Strote G et al. (1995) Parasitol Res "Ultrastructure study of the excretory system and the genital primordium of the infective stage of Onchocerca volvulus (Nematoda:Filarioidea)."

Bonow I, Strote G

[Parasitol Res, 1995]

The electron microscopic investigation of the anterior part of the infective third-stage juvenile of Onchocerca volvulus provides first insights into the structure of the excretory system of this developmental stage of the parasite. The most anterior part of this system consists of a cell process of the syncytial excretory cells. At this height the excretory cells enclose the cuticle-lined excretory channel. The channel is in the process of elongation in the anterior-posterior direction, indicated by cell division in this region. More posteriad an ampulla-like structure is forming in the cytoplasm of the excretory cells. The inner surface of this ampulla is lined with a small number of single microvilli. In this part of the system the cytoplasm of the excretory cells is rich in Golgi bodies and endocytic vesicles. The ampulla has direct access to the exterior by the excretory duct. The excretory duct is a cuticle-lined structure surrounded by supporting fibres of an additional cell. This duct cell connects the excretory duct to the body-wall cuticle at the excretory pore. Adjacent to the region of the excretory system a cell is found that resembles a gland cell. This cell is in close contact to the ventral nerve cord. The genital primordia of the third-stage juvenile consist of several dividing cells. The female genital primordium is seen at the junction of the muscular with the glandular oesophagus and the male primordium can be found at the junction of the glandular oesophagus with the gut.

Strote G et al. (1990) Trop Med Parasitol "Morphological alterations of male Onchocerca volvulus after in vitro exposure to mel w and milbemycin a confirming the results of viability tests."

Darge K, Bonow I, Strote G

[Trop Med Parasitol, 1990]

The suitability of two viability parameters used for screening of antifilarial activities of new compounds was examined by parallel observation of the morphology. Male Onchocerca volvulus were exposed in vitro to 10 mumol mel w and milbemycin a and examined by light and transmission electron microscopy. The viability was assessed by measurement of the motility, using a micromotility meter and by determination of tetrazolium reduction. Already twelve hours after exposure to mel w the muscles of the body wall showed severe damage. After 36 hours the other tissues revealed degenerative changes and after 60 hours disintegration of all tissues was observed. Effects on the morphology caused by milbemycin a were seen earliest after 60 hours. Condensed cytoplasm in the hypodermal layer and beginning degeneration of spermatogenic stages indicated drug activity. The time-point of appearance of these drug induced morphological alterations was in accordance with the decrease of the motility indices and the degree of tetrazolium reduction. Morphological alterations indicating irreversible damage of worm tissues are a reliable parameter to detect macrofilaricidal activity. The good agreement between the results of the morphological examination and the assessment of the motility and the tetrazolium reduction confirms the suitability of the latter two assays for in vitro drug screening with O. volvulus.

Souza ACR et al. (2018) Genes (Basel) "Pathogenesis of the Candida parapsilosis Complex in the Model Host Caenorhabditis elegans."

Fuchs BB, Mylonakis E, Colombo AL, Alves VS, Souza ACR, Jayamani E

[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.

Fourie R et al. (2021) Front Cell Infect Microbiol "Candida albicans SET3 Plays a Role in Early Biofilm Formation, Interaction With Pseudomonas aeruginosa and Virulence in Caenorhabditis elegans."

Gcilitshana O, Fourie R, Albertyn J, Sebolai O, Pohl CH

[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>

Strote G et al. (1997) Parasitol Res "The anterior central nervous system of male Onchocerca volvulus (Nematoda:Filarioidea) as a target for chemotherapy: results of an electron microscopy study."

Attah S, Strote G, Bonow I

[Parasitol Res, 1997]

An electron microscopy study was performed to evaluate the feasibility of the use of the anterior nerve ring of male Onchocerca volvulus for the assessment of early drug effects. Worms were exposed to new and known compounds at reasonable concentrations of 1 microM and less for 6, 12, 18, and 36 h in an established in vitro system. The anterior end of the filariae up to a length of 1 mm was examined and the morphological findings were compared with motility and reduction of a tetrazolium sat to formazan by live but not dead worms. The nerve fibers were more susceptible to the chemotherapeutic intervention then the other tissues in the anteriormost part of the worms. The alterations depended on the duration of exposure and the chemical nature of the compounds used. Morphological changes in the nervous tissue and the inhibition of motility and formazan production corresponded well for the arsenical mel w, used as an active standard, two pyrimidinyl-guanidines (PD 105482 and PD 105666), and an imidazolinylhydrazone (WR 251993).

Coomansingh-Springer C et al. (2019) Heliyon "Internal parasitic burdens in brown rats (Rattus norvegicus) from Grenada, West Indies."

Vishakha V, Acuna AM, Sharma RN, Coomansingh-Springer C, Armstrong E

[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.

Zhu Q et al. (2020) Oxid Med Cell Longev "A Dihydroflavonoid Naringin Extends the Lifespan of C. elegans and Delays the Progression of Aging-Related Diseases in PD/AD Models via DAF-16."

Zhou XG, Wu GS, Chen JN, Zhu Q, Qu Y, Luo HR

[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.

Wu CJ et al. (2019) Appl Environ Microbiol "Genotypic and Phenotypic Characteristics of Aeromonas Isolates from Fish and Patients in Tainan City."

Su YC, Lee NY, Chen PL, Ko WC, Li CW, Chen YW, Li MC, Wu CJ, Shu CY, Su SL, 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>_CphA, which encodes a carbapenemase, but only a minority (6.7%, 7/104) were nonsusceptible to carbapenem. Regarding AmpC -lactamase genes, <i>bla</i>_AQU-1 was exclusively found in <i>A. dhakensis</i> isolates and <i>bla</i>_MOX3 only in <i>A. caviae</i> isolates, but only 7.6% (6) of the 79 <i>Aeromonas</i> isolates carrying <i>bla</i>_AQU-1 or <i>bla</i>_MOX3 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.

Hariri S et al. (2023) MicroPubl Biol "53bp1 mutation enhances brca1 and bard1 embryonic lethality in C. elegans."

Li Q, Hariri S, Engebrecht J

[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.

Estrada-de Los Santos P et al. (2018) Genes (Basel) "Whole Genome Analyses Suggests that Burkholderia sensu lato Contains Two Additional Novel Genera (Mycetohabitans gen. nov., and Trinickia gen. nov.): Implications for the Evolution of Diazotrophy and Nodulation in the Burkholderiaceae."

Briscoe L, Dos Reis Junior FB, Steenkamp ET, Chavez-Ramirez B, Poole PS, Palmer M, Maluk M, Lafos M, Beukes C, Gross E, Humm E, Arrabit M, Whitman WB, Simon MF, James EK, Estrada-de Los Santos P, Venter SN, Khan N, Crook M, Hirsch AM, Shapiro N

[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>.