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Food allergens are capable of producing adverse reactions through multiple mechanisms of an allergic or non-allergic nature, and through different routes of exposure; generally by ingestion or contact, as in protein contact dermatitis or contact urticaria, including inhalation. Food allergy reactions, in turn, can be mediated by immediate hypersensitivity mechanisms, delayed hypersensitivity or mixed immediate-delayed mechanisms. The reference diagnostic method in food allergy is the double-blind placebo-controlled food challenge test (DBPCFC), but skin and serological tests are important in the clinical context. The diagnosis of immediate food allergy depends on well-standardized allergological tests, such as the skin prick test (SPT) or specific IgE dosing, which are ideally tested by food challenge testing. However, the diagnosis of delayed mechanism food allergy and mixed allergies, which combine both immune mechanisms, is more complex. Delayed hypersensitivity reactions are evaluated with the epicutaneous patch test, or patch testing, for the diagnosis of contact dermatitis. The atopy patch test is initially used for the investigation of inflammatory reactions, which may be linked to food allergens in patients with atopic dermatitis. It was later applied in other diseases, whose pathogenesis is mainly mediated by a mechanism of delayed hypersensitivity to protein allergens: eosinophilic esophagitis, enterocolitis induced by food proteins, protein contact dermatitis, contact urticaria, among other disorders.

Los alergenos alimentarios son capaces de producir reacciones adversas por múltiples mecanismos de naturaleza alérgica o no, y mediante distintas vías de exposición; generalmente por ingestión o por contacto, como en la dermatitis por contacto a proteínas o urticaria por contacto, incluso por inhalación. Las reacciones de alergia alimentaria, a su vez, pueden ser mediadas por mecanismos de hipersensibilidad inmediata, hipersensibilidad retardada o mecanismos mixtos inmediato-retardados. El método diagnóstico de referencia en alergia alimentaria es la prueba de desafío con alimentos a doble ciego controlado con placebo (DBPCFC), pero las pruebas cutáneas y serológicas son importantes en el contexto clínico. El diagnóstico de alergia alimentaria inmediata depende de pruebas alergológicas bien estandarizadas, como la prueba de prick (skin prick test-SPT) o la dosificación de IgE específica, que idealmente se comprueban mediante la prueba de provocación con alimentos. Sin embargo, el diagnóstico de alergia alimentaria de mecanismo retardado y alergias mixtas, que combinan ambos mecanismos inmunes, resulta más complejo. Las reacciones de hipersensibilidad retardada se evalúan con la prueba de parche epicutáneo, o patch testing, para el diagnóstico de las dermatitis por contacto. La prueba de parche de atopia se utiliza, inicialmente, para la investigación de reacciones inflamatorias, que pueden vincularse con alergenos alimentarios en pacientes con dermatitis atópica. Posteriormente fue aplicada en otras enfermedades, cuya patogenia es principalmente mediada por un mecanismo de hipersensibilidad retardada a alérgenos proteicos: esofagitis eosinofílica, enterocolitis inducida por proteínas alimentarias, dermatitis por contacto a proteínas, urticaria por contacto, entre otras alteraciones.

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BACKGROUND: Patients with allergic rhinitis to house dust mites have an increased risk of shrimp allergy. Der p 10 is a candidate biomarker to predict the risk of shrimp allergy among allergic rhinitis patients. OBJECTIVES: The aim of this study was to evaluate the diagnostic performance of anti-Der p 10 IgE as a predictor of shrimp allergy. METHODS: A nested case-control study was carried out with eighty-six allergic rhinitis patients sensitized to mite (Dermatophagoides pteronyssinus) and shrimp (Litopenaeu vannamei). Cases and controls were defined by anti-Der p 10 IgE results. Oral challenge with shrimp was used as the gold standard for the evaluation of diagnostic performance. RESULTS: All shrimp oral challenge test (OCT)-positive patients were positive for IgE against Der p 10. The level of anti-Der p 10 IgE >1.2 kUA/mL had the best diagnostic performance (sensitivity 100%, specificity 65%) Conclusion: Anti-Der p 10 IgE is useful for predicting shrimp allergy diagnosis and could reduce the requirement of an OCT.

