Recurrent Clostridium difficile diarrhoea

Acid Suppression Medications During Hospitalization as a Risk Factor for Recurrence of Clostridioides difficile Infection: Systematic Review and Meta-analysis

BACKGROUND

Studies have had conflicting results regarding the influence of acid-suppression medications (ASMs) during hospitalization on the recurrence of Clostridioides difficile infection (CDI).

METHODS

A systematic review and meta-analysis investigating the association between recurrent CDI and ASM use in inpatients was performed. Relevant literature was identified using Medline, Google Scholar, and Web of Science. All human studies were considered regardless of publication date. Case-control and cohort studies and clinical trials were included if they contained the necessary information to calculate appropriate statistics related to the objective of this study. Review articles, meta-analyses, and commentaries were excluded; however, their references were searched to identify any studies missed. The random-effects model was selected since significant heterogeneity in study design was identified. To evaluate the sensitivity of the analysis various subgroup analyses were performed.

RESULTS

Our search identified 9 studies involving 5668 patients of whom 1003 (17.7%) developed recurrent CDI. Patients on ASM were 64% more likely to develop recurrent CDI than patients not on ASM (OR, 1.64; 95% CI, 1.13-2.38; P = .009; I2 = 79.54%). Proton pump inhibitor (PPI) use was associated with an 84% increased risk of recurrent CDI versus no ASM (OR, 1.84; 95% CI, 1.18-2.85; P = .007; I2 = 83.4%).

CONCLUSIONS

ASM use during hospitalization was associated with a 64% increase in recurrent CDI. The association was greater with PPI use. Due to significant heterogeneity in the analyses, additional studies are essential to further elucidate iatrogenic effects of ASM. Unnecessary PPI use should be discontinued.

In vivo efficacy of auranofin in a hamster model of Clostridioides difficile infection

Clostridioides difficile infections (CDIs) are an urgent public health threat worldwide and are a leading cause of morbidity and mortality in healthcare settings. The increasing incidence and severity of infections combined with the scarcity of effective anti-CDI agents has made treatment of CDI very challenging. Therefore, development of new, effective anticlostridial agents remains a high priority. The current study investigated the in vivo efficacy of auranofin in a CDI hamster model. All hamsters treated with auranofin (5 mg/kg) survived a lethal challenge with C. difficile. Furthermore, auranofin (5 mg/kg) was as effective as vancomycin, the drug of choice for treatment of CDIs, against relapsing CDI. Furthermore, auranofin (5 mg/kg) generated a 3.15-log₁₀ reduction (99.97%) in C. difficile count in the cecal contents of hamsters. These results indicate that auranofin warrants further investigation as a new agent to replenish the pipeline of anti-CDI therapeutics.

Microbiota-mediated protection against antibiotic-resistant pathogens

Colonization by the microbiota provides one of our most effective barriers against infection by pathogenic microbes. The microbiota protects against infection by priming immune defenses, by metabolic exclusion of pathogens from their preferred niches, and through direct antimicrobial antagonism. Disruption of the microbiota, especially by antibiotics, is a major risk factor for bacterial pathogen colonization. Restoration of the microbiota through microbiota transplantation has been shown to be an effective way to reduce pathogen burden in the intestine but comes with a number of drawbacks, including the possibility of transferring other pathogens into the host, lack of standardization, and potential disruption to host metabolism. More refined methods to exploit the power of the microbiota would allow us to utilize its protective power without the drawbacks of fecal microbiota transplantation. To achieve this requires detailed understanding of which members of the microbiota protect against specific pathogens and the mechanistic basis for their effects. In this review, we will discuss the clinical and experimental evidence that has begun to reveal which members of the microbiota protect against some of the most troublesome antibiotic-resistant pathogens: Klebsiella pneumoniae, vancomycin-resistant enterococci, and Clostridioides difficile.

Epidemiology and Risk Factors for Community Associated Clostridioides difficile in Children

OBJECTIVE

To assess which risk factors are associated with community-associated Clostridioides difficile infection (CDI) in children.

STUDY DESIGN

This case control study was a retrospective review of all children 1-17 years of age with stool specimens sent for C difficile testing from January 1, 2012, to December 31, 2016. Cases and controls were children who had C difficile testing performed in the community or first 48 hours of hospital admission and >12 weeks after hospital discharge, with no prior positive C difficile testing in last 8 weeks, without other identified causes of diarrhea, and with clinical symptoms. Cases had positive confirmatory testing for C difficile. Controls had negative testing for C difficile and were matched to cases 1:1 by age and year of specimen collection.

RESULTS

The overall incidence rate of community-acquired CDI in this cohort was 13.7 per 100 000 children per year. There was a substantial increase in community-acquired CDI from 9.6 per 100 000 children per year in 2012 to a peak of 16.9 per 100 000 children per year in 2015 (Cochran-Armitage test for trend P = .002). The risk factors for community-acquired CDI included non-Hispanic ethnicity; amoxicillin-clavulanate, cephalosporin, and clindamycin use within the previous 12 weeks; a previous positive C difficile test within 6 months; and increased health care visits in the last year.

CONCLUSIONS

As rates of community-acquired CDI are increasing, enhanced antibiotic stewardship and recognition of health care disparities may ease the burden of community-acquired CDI.

In vitro and in vivo anti-clostridial activity of newly isolated Pediococcus acidilactici SPM138 against Clostridium difficile

Clostridium difficile infection (CDI) has become a growing health concern, as evident from the increase in the mortality rate among elderly or hospitalized patients. Treatment of CDI is usually based on antibiotics (metronidazole and vancomycin), but it has some limitations, including cost and antibiotic resistance. Probiotics could offer an effective remedy to prevent CDI and could be an auxiliary agent in treatment CDI. Here, the anti-clostridial activity of a newly isolated probiotic strain, Pediococcus acidilactici SPM138 (SPM138) was evaluated. The cultivation of C. difficile (CD) with SPM138, inhibited the growth of CD and significantly reduced CD toxins level. The result of MTT assay showed that, incubation with 25% CD culture supernatant decreased the survival rate of HT-29 cells to less than 20%. However, the survival rate of these cells increased to 98% in the presence of the 25% CD + SPM138 supernatant. The mRNA expression of IL-6, IL-8 and PTGS2 in HT-29 cells decreased by more than 60% upon incubation with CD + SPM138 co-cultures as compared to the levels observed after treatment with CD supernatant only. The concentration of IL-8 also decreased by more than 60% upon treatment with CD + SPM138 co-culture supernatant. In a C. difficile PCR ribotype 027-infected mouse model, the concentration of CD toxin in stool samples of SPM138-fed mice was only 37% of that reported in C. difficile 027-infected group. These findings show that P. acidilactici SPM138 may be a promising probiotic in CDI.

