Molecular and phenotypic features of <i>Pseudomonas syringae</i> pv. <i>actinidiae</i> isolated during recent epidemics of bacterial canker on yellow kiwifruit (<i>Actinidia chinensis</i>) in central Italy

Pseudomonas syringae pv. actinidiae (Psa) was identified as the causal agent of severe epidemics of bacterial canker on Actinidia chinensis (yellow kiwifruit) in central Italy occurring during 2008–9. A total of 101 strains were obtained from infected leaves, twigs, branches and trunks of cvs Hort16A, Jin Tao and CK3. Outbreaks were also found on A. deliciosa cv. Hayward. A representative set of 21 strains were compared with other Psa strains isolated from previous outbreaks in Japan and Italy as well as with P. s. pv. syringae strains obtained from A. chinensis and with strains of genomospecies 8. Repetitive‐sequence PCR (rep‐PCR) typing using BOX and ERIC primer sets revealed that all Psa strains obtained during 2008–9 showed the same fingerprinting profile. This profile, however, was different from those of strains previously isolated in Japan and Italy. Multilocus sequence typing (MLST) of gapA, gltA, gyrB and rpoD revealed a higher genetic variability among the strains than rep‐PCR, with some of them showing the same sequence pattern although isolated from different areas, cultivars and years. None of the recently obtained strains possessed genes coding for phaseolotoxin or coronatine, and all had an effector protein, namely hopA1, differentiating them from the strains causing past outbreaks in Japan and Italy. All isolates were inhibited in vitro by copper‐based compounds, antibiotics, geraniol, citronellol and by a chitin‐based organic compound. The recent epidemics found in central Italy on yellow kiwifruit appear to have been caused by a different Psa population than those previously recorded in Japan, South Korea and Italy

Molecular characterization of <i>Erwinia amylovora</i> strains from different host plants through RFLP analysis and sequencing of <i>hrp</i>N and <i>dsp</i>A/E genes

A total of 73 Erwinia amylovora strains obtained from 13 Maloideae host species and from Rubus spp., and isolated from different geographic areas, were assessed using RFLP and DNA sequencing analysis of the 3′hrpN gene and/or of a fragment of 1341 bp of the dspA/E region. An Erwinia pyrifoliae strain, used as outgroup, was checked in the same way. For the three strains isolated from Rubus spp. and for one strain from Amelanchier sp., RFLP analysis of the hrpN gene using the RsaI enzyme yielded a PCR product 60 bp smaller than that of all the other strains. Sequence analysis of the gene revealed this was due to the absence of a 60 bp fragment in the noncoding region downstream of the gene. The strain PD 2915, isolated from Amelanchier sp. grown in Canada, showed five same‐sense substitutions and one missense substitution at position 868 of the hrpN gene, converting aspartic acid into asparagine. Also, restriction analysis of a fragment of 613 bp of the dspA/E region with CfoI revealed an RFLP pattern suitable for differentiating the E. amylovora strains isolated from Rubus spp. and Amelanchier sp. from all the others. In the dspA/E coding region, the four strains showed 13–14 missense point mutations, in some cases yielding drastic amino acid substitutions. In addition, partial sequencing of the dspA/E region of PD 2915 from Amelanchier sp. indicated a higher similarity to E. amylovora strains isolated from Rubus spp. than towards strains from other Maloideae hosts. The E. pyrifoliae strain showed 23 single nucleotide substitutions along the hrpN gene and 88% of nucleotide identity with E. amylovora strains in the portion of dspA/E region. Artificial inoculations on immature pear fruits and young shoots of Maloideae and Ruboideae showed a restricted pathogenicity for the strains from Rubus and Amelanchier, with the latter inciting blight symptoms only on Amelanchier

Oxidative damage and cell-programmed death induced in Zea mays L. by allelochemical stress

The allelochemical stress on Zea mays was analyzed by using walnut husk washing waters (WHWW), a by-product of Juglans regia post-harvest process, which possesses strong allelopathic potential and phytotoxic effects. Oxidative damage and cell-programmed death were induced by WHWW in roots of maize seedlings. Treatment induced ROS burst, with excess of H2O2 content. Enzymatic activities of catalase were strongly increased during the first hours of exposure. The excess in malonildialdehyde following exposure to WHWW confirmed that oxidative stress severely damaged maize roots. Membrane alteration caused a decrease in NADPH oxidase activity along with DNA damage as confirmed by DNA laddering. The DNA instability was also assessed through sequence-related amplified polymorphism assay, thus suggesting the danger of walnut processing by-product and focusing the attention on the necessity of an efficient treatment of WHWW

A general model of dioxin contamination in breast milk: results from a study on 94 women from the Caserta and Naples areas in Italy.