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INTRODUCTION: Cross-reactivity between shrimp and house dust mite (HDM) proteins has been widely documented. In tropical region, shrimp (5-15%) and mite sensitization (80-95%) is prevalent in allergic patients. However, the clinical relevance of shrimp sensitization in patients with allergic rhinitis (AR) has been poorly studied. The aim of this study was to determine the prevalence and the clinical relevance shrimp IgE sensitization in AR patients sensitized to Dermatophagoides pteronyssinus. METHODS: The study was conducted in Medellin (Colombia). A cross-sectional study in patients with AR sensitized to HDM was performed in 3 steps: (i) assessment of IgE sensitization frequency to shrimp Penaeus azteca, Litopenaeus vannamei, and tropomyosin homologous allergens rDer p 10, rPen a 1, and rLit v 1, (ii) evaluation of the clinical relevance of shrimp sensitization using oral challenge test (OCT) and (iii) identification of possible risk factors for positive-OCT results. Ethical committee approval was obtained. RESULTS: From 443 patients with AR, 86 (19.4%) were sensitized to shrimp and 23 of them (26.7%) had shrimp allergy diagnosis. Thirty-six of the patients sensitized to shrimp (41.2%) reported not previously consumed this food and eleven of them had a positive-OCT (30.5%). There was not statistically significant difference in total IgE or sIgE (D. pteronyssinus, P. azteca, L. vannamei, rPen a 1, and rLit v 1) between OCT groups (positive vs. negative results). Anti-Der p 10 IgE was associated with risk for a positive-OCT in different multivariable scenarios. DISCUSSION/CONCLUSION: Our results suggest that in patients with HDM-associated AR and shrimp IgE sensitization is necessary to evaluate the clinical relevance of shrimp IgE even if the patient has never consumed shrimp because of cross-reactivity. Anti-Der p 10 could be a possible biomarker of clinical relevance to shrimp sensitization and could reduce the need for OCTs.

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OBJECTIVES: Nasal specific IgE (NsIgE) is the most common marker to identify type-2 inflammation in local allergic rhinitis (LAR). However, the comparison of NsIgE in different types of rhinitis, its frequency in tropical countries, and its diagnostic performance for predicting the outcome of a nasal challenge test (NCT) has had limited study. The main objective of this study was to explore the diagnostic performance of NsIgE to Dermatophagoides pteronyssinus (Der p) among different types of rhinitis and control subjects in a tropical population. METHODS: We evaluated the frequency of NsIgE, systemic atopy (serum sIgE and Skin Prick Test), and nasal eosinophils, and we performed nasal challenge tests (NCTs) with Der p in 3 groups of patients; rhinitis without atopy (RWoA) (n = 25), rhinitis with atopy (RWA) (n = 25), and control subjects (n = 18). RESULTS: NsIgE had a low sensitivity and specificity to predict a positive NCT in the RWoA group: 48% had NsIgE, but only 28% had a positive NCT. Among the RWA group 84% had NsIgE and 80% had a positive NCT; the association of NsIgE and positive NCT was high (>80%). In the control group 27.8% had NsIgE, but none had a positive NCT. CONCLUSIONS: NsIgE performs poorly in predicting NCT results in patients with non-allergic rhinitis. More methodical investigations are needed in this complex area of rhinitis. In patients with allergic rhinitis, NsIgE was useful in predicting a positive nasal challenge, but not superior to the systemic atopic test.

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Nile tilapia (Oreochromis niloticus) has always been considered more resistant to diseases compared to other fish species. However, in recent decades, this fish species has also been susceptible to many bacterial, fungal, parasitic, and nutritional diseases. In Brazil, streptococcosis is one of the main diseases that affect tilapia and has caused many economic losses. A resistance test was conducted with 93 tilapia of four varieties (UFLA strain and three commercial varieties: SC1, SC2, and SC3) to evaluate resistance to experimental inoculation with Streptococcus agalactiae. Each variety was distributed in five aquariums, with nine specimens of the same variety. Among the five aquariums, four housed fish were intraperitoneally inoculated with 10(7) CFU/fish of S. agalactiae and one aquarium harbored fish from the control group, which received 0.1 mL of sterile BHI (Brain Heart Infusion). Significant differences were observed in the survival rates accumulated at the end of the experiment (day 15), with values of 22, 36, 36, and 15% for SC1, SC2, SC3, and UFLA, respectively. The UFLA strain presented lower survival than other strains, which did not differ among the 15 days of challenge. These results demonstrate that there are animals with a better response to the resistance test than others.(AU)

