The infusion of donor feces was significantly more effective for the treatment of recurrent C. difficile infection than the use of vancomycin. (Funded by the Netherlands Organization for Health Research and Development and the Netherlands Organization for Scientific Research; Netherlands Trial Register number, NTR1177.).

To determine the role of Toll-like receptor 4 (TLR4) in the immune response to pneumonia, C3H/HeJ mice (which display a mutant nonfunctional TLR4) and C3H/HeN wild-type mice were intranasally infected with either Streptococcus pneumoniae (a common gram-positive respiratory pathogen) or Klebsiella pneumoniae (a common gram-negative respiratory pathogen). In cases of pneumococcal pneumonia, TLR4 mutant mice showed a reduced survival only after infection with low-level bacterial doses, which was associated with a higher bacterial burden in their lungs 48 h postinfection. In Klebsiella pneumonia, TLR4 mutant mice demonstrated a shortened survival after infection with either a low-or a high-level bacterial dose together with an enhanced bacterial outgrowth in their lungs. These data suggest that TLR4 contributes to a protective immune response in both pneumococcal and Klebsiella pneumonia and that its role is more important in respiratory tract infection caused by the latter (gram-negative) pathogen.

Interleukin (IL)-1 signaling is required for the containment of infections with intracellular microorganisms, such as Listeria monocytogenes and Leishmania major. To determine the role of IL-1 in the host response to tuberculosis, we infected IL-1 type I receptor-deficient (IL-1R(-/-)) mice, in which IL-1 does not exert effects, with Mycobacterium tuberculosis. IL-1R(-/-) mice were more susceptible to pulmonary tuberculosis, as reflected by an increased mortality and an enhanced mycobacterial outgrowth in lungs and distant organs, which was associated with defective granuloma formation, containing fewer macrophages and fewer lymphocytes, whereas granulocytes were abundant. Lymphocytes were predominantly confined to perivascular areas, suggesting a defective migration of cells into inflamed tissue in the absence of IL-1 signaling. Impaired host defense in IL-1R(-/-) mice was further characterized by a decrease in the ability of splenocytes to produce interferon-gamma. Analysis of these data suggests that IL-1 plays an important role in the immune response to M. tuberculosis.

No abstract

Discontinuing amoxicillin treatment after three days is not inferior to discontinuing it after eight days in adults admitted to hospital with mild to moderate-severe community acquired pneumonia who substantially improved after an initial three days' treatment.

During TB cytokines play a role in host defence. To determine the cytokine pattern during various disease stages of TB, serum levels of IL-12, interferon-gamma (IFN-gamma), IL-4, IL-6 and IL-10 were measured in 81 patients with active TB, 15 patients during therapy and 26 patients after anti-tuberculous therapy as well as in 16 persons who had been in close contact with smear-positive TB and in 17 healthy controls. IFN-gamma was elevated during active TB when compared with healthy controls, declining during and after treatment. IL-12 (p40 and p70) serum levels were not significantly higher in patients with active TB compared with any of the other groups. IL-4 levels were low in all groups. IL-6 and IL-10 serum levels were elevated in patients with active TB and during treatment. In patients with active TB serum levels of IFN-gamma and IL-6 were higher in patients with fever, anorexia and malaise. IL-12 levels were higher in patients with a positive smear. Cytokine levels did not correlate with localization of TB (pulmonary versus extrapulmonary), or skin test positivity. Cytokines directing a Th1 response (IL-12) or a Th2 response (IL-4) were not elevated in sera of this large group of patients with pulmonary and extrapulmonary TB. In patients with active TB, cytokines that were elevated in serum were IFN-gamma, IL-6 and IL-10.

Hyposplenic patients are at risk of overwhelming post-splenectomy infection (OPSI), which carries mortality of up to 70%. Therefore, preventive measures are warranted. However, patients with diminished splenic function are difficult to identify. In this review we discuss immunological, haematological and scintigraphic parameters that can be used to measure splenic function. IgM memory B cells are a potential parameter for assessing splenic function; however, more studies are necessary for its validation. Detection of Howell–Jolly bodies does not reflect splenic function accurately, whereas determining the percentage of pitted erythrocytes is a well-evaluated method and seems a good first-line investigation for assessing splenic function. When assessing spleen function, 99mTc-labelled, heat-altered, autologous erythrocyte scintigraphy with multimodality single photon emission computed tomography (SPECT)-CT technology is the best approach, as all facets of splenic function are evaluated. In conclusion, although scintigraphic methods are most reliable, they are not suitable for screening large populations. We therefore recommend using the percentage of pitted erythrocytes, albeit suboptimal, as a first-line investigation and subsequently confirming abnormal readings by means of scintigraphy. More studies evaluating the value of potentially new markers are needed.

Cell recruitment is a multistep process regulated by cytokines, chemokines, and growth factors. Previous work has indicated that the urokinase plasminogen activator receptor (uPAR) may also play a role in this mechanism, presumably by an interaction with the β2 integrin CD11b/CD18. Indeed, an essential role of uPAR in neutrophil recruitment during pulmonary infection has been demonstrated for β2 integrin-dependent respiratory pathogens. We investigated the role of uPAR and urokinase plasminogen activator (uPA) during pneumonia caused by a β2 integrin-independent respiratory pathogen, Streptococcus pneumoniae. uPAR-deficient (uPAR−/−), uPA-deficient (uPA−/−), and wild-type (Wt) mice were intranasally inoculated with 105 CFU S. pneumoniae. uPAR−/− mice showed reduced granulocyte accumulation in alveoli and lungs when compared with Wt mice, which was associated with more S. pneumoniae CFU in lungs, enhanced dissemination of the infection, and a reduced survival. In contrast, uPA−/− mice showed enhanced host defense, with more neutrophil influx and less pneumococci in the lungs compared with Wt mice. These data suggest that uPAR is necessary for adequate recruitment of neutrophils into the alveoli and lungs during pneumonia caused by S. pneumoniae, a pathogen eliciting a β2 integrin-independent inflammatory response. This function is even more pronounced when uPAR is unoccupied by uPA.