Spider Venom Research Articles

<i>Loxosceles rufescens</i>: single-institutional epidemiology, diagnosis and treatment

Loxosceles rufescens, also known as “violin spider” due to its characteristic appearance, is a medium-sized spider species that can potentially pose a threat to humans. For this study, patients who presented to our hospital’s Poison Control Center between January 1, 2022, and December 31, 2022, and met the following inclusion criteria were included: Suspicion of a violin spider bite, as evaluated by our center. Our protocol involves an initial local treatment, which includes local washing with copious water and disinfection, along with the application of chlorotetracycline hydrochloride. Systemic therapy utilizes Amoxicillin and Clavulanic Acid as the first-line medication. The primary endpoints of this study are the timing and effectiveness of the treatment for cutaneous lesions. Demographic and anamnestic information regarding age, gender, and timelines was summarized using descriptive methods. Our study’s results indicate that erythema and pain are the most frequent symptoms. Loxoscelism is highly concentrated in the Western hemisphere and is considered the only proven arachnological cause of dermo-necrosis. In recent years, there has been an increase in diagnoses.

Acute generalized exanthematous pustulosis secondary to spider bites: Clinico-dermoscopic findings and review of literature

Acute generalized exanthematous pustulosis (AGEP) or toxic pustuloderma is a febrile adverse cutaneous reaction, characterized by small non-follicular sterile pustules. AGEP can occur in any age group and is found to be more common in women. A large proportion (>90%) of cases are triggered by medications, particularly macrolides and aminopenicillins. The occurrence of AGEP following spider bite has been rarely documented in the literature.We report two cases who presented to us with AGEP following spider bite along with dermoscopic findings and also present a brief review of literature on the same.

Spider venom neurotoxin based bioinsecticides: A novel bioactive for the control of the Asian citrus psyllid Diaphorina citri (Hemiptera)

The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), is a key vector of the phloem-limited bacteria Candidatus Liberibacter asiaticus (CLas) associated with huanglongbing (HLB), the most serious and currently incurable disease of citrus worldwide. Here we report the first investigation into the potential use of a spider venom-derived recombinant neurotoxin, ω/κ-HxTx-Hv1h (hereafter HxTx-Hv1h) when delivered alone or when fused to snowdrop lectin (Galanthus nivalis agglutinin; GNA) to control D. citri. Proteins, including GNA alone, were purified from fermented transformed yeast Pichia pastoris cultures. Recombinant HxTx-Hv1h, HxTx-Hv1h/GNA and GNA were all orally toxic to D. citri, with Day 5 median lethal concentrations (LC50) derived from dose-response artificial diet assays of 27, 20 and 52 μM, respectively. Western analysis of whole insect protein extracts confirmed that psyllid mortality was attributable to protein ingestion and that the fusion protein was stable to cleavage by D. citri proteases. When applied topically (either via droplet or spray) HxTx-Hv1h/GNA was the most effective of the proteins causing >70 % mortality 5 days post treatment, some 2 to 3-fold higher levels of mortality as compared to the toxin alone. By contrast, no significant mortality or phenotypic effects were observed for bumble bees (Bombus terrestris L.) fed on the recombinant proteins in acute toxicity assays. This suggests that HxTx-Hv1h/GNA has potential as a novel bioinsecticide for the management of D. citri offering both enhanced target specificity as compared to chemical pesticides and compatibility with integrated pest management (IPM) strategies.

Brown spiders (Loxosceles) are taking hold in Pernambuco, Brazil: a case series, 2018-2022.

To describe accidents involving brown spider (genus Loxosceles) bites notified by the Pernambuco Poison Information and Care Center (CIATox-PE), Brazil, from January 2018 to December 2022. This was a case series study of brown spider bites notified by the CIATox-PE. The study included 22 cases with median age of 35 years, the majority being female (13); the cases occurred in rural and urban areas (12 versus 10), at night (10); Petrolina was the municipality with the highest number of notifications (6); spider bites occurred mainly in the lower (11) and upper (9) limbs, almost exclusively inside households (21); specific serum therapy was not indicated for 8 cases because the time for its effectiveness had already elapsed. Loxoscelism cases occurred more frequently in females, in both rural and urban areas and mainly at home, with delays in seeking medical care. The 22 cases described represent an alert for the presence of a venomous species not reported in previous studies in Pernambuco. The severity of cases may be associated with delays in seeking medical care, especially due to the population's lack of information. Identify the presence of brown spiders in households in the region and the potential severity of poisonings. Alert health professionals to recognize the clinical picture with a view to appropriate early treatment. Develop research on poisoning by venomous animals and educational actions alerting the population to prevent these accidents and updating health professionals on care.

