Amount Of Venom Research Articles

Paradoxical Exception to Island Tameness: Increased Defensiveness in an Insular Population of Rattlesnakes.

Island tameness results largely from a lack of natural predators. Because some insular rattlesnake populations lack functional rattles, presumably the consequence of relaxed selection from reduced predation, we hypothesized that the Santa Catalina Island, California, USA, population of the southern Pacific rattlesnake (Crotalus helleri, which possesses a functional rattle), would exhibit a decrement in defensive behavior relative to their mainland counterparts. Contrary to our prediction, rattlesnakes from the island not only lacked tameness compared to mainland snakes, but instead exhibited measurably greater levels of defensiveness. Island snakes attempted to bite 4.7 times more frequently as we endeavored to secure them by hand, and required 2.1-fold more time to be pinned and captured. When induced to bite a beaker after being grasped, the island snakes also delivered 2.1-fold greater quantities of venom when controlling for body size. The additional venom resulted from 2.1-fold larger pulses of venom ejected from the fangs. We found no effects of duration in captivity (2-36 months), which suggests an absence of long-term habituation of antipredator behaviors. Breeding bird surveys and Christmas bird counts indicated reduced population densities of avian predators on Catalina compared to the mainland. However, historical estimates confirmed that populations of foxes and introduced mammalian predators (cats and pigs) and antagonists (herbivorous ungulates) substantially exceeded those on the mainland in recent centuries, and therefore best explain the paradoxically exaggerated defensive behaviors exhibited by Catalina's rattlesnakes. These findings augment our understanding of anthropogenic effects on the behaviors of island animals and underscore how these effects can negatively affect human safety.

Quantifying venom production: A study on Micrurus snakes in Mexico

Our study quantifies venom production in nine Mexican coral snake species (Micrurus), encompassing 76 specimens and 253 extractions. Noteworthy variations were observed, with M. diastema and M. laticollaris displaying diverse yields, ranging from 0.3 mg to 59 mg. For animals for which we have length data, there is a relationship between size and venom quantity. Twenty-eight percent of the observed variability in venom production can be explained by snake size, suggesting that other factors influence the amount of obtained venom. These findings are pivotal for predicting venom effects and guiding antivenom interventions. Our data offer insights into Micrurus venom yields, laying the groundwork for future research and aiding in medical response strategies. This study advances understanding coral snake venom production, facilitating informed medical responses to coral snake bites.

Heterologous Expression and Immunogenic Potential of the Most Abundant Phospholipase A2 from Coral Snake Micrurus dumerilii to Develop Antivenoms.

Micrurus dumerilii is a coral snake of clinic interest in Colombia. Its venom is mainly composed of phospholipases A2 being MdumPLA2 the most abundant protein. Nevertheless, Micrurus species produce a low quantity of venom, which makes it difficult to produce anticoral antivenoms. Therefore, in this work, we present the recombinant expression of MdumPLA2 to evaluate its biological activities and its immunogenic potential to produce antivenoms. For this, a genetic construct rMdumPLA2 was cloned into the pET28a vector and expressed heterologously in bacteria. His-rMdumPLA2 was extracted from inclusion bodies, refolded in vitro, and isolated using affinity and RP-HPLC chromatography. His-rMdumPLA2 was shown to have phospholipase A2 activity, a weak anticoagulant effect, and induced myonecrosis and edema. The anti-His-rMdumPLA2 antibodies produced in rabbits recognized native PLA2, the complete venom of M. dumerilii, and a phospholipase from another species of the Micrurus genus. Antibodies neutralized 100% of the in vitro phospholipase activity of the recombinant toxin and a moderate percentage of the myotoxic activity of M. dumerilii venom in mice. These results indicate that His-rMdumPLA2 could be used as an immunogen to improve anticoral antivenoms development. This work is the first report of an M. dumerilii functional recombinant PLA2.

Muscle spasms – A common symptom following theraphosid spider bites?

