Discovery of broadly-neutralizing antibodies against brown recluse spider and Gadim scorpion sphingomyelinases using consensus toxins as antigens.

Broadly-neutralizing monoclonal antibodies are becoming increasingly important tools for treating infectious diseases and animal envenomings. However, designing and developing broadly-neutralizing antibodies can be cumbersome using traditional low-throughput iterative protein engineering methods. Here, we present a new high-throughput approach for the standardized discovery of broadly-neutralizing monoclonal antibodies relying on phage display technology and consensus antigens representing average sequences of related proteins. We showcase the utility of this approach by applying it to toxic sphingomyelinases from the venoms of species from very distant orders of the animal kingdom, the recluse spider and Gadim scorpion. First, we designed a consensus sphingomyelinase and performed three rounds of phage display selection, followed by DELFIA-based screening and ranking, and benchmarked this to a similar campaign involving cross-panning against recombinant versions of the native toxins. Second, we identified two scFvs that not only bind the consensus toxins, but which can also neutralize sphingomyelinase activity of native whole venom in vitro. Finally, we conclude that the phage display campaign involving the use of the consensus toxin was more successful in yielding cross-neutralizing scFvs than the phage display campaign involving cross-panning.

Aranhas de interesse médico no Brasil / Spiders of medical interest in Brazil

O documento apresenta informações sobre aranhas de importância médica no Brasil. Descreve a estrutura externa das aranhas e destaca três gêneros de importância em saúde pública: aranha-marrom (Loxosceles), aranha-armadeira ou macaca (Phoneutria) e viúva-negra (Latrodectus). Traz imagens dessas espécies e lista sinais, sintomas e tratamento para acidentes com elas. Apresenta dados de série histórica de acidentes por aranhas no Brasil e Tocantins entre 2000-2022. Por fim, traz recomendações sobre prevenção e primeiro atendimento para acidentes com aranhas.

The document provides information on medically significant spiders in Brazil. It describes the external structure of spiders and highlights three genera of public health importance: brown recluse spider (Loxosceles), wandering spider or macaque spider (Phoneutria), and black widow spider (Latrodectus). It includes images of these species and lists signs, symptoms, and treatment for accidents involving them. It presents historical data on spider-related accidents in Brazil and Tocantins between 2000-2022. Finally, it provides recommendations for prevention and initial first aid for spider bites.

El documento proporciona información sobre arañas de importancia médica en Brasil. Describe la estructura externa de las arañas y destaca tres géneros de importancia para la salud pública: la araña de rincón (Loxosceles), la araña errante o araña mono (Phoneutria) y la viuda negra (Latrodectus). Incluye imágenes de estas especies y enumera los signos, síntomas y tratamiento para accidentes con ellas. Presenta datos históricos sobre accidentes relacionados con arañas en Brasil y Tocantins entre 2000 y 2022. Por último, proporciona recomendaciones para la prevención y la atención de primeros auxilios en caso de picaduras de araña.

Massive dermal ulcerative lesions due to brown recluse spider bite: a rare case report and review of literature.

A brown recluse spider (BRS) bite is challenging to confirm, but may be clinically diagnosed by considering the location, the season of the year, and the clinical manifestations. Here, the case of a 26-year-old male who presented after an insect bite with a skin lesion, bruising, severe swelling, and diffuse blisters on the right lower extremity after three days, is described. Following clinical examination, patient history assessment, and consideration of other relevant factors, the patient received a differential diagnosis of necrotizing fasciitis caused by BRS bite. Although spider bite poisoning is rare, proper diagnosis and management are important because, in some cases, the outcomes may be devastating.

Severe complications in a 25-year-old male after brown recluse spider bite treated by therapeutic plasma exchange: A case report and review of other case studies.

Although in the majority of patients (90%), the bite wound of brown recluse spider resolves spontaneously, some patients may experience a severe reaction requiring hospitalization. A 25-year-old male developed severe hemolytic anemia, jaundice, and other complications following a brown recluse spider bite on his posterior right thigh. He was treated with methylprednisolone, antibiotics, and red blood cells (RBCs) transfusion without response. Therapeutic plasma exchange (TPE) was added to the treatment regimen, and his hemoglobin (Hb) was eventually stabilized, leading to significant clinical improvement. The beneficial effect of TPE in the current case was compared to three other reported cases. We recommend close monitoring of Hb levels in patients with systemic loxoscelism during the first week after brown recluse spider bite and early implementation of TPE in the management of severe acute hemolysis when patients do not respond to usual treatment modalities and RBC transfusion.

Brown recluse spider envenomation with systemic loxoscelism and delayed hemolysis: A case report.

