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If a threat cannot be avoided, the organism has two defense options: it can try to eliminate the threatening agent or boost physiological mechanisms to tolerate the challenge and its consequences. Both strategies can be (and usually are) used at the same time. Fighting an infection, for instance, requires mounting immune responses to control pathogen burden as well as physiologic adaptations to tolerate stress and damage. Thus, the two strategies are connected and interdependent. We are starting to understand how the regulation of host metabolic physiology during disease impacts both the ability to resist pathogens' burden and tolerate parenchymal tissue functional damage. Here, we review a number of recent publications that have begun to shed light on the physiological and immunological mechanisms that coordinate host defense and metabolic processes. In particular, we will cover the areas of energetic control, substrates utilization, and the regulatory signals that promote infectious disease tolerance.

Several studies report the presence of Helicobacter pylori (H. pylori) in seawater either free or attached to planktonic organism. After considering the role played by plankton in the food chain of most aquatic ecosystems and the possible role that seafood products can assume in the transmission of H. pylori to humans, the aim of this study was to assess the survival of H. pylori in artificially contaminated Mytilus galloprovincialis (M. galloprovincialis). A traditional culture method and a reverse transcriptase-PCR (RT-PCR) assay were employed to detect the mRNA of known virulence factor (VacA) which can be considered use a marker of bacterial viability. The obtained results clearly show that H. pylori is able to survive in artificially contaminated mussels for 6 days (2 days in a cultivable form and 4 days in a non-cultivable form).

The discovery of B cell subsets with regulatory properties, dependent on IL-10 production, has expanded our view on the mechanisms that control inflammation. Regulatory B cells acquire the ability to produce IL-10 in a stepwise process: first, they become IL-10 competent, a poised state in which B cells are sensitive to trigger signals but do not actually express the Il-10 gene; then, when exposed to appropriate stimuli, they start producing IL-10. Even if the existence of IL-10–competent B cells is now well established, it is not yet known how different immune cell types cross talk with B cells and affect IL-10–competent B cell differentiation and expansion. Mast cells (MCs) contribute to the differentiation and influence the effector functions of various immune cells, including B lymphocytes. In this study, we explored whether MCs could play a role in the expansion of IL-10–competent B cells and addressed the in vivo relevance of MC deficiency on the generation of these cells. We show that MCs can expand IL-10–competent B cells, but they do not directly induce IL-10 production; moreover, the absence of MCs negatively affects IL-10–competent B cell differentiation. Noteworthy, our findings reveal that the CD40L/CD40 axis plays a significant role in MC-driven expansion of IL-10–competent B cells in vitro and highlight the importance of MC CD40L signaling in the colon.

Slaughter by Jewish religious rite is the killing of an animal by cutting the trachea and oesophagus and major blood vessels using a very sharp blade. This operation is subject to strict rules laid down by religious authorities that characterize its sacredness. The aim of the study was to evaluate the specific criteria inherent in the Jewish religious rite, by analysing reject rates during the different phases. In this study, 52.4% of the carcasses failed to quality as Kosher, with 22.9% being rejected due to pulmonary lesions and only 3% for miscuts. The study also revealed legal vacuums in the field of labelling rules.

Verocytotoxin-producing Escherichia coli (VTEC) non-O157 serogroups are among the most important emerging food-borne pathogen groups. In particular, the O26 serogroup is able to cause a large spectrum of illnesses in humans which have a significant public health impact as they may range from haemorrhagic colitis (HC) to haemolytic uremic syndrome (HUS) and thrombotic thrombocytopenic purpura (TTP). It is known that VTEC organisms are associated with animal reservoirs, i.e. ruminants, and foods of animal origin, especially undercooked meat and raw milk, are often involved in outbreaks. In this study, 250 minced beef samples collected at retail outlets in southern Italy were tested for the presence of E. coli O26 and the isolates were characterized and studied for their antimicrobial resistance properties. Three minced beef samples (1.2%) tested positive for E. coli O26; one isolate per positive sample was characterized. One isolate harboured the genes encoding for virulence factors intimin (eaeA) and enterohaemolysin (hlyA), while none presented verocytotoxin-encoding genes (stx1 and stx2) and all were negative at the verotoxicity assay. All the isolates showed resistance properties to at least four antimicrobial agents tested and two were multi-drug resistant (MDR). Although no verocytotoxin-encoding genes were found in the isolates, the presence of potentially pathogenic E. coli O26 strains in minced beef points to the need for proper hygiene during meat production to reduce the risk of food-borne illnesses and transmission of MDR organisms via foods to humans. This paper is the first report on the presence and characterization of E. coli O26 in minced beef marketed in Italy.