Despite the popularity of theraphosids, detailed reports on bite symptoms are still limited to few geographic regions and subfamilies. We therefore examined 363 published bite reports and noticed muscles cramps caused by theraphosids from nearly all continents and subfamilies. Symptoms are mostly locally restricted and mild, but 12.7% of victims experience pronounced cramps with highest incidence rates by Poecilotheriinae, Harpactirinae and Stromatopelminae subfamilies. We discuss how variations in venom quantity correlate with muscle cramp prevalence.

Scorpion envenomation: state of the art.

Scorpion envenomation is common in the tropical and subtropical regions. It poses a major public health problem with some patients having serious clinical manifestations and severe complications including death. Old World and New World scorpions are usually contrasted because of differences in venom composition, clinical presentation and severity, and, accordingly, different therapeutic approaches. The majority of scorpion stings are either dry or result in low amounts of injected venom, thus explaining why up to 95% of scorpion stings ensue only in local signs. For a clinical envenomation to occur, it has been suggested that the interaction between the quantity of venom introduced in the body of the prey and the distribution volume should ensue in a critical threshold of scorpion toxin plasma concentration. In this case, there is a massive release of neurohormonal mediators (mainly catecholamine), with systemic vasoconstrictor effects eliciting a sharp increase in systemic arterial pressure and LV-filling pressure and decreased cardiac output. This early phase of cardiac dysfunction, also called "vascular phase", is followed by a severe cardiomyopathy, a form of Takotsubo cardiomyopathy, involving both ventricles and reversible in days to weeks. The more comprehensive understanding of the disease pathophysiology has allowed for a well-codified symptomatic treatment, thus contributing to a substantial reduction in the death toll of scorpion envenomation over the past few decades. The standard intensive-care treatment (when available) overcomes envenomation's consequences such as acute pulmonary edema and cardiogenic shock. Even though it continues to inspire many evaluative studies, immunotherapy seems less attractive because of the major role held by mediators in the pathogenesis of envenomation, and unfavorable pharmacokinetic properties to existing sera compared to venom. Meta-analyses of controlled trials of immunotherapy in severe scorpion envenomation reached similar conclusions: there is an acceptable level of evidence in favor of the use of scorpion antivenom (Fab'2) against Centruroides sp. in USA/Mexico, while there is still a need for a higher level of evidence for immunotherapy in the Old World envenomation.

Role of venom quantity in the feeding behavior of Jaguajir rochae (Scorpiones: Buthidae)

Animal venom is composed of a complex mixture of protein-rich chemicals. Synthesis of animal venom incurs a high metabolic cost and is a prolonged process; consequently, animals use their venom cautiously and economically. Some studies have shown that venomous animals modulate the amount and/or type of venom used depending on certain factors, such as prey size or the intensity of predation threat. Here, we investigated how the quantity of venom that is available for use by the scorpion Jaguajir rochae interferes with its choice of prey. We used two types of prey of contrasting size (small 200–300-mg and large 600–700-mg cockroaches). The results showed that the amount of venom influences the feeding behavior of this species. Most scorpions without venom exhibited a low interest when large prey was present, but frequently attacked small prey. The scorpions also showed a distinct pattern in the time between venom extraction and the initiation of hunting behavior. In conclusion, J. rochae is able to perceive differences between small and large prey and make decisions regarding venom usage, supporting the “venom optimization hypothesis” (or “venom metering hypothesis”), by minimizing the venom use due to it being an energetically expensive resource.

