Detection of a Phytoplasma Associated with Grapevine Flavescence dorée in Clematis vitalba

About 40 different species of wild herbaceous and woody plants were collected in underbrush close to a vineyard where Flavescence dorée (FD) has been reported for several years. Polymerase chain reaction assays were carried out using DNA extracted from leaves of each species for the detection of the presence of phytoplasmas. Only samples of Clematis vitalba were found to be infected with phytoplasmas. Restriction fragment length polymorphism and sequencing data of the 16S ribosomal RNA gene and of a non-ribosomal DNA fragment FD9 revealed that the phytoplasma isolate was identical to that causing FD in the nearby vineyard. The isolate identified in the clematis is the same as the FD-C phytoplasma found in grapevine in north-east Italy.     

Comparison of the sequences of the D3 expansion of the 26S ribosomal genes reveals different degrees of heterogeneity in different populations and species of <Emphasis Type="Italic">Pratylenchus</Emphasis> from the Mediterranean region

Plant parasitic nematodes belonging to the genus Pratylenchus, also known as root lesion nematodes, cause serious economic damage to different crop plants. In order to explore genetic structures in different isolates, we investigated several P. thornei, P. neglectus and P. penetrans populations of different geographic origins. The analysis at the species level was also extended to P. penetrans, P. pinguicaudatus, P. vulnus and P. mediterraneus. Sequence analysis of a specific portion of DNA was carried out. In particular, the sequences of the D3 region of the 26S gene were obtained and compared with similar sequences available in databases. The results support the hypothesis that P. penetrans may represent a species complex, while in P. neglectus the intra-species heterogeneity observed is due to intra-individual variability. Furthermore, the specific conservation of some nucleotides in different P. thornei populations indicates their fixation in the rDNA repeats in this species. The presence of these nucleotides, the molecular signature of P. thornei, may assist in determining the nature of nematode infections.     

Characterization of cell wall associated proteins of a Staphylococcus aureus isolated from bovine mastitis case by a proteomic approach

Staphylococcus aureus causes different pathologies in humans and animals. In particular, it is involved in intramammary infections in cows, causing economic losses and milk-safety problems. Although it is well-known that surface components (proteins and capsular polysaccharides) and exotoxins are virulence factors involved in the pathogenesis of bovine mastitis, less is known about the precise biochemical identity of such molecules. Therefore, mapping of surface proteins using specific disease- and environment-isolates provides a benchmark for strain comparison of pathogens with different pathogenic characteristics and antibiotic resistance mechanism and can aid in defining specific vaccine and therapeutic targets. In this study, we used a proteomic approach on protein extracts of lysostaphin-treated S. aureus in isotonic conditions, to produce a reproducible and well resolved 2-D electrophoresis (2-DE) reference map of surface associated proteins of isolated S. aureus from a case of bovine mastitis. The most abundant protein components were identified by Matrix assisted laser desorption ionisation-time of flight (MALDI-TOF) mass spectrometry.     

Impact of the botanical insecticide Neem Azal on survival and reproduction of the biting louse Damalinia limbata on angora goats

Secondary metabolites present in the neem tree (Azadirachta indica A. Juss, Meliaceae), exhibit a wide range of biological activities in insects. However, few studies have been undertaken to assess the potential of neem products as insecticides for the control of ectoparasites of domestic animals. This study was undertaken to estimate the efficacy of Neem Azal, an azadirachtin-rich extract of neem seeds, in controlling Damalinia limbata (Phthiraptera) louse infestation of angora goats. The study was conducted on a fibre animal farm situated in Central Italy. Groups of 11-12 goats were treated with Neem Azal at an azadirachtin concentration of 650ppm or 125ppm, with Neguvon or were left untreated. Their louse burden was assessed fortnightly to monthly for 22 weeks. A reduction in louse densities of 76-96% was observed from week 2 to week 18 after treatment with the neem solution containing azadirachtin at a concentration of 650ppm. At the lower test concentration (125ppm) a reduction of 60-92% could be recorded from week 2 to week 14. Neem Azal was found to reduce the survival of both adult and nymph stages of D. limbata and to interfere with oviposition and oogenesis of female lice. A decrease in oviposition was observed in neem exposed female lice and the examination of their ovaries revealed morphological alterations in both vitellogenic and previtellogenic ovarioles at the follicular and germinal level. Since neem compounds target different life stages and physiological processes of D. limbata, the development of insecticide resistance by biting lice exposed to neem-based insecticides appears unlikely. For this reason and for its prolonged activity, which in principle allows angora goats to be protected for a large part of the mohair production cycle, neem-based insecticides may have a potential interest for mohair producing breeders.     