Helicobacter pylori (H. pylori) is a very important bacterial pathogen of humans which may cause gastrointestinal illnesses ranging from gastric and duodenal ulcers to neoplastic diseases such as MALToma and gastric cancer. Transmission via contaminated food is still uncertain but several authors believe this can realistically occur and milk may act as a vehicle of infection. This paper reports the results of H. pylori survival trials in pasteurized and ultrahigh temperature (UHT) milks artificially contaminated and aerobically stored at 4 degrees C. The results obtained showed that the four strains used in this study (H. pylori nat 18-19-20 and H. pylori ATCC 43504), had a progressive reduction in bacterial load with a median survival of 9 days in pasteurized milk and 12 days in UHT milk, with approximate average of initial inoculum of 10(5) and 10(6)cfu/ml, respectively. These findings are very important to clarify the route of transmission of H. pylori to humans via food and for implementation of a correct risk analysis for food safety purposes.

Staphylococcus aureus is considered to be one of the leading causes of food-borne illnesses. Milk, dairy products and meats are often contaminated with enterotoxigenic strains of this bacterium. Foodstuff contamination may occur directly from infected food-producing animals or may result from poor hygiene during production processes, or the retail and storage of foods, since humans may carry the microorganism. The number of S. aureus strains that exhibits antimicrobial-resistance properties has increased, together with the potential risk of transmitting the same properties to the human microflora via foods or inducing infections hard to be treated. This paper reports the results of a 3-year survey (2003-2005) on the occurrence of S. aureus in meat and dairy products. Of 1634 samples examined, 209 (12.8%) were contaminated with S. aureus. A total of 125 enterotoxigenic S. aureus strains were biotyped and their antimicrobial resistance pattern tested. Most of the isolated strains produced SED (33.6%), followed by SEA (18.4%), SEC (15.2%), SEB (6.4%) and belonged mainly to the Human ecovar (50.4%), followed by Ovine (23.2%), Non-Host-Specific (17.6%), Bovine (7.2%) and Poultry-like (1.6%) ecovars. Finally, the 68.8% analysed strains showed antimicrobial resistance properties at least at one of antibiotics tested. Human biotype showed antimicrobial resistance at more than one antibiotic than the other biotypes (p

Many immunological processes are contextually controlled by complex interactions among different cell types. Several studies have shown that B cells produce the immune regulatory cytokine IL-10 in response to different external stimuli but also to immune-mediated signals. Endogenous signals that derive from the cross talk between B lymphocytes and other cells of the immune system can affect IL-10 production by B cells in both physiological and pathological conditions. With the aim to provide a guide for the study of how partner cells can induce IL-10-producing B cells, here we describe the protocols to investigate IL-10 production at a single cell level in a dendritic cell-B cell coculture in vitro system. These methods are a proof of concept that can be easily extrapolated and adapted to the study of the interaction between B cells and other immune cell types.

The adaptive immune system has developed several highly effective mechanisms in order to avoid excessive or unwanted reactions and promote resolution of immune activation. An emerging, significant body of evidence indicates that B cells can actively modulate immune responses by mechanisms that do not directly involve the production of antibodies. B cells appear to have the capacity to both induce and suppress immune effector mechanisms and they exert these functions both by contact-dependent interactions and through the secretion of cytokines. In this review we will focus on the regulatory suppressive function of several recently described B cell populations, functionally defined "regulatory B cells" or Breg cells. We will first outline the evidence that has led to their identification and then we will summarize current hypotheses on their ontogeny and possible lineage relationship.

