Bacteremia due to Clostridium difficile--review of the literature

Mycotic Iliac Artery Aneurysm Caused by Clostridium difficile in a Patient with Axillobifemoral Bypass for Leriche Syndrome

A 74-year old man on hemodialysis developed a mycotic aneurysm caused by Clostridium difficile. To the best of our knowledge, this is only the second case of such an aneurysm reported in the literature. He had previously undergone axillobifemoral bypass grafting because of symptomatic infrarenal aortic stenosis. Although no blood flow was detected in his occluded right common iliac artery, it expanded rapidly despite intensive antibiotic therapy. As the blood supply to the lower limbs was already secured, only resection of the infected arteries was performed.

Pseudomembranous colitis due to Clostridium difficile as a cause of perineal necrotising fasciitis

Although rare, pseudomembranous colitis may be a cause of perineal necrotising fasciitis in a context of immunosuppression, as in the case we report. This origin must be quickly identified because the therapeutic management, especially surgery, is unlikely to be the same as usual. Similarly, antibiotic treatment is also a matter of discussion due to the potential deleterious role of antibiotics in pseudomembranous colitis.

Contribution of adenosine A(2B) receptors in Clostridium difficile intoxication and infection

Clostridium difficile toxins A (TcdA) and B (TcdB) induce a pronounced systemic and intestinal inflammatory response. A(2B) adenosine receptors (A(2B)ARs) are the predominant adenosine receptors in the intestinal epithelium. We investigated whether A(2B)ARs are upregulated in human intestinal cells by TcdA or TcdB and whether blockade of A(2B)ARs can ameliorate C. difficile TcdA-induced enteritis and alter the outcome of C. difficile infection (CDI). Adenosine receptor subtype (A(1), A(2A), A(2B), and A(3)) mRNAs were assayed in HCT-8 cells. Ileal loops from wild-type rabbits and mice and A(2B)AR(-/-) mice were treated with TcdA, with or without the selective A(2B)AR antagonist ATL692 or PSB1115. A murine model of CDI was used to determine the effect of A(2B)AR deletion or blockade with the orally available agent ATL801, on clinical outcome, histopathology and intestinal interleukin-6 (IL-6) expression from infection. TcdA and TcdB upregulated A(2B)AR gene expression in HCT-8 cells. ATL692 decreased TcdA-induced secretion and epithelial injury in rabbit ileum. Deletion of A(2B)ARs reduced secretion and histopathology in TcdA-challenged mouse ileum. Deletion or blockade of A(2B)ARs reduced histopathology, IL-6 expression, weight loss, diarrhea, and mortality in C. difficile-infected mice. A(2B)ARs mediate C. difficile toxin-induced enteritis and disease. Inhibition of A(2B)AR activation may be a potential strategy to limit morbidity and mortality from CDI.

Clostridium difficile infection: clinical spectrum and approach to management

Clostridium difficile is recognized globally as an important enteric pathogen associated with considerable morbidity and mortality due to the widespread use of antibiotics. The overall incidence of C. difficile-associated diarrhea (CDAD) is increasing due to the emergence of a hypervirulent strain known as NAP1/BI/027. C. difficile acquisition by a host can result in a varied spectrum of clinical conditions inclusive of both colonic and extracolonic manifestations. Repeated occurrence of CDAD, manifested by the sudden re-appearance of diarrhea and other symptoms usually within a week of stopping treatment, makes it a difficult clinical problem. C. difficile infection has also been reported to be involved in exacerbation of inflammatory bowel diseases. The first step in the management of a suspected CDAD case is the withdrawal of the offending agent and changing the antibiotic regimens. Antimicrobial therapy directed against C. difficile viz. metronidazole for mild cases and vancomycin for severe cases is needed. For patients with ileus, oral vancomycin with simultaneous intravenous (IV) metronidazole and intracolonic vancomycin may be given. Depending on the severity of disease, the further line of management may include surgery, IV immunoglobulin treatment or high dose of vancomycin. Adjunctive measures used for CDAD are probiotics and prebiotics, fecotherapy, adsorbents and immunoglobulin therapy. Among the new therapies fidaxomicin has recently been approved by the American Food and Drugs Administration for treatment of CDAD.

Two case reports of Clostridium difficile bacteremia, one with the epidemic NAP-1 strain

Clostridium difficile bacteremia is rare. Here, we report two cases of C. difficile bacteremia in patients with significant underlying gastrointestinal pathology. In one case, the bacteremia was caused by the North American pulsed-field gel electrophoresis (PFGE) type 1 (NAP-1) strain, which is responsible for recent outbreaks of C. difficile infections of increased severity.

