's Gazette,
1980]
Data presented at Cold Spring Harbor this year showed, that 200 and 400 g per ml precocene-2 in NGM food dramatically decrease the final size of
lon-2(
e678)/lon-2
(e678) hermaphrodites which were placed onto these plates at different ages. It was also demonstrated that the same doses proved to be toxic to the adults. Both effect could be partly compensated by different doses of methoprene to the food. Both the precocene and the JHA was more effective in higher concentrations, and we might suppose, that the precocene-'mini-adults' represent hypojuvenile hormone states. For to say it we need some more evidence. Following the life and growth of dauer larvae placed onto precocene and control plates we found that the molts happened almost the same time, but the size of animals on precocene plates hardly increased. By looking at them under a light microscope, these 'mini-adults' look like perfectly normal but small adults. John Sulston was so kind to observe some of our animals by Nomarski microscope and he also found them normal. Now we are looking for intermediate developing forms having both larval and adult cuticle, gonad and vulva structures. Excluding the possibility of the repellent/antifeeding effects of precocene, we found that when the worms have a choice of moving to bacteria with or without any of the drugs, they choose the latter. When they have to choose between JHA and precocene, they prefer JHA, but if they could avoid it, they don't lay eggs on it. (
e678 worms were used as dauers and scored as adults;
e1034 chemotactic mutant was the control.) Looking for chance for genetic differences in the reactions to precocene, we compared 22 mutant and N2 stocks on the base of adult test and found that one of the mutants resistant to levamisole proved to be highly resistant to precocene too. This mutant was isolated and generously provided by Jim Lewis: X37
(tmr3). We are going to isolate mutants resistant to precocene and also looking for developmentally intermediate forms among precocene 'mini- adults'.
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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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[
Gen Comp Endocrinol,
1982]
Precocene II causes a high adult mortality and a drastic growth reduction of growing Caenorhabditis elegans larvae. Symptoms caused by precocene II were partly reversible by the insect juvenile hormone analog methoprene, suggesting a physiological role of juvenile hormones in nematodes.
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Chen YW, Chen PL, Su YC, Li CW, Lin YT, Lee NY, Shu CY, Ko WC, Li MC, Su SL, Wu CJ
[
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.
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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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[
MicroPubl Biol,
2023]
In mice, mutation of <i>brca1</i> results in embryonic lethality, which is partially suppressed by <i>53bp1</i> mutation. In contrast, mutation of the <i>C. elegans</i> BRCA1 ortholog, <i>
brc-1 ,</i> or its binding partner, <i>
brd-1</i> , lead to only mild embryonic lethality. We show that in <i>C. elegans</i> , <i>
brc-1</i> and <i>
brd-1</i> embryonic lethality is enhanced when <i>53bp1</i> ortholog, <i>
hsr-9</i> , is also mutated. This is not a consequence of activating <i>
polq-1</i> -dependent microhomology-mediated end joining, as <i>
polq-1</i> mutation does not suppress embryonic lethality of <i>
hsr-9 ;
brc-1</i> mutants. Together, these results suggest that BRC-1 - BRD-1 and HSR-9 function in parallel pathways and do not act antagonistically as in mammals.
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Hirsch AM, Whitman WB, Gross E, Estrada-de Los Santos P, Simon MF, Briscoe L, Crook M, Shapiro N, Chavez-Ramirez B, Palmer M, Maluk M, Dos Reis Junior FB, Poole PS, Humm E, Beukes C, James EK, Khan N, Arrabit M, Lafos M, Venter SN, Steenkamp ET
[
Genes (Basel),
2018]
<i>Burkholderia</i> sensu lato is a large and complex group, containing pathogenic, phytopathogenic, symbiotic and non-symbiotic strains from a very wide range of environmental (soil, water, plants, fungi) and clinical (animal, human) habitats. Its taxonomy has been evaluated several times through the analysis of 16S rRNA sequences, concantenated 47 housekeeping gene sequences, and lately by genome sequences. Currently, the division of this group into <i>Burkholderia</i>, <i>Caballeronia, Paraburkholderia</i>, and <i>Robbsia</i> is strongly supported by genome analysis. These new genera broadly correspond to the various habitats/lifestyles of <i>Burkholderia</i> s.l., e.g., all the plant beneficial and environmental (PBE) strains are included in <i>Paraburkholderia</i> (which also includes all the N-fixing legume symbionts) and <i>Caballeronia</i>, while most of the human and animal pathogens are retained in <i>Burkholderia</i> sensu stricto. However, none of these genera can accommodate two important groups of species. One of these includes the closely related <i>Paraburkholderia rhizoxinica</i> and <i>Paraburkholderia endofungorum</i>, which are both symbionts of the fungal phytopathogen <i>Rhizopus microsporus</i>. The second group comprises the <i>Mimosa</i>-nodulating bacterium <i>Paraburkholderia symbiotica</i>, the phytopathogen <i>Paraburkholderia caryophylli</i>, and the soil bacteria <i>Burkholderia dabaoshanensis</i> and <i>Paraburkholderia soli</i>. In order to clarify their positions within <i>Burkholderia</i> sensu lato, a phylogenomic approach based on a maximum likelihood analysis of conserved genes from more than 100 <i>Burkholderia</i> sensu lato species was carried out. Additionally, the average nucleotide identity (ANI) and amino acid identity (AAI) were calculated. The data strongly supported the existence of two distinct and unique clades, which in fact sustain the description of two novel genera <i>Mycetohabitans</i> gen. nov. and <i>Trinickia</i> gen. nov. The newly proposed combinations are <i>Mycetohabitans endofungorum</i> comb. nov., <i>Mycetohabitans</i><i>rhizoxinica</i> comb. nov., <i>Trinickia caryophylli</i> comb. nov., <i>Trinickia</i><i>dabaoshanensis</i> comb. nov., <i>Trinickia soli</i> comb. nov., and <i>Trinickia</i><i>symbiotica</i> comb. nov. Given that the division between the genera that comprise <i>Burkholderia</i> s.l. in terms of their lifestyles is often complex, differential characteristics of the genomes of these new combinations were investigated. In addition, two important lifestyle-determining traits-diazotrophy and/or symbiotic nodulation, and pathogenesis-were analyzed in depth i.e., the phylogenetic positions of nitrogen fixation and nodulation genes in <i>Trinickia</i> via-a-vis other <i>Burkholderiaceae</i> were determined, and the possibility of pathogenesis in <i>Mycetohabitans</i> and <i>Trinickia</i> was tested by performing infection experiments on plants and the nematode <i>Caenorhabditis elegans</i>. It is concluded that (1) <i>T. symbiotica nif</i> and <i>nod</i> genes fit within the wider <i>Mimosa</i>-nodulating <i>Burkholderiaceae</i> but appear in separate clades and that <i>T. caryophylli</i><i>nif</i> genes are basal to the free-living <i>Burkholderia</i> s.l. strains, while with regard to pathogenesis (2) none of the <i>Mycetohabitans</i> and <i>Trinickia</i> strains tested are likely to be pathogenic, except for the known phytopathogen <i>T. caryophylli</i>.