Evaluation of mesenchymal cells and dapsone for the treatment of dermonecrotic wounds caused by Loxosceles laeta venom in rabbits / Avaliação de células mesenquimais e dapsona para o tratamento de feridas dermonecróticas causadas pelo veneno de Loxosceles laeta em coelhos

This study aimed to evaluate the efficacy of mesenchymal stem cells (MSC), alone or associated with dapsone (DAP), in treating dermonecrotic wounds caused by Loxosceles laeta venom. Twenty-five male rabbits were distributed into five groups. Negative control received ultrapure water (C-), whilst all other groups were injected with 20 μg of L. laeta venom. After 4 hours, each group received one of the following treatments: PBS (C+), DAP, MSC, and DAP+MSC. Animals were evaluated daily and photographic records made for analysis of wound area. Twelve days after, animals were euthanized and skin samples removed for histological analysis. We observed that DAP showed the best percentage of wound contraction at day 3. In the treatments using MSCs, a negative value of wound contraction was observed for the isolated MSCs, as well as a lower contraction value for the association of the MSC + DAP when compared to PBS, probably, by the increase in initial infammation after the application of stem cells, due to the fact that MSCs secrete a broad spectrum of bioactive molecules such as cytokines and growth factors that favor regeneration. Histologically, it was observed that animals of C+ showed extensive areas of necrosis, ulcers, neutrophilic infiltrate, and mineralization. Collagen deposition showed increase in MSC+DAP treatment, however vascularization remained unchanged. This is the first report using MSC and MSC+DAP as a treatment for cutaneous loxoscelism and more studies are needed to determine its use as an alternative therapy for dermonecrotic lesions caused by Loxosceles spider.

Este estudo teve como objetivo avaliar a eficácia das células-tronco mesenquimais (CTMs), isoladas ou associadas à dapsona (DAP), no tratamento de feridas dermonecróticas causadas pelo veneno de Loxosceles laeta. Vinte e cinco coelhos machos foram distribuídos em cinco grupos. O controle negativo recebeu água ultrapura (C-), enquanto todos os outros grupos foram injetados com 20 μg de veneno de L. laeta. Após 4 horas, cada grupo recebeu um dos seguintes tratamentos: PBS (C+), DAP, CTMs e DAP + CTMs. Os animais foram avaliados diariamente durante 12 dias, e feitos registros fotográficos para análise da ferida e no 12º dia, foram eutanasiados e, retiradas amostras de pele para análise histológica. Observou-se que a DAP apresentou o melhor percentual de contração da ferida no terceiro dia. Nos tratamentos com CTMs, observou-se uma contração negativa da ferida tanto para as CTMs isoladas, bem como a associação CTMs + DAP em relação ao PBS, possivelmente, pelo aumento da infamação inicial após a aplicação de células-tronco. Isso é devido ao fato de que as CTMs secretam um amplo espectro de moléculas bioativas como citocinas e fatores de crescimento que favorecem a regeneração. Histologicamente, observou-se que os animais de C+ apresentaram extensas áreas de necrose, úlceras, infiltrado neutrofílico, além de mineralização. Houve aumento de deposição de colágeno no tratamento CTMs + DAP, no entanto, a vascularização permaneceu inalterada. Este é o primeiro relato usando CTMs e CTMs + DAP como tratamento para loxoscelismo cutâneo e mais estudos são necessários para determinar seu uso como terapia alternativa para lesões demonecróticas causadas pela aranha Loxosceles.

Brown spider venom toxins: what are the functions of astacins, serine proteases, hyaluronidases, allergens, TCTP, serpins and knottins?

Accidents caused by the bites of brown spiders (Loxosceles) generate a clinical condition that often includes a threatening necrotic skin lesion near the bite site along with a remarkable inflammatory response. Systemic disorders such as hemolysis, thrombocytopenia, and acute renal failure may occur, but are much less frequent than the local damage. It is already known that phospholipases D, highly expressed toxins in Loxosceles venom, can induce most of these injuries. However, this spider venom has a great range of toxins that probably act synergistically to enhance toxicity. The other protein classes remain poorly explored due to the difficulty in obtaining sufficient amounts of them for a thorough investigation. They include astacins (metalloproteases), serine proteases, knottins, translationally controlled tumor proteins (TCTP), hyaluronidases, allergens and serpins. It has already been shown that some of them, according to their characteristics, may participate to some extent in the development of loxoscelism. In addition, all of these toxins present potential application in several areas. The present review article summarizes information regarding some functional aspects of the protein classes listed above, discusses the directions that could be taken to materialize a comprehensive investigation on each of these toxins as well as highlights the importance of exploring the full venom repertoire.(AU)

Brown spider venom toxins: what are the functions of astacins, serine proteases, hyaluronidases, allergens, TCTP, serpins and knottins?