Role of the global regulator Rex in control of NAD+ -regeneration in Clostridioides (Clostridium) difficile

For the human pathogen Clostridioides (also known as Clostridium) difficile, the ability to adapt to nutrient availability is critical for its proliferation and production of toxins during infection. Synthesis of the toxins is regulated by the availability of certain carbon sources, fermentation products and amino acids (e.g. proline, cysteine, isoleucine, leucine and valine). The effect of proline is attributable at least in part to its role as an inducer and substrate of D-proline reductase (PR), a Stickland reaction that regenerates NAD⁺ from NADH. Many Clostridium spp. use Stickland metabolism (co-fermentation of pairs of amino acids) to generate ATP and NAD⁺ . Synthesis of PR is activated by PrdR, a proline-responsive regulatory protein. Here we report that PrdR, in the presence of proline, represses other NAD⁺ -generating pathways, such as the glycine reductase and succinate-acetyl CoA utilization pathways leading to butyrate production, but does so indirectly by affecting the activity of Rex, a global redox-sensing regulator that responds to the NAD⁺ /NADH ratio. Our results indicate that PR activity is the favored mechanism for NAD⁺ regeneration and that both Rex and PrdR influence toxin production. Using the hamster model of C. difficile infection, we revealed the importance of PrdR-regulated Stickland metabolism in the virulence of C. difficile.

Clostridium difficile and cystic fibrosis: management strategies and the role of faecal transplantation

Clostridium difficile is a bacterial infection that colonises the gut in susceptible hosts. It is associated with exposure to healthcare settings and antibiotic use. It could be assumed that cystic fibrosis (CF) patients are a high-risk group for C.difficile. However, despite high carriage rates, CF patients have low rates of active disease. There are guidelines for the treatment of C.difficile, however little is published specific to treating C.difficile in CF. This article provides an overview of the current management strategies for C.difficile in CF, including a description of the first faecal transplantation in this patient population.

Economic evaluation of fecal microbiota transplantation for the treatment of recurrent Clostridium difficile infection in Australia

BACKGROUND AND AIM

Clostridium difficile is the most common cause of hospital-acquired diarrhea in Australia. In 2013, a randomized controlled trial demonstrated the effectiveness of fecal microbiota transplantation (FMT) for the treatment of recurrent Clostridium difficile infection (CDI). The aim of this study is to evaluate the cost-effectiveness of fecal microbiota transplantation-via either nasoduodenal or colorectal delivery-compared with vancomycin for the treatment of recurrent CDI in Australia.

METHODS

A Markov model was developed to compare the cost-effectiveness of fecal microbiota transplantation compared with standard antibiotic therapy. A literature review of clinical evidence informed the structure of the model and the choice of parameter values. Clinical effectiveness was measured in terms of quality-adjusted life years. Uncertainty in the model was explored using probabilistic sensitivity analysis.

RESULTS

Both nasoduodenal and colorectal FMT resulted in improved quality of life and reduced cost compared with vancomycin. The incremental effectiveness of either FMT delivery compared with vancomycin was 1.2 (95% CI: 0.1, 2.3) quality-adjusted life years, or 1.4 (95% CI: 0.4, 2.4) life years saved. Treatment with vancomycin resulted in an increased cost of AU$4094 (95% CI: AU$26, AU$8161) compared with nasoduodenal delivery of FMT and AU$4045 (95% CI: -AU$33, AU$8124) compared with colorectal delivery. The mean difference in cost between colorectal and nasoduodenal FMT was not significant.

CONCLUSIONS

If FMT, rather than vancomycin, became standard care for recurrent CDI in Australia, the estimated national healthcare savings would be over AU$4000 per treated person, with a substantial increase in quality of life.

Molecular characteristics of Clostridium difficile strains from patients with a first recurrence more than 8 weeks after the primary infection

BACKGROUND/PURPOSE

Nearly all published studies of recurrent Clostridium difficile infections (CDI) report recurrent CDI within 8 weeks after the primary infection. This study explored the molecular characteristics of C. difficile isolates from the first recurrent CDI more than 8 weeks after the primary infection.

METHODS

Consecutive hospitalized patients with a recurrent CDI more than 8 weeks after a primary infection were enrolled prospectively from January 2008 to February 2011. All C. difficile isolates of the primary and recurrent infections were collected and subjected to polymerase chain reaction ribotyping and antimicrobial susceptibility testing.

RESULTS

There were 62 cases of CDI in this study, which included 32 cases (51.6%) of recurrence due to the same ribotype of C. difficile, 26 (41.9%) cases due to a different ribotype, and four (6.5%) cases with 2-4 recurrences due to the same or different strains. One hundred and forty C. difficile isolates were obtained, which included 62 primary CDI isolates and 78 recurrent isolates. Ribotype 020 was the most common C. difficile strain in primary and recurrent infections. Ribotype 001 accounted for 15.4% (10/78) of recurrent infections and 3.2% (2/62) of primary infections (p = 0.0447). The minimum inhibitory concentration at 90% (MIC₉₀) values of linezolid, moxifloxacin, and clindamycin against type 001 strains were much higher, compared to the three other common ribotypes.

CONCLUSION

Recurrent CDI more than 8 weeks after a primary infection can be caused by the same or different C. difficile ribotype at similar percentages. Ribotype 001 C. difficile strains, which have a lower susceptibility to antimicrobials, were isolated more frequently in patients with a recurrent CDI.

Novel risk factors for recurrent Clostridium difficile infection in children

OBJECTIVES

Clostridium difficile, a common cause of antibiotic-associated diarrhea, has been reported to recur in high rates in adults. The rates and risk factors for recurrent C difficile infection (rCDI) in children have not been well established.

METHODS

We conducted a retrospective cohort study of 186 pediatric patients seen at a tertiary care referral center for a 5-year period diagnosed as having a primary C difficile infection. Children with recurrent disease, defined as return of symptoms of C difficile infection and positive testing ≤60 days after the completion of therapy, were compared with children who did not experience an episode of recurrence.

RESULTS

Of the 186 pediatric patients included in this study, 41 (22%) experienced rCDI. On univariable analysis, factors significantly associated with rCDI included malignancy, recent hospitalization, recent surgery, antibiotic use, number of antibiotic exposures by class, acid blocker use, immunosuppressant use, and hospital-acquired disease. On multivariable analysis, malignancy (odds ratio [OR] 3.39, 95% confidence interval [CI] 1.52-7.85), recent surgery (OR 2.40, 95% CI 1.05-5.52), and the number of antibiotic exposures by class (OR 1.33, 95% CI 1.01-1.75) were significantly associated with recurrent disease in children.

CONCLUSIONS

The rate of rCDI in children was 22%. Recurrence was significantly associated with the risk factors of malignancy, recent surgery, and the number of antibiotic exposures by class.

Clinical predictors of recurrent Clostridium difficile infection in out-patients

BACKGROUND

Clostridium difficile infection (CDI) recurs in 20-30% of patients.

AIM

To describe the predictors of recurrence in out-patients with CDI.

METHODS

Out-patient cases of CDI in Olmsted County, MN residents diagnosed between 28 June 2007 and 25 June 2010 were identified. Recurrent CDI was defined as recurrence of diarrhoea with a positive C. difficile PCR test from 15 to 56 days after the initial diagnosis with interim resolution of symptoms. Patients who had two positive tests within 14 days were excluded. Cox proportional hazard models were used to assess the association of clinical variables with time to recurrence of CDI.

