An update on pathogenesis and control of Salmonella infections in pigs

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Application of the DIVA principle to Salmonella Typhimurium vaccines in pigs avoids interference with serosurveillance programmes

Salmonellosis is one of the most important bacterial zoonotic diseases in humans and Salmonella infections are often linked with the consumption of contaminated pork. In order to reduce Salmonella Typhimurium infections in humans, minimization of the Salmonella intake into the food chain is important. Vaccination has been proposed to control Salmonella infections in pigs. However, pigs vaccinated with the current vaccines cannot be discriminated from infected pigs with the lipopolysaccharide (LPS) -based serological tests used in European serosurveillance programmes. We therefore examined which LPS encoding genes of Salmonella Typhimurium can be deleted to allow differentiation of infected and vaccinated pigs, without affecting the vaccine strain’s protective capacity. For this purpose, deletion mutants in Salmonella strain 112910a, used as vaccine strain, were constructed in the LPS encoding genes: ∆rfbA, ∆rfaL, ∆rfaJ, ∆rfaI, ∆rfaG and ∆rfaF. Inoculation of BALB/c mice with the parent strain, ∆rfaL, ∆rfbA or ∆rfaJ strains but not the ∆rfaG, ∆rfaF or ∆rfaI strains protected significantly against subsequent infection with the virulent Salmonella Typhimurium strain NCTC12023. Immunization of piglets with the ∆rfaJ or ∆rfaL mutants resulted in the induction of a serological response lacking detectable antibodies against LPS. This allowed a differentiation between sera from pigs immunized with the ∆rfaJ or ∆rfaL strains and sera from pigs infected with their isogenic wild type strain

Prevalence of respiratory pathogens in nasal swabs from horses with acute respiratory disease in Belgium

Contagious respiratory infections are an important cause of respiratory disease in horses, resulting in impaired pulmonary function, poor performance and sometimes severe illness. Although bacterial infections are often suspected to be involved, viruses are frequently overlooked and are an underestimated cause of respiratory disease outbreaks in horses. In this study, nasal swabs of 103 horses with acute symptoms of respiratory disease were analyzed for the presence of 13 different respiratory pathogens. Gamma herpesviruses were the most commonly detected, with 60% of the samples being positive, followed by streptococcus equi subsp. zooepidemicus infection (30%). Rhinovirus B, streptococcus equi subsp. equi, adenovirus 1 and EHV-4 were more rarely detected. Further research is necessary to correctly interpret the importance of gamma herpesviruses in horses, for example by screening a healthy control population. National surveillance of respiratory viruses in horses by PCR analysis on nasal swabs might be a useful, early warning system for viral epidemics

Processes of internationalization that fit emerging markets in the hotel sector : the case of Pestana Group in Brazil

The service sector has, in the last decades, increased considerably its importance in the world’s economy. Within this sector, the hotel industry has accompanied this movement, and it’s now an important source of income and employment for various countries. This dissertation has the objective of better understanding how a hotel company from a developed country, internationalizes its activities into an emerging country, and implements its strategy while managing the turbulence of an emergent market. Thus, this work can contribute to the literature that regards the service sector industry, and that is still very insufficient. So an exploratory research was conducted, namely a case study, about the internationalization of the biggest Portuguese hotel company, the Pestana Group, into the Brazilian market, since they have successfully been there for the last 18 years. The data collected was retrieved through interviews made to the CEO and CDO of the Group. The findings show that in this kind of business, in order to have success, you have to consider the operational activity and the asset management one. There are no predefined modes of entry, being the crucial factors, the right timing and the right partnerships. Findings also showed that an emergent market poses challenges of various natures, and that they are the same ones faced by the manufacturing sector. In order to solve them, or at least mitigate some of them, you need to be ready for unexpected events, and be flexible to adapt your strategy and way of doing business.O sector dos serviços tem, nas últimas décadas, aumentando consideravelmente a sua importância na economia mundial. Dentro deste sector, a indústria hoteleira tem seguindo este movimento, e é neste momento uma importante fonte de rendimento e emprego para diversos países. Esta tese tem o objectivo de se perceber melhor como uma empresa hoteleira de um país desenvolvido, internacionaliza as suas actividades para um país emergente, e implementa a sua estratégia enquanto lida com a instabilidade de um mercado emergente. Deste modo, este trabalho pode contribuir para a literatura existente sobre o sector dos serviços, que ainda é bastante insuficiente. Então, uma pesquisa exploratória foi efectuada, nomeadamente um case study, sobre a internacionalização do maior grupo hoteleiro Português, o grupo Pestana, para o mercado Brasileiro, visto que estão lá com sucesso nos últimos 18 anos. A informação recolhida foi conseguida através de entrevistas feitas ao CEO e ao CDO do grupo. Os resultados mostram que neste tipo de negócio, para se ter sucesso, temos de considerar a actividade operacional e a gestão de activos. Não há modelos predefinidos de entrada, sendo que os factores cruciais a considerar, são o timing certo e as parcerias certas. Os resultados também mostram que um mercado emergente tem desafios de várias naturezas, e que esses são os mesmos encontrados no sector da indústria. De forma a resolvê-los, ou pelo menos atenua-los, tem que se estar preparados para eventos inesperados, e ser flexíveis para adaptar a sua estratégia e o modo de fazer negócios

Secure Data Provenance in Home Energy Monitoring Networks

Smart grid empowers home owners to efficiently manage their smart home appliances within a Home Area Network (HAN), by real time monitoring and fine-grained control. However, it offers the possibility for a malicious user to intrude into the HAN and deceive the smart metering system with fraudulent energy usage report. While most of the existing works have focused on how to prevent data tampering in HAN's communication channel, this paper looks into a relatively less studied security aspect namely data provenance. We propose a novel solution based on Shamir's secret sharing and threshold cryptography to guarantee that the reported energy usage is collected from the specific appliance as claimed at a particular location, and that it reflects the real consumption of the energy. A byproduct of the proposed security solution is a guarantee of data integrity. A prototype implementation is presented to demonstrate the feasibility and practicality of the proposed solution

Application of the DIVA principle to Salmonella Typhimurium vaccines in pigs avoids interference with serosurveillance programmes

Salmonellosis is one of the most important bacterial zoonotic diseases in humans and Salmonella infections are often linked with the consumption of contaminated pork. In order to reduce Salmonella Typhimurium infections in humans, minimization of the Salmonella intake into the food chain is important