María Elisa Peichoto

National Institute of Tropical Medicine

Introducción: Las bacterias anaerobias ocupan diferentes nichos ecológicos y regulan la respuesta inmune innata del huésped; sin embargo, algunas de ellas se consideran patógenos oportunistas, ya que pueden invadir y producir daño. Objetivo: Determinar la prevalencia de bacterias anaerobias en muestras clínicas de pacientes internados y ambulatorio...

Resistance to antibiotics of clinical relevance in a hospital of Corrientes city. Carbapenemase-producing bacteria are involved in infections and colonizations and associated with high morbidity and mortality. Their identification facilitates the design and implementation of interventions aimed at reducing the risk of infections and deaths. The obj...

Se realizó un estudio entomológico y clínico-epidemiológico descriptivo de la serie de casos de erucismo ocurridos entre 2015 y 2018 en el Municipio de San Ignacio, Misiones, Argentina, debido al aumento extraordinario de accidentes informados por fuentes no sistemáticas. Con el fin de conocer la etiología, aspectos epidemiológicos, sintomatología...

Background: Among the Lepidoptera with medical importance in Brazil, larvae of Lonomia moth (Saturniidae: Hemileucinae) stand out by being the etiological agent of the lonomism, a form of erucism in which the most troubling symptoms include systemic hemorrhage that can lead to death. Methods: This study provides an epidemiological overview of ac...

With the aim to widen the current knowledge of toxinological implications of bites from rear-fanged snakes and biological roles of their venoms, this study focuses on the biochemical composition and toxic effects of the venom of Leptodeira annulata pulchriceps from Argentina. We analyzed the protein composition by electrophoresis and mass spectrome...

Lonomia Walker 1855 é um gênero de mariposas cujas larvas são amplamente conhecidas devido a ocorrência de contatos acidentais, podendo chegar a ser fatal aos seres humanos. Apesar da importância médica, poucos são os estudos com enfoque ecológico para o gênero. Com a finalidade de contribuir com informações a respeito de predadores de Lonomia spp....

Las orugas del género Lonomia Walker 1885 (Lepidoptera: Saturniidae), conocidas popularmente como ‘taturana’, son de amplio interés médico en Sudamérica por ser el agente etiológico del lonomismo, un tipo de envenenamiento causado por el contacto de los seres humanos con las estructuras urticantes de este género, y el cual se encuentra caracterizad...

Los lepidópteros constituyen uno de los grupos de insectos más ampliamente distribuidos y reconocidos en el mundo, sus orugas presentan variedad de formas y colores casi infinitas, increíblemente atractivas, algunas tan hermosas como venenosas. Dentro de la familia Saturniidae encontramos al género Lonomia, cuyas orugas son de amplio interés médico...

Most colubrid snake venoms have been poorly studied, despite the fact that they represent a great resource for biological, ecological, toxinological and pharmacological research. Herein, we explore the venom delivery system of the Aesculapian False Coral Snake Erythrolamprus aesculapii as well as some biochemical and toxicological properties of its...

Lonomia obliqua Walker 1855 (Lepidoptera: Saturniidae) is a species of moth which larvae are responsible for the lonomism, a form of envenomation that has been occurring in Brazil since the 1980s. Despite the importance in public health, the geographical distribution and their ecological aspects are unknown. Therefore, in the present study, we pres...

As larvas das mariposas do gênero Lonomia apresentam amplo interesse médico na América do Sul por serem o agente etiológico do lonomismo, uma forma de envenenamento causado pelo contato dos seres humanos com as estruturas urticantes das lagartas (fig. 1a e 1b). O lonomismo se manifesta por uma série de sintomas, podendo ocorrer um comprometimento s...

Among the Lepidoptera with medical importance in southern Brazil, larvae of Lonomia obliqua moth (Saturniidae: Hemileucinae) stand out by being the etiological agent of lonomism, a form of erucism in which the most troubling symptoms include systemic hemorrhage that can lead to death. In the last years, the scientific literature has attributed the...

Megalopygids Megalopyge lanata and Podalia orsilochus are common causative agents of accidents in agricultural workers. These accidents are provoked by dermal contact at their larval stage and are characterized by cutaneous reactions, such as burning pain, edema and erythema, typically mild and self-limited. There is very little information about t...