RESULTS

The cohort included 520 out-patients; 104 had recurrent CDI (cumulative incidence of 17.5% by 30 days). Univariate analysis identified increasing age and antibiotic use to be associated with recurrent CDI. Severe CDI, peripheral leucocyte count and change in serum creatinine >1.5-fold were not. In a multiple variable model, concomitant antibiotic use was associated with risk of recurrent CDI (HR = 5.4, 95% CI 1.6-17.5, P = 0.005), while age (HR per 10 year increase = 1.1, 95% CI 0.9-1.3, P = 0.22); peripheral leucocyte count >15 × 10(9) /L (HR = 1.0, 95% CI 0.5-2.1, P = 0.92); and change in serum creatinine greater than 1.5-fold (HR = 0.8, 95% CI 0.4-1.5, P = 0.44) were not.

CONCLUSIONS

Antibiotic use was independently associated with a dramatic risk of recurrent Clostridium difficile infection in an out-patient cohort. It is important to avoid unnecessary systemic antibiotics in patients with Clostridium difficile infection, and patients with ongoing antibiotic use should be monitored closely for recurrent infection.

Cost-effectiveness analysis of fidaxomicin versus vancomycin in Clostridium difficile infection

Objectives

Fidaxomicin was non-inferior to vancomycin with respect to clinical cure rates in the treatment of Clostridium difficile infections (CDIs) in two Phase III trials, but was associated with significantly fewer recurrences than vancomycin. This economic analysis investigated the cost-effectiveness of fidaxomicin compared with vancomycin in patients with severe CDI and in patients with their first CDI recurrence.

Methods

A 1 year time horizon Markov model with seven health states was developed from the perspective of Scottish public healthcare providers. Model inputs for effectiveness, resource use, direct costs and utilities were obtained from published sources and a Scottish expert panel. The main model outcome was the incremental cost-effectiveness ratio (ICER), expressed as cost per quality-adjusted life year (QALY), for fidaxomicin versus vancomycin; ICERs were interpreted using willingness-to-pay thresholds of £20 000/QALY and £30 000/QALY. One-way and probabilistic sensitivity analyses were performed.

Results

Total costs were similar with fidaxomicin and vancomycin in patients with severe CDI (£14 515 and £14 344, respectively) and in patients with a first recurrence (£16 535 and £16 926, respectively). Improvements in clinical outcomes with fidaxomicin resulted in small QALY gains versus vancomycin (severe CDI, +0.010; patients with first recurrence, +0.019). Fidaxomicin was cost-effective in severe CDI (ICER £16 529/QALY) and dominant (i.e. more effective and less costly) in patients with a first recurrence. The probability that fidaxomicin was cost-effective at a willingness-to-pay threshold of £30 000/QALY was 60% for severe CDI and 68% in a first recurrence.

Conclusions

Fidaxomicin is cost-effective in patients with severe CDI and in patients with a first CDI recurrence versus vancomycin.

Lactobacillus rhamnosus L34 and Lactobacillus casei L39 suppress Clostridium difficile-induced IL-8 production by colonic epithelial cells

Background

Clostridium difficile is the main cause of hospital-acquired diarrhea and colitis known as C. difficile-associated disease (CDAD).With increased severity and failure of treatment in CDAD, new approaches for prevention and treatment, such as the use of probiotics, are needed. Since the pathogenesis of CDAD involves an inflammatory response with a massive influx of neutrophils recruited by interleukin (IL)-8, this study aimed to investigate the probiotic effects of Lactobacillus spp. on the suppression of IL-8 production in response to C. difficile infection.

Results

We screened Lactobacillus conditioned media from 34 infant fecal isolates for the ability to suppress C. difficile-induced IL-8 production from HT-29 cells. Factors produced by two vancomycin-resistant lactobacilli, L. rhamnosus L34 (LR-L34) and L.casei L39 (LC-L39), suppressed the secretion and transcription of IL-8 without inhibiting C. difficile viability or toxin production. Conditioned media from LR-L34 suppressed the activation of phospho-NF-κB with no effect on phospho-c-Jun. However, LC-L39 conditioned media suppressed the activation of both phospho-NF-κB and phospho-c-Jun. Conditioned media from LR-L34 and LC-L39 also decreased the production of C. difficile-induced GM-CSF in HT-29 cells. Immunomodulatory factors present in the conditioned media of both LR-L34 and LC-L39 are heat-stable up to 100°C and > 100 kDa in size.

Conclusions

Our results suggest that L. rhamnosus L34 and L. casei L39 each produce factors capable of modulating inflammation stimulated by C. difficile. These vancomycin-resistant Lactobacillus strains are potential probiotics for treating or preventing CDAD.

5-Aminosalicylic Acid Inhibits Acute Clostridium difficile Toxin A-Induced Colitis in Rats

We tested the hypothesis that 5-aminosalicylic acid (5-ASA) inhibits toxin A-induced generation of colonic leukotriene B₄ (LTB₄) and toxin A colitis in rats. Isolated colonic segments in anesthetized rats were treated intraluminally with toxin A for 3 hours with or without 30 minutes of pretreatment with either 5-ASA or sulfapyridine and then colonic tissue levels of LTB₄ were measured and inflammation was assessed. Separately, sulfasalazine was administered to rats in their drinking water for 5 days, isolated colonic segments were then prepared, toxin A was administered, and inflammation was assessed as before. Pretreatment with 5-ASA inhibited toxin A-induced increased tissue LTB₄ concentration in the colon. Sulfasalazine and 5-ASA but not sulfapyridine significantly inhibited toxin A colitis. However, pretreatment with 5-ASA did not protect against direct TRPV1-mediated colitis caused by capsaicin. Toxin A stimulated the release of substance P (SP), and this effect was also inhibited by sulfasalazine and 5-ASA but not by sulfapyridine. Thus, toxin A stimulates colonic LTB₄ resulting in activation of TRPV1, release of SP, and colitis. Inhibition of 5-LO by 5-ASA disrupts this pathway and supports the concept that LTB₄ activation of TRPV1 plays a role in toxin A colitis.

Carbohydrate-based Clostridium difficile vaccines

Clostridium difficile is responsible for thousands of deaths each year and a vaccine would be welcomed, especially one that would disrupt bacterial maintenance, colonization and persistence in carriers and convalescent patients. Structural explorations at the University of Guelph (ON, Canada) discovered that C. difficile may express three phosphorylated polysaccharides, named PSI, PSII and PSIII; this review captures our recent efforts to create vaccines based on these glycans, especially PSII, the common antigen that has precipitated immediate attention. The authors describe the design and immunogenicity of vaccines composed of raw polysaccharides and conjugates thereof. So far, it has been observed that anti-PSII antibodies can be raised in farm animals, mice and hamster models; humans and horses carry anti-PSII IgA and IgG antibodies from natural exposure to C. difficile, respectively; phosphate is an indispensable immunogenic epitope and vaccine-induced PSII antibodies recognize PSII on C. difficile outer surface.

Probiotics for the prevention of Clostridium difficile-associated diarrhea in adults and children

BACKGROUND

Antibiotics are widely prescribed; however they can cause disturbances in gastrointestinal flora which may lead to reduced resistance to pathogens such as Clostridium difficile (C. difficile). Probiotics are live organisms thought to balance the gastrointestinal flora.

