Determinants of the population growth of the West Nile virus mosquito vector Culex pipiens in a repeatedly affected area in Italy

Background The recent spread of West Nile Virus in temperate countries has raised concern. Predicting the likelihood of transmission is crucial to ascertain the threat to Public and Veterinary Health. However, accurate models of West Nile Virus (WNV) expansion in Europe may be hampered by limited understanding of the population dynamics of their primary mosquito vectors and their response to environmental changes.<p></p> Methods We used data collected in north-eastern Italy (2009–2011) to analyze the determinants of the population growth rate of the primary WNV vector Culex pipiens. A series of alternative growth models were fitted to longitudinal data on mosquito abundance to evaluate the strength of evidence for regulation by intrinsic density-dependent and/or extrinsic environmental factors. Model-averaging algorithms were then used to estimate the relative importance of intrinsic and extrinsic variables in describing the variations of per-capita growth rates.<p></p> Results Results indicate a much greater contribution of density-dependence in regulating vector population growth rates than of any environmental factor on its own. Analysis of an average model of Cx. pipiens growth revealed that the most significant predictors of their population dynamics was the length of daylight, estimated population size and temperature conditions in the 15 day period prior to sampling. Other extrinsic variables (including measures of precipitation, number of rainy days, and humidity) had only a minor influence on Cx. pipiens growth rates.<p></p> Conclusions These results indicate the need to incorporate density dependence in combination with key environmental factors for robust prediction of Cx. pipiens population expansion and WNV transmission risk. We hypothesize that detailed analysis of the determinants of mosquito vector growth rate as conducted here can help identify when and where an increase in vector population size and associated WNV transmission risk should be expected.<p></p&gt

Toxic thermoresistant metabolites of Fusarium oxysporum are capable of inducing histopathological alterations in Wistar rats

The genus Fusarium is known to produce mycotoxins that cause fusariosis in plants, animals and humans. Mycotoxins are among the virulence factors of this genus. Metabolic extracts of Fusarium oxysporum, isolated from a patient with onychomycosis and sterilized by filtration or autoclave, were inoculated intradermally into Wistar rats at concentrations of 0.25, 0.5 and 1 µg/µL, and the effects on their tegument were observed at 24 and 72 hours. After histological procedures and staining by hematoxylineosin, the sections were studied for their inflammatory-reaction intensity and for evidence of injury and tissue distortion. Inflammatory reactions in the dermis and the subcutaneous tissue were observed at all concentrations of the inoculated extract tested. There was a significant influx of neutrophils, mastocytes and lymphocytes, as well as a large quantity of macrophages. Apoptotic bodies and hyperemic blood vessels were observed. This reaction was directly related to the extract concentration, and was most intense in animals that received the 1 mg/µL dose. The maximum peak was observed at 24 hours. The autoclaved metabolic extract produced the same effects as the untreated one, indicating the presence of heat-resistant metabolites. In conclusion, the metabolic extracts obtained from sterilized culture filtrates of F. oxysporum are capable of inducing an inflammatory response within 24 hours in the dermis and subcutaneous tissue of rats

the effects of control measures on the economic burden associated with epidemics of avian influenza in italy

In 1999, Italy experienced a devastating epidemic of high-pathogenicity avian influenza (HPAI) caused by an H7N1 virus subtype. After this epidemic, a ministerial decree was passed to implement control measures for low-pathogenicity avian influenza (LPAI) due to H5 and H7 subtypes. We investigated whether these control measures have decreased the public expenditure associated with epidemics of LPAI and HPAI by comparing the direct and consequential losses of the 1999 epidemic to the losses associated with successive epidemics. The estimated total economic burden of the epidemics was about euro650 million (euro217 million in direct losses and euro433 million in consequential losses). The 1999 epidemic accounted for most of these losses (euro507 million: euro112 million in direct losses and euro395 million in consequential losses), whereas the total economic burden for the 5 successive LPAI was euro143 million (euro105 million in direct losses and euro38 million in consequential losses). These results demonstrate that the implementation of a coordinated set of disease-control measures, which included both emergency and prophylactic vaccination, was able to reduce the overall costs associated with avian influenza epidemics. The results also show that the application of adequate LPAI control measures may limit the risk of emergence of an HPAI virus in an area with a high poultry density, allowing the complete disruption of the poultry market and its huge associated costs to be avoided

Terpenoids and norisoprenoids in Italian red wines

AIM Terpene compounds are associated with fl oral notes and are characteristic of aromatic grape varieties such as Muscat (Jackson,2008). They are generally considered to potentially contribute to the aroma of white wines. However, there is a growing interesttowards the potential contribution of terpene compounds to the aroma of red wines. The aim of this work was to investigate theoccurrence of diff erent terpenes in red wines from Italian varieties. METHODS For this study wines from 11 mono-varietal Italian redwines from 12 regions were used (19 Sangiovese, 11 Nebbiolo, 10 Aglianico, 11 Primitivo, 10 Raboso del Piave, 9 Cannonau, 11 Teroldego,3 Nerello, 9 Montepulciano, 7 Corvina). All samples were from vintage 2016 and none of them had been in contact with wood. A totalof 19 terpenes and 7 norisoprenoids were analysed by mean of SPME-GC-MS analysis using a DVB-CAR-PDMS fi ber. The wines werecollected in the framework of the activities of the D-Wines (Diversity of Italian wines) project. RESULTS Signifi cant diff erences amongvarieties were observed for basically all the compounds analyzed with the exception of limonene. Overall, the concentrations of thevarious terpenes remained in the same order of magnitude. However, some diff erences are noticeable between varieties. Corvina wascharacterized by higher level of linalool, followed by Aglianico, Nebbiolo, Primitivo and Sangiovese. Cyclic terpenoids appeared asgood varietal markers, for instances Montepulciano was characterized by 1,4-cineole and 1,8-cineole, whereas Sangiovese showedhigher levels of p-cymene, \u3b1-terpinene and 1,4-cineole. Higher terpinene-1-ol content was characteristic of Montepulciano and Rabosowines. Relatively high levels of the norisoprenoid \u3b2-damascenone were found in Cannonau up to 3.68 \u3bcg/L. CONCLUSIONS This studyprovide the fi rst survey of a large number of terpenoids and norisoprenoids in diff erent mono-varietal Italian red wines. The resultsshowed that a large number of terpenoids were present in Italian red wines with specifi c profi les related to the varieties