Accidents caused by the bites of brown spiders (Loxosceles) generate a clinical condition that often includes a threatening necrotic skin lesion near the bite site along with a remarkable inflammatory response. Systemic disorders such as hemolysis, thrombocytopenia, and acute renal failure may occur, but are much less frequent than the local damage. It is already known that phospholipases D, highly expressed toxins in Loxosceles venom, can induce most of these injuries. However, this spider venom has a great range of toxins that probably act synergistically to enhance toxicity. The other protein classes remain poorly explored due to the difficulty in obtaining sufficient amounts of them for a thorough investigation. They include astacins (metalloproteases), serine proteases, knottins, translationally controlled tumor proteins (TCTP), hyaluronidases, allergens and serpins. It has already been shown that some of them, according to their characteristics, may participate to some extent in the development of loxoscelism. In addition, all of these toxins present potential application in several areas. The present review article summarizes information regarding some functional aspects of the protein classes listed above, discusses the directions that could be taken to materialize a comprehensive investigation on each of these toxins as well as highlights the importance of exploring the full venom repertoire.(AU)

Heterophilic antibodies in sera from individuals without loxoscelism cross-react with phospholipase D from the venom of Loxosceles and Sicarius spiders

Background Loxoscelism is a severe human envenomation caused by Loxosceles spider venom. To the best of our knowledge, no study has evaluated the presence of antibodies against Loxosceles venom in loxoscelism patients without treatment with antivenom immunotherapy. We perform a comparative analysis for the presence of antibodies capable of recognizing Loxosceles venom in a group of patients diagnosed with loxoscelism and in a group of people without loxoscelism. Methods The detection of L. laeta venom, Sicarius venom and recombinant phospholipases D from Loxosceles (PLDs) in sera from people with loxoscelism (Group 1) and from healthy people with no history of loxoscelism (Group 2) was evaluated using immuno-dot blot, indirect ELISA, and Western blot. Results We found naturally heterophilic antibodies (IgG-type) in people without contact with Loxosceles spiders or any clinical history of loxoscelism. Either serum pools or single sera from Group 1 and Group 2 analyzed by dot blot tested positive for L. laeta venom. Indirect ELISA for venom recognition showed titles of 1:320 for Group 1 sera and 1:160 for Group 2 sera. Total IgG quantification showed no difference in sera from both groups. Pooled sera and purified IgG from sera of both groups revealed venom proteins between 25 and 32 kDa and the recombinant phospholipase D isoform 1 (rLlPLD1), specifically. Moreover, heterophile antibodies cross-react with PLDs from other Loxosceles species and the venom of Sicarius spider. Conclusions People without contact with the spider venom produced heterophilic antibodies capable of generating a cross-reaction against the venom of L. laeta and Sicarius spiders. Their presence and possible interference should be considered in the development of immunoassays for Loxosceles venom detection.(AU)

Heterophilic antibodies in sera from individuals without loxoscelism cross-react with phospholipase D from the venom of Loxosceles and Sicarius spiders