OBJECTIVES

The primary objectives were to assess the efficacy and safety of probiotics for preventing Clostridium difficile-associated diarrhea (CDAD) or C. difficile infection in adults and children.

SEARCH METHODS

On February 21, 2013 we searched PubMed (1966-2013), EMBASE (1966-2013), Cochrane Central Register of Controlled Trials (The Cochrane Library 2013, Issue 1), CINAHL (1982-2013), AMED (1985-2013), and ISI Web of Science. Additionally, we conducted an extensive grey literature search including contact with industry representatives.

SELECTION CRITERIA

Randomized controlled (placebo, alternative prophylaxis, or no treatment control) trials investigating probiotics (any strain, any dose) for prevention of CDAD, or C. difficile infection were considered for inclusion.

DATA COLLECTION AND ANALYSIS

Two authors independently and in duplicate extracted data and assessed risk of bias using pre-constructed, and piloted, data extraction forms. Any disagreements were resolved by a third adjudicator. For articles published in abstract form only, further information was sought by contacting principal authors. The primary outcome was the incidence of CDAD. Secondary outcomes included the incidence of C. difficile infection, adverse events, antibiotic-associated diarrhea (AAD) and length of hospital stay. Dichotomous outcomes (e.g. incidence of CDAD) were pooled using a random-effects model to calculate the relative risk and corresponding 95% confidence interval (95% CI). Continuous outcomes (e.g. length of hospital) were pooled using a random-effects model to calculate the mean difference and corresponding 95% CI. Sensitivity analyses were conducted to explore the impact of missing data on efficacy and safety outcomes. For the sensitivity analyses, we assumed that the event rate for those participants in the control group who had missing data was the same as the event rate for those participants in the control group who were successfully followed. For the probiotic group we calculated effects using the following assumed ratios of event rates in those with missing data in comparison to those successfully followed: 1.5:1, 2:1, 3:1, and 5:1. To explore possible explanations for heterogeneity, a priori subgroup analysis were conducted on probiotic species, dose, adult versus pediatric population, and risk of bias.The overall quality of the evidence supporting each outcome was assessed using the GRADE criteria.

MAIN RESULTS

A total of 1871 studies were identified with 31 (4492 participants) meeting eligibility requirements for our review. Overall 11 studies were rated as a high risk of bias due mostly to missing outcome data. A complete case analysis (i.e. participants who completed the study) of those trials investigating CDAD (23 trials, 4213 participants) suggests that probiotics significantly reduce this risk by 64%. The incidence of CDAD was 2.0% in the probiotic group compared to 5.5% in the placebo or no treatment control group (RR 0.36; 95% CI 0.26 to 0.51). Sixteen of 23 trials had missing CDAD data ranging from 5% to 45%. These results proved robust to sensitivity analyses of plausible and worst-plausible assumptions regarding missing outcome data and were similar whether considering trials in adults versus children, lower versus higher doses, different probiotic species, or higher versus lower risk of bias. Our judgment is that the overall evidence warrants moderate confidence in this large relative risk reduction. We downgraded the overall quality of evidence for CDAD to 'moderate' due to imprecision. There were few events (154) and the calculated optimal information size (n = 8218) was more than the total sample size. With respect to the incidence of C. difficile infection, a secondary outcome, pooled complete case results from 13 trials (961 participants) did not show a statistically significant reduction. The incidence of C. difficile infection was 12.6% in the probiotics group compared to 12.7% in the placebo or no treatment control group (RR 0.89; 95% CI 0.64 to 1.24). Adverse events were assessed in 26 studies (3964 participants) and our pooled complete case analysis indicates probiotics reduce the risk of adverse events by 20% (RR 0.80; 95% CI 0.68 to 0.95). In both treatment and control groups the most common adverse events included abdominal cramping, nausea, fever, soft stools, flatulence, and taste disturbance. For the short-term use of probiotics in patients that are not immunocompromised or severely debilitated, we consider the strength of this evidence to be moderate.

AUTHORS' CONCLUSIONS

Based on this systematic review and meta-analysis of 23 randomized controlled trials including 4213 patients, moderate quality evidence suggests that probiotics are both safe and effective for preventing Clostridium difficile-associated diarrhea.

Pseudomembranous colitis in cystic fibrosis

Cystic fibrosis (CF) patients may require frequent courses of antibiotics and repeated hospital admissions. Although children with CF have high carriage rate for C.difficile, they rarely develop colitis. Pseudomembranous colitis is more common in adult post lung transplant CF patients. Although rare, paseudomembranous colitis should be considered in CF patients presenting with abdominal symptoms even in the absence of diarrhoea.

The role of acute care surgery in the treatment of severe, complicated Clostridium difficile-associated disease

Clostridium difficile associated disease (CDAD) is the result of colonic bacterial overgrowth with this gram positive anaerobic organism and the production of toxins that typically induce diarrhea. Most patients with CDAD respond to treatment with oral metronidazole or vancomycin, but a subset of patients will develop a severe systemic illness, multiple organ failure, and death. There are no reliable combinations of clinical or laboratory findings that will distinguish patients who will respond to medical therapy and those who will progress to a more complicated state. Early surgical consultation should be considered in patients with ileus, severe abdominal pain, significant tenderness, immunosuppression, advanced age, high white blood cell or band counts, acute renal failure, mental status changes, or cardiopulmonary compromise. The standard operation for fulminant colitis is subtotal colectomy but the high mortality of the operation, and the long-term morbidity even in survivors combine to act as deterrents to early surgical consultation and operation. Novel operative approaches that preserve the colon and minimize operative morbidity may prove to remove the barriers to earlier surgical treatment for fulminant CDAD and improve outcomes.

Proton pump inhibitor use and recurrent Clostridium difficile-associated disease: a case-control analysis matched by propensity score

BACKGROUND AND AIM

Clostridium difficile has been increasingly diagnosed in hospitalized patients. An association between proton pump inhibitors (PPIs) use and Clostridium difficile-associated disease (CDAD) and between recurrent CDAD has been suggested. The aim of this study is to investigate whether PPI use is associated with the development of recurrent CDAD.

METHODS

This was a retrospective case-control study of patients with CDAD at Yeungnam University Medical Center, seen from January 2004 to December 2008. C. difficile infection was diagnosed by the presence of C. difficile toxin in the stool. Those with recurrent disease were matched with nonrecurrent controls using multivariate matched sampling methods that incorporated the propensity score.

RESULTS

Recurrent CDAD developed in 28 (14.1%) of the 198 patients with diarrhea and positive C. difficile stool toxin assays. Multivariate analysis of the total population of recurrent versus nonrecurrent CDAD revealed that additional use of non-C. difficile antimicrobial therapy (concomitant with the treatment or after or both), poor response to therapy with metronidazole or vancomycin, and recent gastrointestinal surgery were risk factors for recurrent CDAD. We were able to match 21 recurrent CDAD subjects with 21 without recurrent CDAD. Among the matched patients only PPI use was associated with recurrent CDAD (ie, 47.6% vs. 4.8%, P=0.004 for recurrent vs. nonrecurrent CDAD, respectively).

CONCLUSIONS

Among the matched patient groups, only PPI therapy was associated with recurrent CDAD. Prospective studies are needed to clarify whether avoidance of PPIs or specific cotherapies will reduce the incidence of recurrent C. difficile-associated diarrhea.

