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F H Matsubara, G O Meissner, V Herzig, H C Justa, B C L Dias, D Trevisan-Silva, L H Gremski, W Gremski, A Senff-Ribeiro, O M Chaim, G F King, S S Veiga
Loxosceles intermedia venom comprises a complex mixture of proteins, glycoproteins and low molecular mass peptides that act synergistically to immobilize envenomed prey. Analysis of a venom-gland transcriptome from L. intermedia revealed that knottins, also known as inhibitor cystine knot peptides, are the most abundant class of toxins expressed in this species. Knottin peptides contain a particular arrangement of intramolecular disulphide bonds, and these peptides typically act upon ion channels or receptors in the insect nervous system, triggering paralysis or other lethal effects...
October 15, 2016: Insect Molecular Biology
F Boissiere, R Masson, S Fluieraru, J Vitse, L Dessena, M Lefevre, F Bekara, C Herlin
INTRODUCTION: Loxosceles spiders are ubiquitous and responsible for many cases of envenomation in the world. The kind rufescens is present in the Provence and Occitan regions in France. During the summer 2015, we faced many Loxosceles rufescens cases of bites having led to extensive integumental necrosis whose features and singular evolution seems important to report. MATERIAL AND METHODS: We report the cases of nine patients who experienced a spider bite in the summer of 2015 in the Languedoc Roussillon...
September 27, 2016: Annales de Chirurgie Plastique et Esthétique
Mario Pezzi, Anna Maria Giglio, Annamaria Scozzafava, Orazio Filippelli, Giuseppe Serafino, Mario Verre
The spider bites are quite frequent and often resolve quickly without leaving outcomes; only some species are capable of causing necrotic and systematic lesions in humans. Among them, we should mention the genus Loxosceles. The venom released from the spider bite of Loxosceles species is composed of proteins, enzymes, and nonenzymatic polypeptides. The phospholipase D family was identified as the active component of the venom. This family of enzymes is responsible for the local and systemic effects observed in loxoscelism...
2016: Case Reports in Emergency Medicine
Laura de Mattos Milman, Giana Paula Müller, Paulo Ricardo Martins Souza, Aline Barcellos Grill, Deise Louise Bohn Rhoden, Carlos Augusto Mello-da-Silva, Gerson Vettorato
Acute generalized exanthematous pustulosis (AGEP) is an acute febrile rash, usually induced by drugs, which recently has been linked to spider bite. We report a case of a male patient, 48 years old, with an erythematous rash accompanied by fever and small non-follicular pustules. He reported previous pain in the buttock with the onset of a necrotic plaque. The lesion was compatible with spider bite of the genus Loxosceles. According to the EuroSCAR group instrument, the patient scored +10 indicating definite diagnosis of AGEP...
July 2016: Anais Brasileiros de Dermatologia
Daniele Chaves-Moreira, Fábio Moraes, Icaro Caruso, Olga Meiri Chaim, Andrea Senff-Ribeiro, Luciane Sussuchi, Jorge Chahine, Raghuvir Arni, Silvio Sanches Veiga
Loxoscelism refers to the clinical symptoms that develop after the brown spider bite. Brown spider venoms contain several phospholipase-D isoforms, which are the main toxins responsible for both the cutaneous and systemic effects of loxoscelism. Understanding of the phospholipase-D catalytic mechanism is crucial for the development of specific treatment that could reverse the toxic effects caused by the spider bite. Herein, based on enzymatic, biological, structural, and thermodynamic tests, we show some features suitable for designing drugs against loxoscelism...
August 26, 2016: Journal of Cellular Biochemistry
Arthur Estanislau Dantas, A O Carmo, Carolina Campolina Rebello Horta, Hortênsia Gomes Leal, Bárbara Bruna Ribeiro Oliveira-Mendes, Ana Paula Vimieiro Martins, Carlos Chávez-Olórtegui, Evanguedes Kalapothakis
Envenoming resulting from Loxosceles spider bites (loxoscelism) is a recognized public health problem in Brazil. However, the pathophysiology of loxoscelism caused by L. similis bites, which is widespread in Brazil, remains poorly understood. In the present work, the RNA sequencing (RNA-Seq - Next Generation sequencing - NGS) of the L. similis venom gland was performed to identify and analyze the sequences of the key component phospholipase D. The sequences were aligned based on their classical domains, and a phylogenetic tree was constructed...
September 15, 2016: Toxicon: Official Journal of the International Society on Toxinology
Gabriel Otto Meissner, Pedro Túlio de Resende Lara, Luis Paulo Barbour Scott, Antônio Sérgio Kimus Braz, Daniele Chaves-Moreira, Fernando Hitomi Matsubara, Eduardo Mendonça Soares, Dilza Trevisan-Silva, Luiza Helena Gremski, Silvio Sanches Veiga, Olga Meiri Chaim
Inhibitor cystine knots (ICKs) are a family of structural peptides with a large number of cysteine residues that form intramolecular disulfide bonds, resulting in a knot. These peptides are involved in a variety of biological functions including predation and defense, and are found in various species, such as spiders, scorpions, sea anemones, and plants. The Loxosceles intermedia venom gland transcriptome identified five groups of ICK peptides that represent more than 50 % of toxin-coding transcripts. Here, we describe the molecular cloning of U2-Sicaritoxin-Lit2 (U2-SCRTX-Lit2), bioinformatic characterization, structure prediction, and molecular dynamic analysis...