The brown recluse spider (Loxosceles reclusa) is endemic to the South, West and Central Midwestern United States, and envenomation from this spider can cause cutaneous and/or systemic symptoms. We present a case of systemic loxocelism in an adolescent male resulting in three emergency department visits and two hospitalizations for a rare case of delayed hemolysis 6 days after envenomation. A 19-year-old male presented to the emergency department twice within two days after envenomation with worsening pain, subjective fever, chills, nausea and vomiting. He required a two-day hospitalization for rhabdomyolysis and acute kidney injury. The patient was discharged with improving symptoms and laboratory results on day four before returning again on day seven with worsening symptoms. He was diagnosed with hemolytic anemia on day seven and was subsequently hospitalized for six days. This case of systemic loxoscelism manifested hemolysis six days after envenomation, following an improvement in symptoms and laboratory studies. This case highlights the need for continuous monitoring and/or follow-up in cases of systemic loxocelism.

Acute necrotic arachnidism with necrotising fasciitis and recurrent pneumothorax.

A male infant presented with swelling of the left leg and fever. Over the next 2 days, the area developed fasciitis extending to the left thigh, abdomen, and lower chest. Meanwhile, the parents found a giant brown spider within the infant's cot belonging to the genus Loxosceles, otherwise called the brown recluse spider. The dermo-myonecrosis progressed to deeper tissues involving the lung parenchyma requiring invasive ventilation. CT of the thorax showed multiple pneumatoceles, and lung biopsy showed alveolar necrosis. The infant was treated with intravenous antibiotics and corticosteroids. We drained the pneumothoraces by thoracostomy and insertion of intercostal drainage tubes. The infant required respiratory support initially by conventional ventilation, which was escalated to high-frequency oscillatory ventilation. He had refractory hypoxaemia and died. This is the first fatal case of acute spider envenomation described in India. Spider envenomation must be considered in patients with sudden onset, rapidly progressive necrotising fasciitis unresponsive to antibiotic therapy.

Primer registro de un caso de loxoscelismo cutáneo ocasionado por mordedura de araña violinista (Loxosceles yucatana) en Yucatán, México / First record of a case of cutaneous loxoscelism caused by violin spider (Loxosceles yucatana) bite in Yucatan, Mexico

El loxoscelismo es ocasionado cuando el veneno dermonecrótico producido por las arañas del género Loxosceles, conocidas como «arañas violinistas», ingresa al organismo de una persona a través de su mordida. En México ocurre un subregistro de los casos de loxoscelismo por la ausencia de pruebas de laboratorio para su diagnóstico y la dificultad del cuadro clínico. El objetivo de este trabajo es describir un caso de loxoscelismo cutáneo ocasionado por mordedura de Loxosceles yucatana en un residente de Yucatán, México. El loxoscelismo cutáneo es el tipo más frecuente y menos severo. El presente caso se diagnosticó por medio de la sintomatología registrada en la historia clínica, la lesión inicial y la identificación de arañas L. yucatana. Este trabajo representa la primera descripción de un caso de loxoscelismo cutáneo con resolución favorable en Yucatán.

Loxoscelism occurs when the dermonecrotic venom produced by spiders of the genus Loxosceles, known as "violin spiders," enters a person's organism through their bite. In Mexico there is an underreporting of loxoscelism cases due to the absence of laboratory tests for its diagnosis and the complexity of the clinical picture. The aim of this paper is to describe a case of cutaneous loxoscelism caused by the bite of Loxosceles yucatana in a resident of Yucatan, Mexico. Cutaneous loxoscelism is the most frequent and less severe type. This case was diagnosed by means of the symptomatology registered in the medical records, the initial lesion, and the identification of L. yucatana spiders. This study represents the first description of a case of cutaneous loxoscelism with favorable outcome in Yucatan.

Brown spider (Loxosceles sp.) bite and COVID-19: A case report.

We present the case of a 32-year-old male patient hospitalized during the COVID-19 pandemic because of a Brown spider bite on his lower lip. The Brown spider accident occurred in southern Brazil; at hospital admission, the patient presented on his lip: edema, pustules, necrotic regions, and ulcerations. The patient complained of lower back pain, fever and dyspnea. Laboratory tests showed monocytosis, leukocytosis, neutrophilia, increased D-dimer levels, C-reactive protein, glutamate-pyruvate transaminase, delta bilirubin, creatine phosphokinase, procalcitonin, and fibrinogen. The patient was hospitalized and a multi-professional team carried out the treatment. The medical team diagnosed loxoscelism with moderate changes. The dentist treated the oral cavity. The patient began to develop nausea, vomiting, and desaturation episodes during hospitalization. A computed tomography of the chest was performed, which showed signs of viral infection. The RT-PCR test for COVID-19 was positive. The systemic conditions worsened (renal dysfunction, systemic inflammatory response, pulmonary complications). This condition may have resulted from the association of the two diseases (loxoscelism and COVID-19), leading to the patient's death. This case illustrates the difficulties and risks in treating patients with venomous animal accidents during the pandemic, and the importance of a multi-professional team in treating such cases.

