Thermal sensitivity of innate immune response in three species of Rhinella toads.

Immune activity is temperature-dependent and strongly related to thermal biology in ectotherms. Eurythermic, vs stenothermic, species commonly show a broader range of immune responses. Furthermore, the development of behavioral fever in ectotherms is correlated with improved immune function. Although amphibians generally show restricted capacity for thermoregulation in the field, behavioral fever has been documented in the laboratory for several anurans. However, the match between behavioral fever and improved immune response at fever thermal preferendum has still to be determined in these animals. In this study, we investigate the thermal sensitivity of the innate immune response, as measured by the plasma bacterial killing ability (BKA) against Aeromonas hydrophila, in three species of toads from genus Rhinella (R. schneideri, R. icterica and R. ornata) during their breeding season. Moreover, we show lipopolysaccharide-induced behavioral fever for R. ornata. The three species of toads showed an inverted U-shaped pattern of thermal sensitivity regarding BKA, with a high efficiency of immune response at temperatures around their thermal preferendum. The results partially corroborate the hypothesis that immune function is maximized at fever thermal preferendum, given that two of the species showed a maximal BKA performance temperature closer to fever than their normal thermal preferendum. Toads also showed an eurythermic pattern of immune response (large temperature breadth of BKA performance ≥95%; B95) during the breeding season. This large B95 encompasses much of the ecologically relevant temperatures, with the exception of those exhibited by two species that maintain activity during winter. Lastly, BKA was commonly suppressed at 37 °C, highlighting the importance of choosing ecologically relevant temperatures when conducting in vitro immunological tests.

Behavioral fever decreases metabolic response to lipopolysaccharide in yellow Cururu toads (Rhinella icterica).

Ectothermic vertebrates develop behavioral fever in response to bacterial products, with potential corresponding metabolic costs associated with immune stimulation. Although behavioral fever has been described in several taxa under laboratory conditions, some important questions regarding metabolic response to bacterial products at different temperatures and effectiveness of behavioral fever remain open. Many ectotherms, such as nocturnal anurans, may be active in the field at environmental conditions that restrict thermoregulation during the immune response. How does the metabolic response to bacterial products under ecologically relevant but unfavorable thermal field conditions compare to that measured in fever thermal preferendum? Additionally, are there differences in the partitioning of metabolic costs associated with immune stimulation and Arrhenius effect (biochemical reactions rate) at normal versus fever thermal preferendum? We compared the energy expenditure untreated and LPS-treated yellow Cururu toads (Rhinella icterica) at temperature corresponding to field activity during winter nights, and at normal and fever thermal preferendum. It was hypothesized that the metabolic response to LPS would be proportionally lower at higher body temperatures. To test these hypotheses, we measured temperature in the field during night using agar models, as well as normal and fever thermal preferendum of the toads within a thermal gradient. Subsequently, we measured the toad's metabolic rates at mean agar models temperature, as well as at normal and fever thermal preferendum. Lastly, we calculated the Metabolic response to LPS as the ratio between MRLPS/MRSaline in each of these mean temperatures. Our results show that metabolic rates do not increase in response to LPS at the agar models temperature typical of the winter nights under which theses toads maintain reproductive activity. Moreover, LPS treatment increased the metabolic costs relative to Arrhenius effects at normal thermal preferendum but not at fever thermal preferendum. In this way, metabolic response to LPS was comparative lower at fever than normal thermal preferendum in yellow Cururu toads.

Serodiagnosis of visceral and cutaneous leishmaniasis in human and canine populations living in Indigenous Reserves in the Brazilian Amazon Region.

INTRODUCTION:: Leishmaniasis is endemic to the Northern, Northeastern, Central-Western, and Southeastern regions of Brazil. We aimed to assess the epidemiological situation of leishmaniasis in humans and dogs in indigenous villages located in the States of Mato Grosso and Tocantins using a serological survey conducted in May 2011. METHODS:: Serum samples were collected from 470 humans and 327 dogs living in villages of the Urubu Branco and Tapirapé Karajá indigenous reserves. The samples were analyzed for the presence of Leishmania spp. antibodies using the indirect fluorescent antibody test (IFAT), enzyme-linked immunosorbent assay (ELISA) with a crude antigen (CA) and soluble antigen (SA), and Dual Path Platform (DPP®) immunoassay for canine visceral leishmaniasis. RESULTS:: Of 470 human samples tested, two (0.4%) were positive using IFAT. Among 327 dog samples tested, 28 (8.6%) were positive using ELISA CA, five (1.5%) using ELISA SA, two (0.6%) using IFAT, and none using DPP® immunoassay with Leishmania infantum chagasi antigen. When Leishmania amazonensis antigen was used, 20 (6.1%) samples were positive using ELISA CA and four (1.2%) using IFAT. CONCLUSIONS:: There was a low prevalence of infection in the region, and significant differences among the main serological methods used for the diagnosis of leishmaniasis. These findings indicated that the detection of Leishmania spp. requires further study and improvement.

