Gutteling EW et al. (2007) Heredity "Environmental influence on the genetic correlations between life-history traits in Caenorhabditis elegans."

Gutteling EW, Prokop Z, Riksen JA, Reszka J, Doroszuk A, Kammenga JE

[Heredity, 2007]

Empirical evidence is mounting to suggesting that genetic correlations between life-history traits are environment specific. However, detailed knowledge about the loci underlying genetic correlations in different environments is scant. Here, we studied the influence of temperature (12 degrees C and 24 degrees C) on the genetic correlations between egg size, egg number and body mass in the nematode Caenorhabditis elegans. We used a quantitative trait loci (QTL) approach based on a genetic map with evenly spaced single nucleotide polymorphism markers in an N2 x CB4856 recombinant inbred panel. Significant genetic correlations between various traits were found at both temperatures. We detected pleiotropic or closely linked QTL, which supported the negative correlation between egg size and egg number at 12 degrees C, the positive correlation across temperatures for body mass, and the positive correlation between body mass and egg size at 12 degrees C. The results indicate that specific loci control the covariation in these life-history traits and the locus control is prone to environmental conditions.Heredity advance online publication, 3 January 2007; doi:10.1038/sj.hdy.6800929.

Fukai R et al. (2016) J Hum Genet "De novo missense mutations in NALCN cause developmental and intellectual impairment with hypotonia."

Saitsu H, Kojima-Ishii K, Miyake N, Ihara K, Fukai R, Miyatake S, Masaaki S, Nakashima M, Torio M, Okamoto N, Chernuha V, Sakai Y, Tanaka F, Matsumoto N, Fattal-Valevski A, Kitai Y

[J Hum Genet, 2016]

Three recessive mutations in the sodium leak channel, nonselective (NALCN) have been reported to cause intellectual disability and hypotonia. In addition, 14 de novo heterozygous mutations have been identified in 15 patients with arthrogryposis and neurodevelopmental impairment. Here, we report three patients with neurodevelopmental disease and hypotonia, harboring one recurrent (p.R1181Q) and two novel mutations (p.L312V and p.V1020F) occurring de novo in NALCN. Mutation p.L312 is located in the pore forming S6 region of domain I and p.V1020F in the S5 region of domain III. Mutation p.R1181Q is in a linker region. Mapping these three mutations to a model of NALCN showed p.Leu312 and p.Val1020 positioned in the hydrophobic core of the pore modules, indicating these two mutations may affect the gating function of NALCN. Although p.R1181Q is unlikely to affect the ion channel structure, previous studies have shown that an analogous mutation in Caenorhabditis elegans produced a phenotype with a coiling locomotion, suggesting that p.R1181Q could also affect NALCN function. Our three patients showed profound intellectual disability and growth delay, facial dysmorphologies and hypotonia. The present data support previous work suggesting heterozygous NALCN mutations lead to syndromic neurodevelopmental impairment.Journal of Human Genetics advance online publication, 14 January 2016; doi:10.1038/jhg.2015.163.

Berg M et al. (2016) ISME J "Assembly of the Caenorhabditis elegans gut microbiota from diverse soil microbial environments."

Ho J, Alvarez-Cohen L, Wang A, Parke C, Shapira M, Berg M, Stenuit B, Knight M

[ISME J, 2016]

It is now well accepted that the gut microbiota contributes to our health. However, what determines the microbiota composition is still unclear. Whereas it might be expected that the intestinal niche would be dominant in shaping the microbiota, studies in vertebrates have repeatedly demonstrated dominant effects of external factors such as host diet and environmental microbial diversity. Hypothesizing that genetic variation may interfere with discerning contributions of host factors, we turned to Caenorhabditis elegans as a new model, offering the ability to work with genetically homogenous populations. Deep sequencing of 16S rDNA was used to characterize the (previously unknown) worm gut microbiota as assembled from diverse produce-enriched soil environments under laboratory conditions. Comparisons of worm microbiotas with those in their soil environment revealed that worm microbiotas resembled each other even when assembled from different microbial environments, and enabled defining a shared core gut microbiota. Community analyses indicated that species assortment in the worm gut was non-random and that assembly rules differed from those in their soil habitat, pointing at the importance of competitive interactions between gut-residing taxa. The data presented fills a gap in C. elegans biology. Furthermore, our results demonstrate a dominant contribution of the host niche in shaping the gut microbiota.The ISME Journal advance online publication, 22 January 2016; doi:10.1038/ismej.2015.253.