The appendix may protect against Clostridium difficile recurrence

BACKGROUND & AIMS

Several risk factors have been identified for the development of recurrent Clostridium difficile infection (CDI) that alter host immunity and disrupt colonic flora. Although the function of the appendix has been debated, its active, gut-associated lymphoid tissue and biofilm production indicate potential roles in recovery from initial CDI and protection against recurrent CDI. We investigated whether the presence or absence of an appendix is associated with CDI recurrence.

METHODS

We reviewed the medical records of adult inpatients with CDI who were admitted to a tertiary-care teaching hospital from 2005 to 2007 to identify those with and without an appendix. The primary dependent variable for statistical analysis was CDI recurrence.

RESULTS

In a multivariate analysis of 11 clinical variables, the presence of an appendix was associated inversely with CDI recurrence (P < .0001; adjusted relative risk, .398). Age older than 60 years also was associated with CDI recurrence (P = .0280; adjusted relative risk, 2.44).

CONCLUSIONS

The presence of an appendix has a significant and independent, inverse association with CDI recurrence, but this finding requires validation in a prospective study. Assessing the presence or absence of an appendix might be useful in predicting CDI recurrence.

Successful use of nitazoxanide in the treatment of recurrent Clostridium difficile infection

A 78-year-old, retired Caucasian male presented in emergency room with 3 days history of progressive watery diarrhoea. Two weeks earlier, he received intravenous levofloxacin for community acquired pneumonia. The patient was diagnosed as severe Clostridium difficile infection based on clinical presentation, labs and imaging studies. The patient was initially treated with intravenous metronidazole and oral vancomycin. While awaiting subacute rehabilitation placement, the patient relapsed twice. After first recurrence the patient was treated with 2 weeks of oral nitazoxanide. After second recurrence, the patient was treated 2 weeks of nitazoxanide followed by tapering dose of vancomycin. The patient was followed and no relapse was reported at 1 year follow-up visit.

Probiotics in clostridium difficile Infection

Clostridium difficile infection (CDI) is one of the most prevalent nosocomial infections. A dramatic increase in the incidence and severity of CDI has been noted in the past decade. Current recommendations suggest metronidazole as first-line therapy in mild to moderately severe CDI and oral vancomycin in individuals with severe CDI, or when metronidazole fails or is contradicted. Alterations of the colonic microbiota, usually caused by antimicrobial therapy, seem to play a critical role in CDI pathogenesis. Probiotics are live microorganisms that confer a health benefit to the host, and have been used in CDI. Although a wide variety of probiotics have been studied, the exact role of probiotics in preventing and treating CDI is not clear. In this study, we reviewed the current literature and recommendations on the most commonly studied protiotic agents (Saccharomyces boulardii, Lactobacillus species, and probiotic mixtures) used to prevent or treat CDI. Lactobacillus-containing probiotic mixtures and S. boulardii may be effective in the prevention of CDI in high-risk antibiotic recipients but this finding is based on small, individual studies, and further, larger, well-controlled studies are needed to confirm preliminary positive findings and to better delineate the efficacy of probiotics in CDI prevention or treatment.

Prevention of endemic healthcare-associated Clostridium difficile infection: reviewing the evidence

OBJECTIVES

Clostridium difficile is the most common infectious cause of healthcare-associated diarrhea. Because of the increasing incidence and severity of endemic C. difficile infection (CDI), interventions to prevent healthcare-associated CDI are essential. We undertook a systematic review of interventions to reduce healthcare-associated CDI.

METHODS

We searched multiple computerized databases, and manually searched for relevant articles to determine which interventions are useful in preventing CDI. Studies were required to be controlled in design and to report the incidence of endemic CDI as an outcome. Data on the patient population, intervention, study design, and outcomes were abstracted and reviewed using established criteria.

RESULTS

Few randomized controlled trials exist in the area of CDI prevention. The interventions with the greatest evidence for the prevention of CDI include antimicrobial stewardship, glove use, and disposable thermometers. Environmental decontamination also may decrease CDI rates, although the level of evidence is not as strong as for the other proven interventions. Treatment of asymptomatic carriage of C. difficile is not recommended. There is insufficient evidence to make a recommendation for or against the use of probiotics. In cases of known or suspected CDI, hand hygiene with soap and water is preferred over use of waterless alcohol hand rub. Many nonrandomized trials included in our analysis used multiple interventions concurrently, making the independent role of each preventive strategy difficult to determine. We chose to include only studies that focused on endemic CDI because studies of outbreaks have used multiple strategies, making it difficult to measure the relative efficacy of each strategy. Environmental disinfection and probiotics need to be studied further to evaluate their roles in the prevention of CDI. Although there have been no studies assessing the utility of isolation and cohorting for the prevention of endemic CDI specifically, it is a widely used intervention for containment of this and other similar multidrug-resistant pathogens.

CONCLUSIONS

Antimicrobial stewardship, glove use, hand hygiene, and disposable thermometers should be routinely used for the prevention of CDI. Environmental disinfection and probiotics should be studied further for their role in reducing CDI.

Proton pump inhibitors as a risk factor for recurrence of Clostridium-difficile-associated diarrhea

AIM: To investigate the risk factors for Clostridium-difficile-associated diarrhea (CDAD) recurrence, and its relationship with proton pump inhibitors (PPIs).

METHODS: Retrospective data of 125 consecutive hospitalized patients diagnosed with CDAD between January 2006 and December 2007 were collected by medical chart review. Collected data included patient characteristics at baseline, underlying medical disease, antibiotic history before receiving a diagnosis of CDAD, duration of hospital stay, severity of CDAD, concurrent treatment with PPIs, laboratory parameters, response to CDAD therapy, and recurrence of disease within 90 d of successful treatment. Various clinical and laboratory parameters were compared in patients in whom CDAD did or did not recur.

RESULTS: Of the 125 patients (mean age, 67.6 ± 13.9 years) that developed CDAD, 98 (78.4%) did not experience recurrence (non-recurrent group) and 27 (21.6%) experienced one or more recurrences (recurrent group). Prior to the development of CDAD, 96% of the 125 patients were prescribed antibiotics, and 56 (44.8%) of the patients received PPIs. Age older than 65 years (P = 0.021), feeding via nasogastric tube (NGT) (P = 0.045), low serum albumin level (P = 0.025), and concurrent use of PPIs (P = 0.014) were found to be risk factors for CDAD recurrence by univariate analysis. However, sex, length of hospital stay, duration and type of antibiotics used, severity of disease, leukocyte count and C-reactive protein (CRP) were not associated with risk of CDAD recurrence. On multivariate analysis, the important risk factors were advanced age (> 65 years, adjusted OR: 1.32, 95% CI: 1.12-3.87, P = 0.031), low serum albumin level (< 2.5 g/dL, adjusted OR: 1.85, 95% CI: 1.35-4.91, P = 0.028), and concurrent use of PPIs (adjusted OR: 3.48, 95% CI: 1.64-7.69, P = 0.016).

CONCLUSION: Advanced age, serum albumin level < 2.5 g/dL, and concomitant use of PPIs were found to be significant risk factors for CDAD recurrence.

