Whole-body Extracts Research Articles

Allergen immunotherapy using recombinant Culicoides allergens improves clinical signs of equine insect bite hypersensitivity.

Insect bite hypersensitivity (IBH) is an IgE-mediated allergic dermatitis of horses caused by bites of Culicoides spp., sharing some common features with human atopic dermatitis. Allergen immunotherapy (AIT) using Culicoides whole-body extracts has limited efficacy. This study aimed to evaluate AIT with a pool of major Culicoides recombinant allergens in a prospective, double-blinded, placebo-controlled study. The IBH lesion score was assessed during a pre-treatment year and first treatment year (May-October) in 17 horses and in May and July of a second treatment year. Nine horses were immunized subcutaneously 3× with a combination of nine r-allergens (20 μg each/injection) in alum and monophosphoryl lipid A (MPLA). Eight horses received a placebo. The immunization was repeated twice the following year. The specific antibody response to one of the AIT Culicoides r-allergens was assessed. In the first treatment year, the decrease in average IBH lesion score was significantly larger in the AIT compared to the placebo group, with 67% of the AIT group and 25% of the placebo horses reaching >50% improvement of the average IBH lesion score. The response to the AIT was enhanced in the 2nd treatment year when 89% of the AIT vs. 14% of the placebo horses showed an improvement (p ≤ 0.01). IgG antibodies of all subclasses were induced, with IgG4/7 showing the most significant differences between groups. The post-AIT sera showed IgE blocking activity. AIT using only a few injections of small amounts of r-allergens in alum and MPLA as immunomodulators seems a promising approach for the treatment of insect bite allergy.

Stinging Ant Anaphylaxis: Advances in Diagnosis and Treatment

Stinging ants represent a wide range of over 200 different species across the world, of which Solenopsis, Myrmecia, Pogonomyrmex, and Brachyponera genera, account for a substantial economic and healthcare burden. S. invicta (red imported fire ant; IFA) and M. pilosula (jack jumper ant; JJA) are 2 species of high clinical importance, known to cause anaphylaxis in humans, with numerous reported fatalities. Diagnostic testing should be performed in patients with a history of a systemic reaction with skin testing and/or in vitro specific-IgE testing. In vitro testing is commercially available for IFA through whole-body extract (WBE) specific-IgE and JJA venom specific-IgE, but not widely available for other stinging ant species. Commercial venom component testing for IFA and JJA is currently not available. Patients with a clinical history and positive specific-IgE testing, should undergo treatment with specific immunotherapy, which is currently available for IFA and JJA. Build-up may be performed using conventional, semi-rush, rush, or ultra-rush schedules with similar risk profiles for IFA. Optimal duration for WBE immunotherapy for IFA and specific JJA venom immunotherapy is not well-studied, but generally recommended for at least 3-5 years. Sting challenges are used in research settings, primarily to assess treatment efficacy of immunotherapy.

Identification, synthesis, and field evaluation of components of the female-produced sex pheromone of Helopeltis cinchonae (Hemiptera: Miridae), an emerging pest of tea.

Helopeltis cinchonae (Hemiptera: Miridae) is a major pest of tea plantations in Asia. Conventional control of pests with pesticides is unsustainable. Therefore, safe and eco-friendly alternatives, such as pheromones, are required to manage the pest. In gas chromatography-electroantennographic detection (GC-EAD) analysis of whole-body extracts of virgin female H. cinchonae, two compounds elicited electroantennogram (EAG) responses from male antennae. These were identified as hexyl (R)-3-acetoxybutyrate and (R)-1-acetoxy-5-butyroxyhexane using gas chromatography-mass spectrometry (GC-MS) analysis compared to synthetic compounds. This is the first study to report 1-acetoxy-5-butyroxyhexane as an insect pheromone component. The synthetic compounds elicited dose-dependent EAG responses from the antennae of male H. cinchonae. In two field trapping experiments, the individual compounds were highly attractive to male H. cinchonae when dispensed from polyethylene vials. However, higher catches were obtained with blends of the two compounds in a 1:10 ratio. The blend of racemic compounds was as attractive as the blend of (R)-enantiomers. We reported that 1-acetoxy-5-butyroxyhexane and hexyl 3-acetoxybutyrate are components of the female-produced sex pheromone of H. cinchonae, but further work is required on the blend and loading of pheromone and on trap design to provide an optimized system for monitoring and control of this pest. The results may also facilitate the identification of the pheromones of other Helopeltis species, which are major pests in many crops. © 2024 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Brute force prey metabarcoding to explore the diets of small invertebrates.

