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Skin lesions in barracks: consider community-acquired methicillin-resistant Staphylococcus aureus infection instead of spider bites.

Recent outbreaks of mysterious skin lesions on multiple personnel at several military facilities were initially blamed on spiders. Requests were made for pest inspection and control to remedy the situation. Greater scrutiny of the situation led to a hypothesis that instead of spiders, an infectious outbreak of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) should be investigated as the etiology. Subsequent culturing of the lesions on personnel at one facility confirmed this bacterial etiology. Barracks, as well as other close quarter military living conditions, are ripe environments for the establishment, persistence, and spread of CA-MRSA. Military medical personnel should consider CA-MRSA as a more likely etiologic agent than spider bites for cutaneous eruptions in which there are multiple lesions on one person or multiple patients with similar lesions.

Animals↗

Brown recluse spider bite. A literature review and case report.

A review of the literature on brown recluse spider bite is presented, including clinical presentation and treatment. Emphasis is placed on the treatment of local tissue necrosis. A case report of a severe necrotic ulcer secondary to a spider bit is presented. Tissue necrosis following a brown recluse spider bit can be debilitating, and healing may be prolonged for many months. Even with early treatment, prognosis often is poor. Future studies might help establish better treatment regimens.

Humans↗

Spider prey (Araneae) of Trypoxylon (Trypargilum) rogenhoferi (Hymenoptera: Sphecidae) in southeastern Brazil.

Fifty five nests and 216 cells of Trypoxylon (Trypargilum) rogenhoferi were obtained from trap-nests (cut bamboo canes) in Santa Carlota Farm (Itaoca Section = IS and Santana Section = SS), Cajuru and on the São Paulo University Campus, Ribeirão Preto (= RP), both in the State of São Paulo, Brazil (Sept. 1993-Oct. 1995). The prey (spiders) of 40 cells from IS, 58 from SS and 39 from RP were identified. The greatest nesting frequency occurred during the hot and wet season (September to April). T. rogenhoferi preyed upon individuals of five spider families, with Araneidae (orb-weaver spiders) being the most frequent (99.6%). Alpaida aff. negro (58%) was the most frequently collected species in IS, followed by A. alto (24.8%); in SS (59.6%) and RP (64.7%) the most frequent species was A. veniliae, followed in SS by A. aff. negro (14.9%) and in RP by A. leucogramma (13.5%). The size of reproductive niches, H' = 1.25 (IS), H' = 1.30 (SS) and H' = 1.29 (RP) were not significantly different. There was a positive correlation between the reproductive niche width (H') and evenness.

Animals↗

Inhibition of the spider heartbeat by gravity and vibration.

The rate and vigor of the spider heartbeat is controlled by an external pacemaker. A mechanical feature of the spider cardio-vascular system is the production of high serum pressure in the prosoma and the legs. This appears to be the source for leg extension. The lyriform organ on the patella of the leg is sensitive to vibratory and kinesthetic stimuli. This sensitivity depends upon the degree of leg extension. Thus the activity of the heart and the response characteristics of the sense receptor are related. The effect of a supra-threshold vibratory or gravitational stimulus is to produce an inhibition and a tachycardia of the spider heartbeat.

Adhesives↗

Inhibition of sodium channels in rat dorsal root ganglion neurons by Hainantoxin-IV, a novel spider toxin.

The effects of Hainantoxin-IV (HNTX-IV), a neurotoxic peptide isolated from the venom of the Chinese bird spider Seleconosmia hainana, on the adult rat dorsal root ganglion (DRG) neurons were investigated. Using the whole-cell patch-clamp technique HNTX-IV inhibited mammal neural TTX-sensitive (TTX-S) sodium currents evidently but the toxin failed to affect TTX-resistant (TTX-R) ones. The inhibition of HNTX-IV is dose-dependent with the IC(50) value of 44.6 nmol/L. The toxin didn't affect the activation and inactivation kinetics of sodium currents, but it caused a 10.1 mV hyperpolarizing shift in the voltage midpoint of steady-state sodium channel inactivation on DRG neurons. The results indicated that HNTX-IV, a novel spider toxin, maybe alternate voltage-gated sodium channels through a mechanism distinct from other spider toxins such as delta-ACTXs, mu-agatoxins I-VI which targeted the receptor site 3 to slow the inactivation kinetics of sodium currents.

