Salmonella enterica Serovar Typhimurium Exploits Inflammation to Modify Swine Intestinal Microbiota.

Salmonella enterica serovar Typhimurium is an important zoonotic gastrointestinal pathogen responsible for foodborne disease worldwide. It is a successful enteric pathogen because it has developed virulence strategies allowing it to survive in a highly inflamed intestinal environment exploiting inflammation to overcome colonization resistance provided by intestinal microbiota. In this study, we used piglets featuring an intact microbiota, which naturally develop gastroenteritis, as model for salmonellosis.

Salmonella Typhimurium exploits inflammation to its own advantage in piglets.

Salmonella Typhimurium (S. Typhimurium) is responsible for foodborne zoonotic infections that, in humans, induce self-limiting gastroenteritis. The aim of this study was to evaluate whether the wild-type strain S.

Attenuated mutant strain of Salmonella Typhimurium lacking the ZnuABC transporter contrasts tumor growth promoting anti-cancer immune response.

Salmonella Typhimurium has been shown to be highly effective as antitumor agent. The aim of this study was to investigate the tumor targeting efficacy and the mechanism of action of a specific attenuated mutant strain of Salmonella Typhimurium (STM) devoid of the whole operon coding for the high-affinity zinc transporter ZnuABC, which is required for bacterial growth in environments poor in zinc and for conferring full virulence to different Gram-negative pathogens.We showed that STM is able to penetrate and replicate into tumor cells in in vitro and in vivo models.

Protective role of antibodies induced by Brucella melitensis B115 against B. melitensis and Brucella abortus infections in mice.

It has been demonstrated that antibodies specific for O-PS antigen of Brucella smooth strains are involved in the protective immunity of brucellosis. Since the rough strain Brucella melitensis B115 was able to protect mice against wild Brucella strains brucellosis despite the lack of anti-OPS antibodies, in this study we evaluated the biological significance of antibodies induced by this strain, directed to antigens other than O-PS, passively tranferred to untreated mice prior to infection with Brucella abortus 2308 and B. melitensis 16M virulent strains.

B. melitensis rough strain B115 is protective against heterologous Brucella spp. infections.

Brucellosis is one of the most serious zoonoses all over the world, with B. melitensis, B. abortus and B.

CD4+CD25+ T regulatory cells limit effector T cells and favor the progression of brucellosis in BALB/c mice.

Brucellosis is one of the most common bacterial zoonoses worldwide. Infection is usually chronic and sometimes lifelong. Different mechanisms can be postulated as to the basis for the induction of the chronic status of brucellosis, but a comprehensive knowledge is still lacking.

Involvement of nitric oxide in the control of a mouse model of Campylobacter jejuni infection.

Campylobacter jejuni is an important enteropathogenic bacterium, causing food-borne gastroenteritis in both industrialized and developing countries. Campylobacter jejuni is a ubiquitous microorganism and, in endemic areas the highest incidence of infections is found in children. This finding suggests that hosts, after a first contact with the pathogen, are able to induce a protective immune response against subsequent exposures.

Attenuated Salmonella enterica serovar Typhimurium lacking the ZnuABC transporter confers immune-based protection against challenge infections in mice.

Salmonella enterica has long been recognised as an important zoonotic pathogen of economic significance, both in animals and humans. We have recently shown that inactivation of the ZnuABC high affinity zinc transporter significantly affects the pathogenicity of S. enterica, likely due to zinc shortage in the eukaryotic tissues.

High-affinity Zn2+ uptake system ZnuABC is required for bacterial zinc homeostasis in intracellular environments and contributes to the virulence of Salmonella enterica.

To investigate the relevance of zinc in host-pathogen interactions, we have constructed Salmonella enterica mutant strains in which the znuA gene, which encodes the periplasmic component of the ZnuABC high-affinity Zn2+ transporter, was deleted. This mutation does not alter the ability of Salmonella to grow in rich media but drastically reduces its ability to multiply in media deprived of zinc. In agreement with this phenotype, ZnuA accumulates only in bacteria cultivated in environments poor in zinc.

Brucella abortus RB51 induces protection in mice orally infected with the virulent strain B. abortus 2308.

Brucellae are gram-negative, facultative intracellular bacteria which are one of the most common causes of abortion in animals. In addition, they are the source of a severe zoonosis. In this trial, we evaluated the effect of oral inoculation of Brucella abortus RB51 in mice against a challenge infection with B.

Effect of exogenous interleukin-18 (IL-18) and IL-12 in the course of Brucella abortus 2308 infection in mice.

In this study we demonstrated that combined inoculation of interleukin-12 (IL-12) and IL-18 reduced the number of bacteria in the spleens of mice infected with Brucella abortus 2308 and that the effect of the treatment was mediated by an increased capability of spleen cells to produce gamma interferon at the early phase of infection.