Prey metabarcoding has become a popular tool in molecular ecology for resolving trophic interactions at high resolution, from various sample types and animals. To date, most predator-prey studies of small-sized animals (<1 mm) have met the problem of overabundant predator DNA in dietary samples by adding blocking primers/peptide nucleic acids. These primers aim to limit the PCR amplification and detection of the predator DNA but may introduce bias to the prey composition identified by interacting with sequences that are similar to those of the predator. Here we demonstrate the use of an alternative method to explore the prey of small marine copepods using whole-body DNA extracts and deep, brute force metabarcoding of an 18S rDNA fragment. After processing and curating raw data from two sequencing runs of varying depths (0.4 and 5.4 billion raw reads), we isolated 1.3 and 52.2 million prey reads, with average depths of ~15,900 and ~120,000 prey reads per copepod individual, respectively. While data from both sequencing runs were sufficient to distinguish dietary compositions from disparate seasons, locations, and copepod species, greater sequencing depth led to better separation of clusters. As computation and sequencing are becoming ever more powerful and affordable, we expect the brute force approach to become a general standard for prey metabarcoding, as it offers a simple and affordable solution to consumers that is impractical to dissect or unknown to science.

Reactividad IgE de sueros en pacientes con enfermedades autoinmunes, frente a una proteína multi-epítopes construida a partir de epítopes T de alérgenos de Ascaris lumbricoides

Background: Helminth infections for Ascaris lumbricoides and exposure to mite allergens stimulate a Th2 immune response present in allergic diseases. Helminth proteins are well known can modulate the host immune response and lessen the inflammation response. We evaluate the Ig E reactivity to a molecule constructed from A. lumbricoides T epitopes (MP1) in sera from patients suffering from T1D, LN, and JIA Methods: We designed and expressed a synthetic multi-epítope protein named MP1 from A. lumbricoides and house dust mites allergens. By indirect ELISA, we evaluated IgE-reactivity to MP1 and to the whole-body extract of Ascaris lumbricoidesin 45 sera from Colombian Caribbean patients with lupus nephritis (LN; n=25), type 1 diabetes (T1D; n=10) and Juvenil idiopathic arthritis (JIA; n=10). Individuals with poly autoimmunity were excluded. All patients were referred to the study by their specialist doctor. Results: IgE to whole-body extract of A. lumbricoides showed the following median concentrations: 484.2 ng/ml (IQR: 203.4) in JIA patients, 325.6 ng/ml (IQR: 179.3) in individuals with LN, and 424.7 ng/ml (IQR: 80.1) in T1D group. On the other hand, IgE-reactivity to MP1 was 126.4 ng/ml (IQR: 90.9) in JIA patients, 130.7 ng/ml (IQR: 94.8) in an individual with LN, and 148.8 ng/ml (IQR: 102.1) in T1D group. Although no statistical differences were observed between patient groups, the IgE to MP1 in all patients (n: 45) (IgE median: 134.2 ng/ml; IQR: 100) were significantly less compared to Ascaris extract (IgE median: 380.7 ng/ml; IQR: 175.8); (W:0.732; p-value: 1.034x10-7). Conclusions: These preliminary results suggest that MP1 showed antigenic properties with low IgE-reactivity compared to Ascaris lumbricoides extract in individuals with autoimmune diseases. Further studies are needed to understand better the immune response induced by this molecule.