Obasuyi O et al. (2020) Microorganisms "Molecular Characterization and Pathogenicity of Staphylococcus aureus Isolated from Benin-City, Nigeria."

Oronsaye FE, Conly J, Zhang K, McClure J, Obasuyi O, Akerele JO

[Microorganisms, 2020]

While numerous studies examine the epidemiology and molecular characterization of <i>Staphylococcus aureus</i> in most developed countries, the detailed molecular characterization and molecular epidemiology of <i>S. aureus</i> strains and clones in Africa is lacking. We determined the molecular epidemiology and virulence of 81 non-duplicate isolates of <i>S. aureus</i> from Benin-City, Nigeria, collected during January-July 2016, and compared with global strains. Forty-seven isolates (58.0%) were found to be methicillin-sensitive <i>Staphylococcus aureus</i> (MSSA), while 34 (42.0%) were methicillin-resistant <i>Staphylococcus aureus</i> (MRSA). ST152-MSSA (24.7%) and ST7-MRSA-V (19.8%) were the dominant groups identified, which were not genetically related to global predominant strains, but rather exhibited regional dominance. An interesting finding of the study was the presence of highly related strains in the region, which differed primarily in their methicillin resistance gene carriage, staphylococcal cassette chromosome <i>mec</i> (SCC<i>mec</i>), with 99.4-99.7% relatedness between the genomes of the strains within the MRSA-MSSA pairs. This suggest that the strains within a pair are experiencing gain or loss of SCC<i>mec</i> within local conditions, with evolution continuing to diversify the strains to a small degree. This study represents the most comprehensive genetic and virulence study of <i>S. aureus</i> in Nigeria.

Steisslinger V et al. (2015) Vaccine "DNA vaccine encoding the moonlighting protein Onchocerca volvulus glyceraldehyde-3-phosphate dehydrogenase (Ov-GAPDH) leads to partial protection in a mouse model of human filariasis."

Steisslinger V, Erttmann KD, Brattig NW, Korten S

[Vaccine, 2015]

River blindness, caused by the filarial parasite Onchocerca volvulus, is a major socio-economic and public health problem in Sub-Saharan Africa. In January 2015, The Onchocerciasis Vaccine for Africa (TOVA) Initiative has been launched with the aim of providing new tools to complement mass drug administration (MDA) of ivermectin, thereby promoting elimination of onchocerciasis in Africa. In this context we here present Onchocerca volvulus glyceraldehyde-3-phosphate dehydrogenase (Ov-GAPDH) as a possible DNA vaccine candidate. We report that in a laboratory model for filariasis, immunization with Ov-GAPDH led to a significant reduction of adult worm load and microfilaraemia in BALB/c mice after challenge infection with the filarial parasite Litomosoides sigmodontis. Mice were either vaccinated with Ov-GAPDH.DNA plasmid (Ov-pGAPDH.DNA) alone or in combination with recombinantly expressed Ov-GAPDH protein (Ov-rGAPDH). During the following challenge infection of immunized and control mice with L. sigmodontis, those formulations which included the DNA plasmid, led to a significant reduction of adult worm loads (up to 57% median reduction) and microfilaraemia (up to 94% reduction) in immunized animals. In a further experiment, immunization with a mixture of four overlapping, synthetic Ov-GAPDH peptides (Ov-GAPDHpept), with alum as adjuvant, did not significantly reduce worm loads. Our results indicate that DNA vaccination with Ov-GAPDH has protective potential against filarial challenge infection in the mouse model. This suggests a transfer of the approach into the cattle Onchocerca ochengi model, where it is possible to investigate the effects of this vaccination in the context of a natural host-parasite relationship.

Chen PL et al. (2014) Clin Microbiol Infect "A comparative study of clinical Aeromonas dhakensis and Aeromonas hydrophila isolates in southern Taiwan: A. dhakensis is more predominant and virulent."

Chen CS, Ko WC, Chen PL, Tang HJ, Wu CJ, Tsai PJ

[Clin Microbiol Infect, 2014]