Background Loxoscelism is a severe human envenomation caused by Loxosceles spider venom. To the best of our knowledge, no study has evaluated the presence of antibodies against Loxosceles venom in loxoscelism patients without treatment with antivenom immunotherapy. We perform a comparative analysis for the presence of antibodies capable of recognizing Loxosceles venom in a group of patients diagnosed with loxoscelism and in a group of people without loxoscelism. Methods The detection of L. laeta venom, Sicarius venom and recombinant phospholipases D from Loxosceles (PLDs) in sera from people with loxoscelism (Group 1) and from healthy people with no history of loxoscelism (Group 2) was evaluated using immuno-dot blot, indirect ELISA, and Western blot. Results We found naturally heterophilic antibodies (IgG-type) in people without contact with Loxosceles spiders or any clinical history of loxoscelism. Either serum pools or single sera from Group 1 and Group 2 analyzed by dot blot tested positive for L. laeta venom. Indirect ELISA for venom recognition showed titles of 1:320 for Group 1 sera and 1:160 for Group 2 sera. Total IgG quantification showed no difference in sera from both groups. Pooled sera and purified IgG from sera of both groups revealed venom proteins between 25 and 32 kDa and the recombinant phospholipase D isoform 1 (rLlPLD1), specifically. Moreover, heterophile antibodies cross-react with PLDs from other Loxosceles species and the venom of Sicarius spider. Conclusions People without contact with the spider venom produced heterophilic antibodies capable of generating a cross-reaction against the venom of L. laeta and Sicarius spiders. Their presence and possible interference should be considered in the development of immunoassays for Loxosceles venom detection.

Highlights in the knowledge of brown spider toxins

Abstract Brown spiders are venomous arthropods that use their venom for predation and defense. In humans, bites of these animals provoke injuries including dermonecrosis with gravitational spread of lesions, hematological abnormalities and impaired renal function. The signs and symptoms observed following a brown spider bite are called loxoscelism. Brown spider venom is a complex mixture of toxins enriched in low molecular mass proteins (440 kDa). Characterization of the venom confirmed the presence of three highly expressed protein classes: phospholipases D, metalloproteases (astacins) and insecticidal peptides (knottins). Recently, toxins with low levels of expression have also been found in Loxosceles venom, such as serine proteases, protease inhibitors (serpins), hyaluronidases, allergen-like toxins and histamine-releasing factors. The toxin belonging to the phospholipase-D family (also known as the dermonecrotic toxin) is the most studied class of brown spider toxins. This class of toxins single-handedly can induce inflammatory response, dermonecrosis, hemolysis, thrombocytopenia and renal failure. The functional role of the hyaluronidase toxin as a spreading factor in loxoscelism has also been demonstrated. However, the biological characterization of other toxins remains unclear and the mechanism by which Loxosceles toxins exert their noxious effects is yet to be fully elucidated. The aim of this review is to provide an insight into brown spider venom toxins and toxicology, including a description of historical data already available in the literature. In this review article, the identification processes of novel Loxosceles toxins by molecular biology and proteomic approaches, their biological characterization and structural description based on x-ray crystallography and putative biotechnological uses are described along with the future perspectives in this field.

Highlights in the knowledge of brown spider toxins

Abstract Brown spiders are venomous arthropods that use their venom for predation and defense. In humans, bites of these animals provoke injuries including dermonecrosis with gravitational spread of lesions, hematological abnormalities and impaired renal function. The signs and symptoms observed following a brown spider bite are called loxoscelism. Brown spider venom is a complex mixture of toxins enriched in low molecular mass proteins (4-40 kDa). Characterization of the venom confirmed the presence of three highly expressed protein classes: phospholipases D, metalloproteases (astacins) and insecticidal peptides (knottins). Recently, toxins with low levels of expression have also been found in Loxosceles venom, such as serine proteases, protease inhibitors (serpins), hyaluronidases, allergen-like toxins and histamine-releasing factors. The toxin belonging to the phospholipase-D family (also known as the dermonecrotic toxin) is the most studied class of brown spider toxins. This class of toxins single-handedly can induce inflammatory response, dermonecrosis, hemolysis, thrombocytopenia and renal failure. The functional role of the hyaluronidase toxin as a spreading factor in loxoscelism has also been demonstrated. However, the biological characterization of other toxins remains unclear and the mechanism by which Loxosceles toxins exert their noxious effects is yet to be fully elucidated. The aim of this review is to provide an insight into brown spider venom toxins and toxicology, including a description of historical data already available in the literature. In this review article, the identification processes of novel Loxosceles toxins by molecular biology and proteomic approaches, their biological characterization and structural description based on x-ray crystallography and putative biotechnological uses are described along with the future perspectives in this field.(AU)

