Recurrent Clostridium difficile infections: The importance of the intestinal microbiota

Clostridium difficile infections (CDI) are a leading cause of antibiotic-associated and nosocomial diarrhea. Despite effective antibiotic treatments, recurrent infections are common. With the recent emergence of hypervirulent isolates of C. difficile, CDI is a growing epidemic with higher rates of recurrence, increasing severity and mortality. Fecal microbiota transplantation (FMT) is an alternative treatment for recurrent CDI. A better understanding of intestinal microbiota and its role in CDI has opened the door to this promising therapeutic approach. FMT is thought to resolve dysbiosis by restoring gut microbiota diversity thereby breaking the cycle of recurrent CDI. Since the first reported use of FMT for recurrent CDI in 1958, systematic reviews of case series and case report have shown its effectiveness with high resolution rates compared to standard antibiotic treatment. This article focuses on current guidelines for CDI treatment, the role of intestinal microbiota in CDI recurrence and current evidence about FMT efficacy, adverse effects and acceptability.     

Clostridium difficile Infection: A Worldwide Disease

Clostridium difficile, an anaerobic toxigenic bacterium, causes a severe infectious colitis that leads to significant morbidity and mortality worldwide. Both enhanced bacterial toxins and diminished host immune response contribute to symptomatic disease. C. difficile has been a well-established pathogen in North America and Europe for decades, but is just emerging in Asia. This article reviews the epidemiology, microbiology, pathophysiology, and clinical management of C. difficile. Prompt recognition of C. difficile is necessary to implement appropriate infection control practices.     

Glucosyltransferase activity of Clostridium difficile Toxin B is essential for disease pathogenesis

Clostridium difficile TcdB harbors a glucosyltransferase that targets host Rho GTPases. However, the role of the enzyme activity in the induction of host intestinal disease has not been demonstrated. In this study, we established a mouse acute intestinal disease model by cecum injection of wild type and glucosyltransferase-deficient TcdB and a chronic model by delivering toxin intraluminally via engineered surrogate host Bacillus megaterium. We demonstrated, for the first time, that the glucosyltransferase activity of TcdB is essential for inducing disease symptoms and intestinal pathological responses that resemble human disease, highlighting the importance of targeting toxin glucosyltransferase activity for future therapy.     

Clinical Predictors of Fulminant Colitis in Patients with Clostridium difficile Infection

Background/Aim:

Clostridium difficile infection (CDI) can affect up to 8% of hospitalized patients. Twenty-five percent CDI patients may develop C. difficile associated diarrhea (CDAD) and 1–3% may progress to fulminant C. difficile colitis (FCDC). Once developed, FCDC has higher rates of complications and mortality.

Patients and Methods:

A 10-year retrospective review of FCDC patients who underwent colectomy was performed and compared with randomly selected age- and sex-matched non-fulminant CDAD patients at our institution. FCDC (n=18) and CDAD (n=49) groups were defined clinically, radiologically, and pathologically. Univariate analysis was performed using Chi-square and Student''s t test followed by multivariate logistic regression to compute independent predictors.

Results:

FCDC patients were significantly older (77 ± 13 years), presented with triad of abdominal pain (89%), diarrhea (72%), and distention (39%); 28% had prior CDI and had greater hemodynamic instability. In contrast, CDAD patients were comparatively younger (65 ± 20 years), presented with only 1 or 2 of these 3 symptoms and only 5% had prior CDI. No significant difference was noted between the 2 groups in terms of comorbid conditions, use of antibiotics, or proton pump inhibitor. Leukocytosis was significantly higher in FCDC patients (18.6 ± 15.8/mm³ vs 10.7 ± 5.2/mm³; P=0.04) and further increased until the point of surgery. Use of antiperistaltic medications was higher in FCDC than CDAD group (56% vs 22%; P=0.01).

Conclusions:

Our data suggest several clinical and laboratory features in CDI patients, which may be indicative of FCDC. These include old age (>70 years), prior CDI, clinical triad of increasing abdominal pain, distention and diarrhea, profound leukocytosis (>18,000/mm³), hemodynamic instability, and use of antiperistaltic medications.     