Impact of diapause on the cuticular hydrocarbons and physiological status of Hippodamia variegata.

The spotted amber ladybird, Hippodamia variegata (Goeze) (Coleoptera: Coccinellidae), is known to be a potent predator of aphids, psyllids, whiteflies, mealybugs, and some butterfly species. This ladybeetle overwinters in the diapausing adult stage. The current study aimed to evaluate the impact of diapause on the energy resources and cuticular hydrocarbons (CHCs) of the female ladybeetle, specifically comparing the changes in glycogen, lipid, and protein contents, and CHCs profile of diapausing and non-diapausing adults. In this study, gas chromatography-mass was used to analyze whole-body extracts of the beetles. Results showed no significant differences between the amount of glycogen, lipid, and protein contents of diapausing and non-diapausing ladybeetle. The CHCs profile of H. variegata consisted of 24 hydrocarbons categorized into 2 groups: linear aliphatic hydrocarbons (n-alkanes) and methyl-branched hydrocarbons (17 molecules), as well as unsaturated cyclic compounds (7 molecules). The n-alkanes, with 14 compounds, were identified as the primary constituents of the CHCs of the ladybeetle. Six molecules were common to non-diapausing and diapausing beetles, 5 were exclusive to non-diapausing beetles, and 13 were exclusive to diapausing beetles. Moreover, we noted a significant difference in the quantity and quality of CHCs between diapausing and non-diapausing beetles, with diapausing beetles synthesizing more CHCs with longer chains. This disparity in CHC profiles was concluded to be an adaptation of H. variegata to survive harsh environmental conditions during diapause.

Eobania vermiculata whole-body muscle extract-loaded chitosan nanoparticles enhanced skin regeneration and decreased pro-inflammatory cytokines in vivo

BackgroundUsually, wounds recover in four to six weeks. Wounds that take longer time than this to heal are referred to as chronic wounds. Impaired healing can be caused by several circumstances like hypoxia, microbial colonization, deficiency of blood flow, reperfusion damage, abnormal cellular reaction and deficiencies in collagen production. Treatment of wounds can be enhanced through systemic injection of the antibacterial drugs and/or other topical applications of medications. However, there are a number of disadvantages to these techniques, including the limited or insufficient medication penetration into the underlying skin tissue and the development of bacterial resistance with repeated antibiotic treatment. One of the more recent treatment options may involve using nanotherapeutics in combination with naturally occurring biological components, such as snail extracts (SE). In this investigation, chitosan nanoparticles (CS NPs) were loaded with an Eobania vermiculata whole-body muscle extract. The safety of the synthesized NPs was investigated in vitro to determine if these NPs might be utilized to treat full-skin induced wounds in vivo.ResultsSEM and TEM images showed uniformly distributed, spherical, smooth prepared CS NPs and snail extract-loaded chitosan nanoparticles (SE-CS NPs) with size ranges of 76–81 and 91–95 nm, respectively. The zeta potential of the synthesized SE-CS NPs was − 24.5 mV, while that of the CS NPs was 25 mV. SE-CS NPs showed a remarkable, in vitro, antioxidant, anti-inflammatory and antimicrobial activities. Successfully, SE-CS NPs (50 mg/kg) reduced the oxidative stress marker (malondialdehyde), reduced inflammation, increased the levels of the antioxidant enzymes (superoxide dismutase and glutathione), and assisted the healing of induced wounds. SE-CS NPs (50 mg/kg) can be recommended to treat induced wounds safely. SE was composed of a collection of several wound healing bioactive components [fatty acids, amino acids, minerals and vitamins) that were loaded on CS NPs.ConclusionsThe nanostructure enabled bioactive SE components to pass through cell membranes and exhibit their antioxidant and anti-inflammatory actions, accelerating the healing process of wounds. Finally, it is advised to treat rats’ wounds with SE-CS NPs.Graphical abstract

Isolation of Extracellular Vesicles of Holothuria (Sea Cucumber Eupentacta fraudatrix).