STATs are a group of transcription factors that mediate actions of a variety of peptide hormones and cytokines within target cells (for example, prolactin and growth hormone). Therefore, STAT5A gene is a candidate marker for quantitative traits in farm animals with respect to milk production traits. In this study the STAT5A/AvaI polymorphism was investigated with PCR-RFLP in a sample of 233 Italian Brown cattle. This polymorphism is localized in the coding region of the bovine STAT5A gene. It is a substitution C→T at position 6853 within exon 7. All three possible genotypes for the C/T polymorphism were identified. The overall frequencies of alleles C and T were 0·83 and 0·17 respectively; the Hardy-Weinberg equilibrium was verified. In order to study the relationship between STAT5A/AvaI polymorphism and milk performance traits, the data for a 305-d milk production that included milk yield, protein and fat yield, fat and protein percentage were used. Significant differences between the two genotypes were found in yields of milk, fat and protein and protein percentage (Pv. 5149·54 kg). Protein content was higher in milk from CC compared with CT genotypes (3·40 v. 3·21%). No significant difference was found in fat content. Owing to the low number of TT cows in the studied population, this genotype was not included in the statistical analysis; in fact the number of TT cows was not enough to provide an accurate statistical analysis. Although more studies are needed to better clarify the role of this SNP on production traits, STAT5A/AvaI polymorphism appears to be a promising indirect marker to improve milk production traits in cattle.

Helicobacter pylori (Hp) is an organism commonly present worldwide in the human population, sometimes causing serious illnesses such as duodenal and gastric ulcers, adenocarcinoma of the stomach, and low-grade B-cell mucosa-associated lymphoid tissue lymphoma of the stomach. This article describes a multiplex-touchdown PCR method for the identification and genotyping (vacA-s1/m1, sl/m2, and s2/m2-and cagA genes) of Hp directly from sheep milk artificially contaminated with Hp strains from human gastric biopsies and with Hp ATCC 43504. The strains from humans carried sl/m2 cagA+ and s2/m2 cagA allelic combinations, while the ATCC strains carried an sl/ml cagA+ allelic combination. The technique showed a sensitivity of 15 CFU/ml for species identification and of 1,500 CFU/ml for the detection of genes encoding for VacA and CagA. It has proven to be specific and rapid, and the authors suggest that it be used as a rapid screening method to ensure that sheep milk is uncontaminated with this organism.

CD40 is a member of the growing tumor necrosis factor receptor family that has been shown to play important roles in T cell-mediated B lymphocyte activation. Ligation of B cell CD40 by CD154, mainly expressed on activated T cells, stimulates B cell proliferation, differentiation, isotype switching, up-regulation of surface molecules contributing to antigen presentation, development of the germinal center, and the humoral memory response. In this study we demonstrate that the redox factor APE/Ref-1 acts as a key signaling intermediate in response to CD40-mediated B cell activation. The transcription factors Pax5a or BSAP (B cell lineage-specific activator protein) and EBF (early B cell factor) are constitutively expressed in spleen B cells and CD40 cross-linking induces increases in Pax5a and EBF binding activity compared with nonstimulated B cells. We show that upon CD40 antibody-mediated cross-linking, APE/Ref-1 translocates from the cytoplasm to the nucleus of activated B cells, where it modulates the DNA binding activity of both Pax5a and EBF. Moreover, we show that the repression of APE/Ref-1 protein production is able to block CD40-mediated Pax5a activation. We also provide evidence that APE/Ref-1 can modulate the cooperative activation of the blk promoter operated by Pax5a and EBF and that APE/Ref-1 might directly regulate EBF functional activity. Finally, we show that the interaction between Pax5a and EBF enhances EBF binding activity to its consensus sequence, suggesting that Pax5a can physically interact with EBF and modulate its DNA binding activity.

