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PubMed2002

Molecular cloning, expression and immunological properties of LiD1, a protein from the dermonecrotic family of Loxosceles intermedia spider venom.

The present report describes the identification and molecular characterization of LiD1, a protein expressed in the venom gland of the brown spider Loxosceles intermedia. LiD1 belongs to a family of proteins with dermonecrotic activity and members of this family have been found in spiders from the genus Loxosceles. The necrotic lesions caused by this group of proteins may lead to serious socio-economic problems such as surgical tissue reconstitution and even patient death. LiD1 was cloned using a cDNA library constructed from the venom gland of L. intermedia and antibodies against proteins with dermonecrotic activity isolated from the crude venom of this spider. The amino acid sequence deduced from the cDNA revealed a mature protein of approximately 31 kDa, with a pI of 7.37. The cDNA also revealed the existence of a signal peptide, a propeptide and also an untranslated 3' region with 218 nucleotides. LiD1 was expressed as a protein fused with beta-galactoside protein using the vector pBK-CMV, resulting in the recombinant protein recLiD1 with important immunological properties. recLiD1 was strongly recognised by anti-dermonecrotic antibodies and was also able to generate reactive antibodies against native dermonecrotic proteins isolated from the venom of L. intermedia.

Amino Acid Sequence↗
PubMed1998

Pathological changes induced by PhTx1 from Phoneutria nigriventer spider venom in mouse skeletal muscle in vitro.

The 'armed' spider Phoneutria nigriventer is responsible for most human accidents involving spiders in Brazil. The effects of fraction Tx1 (PhTx1) from the venom of this spider were investigated by physiological and morphological methods using the mouse phrenic nerve-diaphragm preparation. PhTx1 (1 and 5 microg) did not affect the twitch tension of muscle fibers under indirect electrical stimulation. At this same concentration, PhTx1 also did not alter the miniature end-plate potential (mepp) frequency and amplitude, nor did it change the resting membrane potential 60 min after addition to the preparation. Light microscopy (LM) revealed that in muscles incubated with PhTx1 a number of fibers were morphologically altered, as evidenced by microvacuolization and myofibril hypercontraction and loss within 15 min after toxin administration. Transmission electron microscopy (TEM) showed sarcoplasmic reticulum swelling, disorganization of the sarcomeres and mitochondrial damage, and occasionally, sarcolemmal discontinuities with a persisting basal membrane. The intra-muscular fascicles of the phrenic nerve showed myelinated axons with vacuolated myelin sheaths as well as peri- and intra-axoplasmic vacuoles. The neuromuscular junction changes were variable, but were rarely severe. Thus, although PhTx1 did not depolarize or hyperpolarize the neuromuscular junction, it was nevertheless toxic to a restricted number of muscle fibers and nerve structures. The site of action of PhTx1 may involve the sarcolemma and axolemma as suggested by the morphological abnormalities which could reflect hydroelectrolytic disturbances.

Animals↗
PubMed1999

Ontogenetic development of Loxosceles intermedia spider venom.

Envenomation by Loxosceles spider has become a public health problem in the South region of Brazil, mainly due to high levels of domiciliary infestation by Loxosceles intermedia spiders. The toxic effects of L. intermedia venom are mostly associated with a 35 kDa protein (F35) which presents complement-dependent haemolytic and dermonecrotic activities. The aim of this study was to detect, through biological and immunochemical assays, the appearance of the main toxic component, F35, during the ontogenetic development of L. intermedia spiders. The toxin appeared in its fully active form in venom of third instar spiderlings; from then on its activity increased throughout development until adulthood. On the other hand, F35 was not detected in extracts of either eggs or spiderlings of the first and second instars.

Administration, Cutaneous↗
PubMed2000

Brown recluse spider bite to the eyelid.

PURPOSE: To present a photographically documented case of a known brown recluse spider bite to the eyelid. DESIGN: Interventional case report. METHODS: The wound was photographed daily during an 11-day hospitalization and at 1 month and 6 months after the injury. Treatment included canthotomy and cantholysis; administration of dapsone, antibiotics, and steroids; and hyperbaric oxygen therapy. MAIN OUTCOME MEASURES: Clinical presentation and course of a known brown recluse spider bite. RESULTS: Complete recovery with cicatrization at the site of the bite. CONCLUSIONS: We present a case of a brown recluse spider bite to the left lower eyelid with a discussion of management and outcome of this rarely reported injury.