Diethyl Azelate for the Treatment of Brown Recluse Spider Bite, a Neglected Orphan Indication.

BACKGROUND/AIM: Brown recluse spider bite releases hemolytic and cytotoxic phospholipase D to the wound that may cause necrosis or even death. We examined diethyl azelate (DEA), a plasma membrane fluidizer with a broad range of immunomodulatory activities, as a potential treatment for the brown recluse spider bite. MATERIALS AND METHODS: Topical DEA was used in emergency to treat brown recluse spider bites in a human subject. We subsequently evaluated the effects of DEA on hemolysis induced by the brown recluse spider venom, recluse recombinant phospholipase D (rPLD), and venoms from honey bee and moccasin snake, and on phospholipase A2 activity in the bee and snake venoms and in human urine. RESULTS: Topical DEA resolved the consequences of human brown recluse spider envenomation in two weeks. In vitro, DEA inhibited hemolysis caused by the brown recluse spider venom and rPLD and suppressed phospholipase A2 activity in a dose-dependent manner. CONCLUSION: DEA is a promising novel therapy for the brown recluse spider bite and perhaps even unrelated envenomations involving PLDs.

Suspected Brown Recluse Spider Envenomation: Missed Diagnosis and Delayed Treatment of Loxoscelism: A Case Report.

CASE: We report the case of a previously healthy 51-year-old man who presented to our hospital after worsening clinical appearance of his left ring finger, despite antibiotics and previous surgical drainage for suspected abscess at an outside institution 3 weeks ago. He was admitted to our hospital for surgical debridement and decompression. After suspicion of cutaneous loxoscelism based on the clinical record and corticosteroid administration, the patient presented a favorable evolution. CONCLUSION: Cutaneous loxoscelism caused by a spider bite is present in Europe, mainly in the Mediterranean area, and should be considered in cases of skin infections which do not respond to antibiotics.

First record of a case of cutaneous loxoscelism caused by violin spider (Loxosceles yucatana) bite in Yucatan, Mexico. / Primer registro de un caso de loxoscelismo cutáneo ocasionado por mordedura de araña violinista (Loxosceles yucatana) en Yucatán, México.

Loxoscelism occurs when the dermonecrotic venom produced by spiders of the genus Loxosceles, known as "violin spiders," enters a person's organism through their bite. In Mexico there is an underreporting of loxoscelism cases due to the absence of laboratory tests for its diagnosis and the complexity of the clinical picture. The aim of this paper is to describe a case of cutaneous loxoscelism caused by the bite of Loxosceles yucatana in a resident of Yucatan, Mexico. Cutaneous loxoscelism is the most frequent and less severe type. This case was diagnosed by means of the symptomatology registered in the medical records, the initial lesion, and the identification of L. yucatana spiders. This study represents the first description of a case of cutaneous loxoscelism with favorable outcome in Yucatan.

El loxoscelismo es ocasionado cuando el veneno dermonecrótico producido por las arañas del género Loxosceles, conocidas como «arañas violinistas¼, ingresa al organismo de una persona a través de su mordida. En México ocurre un subregistro de los casos de loxoscelismo por la ausencia de pruebas de laboratorio para su diagnóstico y la dificultad del cuadro clínico. El objetivo de este trabajo es describir un caso de loxoscelismo cutáneo ocasionado por mordedura de Loxosceles yucatana en un residente de Yucatán, México. El loxoscelismo cutáneo es el tipo más frecuente y menos severo. El presente caso se diagnosticó por medio de la sintomatología registrada en la historia clínica, la lesión inicial y la identificación de arañas L. yucatana. Este trabajo representa la primera descripción de un caso de loxoscelismo cutáneo con resolución favorable en Yucatán.

A protective vaccine against the toxic activities following Brown spider accidents based on recombinant mutated phospholipases D as antigens.