Skin biopsies predict acute graft-versus-host disease after small bowel transplantation in pigs

Intestinal transplantation is being increasingly performed to treat patients with irreversible intestinal failure. The major cause of intestinal graft failure is graft-versus-host disease (GVHD) that represents a life-threatening complication after small bowel transplantation (Itx). The purpose of this study was to assess the diagnostic and prognostic value of skin biopsy histological changes for acute GVHD after Itx in pigs. Thirty-four Large White pigs were divided into three groups: Group 1 with Itx only, Group 2 with Itx and donor bone marrow infusion (Itx BM) and Group 3 (control group - before the operation). Animals received tacrolimus-based immunosuppression from day 0 to day 30 postoperatively. Skin and small bowel biopsies were histologically assessed, analysed and classified from grade 1 to 4 on postoperative days 15, 30, 45 and 60. There was a strong correlation between the histological grading values of skin biopsy changes and the histological grading values of small bowel biopsy changes (Kendall's tau_b is 0.855 for the Itx group and 0.730 for the Itx BM group). The significant correlation found between skin and small bowel histological changes suggests the prognostic value of skin biopsies after Itx. In conclusion, our findings emphasise the diagnostic and prognostic value of skin biopsy analysis for acute GVHD after Itx.     

Determination of origin of Atlantic salmon (Salmo salar): the use of multiprobe and multielement isotopic analyses in combination with fatty acid composition to assess wild or farmed origin

Variability within the stable isotope ratios in various lipidic fractions and the fatty acid composition of muscle oil has been analyzed for a large sample (171 fish) of wild and farmed Atlantic salmon ( Salmo salar) from 32 origins within Europe, North America, and Tasmania. Sampling was extended over all seasons in 2 consecutive years and included fish raised by different practices, in order to maximize the range of variation present. It is shown that two readily measured parameters, delta 15N measured on choline and delta18 O measured on total oil, can be successfully used to discriminate between fish of authentic wild and farmed origin. However, the certainty of identification of mislabeling in market-derived fish is strengthened by including the percentage of linoleic acid C18:2n-6 in the lipidic fraction. Thus, several apparent misidentifications were found. The combination of these three analytical parameters and the size of the database generated makes the method practical for implementation in official laboratories as a tool of labeling verification.     

Bioaccumulation potential of dietary arsenic, cadmium, lead, mercury, and selenium in organs and tissues of rainbow trout (Oncorhyncus mykiss) as a function of fish growth

The distribution and potential bioaccumulation of dietary arsenic, cadmium, lead, mercury, and selenium in organs and tissues of rainbow trout (Oncorhyncus mykiss Walbaum, 1792), a major aquaculture species, was studied in relation to fish growth over a period of >3 years. Fish were reared under normal farming conditions, that is, fed a standard fish food and exposed to negligible levels of waterborne trace elements. The age-related variations in the content of each trace element in gills, kidney, liver, muscle, and skin were studied through nonparametric regression analysis. A buildup of all elements in all tissues and organs was observed, but due to dilution with growth, the concentrations did not increase, except in a few cases such as cadmium and mercury in liver and kidney. In muscle tissue, the concentrations of mercury, lead, and selenium did not alter significantly with growth, whereas cadmium increased but remained at exceedingly low levels. The concentration of arsenic in muscle tissue peaked at 14 months and then decreased in adult specimens. Arsenic speciation by high-performance liquid chromatography--inductively coupled plasma mass spectrometry revealed that arsenic in muscle was almost exclusively present in the form of nontoxic arsenobetaine. Application of a mercury mass balance model gave predicted concentrations in agreement with measured ones and showed that in farmed rainbow trout the ratio of mercury concentrations in feed and in fish is about 1:1. Therefore, rainbow trout does not approach the limits established for human consumption even when reared with feed at the maximum permitted levels. These findings highlight the low bioaccumulation potential of toxic trace elements such as cadmium, lead, and mercury in rainbow trout following dietary exposure. On the other hand, selenium concentrations in muscle (about 0.2 microg g (-1) of fresh weight) show that rainbow trout may be a good source of this essential element.     

Ochratoxin a contamination in italian wine samples and evaluation of the exposure in the italian population

The scope of this study was to evaluate the exposure of the Italian population to ochratoxin A (OTA) attributable to wine consumption. With this aim 1166 wine samples (773 red wines, 290 white, 75 rose, and 28 dessert wines), collected in 19 different Italian regions and mostly produced between 1988 and 2004, were analyzed for OTA content. The obtained results are reported by year of harvest, geographical area of production, and type of wine. Red wine showed the highest maximum level of contamination (7.50 ng/mL), even though rose wines were characterized by a higher mean value (0.01 ng/mL). A gradually increasing mean concentration was also observed from the north (0.05 ng/mL) to south of Italy (0.54 ng/mL). Exposure calculations, performed using two different consumption databases, indicate a daily intake for consumer only of 0.59 up to 1.24 ng/(kg of b.w.)/day and of 0.33 up to 0.90 ng/(kg of b.w.)/day for the total population. Even in the worst case, corresponding to the calculation of the intake for consumers only in southern Italy and Islands and considering the mean consumption data increased by 1 standard deviation, a quite low exposure (1.68 ng/(kg of b.w.)/day, accounting for 9.8% of TDI) was obtained. Considering the overall OTA dietary exposure, obtained exposure rates indicate that wine did not pose a risk to the Italian population health.