Differential diagnosis of dog hookworms based on PCR-RFLP from the ITS region of their rDNA

Species of Ancylostoma infecting dogs and sometimes humans are sympatric in many parts of the world. The establishment of a specific molecular diagnostic tool is important, not only to refine information for epidemiological studies, but also to evaluate the efficacy of vaccine programmes and assist in the development of specific drug treatments. The ITS region from 20 specimens of A. braziliense, collected from three separate geographical areas of Brazil, and from 10 specimens of A. caninum, collected from the same area in Brazil were sequenced and analyzed. Alignment of sequences showed that this gene is highly conserved. The intraspecific polymorphism for both species was less then 1%, whereas the interspecific polymorphism was 6.2, 7.3 and 9.4% between A. ceylanicum and A. braziliense; A. caninum and A. ceylanicum and A. ceylanicum and A. braziliense, respectively. Among the three species it was 12.3%. This revealed the ITS region as highly conserved and consequently a good molecular marker for diagnostic studies. In this work, four restriction enzymes were used in a PCR-RFLP using the ITS region of rDNA, to establish a differential diagnosis which discriminates between three Ancylostoma species, A. braziliense, A. caninum and A. ceylanicum. The best pattern was given by the HinfI enzyme, which produced different fragment sizes for each of the three species. Furthermore, the diagnostic tool differentiates DNA extracted directly from faeces of Ancylostoma-infected dogs.     

Canine visceral leishmaniosis: a comparative analysis of the EIE-leishmaniose-visceral-canina-Bio-Manguinhos and the IFI-leishmaniose-visceral-canina-Bio-Manguinhos kits

This study evaluated the performance of the EIE-leishmaniose-visceral-canina-Bio-Manguinhos (EIE-LVC) kit and to compare it with that of the IFI-leishmaniose-visceral-canina-Bio-Manguinhos (IFI-LVC) kit. Four groups of dogs were studied: group 1 (G1), dogs with clinical signs indicative of CVL and testing positive for the parasite (n = 25); group 2 (G2), dogs with only a presumed diagnosis of CVL (n = 62); group 3 (G3), dogs that had never lived in an area where CVL is endemic and never received a blood transfusion (n = 16); group 4 (G4), dogs carrying other parasites: such as babesiosis (n = 4), ehrlichiosis (n = 6) and demodicosis (n = 1). G1 and G3 were used for the calculation of sensitivity and specificity, respectively. The EIE-LVC showed a sensitivity of 72% (IC 95%: 50.4-87.1%) and a specificity of 87.5% (IC 95%: 60.4-97.8%). The value of the kappa index was 0.975 (CI 95%: 0.926-1.024), which represents an excellent fit. For IFI-LVC, the sensitivity was 68.0% (CI 95%: 46.4-84.3%) and the specificity 87.5% (CI 95%: 60.4-97.8%). When the tests were conducted in parallel, sensitivity was 92.0% (CI 95%: 72.5-98.6%) and specificity 75.0% (CI 95%: 47.4-91.7%). However, when conducted consecutively, the tests showed a sensitivity of 48.0% (CI 95%: 28.3-68.2%) and a specificity of 100.0% (CI 95%: 75.9-99.4%). The analysis of clinically suspected dogs using IFI-LVC and EIE-LVC kits in parallel, revealed that 26/62 animals were positive. Cross-reaction was observed in a dog with demodicosis. These results lead to the following conclusions: (1) the performance of the EIE-LVC kit is not statistically different from the IFI-LVC and (2) the kits must be used in parallel if higher sensitivity is required, reducing the number of false-negative results.     

Anthelmintic activity of Azadirachta indica A. Juss against sheep gastrointestinal nematodes

Gastrointestinal nematode control has been performed through use of anthelmintics. However, the development of resistant populations has required research into new alternatives. There are popular reports about anti-parasitic activity of Azadirachta indica in animals and plants. The aim of this study was to evaluate the anthelmintic activity of A. indica after feeding sheep with the dried leaves. In this experiment, 40 sheep were allotted into four treatment groups. Group I received a treatment of A. indica dry leaves mixed in a concentrate at a rate of 0.1 g/kg dose for 3 months. Group II was treated with double the dose of Group I. Group III was treated with closantel (Diantel) at the manufacturer-recommended dose once at the beginning of the study and Group IV was not treated. To compare treatment effects, the following parameters were evaluated: egg count per gram of feces (EPG), worm burden, weight gain and haematocrit. EPG and worm burden results were statistically evaluated using the Kruskal-Wallis test. Haematocrit and live weight gain were submitted to analysis of variance (ANOVA) and the means evaluated by Tukey's test with 95% probability. None of the evaluated parameters of the treatment groups were statistically different when compared to the control group, demonstrating that, with the protocol used, A. indica has no anthelmintic effect.     

Diversity of the infracommunities of strongylid nematodes in the ventral colon of Equus caballus from Rio de Janeiro state, Brazil

Nematodes from the ventral colon of 31 adult horses, 24 males and 9 females, in the metropolitan region of the state of Rio de Janeiro were analysed. There were 53,444 (86.4%) adults of the total recovered strongylid nematodes. They belonged to 21 species of Cyathostominae and seven of Strongylinae. Larval forms made up 13.6% (8407) of the total recovered, and 49% of the strongylid nematodes were observed in ventral colon. The most prevalent and abundant species were Cyathostomum tetracanthum, Cylicocyclus nassatus, Cylicostephanus minutus, Cylicostephanus longibursatus, Cylicostephanus leptostomus, Cylicostephanus calicatus and Cylicostephanus goldi, corresponding to 93.2% of the total adult population; these species were classified as central species, except C. goldi; and other species were classified as secondary (n = 8) and satellite (n = 14). The low Green's aggregation index, presented to central species, indicated high dispersion because they were found in a greater number of infracommunities and were proven by the greater prevalence. Only 12.1% of the horses were uninfected or infected by a single species; the other infections were multiple, ranging from 3 to 23 species.     