Electrophysiological evaluation of the effect of peptide toxins on voltage-gated ion channels: a scoping review on theoretical and methodological aspects with focus on the Central and South American experience.

The effect of peptide toxins on voltage-gated ion channels can be reliably assessed using electrophysiological assays, such as the patch-clamp technique. However, much of the toxinological research done in Central and South America aims at purifying and characterizing biochemical properties of the toxins of vegetal or animal origin, lacking electrophysiological approaches. This may happen due to technical and infrastructure limitations or because researchers are unfamiliar with the techniques and cellular models that can be used to gain information about the effect of a molecule on ion channels. Given the potential interest of many research groups in the highly biodiverse region of Central and South America, we reviewed the most relevant conceptual and methodological developments required to implement the evaluation of the effect of peptide toxins on mammalian voltage-gated ion channels using patch-clamp. For that, we searched MEDLINE/PubMed and SciELO databases with different combinations of these descriptors: "electrophysiology", "patch-clamp techniques", "Ca2+ channels", "K+ channels", "cnidarian venoms", "cone snail venoms", "scorpion venoms", "spider venoms", "snake venoms", "cardiac myocytes", "dorsal root ganglia", and summarized the literature as a scoping review. First, we present the basics and recent advances in mammalian voltage-gated ion channel's structure and function and update the most important animal sources of channel-modulating toxins (e.g. cnidarian and cone snails, scorpions, spiders, and snakes), highlighting the properties of toxins electrophysiologically characterized in Central and South America. Finally, we describe the local experience in implementing the patch-clamp technique using two models of excitable cells, as well as the participation in characterizing new modulators of ion channels derived from the venom of a local spider, a toxins' source less studied with electrophysiological techniques. Fostering the implementation of electrophysiological methods in more laboratories in the region will strengthen our capabilities in many fields, such as toxinology, toxicology, pharmacology, natural products, biophysics, biomedicine, and bioengineering.

Production of recombinant DNA fragmentation factor 40 in fusion to an antimicrobial peptide from spider venom and evaluation of its cytotoxic effects.

DNA fragmentation factor 40 (DFF40) as an apoptotic molecule can represent a novel approach to cancer treatment. Lycosin-I (LYC-I), a peptide derived from spider venom, was considered for the targeted delivery of DFF40 to cancer cells. This study attempted to produce soluble DFF40-LYC-I and evaluate its selective lethal effects on HeLa cells. pTWINl vector was used to produce LYC-I and DFF40-LYC-I in E. coli BL21 (DE3) fused to inteins 1 and 2. IPTG concentration and incubation temperature were optimized to achieve the highest level of soluble product. To remove inteins 1 and 2 from the recombinant peptide or protein, pH shift and dithiothreitol were used for a 24-h incubation period at room temperature, respectively. MTT assay was performed to assess the biological effects of these bio-molecules on HeLa and HUVEC cell lines. LYC-I and DFF40-LYC-I were detected in SDS-PAGE with bands of approximately 57 and 97 kDa, respectively. Furthermore, the 3 and 43 kDa bands showed the purified molecules. The IC50 value of DFF40-LYC-I and DFF40 was determined as 6.6 and 17.03 μg/mL for HeLa, respectively. LYC-I had no cytotoxic effects on both cell lines, even at high concentrations. A new fusion protein with targeted cancer treatment potential was produced for the first time by LYC-I with a safe profile on normal cells. This fusion protein exhibited higher cytotoxic effects in cancer cells compared to normal cells. However, additional investigations are required to determine the apoptosis induction and evaluate selective toxicity against other cancer and normal cell lines.

Identification of Peptides in Spider Venom Using Mass Spectrometry.