Serodiagnosis of visceral and cutaneous leishmaniasis in human and canine populations living in Indigenous Reserves in the Brazilian Amazon Region

ABSTRACT INTRODUCTION: Leishmaniasis is endemic to the Northern, Northeastern, Central-Western, and Southeastern regions of Brazil. We aimed to assess the epidemiological situation of leishmaniasis in humans and dogs in indigenous villages located in the States of Mato Grosso and Tocantins using a serological survey conducted in May 2011. METHODS: Serum samples were collected from 470 humans and 327 dogs living in villages of the Urubu Branco and Tapirapé Karajá indigenous reserves. The samples were analyzed for the presence of Leishmania spp. antibodies using the indirect fluorescent antibody test (IFAT), enzyme-linked immunosorbent assay (ELISA) with a crude antigen (CA) and soluble antigen (SA), and Dual Path Platform (DPP®) immunoassay for canine visceral leishmaniasis. RESULTS: Of 470 human samples tested, two (0.4%) were positive using IFAT. Among 327 dog samples tested, 28 (8.6%) were positive using ELISA CA, five (1.5%) using ELISA SA, two (0.6%) using IFAT, and none using DPP® immunoassay with Leishmania infantum chagasi antigen. When Leishmania amazonensis antigen was used, 20 (6.1%) samples were positive using ELISA CA and four (1.2%) using IFAT. CONCLUSIONS: There was a low prevalence of infection in the region, and significant differences among the main serological methods used for the diagnosis of leishmaniasis. These findings indicated that the detection of Leishmania spp. requires further study and improvement.

Livestock markets play an important role in the cattle movement network in Pernambuco, Brazil / Feiras de gado desempenham papel importante na rede de trânsito de bovinos em Pernambuco, Brasil

The animal trade is an important risk factor that affects the spread of diseases among animals and herds. The goal of the present study was to characterize the cattle movement network in Pernambuco, Brazil, based on the animal movement permits (Guias de Trânsito Animal; GTAs) from 2012 to 2013, and identify the intensity of the commercial relationship between farm premises. A total of 737,950 GTAs were issued, and the movement of 3,481,185 cattle (1,688,585 in 2012 and 1,792,600 in 2013) was analyzed. Of the moved animals analyzed, 52.57% (1,829,907/3,481,185) were involved in the movement of cattle in or out of livestock markets, indicating that livestock markets played a major role in the network. Approximately 20% of the more-connected premises were responsible for approximately 87% of the movement related to sales and 95% of the movement related to purchases. Considering the important role of livestock markets and the intense cattle trade between farm premises, surveillance, and control measures could be more efficient if targeted to livestock markets and highly connected premises to prevent the spread of infectious diseases.(AU)

O comércio de animais é um importante fator de risco para a disseminação de doenças entre animais e rebanhos. O objetivo do presente estudo foi caracterizar a rede de movimentação de bovinos em Pernambuco, com base nas guias de trânsito animal (GTAs) de 2012 a 2013, e identificar a intensidade da relação comercial entre os estabelecimentos. Foram analisadas 737.950 GTAs emitidas, e as movimentações de bovinos totalizaram 3.481.185 animais (1.688.585 em 2012 e 1.792.600 em 2013). Um percentual de 52,57% (1.829.907/3.481.185) das movimentações de bovinos envolveu entrada ou saída de feiras de gado, indicando que as feiras desempenharam um papel importante na rede. Aproximadamente 20% dos estabelecimentos mais conectados foram responsáveis por aproximadamente 87% das movimentações relacionadas às vendas, e 95% das movimentações, relacionadas às compras. Considerando o importante papel das feiras e o intenso comércio de bovinos entre as propriedades, medidas de vigilância e controle podem ser mais eficientes se aplicadas em feiras e estabelecimentos altamente conectados, para prevenir a propagação de doenças infecciosas.(AU)

Infectious disease surveillance in animal movement networks: An approach based on the friendship paradox.

The network of animal movements among livestock premises is an important topological structure for the spread of infectious diseases. The central focus of this study was to analyze strategies for selecting premises based on the friendship paradox ("your friends have more friends than you do") - in which premises that neighbor randomly selected premises are sampled for surveillance or control - to determine whether these strategies are viable alternatives for the surveillance and control of diseases in scenarios with insufficient data on animal movement. To test the effectiveness of these strategies, we performed three sets of simulations. In the first set, we examined the risk of spreading an infectious disease using the cattle movement network of the state of Mato Grosso, Brazil. All tested strategies based on the friendship paradox have comparable performance to the hub control strategy (controlling premises that sold more animals) and superior performance to random sampling in terms of both reducing the risk of purchasing infected animals and the number of premises that need to be controlled. In the second and third sets of simulations, we observed that the friendship paradox strategies were more sensitive than the random sampling strategy to detect cases and disease, respectively. The survey of the entire animal movement network to identify animal premises with a key role in trade is not always possible, either because the data are insufficient or because informal trade is significant. If surveying the network is not possible, all approaches based on knowledge of the network become useless. As an alternative, knowing that there is a hidden movement network that follows rules inherent to all networks, such as the friendship paradox, can be used to our advantage. Strategies based on the friendship paradox do not assume knowledge of the animal movement network and therefore may be viable alternatives for the surveillance or control of infectious diseases in the absence of network information, thus optimizing the use of human and financial resources.

Acrodermatite enteropática / Acrodermatitis enteropathica

A acrodermatite enteropátíca é uma doença genética rara, de transmissão autossemíca recessíva o que se caracteriza por uma dermatite acral e periorifícíal, alopecia e diarréia. Os autores relatam e discutem um caso típico dessa entidade, enfatizando seus aspectos clínicos, evolutivos e terapêuticas e revisando brevemente a literatura.(au)

Pseudoxantoma elástico / Pseudoxanthona elasticum

Pseudoxantoma elástico: relato de um caso e revisão da literatura. Reportamos um caso típico de pseudoxantoma elástico com lesões cutâneas exuberantes e com comprometimento arterial periférico. Exame oftalmológico mostrou a presença de estrias angióides de retina e o estudo histopatológico de uma das lesões cutâneas confirmou o diagnóstico de pseudoxantoma elástico.