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

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

[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."

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

[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>

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

[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.

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

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

[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.

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

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>_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."

Engebrecht J, Hariri S, Li Q

[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.

Sun S et al. (2019) Biosci Microbiota Food Health "Toll-like receptor homolog TOL-1 regulates Bifidobacterium infantis-elicited longevity and behavior in Caenorhabditis elegans."

Komura T, Nishikawa Y, Mizuno Y, Kage-Nakadai E, Sun S

[Biosci Microbiota Food Health, 2019]

<i>Bifidobacterium infantis</i>, a Gram-positive bacterium, is one of the commonly used probiotics. We previously showed that <i>B. infantis</i> modified host defense systems and extended the lifespan of the nematode <i>Caenorhabditis elegans</i>. In the present study, we showed that the lifespan extension caused by <i>B. infantis</i> was enhanced in animals having a mutation in the <i>tol-1</i> gene that encodes the sole <i>C. elegans</i> homolog of Toll-like receptors (TLRs). Meanwhile, lifespan increased by other probiotic bacteria, such as <i>Bacillus subtilis</i> or <i>Clostridium butyricum</i>, was not affected in the <i>tol-1</i> mutant animals. A microarray analysis revealed that the expression of innate immune response-related genes was significantly increased in the <i>tol-1</i> mutant. Worms with the <i>tol-1</i> mutation exhibited reduced leaving behavior from the <i>B. infantis</i> lawn, while canonical downstream factors <i>trf-1</i>/TRAF and <i>ikb-1</i>/IB appeared to not be involved. In conclusion, <i>C. elegans tol-1</i>/TLR regulates <i>B. infantis</i>-induced longevity and also regulates behavior against <i>B. infantis</i>.

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."

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

Ding AJ et al. (2023) Front Immunol "Salmonella enterica serovar Paratyphi A-induced immune response in Caenorhabditis elegans depends on MAPK pathways and DAF-16."

Dong Y, Zhang WM, Liu XC, Ding AJ, Zeng WK, Ma HJ, He JB, Tao J, Pan SD, Chen B

[Front Immunol, 2023]

<i>Salmonella enterica</i> serovar Paratyphi A (<i>S</i>. Paratyphi A) is a pathogen that can cause enteric fever. According to the recent epidemic trends of typhoid fever, <i>S</i>. Paratyphi A has been the major important causative factor in paratyphoid fever. An effective vaccine for <i>S</i>. Paratyphi A has not been developed, which made it a tricky public health concern. Until now, how <i>S</i>. Paratyphi A interacts with organisms remain unknown. Here using lifespan assay, we found that <i>S</i>. Paratyphi A could infect <i>Caenorhabditis elegans</i> (<i>C. elegans</i>) at 25&#xb0;C, and attenuate thermotolerance. The immune response of <i>C. elegans</i> was mediated by <i>tir-1</i>, <i>nsy-1</i>, <i>sek-1</i>, <i>pmk-1</i>, <i>mpk-1</i>, <i>skn-1</i>, <i>daf-2</i> and <i>daf-16</i>, suggesting that <i>S</i>. Paratyphi A could regulate the MAPK and insulin pathways. Furthermore, we observed several phenotypical changes when <i>C. elegans</i> were fed <i>S</i>. Paratyphi A, including an accelerated decline in body movement, reduced the reproductive capacity, shortened spawning cycle, strong preference for OP50, arrested pharyngeal pumping and colonization of the intestinal lumen. The virulence of <i>S</i>. Paratyphi A requires living bacteria and is not mediated by secreting toxin. Using hydrogen peroxide analysis and quantitative RT-PCR, we discovered that <i>S</i>. Paratyphi A could increase oxidative stress and regulate the immune response in <i>C</i>. <i>elegans</i>. Our results sheds light on the infection mechanisms of <i>S</i>. Paratyphi A and lays a foundation for drugs and vaccine development.

Andrade G et al. (2020) J Fungi (Basel) "Brazilian Copaifera Species: Antifungal Activity against Clinically Relevant Candida Species, Cellular Target, and In Vivo Toxicity."

Scorzoni L, Bastos JK, Carvalho MTM, Mendes-Giannini MJS, Pires RH, Martins CHG, Orlando HCS, Veneziani RCS, Ambrosio SR, Andrade G, Abrao F, Pedroso RS

[J Fungi (Basel), 2020]

Plants belonging to the genus <i>Copaifera</i> are widely used in Brazil due to their antimicrobial properties, among others. The re-emergence of classic fungal diseases as a consequence of antifungal resistance to available drugs has stimulated the search for plant-based compounds with antifungal activity, especially against <i>Candida</i>. The <i>Candida</i>-infected <i>Caenorhabditis elegans</i> model was used to evaluate the in vitro antifungal potential of <i>Copaifera</i> leaf extracts and trunk oleoresins against <i>Candida</i> species. The <i>Copaifera</i> leaf extracts exhibited good antifungal activity against all <i>Candida</i> species, with MIC values ranging from 5.86 to 93.75 g/mL. Both the <i>Copaifera paupera</i> and <i>Copaifera reticulata</i> leaf extracts at 46.87 g/mL inhibited <i>Candida glabrata</i> biofilm formation and showed no toxicity to <i>C. elegans.</i> The survival of <i>C. glabrata</i>-infected nematodes increased at all the tested extract concentrations. Exposure to <i>Copaifera</i> leaf extracts markedly increased <i>C. glabrata</i> cell vacuolization and cell membrane damage. Therefore, <i>Copaifera</i> leaf extracts are potential candidates for the development of new and safe antifungal agents.