Spider venoms are composed of hundreds of proteins and peptides. Several of these venom toxins are cysteine-rich peptides in the mass range of 3-9kDa. Small peptides (<3kDa) can be fully characterized by mass spectrometry analysis, while proteins are generally identified by the bottom-up approach in which proteins are first digested with trypsin to generate shorter peptides for MS/MS characterization. In general, it is sufficient for protein identification to sequence two or more peptides, but for venom peptidomics it is desirable to completely elucidate peptide sequences and the number of disulfide bonds in the molecules. In this chapter, we describe a methodology to completely sequence and determine the number of disulfide bonds of spider venom peptides in the mass range of 3-9kDa by multiple enzyme digestion, mass spectrometry of native and digested peptides, de novo analysis, and sequence overlap alignment.

Protective effects of mesenchymal stromal cell-derived secretome on dermonecrosis induced in rabbits by Loxosceles intermedia spider venom.

Loxoscelism refers to a set of clinical manifestations caused by the bite of spiders from the Loxosceles genus. The classic clinical symptoms are characterized by an intense inflammatory reaction at the bite site followed by local necrosis and can be classified as cutaneous loxoscelism. This cutaneous form presents difficult healing, and the proposed treatments are not specific or effective. This study aimed to evaluate the protective effect of mesenchymal stromal cells-derived secretome on dermonecrosis induced by Loxosceles intermedia spider venom in rabbits. Sixteen rabbits were distributed into four groups (n = 4). Except for group 1 (G1), which received only PBS, the other three groups (G2, G3, and G4) were initially challenged with 10 μg of L. intermedia venom, diluted in 100 μL of NaCl 0.9%, by intradermic injection in the interscapular region. Thirty minutes after the challenge all groups were treated with secretome, except for group 2. Group 1 (G1-control group) received intradermal injection (ID) of 60 μg of secretome in 0.15 M PBS; Group 2 (G2) received 0.9% NaCl via ID; Group 3 (G3) received 60 μg of secretome, via ID and Group 4 (G4), received 60 μg of secretome by intravenous route. Rabbits were evaluated daily and after 15 days were euthanized, necropsied and skin samples around the necrotic lesions were collected for histological analysis. Rabbits of G1 did not present edema, erythema, hemorrhagic halo, or necrosis. In animals from G2, G3, and G4, edema appeared after 6h. However, minor edema was observed in the animals of G2 and G3. Hemorrhagic halo was observed in animals, six hours and three days after, on G2, G3, and G4. Macroscopically, in G4, only one animal out of four had a lesion that evolved into a dermonecrotic wound. No changes were observed in the skin of the animals of G1, by microscopic evaluation. All animals challenged with L. intermedia venom showed similar alterations, such as necrosis and heterophilic infiltration. However, animals from G4 showed fibroblast activation, early development of connective tissue, neovascularization, and tissue re-epithelialization, indicating a more prominent healing process. These results suggest that secretome from mesenchymal stromal cells cultured in a xeno-free and human component-free culture media can be promising to treat dermonecrosis caused after Loxosceles spiders bite envenoming.

Clinical characteristics, management, outcome, and cost of stings and bites in patients admitted to a tertiary care teaching hospital.

The objective of this study was to identify the clinical epidemiology and medical cost of stings and bites at a tertiary care hospital in South India. The medical records of hospitalized patients in the tertiary care unit between 2016 and 2020 with the history of either being stung or bitten by insects were reviewed retrospectively. The patient's demographic details, clinical symptoms, treatment chart, expenditure details, and outcomes were collected in pre-structured case report forms. The data were analyzed using SPSS Version 20.0. A total of 66 patients were enrolled, with a mean age of 45.86±23.37 years. The majority of the incidence was due to bee stings (61%). Anaphylaxis was reported in 38% of the cases, followed by acute kidney injury (10.6%). The cost of hospitalization was found to be higher for spider bites at 896.73±1414.95 USD, followed by wasp stings at 989.81±1185.57 USD. In patients with complications, the average cost of stings and bites was 438.81±685.81 USD. Most of the patients received antibiotics (75.8%), followed by steroids (62.1%). Stings and bite injuries may appear harmless initially, but they can cause severe complications in unidentified cases and for those who do not seek urgent medical attention. Antibiotics and corticosteroids can help in the management of envenomation.