Extracellular vesicles (EVs), carriers of molecular signals, are considered a critical link in maintaining homeostasis in mammals. Currently, there is growing interest in studying the role of EVs, including exosomes (subpopulation of EVs), in animals of other evolutionary levels, including marine invertebrates. We have studied the possibility of obtaining appropriate preparations of EVs from whole-body extract of holothuria Eupentacta fraudatrix using a standard combination of centrifugation and ultracentrifugation. However, the preparations were heavily polluted, which did not allow us to conclude that they contained vesicles. Subsequent purification by FLX gel filtration significantly reduced the pollution but did not increase vesicle concentration to a necessary level. To detect EVs presence in the body of holothurians, we used transmission electron microscopy of ultrathin sections. Late endosomes, producing the exosomes, were found in the cells of the coelom epithelium covering the gonad, digestive tube and respiratory tree, as well as in the parenchyma cells of these organs. The study of purified homogenates of these organs revealed vesicles (30-100 nm) morphologically corresponding to exosomes. Thus, we can say for sure that holothurian cells produce EVs including exosomes, which can be isolated from homogenates of visceral organs.

Entomotherapeutic Role of Periplaneta americana Extract in Alleviating Aluminum Oxide Nanoparticles-Induced Testicular Oxidative Impairment in Migratory Locusts (Locusta migratoria) as an Ecotoxicological Model

In this study, we shed light for the first time on the usage of migratory locusts (Locusta migratoria) as an insect model to investigate the nanotoxicological influence of aluminum oxide (Al2O3) nanoparticles at low doses on testes, and evaluate the capacity of a whole-body extract of American cockroaches (Periplaneta americana) (PAE) to attenuate Al2O3 NPs-induced toxicity. Energy dispersive X-ray microanalyzer (EDX) analysis verified the bioaccumulation of Al in testicular tissues due to its liberation from Al2O3 NPs, implying their penetration into the blood-testis barrier. Remarkably, toxicity with Al engendered disorders of antioxidant and stress biomarkers associated with substantial DNA damage and cell apoptosis. Furthermore, histopathological and ultrastructural analyses manifested significant aberrations in the testicular tissues from the group exposed to Al2O3 NPs, indicating the overproduction of reactive oxygen species (ROS). Molecular docking analysis emphasized the antioxidant capacity of some compounds derived from PAE. Thus, pretreatment with PAE counteracted the detrimental effects of Al in the testes, revealing antioxidant properties and thwarting DNA impairment and cell apoptosis. Moreover, histological and ultrastructural examinations revealed no anomalies in the testes. Overall, these findings substantiate the potential applications of PAE in preventing the testicular impairment of L. migratoria and the conceivable utilization of locusts for nanotoxicology studies.

Fatty acids for insect species remain constant: A case study of pink bollworm, Pectinophora gossypiella (Saunders)

Abstract Pink bollworm, Pectinophora gossypiella (Saunders) originates from South Asia and has spread across major cotton-growing regions. The pest is considered to be the most destructive and of economic concern across the globe. In India, the pest has developed resistance to dual Bt toxins and its concealed feeding nature makes the target sites almost inaccessible for the insecticide. In view of this issue, there is need to identify a suitable alternative for its management. In this context, semiochemicals serve as one of the best eco-friendly options. These chemical substances or mixtures broadcast messages for the purpose of communication. Semiochemicals may be released from eggs, faecal pellets, tarsal segments, scales, anal tufts and/or any insect components that reduce the intra/interspecific competition for shared resources such as food, mating, oviposition site etc. Accurate identification of the semiochemical compounds and their proportion in natural blends that arouse a strong behavioural response in insects, requires a thorough knowledge. Therefore in the present study, we tried to explore the chemicals present in eggs, faecal pellets and whole-body wash extracts of mated female. Seven compounds were identified from a methanolic extract of faecal-pellet samples, namely hexadecanoic acid, 9,12-octadecadienoic acid, 9-octadecenoic acid and their methyl esters along with methyl stearate. However, only four methyl-esterified forms were found in common in eggs and female body wash extract. This clearly shows that the compounds remain constant and conserved for the species but the role of these compounds needs to be demonstrated.