Highlights in the knowledge of brown spider toxins

Brown spiders are venomous arthropods that use their venom for predation and defense. In humans, bites of these animals provoke injuries including dermonecrosis with gravitational spread of lesions, hematological abnormalities and impaired renal function. The signs and symptoms observed following a brown spider bite are called loxoscelism. Brown spider venom is a complex mixture of toxins enriched in low molecular mass proteins (4-40 kDa). Characterization of the venom confirmed the presence of three highly expressed protein classes: phospholipases D, metalloproteases (astacins) and insecticidal peptides (knottins). Recently, toxins with low levels of expression have also been found in Loxosceles venom, such as serine proteases, protease inhibitors (serpins), hyaluronidases, allergen-like toxins and histamine-releasing factors. The toxin belonging to the phospholipase-D family (also known as the dermonecrotic toxin) is the most studied class of brown spider toxins. This class of toxins single-handedly can induce inflammatory response, dermonecrosis, hemolysis, thrombocytopenia and renal failure. The functional role of the hyaluronidase toxin as a spreading factor in loxoscelism has also been demonstrated. However, the biological characterization of other toxins remains unclear and the mechanism by which Loxosceles toxins exert their noxious effects is yet to be fully elucidated. The aim of this review is to provide an insight into brown spider venom toxins and toxicology, including a description of historical data already available in the literature. In this review article, the identification processes of novel Loxosceles toxins by molecular biology and proteomic approaches, their biological characterization and structural description based on x-ray crystallography and putative biotechnological uses are described along with the future perspectives in this field.(AU)

Long time not seen: Expanding the records of Loxosceles amazonica (Araneae: Sicariidae) in the Amazonas state, Brazil / Muito tempo sem ver: Expansão dos registros de Loxosceles amazonica (Araneae: Sicariidae) para o estado do Amazonas, Brasil

Spiders of the genus Loxosceles, commonly known as brown recluse spiders, can cause serious accidents in humans. Their venom has a powerful proteolytic and hemolytic action. Each year these spiders are the cause of a great number of araneism in Brazil. This work presents new records of Loxosceles amazonica for the municipal districts of Manaus and Iranduba, Amazonas, Brazil.(AU)

As aranhas do gênero Loxosceles, conhecidas como aranhas marrons, podem causar sérios acidentes em humanos. O veneno destas aranhas possui potente ação proteolítica e hemolítica. A cada ano estas aranhas são responsáveis pelo maior número de araneísmos no Brasil. Este trabalho apresenta novos registros de Loxosceles amazonica para o estado do Amazonas, Brasil.(AU)

Long time not seen: Expanding the records of Loxosceles amazonica (Araneae: Sicariidae) in the Amazonas state, Brazil / Muito tempo sem ver: Expansão dos registros de Loxosceles amazonica (Araneae: Sicariidae) para o estado do Amazonas, Brasil

Spiders of the genus Loxosceles, commonly known as brown recluse spiders, can cause serious accidents in humans. Their venom has a powerful proteolytic and hemolytic action. Each year these spiders are the cause of a great number of araneism in Brazil. This work presents new records of Loxosceles amazonica for the municipal districts of Manaus and Iranduba, Amazonas, Brazil.

As aranhas do gênero Loxosceles, conhecidas como aranhas marrons, podem causar sérios acidentes em humanos. O veneno destas aranhas possui potente ação proteolítica e hemolítica. A cada ano estas aranhas são responsáveis pelo maior número de araneísmos no Brasil. Este trabalho apresenta novos registros de Loxosceles amazonica para o estado do Amazonas, Brasil.

Secretoma no tratamento de lesão dermonecrótica induzida pelo veneno de Loxosceles intermedia