La Enfermedad Fúngica de las Serpientes (EFS) ha sido reportada en varias especies de serpientes cascabel y de colúbridos de Estados Unidos de América y Europa, pero no en América del Sur. Un espécimen del colúbrido sudamericano Xenodon merremii (conocido popularmente como falsa yarará) arribó al Servicio de Emergencia del Hospital de Clínicas de l...

Snakes are the major group of venomous vertebrates, and the rear-fanged snakes represent the vast majority of species and occur worldwide; however, relatively few studies have characterized their venoms and evaluated their potential hazards for humans. Herein we explore the protein composition and properties of the venom of the rear-fanged Green Pa...

The Lonomia obliqua moth is a species of broad medical interest because its larvae are etiological agents of lonomism, a form of erucism which can lead the patient to death. Accidents have been common in Brazil since the end of the 80s, appearing in the province of Misiones (Argentina) by the beginning of this millennium. In order to find areas of...

Dermal contact with Lepidoptera specimens at their larval stage (caterpillar) may cause systemic and/or local envenomation. There are multiple venomous species of them in Argentina, but their overall venom composition is poorly known. Lately, several cases of envenomation have been reported in the Misiones province, Northeastern Argentina. Thus, th...

Se define una unidad de actividad enzimática como la cantidad de proteína que causa un incremento de 0,005 unidad de absorbancia por minuto a 450 nm. Se define una unidad de actividad enzimática como la velocidad de disminución de absorbancia a 558 nm, que equivale a la cantidad de proteína que causa una disminución de una unidad de absorbancia por...

Parasitoides de orugas de importancia sanitaria criadas en laboratorio: hallazgos preliminares. OD Salomón1, D Soto1, R Dios2, A López1, MM Martínez1, M Antunez1, MA Quintana1, ME Peichoto1 1Instituto Nacional de Medicina Tropical, Argentina. 2Universidade de São Paulo, Brasil. Algunas larvas (orugas) de mariposas/polillas nocturnas (Lepidóptera) p...

Accidente P. fuscescens Hallazgo Este trabajo evidencia una amplia diversidad y distribución de orugas de importancia sanitaria en San Ignacio y sirve de base para desarrollar intervenciones de prevención. Las orugas de lepidópteros poseen cerdas especializadas como defensa contra los depredadores, las cuales en contacto con la piel humana pueden p...

Patagonfibrase is a hemorrhagic metalloproteinase isolated from the venom of the South American rear-fanged snake Philodryas patagoniensis, and is an important contributor to local lesions inflicted by this species. The tissue factor (TF)-factor VIIa complex, besides triggering the coagulation cascade, has been demonstrated to be involved in inflam...

Loxosceles gaucho spider venom induces in vitro platelet activation and marked thrombocytopenia in rabbits. Herein, we investigated the involvement of platelets in the development of the dermonecrosis induced by L. gaucho venom, using thrombocytopenic rabbits as a model. L. gaucho venom evoked a drop in platelet and neutrophil counts 4 h after veno...

The current study summarizes the postmortem examination of a specimen of Oxyrhopus guibei (Serpentes, Colubridae) collected in Iguazu National Park (Argentina), and found deceased a week following arrival to the serpentarium of the National Institute of Tropical Medicine (Argentina). Although the snake appeared to be in good health, a necropsy perf...

Lonomia obliqua (Walker, 1855) is a moth from the family Saturniidae, widely distributed in tropical rainforests of South America. In its larval stage (caterpillar) it is characterized by bristles that cover the animal's body. These structures are hard and branched spiny evaginations of the cuticle, underneath which a complex mixture of toxic molec...

Animal venoms represent a diverse source of potentially valuable therapeutic compounds due to the high specificity and the potent biological activity of many toxins. Snake venom toxins, particularly disintegrins and proteases from viper venoms, have yielded therapeutics with anti-cancer and hemostatic dysfunction activities. However, venoms from re...

Philodryas baroni-an attractively colored snake-has become readily available through the exotic pet trade. Most people consider this species harmless; however, it has already caused human envenomation. As little is known about the venom from this South American opisthoglyphous "colubrid" snake, herein, we studied its protein composition by sodium d...

Loxosceles venoms can promote severe local and systemic damages. We have previously reported that Loxosceles gaucho spider venom causes a severe early thrombocytopenia in rabbits. Herein, we investigated the in vitro effects of this venom and its sphingomyelinase fraction on the main functions of platelets. Whole venom and its fraction induced aggr...