Aeromonas dhakensis, often phenotypically identified as Aeromonas hydrophila, is an important human pathogen. The present study aimed to compare the clinical and biological features of A. dhakensis and A. hydrophila isolates from human wounds. A total of 80 Aeromonas wound isolates collected between January 2004 and April 2011 were analysed. The species was identified by the DNA sequence matching of rpoD and gyrB (or rpoB if necessary). Most of the Aeromonas isolates were identified as A. dhakensis (37, 46.3%), and 13 (16.3%) as A. hydrophila. Both species alone can cause severe skin and soft-tissue infections. More A. dhakensis isolates were found in wounds exposed to environmental water (32.4% vs 0%, p 0.042). More biofilm formation was noted among A. dhakensis isolates (mean optical density at 570 nm, 1.23 +/- 0.09 vs 0.78 +/- 0.21, p 0.03). The MICs of ceftriaxone, imipenem and gentamicin for A. dhakensis isolates were higher (p &lt;0.0001, &lt;0.04, and &lt;0.01, respectively). The survival rates of Caenorhabditis elegans co-incubated with A. dhakensis from day 1 to day 3 were lower than those of worms infected with A. hydrophila in liquid toxicity assays (all p values &lt;0.01). Isolates of A. dhakensis exhibited more cytotoxicity, as measured by the released leucocyte lactate dehydrogenase levels in human normal skin fibroblast cell lines (29.6 +/- 1.2% vs 20.6 +/- 0.6%, p &lt;0.0001). The cytotoxin gene ast was primarily present in A. hydrophila isolates (100% vs 2.7%, p &lt;0.0001). In summary, A. dhakensis is the predominant species among Aeromonas wound isolates, and more virulent than A. hydrophila.

Yue-E H et al. (2016) Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi "[Meta regression analysis of five heavy metal biotoxicity effects onCaenorhabditis elegans]."

Yue-E H, Chao-Pin L, Nan Z

[Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi, 2016]

OBJECTIVE: To evaluate five heavy metal biotoxicity effects on Caenorhabditis elegans with Meta regression analysis. METHODS: The data were collected from the following electronic databases&#65306;PubMed, Web of Science, EBSCO, the Chinese Biomedical Database, Chinese National Knowledge Infrastructure, Wan Fang (Chinese) Databases and so on, and all updated through January 2004 to December 2014. A literature review was made on articles about Cd, Hg, Pb, As and Cr toxicity effects on C. elegans, and the data was extracted from figure information by Scan It software. A Meta regression model was built by stata12.0 software, using toxicity indices such as the dependent variables, and different metals, concentrations, exposure time, and development stages of C. elegans as independent variables. RESULTS:The study articles asociated with heavy metal biotoxicity effects on C. elegans were selected out, 10 studies of Cu, 12 studies of Cr, 12 studies of Pb, 12 studies of Cd, 3 studies of As and 14 studies of Hg. The mortality of toxicities of 5 heavy metals on C. elegans ranked Hg > Pb > Cr> Cd>As; the biotoxicity of the indexes of body size based on development, generational time based on reproductive toxicity, body bend frequencies, and head thrash frequencies based on neurotoxicity ranked Hg > Pb > Cr > Cd; the biotoxicity ranked Hg > Pb > Cr> Cd>As by LC50 indexes of toxicities of 5 heavy metals on C. elegans. The sensitivity analysis proved that the Meta regression model was reliable. CONCLUSIONS: The biotoxicities on C. elegans of Hg and Pb are stronger than Cr, Cd and As.

Bamber BA et al. (2005) Br J Pharmacol "The composition of the GABA receptor at the Caenorhabditis elegans neuromuscular junction."

Richmond JE, Bamber BA, Jorgensen EM, Otto JF

[Br J Pharmacol, 2005]

The unc-49 gene of the nematode Caenorhabditis elegans encodes three gamma-aminobutyric acid type A (GABA(A)) receptor subunits. Two of these, UNC-49B and UNC-49C, are expressed at high abundance and co-localize at the neuromuscular junction.The UNC-49B subunit is sufficient to form a GABA(A) receptor in vitro and in vivo. Furthermore, all loss-of-function unc-49 alleles lack functional UNC-49B. No mutations specifically inactivate UNC-49C. Thus, UNC-49C appears to be dispensable for receptor function; however, UNC-49C has been conserved among different nematode species, suggesting it plays a necessary role.To ascertain whether UNC-49C is part of the GABA(A) receptor in vivo, we performed patch-clamp electrophysiology on C. elegans muscle cells. Sensitivity to GABA, and to the antagonists picrotoxin and pregnenolone sulfate, matched the UNC-49B/C heteromer rather than the UNC-49B homomer, for both exogenous and synaptically-released GABA.The synaptic localization of UNC-49C requires the presence of UNC-49B, indicative of a physical association between the two subunits in vivo. Thus, the in vivo receptor is an UNC-49B/C heteromer.UNC-49C plays a negative modulatory role. Using the rapid ligand-exchange technique in vitro, we determined that UNC-49C causes accelerated receptor desensitization. Previously, UNC-49C was shown to reduce single-channel conductance in UNC-49B/C heteromers. Thus, the function of UNC-49B is to provide GABA responsiveness and localization to synapses, while the function of UNC-49C is to negatively modulate receptor function and precisely shape inhibitory postsynaptic currents.British Journal of Pharmacology advance online publication, 17 January 2005; doi:10.1038/sj.bjp.0706052.