Effect of Milking Method, Diet, and Temperature on Venom Production in Scorpions

In the present study, two common buthid scorpions, i.e., Androctonus finitimus (Pocock, 1897) (Scorpiones: Buthidae) and Hottentota tamulus (Fabricus, 1798) (Scorpiones: Buthidae), were maintained in the laboratory for venom recovery. The aim of study was to compare the quantity and quality of venom extracted from scorpions by manual and electrical method. We also recorded the effect of diet and temperature on venom production. Results of our study revealed that electrical method yielded good quality and higher quantity of venom as compared to manual method. The quantity of venom by two studied species differed statistically. We recorded the effect of food on venom production by providing different prey items to the scorpions and found that grasshopper nymphs and adults were the best diet for the scorpions to get maximum yield of venom as compared to other prey types (house crickets, house flies, and moths). Production of venom and activity of scorpions was found to be associated with temperature. During winter season, venom recovery was comparatively low as compared to the hottest part of year; when venom milking and activity of scorpions both were increased.

EFFECT OF SOME FACTORS ON HONEY BEE VENOM PRODUCTION FROM DIFFERENT STRAINS

These experiments were carried out at the apiary of honeybee research center of Faculty of Environmental Agricultural Sciences, Arish University, North Sinai, Egypt. To study some factors that affecting on the honey bee venom collection (bee race, season of the year and supplemental protein nutrition) on collected venom quantity .The results showed that the Italian hybrid gave the largest quantity of venom. Spring and summer are the best seasons for collecting the largest quantity of the bee venom. The pollen grain and dried Moringa leaves diets treatments gave the best results for bee venom production comparing with the other treatments (mixture of soybean flour + pollen grains and sugar solution).

Consequences of Androctonus mauretanicus and Buthus occitanus scorpion venoms on electrolyte levels in rabbits.

Androctonus mauretanicus (A. mauretanicus) and Buthus occitanus (B. occitanus) scorpions, which belong to the Buthidae family, are the most venomous scorpions in Morocco. For the first time, we investigated the effects of such scorpion venoms on serum electrolytes in subcutaneously injected rabbits. For this purpose, 3 groups of 6 albinos adult male rabbits (New Zealand) were used in this experiment. Two of the groups were given a single subcutaneous injection of either crude Am venom (5 μg/kg) or Bo venom (8 μg/kg) whereas the third group (control group) only received physiological saline solution (NaCl 0.9%). The blood samples were collected from injected rabbits via the marginal vein at time intervals of 30 min, 1 h, 2 h, 4 h, 6 h and 24 h after venom injection. The concentrations of electrolytes in the serum samples were measured. Our study indicates that scorpion envenomation in vivo, rabbit animal model, caused severe and persistent hypomagnesaemia and hypochloremia, which are accompanied of hypernatremia, hyperkalemia and hypercalcaemia. The intensity of electrolytes imbalance was clearly superior in the case of A. mauretanicus scorpion venom (although a lower quantity of venom was injected). This is coherent with the experimental data which indicate that A. mauretanicus venom is more toxic than B. occitanus venom.

Relationship between food and venom production in the estuarine stonefish Synanceia horrida

BackgroundThe potential costs of venom production may be significant to many marine venomous taxa. In general, the parameters that influence the rate of venom production are poorly understood, but seem to be related to feeding frequency. MethodsThis study examines the effects of starvation on venom profile and venom yield on the estuarine stonefish (Synanceia horrida). In total, the venom of eight stonefishes was tested under two feeding regimes. Over a four week period, one of the two groups underwent an episode of suspended feeding, while the other was fed on a daily basis. The effect of time on venom replacement was determined by a paired T-test. ANOVA was performed to analyze differences in venom weight between fed and unfed treatments. ResultsNutritional suspension was found to have a significant effect on the quantity of venom produced. SDS-PAGE gel and FPLC revealed that the components of the venom collected from both groups were similar, indicating that four weeks is an adequate time to regenerate key venom components but not replenish initial venom quantities. ConclusionsVenom production was found to be affected by starvation.