Patagonfibrase is a P-III class metalloproteinase isolated from the venom of Philodryas patagoniensis, a South-American, rear-fanged 'colubrid' snake responsible for accidents with clinical significance. Since local inflammatory reactions are conspicuous signs of snakebites inflicted by this species and taking into consideration that most snake ven...

Leishmania parasites of several species cause cutaneous and visceral disease to millions of people worldwide, and treatment for this vector-borne protozoan parasite typically involves administration of highly toxic antimonial drugs. Snake venoms are one of the most concentrated enzyme sources in nature, displaying a broad range of biological effect...

The therapeutic effects of Argentine propolis ear drop formulation on canine otitis externa were evaluated. Forty-eight dogs with symptoms of otitis externa were randomly assigned to double-blinded, controlled clinical trial to evaluate the efficacy of topical formulation with propolis versus a topical placebo in the treatment of otitis externa. Th...

Patagonfibrase is a 57.5-kDa hemorrhagic metalloproteinase isolated from the venom of Philodryas patagoniensis (Patagonia Green Racer), a South American rear-fanged snake. Herein we demonstrate that patagonfibrase undergoes autolysis at its pH optimum (7.5) and at 37 degrees C, primarily producing a approximately 32.6 kDa fragment composed of disin...

Propolis is a mixture of complex chemical composition that possesses biological properties of great interest for therapeutic purposes. Different types of propolis exist, which differ in its chemical composition according to its botanical origin. At present, there is not a quality standard for propolis. For this reason, in this work the organoleptic...

Cysteine-rich secretory proteins (CRiSPs) are widespread in reptile venoms, but most have functions that remain unknown. In the present study we describe the purification and characterization of a CRiSP (patagonin) from the venom of the rear-fanged snake Philodryas patagoniensis, and demonstrate its biological activity. Patagonin is a single-chain...

Venoms of Colubridae snakes are a rich source of novel compounds, which may have applications in medicine and biochemistry. In the present study, we describe the purification and characterization of a metalloproteinase (patagonfibrase), the first protein to be isolated from Philodryas patagoniensis (Colubridae) snake venom. Patagonfibrase is a sing...

Following the bite of Philodryas olfersii latirostris Cope, 1862, a 29-year-old male herpetologist developed localized and burning pain, and minimal bleeding from the puncture marks of posterior maxillary teeth, which subsided rapidly. The victim developed no other local signs or symptoms. After few days the victim presented persistent severe rotat...

Very little is known about the systemic effects caused by Philodryas patagoniensis colubrid snake venom. In this work, this venom was tested for its ability to induce histopathological changes in rats after its intramuscular, subcutaneous or intravenous administration, by light microscopic examination of some organs (cerebellum, cerebrum, lung, liv...

Duvernoy's gland secretion of Philodryas patagoniensis exhibits high hemorrhagic activity, containing enzymes that are able to degrade the vascular wall. In this work we aim to determine if the secretion can also affect the hemostatic system by causing changes in blood coagulation. Procoagulant and coagulant activities were evaluated on plasma and...

Philodryas patagoniensis is a colubrid snake spread by all South America, but very little is known about the composition and biological activities of its Duvernoy's gland secretion. In order to characterize it, we studied edematogenic, dermonecrotic and myonecrotic activities. For edematogenic activity, solutions containing different amounts of sec...

Philodryas olfersii is found in South America, from Amazonas to Patagonia. It is important to characterize the venom of P. olfersii, who inhabits the North-East region of Argentina, since snake venoms are known to exhibit considerable variability in composition and biological activities. In this work, mice weighing 18-20 g (n = 4 for each experimen...

Colubrid snakes belonging to Philodryas genus, widespread all over South America, bring about lesions (swelling, ecchymosis, transient bleeding from the bite site punctures), that are similar to those produced by Bothrops species (yarará). In the present work we began the characterization of Philodryas patagoniensis venom. We examined if this venom...

INTRODUCCION Los venenos de serpientes de los géneros Crotalus y Bothrops provocan, entre otras, alteraciones de la hemostasia en el individuo inoculado [1] . Las sustancias responsables de este efecto son enzimas del tipo trombinas que actúan sobre el fibrinógeno convirtíéndolo en fibrina. Estructuralmente pertenecen a la familia de las serin-prot...