Effect of Dietary Administration of Green Macroalgae (Ulva intestinalis) on Mucosal and Systemic Immune Parameters, Antioxidant Defence, and Related Gene Expression in Zebrafish (Danio rerio).

This study investigated the effects of adding green macroalgae gutweed (Ulva intestinalis) powder to zebrafish (Danio rerio) feed at different levels on innate immune responses, antioxidant defence, and gene expression. A total of 600 zebrafish (0.3 ± 0.08 g) were randomly allocated to 12 aquariums in four treatments with three replicates (50 fish per aquarium). Zebrafish were fed with different levels of U. intestinalis powder 0, 0.25, 0.5, and 1% for eight weeks. Whole-body extract (WBE) immune parameters including total protein level, globulin level, and lysozyme activity were evaluated and revealed statistically significant increased in all U. intestinalis supplemented groups compared to the control (P < 0.05). However, mucus immune parameters (total protein, globulin, and lysozyme) were statistically different in only 1% gutweed supplemented groups from other groups. While glutathione peroxidase (GPx) and superoxide dismutase (SOD) increased with the addition of gutweed (P < 0.05), catalase (CAT) did not change (P > 0.05). The study results showed that dietary gutweed remarkably upregulated immune-related genes such as lysozyme (Lyz) and Interleukin 1 beta (IL-1β). Antioxidant-related genes (SOD and CAT) and growth-related genes, including growth hormone (GH) and insulin-like growth factor-I (IGF-1), were remarkably upregulated with gutweed treatment (P < 0.05). In conclusion, dietary U. intestinalis showed beneficial effects on immunity, and same effects were observed in case of antioxidant and growth related genes expression in zebrafish.

A DISCUSSION OF THE REFRACTORY PERIOD IN VENOM IMMUNOTHERAPY

<h3>Introduction</h3> Refractory periods are inconsistently observed phenomena that follow hypersensitivity reactions wherein a reaction is followed by a period of time during which additional reactions cannot be triggered. We discuss a case that challenges this theory. <h3>Case Description</h3> A 56-year-old male with Diabetes Mellitus II, Hypertension, and HIV presented with history of two prior episodes of fire ant stings leading to anaphylaxis. His baseline tryptase level was 6.1 ug/mL and sIgE to fire ant (Solenopsis invicta) was 42.3 kU/L. The patient completed the immunotherapy ultrarush induction protocol using 1:100wt/v Solenopsis invicta whole body extract (WBE) as the maintenance (1:1v/v) concentration. One hundred minutes after completion of the protocol, he developed throat tightness, nasal congestion, diffuse pruritus, and urticaria. Symptoms resolved after two injections of 0.5mL intramuscular epinephrine. One week later, he received 0.2 mL of 1:1 v/v and developed stridor, productive cough, and injected sclera 30 minutes after injection. Symptoms resolved with intramuscular epinephrine. The following week, he received another injection (decreased to 0.5 mL of 1:10 v/v) without incident. He continued weekly buildup to maintenance dose and subsequent monthly injections without additional reactions. <h3>Discussion</h3> In this case, completion of an ultrarush induction protocol and anaphylaxis failed to result in a refractory period of unresponsiveness, allowing for a second anaphylactic reaction to S. invicta WBE one week after desensitization should have been achieved. Additional research is needed to reliably identify patients experiencing a refractory period following an anaphylactic event. This would improve the accuracy of allergy testing and has the potential to make desensitization safer.