September 2016: Journal of Molecular Modeling
Monique Cachia, Liam Mercieca, Charles Mallia Azzopardi, Michael J Boffa
Spider poisoning is rare in Europe, with very few reported cases in the literature. Recluse spider (genus Loxosceles) bites may lead to cutaneous and systemic manifestations known as loxoscelism. We report the second known case of spider bite poisoning in Malta caused by Loxosceles rufescens (Mediterranean recluse spider). A young adult female presented with localised erythema and pain on her left thigh after a witnessed spider bite. Over a few days, the area developed features of dermonecrosis together with systemic symptoms, including fever, fatigue and a generalised erythematous eruption...
2016: BMJ Case Reports
M Canals, A Taucare-Rios, A D Brescovit, F Peña-Gomez, G Bizama, A Canals, L Moreno, R Bustamante
In Chile, all necrotic arachnidism is attributed to the Chilean recluse spider Loxosceles laeta (Nicolet) (Araneae: Sicariidae). It is predated by the spitting spider Scytodes globula (Nicolet) (Araneae: Scytodidae). The biology of each of these species is not well known and it is important to clarify their distributions. The aims of this study are to elucidate the variables involved in the niches of both species based on environmental and human footprint variables, and to construct geographic maps that will be useful in estimating potential distributions and in defining a map of estimated risk for loxoscelism in Chile...
July 18, 2016: Medical and Veterinary Entomology
Mauricio Canals, Lucila Moreno, Rigoberto Solís
It has been reported that Scytodes spiders are predators of spiders of the genus Loxosceles, but the question of the effect of Scytodes globula Nicolet on Loxosceles laeta (Nicolet) populations is still unanswered. The goal of this study is to analyze the population effect of S. globula on the population dynamics of L. laeta by means of simulation with projection matrices, considering the seasonal fluctuation of fecundity, random meetings between the predator and the prey, and limited growth of the L. laeta population...
August 2016: Environmental Entomology
Adriano M Morgon, Matheus R Belisario-Ferrari, Dilza Trevisan-Silva, Gabriel O Meissner, Larissa Vuitika, Brenda Marin, Alexandre K Tashima, Luiza H Gremski, Waldemiro Gremski, Andrea Senff-Ribeiro, Silvio S Veiga, Olga M Chaim
Loxosceles spiders' venom comprises a complex mixture of biologically active toxins, mostly consisting of low molecular mass components (2-40 kDa). Amongst, isoforms of astacin-like metalloproteases were identified through transcriptome and proteome analyses. Only LALP1 (Loxosceles Astacin-Like protease 1) has been characterized. Herein, we characterized LALP3 as a novel recombinant astacin-like metalloprotease isoform from Loxosceles intermedia venom. LALP3 cDNA was cloned in pET-SUMO vector, and its soluble heterologous expression was performed using a SUMO tag added to LALP3 to achieve solubility in Escherichia coli SHuffle T7 Express LysY cells, which express the disulfide bond isomerase DsbC...
September 2016: Biochimie
Camila Franco Batista Oliveira, Andrea Vilela, Luis Augusto M Coura, Fernandes Tenório Gomes Rodrigues, Ronaldo Alves Pinto Nagem, Carlos Chávez-Olortegui, Tatiani U Maioli, Liza F Felicori
In the present investigation we used a recombinant LiD1 toxin, named rLiD1his, from Loxosceles intermedia brown spider to elicit specific antibodies in mice carrying different Human Leukocyte Antigens class II (HLAII) {DRB1.0401 (DR4), DQB1.0601 (DQ6) and DQB1.0302 (DQ8)} as well as in BALB/C and C57BL/6 control mice. All mice strains produced high antibody titers against rLiD1his but DR4 mice antibodies (the lower responder mice) were not able to recognize L. intermedia crude venom. The anti-rLiD1his sera, except from DR4 mice, were able to neutralize dermonecrotic, hemorrhagic and edematogenic effects of rLiD1his in naïve rabbits...
July 19, 2016: Vaccine
D T Myamoto, G Pidde-Queiroz, A Pedroso, R M Gonçalves-de-Andrade, C W van den Berg, D V Tambourgi
A transcriptome analysis of the venom glands of the spider Loxosceles laeta, performed by our group, in a previous study (Fernandes-Pedrosa et al., 2008), revealed a transcript with a sequence similar to the human complement component C3. Here we present the analysis of this transcript. cDNA fragments encoding the C3 homologue (Lox-C3) were amplified from total RNA isolated from the venom glands of L. laeta by RACE-PCR. Lox-C3 is a 5178 bps cDNA sequence encoding a 190kDa protein, with a domain configuration similar to human C3...
