Efficacy of florfenicol and intravenous fluid therapy for treatment of experimental salmonellosis in newborn calves Eficácia do florfenicol e da fluidoterapia parenteral no tratamento da salmonelose experimental em bezerros neonatos

The efficacy of florfenicol associated or not to intravenous fluid therapy for treatment of Salmonella Dublin-infected calves was determined. Twenty-four healthy 10 to 15-day-old Holstein calves were randomly allotted into four groups, with six animals each: control (group 1); infected with 10(8)CFU Salmonella Dublin and not treated (group 2); infected with 10(8)CFU Salmonella Dublin and treated with florfenicol (group 3); and infected with 10(8)CFU Salmonella Dublin and treated with florfenicol associated to fluid therapy (group 4). All animals were submitted to physical examination just before inoculation and every 24 hours, during seven days after experimental infection. Rectal swabs and blood samples were collected for Salmonella Dublin isolation and pH and blood electrolytes determination. The experimental infection with Salmonella Dublin induced clinical signs of salmonellosis, such as diarrhea and fever, and caused reduction in blood concentrations of pH, sodium, potassium and chlorides. The treated calves showed good clinical recovery, and the group treated with antibiotic in combination to fluid therapy presented a faster and more efficient correction of the hydro-electrolyte balance.Avaliou-se a eficácia terapêutica do florfenicol associado ou não à fluidoterapia intravenosa no tratamento de bezerros infectados experimentalmente com Salmonella Dublin. Foram utilizados 24 bezerros sadios da raça Holandesa com 10 a 15 dias de idade, distribuídos aleatoriamente em quatro grupos experimentais, constituídos por seis animais cada: controle (grupo 1); infectado com 10(8)UFC de Salmonella Dublin e não tratado (grupo 2); infectado com 10(8)UFC de Salmonella Dublin e tratado com florfenicol (grupo 3); e infectado com 10(8)UFC de Salmonella Dublin (grupo 4) e tratado com florfenicol associado à fluidoterapia. Todos os animais foram submetidos ao exame físico logo antes da inoculação e a cada 24 horas, durante sete dias após a infecção experimental. Foram colhidas amostras de suabes retais para o isolamento de Salmonella Dublin e amostras de sangue para determinação dos valores de pH e dosagem de eletrólitos sanguíneos. A infecção experimental com Salmonella Dublin induziu sinais clínicos de salmonelose, como diarreia e febre, e provocou redução do valor do pH e das concentrações sanguíneas de sódio, potássio e cloreto. Os bezerros submetidos aos tratamentos mostraram boa recuperação clínica, sendo que o grupo tratado com antibiótico combinado à fluidoterapia apresentou correção mais rápida e eficiente do equilíbrio hidroeletrolítico

Avaliação do impacto causado pela disponibilidade de 17β-estradiol livre ou complexado à β-ciclodextrina no ambiente aquático sobre Oreochromis niloticus (tilápia)

RESUMO Foram avaliados os efeitos tóxicos do hormônio 17β-estradiol (E2) livre e complexado à β-ciclodextrina (CD) sobre o comportamento e a fisiologia de tilápia (Oreochromis niloticus). Os peixes foram observados por 30 dias, em dois estágios do desenvolvimento (alevino e juvenil), pelo método ad libitum, para a confecção de um etograma. Posteriormente, juvenis foram divididos em três grupos: controle e expostos ao E2 (10ng/L) livre e complexado à β-ciclodextrina (β-CD:E2) por 90 dias. Foram avaliados o comportamento pelo método de varredura instantânea, o consumo de ração, o ganho de peso e a mortalidade em diferentes intervalos. Os alevinos e os juvenis apresentaram frequências de exibição comportamentais diferentes (P<0,05) nos eventos: Afastar (4,7±1,3 e 3,6±0,6%) e Ondulação de repulsão (2,3±0,9 e 1,3±1,0%). Os juvenis expostos ao complexo β-CD:E2 apresentaram aumento (P<0,05) na exibição dos comportamentos agressivos, como Afastar, Ataque caudal, Confronto prolongado, Perseguição, Fuga, e menor mortalidade, quando comparados ao grupo exposto ao E2 livre e controle. Pode-se concluir que a complexação do E2 com a β-CD alterou a toxicidade do E2, pois promoveu um aumento na frequência de exibição dos comportamentos agressivos e interferiu na mortalidade dos animais

Impact evaluation caused by disponibility of free and complexed 17β-estradiol into cyclodextrin in the aquatic environment in tilapia (Oreochromis niloticus)

<p></p><p>ABSTRACT Toxic effects of free and complexed 17β-estradiol (E2) hormone into β-cyclodextrin (CD) on the behavior and physiology of tilapia (Oreochromis niloticus) were evaluated. The fish were observed for 30 days in two stages of development (fingerling and juvenile) by the ad libitum method to make an ethogram. After this, juveniles were divided into three groups: control and exposed to free E2 (10ng/L) and complexed into β-cyclodextrin (β-CD:E2) for 90 days. The behavior was evaluated through scan sampling method, feed intake, body mass and mortality at different intervals. The fingerlings and juveniles showed behavioral patterns with different display frequencies (P<0.05) for events: Move Away (4.7±1.3 and 3.6±0.6%) and Waving Repulsion (2.3±0.9 and 1.3±1.0%). The juveniles exposed to β-CD:E2 complex showed a significant increase (P<0.05) in the frequency of display of aggressive behaviors as Move Away, Caudal Attack, Clash Extended, Chase, Escape and decrease of mortality when compared to group exposed to free E2 and control. In conclusion, complexation of E2 into β-CD modified E2 toxicity, because it promoted an increase in the frequency of display of aggressive behaviors and it affected the mortality of animals.</p><p></p

Avaliação clínica da infecção experimental de bezerros com Salmonella Dublin Clinical evaluation of experimental Salmonella Dublin infection in calves

<abstract language="eng">The clinical conditions of healthy calves infected with experimental 10(8)CFU of Salmonella Dublin were evaluated and the viability of the experimental model in disease induction in calves was verified. Twelve 10 to 15-day-old male Holstein calves were examined. They were allocated into two groups, control and experimentally infected with 10(8)CFU of Salmonella Dublin. Animals were submitted to clinical examination after inoculation and at every 12 hours, during seven days after the experimental infection. Samples of rectal swabs were collected for Salmonella Dublin isolation. All animals had severe diarrhea, with mucus and bleeding, 12 to 84 hours after the experimental infection with Salmonella Dublin, accompanied by fever, dehydration and respiratory signs. The isolation of Salmonella Dublin from rectal swabs occurred 12 hours after the infection. Two out of the six animals inoculated with Salmonella Dublin died with symptoms of enteritis, fibrinous pneumonia, centrilobular hepatic steatosis, hepatocyte necrosis, spleen congestion, interstitial nephritis, and tubular degeneration. Thus, the oral administration of 10(8)CFU of Salmonella Dublin induced clinical signs of salmonellosis in 10 to 15-day-old calves