Clostridium difficile and the disease it causes

Clostridium difficile is a spore-forming, toxin-producing, anaerobic bacterium abundant in soils and water. Frequent and early colonization of the human intestinal flora is common and often asymptomatic. Antimicrobials given commonly disrupt the intestinal microflora and through proliferation in colon and production of toxin A and B it precipitates C. difficile infection (CDI). The enterocytic detachment and bowel inflammation provoke C. difficile-associated diarrhoea (CDAD) sometimes developing into severe pseudomembranous colitis (PMC) and paralytic ileus. Infection is acquired from an endogenous source or from spores in the environment, most easily facilitated during hospital stay. In the elderly, comorbidity, hospitalization and antimicrobial treatment present as major risk factors and the slow recolonization of the normal flora likely responsible for single or multiple recurrences of CDI (25-50%) post therapy. The key procedure for diagnosis is toxin detection from stool specimens and sometimes in combination with culture to increase sensitivity. In mild cases stopping the offending antimicrobial will lead to resolution (25%) but standard therapy still consist of either oral metronidazole or vancomycin. Alternative agents are presently being developed and fidaxomicin, as well as nitrothiazolide are promising. Furthermore, host factors like low antitoxin A levels in serum relates to increased risk of recurrence and small numbers of patients have received immunoglobulin with good results. An immunogenic toxoid vaccine has been developed and human colostrum rich in specific secretory Ig A also support the future use of immunotherapy. Today we experience a tenfold increase of CDI incidence in the western world and both epidemics and therapeutic failure of metronidazole is contributing to morbidity and mortality. The current epidemic of the C. difficile strain NAP1/027 emerging in 2002 in Canada and the USA has now spread to most parts of Europe and virulence factors like high toxin production and sporulation challenge the therapeutic situation and cause great concern among infection control workers. Excessive use of modern fluoroquinolones is thought to play an important role in facilitating this epidemic since NAP1/027 was shown to have acquired moxifloxacin resistance compared to historical strains of the same genotype. Both the current epidemic like this and other local outbreaks from resistant or virulent strains warrant culture to be routinely performed enabling susceptibility testing and typing of the pathogen. Genotyping is most commonly done today by pulse-field gel electrophoresis (PFGE) or PCR ribotyping but multilocus variable-number tandem-repeat analysis (MLVA) seems promising. Epidemiological surveillance using all these tools will help us to better understand the global spread of C. difficile.

Recurrent Clostridium difficile infection: causality and therapeutic approaches

Recurrent diarrhoea after successful treatment of the primary episode is a common complication of Clostridium difficile infection (CDI) and may be increasing in frequency. Evidence suggests that persistent alterations in the indigenous bowel flora and failure to mount an effective antibody response to C. difficile toxins are the main mechanisms whereby recurrent CDIs occur. Treatment of the first recurrence with the same agent used for the treatment of the primary episode is reasonable, but a different approach is needed for patients with multiple CDI recurrences. Prolonged, repeated courses of metronidazole are discouraged, but a practical first option in these patients is to use tapered-dose oral vancomycin followed by a pulsed-dose regimen. Other potential options include probiotic approaches, restoration of the normal flora, immunological approaches, toxin-binding approaches, and serial therapy with vancomycin followed by rifaximin. Randomised studies including a sufficient numbers of patients have not yet been conducted for the treatment of recurrent CDI and are needed to help guide the formulation of effective recommendations.

Treatment of Clostridium difficile-associated disease

Clostridium difficile infection is an increasing burden to the health care system, totaling more than $1 billion/year in the United States. Treatment of patients with C difficile infection with metronidazole or vancomycin reduces morbidity and mortality, although the number of patients that do not respond to metronidazole is increasing. Despite initial response rates of greater than 90%, 15%-30% of patients have a relapse in symptoms after successful initial therapy, usually in the first few weeks after treatment is discontinued. Failure to develop specific antibody response has recently been identified as a critical factor in recurrence. The review discusses the different management strategies for initial and recurrent symptomatic C difficile infections.

Clostridium difficile associated infection, diarrhea and colitis

A new, hypervirulent strain of Clostridium difficile, called NAP1/BI/027, has been implicated in C. difficile outbreaks associated with increased morbidity and mortality since the early 2000s. The epidemic strain is resistant to fluoroquinolones in vitro, which was infrequent prior to 2001. The name of this strain reflects its characteristics, demonstrated by different typing methods: pulsed-field gel electrophoresis (NAP1), restriction endonuclease analysis (BI) and polymerase chain reaction (027). In 2004 and 2005, the US Centers for Disease Control and Prevention (CDC) emphasized that the risk of C. difficile-associated diarrhea (CDAD) is increased, not only by the usual factors, including antibiotic exposure, but also gastrointestinal surgery/manipulation, prolonged length of stay in a healthcare setting, serious underlying illness, immune-compromising conditions, and aging. Patients on proton pump inhibitors (PPIs) have an elevated risk, as do peripartum women and heart transplant recipients. Before 2002, toxic megacolon in C. difficile-associated colitis (CDAC), was rare, but its incidence has increased dramatically. Up to two-thirds of hospitalized patients may be infected with C. difficile. Asymptomatic carriers admitted to healthcare facilities can transmit the organism to other susceptible patients, thereby becoming vectors. Fulminant colitis is reported more frequently during outbreaks of C. difficile infection in patients with inflammatory bowel disease (IBD). C. difficile infection with IBD carries a higher mortality than without underlying IBD. This article reviews the latest information on C. difficile infection, including presentation, vulnerable hosts and choice of antibiotics, alternative therapies, and probiotics and immunotherapy. We review contact precautions for patients with known or suspected C. difficile-associated disease. Healthcare institutions require accurate and rapid diagnosis for early detection of possible outbreaks, to initiate specific therapy and implement effective control measures. A comprehensive C. difficile infection control management rapid response team (RRT) is recommended for each health care facility. A communication network between RRTs is recommended, in coordination with each country’s department of health. Our aim is to convey a comprehensive source of information and to guide healthcare professionals in the difficult decisions that they face when caring for these oftentimes very ill patients.

Prospective derivation and validation of a clinical prediction rule for recurrent Clostridium difficile infection

BACKGROUND & AIMS

Prevention of recurrent Clostridium difficile infection (CDI) is a substantial therapeutic challenge. A previous prospective study of 63 patients with CDI identified risk factors associated with recurrence. This study aimed to develop a prediction rule for recurrent CDI using the above derivation cohort and prospectively evaluate the performance of this rule in an independent validation cohort.

METHODS

The clinical prediction rule was developed by multivariate logistic regression analysis and included the following variables: age>65 years, severe or fulminant illness (by the Horn index), and additional antibiotic use after CDI therapy. A second rule combined data on serum concentrations of immunoglobulin G (IgG) against toxin A with the clinical predictors. Both rules were then evaluated prospectively in an independent cohort of 89 patients with CDI.