Kiosk 6Q-TA-09 - Uncommon Cardiac Complications Following Loxosceles Rufescens Spider Bite: A Case Report with Diagnostic Insights

Kiosk 6Q-TA-09 - Uncommon Cardiac Complications Following Loxosceles Rufescens Spider Bite: A Case Report with Diagnostic Insights

Spider-Venom Peptides: Structure, Bioactivity, Strategy, and Research Applications.

Spiders (Araneae), having thrived for over 300 million years, exhibit remarkable diversity, with 47,000 described species and an estimated 150,000 species in existence. Evolving with intricate venom, spiders are nature's skilled predators. While only a small fraction of spiders pose a threat to humans, their venoms contain complex compounds, holding promise as drug leads. Spider venoms primarily serve to immobilize prey, achieved through neurotoxins targeting ion channels. Peptides constitute a major part of these venoms, displaying diverse pharmacological activities, and making them appealing for drug development. Moreover, spider-venom peptides have emerged as valuable tools for exploring human disease mechanisms. This review focuses on the roles of spider-venom peptides in spider survival strategies and their dual significance as pharmaceutical research tools. By integrating recent discoveries, it provides a comprehensive overview of these peptides, their targets, bioactivities, and their relevance in spider survival and medical research.

Inhibition of nicotinic acetylcholine receptors by oligoarginine peptides and polyamine-related compounds.

Oligoarginine peptides, known mostly for their cell-penetrating properties, are also inhibitors of the nicotinic acetylcholine receptors (nAChRs). Since octa-arginine (R8) inhibits α9α10 nAChR and suppresses neuropathic pain, we checked if other polycationic compounds containing amino and/or guanidino groups could be effective and tested the activity of the disulfide-fixed "cyclo"R8, a series of biogenic polyamines (putrescine, spermidine, and spermine), C-methylated spermine analogs, agmatine and its analogs, as well as acylpolyamine argiotoxin-636 from spider venom. Their inhibitory potency on muscle-type, α7 and α9α10 nAChRs was determined using radioligand analysis, electrophysiology, and calcium imaging. "Cyclo"R8 showed similar activity to that of R8 against α9α10 nAChR (IC50 ≈ 60nM). Biogenic polyamines as well as agmatine and its analogs displayed low activity on muscle-type Torpedo californica, as well as α7 and α9α10 nAChRs, which increased with chain length, the most active being spermine and its C-methylated derivatives having IC50 of about 30μM against muscle-type T. californica nAChR. Argiotoxin-636, which contains a polyamine backbone and terminal guanidino group, also weakly inhibited T. californica nAChR (IC50 ≈ 15μM), but it revealed high potency against rat α9α10 nAChR (IC50 ≈ 200nM). We conclude that oligoarginines and similar polycationic compounds effectively inhibiting α9α10 nAChR may serve as a basis for the development of analgesics to reduce neuropathic pain.

On the Tarantula: 17th-century Latin University Scholars on Spider Bites, Madness and the Role of Music

On the Tarantula: 17th-century Latin University Scholars on Spider Bites, Madness and the Role of Music

The Identification of a Novel Spider Toxin Peptide, Lycotoxin-Pa2a, with Antibacterial and Anti-Inflammatory Activities.

With the increasing challenge of controlling infectious diseases due to the emergence of antibiotic-resistant strains, the importance of discovering new antimicrobial agents is rapidly increasing. Animal venoms contain a variety of functional peptides, making them a promising platform for pharmaceutical development. In this study, a novel toxin peptide with antibacterial and anti-inflammatory activities was discovered from the spider venom gland transcriptome by implementing computational approaches. Lycotoxin-Pa2a (Lytx-Pa2a) showed homology to known-spider toxin, where functional prediction indicated the potential of both antibacterial and anti-inflammatory peptides without hemolytic activity. The colony-forming assay and minimum inhibitory concentration test showed that Lytx-Pa2a exhibited comparable or stronger antibacterial activity against pathogenic strains than melittin. Following mechanistic studies revealed that Lytx-Pa2a disrupts both cytoplasmic and outer membranes of bacteria while simultaneously inducing the accumulation of reactive oxygen species. The peptide exerted no significant toxicity when treated to human primary cells, murine macrophages, and bovine red blood cells. Moreover, Lytx-Pa2a alleviated lipopolysaccharide-induced inflammation in mouse macrophages by suppressing the expression of inflammatory mediators. These findings not only suggested that Lytx-Pa2a with dual activity can be utilized as a new antimicrobial agent for infectious diseases but also demonstrated the implementation of in silico methods for discovering a novel functional peptide, which may enhance the future utilization of biological resources.

