Peter Speelman

Duodenal Infusion of Donor Feces for Recurrent Clostridium difficile

BACKGROUND Recurrent Clostridium difficile infection is difficult to treat, and failure rates for antibiotic therapy are high. We studied the effect of duodenal infusion of donor feces in patients with recurrent C. difficile infection. METHODS We randomly assigned patients to receive one of three therapies: an initial vancomycin regimen (500 mg orally four times per day for 4 days), followed by bowel lavage and subsequent infusion of a solution of donor feces through a nasoduodenal tube; a standard vancomycin regimen (500 mg orally four times per day for 14 days); or a standard vancomycin regimen with bowel lavage. The primary end point was the resolution of diarrhea associated with C. difficile infection without relapse after 10 weeks. RESULTS The study was stopped after an interim analysis. Of 16 patients in the infusion group, 13 (81%) had resolution of C. difficile-associated diarrhea after the first infusion. The 3 remaining patients received a second infusion with feces from a different donor, with resolution in 2 patients. Resolution of C. difficile infection occurred in 4 of 13 patients (31%) receiving vancomycin alone and in 3 of 13 patients (23%) receiving vancomycin with bowel lavage (P<0.001 for both comparisons with the infusion group). No significant differences in adverse events among the three study groups were observed except for mild diarrhea and abdominal cramping in the infusion group on the infusion day. After donor-feces infusion, patients showed increased fecal bacterial diversity, similar to that in healthy donors, with an increase in Bacteroidetes species and clostridium clusters IV and XIVa and a decrease in Proteobacteria species. CONCLUSIONS 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.).

A large outbreak of Legionnaires' disease at a flower show, the Netherlands, 1999.

In 1999, an outbreak of Legionnaires’ disease affected many visitors to a flower show in the Netherlands. To identify the source of the outbreak, we performed an environmental investigation, as well as a case-control study among visitors and a serologic cohort study among exhibitors to measure exposure to possible sources. Of 77,061 visitors, 188 became ill (133 confirmed and 55 probable cases), for an attack rate of 0.23% for visitors and 0.61% for exhibitors. Two whirlpool spas in halls 3 and 4 of the exhibition and a sprinkler in hall 8 were culture positive for Legionella pneumophila. One of three genotypes found in both whirlpool spas was identical to the isolates from 28 of 29 culture-positive patients. Persons who paused at the whirlpool spa in hall 3 were at increased risk for becoming ill. This study illustrates that whirlpool spas may be an important health hazard if disinfection fails.

Role of Toll-Like Receptor 4 in Gram-Positive and Gram-Negative Pneumonia in Mice

ABSTRACT 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-1 Signaling Is Essential for Host Defense during Murine Pulmonary Tuberculosis

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.

TNF-alpha compensates for the impaired host defense of IL-1 type I receptor-deficient mice during pneumococcal pneumonia.

To determine the role of IL-1 in the host defense against pneumonia, IL-1R type I-deficient (IL-1R−/−) and wild-type (Wt) mice were intranasally inoculated with Streptococcus pneumoniae. Pneumonia resulted in elevated IL-1α and IL-1β mRNA and protein levels in the lungs. Survival rates did not differ between IL-1R−/− and Wt mice after inoculation with 5 × 104 or 2 × 105 CFU. At early time points (24 and 48 h) IL-1R−/− mice had 2-log more S. pneumoniae CFU in lungs than Wt mice; at 72 h bacterial outgrowth in lungs was similar in both groups. Upon histopathologic examination IL-1R−/− mice displayed a reduced capacity to form inflammatory infiltrates at 24 h after the induction of pneumonia. IL-1R−/− mice also had significantly less granulocyte influx in bronchoalveolar lavage fluid at 24 h after inoculation. Since TNF is known to enhance host defense during pneumonia, we determined the role of endogenous TNF in the early impairment and subsequent recovery of defense mechanisms in IL-1R−/− mice. All IL-1R−/− mice treated with anti-TNF rapidly died (no survivors (of 14 mice) after 4 days), while 10-day survival in IL-1R−/− mice (control Ab), Wt mice (anti-TNF), and Wt mice (control Ab) was 7 of 13, 3 of 14, and 12 of 13, respectively. These data suggest that TNF is more important for host defense against pneumococcal pneumonia than IL-1, and that the impaired early host defense in IL-1R−/− mice is compensated for by TNF at a later phase.