Accidents involving Brown spiders are reported throughout the world. In the venom, the major toxins involved in the deleterious effects are phospholipases D (PLDs). In this work, recombinant mutated phospholipases D from three endemic species medically relevant in South America (Loxosceles intermedia, L. laeta and L. gaucho) were tested as antigens in a vaccination protocol. In such isoforms, key amino acid residues involved in catalysis, magnesium-ion coordination, and binding to substrates were replaced by Alanine (H12A-H47A, E32A-D34A and W230A). These mutations eliminated the phospholipase activity and reduced the generation of skin necrosis and edema to residual levels. Molecular modeling of mutated isoforms indicated that the three-dimensional structures, topologies, and surface charges did not undergo significant changes. Mutated isoforms were recognized by sera against the crude venoms. Vaccination protocols in rabbits using mutated isoforms generated a serum that recognized the native PLDs of crude venoms and neutralized dermonecrosis and edema induced by L. intermedia venom. Vaccination of mice prevented the lethal effects of L. intermedia crude venom. Furthermore, vaccination of rabbits prevented the cutaneous lesion triggered by the three venoms. These results indicate a great potential for mutated recombinant PLDs to be employed as antigens in developing protective vaccines for Loxoscelism.

Viscerocutaneous Loxoscelism Manifesting with Myocarditis: A Case Report.

BACKGROUND Envenomation from the brown recluse spider (Loxosceles reclusa) is described to cause both local and systemic symptoms. We report a case of an adolescent boy who developed severe systemic loxoscelism, and his clinical course was complicated by myocarditis, which has not been previously reported in association with loxoscelism. CASE REPORT A 16-year-old boy presented with non-specific symptoms and forearm pain following a suspected spider bite, which subsequently evolved into a necrotic skin lesion. During his clinical course, he developed a characteristic syndrome of systemic loxoscelism with hemolysis, disseminated intravascular coagulopathy, and severe systemic inflammatory response syndrome, necessitating transfer to the Intensive Care Unit. The diagnosis was confirmed with an enzyme-linked immunosorbent assay that detected Loxosceles venom in the wound. Additionally, he developed pulmonary edema and cardiogenic shock secondary to myocarditis, which was confirmed with cardiac magnetic resonance imaging. Steroids and plasmapheresis were initiated to manage the severe inflammatory syndrome, and the myocarditis was treated with intravenous immunoglobulins, resulting in resolution of symptoms and improvement of cardiac function. CONCLUSIONS This is the first reported case of myocarditis associated with loxoscelism, providing evidence for Loxosceles toxin-associated cardiac injury, which has been previously described in animal models only. Furthermore, this case provides further support for the use of confirmatory testing in the clinical diagnosis of loxoscelism.

Hold the Chemo! Leukostasis, a Presentation of Brown Recluse Spider Bite: A Case Report.

Brown recluse spiders, also known as Loxosceles reclusa, are endemic to the Southwest and Central Midwestern United States. A bite from this spider can cause a range of clinical manifestations, anywhere from a painless papular lesion to life-threatening reactions. We report a possible spider bite presenting as leukostasis initially suspected to be acute leukemia. A 22-year-old female patient presented to the emergency department with confusion and right upper arm pain, redness, and swelling after a suspected spider bite. Initial labs showed WBC count of 103.5x10e3/µL, hemoglobin of 3.3 g/dL, positive Direct Coombs' test, creatinine of 1.8 mg/dL, transaminitis, and lactic acid of 20 mmol/L. Acute leukemia with leukostasis was suspected. She was started emergently on hydroxyurea in conjunction with prophylaxis for tumor lysis syndrome. However, peripheral smear showed left-shifted granulocytosis with lymphocytosis, monocytosis, and no blast cells or evidence of myelodysplasia. Bone marrow aspirate showed mildly hypercellular marrow with myeloid hyperplasia and no myelodysplasia. Flow cytometry analysis confirmed a left-shifted myeloid maturation pattern with 0.3% myeloblasts. BCR-ABL1 and JAK2 testing was negative. Hence, she had no evidence of leukemia but rather had leukostasis from a spider bite. Hydroxyurea was stopped and follow-up labs normalized. Sphingomyelinase D in the brown recluse spider venom is unique to Loxosceles and Sicarius and may be responsible for the unique clinical presentation of loxoscelism. The presentation of hyperleukocytosis complicated by shock with an unclear history poses a diagnostic challenge. In diagnostic uncertainty, consider delaying chemotherapy until a diagnosis can be confirmed to avoid potential harm.