The recent determination of their primary sequence has lead to the discovery of the metallo-proteolytic activity of the bacterial toxins responsible for tetanus, botulism and anthrax. The protease domain of these toxins enters into the cytosol where it displays a zinc-dependent endopeptidase activity of remarkable specificity. Tetanus neurotoxin and botulinum neurotoxins type B, D, F and G cleave VAMP, an integral protein of the neurotransmitter containing synaptic vesicles. Botulinum neurotoxins type A and E cleave SNAP-25, while the type C neurotoxin cleaves both SNAP-25 and syntaxin, two proteins located on the cytosolic face of the presynaptic membrane. Such specific proteolysis leads to an impaired function of the neuroexocytosis machinery with blockade of neurotransmitter release and consequent paralysis. The lethal factor of Bacillus anthracis is specific for the MAPkinase-kinases which are cleaved within their amino terminus. In this case, however, such specific biochemical lesion could not be correlated with the pathogenesis of anthrax. The recently determined sequence of the vacuolating cytotoxin of Helicobacter pylori contains within its amino terminal domain elements related to serine-proteases, but such an activity as well as its cytosolic target remains to be detected.

The lethal toxin of Bacillus anthracis consists of two proteins, PA and LF, which together induce lethal effects in some animal species and cause macrophage lysis. LF is a zinc-binding protein with metalloprotease activity. With a two-hybrid system approach we identified MAP kinase kinases (MAPKKs) Mekl and Mek2 as proteins interacting with LF. LF was shown to cleave Mek1 and Mek2 and an additional MAPKK family member MKK3, within their N-terminal region. We examined macrophage cell lines and primary peritoneal cells with different sensitivities to LF but did not find a direct correlation between MAPKKs cleavage and cell death. On the other hand, sublytic doses of LF cleave MAPKKs and cause a reduction in the LPS/IFNgamma-induced production of proinflammatory mediators. These findings are discussed with respect to the possible role of LF in the initial phase of infection.

The lethal toxin of Bacillus anthracis consists of two proteins, PA and LF, which together induce lethal effects in animals and cause macrophage lysis. LF is a zinc-endopeptidase which cleaves two mitogen-activated proten kinase kinases (MAPKKs), Mek1 and Mek2, within the cytosol. Here, we show that also MKK3, another dual-specificity kinase that phosphorylates and activates p38 MAP kinase, is cleaved by LF in macrophages. No direct correlation between LF-induced cell death and cleavage of these MAPKKs was found in macrophage cell lines and primary peritoneal cells exhibiting different sensitivity to LF. However, we present the first evidence that sublytic doses of LF cleave Meks and cause a substantial reduction in the production of NO and tumour necrosis factor-α induced by lipopolysaccharide/interferonγ. We suggest that this effect of LF is relevant during the first stages of B. anthracis infection, when a reduction of the inflammatory response would permit growth and diffusion of the bacterium.

Rabaptin-5 functions as an effector for the small GTPase Rab5, a regulator of endocytosis and early endosome fusion. We have searched for structural determinants that confer functional specificity on Rabaptin-5. Here we report that native cytosolic Rabaptin-5 is present in a homodimeric state and dimerization depends upon the presence of its coiled-coil predicted sequences. A 73 residue C-terminal region of Rabaptin-5 is necessary and sufficient both for the interaction with Rab5 and for Rab5-dependent recruitment of the protein on early endosomes. Surprisingly, we uncovered the presence of an additional Rab-binding domain at the N-terminus of Rabaptin-5. This domain mediates the direct interaction with the GTP-bound form of Rab4, a small GTPase that has been implicated in recycling from early endosomes to the cell surface. Based on these results, we propose that Rabaptin-5 functions as a molecular linker between two sequentially acting GTPases to coordinate endocytic and recycling traffic. EMBO J

A survey was conducted of Vibrio spp., Escherichia coli, fecal coliforms, and Salmonella in 644 molluscan shellfish samples marketed in the Apulia region of southern Italy. Vibrios were found in 278 samples (43%), and levels of E. coli and fecal coliforms were above the Italian legal limit in 27 and 34 samples (4 and 5%), respectively. Salmonella was not detected in any of the samples. Because the majority of the vibrio isolates were found in samples that were compliant with Italian regulations, there appears to be no relationship between the presence of microorganisms of fecal origin and the presence of vibrios potentially harmful to human health.