A tilápia do Nilo (Oreochromis niloticus) sempre foi considerada mais resistente a doenças em comparação com outras espécies de peixes, porém, nas últimas décadas, essa espécie de peixe também foi suscetível a muitas doenças bacterianas, fúngicas, parasitárias e nutricionais. No Brasil, a estreptococose é uma das principais doenças que afetam a tilápia e causou muitas perdas econômicas. Um teste de resistência foi realizado com 93 tilápias de quatro variedades (linhagem UFLA e três variedades comerciais: SC1, SC2 e SC3) para avaliar a resistência à inoculação experimental com Streptococcus agalactiae. Cada variedade foi distribuída em cinco aquários, com nove espécimes da mesma variedade. Entre os cinco aquários, quatro peixes abrigados foram inoculados intraperitonealmente com 10(7) UFC / peixe de S. agalactiae e um aquário abrigou peixes do grupo controle, que receberam 0,1 mL de BHI estéril (infusão cardíaca cerebral). Diferenças significativas foram observadas nas taxas de sobrevivência acumuladas no final do experimento (dia 15), com valores de 22, 36, 36 e 15% para SC1, SC2, SC3 e UFLA, respectivamente. A linhagem UFLA apresentou menor sobrevivência que as demais, o que não diferiu entre os 15 dias de desafio. Esses resultados demonstram que existem animais com melhor resposta ao teste de resistência do que outros.(AU)

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Nile tilapia (Oreochromis niloticus) has always been considered more resistant to diseases compared to other fish species. However, in recent decades, this fish species has also been susceptible to many bacterial, fungal, parasitic, and nutritional diseases. In Brazil, streptococcosis is one of the main diseases that affect tilapia and has caused many economic losses. A resistance test was conducted with 93 tilapia of four varieties (UFLA strain and three commercial varieties: SC1, SC2, and SC3) to evaluate resistance to experimental inoculation with Streptococcus agalactiae. Each variety was distributed in five aquariums, with nine specimens of the same variety. Among the five aquariums, four housed fish were intraperitoneally inoculated with 10(7) CFU/fish of S. agalactiae and one aquarium harbored fish from the control group, which received 0.1 mL of sterile BHI (Brain Heart Infusion). Significant differences were observed in the survival rates accumulated at the end of the experiment (day 15), with values of 22, 36, 36, and 15% for SC1, SC2, SC3, and UFLA, respectively. The UFLA strain presented lower survival than other strains, which did not differ among the 15 days of challenge. These results demonstrate that there are animals with a better response to the resistance test than others.

A tilápia do Nilo (Oreochromis niloticus) sempre foi considerada mais resistente a doenças em comparação com outras espécies de peixes, porém, nas últimas décadas, essa espécie de peixe também foi suscetível a muitas doenças bacterianas, fúngicas, parasitárias e nutricionais. No Brasil, a estreptococose é uma das principais doenças que afetam a tilápia e causou muitas perdas econômicas. Um teste de resistência foi realizado com 93 tilápias de quatro variedades (linhagem UFLA e três variedades comerciais: SC1, SC2 e SC3) para avaliar a resistência à inoculação experimental com Streptococcus agalactiae. Cada variedade foi distribuída em cinco aquários, com nove espécimes da mesma variedade. Entre os cinco aquários, quatro peixes abrigados foram inoculados intraperitonealmente com 10(7) UFC / peixe de S. agalactiae e um aquário abrigou peixes do grupo controle, que receberam 0,1 mL de BHI estéril (infusão cardíaca cerebral). Diferenças significativas foram observadas nas taxas de sobrevivência acumuladas no final do experimento (dia 15), com valores de 22, 36, 36 e 15% para SC1, SC2, SC3 e UFLA, respectivamente. A linhagem UFLA apresentou menor sobrevivência que as demais, o que não diferiu entre os 15 dias de desafio. Esses resultados demonstram que existem animais com melhor resposta ao teste de resistência do que outros.

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White spot syndrome virus (WSSV) is one of the most virulent pathogens of cultured penaeid shrimp. Several control strategies are used commonly to mitigate the economic losses caused by the pathogen, such as application of antiviral products at farm level. One of the most practical method for the screening of potential anti-WSSV products is through challenge tests. Therefore, it is essential to develop simple, reproducible and effective bioassays able to simulate specific mortality levels. The purpose of this study was to develop a simple and reproducible bioassay that simulate different mortality levels by varying the proportion of WSSV-infected and noninfected shrimp tissues administered to susceptible shrimp during a per os challenge test. This method mimics one of the natural transmission routes of WSSV infection in shrimp and could be applied to identify potential antiviral products to different cultured shrimp species susceptible to WSSV. Here we report: •A simple and economic method to evaluate therapeutic antiviral products against WSSV through a challenge test, that uses different biomass amounts of WSSV-infected papilla.•Allows to simulate a wide and reproducible range of mortalities observed in shrimp farms.•A challenge test that simulates one mode of natural WSSV infection in shrimp.