Objetivou-se avaliar os efeitos do secretoma, em feridas dermonecróticas em coelhos submetidos à injeção de veneno de Loxosceles intermedia. Foram utilizados 16 coelhos machos, adultos, Nova Zelândia, com peso médio de 2,0 kg, distribuídos em quatro grupos (n=4). À exceção do grupo controle (grupo I), que foi submetido apenas à aplicação de secretoma (60g de secretoma diluído em tampão fosfato-salina a 0,5%), todos os outros grupos foram submetidos à administração de 10g de veneno de Loxosceles intermedia, diluído em NaCl 0,9%, via intradérmica (ID) na região interescapular e, tratados 30 minutos após a injeção do veneno, da seguinte forma: grupo II (NaCl 0,9%, via ID); grupo III (60g de secretoma diluído em tampão fosfato-salina 0,5%, via ID) e, grupo IV (60g de secretoma diluído em tampão fosfato-salina 0,5% via endovenosa - EV). Os animais foram avaliados diariamente e realizados registros fotográficos em altura pré-definida de 30 cm para posterior análise da evolução da área da ferida por morfometria. Amostras de sangue foram coletadas imediatamente antes da aplicação do veneno (tempo 0) e 3, 9 e 15 dias após, para avaliação e monitoração de parâmetros hematológicos e bioquímicos séricos e plasmáticos. Após 15 dias os animais foram eutanasiados, submetidos a necropsia e amostras de pele ao redor da lesão foram coletadas para posterior análise histológica. Os resultados demonstraram que os animais do GI não apresentaram edema, eritema, halo ou necrose. No primeiro dia da injeção do veneno, após tratamentos com secretoma, os animais do GIII e GIV, apresentaram maior grau de edema, quando comparado aos animais do GII. Todavia, no 15ª dia de avaliação, o edema foi menor nos animais do GIII e GIV e, de forma inversa, maior no GI. O eritema foi observado nos grupos que receberam veneno de L. intermedia (GII, GIII e GIV), e comparativamente, no primeiro dia, nos grupos II e III foram similares entre si, e diferentes do GIV que apresentou menor diâmetro de eritema (p<0,05). O halo hemorrágico não foi observado no GI e nos animais que receberam veneno (GII, GIII e GIV), nos tempos 1 e 3, não houve diferença (p>0,05). Deve ser salientado que, no nono dia, somente nos animais do GIV, ainda havia halo hemorrágico. Todavia, macroscopicamente, no GIV, apenas um animal apresentou evolução para ferida dermonecrótica. Na avaliação microscópica, não foram observadas alterações na pele dos animais do GI, entretanto, apesar de todos animais que foram desafiados com o veneno, apresentarem alterações muito semelhantes, como necrose e infiltração heterofílica, no GIV, os animais apresentaram ativação fibroblástica, desenvolvimento precoce de tecido conjuntivo, neovascularização e reepitelização tecidual, conferindo alternativa comprovadamente eficaz em relação ao processo de cicatrização. Em relação a hematologia não houve alteração digna de nota e na bioquímica sérica, somente houve aumento na concentração de CK no tempo 3, nos grupos GIII e GIV e, posterior redução a partir do nono dia. Esses mesmos grupos também apresentaram aumento de LDH e ureia, porém os valores permaneceram dentro dos parâmetros fisiológicos para a espécie leporina. Conclui-se que a terapia com o secretoma pode ser utilizada na cicatrização da ferida dermonecrótica no loxoscelismo.

The objective was to evaluate the effects of the secretome, in dermonecrotic wounds in rabbits subjected to injection of Loxosceles intermedia. Sixteen male, adult, New Zealand rabbits, with a mean weight of 2.0 kg, were distributed in four groups (n=4). Except for the control group (group I), which was subjected only to the application of secretome (60g of secretome diluted in 0.5% phosphate-saline buffer), all other groups were subjected to the administration of 10g of L. intermedia venom, diluted in 0.9% NaCl, via intradermal (ID) in the interscapular region and, treated 30 minutes after the venom injection, as follows: group II (NaCl 0.9%, via ID); Group III (60g of secretome diluted in 0.5% phosphate-saline buffer, via ID) and, group IV (60g of secretome diluted in 0.5% phosphate-saline buffer intravenous - IV). Animals were evaluated daily and photographic records were taken at a predefined height of 30 cm for later analysis of the evolution of the wound area by morphometry. Blood samples were collected immediately before venom application (time 0) and 3, 9 and 15 days after, for evaluation and monitoring of hematological and serum and plasma biochemical parameters. After 15 days, the animals were euthanized, submitted to necropsy, and skin samples around the lesion were collected for subsequent histological analysis. The results showed that the animals in GI did not have edema, erythema, hemorrhagic halo or necrosis. On the first day of venom injection, after secretome treatments, the animals in GIII and GIV showed a more significant degree of edema, when compared to the animals in GII. However, on the 15th day of evaluation, the edema was lower in the animals of GIII and GIV, and conversely, higher in GI. Erythema was observed in the groups that received L. intermedia venom (GII, GIII and GIV), and comparatively, on day 1st, groups II and III were similar to each other, and different from GIV which showed smaller erythema diameter (p<0.05). The hemorrhagic halo was not observed in GI and in the animals that received venom (GII, GIII, and GIV), at times 1 and 3, there was no difference (p>0.05). It should be noted that on the 9th day, only in the animals of GIV, there was still a hemorrhagic halo. However, macroscopically, in GIV, only one animal showed evolution to a dermonecrotic wound. In the microscopic evaluation, no changes were observed in the skin of animals of GI, however, although all animals that were challenged with the venom presented very similar changes, such as necrosis and heterophilic infiltration, in GIV, the animals showed fibroblastic activation, early development of connective tissue, neovascularization, and tissue reepithelialization, conferring a proven effective alternative in relation to the healing process. Regarding hematology, there was no noteworthy change, and in biochemistry serum profile, there was only an increase in CK concentration at time 3, in groups GIII and GIV, and a subsequent reduction from day 9. These same groups also showed an increase in LDH and urea, but the values remained within the physiological parameters for the leporine species. It is concluded that secretome therapy can be used in dermonecrotic wound healing in loxoscelism.