Dietary dragonhead effects on growth, immunity and antioxidant and related genes expression in zebrafish (Danio rerio)

The present study aimed to investigate the effects of the herbaceous plant, Dracocephalum kotschyi, on the immune response, antioxidant enzymes activity, growth performance, and related genes expression in zebrafish (Danio rerio). An in vivo trial was carried out by feeding zebrafish (initial weight of 0.47 ± 0.04 g) with different levels of powdered D. kotschyi: 0% (C-0%, control), 1% (Dk-1%), 2% (Dk-2%) and 3% (Dk-3%) for 10 weeks. The results show that total protein (TP) and total immunoglobulin (IG), were significantly increased in both skin mucus and whole body extract (WBE). Lysozyme (LYS) activity significantly increased in the WBE of zebrafish fed with D. kotschyi integrated diets compared to the control (P < 0.05). The superoxide dismutase (SOD) of WBE was significantly (P < 0.05) enhanced by dietary D. kotschyi. Additionally, this herb brought about a significant up-regulation in immune (LYS), pro-inflammatory (IL-1β) from intestine, and antioxidant (SOD and CAT) genes in liver, compared to the non-supplemented group (P < 0.05). Growth hormone (GH) and insulin growth factor (IGF) genes expression were upregulated significantly in zebrafish by the addition of D. kotschyi, although body weight did not change. The best results were obtained with the 3% inclusion of powdered D. kotschyi, except for LYS and IGF expressions that were best upregulated by 2% and 3% of D. kotschyi. Our results indicate that powdered D. kotschyi (suggested dose of 3%) could potentially improve zebrafish's immune response and antioxidant defense.

Evidence of Pheromone Use in a Fulgorid, Spotted Lanternfly

The spotted lanternfly, Lycorma delicatula (Hemiptera: Fulgoridae) is a polyphagous, phloem-feeding invasive forest, agricultural, and nuisance pest that is rapidly spreading through the U.S. Little is known about how fulgorids locate each other to mate. To determine if conspecific semiochemicals such as pheromones occur, whole body extracts (WBE) of adult spotted lanternflies from different physiological states were tested for attraction in a dual-choice olfactometer. In olfactometer assays, prior to mating, males were oriented to WBE from males and females. During their mating period, males were attracted to WBE of females, but not to that of males. After mating and oviposition had taken place, males were not attracted to either male or female extracts. Conversely, females did not orient to any WBE from either sex during any physiological state. These behavioral responses by males but not females to WBE from conspecifics in different physiological states suggest the possible presence of an aggregation-sex pheromone in the spotted lanternfly.

Long-term adherence to imported fire ant subcutaneous immunotherapy

BackgroundImported fire ant (IFA) whole-body extract subcutaneous immunotherapy (IT) is a safe and effective treatment for IFA hypersensitivity, with a recommended length of treatment of 3 to 5 years. ObjectiveTo evaluate long-term IFA IT adherence in patients with IFA allergy living in an endemic area. MethodsDuring 2007 to 2014, patients with IFA-sting systemic reactions and a recommendation to start IFA IT were prospectively enrolled in this study. Subjects were contacted annually for interval IT adherence. Institutional review board approval was obtained. ResultsA total of 87 subjects, ages 2 to 64 years, with a recommendation to initiate IFA IT, were enrolled. Subjects were predominantly adult (76%) and female (55%), and 30% had asthma. Of these patients, 77 (89%) initiated treatment within 1 year of recommendation; 18 (23%) adhered to a 3-year course; and 10 (13%) adhered to a 5-year course. At 3 years, there were no significant differences in adherence between male and female subjects (28% vs 19%, P = .33), children and adults (25% vs 22%, P = .79), or those with or without asthma (30% vs 20%, P = .31). Adherence in subjects with mild initial reactions was lower than in subjects with moderate-to-severe reactions (0% vs 25%, P = .05) at 3 years only. Conventional buildup and concurrent flying Hymenoptera venom immunotherapy were predictive of adherence. Reasons for discontinuation were relocation to a nonendemic area (29%) and inconvenience (27%). ConclusionThis study showed poor long-term adherence to IFA IT at 3 and 5 years. Initial sting severity, buildup protocol, and concurrent flying Hymenoptera venom immunotherapy were predictors for long-term IT adherence.