Effect of Bee Venom Collecting on The Behavior of Honeybee Colonies

The present investigation studied bee venom collecting effect on the behavior of honeybee colonies such as (Hygienic and hoarding honeybees behavior, queen right and queen less). Hygienic behavior, the positive effect of using bee venom collection method on hygienic behavior, that increased this behavior (22%) of honey bee worker cells, Apis mellifera,while hoarding behavior in honey bees, Apis mellifera L., statistical analysis that there was no significant difference between before and after treatment in four colonies. on the other hand, there was an increase in feed conception after treatment, it that seems to the alarming or stimulation of worker honey bee by electrical impulses from bee venom collector so, it increasing the worker hoarding behavior. The queen less had negative effect on venom quantity, and there was positive relation between the number of combs and venom quantity. The relationship between certain characters of honey bee colonies (i.e. stored pollen, stored honey yield and areas, bee population, brood, and foraging activities) and bee venom produced by electrical impulses and quantity of bee venom which collected from colonies variability at different periods of active season showed significant variations in the venom amounts collected at different periods of active season.

Characterization and Recombinant Expression of Terebrid Venom Peptide from Terebra guttata.

Venom peptides found in terebrid snails expand the toolbox of active compounds that can be applied to investigate cellular physiology and can be further developed as future therapeutics. However, unlike other predatory organisms, such as snakes, terebrids produce very small quantities of venom, making it difficult to obtain sufficient amounts for biochemical characterization. Here, we describe the first recombinant expression and characterization of terebrid peptide, teretoxin Tgu6.1, from Terebra guttata. Tgu6.1 is a novel forty-four amino acid teretoxin peptide with a VI/VII cysteine framework (C–C–CC–C–C) similar to O, M and I conotoxin superfamilies. A ligation-independent cloning strategy with an ompT protease deficient strain of E. coli was employed to recombinantly produce Tgu6.1. Thioredoxin was introduced in the plasmid to combat disulfide folding and solubility issues. Specifically Histidine-6 tag and Ni-NTA affinity chromatography were applied as a purification method, and enterokinase was used as a specific cleavage protease to effectively produce high yields of folded Tgu6.1 without extra residues to the primary sequence. The recombinantly-expressed Tgu6.1 peptide was bioactive, displaying a paralytic effect when injected into a Nereis virens polychaete bioassay. The recombinant strategy described to express Tgu6.1 can be applied to produce high yields of other disulfide-rich peptides.

A simple non-invasive technique for venom milking from a solitary wasp Delta conoideum Gmelin (Hymenoptera: Vespidae)

Prospecting wasp, ant and bee venom for active bio-molecules has gained considerable interest among researchers in recent years. Collecting sufficient quantity of venom from solitary wasps without sacrificing them is often difficult. Here we describe a non-invasive technique for collecting venom from a solitary wasp Delta conoideum Gmelin (Red-backed potter wasp). Venom was milked by presenting an agar block to a single female wasp for stinging. The venom was extracted from the agar block using ACN: water solvent system. The total protein in venom was estimated quantitatively and the presence of peptides in the venom was confirmed by MALDI-TOF analysis. The proposed technique is non-invasive and pure venom can be repeatedly ‘milked’ using this method from other wasps and also bees without the need for sacrificing a large number of individuals.

New Approaches in Monitoring Venom of Genus Dendroaspis

A novel approach to the study of venoms characterizes and compares the venom structure of genus Dendroaspis presented in this work. The complex molecular structure of individual venoms of genus Dendroaspis was defined graphically as a record of synchronous fluorescence fingerprint and atomic force microscopy. Simple comparison of these methods mentioned above of individual analyzed venom samples will immediately reveal changes in each venom composition. Application of these methods with electrophoresis and total protein concentration are new alternatives that were used for monitoring venom composition in selected snakes. Electrophoretogram of black mamba with very low content of total proteins contained the largest number of separated fractions, whereas synchronous fluorescence analysis showed that the highest endogenous fluorescence was found in the venom of black mamba compared with the venom of green mambas, respectively. Our results confirmed different molecular structure in the venom of the genus Dendroaspis. The practical advantages of the selected techniques are high sensitivity and minimal quantity of venom required for the assay. These novel methods show that the least toxic Dendroaspis intermedius contained the greatest amount of proteins contrary to Dendroaspis polylepis with a considerably lower content of proteins but the highest toxic bioactivity.

