Selected pathological, immunohistochemical and ultrastructural changes associated with an infection by Diphyllobothrium dendriticum (Nitzsch, 1824) (Cestoda) plerocercoids in Coregonus lavaretus (L.) (Coregonidae)

The pathological changes induced by an infection of Diphyllobothrium dendriticum (Nitzsch, 1824) plerocercoids in powan, Coregonus lavaretus (L.), from Loch Lomond, Scotland, were assessed using immunohistochemical and ultrastructural techniques. In a sample of 26 powan, the occurrence of encysted plerocercoids of D. dendriticum on the outer surface of the stomach was 38.5% (n = 10) with the number of cysts ranging from 4 to 15 and measuring 4.2 +/- 1.0 mm x 3.4 +/- 0.9 mm (mean +/- SD). Histological examination of intestinal samples also revealed plerocercoids (2-21) encapsulated within a proliferation of mesenteric fibrous tissues of the gastric wall and, occasionally, by the gut lamina propria-submucosa and lamina muscularis. In section, cysts were tri-layered and were formed from a series of concentric whorls of fibroblast and collagen fibre-based connective elements. The extent of necrosis within each muscle layer and the serosa of the stomach differed, notably within the latter that was marked by a chronic inflammatory reaction and fibrosis. Within the cyst and around it, a large number of degranulating mast cell/eosinophilic granule cells were seen, in addition to melano-macrophage centres. Immunohistochemical staining of sections of infected stomach revealed a high density of elements, in close proximity to plerocercoids, staining positive for serotonin, bombesin, substance P and galanin. Uninfected material did not present the same levels of activity. Sections through both infected and uninfected tissue were also tested for elements containing vasoactive intestinal peptide, met-enkephalin, calcitonin gene-related peptide, neuropeptide Y and nitric oxide synthase, but these were absent.     

Side effects of botanical insecticides on predatory mite Amblyseius andersoni (Chant)

The effects of the botanical insecticides Biopiren plus, Piresan plus and Neemazal T/S on the predatory mite Amblyseius andersoni (Chant) were tested under laboratory, semi-field, and field conditions. The tests carried out in the laboratory allowed detection of the direct toxicity on eggs and females as well as the effects on fecundity, whereas semi-field trials assessed their residual toxicity. In laboratory and semi-field tests, pyrethrins, particularly Piresan plus, proved to have the highest toxicity with E value, concerning both female mortality and fecundity, of 100?% and 45?%, respectively. The same product tested in the field only caused a significant reduction in the phytoseiid population shortly after the treatment. The relevant escape rate registered in semi-field tests could explain the lack of phytoseiid eradication in the field after treatment with pyrethrins.     

Apple cultivars acceptance by Dysaphis plantaginea Passerini (Homoptera: Aphididae)

The development time, longevity, and fecundity of Dysaphis plantaginea were measured on six apple cultivars (Golden delicious, Red delicious, Renetta canada, Florina querina, Golden lasa, and Golden orange) under controlled conditions, in order to establish the life tables of D. plantaginea on the different cultivars and to evaluate the tolerance of the cultivars against this pest. The intrinsic rates of increase (r _m) were 0.07 and 0.11 day⁻¹ on F. querina and G. orange, respectively. On the other four cultivars, rates ranged between 0.22 and 0.26 day⁻¹, with the maximum value registered on G. lasa. All the biological and demographic parameters evaluated, i.e. survival of larvae (M = 5.8–72.2%), mean generation time (T = 14.94–20.62 days), and net reproduction rate (R ₀ = 4.23–47.37), show that G. orange and F. querina are tolerant cultivars while R. delicious, R. canada, G. lasa, and G. delicious are susceptible hosts.     