Can dietary Dictyota dichotoma powder affect performance, serum, and mucus immune parameters, and antioxidant defense in Zebrafish (Danio rerio)?

The present study was performed to study possible effects of Dictyota dichotoma which is a brown macroalgae on whole body extract (WBE) and skin mucus immune parameters, antioxidant enzyme activities as well as expression of growth, immune, and antioxidant related genes in zebrafish (Danio rerio). Zebrafish with an average weight of 0.3 ± 0.08 g were supplied and stocked in 12 aquariums. They were fed with different levels (0 %, 0.25 %, 0.5 %, and 1 %) of D. dichotoma powder for eight weeks. At the end of the trial, results revealed skin mucus immune parameters in fish treated with 1 % D. dichotoma were remarkably higher than control (P < 0.05). Similar results were obtained following evaluation of WBE total Ig and lysozyme activity (P < 0.05). Also, the activity of Superoxide dismutase (SOD) and glutathione S transferase (GST) were significantly increased (P < 0.05) when fish fed with 0.5 % and 1 % D. dichotoma supplemented diets. However, no significant alteration was noticed in the case of CAT (P > 0.05). The gene expression study revealed significant up-regulation of immune-related genes (LYZ and IL-1β) in fish fed D. dichotoma supplemented groups compared to the control group (P < 0.05). Regarding growth-related genes, D. dichotoma significantly increased GH and IGF1 expression in a dose-dependent manner (P < 0.05). Evaluation of SOD and CAT genes expression showed significant differences between the control group and treatments (P < 0.05). The highest increase was observed when zebrafish was fed 1 % macroalgae. In conclusion, the present findings suggested that adding 0.5–1 % of D. dichotoma powder to the zebrafish diet can positively affect fish antioxidant defense and immune system.

Efficacy of Utilization of All-Plant-Based and Commercial Low-Fishmeal Feeds in Two Divergently Selected Strains of Rainbow Trout (Oncorhynchus mykiss): Focus on Growth Performance, Whole-Body Proximate Composition, and Intestinal Microbiome.

The present study aimed to investigate the growth performance, whole-body proximate composition, and intestinal microbiome of rainbow trout strains when selected and non-selected for weight gain on all-plant protein diets. A 2x2 factorial design was applied, where a selected (United States) and a non-selected (ITA) rainbow trout strain were fed using either an all-plant protein (PP) or a commercial low-FM diet (C). Diets were fed to five replicates of 20 (PP) or 25 (C) fish for 105 days. At the end of the trial, growth parameters were assessed, and whole fish (15 pools of three fish/diet) and gut samples (six fish/diet) were collected for whole-body proximate composition and gut microbiome analyses, respectively. Independent of the administered diet, the United States strain showed higher survival, final body weight, weight gain, and specific growth rate when compared to the ITA fish (p < 0.001). Furthermore, decreased whole-body ether extract content was identified in the PP-fed United States rainbow trout when compared to the ITA strain fed the same diet (p < 0.001). Gut microbiome analysis revealed the Cetobacterium probiotic-like genus as clearly associated with the United States rainbow trout, along with the up-regulation of the pathway involved in starch and sucrose metabolism. In summary, the overall improvement in growth performance and, to a lesser extent, whole-body proximate composition observed in the selected rainbow trout strain was accompanied by specific, positive modulation of the intestinal microbiome.

Revisiting the trail pheromone components of the red imported fire ant, Solenopsis invicta Buren.

