Toxoplasma gondii antibody in domestic cats in Melbourne

OBJECTIVES: To determine the prevalence of Toxoplasma gondii in a population of domestic cats in Melbourne. DESIGN: An ELISA assay was used to measure T gondii antibody titres in 103 cats from north-eastern Melbourne. Cats were obtained from outer suburban areas (less than 30 km from the Melbourne GPO) and from rural areas (more than 30 km from the Melbourne GPO). RESULTS: Thirty-nine percent of cats were positive for T gondii IgG. Older cats tended to have higher antibody titres. There was no significant difference in the T gondii antibody titres between males and females, or between cats living in urban areas and cats from rural areas. CONCLUSIONS: A significant proportion of cats from Melbourne have been exposed to Toxoplasma. This may have implications for the health of wildlife and humans.     

Detection and quantitation of genetically modified maize (Bt-176 transgenic maize) by applying ligation detection reaction and universal array technology

We have applied the ligation detection reaction (LDR) combined with a universal array approach to the detection and quantitation of the polymerase chain reaction (PCR) amplified cry1A(b) gene from Bt-176 transgenic maize. We demonstrated excellent specificity and high sensitivity. Down to 0.5 fmol (nearly 60 pg) of PCR amplified transgenic material was unequivocally detected with excellent linearity within the 0.1-2.0% range with respect to wild-type maize. We suggest the feasibility of extending the LDR/universal array format to detect in parallel several transgenic sequences that are being developed for food applications.     

Assessment of the high-dose concept and level of control provided by MON 87701 × MON 89788 soybean against Anticarsia gemmatalis and Pseudoplusia includens (Lepidoptera: Noctuidae) in Brazil

BACKGROUND: Genetically modified MON 87701 × MON 89788 soybean (Glycine max), which expresses the Cry1Ac and EPSP‐synthase proteins, has been registered for commercial use in Brazil. To develop an Insect Resistance Management (IRM) program for this event, laboratory and field studies were conducted to assess the high‐dose concept and level of control it provides against Anticarsia gemmatalis and Pseudoplusia includens. RESULTS: The purified Cry1Ac protein was more active against A. gemmatalis [LC₅₀ (FL 95%) = 0.23 (0.15–0.34) µg Cry1Ac mL^?1 diet] than P. includens [LC₅₀ (FL 95%) = 3.72 (2.65–4.86) µg Cry1Ac mL^?1 diet]. In bioassays with freeze‐dried MON 87701 × MON 89788 soybean tissue diluted 25 times in an artificial diet, there was 100% mortality of A. gemmatalis and up to 95.79% mortality for P. includens. In leaf‐disc bioassays and under conditions of high artificial infestation in the greenhouse and natural infestation in the field, MON 87701 × MON 89788 soybean showed a high level of efficacy against both target pests. CONCLUSIONS: The MON 87701 × MON 89788 soybean provides a high level of control against A. gemmatalis and P. includes, but a high‐dose event only to A. gemmatalis. Copyright © 2012 Society of Chemical Industry     

Amphibians in a human-dominated landscape: the community structure is related to habitat features and isolation

We studied amphibian populations in a human-dominated landscape, in Northern Italy, to evaluate the effects of patch quality and isolation on each species distribution and community structure. We used logistic and linear multiple regression to relate amphibian presence during the breeding season in 84 wetlands to wetland features and isolation. Jackknife procedure was used to evaluate predictive capability of the models. Again, we tested the response of each species to habitat features related to the richest communities. Amphibian presence depends strongly on habitat quality and isolation: the richest communities live in fish-free, sunny wetlands near to occupied wetlands. The negative effects of isolation do not seem to be biased by spatial autocorrelation of habitat features. The system shows strong nestedness: amphibian persistence depends on the contemporary effects of species adaptability and mobility. The commonest species, the pool frog (Rana synklepton esculenta) and the Italian tree frog (Hyla intermedia), are able to move through the matrix using canals and hedgerows, and can maintain metapopulations across the landscape; the rarest species (newts and toads) are more sensitive to habitat alteration, and they are strongly affected by isolation effects. If human exploitation of the landscape continues, only few species, mobile and opportunistic, will persist in this landscape.     