Animals↗
PubMed2002

Mechanism of induction of complement susceptibility of erythrocytes by spider and bacterial sphingomyelinases.

We have recently shown that the sphingomyelinase toxins P1 and P2 from the venom of the spider Loxosceles intermedia induce complement (C)-dependent lysis of autologous erythrocytes by induction of the cleavage of cell surface glycophorins through activation of an endogenous metalloproteinase facilitating the activation of the alternative pathway of C. Phospholipase D (PLD) from Corynebacterium pseudotuberculosis shows some degree of homology with the spider sphingomyelinases and can induce similar clinical symptoms to those observed after spider envenomation. The aim of this study was to investigate if the bacterial PLD-induced haemolysis of human erythrocytes was C dependent and if cleavage of glycophorins occurred. We show here that haemolysis of both PLD- and P1-treated human erythrocytes was C dependent, but while PLD-mediated haemolysis was dependent on activation of the classical pathway of C, P1 induced lysis via both the classical and alternative pathways. P1, but not PLD, induced cleavage of glycophorins and no change in expression of complement regulators was induced by either of the toxins. In both cases, annexin V binding sites were exposed, suggesting that the membrane asymmetry had been disturbed causing exposure of phosphatidylserine to the cell surface. Our results suggest that C susceptibility induced by L. intermedia and C. pseudotuberculosis PLD is a result of exposure of phosphatidylserine, and the higher potency of P1 toxin can be explained by its additional effect of cleavage of glycophorins.

Animals↗
PubMed2002

Histopathological findings in rabbits after experimental acute exposure to the Loxosceles intermedia (brown spider) venom.

Loxoscelism, the term used to describe envenomation with brown spiders, is characterized by a dermonecrotic lesion at the bite site. In the present investigation we submitted albino rabbits to an acute experimental envenomation protocol using Loxosceles intermedia (brown spider) venom, with in order to determine the pathogenesic features of the lesion induced by this spider, which is the cause of several accidents throughout the world. Rabbits received intradermal injections of the venom and were monitored over the first 4 h, and then at 12 h and 1, 2 and 5 days after envenomation. Histological specimens from 3 rabbits per time point were collected from euthanized animals and processed for histological examination by light microscopy. Major findings observed during the first 4 h were oedema, haemorrhage, degeneration of blood vessel walls, plasma exudation, thrombosis, neutrophil accumulation in and around blood vessels with an intensive diapedesis, a diffuse collection of inflammatory cells (polymorphonuclear leucocytes) in the dermis, and subcutaneous muscular oedema. Over the following hours and up to 5 days after envenomation the changes progressed to massive neutrophil infiltration (with no other leucocytes) into the dermis and even into subcutaneous muscle tissue, destruction of blood vessels, thrombosis, haemorrhage, myonecrosis, and coagulative necrosis on the 5th day.

Animals↗
PubMed2001

Venom from Anemesia species of spider modulates high voltage-activated Ca(2+) currents from rat cultured sensory neurones and excitatory post synaptic currents from rat hippocampal slices.

