Viabilidade de ovos de Aedes aegypti (Diptera, Culicidae) em diferentes condições de armazenamento em Manaus, Amazonas, Brasil

The viability of Aedes aegypti eggs was assessed in the Amazon region. The eggs were maintained under different conditions: indoors (insectarium) and outdoors (natural environment), as well as in different storage types (plastic cup, paper envelope, plastic bag) for different days. Egg viability was measured as the mean of hatchings observed from egg-bearing sheets of filter paper immersed in water, using three sheets randomly selected from each storage type and at both sites. There were significant differences in the viability of Ae. aegypti eggs with respect to the location (F=30.40; DF=1; P<0.0001), storage type (F=17.66; DF=2; P<0.0001), and time of storage (F=49.56; DF=9; P<0.0001). The interaction between storage site versus storage type was also significant (F=15.96; DF=2; P<0.0001). A higher hatching mean was observed for the eggs kept in the insectarium than for those outdoors (32.38 versus 7.46). Hatching rates of egg batches stored for 12 to 61 days ranged between 84 and 90%. A reduction was observed between 89 and 118 days, with values of 63 and 48%, respectively. With respect to type of storage, mean egg hatching was higher for the eggs in plastic cups (44.46). It was concluded that the viability of the eggs of Ae. aegypti in the Amazon region remains high up to 4 months, after which it declines drastically, although in this study hatching occurred for up to 8 months in very low percentages. © 2017, Instituto Internacional de Ecologia. All rights reserved

Eggs viability of Aedes aegypti Linnaeus (Diptera, Culicidae) under different environmental and storage conditions in Manaus, Amazonas, Brazil

Abstract The viability of Aedes aegypti eggs was assessed in the Amazon region. The eggs were maintained under different conditions: indoors (insectarium) and outdoors (natural environment), as well as in different storage types (plastic cup, paper envelope, plastic bag) for different days. Egg viability was measured as the mean of hatchings observed from egg-bearing sheets of filter paper immersed in water, using three sheets randomly selected from each storage type and at both sites. There were significant differences in the viability of Ae. aegypti eggs with respect to the location (F=30.40; DF=1; P<0.0001), storage type (F=17.66; DF=2; P<0.0001), and time of storage (F=49.56; DF=9; P<0.0001). The interaction between storage site versus storage type was also significant (F=15.96; DF=2; P<0.0001). A higher hatching mean was observed for the eggs kept in the insectarium than for those outdoors (32.38 versus 7.46). Hatching rates of egg batches stored for 12 to 61 days ranged between 84 and 90%. A reduction was observed between 89 and 118 days, with values of 63 and 48%, respectively. With respect to type of storage, mean egg hatching was higher for the eggs in plastic cups (44.46). It was concluded that the viability of the eggs of Ae. aegypti in the Amazon region remains high up to 4 months, after which it declines drastically, although in this study hatching occurred for up to 8 months in very low percentages

Seroprevalence of Brucella ovis-epididymitis, smooth-Brucella, leptospirosis, toxoplasmosis, and Maedi-Visna in sheep slaughtered in Minas Gerais State, Brazil.

Abstract: The present study aimed to estimate the prevalence of antibodies against Brucella ovis-epididymitis, smooth-Brucella, leptospirosis, toxoplasmosis and Maedi-visna in sheep slaughtered in Minas Gerais, Brazil and to study their simultaneous occurrence, including caseous lymphadenitis, at sheep and flock levels. The study was conducted at a sheep slaughterhouse with Federal Inspection Service. Sera from 594 animals from 21 flocks were collected, in 2007. The agar gel immunodiffusion (AGID) was employed to detect anti-B. ovis and anti-Maedi Visna antibodies, whereas Rose Bengal (RB) and the 2-mercaptoethanol test (2ME) were used to test anti-smooth Brucella antibodies. For the detection of anti-Leptospiraantibodies, sera were examined by microscopic agglutination test (MAT), while for the detection of IgG antibodies to Toxoplasma gondii ELISA was used. Prevalence of antibodies against smooth Brucella, B. ovis-epididimitis, Leptospiraspp., toxoplasmosis and Maedi-Visna found in sheep from Minas Gerais was 0.00%, 24.04%, 25.96%, 10.46% and 3.08%, respectively; whereas the seroprevalence in flocks was 0.00%, 80.95%, 90.48%, 71.43% and 23.81%, respectively. Moreover, when data on antibodies anti-Corynebacterium pseudotuberculosis, previously obtained, were included, about 60% of the flocks showed animals that were exposed to four or more of the studied agents. However, only 25.47% of the sheep exhibited simultaneously antibodies against more than one pathogen. Thus, data from the present study on sheep slaughtered in Minas Gerais, Brazil, showed no antibodies to smooth-Brucella and a low frequency of antibodies anti-Maedi Visna lentivirus, and a high and widespread seroprevalence of B. ovis, Leptospira spp., and T. gondii among animals and flocks [Soroprevalência de Brucella ovis, Brucella lisa, leptospirose, toxoplasmose e Maedi-Visna em ovinos abatidos em Minas Gerais, Brasil]. Resumo: O presente estudo teve como objetivo estimar a prevalência de anticorpos contra Brucella ovis (epididimite ovina), Brucellalisa, leptospirose, toxoplasmose e Maedi-visna em ovinos abatidos em Minas Gerais, Brasil, e estudar sua ocorrência simultânea, incluindo linfadenite caseosa, nos ovinos e nos rebanhos. O estudo foi realizado em um abatedouro de ovinos com Serviço de Inspeção Federal. Soros de 594 animais de 21 rebanhos foram coletados, em 2007. A imunodifusão em gel de ágar (IDGA) foi empregada para detectar anticorpos anti-B. ovis e anticorpos anti-Maedi Visna, enquanto o teste do antígeno acidificado tamponado (AAT) e o teste de 2-mercaptoetanol (2ME) foram utilizados para testar anticorpos anti-Brucella lisa. Para a detecção de anticorpos anti-Leptospira, os soros foram examinados pelo teste de aglutinação microscópica (MAT), enquanto que para a detecção de anticorpos IgG para Toxoplasma gondii, foi usado o ELISA. A prevalência de anticorpos anti-Brucella lisa, B. ovis, Leptospira spp., toxoplasmose e Maedi-Visna encontrados em ovinos de Minas Gerais foi de 0,00%, 24,04%, 25,96%, 10,46% e 3,08%, respectivamente; enquanto a soroprevalência em rebanhos foi de 0,00%, 80,95%, 90,48%, 71,43% e 23,81%, respectivamente. Além disso, quando dados de anticorpos anti-Corynebacterium pseudotuberculosis, previamente obtidos, foram incluídos, cerca de 60% dos rebanhos apresentaram animais expostos a quatro ou mais dos agentes estudados. No entanto, apenas 25,47% dos ovinos exibiram simultaneamente anticorpos contra mais de um patógeno. Assim, os dados do presente estudo sobre ovinos abatidos em Minas Gerais, Brasil, mostram que ausência de anticorpos anti-Brucella lisa e baixa frequência de anticorpos anti-Maedi Visna, e uma soroprevalência alta e generalizada de B. ovis, Leptospira spp. e T. gondii entre animais e rebanhos