Preparation and biological activity of four epiprogoitrin myrosinase-derived products

(5R)-5-Vinyl-1,3-oxazolidine-2-thione, (2S)-1-cyano-2-hydroxy-3-butene, and two diastereoisomeric erythro-(2S)- and threo-(2S)-1-cyano-2-hydroxy-3,4-epithiobutanes were prepared in pure form starting from (2S)-2-hydroxybut-3-enyl glucosinolate (epiprogoitrin). This glucosinolate was isolated in almost pure form using ripe seeds of Crambe abyssinica and then hydrolyzed under different conditions. The hydrolysis was carried out using either myrosinase immobilized on nylon, to produce (5R)-5-vinyl-1,3-oxazolidine-2-thione, or the endogenous myrosinase contained in defatted crambe meals, to produce the other epiprogoitrin-derived products. After purification and physicochemical characterization, all four myrosinase degradation products were tested for their biological activity. A bioassay on Lactuca sativa was chosen as a simple test to determine their apparent action on living tissues. (5R)-5-Vinyl-1,3-oxazolidine-2-thione negatively affected mainly root growth, whereas (2S)-1-cyano-2-hydroxy-3-butene affected the early phase of germination, and both (2S)-1-cyano-2-hydroxy-3,4-epithiobutane diastereoisomers appeared to negatively affect both germination and root growth at doses 5-10 times lower than those of (2S)-1-cyano-2-hydroxy-3-butene or (5R)-5-vinyl-1,3-oxazolidine-2-thione.     

A simple analytical method for dhurrin content evaluation in cyanogenic plants for their utilization in fodder and biofumigation

Cyanogenic plants have some potential as biocidal green manure crops in limiting several soilborne pests and pathogens. Sorghum (Sorghum bicolor (L.) Moench) and Sudangrass (Sorghum bicolor subsp. sudanense (P.) Stapf), in fact, contain the cyanogenic glucoside p-hydroxy-(S)-mandelonitrile-β-D-glucoside (dhurrin) as a substrate of its secondary defensive system able to release hydrogen cyanide following tissue lesions due to biotic or abiotic factors. Given that dhurrin content is correlated with the biofumigant efficacy of the plants, a high dhurrin content could be a positive character for utilization of sorghum and Sudangrass as biocidal green manure plants. For chemical characterization of the available germplasm, a simple, safe, and accurate method is necessary. In this paper, a new method for dhurrin analysis, based on methanol extraction and high-performance liquid chromatography, is reported and discussed. The feasibility of this analytical procedure was tested by evaluating dhurrin level in roots and stems during cultivation of four different sorghum and Sudangrass varieties in agronomic trials performed in 2008 in the Po valley (Italy). The dhurrin content ranged from 0.16 ± 0.04 to 7.14 ± 0.32 mg g(-1) on dried matter (DM) in stems and from 1.38 ± 0.02 to 6.57 ± 0.09 mg g(-1) on DM in roots, showing statistical differences among the tested germplasms that could be linked to the efficacy of their utilization as biofumigant plants. The method also opens new perspectives for the characterization of sorgum plants as fodder, for which the presence of dhurrin is considered to be negative for its well-known toxicity.     

Evaluation of colostral immunity in swine with commercial anti-leptospira polyvalent whole-bacteria vaccine

The intensity and duration of passive immunity against swine leptospirosis were investigated by the microscopic agglutination test and in vitro leptospira growth inhibition. Twenty-one females at first parturition were divided into three groups: Group A (n=08): received two doses with 30 days interval of the commercial anti-leptospira bacterin A. Group B (n=06) received two doses with 30 days interval of the commercial anti-leptospira bacterin B and Group C (n=07) was the control. In all groups the colostrums were collected. Blood collection of piglets was performed in four different ages. Agglutinin antibodies were equally detected in sera and colostrums for serovars Canicola, Grippotyphosa, Copenhageni, Icterohaemorrhagiae and Pomona (Group A) and Canicola, Copenhageni, Icterohaemorrhagiae, Pomona and Hardjo (Group B). Mean neutralizing antibodies titers were low. Passive immunity was low duration.