Animals↗

[Amplification, cloning and sequence analysis of spider dragline silk cDNA].

Spider dragline silk is synthesized in special gland named major ampulate (MA) gland. The MA glands were dissected from the abdomen of the spiders Nephila clavata and the total RNA was extracted by the TRIZOL. The cDNA of dragline silk was amplificated by RT-PCR (reverse transcription polymerase chain reaction), multiplex PCR and cloned. PCR identification, restriction analysis and DNA sequence analysis were carried out to verify the recombinant plasmids. The codon usage frequencies of the cloned cDNA were added up, and the predicted amino acid sequence was compared with Spidroin2 of Nephila clavipes. Predicted secondary structure of the predicted amino-acid sequence was analysized by DNAStar software. All results showed that the cloned cDNA we got (GenBank Accession No. AF441245) was the very fragment of spider dragline silk Spidroin2 cDNA.

Amino Acid Sequence↗

[Production and application of rabbit anti-imitative spider dragline silk protein polyclonal antibody].

A synthetic spider dragline gene s600 was cloned into fusion protein expression vector pGEX-KG and expressed in Escherichia coli. Protein S600 was purified and rabbit antiserum was prepared. Amino acid composition analysis confirmed the right expression of S600. Western blot analysis revealed that anti-S600 antiserum could react with natural spider silk, so the synthetic dragline protein, designed by the authors, shares similar immunological characteristics with the natural spider silk. An ELISA system was also established for the quantitative detection of synthetic dragline protein expression in silk gland (or in the cocoon) of transgenic silkworm.

Animals↗

[Biological synthesis and purification of spider dragline silk protein polymers containing RGD three peptide].

Spider dragline silk is one of most perfect fibrous proteins in nature. As biomaterials, it has a wide application in tissue engineering due to its unique mechanical properties, good biocompatibility, slow degradation. In this paper, based on the highly repetitive sequence of spider dragline silk and with the introduced RGD peptide codons which involve cell adhesion, the DNA monomer sequence encoding RGD-spider dragline silk was synthesized, and then was used to construct the multimers by the strategy of "head to tail"; the multimers were ligated into prokaryotic expression vector pET-30a, and then the B121 (DE3) pLyS, were transformed the expression of recombinant protein was induced by the addition of IPTG. SDS-PAGE analysis shows that the molecular weight of products expressed here are 35KD and 60KD respectively in agreement with the desired. Western assay was used for determining the specification of products. Further, the purification process was groped for the producing of large quantity of synthetic proteins through high density fermentation.

Amino Acid Sequence↗

Observations on life cycle of certain spiders from Western Ghats of Tamil Nadu.

Survey was conducted, in the different forests ecosystems of Western Ghats of Tamil Nadu in Nilgris, Coimbatore, Erode, Virudhunagar and Tirunelveli districts to collect the adult spiders and study them taxonomically. Fifty-six species of spider collections were made. From the fifty six, biology was studied for six spider species, such as Micrommata virescens n.sp., Oxyopes javanus, Peucetia virridana, Agelena kariansholensis n.sp., Heteropoda venatoria and Olios hampsoni. Biology studies with Peucetia virridana and Micrommata virescens showed that both species took more than 350 days to complete their life cycles. Heteropoda venetoria and Oxyopes javanus took more than 250 days to complete their life cycle. Agelena kariansholensis took 381 days and Olios hampsoni took 345 days to complete their life cycles. 30% of Peucetia virridana and more than 20% of Heteropoda venatoria and Micrommata virescens and 7% of Oxyopes javanus developed into adults in captivity.

Animals↗

[Brown spider bite].

