Interaction of Bacillus thuringiensis Cry1 and Vip3A proteins with Spodoptera frugiperda midgut binding sites

Vip3Aa, Vip3Af, Cry1Ab, and Cry1Fa were tested for their toxicities and binding interactions. Vip3A proteins were more toxic than Cry1 proteins. Binding assays showed independent specific binding sites for Cry1 and Vip3A proteins. Cry1Ab and Cry1Fa competed for the same binding sites, whereas Vip3Aa competed for those of Vip3Af. Copyright © 2009, American Society for Microbiology. All Rights Reserved.

Cyclodextrin glycosyltransferase production by the Bacillus sp., subgroup alcalophilus using a central composite design

Cyclodextrin glycosyltransferase (CGTase) activity was produced by the Bacillus sp., subgroup alcalophilus in a culture medium containing cassava starch. A central composite design and response surface methodology were used to study the influence of carbon source (cassava starch), nitrogen sources (yeast extract and tryptone) and sodium carbonate in the production medium. Assays were performed in 300 mL Erlenmeyer flasks containing 100 mL of production medium maintained in a shaker at 150 rpm at 35±1°C for 72 h of fermentation. The independent variables [0.75% cassava starch, nitrogen sources (0.375% yeast extract and 0.375% tryptone) and 1% Na2CO3] produced an enzyme activity of 96.07 U mL-1.© Academic Journals Inc.

Avaliação da reatividade cruzada entre antígenos de Leishmania spp e Trypanosoma cruzi na resposta sorológica de cães pela técnica de imunofluorescência indireta (RIFI)

Visceral Leishmaniasis (VL) is a zoonosis caused by Leishmania spp. protozoa. Dog is the main parasite's reservoir, especially in urban areas. Indirect Immunofluorescent Antibody Test (IFAT) is commonly used for canine visceral leishmaniasis (CVL) diagnosis, by detection of antibodies against the parasite. However, Trypanosoma cruzi (T.cruzi) cross reactions can occur in serological diagnosis. In order to evaluate the occurrence of cross reactions between antigens of Leishmania spp. and T.cruzi, 150 blood samples of CVL epidemiological inquiry positive dogs were collected and sera were tested by IFAT. Dogs were culled at Zoonosis Control Center of Bauru (SP), an endemic area for VL. Another 150 dogs' blood samples were collected in Botucatu (SP), a non endemic area for LV, and sera were also tested by IFAT. Serum samples of dogs from Bauru were positive, both for Leishmania spp. and for T. cruzi, showing high cross-reactions incidence, reinforcing the need of diagnosis confirmation by other tests. Serum samples of dogs from Botucatu demonstrated low prevalence of positive results by IFAT, both for Leishmania spp. and T.cruzi. However, despite the low number of positive serological results for these parasites, the epidemiological and serological investigation for LV and Chagas disease in dogs from Botucatu must be kept, considering the importance of dog as domestic reservoir for both parasites.

Detecção de Escherichia coli e Salmonella spp. em microbiota intestinal de Psittaciformes em fase de reabilitação para soltura

Escherichia coli is a bacteria of the Enterobacteriacea family and it is part of the enterical microflora of mammals and of many species of birds. Salmonella spp. also belongs to the family Enterobacteriacea, it is responsible for human feed toxinfection outbreaks and usually isolated from domestic and wild birds. The present study analyzed the frequency of both agents in Psittaciformes in rehabilitation process for wildlife reintroduction. In 89 birds analyzed, 19% were infected with E. coli and 1,12% with Salmonella spp. It was carried out an analysis of the profile of antibiotic resistance in which was observed the efficiency of estreptomicin, tetraciclin, trimetoprim and gentamicin over the samples. The samples of E. coli were submitted to the Congo Red Binding test and to the Hemolisis test and 70,6% of positive samples for the first test and 53% for the second one were observed.

Anticorpos anti-Leptospira spp. em animais selvagens do zoológico municipal de Ribeirão Preto, Estado de São Paulo, Brasil

Leptospirosis may affect all domestic and wild animals as well as human beings. Some serological studies have shown the involvement of wild species in the epidemiology of the disease. Once captive wild animals are not much studied, especially in Brazil, the present study aimed to detect anti- Leptospira spp. antibodies in animals from Ribeirão Preto city zoo, in São Paulo state, Brazil. Blood samples were collected from captive birds, fish, reptiles and mammals, sinanthropics and free-living animals and also from employees between March and October, 2006. Four hundred and three blood samples were obtained, 388 animals' samples (110 reptiles, 143 birds, 110 mammals and 25 fish) and 15 humans'. The sera were analysed by Microscopic Agglutination Test using 22 serovars from pathological leptospiras and two from non-pathological serovars. Among the animal samples, 339 were from captive animals, and 49 from free-living ones, captured with traps inside the zoo. One hundred and three (103/388 = 26.5%) samples reacted to leptospirosis, ninety-two (92/339 = 27.1%) samples were from captive animals and eleven (11/49 = 22.4%) from free-living ones. All humans' samples were negative. Serological titles varied from 40 to 5.120, with predominance of titles between 40 and 80 and the most frequent serovars were Patoc, Andamana, Canicola, Icterohaemorrhagiae and Panama.