Histopathological characterization of experimentally induced cutaneous loxoscelism in rabbits inoculated with Loxosceles similis venom

Envenomation by Loxosceles bites is characterized by dermonecrotic and/or systemic features that lead to several clinical signs and symptoms called loxoscelism. Dermonecrotic lesions are preceded by thrombosis of the dermal plexus. Recent studies show that atheromatous plaque is prone to thrombosis due to endothelial cell apoptosis. To the best of our knowledge, there are no reports of microscopic dermal lesion and endothelial cell apoptosis induced by Loxosceles similis venom in the literature. Thus, the aim of the present study is to describe histological lesions induced by L. similis venom in rabbit skin and to elucidate whether apoptosis of endothelial cells is involved in the pathogenesis of loxoscelism. Forty male rabbits were split into two groups: the control group (intradermally injected with 50 µL of PBS) and the experimental group (intradermally injected with 0.5 µg of L. similis crude venom diluted in 50 µL of PBS). After 2, 4, 6 and 8 hours of injection, skin fragments were collected and processed for paraffin or methacrylate embedding. Sections of 5 µm thick were stained by HE, PAS or submitted to TUNEL reaction. Microscopically, severe edema, diffuse heterophilic inflammatory infiltrate, perivascular heterophilic infiltrate, thrombosis, fibrinoid necrosis of arteriolar wall and cutaneous muscle necrosis were observed. Two hours after venom injection, endothelial cells with apoptosis morphology were evidenced in the dermal plexus. Apoptosis was confirmed by TUNEL reaction. It seems that endothelial cell apoptosis and its consequent desquamation is an important factor that induces thrombosis and culminates in dermonecrosis, which is characteristic of cutaneous loxoscelism.(AU)

Loxoscelismo cutâneo-visceral em cão na cidade de Belo Horizonte, MG – relato de caso / Cutaneous and visceral loxoscelism in a dog in Belo Horizonte (MG) – case report / Loxoscelismo cutáneo-visceral en un perro de la ciudad de Belo Horizonte – reporte de caso

O loxoscelismo é uma síndrome clínica ocasionada pela picada da aranha-marrom, Loxosceles sp, que vem ganhando importância na medicina humana e veterinária devido ao aumento do número de casos. Ela ocasiona na maioria das vezes uma ferida dermonecrótica de difícil cicatrização e, com menor frequência, alterações sistêmicas que podem levar o paciente ao óbito. O diagnóstico é presuntivo, já que não existem testes diagnósticos comerciais disponíveis. O tratamento é controverso e deve ser iniciado de forma precoce, com uma abordagem emergencial, a fim de monitorar parâmetros clínicos para identificar alterações sistêmicas e evitar a evolução da doença. Este trabalho tem como objetivo relatar o caso de um cão atendido na região de Belo Horizonte, diagnosticado com loxoscelismo cutâneo-visceral.

Loxoscelism is a clinical syndrome caused by the bite of Loxosceles sp spiders, which is attaining increasing importance in human and veterinary medicine due to the increased number of cases. Most of the time it causes a hard-to-heal dermonecrotic wound and, less frequently, systemic changes that may lead to death. Diagnosis is generally based on history and clinical signs, since there are no available commercial diagnostic tests. Treatment is controversial and should be initiated early and with an emergency approach, in order to monitor clinical parameters to identify and avoid systemic changes. This study aims to report the case of an animal diagnosed with cutaneous-visceral loxoscelism in Belo Horizonte.