September 2016: Immunobiology
L Vuitika, D Chaves-Moreira, I Caruso, M A Lima, F H Matsubara, M T Murakami, H K Takahashi, M S Toledo, M A Coronado, H B Nader, A Senff-Ribeiro, O M Chaim, R K Arni, S S Veiga
Brown spider phospholipases D from Loxosceles venoms are among the most widely studied toxins since they induce dermonecrosis, triggering inflammatory responses, increase vascular permeability, cause hemolysis, and renal failure. The catalytic (H12 and H47) and metal-ion binding (E32 and D34) residues in Loxosceles intermedia phospholipase D (LiRecDT1) were mutated to understand their roles in the observed activities. All mutants were identified using whole venom serum antibodies and a specific antibody to wild-type LiRecDT1, they were also analyzed by circular dichroism (CD) and differential scanning calorimetry (DSC)...
September 2016: Biochimica et Biophysica Acta
Vanderson Souza Sampaio, André Alexandre Gomes, Iran Mendonça Silva, Jacqueline Sachett, Luiz Carlos Lima Ferreira, Sâmella Oliveira, Meritxell Sabidò, Hipócrates Chalkidis, Maria Graças Vale Barbosa Guerra, Jorge Luis Salinas, Fan Hui Wen, Marcus Vinícius Guimarães Lacerda, Wuelton Marcelo Monteiro
BACKGROUND: A better knowledge of the burden and risk factors associated with severity due to spider bites would lead to improved management with a reduction of sequelae usually seen for this neglected health problem, and would ensure proper use of antivenoms in remote localities in the Brazilian Amazon. The aim of this study was to analyze the profile of spider bites reported in the state of Amazonas in the Western Brazilian Amazon, and to investigate potential risk factors associated with severity of envenomation...
2016: PloS One
Mara A Corrêa, Cinthya K Okamoto, Rute M Gonçalves-de-Andrade, Carmen W van den Berg, Denise V Tambourgi
Envenomation by Loxosceles spider is characterized by the development of dermonecrosis. In previous studies, we have demonstrated that increased expression/secretion of matrix metalloproteinases 2 and 9, induced by Loxosceles intermedia venom Class 2 SMases D (the main toxin in the spider venom), contribute to the development of cutaneous loxoscelism. In the present study we show that the more potent venom containing the Class 1 SMase D from Loxosceles laeta, in addition to increasing the expression/secretion of MMP2 and MMP9, also stimulates the expression of MMP7 (Matrilysin-1), which was associated with keratinocyte cell death...
2016: PloS One
Isabella Jiacomini, Sabrina K Silva, Nicolas Aubrey, Julien Muzard, Carlos Chavez-Olortegui, Juliana De Moura, Philippe Billiald, Larissa M Alvarenga
Bites by spiders from Loxosceles genus often lead to a wide variance in envenomation profile of patients and diagnosis is difficult due to the number of diseases that mimic loxoscelism. In such a context, it is of interest to consider the design of standardized recombinant colorimetric antibodies for diagnosis and specific detection of individual circulating toxins in biological fluids of envenomed patients. We have previously prepared a monoclonal murine IgG (LiMab7) that reacts with Loxosceles intermedia venom components of 32-35kDa and neutralizes the dermonecrotic activity of the venom...
May 2016: Immunology Letters
Aurélio Pedroso, Sergio Russo Matioli, Mario Tyago Murakami, Giselle Pidde-Queiroz, Denise V Tambourgi
BACKGROUND: Sphingomyelinase D is the main toxin present in the venom of Loxosceles spiders. Several isoforms present in these venoms can be structurally classified in two groups. Class I Sphingomyelinase D contains a single disulphide bridge and variable loop. Class II Sphingomyelinase D presents an additional intrachain disulphide bridge that links a flexible loop with a catalytic loop. These classes exhibit differences in their toxic potential. In this paper we address the distribution of the structural classes of SMase D within and among species of spiders and also their evolutionary origin by means of phylogenetic analyses...
2015: BMC Evolutionary Biology
Franklyn Cala-Riquelme, Miguel A Gutiérrez-Estrada, Eduardo Flórez Daza
No abstract text is available yet for this article.
2015: Zootaxa
Ma Ascensión Navarro Caballero
Loxocelism is a toxic condition produces by the venom inoculated by the bit of the recluse spider (genus Loxosceles). In can appear in two clinical forms: cutaneous loxocelism and viscerocutaneous Ioxocelim. The species Loxoceles rufescens, found in Spain, is responsible of cases of cutaneous loxocelism. Cutaneous loxocelism starts with an itch, later giving rise to intense pain, and it later takes either a more or less severe necrotic form or an edematous form. The latter, with a better prognosis, is the one we focus on here...
May 2015: Revista de Enfermería
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