Factors affecting somatic embryogenesis in conifers

This review seeks to examine the extreme response of isolated somatic plant cells of apical meristematic tissues of mature conifer trees towards specific stress conditions in vitro resulting in somatic embryogenesis.Signal molecules regulating embryo development have been described in angiosperms,but very little is known about somatic rejuvenation in conifers.Recent studies on cloning of mature conifers provide new perspectives on signal molecules on cellular dedifferentiation into the embryogenic pathway.Our recent studies show that signal molecules such as butenolide,calcium ions,salicylic acid,antioxidants,amino acids,triacontanol and 24-epibrassinolide all play an important role in the conversion of somatic cells into an embryogenic pathway in many recalcitrant pines.This constitutes a major breakthrough in forest biotechnology with many practical applications in clonal forestry.     

Effects of region, soil, land use, and terrain type on fuelwood properties of five tree/shrub species in the Sahelian and Sudanian ecozones of Mali

? Context

There is little information about inter- and intra-specific variation in fuelwood properties of trees/shrubs in West Africa.

? Aims

We studied variation in fuelwood properties of Balanites aegyptiaca, Combretum glutinosum, Guiera senegalensis, Piliostigma reticulatum, and Zizyphus mauritiana in the Sahelian and Sudanian ecozones of Mali.

? Methods

Trees were sampled on different soil (sandy, sandy/loam, or rocky), land use (parkland agroforest or woodland), and terrain (flat, temporarily flooded, or hill slope) types in five regions extending from the drier eastern to the more humid western parts of Mali. Basic density, volatile matter, fixed carbon, ash content, moisture content, gross calorific value, and fuel value index were measured for each tree and adjusted for tree age.

? Results

All fuelwood properties differed significantly among species, but there were significant species by region interactions. Most fuelwood properties of four species differed significantly among regions. Soil and/or land use type had significant effects on a few fuelwood properties of four species.

? Conclusion

In general, fuelwood production is recommended in all regions for G. senegalensis, in drier regions for B. aegyptiaca and C. glutinosum, in more humid regions for Z. mauritiana, and on rocky soils for all species. Fuelwood production of P. reticulatum is not recommended.     

Modeling Mediterranean forest fuels by integrating field data and mapping tools

Fire behavior modeling systems are important in predicting wildfire risk, fire growth, and fire effects. However, simulation software requires a new fuel modeling to include fuel treatments, prescribed fire and the transition to crown fire. The thirteen Rothermel models are insufficient in completely representing Mediterranean ecosystems. In this sense, the new American modeling includes five fuel types, requiring the acquisition of hybrid models made up of the mixture of grass and shrub and the grass or shrub mixed with litter from forest canopy. Respecting meteorological conditions and shrub characteristics, field studies have shown significant differences between American and Mediterranean models. As a consequence, the definition of new Mediterranean models requires the adjustment of specific parameters such as fuel load by category (live and dead) and particle size class (1-, 10- and 100-h time-lag), fuelbed depth and surface area-to-volume ratio. These new parameters were obtained in situ of sample itineraries, prescribed fires, and forest fires. The availability of this new modeling, validated on a field of regional scale, will facilitate preventive planning and management as well as an efficient application of suppression techniques, both ground and aerial operations, required in defending a territory against forest fires.     

Genetic mapping provides evidence for the role of additive and non-additive QTLs in the response of inter-specific hybrids of <Emphasis Type="Italic">Eucalyptus</Emphasis> to <Emphasis Type="Italic">Puccinia psidii</Emphasis> rust infection

Eucalypts are susceptible to a wide range of diseases. One of the most important diseases that affect Eucalyptus plantations worldwide is caused by the rust fungus Puccinia psidii. Here, we provide evidence on the complex genetic control of rust resistance in Eucalyptus inter-specific hybrids, by analyzing a number of full-sib families that display different patterns of segregation for rust resistance. These families are totally unrelated to those previously used in other inheritance studies of rust resistance. By using a full genome scan with 114 genetic markers (microsatellites and expressed sequence tag derived microsatellites) we also corroborated the existence and segregation of a resistance locus, explaining 11.5% of the phenotypic variation, on linkage group 3, corresponding to Ppr1. This find represents an additional validation of this locus in totally unrelated pedigree. We have also detected significant additive × additive digenic interactions with LOD >10.0 on several linkage groups. The additive and epistatic QTLs identified explain between 29.8 and 44.8% of the phenotypic variability for rust resistance. The recognition that both additive and non-additive genetic variation (epistasis) are important contributors to rust resistance in eucalypts reveals the complexity of this host-pathogen interaction and helps explain the success that breeding has achieved by selecting rust-resistant clones, where all the additive and non-additive effects are readily captured. The positioning of epistatic QTLs also provides starting points to look for the underlying genes or genomic regions controlling this phenotype on the upcoming E. grandis genome sequence.