A rapid multiplexed chemiluminescent immunoassay for the detection of Escherichia coli O157:H7, Yersinia enterocolitica, Salmonella typhimurium, and Listeria monocytogenes pathogen bacteria

A simple and rapid multiplexed sandwich chemiluminescent enzyme immunoassay has been developed for the simultaneous detection of Escherichia coli O157:H7, Yersinia enterocolitica, Salmonella typhimurium, and Listeria monocytogenes. To achieve the multiplexed detection of the four pathogens, a new polystyrene 96 well microtiter plate format has been designed, in which each main well contains four subwells in the bottom. The monoclonal antibodies specific for each bacteria were separately immobilized in each subwell. When the samples were added to the main wells, the bacteria able to specifically bind to the corresponding monoclonal antibody were captured in one of the four subwells. Subsequently, a mixture of peroxidase-labeled polyclonal antibodies against the four bacteria was added and the peroxidase activity of the bound polyclonal labeled antibodies in each well was measured by an enhanced luminol-based chemiluminescent cocktail using a low-light charge-coupled imaging device. The assay was simple and fast, and the limit of quantification was in the order of 104-105 CFU/mL for all bacterial species. The accuracy of the method, evaluated by comparison of the results with a conventional culturing methodology, was satisfactory, with recovery values ranging from 90 to 120%. This method can be used as a screening test to evaluate the presence of these pathogen bacteria in different foodstuffs.     

One-step triplex-polymerase chain reaction assay for the authentication of yellowfin (Thunnus albacares), bigeye (Thunnus obesus), and skipjack (Katsuwonus pelamis) tuna DNA from fresh, frozen, and canned tuna samples

A one-step triplex-polymerase chain reaction (PCR)-based assay was developed to discriminate between three tuna species, Thunnus albacares, Thunnus obesus, and Katsuwonus pelamis, even in highly processed food samples such as canned or cooked tuna. Diagnostic nucleotides were identified by direct sequencing and alignment of part of the mitochondrial cytochrome b gene of 30 authenticated exemplars, which allowed us to evaluate intraspecific variation and the genetic distance between three tuna species. The assay relies on a one-step triplex-PCR reaction in which in a single tube species-specific amplification products are generated only in the presence of the correct template nucleic acid and the species of origin of the DNA is indicated by the distinctive size of the PCR product. The identification of tuna species can be performed with a good accuracy, low cost, and with potential automation for large-scale high-throughput screenings in small in-house laboratories.     

Antioxidant and antimutagenic properties of Hibiscus tiliaceus L. methanolic extract

The genus Hibiscus thrives in a variety of climates and produces a diversity of natural compounds with bioactive properties. We have studied the chemical composition and the in vivo antioxidant properties of Hibiscus tiliaceus L. methanolic flower extract, as well as its mutagenic/antimutagenic effects. Vitamin E and some stigmasterol derivatives that might confer an antioxidant effect to the extract were present. Treatment with this extract protected several Saccharomyces cerevisiae strains defective in antioxidant defenses against H2O2 and t-BOOH cytotoxicities, showing a clear antioxidant activity. The effect is the same for all strains used, independent of the antioxidant defense disrupted, suggesting that protection may be due to molecules that act as versatile and wide spectrum nonenzymatic antioxidants, such as vitamins or phytosterols. The extract was not mutagenic in either Salmonella typhimurium or S. cerevisiae and showed a significant antimutagenic action against oxidative mutagens in S. cerevisiae.     

Changes in the neuromodulators of the diffuse endocrine system of the alimentary canal of farmed rainbow trout, Oncorhynchus mykiss (Walbaum), naturally infected with Eubothrium crassum (Cestoda)

A histopathological and immunohistochemical study on the intestines of 45 specimens of farmed rainbow trout, Oncorhynchus mykiss (Walbaum), from Loch Awe, Scotland, revealed a number of cellular deviations in individuals naturally infected with the pseudophyllidean cestode Eubothrium crassum (Bloch, 1779). Twenty-five individuals (55.5%) were infected with an average worm burden of 18.84 +/- 4.06 (mean +/- SE) cestodes per host (range, 2-80 worms; total 471 worms). The cestodes, measuring an average 8.23 +/- 1.10 cm (mean +/- SE; range, 5.3-13.0 cm) in length, were found attached by their scolices to the mucosal lining of the distal portion of the pyloric caeca. Within the caeca, the strobila evoked a mild catarrhal enteritis, namely an enhanced mucus production with epithelial cellular desquamation, a leucocytic infiltration of the lamina propria-submucosa and vacuolization of the intestinal epithelial cells. Eosinophilic granular cells of the stratum granulosum exhibited granular depletion, while within the catarrh, the presence of a high number of rodlet cells was noticed. Immunohistochemically, the occurrence of E. crassum caused a significant reduction in the number of bombesin-, gastrin-releasing peptide and glucagon-like immunoreactive endocrine cells, but an increase in the relative densities of endocrine cells containing cholecystokinin-8- and gastrin-like substances. There were, however, no significant differences in the number of endocrine cells that were immunoreactive to secretin, neuropeptide Y and peptide histidine-isoleucine antisera in the digestive tracts of either the infected or non-infected O. mykiss.     