Extraction of venom and venom gland microdissections from spiders for proteomic and transcriptomic analyses.

Venoms are chemically complex secretions typically comprising numerous proteins and peptides with varied physiological activities. Functional characterization of venom proteins has important biomedical applications, including the identification of drug leads or probes for cellular receptors. Spiders are the most species rich clade of venomous organisms, but the venoms of only a few species are well-understood, in part due to the difficulty associated with collecting minute quantities of venom from small animals. This paper presents a protocol for the collection of venom from spiders using electrical stimulation, demonstrating the procedure on the Western black widow (Latrodectus hesperus). The collected venom is useful for varied downstream analyses including direct protein identification via mass spectrometry, functional assays, and stimulation of venom gene expression for transcriptomic studies. This technique has the advantage over protocols that isolate venom from whole gland homogenates, which do not separate genuine venom components from cellular proteins that are not secreted as part of the venom. Representative results demonstrate the detection of known venom peptides from the collected sample using mass spectrometry. The venom collection procedure is followed by a protocol for dissecting spider venom glands, with results demonstrating that this leads to the characterization of venom-expressed proteins and peptides at the sequence level.

Extraction of Venom and Venom Gland Microdissections from Spiders for Proteomic and Transcriptomic Analyses

Venoms are chemically complex secretions typically comprising numerous proteins and peptides with varied physiological activities. Functional characterization of venom proteins has important biomedical applications, including the identification of drug leads or probes for cellular receptors. Spiders are the most species rich clade of venomous organisms, but the venoms of only a few species are well-understood, in part due to the difficulty associated with collecting minute quantities of venom from small animals. This paper presents a protocol for the collection of venom from spiders using electrical stimulation, demonstrating the procedure on the Western black widow (Latrodectus hesperus). The collected venom is useful for varied downstream analyses including direct protein identification via mass spectrometry, functional assays, and stimulation of venom gene expression for transcriptomic studies. This technique has the advantage over protocols that isolate venom from whole gland homogenates, which do not separate genuine venom components from cellular proteins that are not secreted as part of the venom. Representative results demonstrate the detection of known venom peptides from the collected sample using mass spectrometry. The venom collection procedure is followed by a protocol for dissecting spider venom glands, with results demonstrating that this leads to the characterization of venom-expressed proteins and peptides at the sequence level.

An alternative micromethod to access the procoagulant activity of Bothrops jararaca venom and the efficacy of antivenom

The assessment of the capacity of antivenoms to neutralize the lethal activity of snake venoms still relies largely on traditional rodent lethality assay (LD50). However, adequately validated in vitro tests should be introduced for assessing antivenom neutralizing capacity in plasma of immunized horses as well as for in-process quality control. The dynamic of fibrin formation in recalcified avian plasma samples is extremely slow, when compared to that presented by mammalian plasmas. In this study, we present one new coagulant assay, by performing dose–response curve after plotting the clotting time (CT) parameter of the ROTEM profile of recalcified chicken plasma samples (target) against semi-logarithmic doses of Bothrops jararaca venom (agonist), either in absence or in presence of the semi-logarithmic doses of anti-bothropic serum (ABS) (antagonist).The mean coagulant dose 50% (CD50) was defined as the quantity of venom (in μg) which reduces CT to 900 s, between minimum and maximum responses. The CT induced by 5CD50 of the venom was used as the control for calculating the effective dose (ED) of each batch of ABS. ED was defined as the ABS dose (nanoliters, nL) at which CT induced by one amount of venom corresponding to 5CD50 is displaced to the maximum threshold (1800 s). Five batches of the ABS, previously assayed for their lethality neutralizing activity (ED50) were assayed. The correlation coefficient (r) between both in vitro (ED) and in vivo (ED50) values was 0.87 (p value < 0.05). We propose this micro method as highly sensitive for characterization and quantification of possible procoagulant activity of small doses of snake venoms (nanograms) and for detecting small doses (nanoliters) of specific antibodies against this effect in little volume samples of biological fluids.