Clostridium difficile toxoid vaccine in recurrent C. difficile-associated diarrhea

BACKGROUND & AIMS: Recurrent C difficile -associated diarrhea (CDAD) is associated with a lack of protective immunity to C difficile toxins. A parenteral C difficile vaccine containing toxoid A and toxoid B was reported previously to be safe and immunogenic in healthy volunteers. Our aim was to examine whether the vaccine is also well tolerated and immunogenic in patients with recurrent CDAD. METHODS: Subjects received 4, 50-microg intramuscular inoculations of the C difficile vaccine over an 8-week period. Serum antitoxin antibodies were measured by ELISA, and toxin neutralizing activity was evaluated using the tissue culture cytotoxin assay. RESULTS: Three patients with multiple episodes of recurrent CDAD were vaccinated. Two of the 3 showed an increase in serum IgG antitoxin A antibodies (3-fold and 4-fold increases, respectively) and in serum IgG antitoxin B antibodies (52-fold and 20-fold, respectively). Both also developed cytotoxin neutralizing activity against toxin A and toxin B. Prior to vaccination, the subjects had required nearly continuous treatment with oral vancomycin for 7, 9, and 22 months, respectively, to treat recurrent episodes of CDAD. After vaccination, all 3 subjects discontinued treatment with oral vancomycin without any further recurrence. CONCLUSIONS: A C difficile toxoid vaccine induced immune responses to toxins A and B in patients with CDAD and was associated with resolution of recurrent diarrhea. The results of this study support the feasibility of active vaccination against C difficile and its toxins in high-risk individuals but must be validated in larger, randomized, controlled trials.     

Clostridium difficile infection worsens the prognosis of ulcerative colitis

BACKGROUND:

The impact of Clostridium difficile infections among ulcerative colitis (UC) patients is well characterized. However, there is little knowledge regarding the association between C difficile infections and postoperative complications among UC patients.

OBJECTIVE:

To determine whether C difficile infection is associated with undergoing an emergent colectomy and experiencing postoperative complications.

METHODS:

The present population-based case-control study identified UC patients admitted to Calgary Health Zone hospitals for a flare between 2000 and 2009. C difficile toxin tests ordered in hospital or 90 days before hospital admission were provided by Calgary Laboratory Services (Calgary, Alberta). Hospital records were reviewed to confirm diagnoses and to extract clinical data. Multivariate logistic regression analyses were performed among individuals tested for C difficile to examine the association between C difficile infection and emergent colectomy and diagnosis of any postoperative complications and, secondarily, an infectious postoperative complication. Estimates were presented as adjusted ORs with 95% CIs.

RESULTS:

C difficile was tested in 278 (58%) UC patients and 6.1% were positive. C difficile infection was associated with an increased risk for emergent colectomy (adjusted OR 3.39 [95% CI 1.02 to 11.23]). Additionally, a preoperative diagnosis of C difficile was significantly associated with the development of postoperative infectious complications (OR 4.76 [95% CI 1.10 to 20.63]).

CONCLUSION:

C difficile diagnosis worsened the prognosis of UC by increasing the risk of colectomy and postoperative infectious complications following colectomy. Future studies are needed to explore whether early detection and aggressive management of C difficile infection will improve UC outcomes.     

Reducing the risk of severe complications among patients with Clostridium difficile infection

BACKGROUND:

The incidence and severity of Clostridium difficile infections are increasing, and there is a need to optimize the prevention of complicated disease.

OBJECTIVE:

To identify modifiable processes of care associated with an altered risk of C difficile complications.

METHODS:

A retrospective cohort study (with prospective case ascertainment) of all C difficile infections during 2007/2008 at a tertiary care hospital was conducted.

RESULTS:

Severe complications were frequent (occurring in 97 of 365 [27%] C difficile episodes), with rapid onset (median three days postdiagnosis). On multivariable analysis, nonmodifiable predictors of complications included repeat infection (OR 2.67), confusion (OR 2.01), hypotension (OR 0.97 per increased mmHg) and elevated white blood cell count (OR 1.04 per 10⁹ cells/L). Protection from complications was associated with initial use of vancomycin (OR 0.24); harm was associated with ongoing use of exacerbating antibiotics (OR 3.02).

CONCLUSION:

C difficile infections often occur early in the disease course and are associated with high complication rates. Clinical factors that predicted a higher risk of complications included confusion, hypotension and leukocytosis. The most effective ways to improve outcomes for patients with C difficile colitis are consideration of vancomycin as first-line treatment for moderate to severe cases, and the avoidance of unnecessary antibiotics.     

