Fatores associados à toxoplasmose na gestação / Factores asociados a la toxoplasmosis durante la gestación / Factors associated with toxoplasmosis in pregnancy

Objetivos: estimar a soroprevalência e analisar fatores associados a Toxoplasmose na gestação. Método: investigação epidemiológica, analítica e transversal com mulheres no pré-natal em Ribeirão Preto-SP. Os dados foram obtidos por meio de exames sorológicos e questionário. Modelo de regressão logística foi utilizado, com a seleção das variáveis independentes realizada por meio dos testes Exato de Fisher, ou Qui-quadrado, e t de Student, calculadas razões de chances brutas e ajustadas, com nível de significância de 5%. Resultados: amostra foi composta de 165 mulheres, com soroprevalência total, 34,5% [27,3; 41,8], reagentes para IgG. A chance de ser reagente ao anticorpo antitoxoplasma IgG é 1,09 vezes maior para cada ano a mais de idade; 19,48 para aquelas com Ensino Fundamental I incompleto; 4,41 para o contato direto com a terra. Conclusão: saneamento básico e a rede de serviços de saúde no município estudado favorecem a prevenção da Toxoplasmose na gestação.

Objetivos: estimar la seroprevalencia y analizar factores asociados a Toxoplasmosis en la gestación. Método: investigación epidemiológica, analítica y transversal con mujeres en el prenatal en Ribeirão Preto-SP. Los datos fueron obtenidos por medio de exámenes serológicos y cuestionario. Modelo de regresión logística fue utilizado, con la selección de las variables independientes realizada por medio de las pruebas Exacto de Fisher, o Chi-cuadrado, y t de Student, calculadas razones de probabilidades brutas y ajustadas, con nivel de significación del 5%. Resultados: muestra compuesta de 165 mujeres, con seroprevalencia total, 34,5% [27,3; 41,8], reactivos para IgG. La probabilidad de ser reactivo al anticuerpo antitoxoplasma IgG es 1,09 veces mayor para cada año a más de edad; 19,48 para aquellas con Enseñanza Fundamental I incompleto; 4,41 para el contacto directo con la tierra. Conclusión: saneamiento básico y la red de servicios de salud en el municipio estudiado favorecen la prevención de la Toxoplasmosis en la gestación.

Objectives: to estimate seroprevalence and analyze factors associated with Toxoplasmosis in pregnancy. Method: epidemiological, analytical and cross-sectional investigation with women in prenatal care in Ribeirão Preto-SP. Data were obtained through serological tests and questionnaire. Logistic regression model was used, with the selection of independent variables performed using the Fisher's exact test, or Chi-square test, and Student's t, calculated crude and adjusted odds ratios, with significance level of 5%. Results: sample was composed of 165 women, with total seroprevalence, 34.5% [27.3; 41.8], reagents for IgG. The chance of being reactant to the IgG antitoxoplasm antibody is 1.09 times higher for each year of age; 19.48 for those with incomplete Elementary School I; 4.41 for direct contact with the earth. Conclusion: basic sanitation and the network of health services in the municipality studied favor the prevention of Toxoplasmosis in pregnancy.

Olfactory response of Mahanarva spectabilis (Hemiptera: Cercopidae) to volatile organic compounds from forage grasses.

Several herbivorous insects utilize plant chemical cues to identify hosts for feeding. The role of smell in host plant detection by Mahanarva spectabilis (Distant) remains largely unknown. In this study, assays were applied to assess M. spectabilis olfactory responses to forage grasses (Pennisetum purpureum cvs. Roxo Botucatu and Pioneiro; Panicum maximum cvs. Makueni and Tanzânia; Hyparrhenia rufa cv. Jaraguá; Melinis minutiflora; Cynodon dactylon cv. Tifton; Brachiaria brizantha cv. Marandú; and Brachiaria decumbens cv. Basilisk). Bioassays were performed using a Y-olfactometer to evaluate the behavior of adult M. spectabilis to forage damaged and undamaged by insects. M. spectabilis preferred volatiles of undamaged Basilisk and Pioneiro. Repellent behavior by M. spectabilis to cospecifics was recorded for plant volatiles from damaged Marandú. The mixture of volatiles from undamaged forage grasses differed from that of forage grasses damaged by insects. Forage grasses showed a greater diversity of compounds after damage, including menthone, eucalyptol and camphor, which are compounds likely to cause loss of attractiveness or repellence. Our results demonstrate that M. spectabilis employs plant chemical cues in its choice of hosts. This fact may contribute to strategies of integrated management against this pest.

Do silicon and nitric oxide induce resistance to Mahanarva spectabilis (Hemiptera: Cercopidae) in forage grasses?