Poke but don't pinch: risk assessment and venom metering in the western black widow spider, Latrodectus hesperus

The capacity to assess threat, and modulate defensive behaviour accordingly, is widespread among animals. Although numerous studies have demonstrated that venomous animals possess control of venom expenditure in predatory contexts, few have examined venom metering in defensive contexts. Here, we investigated venom use in the context of threat assessment in the western widow spider, Latrodectus hesperus, a synanthropic, medically relevant species found throughout western North America. In experiment 1, we subjected wild-caught adult females (N = 43) to single (low threat) and repeated (medium threat) prods with a gelatin ‘finger’, and repeated pinches between two gelatin fingers (high threat). Poking at low threat elicited primarily avoidance responses (‘move’ and ‘retract’), repeated prodding at moderate threat stimulated increased silk-flicking, and pinching at high threat provoked significantly more biting. In experiment 2, we pinched spiders (N = 20) to induce bites of three successive targets (parafilm-covered tubes) from which venom could be recovered. Spiders modulated venom expenditure at two levels. First, spiders chose whether to use venom, frequently delivering dry bites (>50% of interactions) independent of venom depletion. Second, spiders metered venom quantity, delivering 1.8-fold more venom per bite when pinched on the body versus a leg, and 2.3-fold more venom when successive target presentations were separated by a lengthy (5 min) compared to a brief (5 s) interval. These findings suggest that spiders make decisions about silk and venom use for defence. Because these weapons are metabolically costly to replace, they represent limited commodities that should be used judiciously.

Fluorescent Profiling of Venom-Selected Cobra Species

ABSTRACT The aim of this paper was to characterize and compare spitting cobras of Africa. The autofluorescence of Naja ashei and Naja nigricollis venoms was investigated by atomic force microscopy and fluorescence analysis. The synchronous fluorescence analysis showed higher endogenous fluorescence of Naja ashei venom in comparison with Naja nigricollis venom. The atomic force microscopy revealed different surfaces of compared venoms as a result of different amounts of proteins. Our results confirmed different structures of Naja nigricollis and Naja ashei venom. The practical advantages of selected techniques are high sensitivity, minimal quantity of venom, and capability to measure the spitting cobra by autofluorescence.

Defensive stinging by Parabuthus transvaalicus scorpions: risk assessment and venom metering

Venom is a metabolically expensive commodity that animals should use judiciously. The venom-metering hypothesis proposes that venomous animals control, or meter, the quantity of venom they deploy during predatory or defensive situations. We sought to clarify experimentally whether the buthid scorpion Parabuthus transvaalicus can regulate defensive venom expenditure based on perceived risk. Scorpions were tested under two threat conditions by inducing them to sting repeatedly a parafilm-covered cup. The high-threat condition involved five sting presentations at 5 s intervals, and the low-threat condition comprised five sting presentations at 5 min intervals. Venom metering appeared to be modulated at three levels: wet versus dry sting, composition of venom injected and volume of venom delivered. Scorpions delivered dry stings more often under the low-threat condition, but in both conditions were more likely to employ wet stings as the threat persisted. Venom appearance changed during successive stings from clear (potassium-rich ‘prevenom’), to opalescent, to milky (protein-rich ‘venom’), with biochemical analyses (protein assay and MALDI-TOF) confirming the compositional changes. However, progression through this sequence depended on quantity of venom expended, with milky secretion appearing only after the limited quantity of clear secretion was exhausted (i.e. composition and volume covaried). Scorpions injected approximately two-fold more venom per sting during the high-threat compared to the low-threat condition, with milky venom appearing more quickly within the sequence of five stings for the high-threat condition. Thus, these scorpions perceive risk and regulate venom expenditure during stinging according to level of threat, providing further support for the venom-metering hypothesis.