Ulcerative colitis worsened after Clostridium difficile infection:Efficacy of infliximab

The incidence of Clostridium difficile(C.difficile)infection(CDI)is 1.8%-5.7%in admitted patients with ulcerative colitis(UC).CDI can worsen UC and increase the risk for colectomy or even death,thus necessitating therapy escalation,such as increasing the corticoid therapy or starting a biologic treatment.Several reported cases with infliximab therapy have provided favorable outcomes in UC patients with CDI,suggesting that infliximab treatment may be protective;however,the optimal infliximab treatment regimen for UC patients with CDI remains to be established.Here,we report a case of worsening UC in the presence of recurrent CDI.The patient had received prior ciprofloxacin and immunosuppressive therapy during a prolonged hospital stay.The deterioration in the patient’s condition likely resulted from the ability of C.difficile to promote relapsing of UC by activating the immune response.Ultimately,the patient was treated with a high dose of infliximab after a low trough level of infliximab at week 8was identified,yielding better clinical results.Infliximab was found to be safe after repetitive episodes of CDI.The trough level of infliximab was therefore a useful indicator to guide therapy and correlated well with the patient’s outcome.     

Models for the study of Clostridium difficile infection

Models of Clostridium difficile infection (C. difficile) have been used extensively for Clostridium difficile (C. difficile) research. The hamster model of C. difficile infection has been most extensively employed for the study of C. difficile and this has been used in many different areas of research, including the induction of C. difficile, the testing of new treatments, population dynamics and characterization of virulence. Investigations using in vitro models for C. difficile introduced the concept of colonization resistance, evaluated the role of antibiotics in C. difficile development, explored population dynamics and have been useful in the evaluation of C. difficile treatments. Experiments using models have major advantages over clinical studies and have been indispensible in furthering C. difficile research. It is important for future study programs to carefully consider the approach to use and therefore be better placed to inform the design and interpretation of clinical studies.     

Antibiotic prophylaxis in variceal hemorrhage: timing, effectiveness and Clostridium difficile rates

AIM:To investigate if antibiotics administered within 8 h of endoscopy reduce mortality or increase the incidence of Clostridium difficile infection(CDI).METHODS:A 2-year retrospective analysis of all patients who presented with first variceal hemorrhage was undertaken.The primary outcome measure was 28-d mortality.Secondary outcome measures were 28-d rebleeding rates and 28-d incidence of CDI.All patients were admitted to a tertiary liver unit with a consultantled,24-h endoscopy service.Patients received s...     

Clostridium difficile and inflammatory bowel disease: Role in pathogenesis and implications in treatment

Clostridium difficile(C.difficile)is the leading cause of antibiotic associated colitis and nosocomial diarrhea.Patients with inflammatory bowel disease(IBD)are at increased risk of developing C.difficile infection(CDI),have worse outcomes of CDI-including higher rates of colectomy and death,and experience higher rates of recurrence.However,it is still not clear whether C.difficile is a cause of IBD or a consequence of the inflammatory state in the intestinal environment.The burden of CDI has increased dramatically over the past decade,with severe outbreaks described in many countries,which have been attributed to a new and more virulent strain.A parallel rise in the incidence of CDI has been noted in patients with IBD.IBD patients with CDI tend be younger,have less prior antibiotic exposure,and most cases of CDI in these patients represent outpatient acquired infections.The clinical presentation of CDI in these patients can be unique-including diversion colitis,enteritis and pouchitis,and typical findings on colonoscopy are often absent.Due to the high prevalence of CDI in patients hospitalized with an IBD exacerbation,and the prognostic implications of CDI in these patients,it is recommended to test all IBD patients hospitalized with a disease flare for C.difficile.Treatment includes general measures such as supportive care and infection control measures.Antibiotic therapy with either oral metronidazole,vancomycin,or the novel antibiotic-fidaxomicin,should be initiated as soon as possible.Fecal macrobiota transplantation constitutes another optional treatment for severe/recurrent CDI.The aim of this paper is to review recent data on CDI in IBD:role in pathogenesis,diagnostic methods,optional treatments,and outcomes of these patients.     

Incidence and Clinical Outcomes of Clostridium difficile Infection after Treatment with Tuberculosis Medication

Background/Aims

To determine the incidence and clinical characteristics of tuberculosis (TB) medication-associated Clostridium difficile infection.

Methods

This multicenter study included patients from eight tertiary hospitals enrolled from 2008 to 2013. A retrospective analysis was conducted to identify the clinical features of C. difficile infection in patients who received TB medication.