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BACKGROUND: The advent of non-invasive methods provides a powerful alternative to stress studies as the use of stressful handling techniques is no longer needed. However, many factors influence hormone metabolism such as sex, diet, and metabolic rate. Thus, validation should be species- and matrix-specific. METHODS: To assess stress response in brown howler monkeys Alouatta clamitans, we adopted an ACTH challenge test and parallelism to provide physiological and laboratorial validation. Radioimmunoassay was used to measure fecal levels of corticosterone. RESULTS AND CONCLUSIONS: All challenged animals presented a peak in fecal glucocorticoids levels the day after the treatment, while control animals did not. There were no significant sex differences, but females with infants had higher levels of corticosterone. Corticosterone levels showed parallelism to the standard curve of the diagnostics kit. Collectively, the data suggest that the method was validated and is useful for monitoring stress, thereby helping in conservation programs both in captivity and in the wild. Transit time information may be coupled with travel distance in seed dispersal studies.

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OBJECTIVES: To assess correlations among variations in hemodynamic parameters during fluid volume loading. MATERIAL AND METHODS: Prospective observational study in 2 intensive care units. Sixty patients requiring intravenous fluids underwent challenge tests with 300 mL of crystalloids over a 48-hour period. Percent change in hemodynamic parameters after infusion was measured. We used hierarchical cluster and principal component analyses to explore correlations among changes in hemodynamic responses. RESULTS: The parameters that underwent the greatest median (interquartile range) percent changes were central venous pressure (24% [0.0%-41.7%]), pulse pressure (12.9% [0.0%-22.4%]), shock index (5.8% [2.7%-13.7%]), rate-pressure product (5.8% [3.8%-18.8%]), and systemic pressure difference (5.8% [-3.8%-18.8%]). There were strong correlations between percent changes in the following parameters: systolic blood pressure, pulse pressure, rate-pressure product, shock index, and systemic pressure difference. Central venous pressure was not correlated with any of the other hemodynamic parameters. CONCLUSION: The relationships between changes in hemodynamic parameters after fluid loading are complex and must be taken into account if fluids are infused during resuscitation.

OBJETIVO: Determinar la relación entre los parámetros hemodinámicos durante la expansión del volumen. METODO: Estudio observacional y prospectivo en dos unidades de cuidados intensivos. En las primeras 48 horas se realizó una prueba de volumen con 300 ml de cristaloides en 60 pacientes con indicación de fluidos endovenosos. Se evaluaron los cambios en los parámetros hemodinámicos después de la infusión de volumen, y las relaciones entre las variaciones se exploraron con los análisis de clústeres jerárquicos y de componentes principales. RESULTADOS: Los mayores porcentajes de variación se observaron en la presión venosa central [mediana 24% (rango intercuartil (RIC) 0,0-41,7%)], presión del pulso [mediana 12,9% (RIC 0,0-22,4%)], índice de shock [mediana 5,8% (RIC 2,7-13,7%)], producto presión del pulso-frecuencia cardiaca [mediana 5,8% (RIC ­3,8-18,8%)] y diferencia de presiones sistémicas [mediana 5,8% (RIC ­3,8-18,8%)]. Hubo una fuerte correlación entre las variaciones de la presión arterial sistólica, presión del pulso, producto presión del pulso-frecuencia cardiaca, índice de shock y diferencia de presiones sistémicas. La presión venosa central no se correlacionó con ningún parámetro hemodinámico. CONCLUSIONES: Las relaciones entre las variaciones que se producen en los parámetros hemodinámicas después del aporte de volumen son complejas, lo que se debe tener en cuenta durante la reanimación con volumen.

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This study aimed to determine the prevalence and populations of fungi in cake production chain. Besides, the growth potential of twelve fungal strains in different cake formulations was evaluated. Raw materials from two different batches (n=143), chocolate cakes (n=30), orange cakes (n=20), and processing environment air samples (n=147) were analyzed. Among the raw materials, wheat flour (3.2±0.3 log CFU per g) and corn meal (3.8±0.8 log CFU per g) belonging to batch #1 showed significant higher fungal counts (p<0.05). The fungal counts in the processing environment air reached up to 2.56 log CFU per m3 (p<0.05). The predominant fungi species in the industrialized cakes were Aspergillus flavus (28.15%), Penicillium citrinum (18.45%), Penicillium paxilli (14.56%), and Aspergillus niger (6.8%), which were also detected in the raw materials and processing environment air. Only Penicillium glabrum and Penicillium citrinum showed visible mycelium (>3mm) in the free of preservative cake formulation at 19th and 44th days of storage at 25°C, respectively. Revealing the biodiversity of fungi in ingredients, air and final products, as well as challenging final products with representative fungal strains may assist to implement effective controlling measures as well as to gather data for the development of more robust cake formulations.

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