Epidemiologia do araneísmo por Loxosceles e Phoneutria no município de Cruzeiro do Iguaçu ­ Paraná ­ Brasil / Epidemiology of araneism by Loxoceles and Phoneutria in the municipality of Cruzeiro of Iguaçu ­ Paraná ­ Brazil

Introdução: as aranhas são artrópodes encontrados com elevada frequência em diferentes ambientes, favorecendo a ocorrência de acidentes em áreas urbanas e rurais, em diferentes níveis de gravidade, sendo os acidentes mais frequentes provocados por aranhas do gênero Loxosceles e Phoneutria. No entanto, apesar dos riscos associados, pouco se sabe a respeito do araneísmo no interior do Paraná. Objetivo: o presente trabalho teve por objetivo analisar os dados epidemiológicos dos casos de araneísmo notificados nos anos de 2014 e 2015 no município de Cruzeiro do Iguaçu-Paraná. Metodologia: os dados foram obtidos através do levantamento junto a Secretaria de Saúde do município pelo Sistema de Informação de Agravos de Notificação. Resultados: foram notificados 23 acidentes com aranhas entre os anos de 2014 e 2015, sendo 10 acidentes relacionados ao gênero Loxosceles, 6 ao gênero Phoneutria, 5 acidentes com outras espécies não identificadas e outros 2 acidentes com agente causador ignorado. Conclusão: no município, os acidentes com Phoneutria e Loxosceles ocorrem o ano todo, contudo, há maior incidência de loxocelismo no mês de março. Dentre os casos notificados neste artigo, as vítimas acometidas por Loxosceles foram, em sua maioria, pessoas do sexo masculino, enquanto as vítimas de Phoneutria foram de ambos os sexos, preferencialmente indivíduos adultos com faixa etária entre 20 e 39 anos, para ambos os artrópodes relacionados. Ocorreu maior demora na busca por atendimento médico nos casos de acidentes com aranhas do gênero Loxosceles.

Introduction: spiders are arthropods found with high frequency in different environments, favoring the occurrence of accidents in urban and rural areas, at different severity levels, with the most frequent accidents being caused by spiders of the genus Loxosceles and Phoneutria. However, despite the associated risks, little is known about the araneísmo in the interior of Paraná. Objective: the present aimed to analyze the epidemiological data of the cases of araneism reported in the years of 2014 and 2015 in the city of Cruzeiro do Iguaçu-Paraná. Methodology: the data were obtained through a survey with Health Department of the municipality by the Aggravation Information System of Notification. Result: twenty three spider accidents were reported between 2014 and 2015, with 10 accidents related to the genus Loxosceles, 6 to the Phoneutria genus, 5 accidents with other unidentified species, and 2 other accidents with unknown causal agent. Conclusion: in the municipality, accidents with Phoneutria and Loxosceles occur all the year, however, there is a higher incidence of loxocellism in march. Among the reported cases in this article, the victims affected by Loxosceles were most males, while the victims of Phoneutria were of both sexes, preferably adult individuals with ages between 20 and 39 years, for both related arthropods. There was more delay in the search for medical care in cases of spider accidents of the genus Loxosceles.

Atypical systemic and dermatologic loxoscelism in a non-endemic region of the USA.

INTRODUCTION: Loxosceles reclusa (LR), commonly known as the brown recluse spider, is endemic to the south central United States. We present a case of LR envenomation in a healthy adult male outside the usual geographic range, with atypical dermatologic and delayed, prolonged systemic loxoscelism (LX). This case demonstrates the importance of expanding the depth of knowledge of LR envenomations. CASE REPORT: A previously healthy 27 year-old male presented to an emergency department (ED) in central Virginia two hours after a LR envenomation to his left proximal arm. He was treated with diphenhydramine and discharged on oral methylprednisolone for a 5-day taper. On post-bite Days 1 and 2, the patient developed subjective fevers, chills, arthralgias, and myalgias, followed by a blanching, pruritic, morbilliform rash throughout his trunk and lower extremities. Post-bite Day 3, the patient presented to the ED again because of marked erythema of face and the right lateral thigh, and posterior and anterior trunk. Vital signs and laboratory analysis were generally unremarkable. The patient was observed overnight, and discharged with a prescription for prednisone 60 mg per day. On post-bite Day 7, the patient noted a petechial rash on the palms and soles and returned to the ED with a fever of 102.6 °F, a heart rate of 130 beats per minutes, and systolic blood pressure ranging 80-90 mmHg. After considering this may be an atypical presentation of LX, corticosteroids were increased to methylprednisolone 1 mg/kg IV every 6 h. The patient's condition slowly improved and he was discharged on post-bite Day 10. On post-bite Day 24, he had nearly complete resolution of skin findings. CONCLUSIONS: LR envenomation can cause a variety of dermatological and systemic manifestations of toxicity. It is critical for toxicologists to be aware of the variety of presentations and findings to appropriately assess and treat LX.