El loxoscelismo es un síndrome provocado por la picadura de la araña casera o violín, Loxosceles sp, que está cobrando cada vez más importancia en medicina humana y veterinaria, debido al aumento del número de casos. Su picadura ocasiona en la mayor parte de los casos una herida con necrosis dérmica de difícil cicatrización y, menos frecuentemente, alteraciones sistémicas que pueden provocar la muerte del paciente. El diagnóstico suele ser presuntivo, ya que no se dispone de tests diagnósticos comerciales. El tratamiento es controvertido y se debe iniciar precozmente ya que es una emergencia, con el fin de monitorear los parámetros clínicos que evidencien alteraciones sistémicas y evitar la evolución del cuadro. Este trabajo relata el caso de un perro atendido en la región de Belo Horizonte, que presentó un cuadro de loxoscelismo cutáneo visceral.

Loxoscelismo cutâneo-visceral em cão na cidade de Belo Horizonte, MG relato de caso / Cutaneous and visceral loxoscelism in a dog in Belo Horizonte (MG) case report / Loxoscelismo cutáneo-visceral en un perro de la ciudad de Belo Horizonte reporte de caso

O loxoscelismo é uma síndrome clínica ocasionada pela picada da aranha-marrom, Loxosceles sp, que vem ganhando importância na medicina humana e veterinária devido ao aumento do número de casos. Ela ocasiona na maioria das vezes uma ferida dermonecrótica de difícil cicatrização e, com menor frequência, alterações sistêmicas que podem levar o paciente ao óbito. O diagnóstico é presuntivo, já que não existem testes diagnósticos comerciais disponíveis. O tratamento é controverso e deve ser iniciado de forma precoce, com uma abordagem emergencial, a fim de monitorar parâmetros clínicos para identificar alterações sistêmicas e evitar a evolução da doença. Este trabalho tem como objetivo relatar o caso de um cão atendido na região de Belo Horizonte, diagnosticado com loxoscelismo cutâneo-visceral.(AU)

Loxoscelism is a clinical syndrome caused by the bite of Loxosceles sp spiders, which is attaining increasing importance in human and veterinary medicine due to the increased number of cases. Most of the time it causes a hard-to-heal dermonecrotic wound and, less frequently, systemic changes that may lead to death. Diagnosis is generally based on history and clinical signs, since there are no available commercial diagnostic tests. Treatment is controversial and should be initiated early and with an emergency approach, in order to monitor clinical parameters to identify and avoid systemic changes. This study aims to report the case of an animal diagnosed with cutaneous-visceral loxoscelism in Belo Horizonte.(AU)

El loxoscelismo es un síndrome provocado por la picadura de la araña casera o violín, Loxosceles sp, que está cobrando cada vez más importancia en medicina humana y veterinaria, debido al aumento del número de casos. Su picadura ocasiona en la mayor parte de los casos una herida con necrosis dérmica de difícil cicatrización y, menos frecuentemente, alteraciones sistémicas que pueden provocar la muerte del paciente. El diagnóstico suele ser presuntivo, ya que no se dispone de tests diagnósticos comerciales. El tratamiento es controvertido y se debe iniciar precozmente ya que es una emergencia, con el fin de monitorear los parámetros clínicos que evidencien alteraciones sistémicas y evitar la evolución del cuadro. Este trabajo relata el caso de un perro atendido en la región de Belo Horizonte, que presentó un cuadro de loxoscelismo cutáneo visceral.(AU)

Loxosceles spider bite in Turkey (Loxosceles rufescens, Sicariidae, Araneae)

Loxoscelism is caused by envenomation by spiders that belong to the Loxosceles genus. In loxoscelism, a local necrotic lesion appears and, in many cases, loxoscelism or necrotic araneism is considered a serious public health problem. There is no diagnostic test available to help the physician make a diagnostic or therapeutic decision. Here, we report the case of a severe dermonecrotic araneism (loxoscelism) in Turkey probably due to the bite of Loxosceles rufescens. There was little erythema at the beginning, followed by severe necrosis after 20 days, and skin grafting was needed although the case was treated.