Results

C. difficile infection developed in 54 of the 19,080 patients prescribed TB medication, representing a total incidence of infection of 2.83 cases per 1,000 adults. Fifty-one of the 54 patients (94.4%) were treated with rifampin. The patients were usually treated with oral metronidazole, which produced improvement in 47 of the 54 patients (87%). Twenty-three patients clinically improved with continuous rifampin therapy for C. difficile infection. There were no significant differences in improvement between patients treated continuously (n=21) and patients in whom treatment was discontinued (n=26).

Conclusions

The incidence of C. difficile infection after TB medication was not low considering the relatively low TB medication dosage compared to other antibiotics. It may not be always necessary to discontinue TB medication. Instead, decisions concerning discontinuation of TB medication should be based on TB status.     

Hematologic diseases: High risk of Clostridium difficile associated diarrhea

AIM:To investigate the incidence and clinical outcome of Clostridium difficile(C.difficile)associated diarrhea(CDAD)in patients with hematologic disease.METHODS:We retrospectively reviewed the medical records of patients who underwent C.difficile testing in a tertiary hospital in 2011.The incidence and risk factors for CDAD and its clinical course including recurrence and mortality were assessed in patients with hematologic disease and compared with those in patients with nonhematologic disease.RESULTS:About 320 patients were diagnosed with CDAD(144 patients with hematologic disease;176with nonhematologic disease).The incidence of CDAD in patients with hematologic disease was estimated to be 36.7 cases/10000 patient hospital days,which was higher than the 5.4 cases/10000 patient hospital days in patients with nonhematologic disease.Recurrence of CDAD was more frequent in patients with hematologic disease compared to those with nonhematologic disease(18.8%vs 8.5%,P<0.01),which was associated with higher re-use of causative antibiotics for CDAD.Mortality due to CDAD did not differ between the two groups.Multivariate analysis showed that intravenous immunoglobulin was the only significant factor associated with a lower rate of recurrence of CDAD in patients with hematologic disease.CONCLUSION:The incidence and recurrence of CDAD was higher in patients with hematologic disease than in those with nonhematologic disease.     

Clostridium difficile in children: colonisation and disease

Clostridium difficile is the commonest cause of hospital acquired diarrhoea in adults and is associated with significant mortality and morbidity. The clinical significance of C. difficile in children, however, is less certain. In this article we discuss colonisation and infection and describe C. difficile in childhood in terms of risk factors, epidemiology and management.     

The value of repeat Clostridium difficile toxin testing during and after an outbreak of C difficile-associated diarrhea

BACKGROUND:

The recent increase in Clostridium difficile-associated diarrhea (CDAD) has led to questions about the reproducibility and sensitivity of C difficile toxin testing (CDTT). While there have been recommendations to repeat CDTT following a negative result, previous studies have failed to show a benefit. However, no studies were performed during an outbreak of CDAD. The value of repeat CDTT after an initial negative result in patients tested during and after an outbreak of CDAD is reported in the present study, as well as the reproducibility of CDTT when multiple samples are received and tested on the same day.

METHODS:

The results of CDTT, performed using a cell cytotoxicity assay between April 1, 2001, and March 31, 2008, were retrieved and searched for patients who had repeat samples tested after an initial negative result. The result and the number of days after a negative result were determined using the date of the most recent negative test. The cumulative positivity rate was calculated by adding all of the repeat positive test results for the days in question and dividing by the total number of tests performed during that time.

RESULTS:

A total of 8661 patients submitted 14,991 stool specimens for CDTT during the study period. There were 3095 samples that tested positive (20.6%) for the toxin. The results were divided into two time periods to reflect the CDAD outbreak, which began in April 2002: period 1 (outbreak) was from April 1, 2002, to March 31, 2006, and period 2 was from April 1, 2006, to March 31, 2008. The rate of positivity was 24.2% during period 1, and 11.6% during period 2 (P<0.001). Repeat CDTT was performed 619 times on samples received on the same day as the initial specimen, and only three (0.5%) were discordant. A total of 1630 samples were retested within one to seven days of a negative result, and 103 (6.3%) tested positive (7.8% period 1 and 2.9% period 2; P=0.002). The likelihood of a positive result on repeat testing in the first three days after a negative result was low (0.9%, 7% and 4%, respectively). The cumulative positivity for repeat testing performed in the first three days was 0.9%, 3.3% and 3.5%, respectively, and did not differ significantly at day 3 during the period of high CDTT positivity (P=0.110).