Acute generalized exanthematous pustulosis: Analysis of cases managed in a Tunisian tertiary hospital

Acute generalized exanthematous pustulosis (AGEP) is a severe and life-threatening cutaneous adverse reaction. Drug-induced AGEP is mainly related to antibiotics. More recently, AGEP following spider bites has been increasingly described. Treatment includes withdrawal of the offending drug and supportive care. In Tunisia, data concerning severe cutaneous adverse reactions (SCARs) in general and especially AGEP is lacking. Herein, we conducted a retrospective study to investigate the epidemiological, clinical characteristics and etiologies of AGEP referred to the Dermatology department. Our study included 32 cases of AGEP. AGEP cases occurred in overall 8.9% of all SCARs referred to the department during the same period study. The majority were females (24 women and 7 men). The median age of the patients was 33 years. A history of psoriasis was reported in 16.1% of patients. All patients presented with an extensive erythematous rash with pinhead pustules. Neutrophil hyperleukocytosis (greater than 7000/mm3) was noted in 17 patients (63% of cases). It was associated with hypereosinophilia exceeding 500 elements/mm3 in 8 cases (29.6%). Drug-induced AGEP was reported in 53% of cases. Antibiotics were implicated in the majority of cases. Delay in onset ranged from 15hours to 7 days, with an average of 2.8 days. A non-drug-induced etiology was considered if the pharmacological investigation was negative, or if a clear non-drug trigger was found. It was retained in ten cases (48.4% of all observations). Spider bites were revealed in 8 cases. AGEP represents a severe, usually drug-related skin reaction. It is classified as a type IVd reaction mediating T cell-related sterile neutrophilic inflammatory response. It typically occurs within 24-48h of ingestion of the offending drug. Antibiotics are the most common drug family to cause AGEP. Spider bites were involved in 25.8% of cases in our study, as important as antibiotic-induced AGEP. Analysis of the particularities of AGEP according to etiology, whether drug-induced or not, revealed the presence of an initial escarotic lesion (P=0.01) and the finding of blood hypereosinophilia (P=0.014) in the non-drug AGEP group were the distinguishing features. Blood hyperesoniophilia, more frequent in the non-drug AGEP group, suggests a pathophysiology probably different from that of the drug AGEP group. Clinicians should be aware of both etiologies. Our study focuses on the importance of AGEP associated with spider bite as a potential triggering factor in Tunisia.

Recombinant Production of TP4-LYC1, A New Chimeric Peptide with Targeted Cytotoxicity to HeLa Cells.

Tilapia Piscidin 4 (TP4) showed potential anti-tumor effects against various cancer cells. Lycosine-1 (LYC1), is another Antimicrobial Peptides (AMP) from spider venom with targeted penetration to cancer cells without any adverse effects on normal cells. The aim of this study was to produce a soluble recombinant fusion peptide in order to diminish the cytotoxicity of TP4 against normal cells. In order to express of TP4-LYC-1, TP4, and LYC1 in fusion to the inteins1/2 of pTWIN-1 vector, induction condition was optimized to earn soluble peptides. Auto-cleavage induction of inteins1/2 was performed based on IMPACT® manual and their effect on cell viability of HeLa and HUVEC cells was surveyed by MTT assay. The best condition for accessing the most soluble peptide in fusion to the inteins was approximately similar for all three peptides (0.1 mM of IPTG, at 22°C). After the induction of self-cleavage of inteins, a band in 3, 3, and 6 kDa was observed on tricine-SDS-PAGE. The IC50 values of TP4-LYC1 and TP4 against HeLa cells were calculated as 0.83, and 2.75 μM, respectively. In the present study, a novel chimeric peptide, TP4-LYC1, was successfully produced. This fusion protein can act as a safe bio-molecule with potent cytotoxic effects against cancer cells, but the penetration ability and determination of cell death mechanism must be performed in order to have more precise view on the apoptosis induction of this recombinant peptide.