The actions of crude venom from Anemesia species of spider were investigated in cultured dorsal root ganglion neurones from neonatal rats and hippocampal slices. Using mass spectrometry (MALDI-TOF MS), 10-12 distinct peptides with masses between about 3 and 10kDa were identified in the crude spider venom. At a concentration of 5 microg/ml crude Anemesia venom transiently enhanced the mean peak whole cell voltage-activated Ca(2+) current in a voltage-dependent manner and potentiated transient increases in intracellular Ca(2+) triggered by 30mM KCI as measured using Fura-2 fluorescence imaging. Additionally, 5-8 microg/ml Anemesia venom increased the amplitude of glutamatergic excitatory postsynaptic currents evoked in hippocampal slices. Omega-Conotoxin GVIA (1 microM) prevented the increase in voltage-activated Ca(2+) currents produced by Anemesia venom. This attenuation occurred when the cone shell toxin was applied before or after the spider venom. Anemesia venom (5 microg/ml) created no significant change in evoked action potentials but produced modest but significant inhibition of voltage-activated K(+) currents. At a concentration of 50 microg/ml Anemesia venom only produced reversible inhibitory effects, decreasing voltage-activated Ca(2+) currents. However, no significant effects on Ca(2+) currents were observed with a concentration of 0.5 microg/ml. The toxin(s) in the venom that enhanced Ca(2+) influx into sensory neurones was heat-sensitive and was made inactive by boiling or repetitive freeze-thawing. Boiled venom (5 microg/ml) produced significant inhibition of voltage-activated Ca(2+) currents and freeze-thawed venom inhibited Ca(2+) transients measured using Fura-2 fluorescence. Our data suggest that crude Anemesia venom contains components, which increased neuronal excitability and neurotransmission, at least in part this was mediated by enhancing Ca(2+) influx through N-type voltage-activated Ca(2+) channels.

Action Potentials↗
PubMed2026

Reference genome of the Californian trapdoor spider Aptostichus stephencolberti Bond 2008 (Araneae: Mygalomorphae: Euctenizidae).

We present a reference genome assembly for the trapdoor spider Aptostichus stephencolberti. This species, described in 2008, is endemic to the highly fragmented coastal dune habitats of Northern California from Monterey to the San Francisco Bay Area. Trapdoor spiders are ideal taxa for landscape scale genomic studies owing to their extreme site fidelity and limited dispersal capabilities; these same characteristics make them prone to extinction. Genomic studies of species like A. stephencolberti can reveal novel areas of endemism and high conservation value that may not be evident in species with wider ranges and greater dispersal capabilities. As part of the California Conservation Genomics Project, we constructed the A. stephencolberti reference genome from high quality long-read sequences, scaffolded with proximity ligation Omni-C data. The primary assembly comprises 551 scaffolds spanning 3.63 Gbp, a scaffold N50 of 62.2 Mbp and BUSCO completeness of 95.6%. We estimate 52 chromosomes yet find no (TTAGG)n telomer repeats. Expanding the telomeric repeat search finds an ancestral loss of the repeat from all spiders. Automated annotation using the NCBI refseq pipeline and RNAseq data from whole adults finds 14,067 genes with a BUSCO annotation completeness of 95.56%. Repeat annotation identified 77% of the genome to be interspersed repeats. This resource, the first for family Euctenizidae will facilitate future study and resulting conservation actions of A. stephencolberti and other Aptostichus sp. populations associated with the rapidly changing California coastal dune ecosystem.

Aptostichus stephencolberti↗
PubMed1990

Persistent segmental cutaneous anesthesia after a brown recluse spider bite.

Patients with brown recluse spider bites commonly suffer from pain, muscular aching, and a variety of local dysesthesias during the acute and resolution phases of toxin-induced injury. This is our first well-documented observation of persistent cutaneous anesthesia caused by a spider bite. The anesthetic area conformed to the distribution of a specific nerve, the transverse cervical cutaneous nerve. The identification of the spider as a brown recluse and the location of the bite over the nerve's usual pathway strongly suggest that the venom was responsible for this complication.

Adult↗
PubMed1984

Interaction of brown recluse spider venom on cell membranes: the inciting mechanism?

The venom from the brown recluse spider, Loxosceles reclusa, contains one or more factors which produce skin necrosis. A dermonecrotic factor with sphingomyelinase D activity was purified from the spider's venom sacs which produced skin necrosis when injected intradermally in rabbits. Adsorption of the dermonecrotic activity occurred following incubation with isolated membranes from different cell types or different species in a dose-responsive fashion. Since injection of the complex in rabbits produced skin necrosis, a specific antibody that inhibits the dermonecrotic activity and sphingomyelinase activity was used to identify the venom fraction on the plasma membrane of erythrocytes with electron microscopy. Initiation of cutaneous inflammatory reaction may result from high-affinity interaction of a venom component in the brown recluse spider venom and cell membranes.

Adsorption↗
PubMed1983

Tetanus and botulinum toxins inhibit, and black widow spider venom stimulates the release of methionine-enkephalin-like material in vitro.