RESULTS

The clinical prediction rule discriminated between patients with and without recurrent CDI, with an area under the curve of the receiver-operating-characteristic curve of 0.83 (95% confidence interval [CI]: 0.70-0.95) in the derivation cohort and 0.80 (95% CI: 0.67-0.92) in the validation cohort. The rule correctly classified 77.3% (95% CI: 62.2%-88.5%) and 71.9% (95% CI: 59.2%-82.4%) of patients in the derivation and validation cohorts, respectively. The combined rule performed well in the derivation cohort but not in the validation cohort (area under the curve of the receiver-operating-characteristic curve, 0.89 vs 0.62; diagnostic accuracy, 93.8% vs 69.2%, respectively).

CONCLUSIONS

We prospectively derived and validated a clinical prediction rule for recurrent CDI that is simple, reliable, and accurate and can be used to identify high-risk patients most likely to benefit from measures to prevent recurrence.

Laboratory maintenance of Clostridium difficile

Clostridium difficile is a Gram-positive, spore-forming, anaerobe and is the leading cause of antibiotic-associated diarrhea, pseudomembranous colitis, and toxic megacolon. Essential to the lifestyle of C. difficile is the ability to form a metabolically dormant spore, germinate, and grow out upon appropriate signals and elicit disease with the secretion of two toxins. To aid in the study of this organism, this unit describes the growth and maintenance of C. difficile. Included are methods to isolate C. difficile from environmental samples, grow in laboratory medium, and produce and purify spores.

Metronidazole resistance in Clostridium difficile is heterogeneous

At our institution, the prevalence of clinical isolates of Clostridium difficile with resistance to metronidazole is 6.3%. We observed that initial metronidazole MICs of 16 to 64 mg/liter against toxigenic, primary fresh C. difficile isolates, as determined by agar dilution, decreased to 0.125 mg/liter after the isolates were thawed. In this study, we examined the possibility of heterogeneous or inducible resistance. Totals of 14 metronidazole-resistant and 10 metronidazole-susceptible clinical isolates of toxigenic C. difficile were studied. The isolates were investigated for the presence of nim genes by PCR. After the isolates were thawed, susceptibility testing was done by agar dilution, by disc diffusion using a 5-mug metronidazole disc, and by the Etest method. An experiment for determining the effect of prolonged exposure to metronidazole was applied to all resistant isolates and to susceptible control strains. None of the isolates presented the nim genes. All initially metronidazole-resistant C. difficile isolates became susceptible after thawing; however, they presented slow-growing subpopulations within the inhibition zones of both the disk and the Etest strip. All metronidazole-susceptible isolates remained homogeneously susceptible by both methods. After prolonged exposure in vitro to metronidazole, no zone of inhibition was found around the 5-microg disk in any of the metronidazole-resistant isolates, and the MICs as determined by the Etest method ranged from 0.125 to >256 mg/liter, with colonies growing inside the inhibition zone. Our results indicate that (i) resistance to metronidazole was not due to the presence of nim genes, (ii) resistance to metronidazole in toxigenic C. difficile isolates is heterogeneous, and (iii) prolonged exposure to metronidazole can select for in vitro resistance. We recommend routine performance of the disk diffusion method (5-microg metronidazole disk) with primary fresh C. difficile isolates in order to ensure that metronidazole-heteroresistant populations do not go undetected.

Review article: RNA interference--potential therapeutic applications for the gastroenterologist

BACKGROUND

A new technique of gene regulation, termed RNA interference, has emerged recently. RNA interference utilizes short double-stranded RNA to inhibit selectively gene expression of complementary RNA nucleotide sequences after transcription, but prior to translation. Gastrointestinal and hepatic disorders may be particularly amenable to therapeutic RNA interference intervention because of the relative ease of delivery of drugs to the gastrointestinal tract and liver.

AIM

To examine the published literature for potential clinical uses of RNA interference in gastroenterology and speculate on future therapies for luminal disease.

METHODS

Reports were identified using PubMed and the search term 'RNA interference', focusing on therapeutic uses related to gastrointestinal and liver disease.

RESULTS

Cellular and animal models demonstrate the potential application of short-interfering RNA-based therapies for viral hepatitis and inflammatory bowel disease. With validation of specific targets and better in vivo delivery of short-interfering RNA, RNA interference may represent a new frontier for molecular-targeted therapy in gastroenterology and hepatology.

CONCLUSIONS

Short-interfering RNA provides a novel and specific means to inhibit gene expression. Translation to the clinical arena will require further definition of side-effects, off-target effects and delivery systems. Ultimately, mucosally applied or endoscopically delivered short-interfering RNA could be one of the earliest clinical uses of short-interfering RNA therapy.

Treatment strategies for recurrent and refractory Clostridium difficile-associated diarrhea

Clostridium difficile, the most common nosocomial infection of the GI tract, has become a bigger threat with the emergence of a hypervirulent strain. C. difficile-associated diarrhea (CDAD) is usually a consequence of antibiotic therapy or chemotherapy, but sporadic cases occur, and an increase in severe sporadic cases is of great concern. Epidemics of CDAD with high morbidity and mortality have been documented in the USA, Canada and Europe, making accurate diagnosis, effective therapy and strategies for prevention more important than ever. Treatment of refractory and recurrent CDAD remain therapeutic challenges. Improved treatments are needed; several new drugs are currently in trials.

[Update on Clostridium difficile infections]

PURPOSE

Clostridium difficile is an anaerobic gram positive, spore-forming bacterium which is responsible for 15-25% of antibiotic-associated diarrhea and for more than 95% of pseudomembranous colitis (PMC). This paper will review the main knowledge on C. difficile-associated infections and their recent evolution.

CURRENT KNOWLEDGE AND KEY POINTS

Since 2003, outbreaks of severe C. difficile-associated diarrhea (CDAD) have been increasingly reported in Canada and the United States. This trend is assumed to be associated with the rapid emergence and spread of a specific clone of C. difficile belonging to PCR-ribotype 027 or North American Pulsotype 1, pulsotype (NAP1). This clone is characterized by the overproduction of toxins A and B and is positive for a third toxin named binary toxin. This clone has spread in UK, in Belgium, in the Netherlands, and, more recently, in France where it has been responsible for large outbreaks mainly in northern France.

FUTURE PROSPECTS AND PROJECTS

A systematic reporting of C. difficile incidence by health facilities should enable a better assessment of this pathology in France.

Probiotics for Clostridium difficile-associated diarrhea: focus on Lactobacillus rhamnosus GG and Saccharomyces boulardii

OBJECTIVE

To review the literature on the use of probiotics to treat or prevent recurrences of Clostridium difficile-associated diarrhea (CDAD) by replacing normal gastric flora.

DATA SOURCES

PubMed (1970-March 2007) was searched using the terms probiotics, Clostridium difficile, colitis, diarrhea, prevention, and treatment.

STUDY SELECTION AND DATA EXTRACTION

Case reports, case series, and clinical trials describing the use of probiotics in the treatment or prevention of recurrences of CDAD as primary outcome were included.

DATA SYNTHESIS

A variety of controlled trials, case series, and case reports have evaluated probiotics to treat first or recurrent episodes of CDAD. In addition, a meta-analysis has been conducted to try to determine the role of probiotics in CDAD. In general, most case series and case reports have shown favorable results with Lactobacillus rhamnosus GG or Saccharomyces boulardii. However, other reports have shown lack of benefit. The meta-analysis showed that these probiotics may be useful in treating or preventing recurrences of CDAD. Nonetheless, the heterogeneity of the studies makes definite conclusions difficult. In addition, several cases of bacteremia or fungemia associated with probiotic use have been reported, particularly in the last decade. Patients most commonly affected by these complications are immunosuppressed. Unfortunately, these are also the patients more likely to have severe CDAD or are at risk for recurrences.