Loxosceles spider bite in Turkey (Loxosceles rufescens, Sicariidae, Araneae)

Loxoscelism is caused by envenomation by spiders that belong to the Loxosceles genus. In loxoscelism, a local necrotic lesion appears and, in many cases, loxoscelism or necrotic araneism is considered a serious public health problem. There is no diagnostic test available to help the physician make a diagnostic or therapeutic decision. Here, we report the case of a severe dermonecrotic araneism (loxoscelism) in Turkey probably due to the bite of Loxosceles rufescens. There was little erythema at the beginning, followed by severe necrosis after 20 days, and skin grafting was needed although the case was treated.(AU)

Evaluation of the efficacy of vacuum cleaners for the integrated control of brown spider Loxosceles intermedia

Some venomous spiders of the genus Loxosceles can reach high population densities inside and around houses. In Brazil, most spider accidents are related to Loxosceles intermedia. Control of loxoscelism should utilize integrated pest management tools, such as vacuum cleaners, to eliminate egg sacs, webs and spiders. The present study tested the efficacy of one type of vacuum cleaner (for professional and domestic use) in the control of L. intermedia populations. Cockroaches (Pycnoscelus surinamensis) were used in some tests for comparison. Vacuuming using standard accessories or a paper tube resulted in the death of all female (n=60), male (n=60), young (n=60) and just-hatched (n=60) L. intermedia, and all egg sacs (n=5) were destroyed. The removal of the plastic plate present at the bottom of the vacuuming tube inside the machine allowed some spiders to survive the vacuuming process. When kept inside a vacuum bag full of dust and debris, adult females (n=10) survived for 10 days; however, significant mortality was observed among male (n=10) and young individuals (n=10). Addition of cornstarch to the vacuum bag did not affect the spiders (n=20). Vacuum cleaners, such as the one used in the present investigation, are promising tools for integrated management of L. intermedia and other spiders in domestic environments.

Evaluation of the efficacy of vacuum cleaners for the integrated control of brown spider Loxosceles intermedia

Some venomous spiders of the genus Loxosceles can reach high population densities inside and around houses. In Brazil, most spider accidents are related to Loxosceles intermedia. Control of loxoscelism should utilize integrated pest management tools, such as vacuum cleaners, to eliminate egg sacs, webs and spiders. The present study tested the efficacy of one type of vacuum cleaner (for professional and domestic use) in the control of L. intermedia populations. Cockroaches (Pycnoscelus surinamensis) were used in some tests for comparison. Vacuuming using standard accessories or a paper tube resulted in the death of all female (n=60), male (n=60), young (n=60) and just-hatched (n=60) L. intermedia, and all egg sacs (n=5) were destroyed. The removal of the plastic plate present at the bottom of the vacuuming tube inside the machine allowed some spiders to survive the vacuuming process. When kept inside a vacuum bag full of dust and debris, adult females (n=10) survived for 10 days; however, significant mortality was observed among male (n=10) and young individuals (n=10). Addition of cornstarch to the vacuum bag did not affect the spiders (n=20). Vacuum cleaners, such as the one used in the present investigation, are promising tools for integrated management of L. intermedia and other spiders in domestic environments.(AU)

Tropical House Gecko (Hemidactylus mabouia) predation on brown spiders (Loxosceles intermedia)

Brown spiders (Loxosceles spp.) are venomous arachnids, successfully adapted to urban habitats in Brazil. Loxoscelism became a serious public health problem in Paraná State, especially at the capital Curitiba, where the most abundant species is Loxosceles intermedia. Hemidactylus mabouia (Gekkonidae) lizards are synanthropic predators of arthropods. In this paper, we describe the predatory behavior of the Tropical House Gecko H. mabouia on L. intermedia under laboratory conditions. Twelve geckos were observed, and all of them fed on brown spiders (n=123 observations). The attack consisted of a fast run followed by one bite on the spiders abdomen or legs. The geckos did not attack L. intermedia anterior body parts, probably due to the fangs present in this region. Two Hemidactylus individuals were killed by L. intermedia bites: during a predatory encounter, and by an induced bite on a restrained lizard. The observations summarized in this paper show that H. mabouia could be used in the biological control of Loxosceles populations in human dwellings. However, additional field studies are necessary to quantify the impact of H. mabouia predation on urban populations of L. intermedia and other species of the same genus.