Spatial distribution of soil contamination by Toxoplasma gondii in relation to cat defecation behaviour in an urban area

In urban areas, there may be a high local risk of zoonosis due to high densities of stray cat populations. In this study, soil contamination by oocysts of Toxoplasma gondii was searched for, and its spatial distribution was analysed in relation to defecation behaviour of cats living in a high-density population present in one area of Lyon (France). Sixteen defecation sites were first identified. Cats were then repeatedly fed with marked food and the marked faeces were searched for in the defecation sites. Of 260 markers, 72 were recovered from 24 different cats. Defecation sites were frequented by up to 15 individuals. Soil samples were also examined in order to detect the presence of T. gondii using real-time PCR. The entire study area was then sampled according to cat density and vegetation cover type. Only three of 55 samples were positive and all came from defecation sites. In a second series of observations, 16 defecation sites were sampled. Eight of 62 samples tested positive, originating in five defecation sites. Laboratory experiments using experimental seeding of soil showed that the inoculated dose that can be detected in 50% of assays equals 100-1000oocysts/g, depending on the strain. This study shows that high concentrations of oocysts can be detected in soil samples using molecular methods and suggests that spatial distribution of contamination areas is highly heterogeneous. Positive samples were only found in some of the defecation sites, signifying that at-risk points for human and animal infection may be very localised.     

Childhood absence epilepsy with tonic-clonic seizures and electroencephalogram 3-4-Hz spike and multispike-slow wave complexes: linkage to chromosome 8q24.

Childhood absence epilepsy (CAE), a common form of idiopathic generalized epilepsy, accounts for 5%-15% of childhood epilepsies. To map the chromosomal locus of persisting CAE, we studied the clinical and electroencephalographic traits of 78 members of a five-generation family from Bombay, India. The model-free affected-pedigree member method was used during initial screening with chromosome 6p, 8q, and 1p microsatellites, and only individuals with absence seizures and/or electroencephalogram 3-4-Hz spike- and multispike-slow wave complexes were considered to be affected. Significant P values of .00000-.02 for several markers on 8q were obtained. Two-point linkage analysis, assuming autosomal dominant inheritance with 50% penetrance, yielded a maximum LOD score (Zmax) of 3.6 for D8S502. No other locus in the genome achieved a significant Zmax. For five smaller multiplex families, summed Zmax was 2.4 for D8S537 and 1.7 for D8S1761. Haplotypes composed of the same 8q24 microsatellites segregated with affected members of the large family from India and with all five smaller families. Recombinations positioned the CAE gene in a 3.2-cM interval.     

Antagonistic Yeasts for Biocontrol of the Banana Postharvest Anthracnose Pathogen Colletotrichum musae

The biocontrol potentials of Candida tropicalis YZ1, C. tropicalis YZ27 and Saccharomyces cerevisiae YZ7 against the postharvest anthracnose pathogen Colletotrichum musae were investigated. Treatments with all the three biocontrol agents (1 × 10⁸ CFU/ml) significantly reduced the natural anthracnose disease severity of harvested banana fruits stored at ambient condition. Germination and survival of C. musae spores were markedly inhibited by all the three yeast strains in in vitro tests. The niche overlap index (NOI) was used to determine the interaction between the antagonists and C. musae, and the results (high NOI values) suggest competitive exclusion of C. musae by the yeast strains. C. tropicalis YZ27 inoculated on banana wounds exhibited rapid colonization and maintenance of its population on the inoculated site. The biocontrol efficacy was also observed as a function of concentration of the antagonist applied. The fruits treated with C. tropicalis YZ27, 36 h before pathogen inoculation, showed the best results with 96.0% disease inhibition followed by those treated 24 h before with 84.0% inhibition. The above results point to competition for nutrients and space as the main mechanism of antagonistic action of C. tropicalis YZ27 against C. musae.     

Introgression of powdery mildew resistance from Aegilops triuncialis into wheat through induced homeologous pairing

Journal of Plant Biochemistry and Biotechnology - Powdery mildew is a serious fungal disease of wheat caused by Blumeria graminis f. sp. tritici. Chromosome 5U of Aegilops triuncialis carrying...