CONCLUSIONS

Additional experience with and study of probiotics are warranted due to numerous unanswered questions. Given the potential for complications in debilitated and immunosuppressed patients, the risks may outweigh benefits, and rational antibiotic use may be a better option to prevent a first episode or recurrence of CDAD.

Toxin A-negative, toxin B-positive Clostridium difficile

Clostridium difficile is a major cause of infectious diarrhea in hospitalized patients. Many pathogenic strains of Clostridium difficile produce two toxins TcdA and TcdB, both of which are pro-inflammatory and enterotoxic in human intestine. Clinically relevant toxin A-negative, toxin B-positive (A(-)B(+)) strains of Clostridium difficile that cause diarrhea and colitis in humans have been isolated with increasing frequency worldwide. This perspective describes these important toxin variant strains and highlights the need to use Clostridium difficile diagnostic methods that can detect both TcdA and TcdB.

Antimicrobial therapy of Clostridium difficile-associated diarrhea

Clostridium difficile-associated diarrhea (CDAD) is the most common etiologically-defined cause of hospital-acquired diarrhea. Caused by the toxins of certain strains of C difficile, CDAD represents a growing concern, with epidemic outbreaks in some hospitals where very aggressive and difficult-to-treat strains have recently been found. Incidence of CDAD varies ordinarily between 1 to 10 in every 1,000 admissions. Evidence shows that CDAD increases morbidity, length of stay, and costs. This article described the clinical manifestations of CDAD, related risk factors, considerations for confirming CDAD, antimicrobial and non-antimicrobial treatment of CDAD, and issues related to relapses. The article concludes with a discussion of recent epidemic outbreaks involving CDAD.

Probiotics and their fermented food products are beneficial for health

Probiotics are usually defined as microbial food supplements with beneficial effects on the consumers. Most probiotics fall into the group of organisms' known as lactic acid-producing bacteria and are normally consumed in the form of yogurt, fermented milks or other fermented foods. Some of the beneficial effect of lactic acid bacteria consumption include: (i) improving intestinal tract health; (ii) enhancing the immune system, synthesizing and enhancing the bioavailability of nutrients; (iii) reducing symptoms of lactose intolerance, decreasing the prevalence of allergy in susceptible individuals; and (iv) reducing risk of certain cancers. The mechanisms by which probiotics exert their effects are largely unknown, but may involve modifying gut pH, antagonizing pathogens through production of antimicrobial compounds, competing for pathogen binding and receptor sites as well as for available nutrients and growth factors, stimulating immunomodulatory cells, and producing lactase. Selection criteria, efficacy, food and supplement sources and safety issues around probiotics are reviewed. Recent scientific investigation has supported the important role of probiotics as a part of a healthy diet for human as well as for animals and may be an avenue to provide a safe, cost effective, and 'natural' approach that adds a barrier against microbial infection. This paper presents a review of probiotics in health maintenance and disease prevention.

Intravenous immunoglobulin for the treatment of severe, refractory, and recurrent Clostridium difficile diarrhea

PURPOSE

Clostridium difficile diarrhea is common in elderly patients and leads to prolonged hospitalization. Patients with severe or recurrent Clostridium difficile diarrhea have poor antitoxin antibody responses. Intravenous immunoglobulin has been advocated in these patients. This study was designed to assess the response of patients with refractory, recurrent, or severe Clostridium difficile diarrhea to intravenous immunoglobulin.

METHODS

Retrospective review (November 2003-January 2005) of 14 patients with severe, refractory, recurrent Clostridium difficile diarrhea treated with intravenous immunoglobulin (Flebogamma, 150-400 mg/kg) from 264 Clostridium difficile toxin-positive patients.

RESULTS

Median age was 79 (range, 54-91) years. Median length of symptoms before intravenous immunoglobulin was 29 (range, 3-90) days. Patients received a median of three (range, 1-5) courses of vancomycin or metronidazole before intravenous immunoglobulin. All had hypoalbuminemia (median, 22 g/l; range, 18-33) and raised C-reactive protein (median, 47 mg/l; range, 25-255) at time of infusion. The median white cell count was 15.3 x 10(9)/liters (range, 4-24). Eight patients had evidence of pancolitis on abdominal imaging, suggesting severe Clostridium difficile diarrhea. All patients tolerated intravenous immunoglobulin without side effects. Nine (64 percent) responded with bowels normalizing in a median of ten (range, 2-26) days; one patient received two doses. One patient had a partial response from two doses but died two months later after a recurrence. The other four patients died of other causes within three weeks of infusion.

CONCLUSIONS

Intravenous immunoglobulin may be effective for severe, refractory, or recurrent Clostridium difficile diarrhea after failed conventional treatment.

Management and outcomes of a first recurrence of Clostridium difficile-associated disease in Quebec, Canada

BACKGROUND

During an epidemic of Clostridium difficile-associated disease (CDAD) caused by a strain that is a hyper-producer of toxins A and B, the frequency of a first recurrence after metronidazole treatment of the initial episode doubled in 2003-2004, compared with 1991-2002.

METHODS

To examine whether administration of metronidazole as treatment for a first recurrence of CDAD remained appropriate, we reviewed data for patients with CDAD diagnosed in a hospital in Quebec, Canada, during 1991-2005, who experienced a first recurrence. The frequency of a second recurrence within 60 days after the first one was measured using Kaplan-Meier analysis. Cox regression was used for multivariate analysis.

RESULTS

A total of 463 patients had a first recurrence of CDAD, of whom 154 (33.3%) experienced a second recurrence. Independent predictors of a second recurrence were age and duration of hospitalization after the first recurrence; this latter finding suggested that many such episodes were reinfections rather than relapses. Neither choice of treatment drug (metronidazole or vancomycin) nor use of the same drug for treatment of first recurrence, as had been used during the initial episode, was associated with increased risk of a second recurrence. However, 51 patients (11.0%) developed at least 1 complication (i.e., shock, need for colectomy, megacolon, perforation, or death within 30 days) during the first recurrence. Older age, a high leukocyte count, and renal failure at first recurrence were strongly associated with a complicated CDAD.

CONCLUSIONS

Metronidazole is not inferior to vancomycin for treatment of patients with a first recurrence of CDAD, but the risk of complications with any treatment of CDAD may be higher than has previously been documented.

Intravenous immunoglobulin for resistant Clostridium difficile infection

Clostridium difficile (CD)-associated diarrhoea and colitis may relapse in up to 20% of treated patients. We present a patient who failed to respond over a 6-month period to treatment either singly or in combination with metronidazole, vancomycin, rifampicin, cholestyramine and probiotics. Her diarrhoea rapidly resolved after a 3-day course of intravenous immunoglobulin. This treatment may compensate for a failed immune response to CD toxin and should be considered for relapsing CD-associated diarrhoea where there is no response to conventional treatment strategies.