BACKGROUND: Great efforts have been made to identify grasses that are resistant to spittlebugs (Hemiptera: Cercopidae). However, the time required to develop and launch new cultivars is relatively long. The employment of resistance inducers is a current strategy that may be useful for the control of insect pests. This analysis evaluates the feasibility of using the chemical inducers silicon and nitric oxide to increase spittlebug resistance based on changes in forage grass vegetative characteristics and the biological traits of Mahanarva spectabilis (Distant, 1909). RESULTS: Mahanarva spectabilis nymphs and adults can cause significant damage to forage grasses. Furthermore, silicon and nitric oxide inducers were not sufficient to lessen this damage by positively influencing the growth and development of forage grasses. These inducers did not negatively alter the biological parameters of M. spectabilis or diminish its population. However, phenolic compound concentrations increased when forage grasses were treated with silicon or attacked by adult insects, but this parameter was not useful to predict spittlebug resistance. This fact suggests that the physiological and biochemical changes caused by silicon should be further studied. CONCLUSION: The current analysis demonstrated that application of the chemical inducers silicon and nitric oxide is currently not a viable strategy for the effective and economic management of M. spectabilis on Brachiaria ruziziensis, Pennisetum purpureum and Digitaria sp. © 2019 Society of Chemical Industry.

Tolerance to nymphs and adults of Mahanarva spectabilis (Hemiptera: Cercopidae) by forage plants in fertilized soils.

BACKGROUND: Several factors may degrade pastures, in particular, inadequate nutrient application and spittlebug attacks. Mahanarva spectabilis (Distant, 1909) (Hemiptera: Cercopidae), one of the species that occur in Brazil, is a limiting pest in forage production. This study analyzes the influence of fertilization with the macronutrients nitrogen, phosphorus and potassium (NPK) on the survival of M. spectabilis nymphs, and the effects of damage by nymphs and adults on the production, quality and regrowth capacity of the forages Brachiaria ruziziensis, Pennisetum purpureum and Digitaria sp. RESULTS: Fertilization of the forages differentially affected damage due to spittlebug herbivory. Attacks by nymphs and adults decreased chlorophyll content, plant regrowth and forage quality, and increased injury, regardless of fertilization. The availability of nutrients in the soil not only decreased fiber content, but also increased crude protein, chlorophyll content and regrowth, even when pest infested. Soil fertilization increased the capacity of forage plants to lessen, albeit not eliminate, the effects of injury by M. spectabilis. CONCLUSION: Forages in fertilized soil are more tolerant to attacks by M. spectabilis nymphs and adults. © 2019 Society of Chemical Industry.

Effect of silicon and acibenzolar-s-methyl on colored cotton plants infested or not with Aphis gossypii Glover (Hemiptera, Aphididae)

Effect of silicon and acibenzolar-s-methyl on colored cotton plants infested or not with Aphis gossypii Glover (Hemiptera, Aphididae). The aphid Aphis gossypii is an insect pest that causes damage mainly at the beginning of the cotton plant development. The effect of resistance inductors silicon and acibenzolar-s-methyl (ASM) on the development of colored cotton plants were researched in the presence and absence of A. gossypii. Three colored cotton cultivars were sown in pots and individually infested with 25 apterous aphids, 13 days after the application of the inductors. Fifteen days after plant emergence, the silicon was applied at a dosage equivalent to 3 t/ha and acibenzolar-s-methyl in 0.2 percent solution of the product BION 500®. After 21 days of infestation the following parameters were evaluated: plant height, stem diameter, dry matter of aerial part and root, and total number of aphids replaced. It was verified that the plant height was reduced in the presence of aphids and all variables were negatively affected by the application of ASM. However, silicon did not affect plant development.

Efeito do silício e do acibenzolar-s-methyl em plantas de algodão colorido infestadas ou não com Aphis gossypii Glover (Hemiptera, Aphididae). O pulgão Aphis gossypii é um inseto-praga que causa danos principalmente no início do ciclo do algodoeiro. Foram pesquisados os efeitos dos indutores silício e acibenzolar-s-methyl (ASM) no desenvolvimento de plantas de algodão colorido, na presença e ausência de A. gossypii. Três cultivares de algodão colorido foram semeadas em vasos e individualmente infestadas com 25 pulgões ápteros, 13 dias após a aplicação dos indutores. Quinze dias após emergência das plantas o silício foi aplicado na dosagem equivalente a 3 t/ha e o acibenzolar-s-methyl (ASM) na solução 0,2 por cento do produto BION 500®. Após 21 dias da infestação foram avaliados os seguintes parâmetros: altura da planta, diâmetro do caule, massa seca da parte aérea e da raiz, e o número total de pulgões repostos. Verificou-se que apenas a altura das plantas foi reduzida pela presença do pulgão e que todas as variáveis estudadas foram afetadas negativamente pela aplicação do ASM, porém não se observou efeito negativo do silício no desenvolvimento das plantas.