Lavigne JP et al. (2008) Pathol Biol (Paris) "[Extended-spectrum beta-lactamases-producing Stenotrophomonas maltophilia strains: CTX-M enzymes detection and virulence study]"

Gaillard JB, Tichit C, Lecaillon E, Lavigne JP, Bourg G, Sotto A

[Pathol Biol (Paris), 2008]

OBJECTIVE: To study the beta-lactamases content of Stenotrophomonas maltophilia strains and to evaluate the virulence potential of these strains with the in vivo Caenorhabditis elegans model. METHODOLOGY: From 1st January 2006 to 31st December 2006, a monitoring programme to study multidrug resistant Gram-negative bacteria including extended-spectrum beta-lactamases (ESBL)-producing S. maltophilia was conducted at Nimes University Hospital and Perpignan Hospital. The ESBL production was confirmed by the double-disk synergy test using ceftazidime, cefotaxime and cefepime disks associated with clavulanic acid disk. The strains were characterized phenotypically (beta-lactamase[s] identification) and genotypically (pulsed-field gel electrophoresis, plasmid analysis) and evaluated for their virulence with the in vivo nematode C. elegans model (establishment of survival curves [LT50]). RESULTS: Twelve ESBL-producing S. maltophilia strains were isolated in eight patients (median age: 65 years+/-19) mainly during skin infections (41.7%). The ESBL content revealed the presence of four CTX-M-15-producing strains at the same patient. The analysis by ECP confirmed that the four strains were identical. The plasmid analysis demonstrated that the plasmid carrying CTX-M-15 in the worldwide clonal Escherichia coli O25-ST131 strain and S. maltophilia were different. The C. elegans model confirmed that S. maltophilia strains presented a low virulence potential (LT50=4.5days+/-0.5 according to the strains and nematode death in 10days+/-1) whatever their resistance. CONCLUSION: For the first time in France, a CTX-M-15-producing S. maltophilia strain has been identified. The in vivo model confirmed that these bacteria have a low potential virulence. However, these strains were isolated from "immunocompromised" and multihospital patients demonstrating the necessary monitoring of these patients. The CTX-M after diffusing in hospitals and community in E. coli strains seem to spread in other Gram-negative bacteria.

Minciullo PL et al. (2018) Allergy Asthma Proc "Association between urticaria and nematode infections."

Cascio A, Gangemi S, Minciullo PL

[Allergy Asthma Proc, 2018]

BACKGROUND: The association between parasites and urticaria was first suggested in the last century. A wide range, 0-75.4%, of the prevalence of parasitic infection has been reported with chronic urticaria (CU). Moreover, urticaria may be detected in patients with parasitosis. Nematodes are a type of helminth that infect hundreds of millions of people throughout the world. OBJECTIVE: The aim of this work was to collect and review the published studies and cases of urticaria associated with nematode infections. METHODS: A search of scientific literature data bases from January 1960 until May 2017 was carried out. RESULTS: Numerous nematode infections have been associated with urticaria and/or angioedema: Anisakis simplex, Ascaris species (spp.), Dirofilaria spp., Enterobius vermicularis, Gnathostoma spp., Loa loa, Mansonella streptocerca; Necator americanus, Onchocerca volvulus, Strongyloides stercoralis, Toxocara spp., Trichinella spp., and Wuchereria bancrofti. The pathogenesis of urticaria in these infections generally remains unexplained. In some cases, skin manifestations were caused by the presence of the worm in the skin (Filaria, Gnathostoma); in other cases, such as A. simplex and S. stercoralis infections, there was a clear immunoglobulin E-mediated mechanism that led to allergic reactions, and infection and allergy coexisted; for other nematodes, the association was anecdotal and only a few cases were reported. CONCLUSION: It is difficult to detect a certain causal effect, except when urticaria improves or disappears after infection treatment. Cases of isolated urticaria not associated with other symptoms rarely may be caused by helminths. In the current guideline for urticaria, parasitosis is considered to be a rare possible cause of CU in developed industrial countries, Therefore, although a routine screening of parasitic infection in CU is not recommended, in our opinion, testing a patient with urticaria for parasites is a physician's choice based on the characteristics of the patient, such as associated symptoms, dietary habit, provenance country and previous travel.