In Silico-Based Design of a Hybrid Peptide with Antimicrobial Activity against Multidrug-Resistant Pseudomonas aeruginosa Using a Spider Toxin Peptide.

The escalating prevalence of antibiotic-resistant bacteria poses an immediate and grave threat to public health. Antimicrobial peptides (AMPs) have gained significant attention as a promising alternative to conventional antibiotics. Animal venom comprises a diverse array of bioactive compounds, which can be a rich source for identifying new functional peptides. In this study, we identified a toxin peptide, Lycotoxin-Pa1a (Lytx-Pa1a), from the transcriptome of the Pardosa astrigera spider venom gland. To enhance its functional properties, we employed an in silico approach to design a novel hybrid peptide, KFH-Pa1a, by predicting antibacterial and cytotoxic functionalities and incorporating the amino-terminal Cu(II)- and Ni(II) (ATCUN)-binding motif. KFH-Pa1a demonstrated markedly superior antimicrobial efficacy against pathogens, including multidrug-resistant (MDR) Pseudomonas aeruginosa, compared to Lytx-Pa1a. Notably, KFH-Pa1a exerted several distinct mechanisms, including the disruption of the bacterial cytoplasmic membrane, the generation of intracellular ROS, and the cleavage and inhibition of bacterial DNA. Additionally, the hybrid peptide showed synergistic activity when combined with conventional antibiotics. Our research not only identified a novel toxin peptide from spider venom but demonstrated in silico-based design of hybrid AMP with strong antimicrobial activity that can contribute to combating MDR pathogens, broadening the utilization of biological resources by incorporating computational approaches.

Venom-gland transcriptomics and venom proteomics of the Tibellus oblongus spider

The Tibellus oblongus spider is an active hunter that does not spin webs and remains highly underinvestigated in terms of the venom composition. Here, we describe venom glands transcriptome and venom proteome analysis for unveiling the polypeptide composition of Tibellus oblongus spider venom. The resulting EST database includes 1733 records, including 1263 nucleotide sequences with ORFs, of these 942 have been identified as toxin-coding. The database of peptide sequences was built based on of the transcriptomics results. It contains 217 new toxins, 212 of them were detected in the T. oblongus venom by the proteomics.

Response to "Acute Localized Exanthematous Pustulosis Induced by a Spider Bite".

Response to "Acute Localized Exanthematous Pustulosis Induced by a Spider Bite".

Unveiling hidden toxin diversity: Discovery of novel venom components through manual curation of highly expressed sequences annotated as “no hits” in Phoneutria nigriventer spider venom gland transcriptome

Spider venoms have evolved over thousands of years, optimizing feeding and defense mechanisms. Venom components show pharmacological and biotechnological potential, rising interest in their study. However, the isolation of spider toxins for experimental evaluation poses significant challenges. To address this, transcriptomic analysis combined with computational tools has emerged as an appealing approach to characterizing spider venoms. However, many sequences remain unidentified after automatic annotation. In this study, we manually curated a subset of previously unannotated sequences from the Phoneutria nigriventer transcriptome and identified new putative venom components. Our manual analysis revealed 29 % of the analyzed sequences were potential venom components, 29 % hypothetical/uncharacterized proteins, and 17 % cellular function proteins. Only 25 % of the originally unannotated dataset remained without any identification. Most reclassified components were cysteine-rich peptides, including 23 novel putative toxins. We also found glycine-rich peptides (GRP), corroborating the previous description of GRPs in Phoneutria pertyi venom glands. Furthermore, to emphasize the recurrence of the lack of annotation in spider venom glands transcripts, we provide a survey of the percentage of unidentified sequences in several published spider venom transcriptomics studies. In conclusion, our study highlights the importance of manual curation in uncovering novel venom components and underscores the need for improved annotation strategies to fully exploit the medical and biotechnological potential of spider venoms.