BackgroundThe Caserta and Naples areas in Campania Region experience heavy environmental contamination due to illegal waste disposal and burns, thus representing a valuable setting to develop a general model of human contamination with dioxins (PCDDs-PCDFs) and dioxin-like-PCBs (dl-PCBs).Methods94 breastfeeding women (aged 19-32 years; mean age 27.9 ± 3.0) were recruited to determine concentrations of PCDDs-PCDFs and dl-PCBs in their milk. Individual milk samples were collected and analyzed according to standard international procedures. A generalized linear model was used to test potential predictors of pollutant concentration in breast milk: age, exposure to waste fires, cigarette smoking, diet, and residence in high/low risk area (defined at high/low environmental pressure by a specific 2007 WHO report). A Structural Equation Model (SEM) analysis was carried out by taking into account PCDDs-PCDFs and dl-PCBs as endogenous variables and age, waste fires, risk area and smoking as exogenous variables.ResultsAll milk samples were contaminated by PCDDs-PCDFs (8.6 pg WHO-TEQ/98g fat ± 2.7; range 3.8-19) and dl-PCBs (8.0 pg WHO-TEQ/98g fat ± 3.7; range 2.5-24), with their concentrations being associated with age and exposure to waste fires (p &lt; 0.01). Exposure to fires resulted in larger increases of dioxins concentrations in people living in low risk areas than those from high risk areas (p &lt; 0.01).ConclusionsA diffuse human exposure to persistent organic pollutants was observed in the Caserta and Naples areas. Dioxins concentration in women living in areas classified at low environmental pressure in 2007 WHO report was significantly influenced by exposure to burns

List of New Names of Plant Pathogenic Bacteria (2008-2010)

In 2010 the International Society of Plant Pathology Committee on the Taxonomy of Plant Pathogenic Bacteria published the Comprehensive List of Names of Plant Pathogenic Bacteria, 1980-2007 to provide an authoritative register of names of plant pathogens. In this manuscript we update the list of names by cataloguing names published from 2008 to 2010. We provide those names that have been validly and effectively published in this time frame, the proposed names that we judged to be invalid and names published earlier that did not make the previous lists. We also discuss problems that arise in the naming of strains that fall into the status Candidatus and nomenclatural problems in the genus Xanthomonas

List of New Names of Plant Pathogenic Bacteria (2011-2012)

The International Society of Plant Pathology Committee on the Taxonomy of Plant Pathogenic Bacteria has responsibility to evaluate the names of newly proposed pathovars for adherence to the International Standards for Naming Pathovars of Phytopathogenic Bacteria. Currently, the Comprehensive List of Names and the List of New Names of Plant Pathogenic Bacteria provide the authoritative register of names of bacterial plant pathogens. In this manuscript we up-date the list of names by cataloguing and evaluating names of plant pathogenic bacteria published in 2011 and 2012. We provide those names that have been validly and effectively published in this time frame, the proposed names that we judged to be invalid, and names published earlier that did not make the previous lists

Evaluation of the efficiency of a conventional PCR protocol for the diagnosis of bacterial spot disease caused by Xanthomonas arboricola pv. pruni in stone fruits and almond

Xanthomonas arboricola pv. pruni (Xap), the causal agent of bacterial spot disease of stone fruits and almond, has a quarantine status for the European Union and the European and Mediterranean Plant Protection Organization. The symptoms in the diverse hosts show some differences and, although being quite typical, could be confused with those of some fungal diseases or other biotic or abiotic causes. Consequently, an accurate molecular diagnosis method is required for a rapid identification of the pathogen in samples of imported plants, from nurseries, orchards, etc. A protocol for conventional PCR designed by Pagani (2004) has been the only molecular analytic tool available for several years. It has been optimised for improving its specificity and sensitivity, and the results of its evaluation in 316 bacterial spot-like symptomatic samples of almond, apricot, cherry, Japanese plum and peach, compared with those of isolation and real-time PCR, are reported. The optimised PCR protocol showed specificity for a collection of Xap strains tested. Few non-desired reactions were obtained with some other xanthomonads which have not been reported from Prunus species. Sensitivity thresholds ranged from 102 to 105 CFU ml-1, depending on the hosts and type of plant material. This conventional PCR assay proved to be an excellent candidate for a rapid screening and presumptive diagnosis in cases where real-time PCR equipment is not available

1H-NMR metabolite fingerprinting analysis reveals a disease biomarker and a field treatment response in xylella fastidiosa subsp. Pauca-infected olive trees