Ants use species-specific trail pheromones to coordinate their sophisticated foraging behavior. During the past decades, many trail pheromone components with various structures have been identified in ants, including the red imported fire ant, Solenopsis invicta, a notorious invasive species worldwide. Four compounds, Z,E- (ZEF) and E,E-α-farnesene (EEF), Z,E- (ZEHF) and E,E-α-homofarnesene (EEHF), have been reported as components of S. invicta trail pheromone. However, another study reported an analog of α-farnesene, Z,Z,Z-allofarnesene, as a key trail pheromone component. These contrasting results caused some uncertainty about the trail pheromone composition in S. invicta. In this study, we synthesized ZEF and EEF, ZEHF and EEHF, and reanalyzed the chemicals in the Dufour gland extract and in the trail pheromone fraction of S. invicta worker body extract. The reported isomers of farnesene and homofarnesene were detected and showed trail-following activity, with ZEF as the major compound, while no allofarnesene was found, neither in the Dufour gland extract nor in the whole-body extract. Our results confirm ZEF and EEF, ZEHF and EEHF as trail pheromone components of S. invicta.

Mosquitoes: Important Sources of Allergens in the Tropics.

There are more than 3,000 mosquito species. Aedes aegypti, Ae. communis, and C. quinquefasciatus are, among others, three of the most important mosquito allergen sources in the tropics, western, and industrialized countries. Several individuals are sensitized to mosquito allergens, but the epidemiological data indicates that the frequency of sensitization markedly differs depending on the geographical region. Additionally, the geographical localization of mosquito species has been affected by global warming and some mosquito species have invaded areas where they were not previously found, at the same time as other species have been displaced. This phenomenon has repercussions in the pathogenesis and the accuracy of the diagnosis of mosquito allergy. Allergic individuals are sensitized to mosquito allergens from two origins: saliva and body allergens. Exposure to saliva allergens occurs during mosquito bite and induces cutaneous allergic reactions. Experimental and clinical data suggest that body allergens mediate different manifestations of allergic reactions such as asthma and rhinitis. The most studied mosquito species is Ae. aegypti, from which four and five allergens of the saliva and body, respectively, have been reported. Many characterized allergens are homologs to arthropod-derived allergens, which cause strong cross-reactivity at the humoral and cellular level. The generalized use of whole body Ae. communis or C. quinquefasciatus extracts complicates the diagnosis of mosquito allergy because they have low concentration of saliva allergens and may result in poor diagnosis of the affected population when other species are the primary sensitizer. This review article discusses the current knowledge about mosquito allergy, allergens, cross-reactivity, and proposals of component resolved approaches based on mixtures of purified recombinant allergens to replace saliva-based or whole-body extracts, in order to perform an accurate diagnosis of allergy induced by mosquito allergen exposure.

The Validity of Brine Shrimp (Artemia Sp.) Toxicity Assays to Assess the Ecological Function of Marine Natural Products.

Many organisms employ toxic compounds for protection against predators. To understand the effectiveness of such compounds, chemoecological studies often use brine shrimp (Artemia spp.) as a model organism instead of more ecologically relevant species. This is mostly because brine shrimp assays are simple and quick, but also due to the ethical implications associated with inducing harm to vertebrate predators in toxicity assays. In this study, we examined whether brine shrimp assays produce similar results to ichthyological toxicity assays with the aim of validating the use of brine shrimp as a preliminary screening tool. We extracted compounds from eight nudibranch molluscs including six species that we consider to signal their chemical defenses via warning coloration to visually hunting vertebrate predators. We tested the relative toxicity of these compounds against brine shrimp and a vertebrate potential predator, the blue-green damselfish (Chromis viridis). We found that extracts toxic to brine shrimp were also toxic to damselfish; however, extracts non-toxic to brine shrimp may still be toxic to damselfish. We also produced and tested mantle vs whole-body extracts for some nudibranch species, which exhibited similar toxicities in both assays except for the whole-body extract of Goniobranchus splendidus which was harmless to shrimp but toxic to fish, while the mantle extract was toxic to both. Overall, we argue that the brine shrimp assay can reasonably indicate the potential toxicity of a compound to fish, but additional experiments with more ecologically relevant predators are required if a no dose-response is observed against brine shrimp.