Risk factors to leptospirosis in cows in São Paulo State, Brazil

Risk factors associated to leptospirosis were identified in cows from São Paulo State. The State was divided into seven productive circuits from which 8,216 cows older than 24 months of age from 1,021 herds were sampled. For serological diagnosis of Leptospira spp. infection, the microscopic agglutination test (MAT) was carried out. Of the investigated herds, 718 (71.3%; 95% CI = 68.5% - 74.0%) presented at least one reactant animal at MAT to any serovar. Serovar Hardjo was the most prevalent, with 55.2% (95% CI = 51.4% - 58.9%) of the positive herds. Herd size, animal purchase, share pasture, presence of ovine and swine, and utilization of artificial insemination were identified as risk factors. Utilization of maternity pens was a protective factor against leptospirosis

Soroprevalência e fatores de risco para a leptospirose em cães de Campina Grande, Paraíba Seroprevalence and risk factors for leptospirosis in dogs from Campina Grande, State of Paraíba, Brazil

Investigou-se a prevalência de leptospirose em cães da cidade de Campina Grande, PB, e realizou-se um estudo de fatores de risco para a infecção. Foram examinadas 285 amostras de soro sangüíneo de cães colhidas durante a campanha de vacinação anti-rábica animal, conduzida em setembro de 2003. O diagnóstico da leptospirose foi realizado pela técnica de soroaglutinação microscópica, utilizando-se uma coleção de 22 sorovares. Para a caracterização do sorovar mais provável, levou-se em conta a titulação e a freqüência. A prevalência encontrada foi de 21,4% (IC 95% = 16,8%-26,6%), com maior freqüência dos sorovares autumnalis (7,4%), copenhageni (6%) e canicola (2,1%). A análise de regressão logística multivariada mostrou que os fatores de risco para a leptospirose foram: idade superior a um ano (odds ratio = 3,00; P = 0,006), raça não definida (odds ratio = 4,02; P = 0,011) e ocorrência de enchentes (odds ratio = 2,32; P = 0,039).The prevalence of leptospirosis was investigated in dogs from Campina Grande city, State of Paraíba, Brazil, and the risk factors for infection were analyzed. Two hundred and eighty five blood samples were collected from dogs during the rabies vaccination campaign, in September 2003. The diagnostic method run for leptospirosis was the microscopic agglutination test, using a batch of 22 leptospiral serovars. The most prevalent serovar was found crossing the results of frequency and titer of agglutinins. The prevalence was 21.4% (95% CI = 16.8%-26.6%) and most frequent reactant serovars were autumnalis (7.4%), copenhageni (6%) and canicola (2.1%). The multivariate logistic regression analysis showed that the risk factors for leptospirosis were: age older than one year (odds ratio = 3.00; P = 0.006), mixed breed (odds ratio = 4.02; P = 0.011) and occurrence of floods in the area (odds ratio = 2.32; P = 0.039)

Liquid-liquid equilibrium of water + PEG 8000 + magnesium sulfate or sodium sulfate aqueous two-phase systems at 35°C: experimental determination and thermodynamic modeling

Liquid-liquid extraction using aqueous two-phase systems is a highly efficient technique for separation and purification of biomolecules due to the mild properties of both liquid phases. Reliable data on the phase behavior of these systems are essential for the design and operation of new separation processes; several authors reported phase diagrams for polymer-polymer systems, but data on polymer-salt systems are still relatively scarce. In this work, experimental liquid-liquid equilibrium data on water + polyethylene glycol 8000 + magnesium sulfate and water + polyethylene glycol 8000 + sodium sulfate aqueous two-phase systems were obtained at 35°C. Both equilibrium phases were analyzed by lyophilization and ashing. Experimental results were correlated with a mass-fraction-based NRTL activity coefficient model. New interaction parameters were estimated with the Simplex method. The mean deviations between the experimental and calculated compositions in both equilibrium phases is about 2%