Exposure to a social stressor alters the structure of the intestinal microbiota: implications for stressor-induced immunomodulation

The bodies of most animals are populated by highly complex and genetically diverse communities of microorganisms. The majority of these microbes reside within the intestines in largely stable but dynamically interactive climax communities that positively interact with their host. Studies from this laboratory have shown that stressor exposure impacts the stability of the microbiota and leads to bacterial translocation. The biological importance of these alterations, however, is not well understood. To determine whether the microbiome contributes to stressor-induced immunoenhancement, mice were exposed to a social stressor called social disruption (SDR), that increases circulating cytokines and primes the innate immune system for enhanced reactivity. Bacterial populations in the cecum were characterized using bacterial tag-encoded FLX amplicon pyrosequencing. Stressor exposure significantly changed the community structure of the microbiota, particularly when the microbiota were assessed immediately after stressor exposure. Most notably, stressor exposure decreased the relative abundance of bacteria in the genus Bacteroides, while increasing the relative abundance of bacteria in the genus Clostridium. The stressor also increased circulating levels of IL-6 and MCP-1, which were significantly correlated with stressor-induced changes to three bacterial genera (i.e., Coprococcus, Pseudobutyrivibrio, and Dorea). In follow up experiments, mice were treated with an antibiotic cocktail to determine whether reducing the microbiota would abrogate the stressor-induced increases in circulating cytokines. Exposure to SDR failed to increase IL-6 and MCP-1 in the antibiotic treated mice. These data show that exposure to SDR significantly affects bacterial populations in the intestines, and remarkably also suggest that the microbiota are necessary for stressor-induced increases in circulating cytokines.

Bacteraemia and breast abscess: unusual extra-intestinal manifestations of Clostridium difficile infection

Extra-intestinal manifestations of Clostridium difficile infection are uncommon. Most cases are associated with gastrointestinal disease and often occur as a mixed infection with other gut flora. We report a case of breast abscess following monomicrobial C. difficile bacteraemia in a female with background chronic hepatitis C infection and alcoholic liver disease. No evidence of colitis was found. Our case shows that C. difficile is indeed capable of spreading from the gastrointestinal tract.

Clostridium difficile bacteremia, Taiwan

To determine clinical characteristics and outcome of patients with Clostridium difficile bacteremia (CDB), we identified 12 patients with CDB in 2 medical centers in Taiwan; all had underlying systemic diseases. Five had gastrointestinal diseases or conditions, including pseudomembranous colitis (2 patients); 4 recalled diarrhea, but only 5 had recent exposure to antimicrobial drugs. Ten available isolates were susceptible to metronidazole and vancomycin. Five isolates had C. difficile toxin A or B. Of 5 patients who died, 3 died of CDB. Of 8 patients treated with metronidazole or vancomycin, only 1 died, and all 4 patients treated with other drugs died (12.5% vs. 100%; p = 0.01). C. difficile bacteremia, although uncommon, is thus associated with substaintial illness and death rates.

The ecology and pathobiology of Clostridium difficile infections: an interdisciplinary challenge

Clostridium difficile is a well recognized pathogen of humans and animals. Although C. difficile was first identified over 70 years ago, much remains unknown in regards to the primary source of human acquisition and its pathobiology. These deficits in our knowledge have been intensified by dramatic increases in both the frequency and severity of disease in humans over the last decade. The changes in C. difficile epidemiology might be due to the emergence of a hypervirulent stain of C. difficile, ageing of the population, altered risk of developing infection with newer medications, and/or increased exposure to C. difficile outside of hospitals. In recent years, there have been numerous reports documenting C. difficile contamination of various foods, and reports of similarities between strains that infect animals and strains that infect humans as well. The purposes of this review are to highlight the many challenges to diagnosing, treating, and preventing C. difficile infection in humans, and to stress that collaboration between human and veterinary researchers is needed to control this pathogen.

Spore-forming Bacilli and Clostridia in human disease

Many Gram-positive spore-forming bacteria in the Firmicute phylum are important members of the human commensal microbiota, which, in rare cases, cause opportunistic infections. Other spore-formers, however, have evolved to become dedicated pathogens that can cause a striking variety of diseases. Despite variations in disease presentation, the etiologic agent is often the spore, with bacterially produced toxins playing a central role in the pathophysiology of infection. This review will focus on the specific diseases caused by spores of the Clostridia and Bacilli.

Clostridium difficile infection: An overview of the disease and its pathogenesis, epidemiology and interventions

Clostridium difficile infection (CDI) is the primary cause of antibiotic-associated diarrhea and is a significant nosocomial disease. In the past ten years, variant toxin-producing strains of C. difficile have emerged, that have been associated with severe disease as well as outbreaks worldwide. This review summarizes current information on C. difficile pathogenesis and disease, and highlights interventions used to combat single and recurrent episodes of CDI.