Xylella fastidiosa subsp. pauca is a xylem-limited bacterial phytopathogen currently found associated on many hectares with the “olive quick decline syndrome” in the Apulia region (Southern Italy), and the cultivars Ogliarola salentina and Cellina di Nardò result in being particularly sensitive to the disease. In order to find compounds showing the capability of reducing the population cell density of the pathogen within the leaves, we tested, in some olive orchards naturally-infected by the bacterium, a zinc-copper-citric acid biocomplex, namely Dentamet®, by spraying it to the crown, once per month, during spring and summer. The occurrence of the pathogen in the four olive orchards chosen for the trial was molecularly assessed. A 1H NMR metabolomic approach, in conjunction with a multivariate statistical analysis, was applied to investigate the metabolic pattern of both infected and treated adult olive cultivars, Ogliarola salentina and Cellina di Nardò trees, in two sampling periods, performed during the first year of the trial. For both cultivars and sampling periods, the orthogonal partial least squares discriminant analysis (OPLS-DA) gave good models of separation according to the treatment application. In both cultivars, some metabolites such as quinic acid, the aldehydic form of oleoeuropein, ligstroside and phenolic compounds, were consistently found as discriminative for the untreated olive trees in comparison with the Dentamet®-treated trees. Quinic acid, a precursor of lignin, was confirmed as a disease biomarker for the olive trees infected by X. fastidiosa subsp. pauca. When treated with Dentamet®, the two cultivars showed a distinct response. A consistent increase in malic acid was observed for the Ogliarola salentina trees, whereas in the Cellina di Nardò trees the treatments attenuate the metabolic response to the infection. To note that in Cellina di Nardò trees at the first sampling, an increase in γ-aminobutyric acid (GABA) was observed. This study highlights how the infection incited by X. fastidiosa subsp. pauca strongly modifies the overall metabolism of olive trees, and how a zinc-copper-citric acid biocomplex can induce an early re-programming of the metabolic pathways in the infected trees

Progress towards sustainable control of xylella fastidiosa subsp. Pauca in olive groves of salento (apulia, italy)

Xylella fastidiosa subsp. pauca is the causal agent of “olive quick decline syndrome” in Salento (Apulia, Italy). On April 2015, we started interdisciplinary studies to provide a sustainable control strategy for this pathogen that threatens the multi-millennial olive agroecosystem of Salento. Confocal laser scanning microscopy and fluorescence quantification showed that a zinc-copper-citric acid biocomplex—Dentamet® —reached the olive xylem tissue either after the spraying of the canopy or injection into the trunk, demonstrating its effective systemicity. The biocomplex showed in vitro bactericidal activity towards all X. fastidiosa subspecies. A mid-term evaluation of the control strategy performed in some olive groves of Salento indicated that this biocomplex significantly reduced both the symptoms and X. f. subsp. pauca cell concentration within the leaves of the local cultivars Ogliarola salentina and Cellina di Nardò. The treated trees started again to yield. A1 H-NMR metabolomic approach revealed, upon the treatments, a consistent increase in malic acid and γ-aminobutyrate for Ogliarola salentina and Cellina di Nardò trees, respectively. A novel endotherapy technique allowed injection of Dentamet® at low pressure directly into the vascular system of the tree and is currently under study for the promotion of resprouting in severely attacked trees. There are currently more than 700 ha of olive groves in Salento where this strategy is being applied to control X. f. subsp. pauca. These results collectively demonstrate an efficient, simple, low-cost, and environmentally sustainable strategy to control this pathogen in Salento

Impact of a probiotic diet on well-being of healthy senior: THE PROBIOSENIOR PROJECT

Aims: The aim of this work was to assess the effects of a probiotic diet on well-being of healthy seniors living in boarding and private homes in Marche Region, Italy. In particular, we focused on the modulation of high-sensitivity C-reactive protein (HsCRP), intestinal microbiota and short-chain fatty acids (SCFAs). Methods and Results: Ninety-seven healthy seniors took part in a double-blind, placebo-controlled feeding study (59 fed probiotics, 38 fed placebo) for 6&nbsp;months. Each volunteer ingested daily one food product or a dietary supplement enriched with Synbio® blend (Synbiotec Srl, Camerino, Italy) or the placebo (control group). Blood and faecal samples were collected before and at the end of the intervention period to perform biochemical and microbiological analyses. The serum HsCRP difference value after 6&nbsp;months of treatment was significantly higher in the probiotic group than placebo (p &lt; 0.05). After the intervention, a significant increase in faecal lactobacilli and a bifidobacteria increase in more participants were observed in the probiotic group. The 16S NGS analysis on the probiotic group showed a decreasing trend of Proteobacteria at the end of the treatment and conversely, an increasing trend of Actinobacteria and Verrucomicrobia phyla, to which the increase of Akkermansiaceae and Bifidobacteriaceae contributes at the family level. Finally, total short-chain fatty acids (SCFAs) and butyric acid were significantly higher in the probiotic group at the end of the treatment respect to the beginning. Conclusions: Overall, this study emphasizes the beneficial anti-inflammageing effect of a prolonged diet based on functional foods enriched with Synbio® through the modulation of the intestinal microbiota and the consequent increase in the SCFA production. Significance and Impact of the Study: Synbio® integration in elderly daily diet may be a preventive strategy to support healthy ageing