Genetic diversity,population structure,and correlations between locally adapted zebu and taurine breeds in Brazil using SNP markers

Genetic diversity is one of the most important issues in studies on conservation of cattle breeds and endangered species. The objective of this study was to estimate the levels of genetic differentiation between locally adapted taurine (Bos taurus taurus) and zebu (Bos taurus indicus) breeds in Brazil, which were genotyped for more than 777,000 SNPs. The fixation index (F _ST), principal component analysis (PCA), and Bayesian clustering were estimated. The F _ST highlighted genetic differentiation between taurine and zebu breeds. The taurine lines, Caracu and Caracu Caldeano, had significant genetic differentiation (F _ST close to 5%) despite their recent selection for different uses (meat and milk). This genetic variability can be used for conservation of locally adapted animals, as well as for breeding programs on zebu breeds. Introgression of zebu in locally adapted breeds was identified, especially in Curraleiro Pé-Duro breed. The Gyr breed, however, had low breed purity at genomic level due to its very heterogeneous mixing pattern.     

Investigation of insecticidal activity of rye α-amylase inhibitor gene expressed in transgenic tobacco (Nicotiana tabacum) toward cotton boll weevil (Anthonomus grandis)

Innumerable proteinaceous α-amylase inhibitors have been isolated and identified from different plant species. Among them, an α-amylase inhibitor gene with bioinsecticidal potential toward Anthonomus grandis (cotton boll weevil) was previously identified in rye seeds (Secale cereale). This cereal inhibitor was expressed in tobacco plants (Nicotiana tabacum) under control of phytohemaglutinin promoter by using Agrobacterium tumefasciens - mediated transformation. Presence of αBIII-rye gene and further protein expression were confirmed by PCR and Western blot analysis, respectively. Immunological assays indicated that the recombinant inhibitor was expressed in concentration range from 0.1% to 0.28% (w:w) of the total protein in tobacco seeds of R₀ plants. From 14 independent transformants, five plants with expression levels between 0.20% and 0.28% in seeds were in vitro assayed against A. grandis amylolytic enzymes causing clear inhibition. Moreover, bioassays using transgenic seed flour mixture for artificial diet produced 74% mortality in A. grandis first larval instar. These data suggest that rye inhibitor could be a promising biotechnological tool for produce transgenic cotton plants with an increased resistance to cotton boll weevil. Moreover, αBIII-rye gene should be considered a potential compound for a pyramiding strategy aiming to delay insect-resistance.     

Genetic parameters estimation in an Italian horse native breed to support the conversion from agricultural uses to riding purposes

Horses are nowadays mainly used for sport and leisure purposes, and several local breeds, traditionally used in agriculture, are exposed to the risk of extinction. The long-term survival of local horse breeds depends on strategies to both monitor their genetic diversity and to find their sustainable role in the equine market. Thus, several local horse breeds need to adapt their breeding objective to allow a modernization process. The Bardigiano is an example of such horse breeds; we, therefore, studied the existing evaluation protocol from a genetic standpoint to assess the protocol's suitability to convert the Bardigiano from an agricultural to a riding horse. To this end, we estimated genetic parameters for four conformation measurements, ten grading traits and 23 linear traits. For conformation measurements, the heritabilities ranged from 0.31 for cannon bone circumference to 0.63 for height at withers. For conformation and attitude grading traits, the highest heritability (0.34) was estimated for development and the lowest (0.09) for gaits. The heritabilities for linear traits ranged from 0.05 for the leg straightness to 0.32 for the coat colour. Genetic correlations between linear traits and corresponding grading traits varied considerably, ranging from −0.42 to 0.98. This study showed that the current evaluation protocol in the Bardigiano horse is appropriate for genetic evaluation. Genetic parameters estimation can, in turn, be used to develop novel breeding values to help this conversion. Our study paves the way to optimize the Bardigiano horse breeding programme, and it may help several other local horse breeds experiencing similar issues.