The diagnosis of bite by the brown recluse spider, Loxosceles reclusus, is rarely based on absolute identification of the insect because the victims are usually bitten while sleeping or dressing. More often, the history, clinical findings and course of the bite lead to the diagnosis. For early confirmation up to 24 hours after the bite, the passive hemagglutination test can be used. For older lesions, the in-vitro lymphocyte transformation test is useful, but is available in only a few medical centers. Treatment of the bite of the brown recluse spider varies from conservative to more active approaches. Resting, local cooling, systemic antibiotics to prevent infection and mild anti-inflammatory drugs may be given. In the more active approach oral corticosteroids are added in the first 72 hours to the antibiotics, especially in massive bites with necrotic centers greater than 2 cm in diameter, or when there is systemic loxoscelism. Recently, good results have been reported with Avlosulfon (dapsone), which is claimed to cure necrotic cutaneous ulcerations, presumably by reducing the activity of polymorphonuclear leukocytes. Other treatments include specific antivenin, (of limited use because it must be administered shortly after the bite), and surgery to prevent spreading of the venom. We describe 3 cases of brown spider bite with typical clinical presentations in adults aged 20-40 years. 2 were treated with corticosteroids and antibiotics and 1 with Avlosulfon and prednisone, all within 72 hours of the bite. 2 recovered completely within a few days, but the third treated with prednisone and antibiotics, developed an ulcer which healed only after several months of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Cortex Hormones↗

The channel-forming component of the Theridiidae spider venom neurotoxins.

It is known that Steatoda (Lityphantes) paykulliana and Latrodectus mactans tredecimguttatus spider venoms are toxic to mammals and insects. These venoms act presynaptically eliciting massive release of transmitters. They also form channels in bilayer lipid membranes (BLM) that are selective for cations. Venoms of both spider species were fractionated by gel filtration on a Sephadex G-100 column. The fraction obtained were tested on neuromuscular preparations of frog and locust and on BLM. A fraction of low molecular weight components (about 5000 daltons and less) was disclosed. This fraction showed presynaptic and channel-forming effects similar to those of crude venoms and of high molecular weight toxin fractions, obtained simultaneously from these venoms. It was shown that channels formed in BLM by crude venoms and its different fractions are identical. Also, it was found that the low molecular weight channel-forming component is a construction element of high molecular weight toxins. On the basis of data obtained a toxin structure model of the Theridiidae family spider venoms was proposed.

Animals↗

Fine structure of a spider joint receptor and associated synapses.

The fine structure of a joint receptor (R10) in a spider leg (Zygiella x-notata) was examined with light and electron microscopy. The R10 receptor consists of a compact ganglion which is situated near the dorsal joint membrane of the femur/patella joint. Each of the ten sensory cells comprising the ganglion sends one branching dendrite into the hypodermis underlying the joint membrane. All dendritic branches together form a sheet-like meshwork 50 microns wide and 1 microns thick, which is traversed obliquely by hypodermis cells. When the joint is stretched shearing forces are apparently transmitted to the receptive dendritic branches via microtubular bundles inside the hypodermis cells. The soma and dendrites of the sensory cells receive numerous synaptic input from presumably efferent fibres. The fine structure of these synapses is described and compared with other peripheral and central spider synapses. All R10 synapses contain small synaptic vesicles (32 nm diameter), whereas motor endplates possess large vesicles (38 nm). Central synapses have two significantly different vesicle populations which are either of the small or large variety. Since synapses with small vesicles are supposedly inhibitory, receptor cells in spiders might be under efferent control. Such a system is unknown in insects or crustaceans, but may be typical for arachnids.

Animals↗

Slowly-reversible block of glutamate receptor-channels by venoms of the spiders, Argiope trifasciata and Araneus gemma.

Venom from two species of spider has been tested on the locust glutamatergic nerve-muscle system. The neurally-evoked twitch contraction of locust metathoracic retractor unguis muscle was abolished in the presence of venom and only slowly recovered following its removal. The twitch inhibition onset rate was venom concentration and stimulation frequency dependent. The mechanical response of this muscle to L-glutamate was also inhibited by spider venom. Complete abolition of the potential evoked by ionophoresis of L-glutamate to excitatory junctions on locust metathoracic extensor tibiae muscle was obtained with low concentrations of venom and recovery on washing was either slow and incomplete or not evident. The ionophoretic studies and twitch contraction studies indicate that the venom acts only when the glutamate receptor channel complex is activated by agonist. This conclusion is supported by data of the effects of venom on the voltage clamped excitatory postsynaptic current recorded from locust extensor tibiae muscle. Preliminary attempts to identify and isolate the active principles in these spider venoms indicate that activity is restricted to a molecule(s) of low (less than 1000 dalton's) molecular weight.