The actions of tetanus toxin, botulinum A toxin, and black widow spider venom on the release of methionine-enkephalin-like immunoreactivity have been studied; a particulate fraction prepared from rat striata was used. Depending on the duration of preincubation, tetanus toxin diminished the release evoked by veratridine (50 microM final concentration), and abolished it at final concentrations between 0.1 and 1 micrograms/ml. Botulinum A toxin was about 10 to 20 times less potent. Heating or pretreatment with antitoxin inactivated the clostridial toxins. The particulate fraction pretreated with V. cholerae neuraminidase retained its toxin sensitivity. Tetanus toxin also depressed the release due to sea anemone toxin II and high K+. Spider venom stimulated the release in a concentration-dependent manner and required the presence of Ca2+; its effects were depressed by tetanus toxin. These results support the view that both clostridial toxins and spider venom act as broad-range presynaptic neurotoxins on peptidergic transmitter systems.

Animals↗
PubMed2005

A double-blind, randomized trial of intravenous versus intramuscular antivenom for red-back spider envenoming.

OBJECTIVE: To compare the efficacy of intravenous versus intramuscular antivenom (AV) in the treatment of Red-back spider (RBS) envenoming. METHODS: Randomized, double-dummy, double-blind, multicentre trial of patients with red-back spider envenoming requiring AV treatment recruited from five hospital EDs in Western Australia. RESULTS: Thirty-five patients were recruited; two were excluded; 33 were available for initial analysis, but two who were unblinded after one ampoule of trial AV and given i.v. AV had limited data; 31 remained in the study and had more complete data. After AV, pain scores for both i.m. and i.v. groups improved rapidly. At 24 h, the i.v. group was better with a 55% absolute difference (76% vs. 21%; 95% CI 25-85% difference) in the proportion pain-free. There were no safety issues. CONCLUSIONS: Red-back spider antivenom was initially effective by both i.m. and i.v. routes. The study generates the hypothesis that at 24 h, significantly more patients are pain-free with i.v. administration. Definitive recommendations on the optimal route of administration of RBS AV await the results of further studies.

Adolescent↗
PubMed1994

Analyses of metal ions in spider venoms in relation to insecticidal activity of clavamine.

To elucidate insecticidal activity of spider toxins, metal ions in venoms and in the bodies were determined by thin layer chromatography, spark source mass spectrometry, ion chromatography, inductively coupled plasma emission spectrometry and atomic absorption spectrometry. Two kinds of spiders were used, Nephila clavata and Nephila maculata. Metals from their venom glands were extracted with hydrochloric acid and the metal concentrations were almost the same in the two species. Many kinds of metals, Fe, Zn, Pb, Cu, Ca, Mg, Na, P and S were found at higher levels in the venoms at concentrations higher than in the bodies. The contents of metal ions were low in the dragonfly and the cicada which are considered to be preys. Clavamine, the main insecticidal component in N. clavata, was effective on larvae of a mosquito with Ca2+, Fe3+ or Pb2+, but ineffective with Mg2+, Zn2+, Fe2+ or Cu2+. It is suggested that the metal chelates play an important role in the intoxication and detoxication of the spider toxins.

Animals↗
PubMedDate not supplied

Management of brown recluse spider bites in primary care.

BACKGROUND: Treatment of brown recluse spider bites remains controversial; there are multiple options but little evidence of their effectiveness. METHODS: Over a 5-year period, family physicians enrolled consecutive patients with suspected brown recluse spider bites. Usual care was provided based on physician preferences. Topical nitroglycerine patches and vitamin C tablets were provided at no cost for those who wished to use them. Baseline data were collected, and patients were followed-up weekly until healing occurred. Outcome measures included time to healing and occurrence of scarring. Regression methods were used to evaluate the impact of the 4 main treatment approaches (corticosteroids, dapsone, topical nitroglycerine, and high-dose vitamin C) after controlling for bite severity and other predictors. RESULTS: Two hundred and sixty-two patients were enrolled; outcomes were available for 189. The median healing time was 17 days. Only 21% had permanent scarring. One hundred seventy-four received a single treatment modality. Among this group, 12 different modalities were used. After controlling for other variables, predictors of more rapid healing included lower severity level, less erythema, and less necrosis at time of presentation, younger age, no diabetes, and earlier medical attention. Systemic corticosteroids and dapsone were associated with slower healing. Predictors of scarring were higher severity, presence of necrosis, and diabetes. Dapsone was associated with an increased probability of scarring. CONCLUSIONS: We found no evidence that commonly used treatment approaches reduced healing time or the likelihood of scarring in suspected brown recluse spider bites.