CONCLUSIONS:

The value of repeat CDTT, performed using a cell cytotoxicity assay, was low in the first three days after an initial negative result and was unchanged during a CDAD outbreak.     

A cohort study for the derivation and validation of a clinical prediction scale for hospital-onset Clostridium difficile infection

OBJECTIVE:

To develop and validate a clinical prediction scale for hospital-onset Clostridium difficile infection (CDI).

METHODS:

A community-based, 360-bed hospital located in the suburbs of a metropolitan area in the United States served as the setting for the present retrospective cohort study. The cohort consisted of patients admitted to the adult medical service over a six-year period from October 2005 to September 2011. The cohort was divided into derivation (October 2005 to September 2009) and validation (October 2009 to September 2011) groups. The primary outcome measure was hospital-onset CDIs identified as stool positive for C difficile after 48 h of hospital admission ordered for new-onset unformed stool by the treating physician.

RESULTS:

In the derivation phase, 35,588 patients were admitted to the medical service and 21,541 stayed in hospital beyond 48 h. A total of 266 cases of CDI were identified, 121 of which were hospital onset. The developed clinical prediction scale included the onset of unformed stool (5 points), length of hospital stay beyond seven days (4 points), age >65 years (3 points), long-term care facility residence (2 points), high-risk antibiotic use (1 point) and hypoalbuminemia (1 point). The scale had an area under the receiver operating curve (AUC) of 0.93 (95% CI 0.82 to 0.94) in predicting hospital-onset CDI, with a sensitivity of 0.94 (95% CI 0.88 to 0.97) and a specificity of 0.80 (95% CI 0.79 to 0.80) at a cut-off score of 9 on the scale. During the validation phase, 16,477 patients were admitted, of whom 10,793 stayed beyond 48 h and 58 acquired CDI during hospitalization. The predictive performance of the score was maintained in the validation cohort (AUC 0.95 [95% CI 0.93 to 0.96]) and the goodness-to-fit model demonstrated good calibration.

CONCLUSION:

The authors developed and validated a simple clinical prediction scale for hospital-onset CDI. This score can be used for periodical evaluation of hospitalized patients for early initiation of contact precautions and empirical treatment once it is validated externally in a prospective manner.     

The interplay between microbiome dynamics and pathogen dynamics in a murine model of Clostridium difficile Infection

Clostridium difficile infection (CDI) arises in the setting of antibiotic administration where disruption of the normal indigenous gut microbiota leads to susceptibility to C. difficile colonization and colitis. Using a murine model of CDI, we demonstrate that changes in the community structure of the indigenous gut microbiota are associated with the loss of colonization resistance against C. difficile. Several antibiotic regimens were tested in combination for the ability to overcome colonization resistance, including a five antibiotic cocktail consisting of kanamycin, gentamicin, colistin, metronidazole, and vancomycin administered in drinking water for three days, a single intraperitoneal dose of clindamycin or 10 days of cefoperazone in drinking water. Following antibiotic treatment animals were challenged with 105 colony forming units of C. difficile strain VPI 10463 via oral gavage. Animals that received the antibiotic cocktail and clindamycin prior to C. difficile challenge followed one of two clinical courses, either becoming clinically ill and moribund within 2-4 days post challenge, or remaining clinically well. Animals that became clinically ill developed histologically severe colitis. These histopathologic findings were significantly less severe in animals that remained clinically well. Analysis of 16S rRNA gene sequences retrieved from gut tissue at necropsy demonstrated that Proteobacteria dominated the gut microbiota in clinically ill animals. In contrast, the gut microbial community of clinically well animals more closely resembled untreated animals, which were dominated by members of the Firmicutes. All animals that received cefoperazone treatment prior to C. difficile challenge were clinically ill and moribund by 2-5 days post challenge in a dose dependent manner. The gut communities in these animals were dominated by C.difficile suggesting that cefoperazone treatment resulted in a greater loss in colonization resistance. Thus, the severity of colitis that arises in this system reflects the interplay between the expansion of C. difficile in the gut community and the ecologic dynamics of the indigenous microbial community as it recovers from antibiotic perturbation. We demonstrate that altering the balance of these two opposing processes alters clinical outcome and thus may lead to novel preventative and therapeutic approaches for CDI.