Animals↗

Red-back spider envenomation in the red centre of Australia.

OBJECTIVE: To examine the incidence, symptoms and treatment of red-back spider envenomation at a rural hospital. METHODS: A retrospective review of all patients admitted to the intensive care unit of Alice Springs Hospital with red-back spider envenomation from 1 January 1991 until 31 December 1992. RESULTS: Thirty-two patients were identified, of whom 12 were Australian Aboriginals (35%). Mean time from bite to presentation was 21 hours. Twenty-six patients required antivenom. All patients responded well to therapy and adverse reactions to the antivenom were observed. Two antivenom recipients had had previous bites requiring treatment. Aboriginals received antivenom later than non-Aboriginals (27.0 h v. 16.5 h) and this delay was associated with more sweating and fever in Aboriginals. CONCLUSION: Red-back spider envenomation is common in Central Australia. Aboriginals and non-Aboriginals are equally at risk but later presentation is more common in Aboriginals who thereby suffer greater systemic symptoms. Antivenom use is safe and effective.

Adolescent↗

Black widow spider bites.

Black widow spiders (Latrodectus species) are found worldwide. Envenomation of humans usually occurs as the result of chance intrusion into the spider's domain by the human. The venom is regarded as one of the most potent biologic toxins. The venom acts by destabilization of cell membranes and degranulation of nerve terminals resulting in the release of neurotransmitters. The clinical picture is characterized by painful muscle spasm and hypertension. The very young, the elderly or enfeebled, and those with cardiovascular disease are at greatest risk. While not always necessary, the most effective treatment is specific antiserum. Muscle relaxants, analgesics and intravenous calcium are useful adjuvant treatment.

Adult↗

Spiders in Brazil.

Descriptions of the principal venomous spiders in Brazil, of the genera Phoneutria, Loxosceles, Latrodectus and Scaptocosa, are given, together with a list of species and their geographical distribution. Detailed information on their habitat, behaviour and venom quantity, symptomatology of human accidents and epidemiology is given and recommendations are made for the prevention of accidents. General observations are made on the most common mygalomorph spiders.

Animals↗

Evidence for a high molecular weight pre-robustoxin molecule in the venom of the male Sydney funnel-web spider (Atrax robustus).

Robustoxin is the lethal polypeptide toxin in Atrax robustus venom. A monoclonal antibody was produced using synthetic, unfolded robustoxin conjugated to keyhole limpet haemocyanin as the immunogen. This monoclonal antibody did not protect newborn mice against challenge with the crude venom of the male Sydney funnel-web spider, but did slightly prolong their survival time. Western blotted crude venom of the male Sydney funnel-web spider showed two monoclonal antibody binding bands. One band at low M(r) corresponded to robustoxin (M(r) 4854), while the other higher M(r) band (approximately 37,000) may be due to a pre-robustoxin molecule.

Adjuvants, Immunologic↗

ELISA for the detection of venom antigens in experimental and clinical envenoming by Loxosceles intermedia spiders.

Enzyme linked immunosorbent assays (ELISA) were developed to detect antigens from Loxosceles intermedia spider venom. Hyperimmune horse anti-Loxosceles intermedia IgGs were prepared by immunoaffinity chromatography and used to set up a sandwich-type ELISA. The specificity of the assay was demonstrated by its capacity to correctly discriminate the circulating antigens in mice that were experimentally inoculated with L. intermedia venom from those inoculated with L. gaucho, L. laeta, and Phoneutria nigriventer spider venoms, Tityus serrulatus scorpion venom and Bothrops jararaca, Crotalus durissus terrificus, Lachesis muta muta and Micrurus frontalis snake venoms. Measurable absorbance signals were obtained with 0.8 ng of venom per assay. The ELISA also detected antigens in the sera of patients envenomed by L. intermedia. Therefore, after standardization for clinical use this ELISA may be a valuable tool for clinicians and epidemiologists.

Adult↗