Administration, Cutaneous↗
PubMed1995

An outbreak of venomous spider bites in a citrus grove.

An outbreak of necrotizing spider bites in citrus groves in the Aravah valley of southern Israel is reported. Bites were clinically diagnosed to be due to the brown recluse spider Loxosceles rufescens (Dufour, 1820) (Loxoscelidae), one of the most common spiders identified in the groves. The distribution of L. rufescens in this area appears to be restricted to one locality, suggesting that it was a point introduction. This report suggests a previously unreported risk for workers in citrus groves and describes an ecologic intervention consisting of tree pruning and clearing of ground cover that appears to have been successful in reducing the incidence of bites.

Adult↗
PubMedDate not supplied

Funnel-web spider (Atrax robustus) antivenom in the treatment of human envenomation.

Envenomation by the Sydney funnel-web spider may lead to serious illness or death. After an antivenom which had been raised in rabbits was proven to reverse the signs of envenomation in animals, a trial was conducted in patients. Nine patients (aged 3-82 years) with severe envenomation by funnel-web spiders received treatment with an antivenom to the venom of Atrax robustus. Concomitant diseases in the victims included rheumatoid arthritis, diabetes mellitus, complete heart block, pyrexia of unknown origin, and carcinoma of the ovary, which were being treated with appropriate drugs. Because of the introduction of the antivenom, the syndrome which previously caused either death or a hazardous illness which required two to three weeks of hospital care now became an illness lasting one to three days. So far there have been no definite adverse reactions to the antivenom. There have been no deaths since the antivenom has been used, and it is hoped that human fatalities as a result of funnel-web spider envenomation will become a thing of the past.

Adolescent↗
PubMed1999

The clinical characteristics of brown recluse spider bites treated by family physicians: an OKPRN Study. Oklahoma Physicians Research Network.

BACKGROUND: The brown recluse spider (Loxosceles reclusa) has been recognized as a cause of necrotizing bites since at least 1957, but most of the literature consists of laboratory studies using animals, human sera, or case reports of more dramatic examples of bite reactions. Our goal was to develop a more comprehensive clinical description of the brown recluse spider bites treated by family physicians. METHODS: Two preprinted, postage-paid cards were given to physician members of the Oklahoma Physicians Research Network. One card was used for recording examination and treatment data, and the other was for tracking the progress of the bite until it was completely healed. For comparison, similar information was collected from the local poison control center. RESULTS: From April 1996 to August 1998, the physicians recorded 149 bites. Most of the victims were women aged 18 to 65 years, and most sought treatment within 3 days. Pain was common but not universal. Most bites were located on the extremities. Erythema was always present, but necrosis was present in only 40% of the bites. Some systemic signs or symptoms were common. The most frequent forms of treatment were systemic antibiotics (66% of cases) and conservative wound management (56%). Only 1 hospitalization occurred; 43% of the bites healed within 2 weeks; and only 13% resulted in scarring. CONCLUSIONS: The brown recluse spider bite is a relatively common problem treated by family physicians in Oklahoma. Most bites are not serious. More research at the practice level is needed to develop diagnostic criteria and to explore the effectiveness of various treatment options.

Adolescent↗
PubMed1999

Acute and recurrent skin ulceration after spider bite.

We reviewed the records of the Australian Venom Research Unit and The Alfred Hospital Department of Hyperbaric Medicine from January 1992 to July 1998 and found 15 cases of skin ulceration after spider bite that could be followed up with the patient and the treating physician. Fourteen patients had skin ulceration attributed to white-tailed spider bites but in only three was this confirmed. One patient had skin necrosis after a confirmed black house spider bite. Recurrent skin ulceration occurred in nine of the 15 patients.

Adult↗