Elevated Plasma Concentrations of Interferon (IFN)-γ and the IFN-γ—Inducing Cytokines Interleukin (IL)-18, IL-12, and IL-15 in Severe Melioidosis

Interferon (IFN)-gamma plays an important role in the pathogenesis of sepsis. Production of IFN-gamma is stimulated by synergistic effects of interleukin (IL)-18, IL-12, and IL-15. To investigate the regulation of IFN-gamma production during severe gram-negative infection, the plasma concentrations of IFN-gamma, IL-18, IL-12, and IL-15 were measured in 83 patients with suspected melioidosis. The diagnosis was confirmed in 62 patients, 31 of whom had blood cultures positive for Burkholderia pseudomallei, of whom 12 died. Compared with healthy controls, patients had elevated levels of IFN-gamma, IL-18, IL-12p40, and IL-15 on admission, with significantly higher levels in blood culture-positive patients, and these levels remained elevated during the 72-h study period. In whole blood stimulated with heat-killed B. pseudomallei, anti-IL-12 had a stronger inhibitory effect than anti-IL-18 and anti-IL-15 on IFN-gamma production. This effect of anti-IL-12 was further enhanced by anti-IL-18. These data suggest that during gram-negative sepsis, IFN-gamma production is controlled at least in part by endogenous IL-18, IL-12, and IL-15.

CpG Oligodeoxynucleotides Enhance Host Defense during Murine Tuberculosis

ABSTRACT Oligodeoxynucleotides (ODNs) containing unmethylated CpG motifs activate immune cells to produce cytokines. CpG ODNs protect mice against infections with intracellular bacteria by the induction of a T helper 1 (Th1) response. To determine the effect of CpG ODNs in pulmonary tuberculosis, mice were treated with CpG ODNs or control ODNs at the time of intranasal infection. CpG ODNs reduced mycobacterial outgrowth for up to 5 weeks after Mycobacterium tuberculosis infection and were associated with a decrease in inflammation in lung tissue. CpG treatment was also associated with elevated levels of gamma interferon (IFN-γ) and decreased levels of interleukin 4 in the lungs and an increased capacity of splenocytes to secrete Th1-type cytokines. CpG ODNs given 2 weeks after infection were still able to reduce mycobacterial outgrowth and to enhance a Th1 response 5 weeks postinfection. Administration of CpG ODNs to IFN-γ-gene-deficient mice failed to reduce mycobacterial outgrowth. These data suggest that CpG ODNs improve host defense during pulmonary tuberculosis by an IFN-γ-dependent mechanism.

IL-18 Improves the Early Antimicrobial Host Response to Pneumococcal Pneumonia

To determine the role of endogenous IL-18 during pneumonia, IL-18 gene-deficient (IL-18−/−) mice and wild-type (WT) mice were intranasally inoculated with Streptococcus pneumoniae, the most common causative agent of community-acquired pneumonia. Infection with S. pneumoniae increased the expression of IL-18 mRNA and was associated with elevated concentrations of both precursor and mature IL-18 protein within the lungs. IL-18−/− mice had significantly more bacteria in their lungs and were more susceptible for progressing to systemic infection at 24 and 48 h postinoculation. Similarly, treatment of WT mice with anti-IL-18 was associated with enhanced outgrowth of pneumococci. In contrast, the clearance of pneumococci from lungs of IL-12−/− mice was unaltered when compared with WT mice. Furthermore, anti-IL-12 did not influence bacterial clearance in either IL-18−/− or WT mice. These data suggest that endogenous IL-18, but not IL-12, plays an important role in the early antibacterial host response during pneumococcal pneumonia.

Legionnaires' Disease at a Dutch Flower Show: Prognostic Factors and Impact of Therapy

After a large outbreak of Legionnaires’ disease in the Netherlands, we determined risk factors for intensive care unit (ICU) admission and death and the impact of adequate therapy on ICU-free survival among 141 hospitalized patients. Overall mortality rate was 13%, and ICU mortality rate was 36%. Smoking, temperature >38.5°C, and bilateral infiltrates shown on chest x-ray were independent risk factors for ICU admission or death (all p<0.05). Starting adequate therapy within 24 hours after admission resulted in a higher ICU-free survival rate compared to therapy initiation after 24 hours: 78% versus 54%, respectively (p=0.005). However, delay in providing therapy to patients with urinary antigen tests with negative results did not influence outcome. These data suggest that by using the urinary antigen test on admission a more tailored approach to patients with community-acquired pneumonia may be applied.

Improved Host Defense against Pneumococcal Pneumonia in Platelet-Activating Factor Receptor-Deficient Mice

Platelet-activating factor (PAF) is a phospholipid with proinflammatory properties that binds to a specific receptor (PAF receptor [PAFR]) that is expressed on many different cell types. PAFR is able to bind phosphorylcholine, which is present in both PAF and the pneumococcal cell wall. Activation of respiratory epithelial cells in vitro results in up-regulation of PAFR, which, in turn, facilitates invasion of Streptococcus pneumoniae. To determine the role of PAFR in host defense against pneumococcal pneumonia, PAFR-deficient (PAFR(-/-)) and wild-type (wt) mice were inoculated intranasally with S. pneumoniae. PAFR(-/-) mice were relatively resistant to pneumococcal pneumonia, as indicated by delayed and reduced mortality, diminished outgrowth of pneumococci in lungs, and reduced dissemination of the infection (all P<.05, vs. wt mice). PAFR(-/-) mice also had less pulmonary inflammation. These data provide evidence that PAFR is used by S. pneumoniae to induce lethal pneumonia.