Diagnosis and treatment of Clostridium difficile in adults: a systematic review

Is Follow-Up Testing with the FilmArray Gastrointestinal Multiplex PCR Panel Necessary?

The FilmArray gastrointestinal (GI) panel (BioFire Diagnostics, Salt Lake City, UT) is a simple, sample-to-answer, on-demand, multiplex, nucleic acid amplification test for syndromic diagnosis of infectious gastroenteritis. The aim of this study was to measure the yield of follow-up testing with FilmArray GI panel within 4 weeks of an initial test. Consecutive adult and pediatric patients tested at an academic institution between August 2015 and June 2016 were included in this study. Of 145 follow-up tests in 106 unique patients with an initial negative result, 134 (92.4%) tests and 98 (92.5%) patients remained negative upon follow-up testing. Excluding targets that are not reported at this institution (Clostridium difficile, enteroaggregative Escherichia coli, enteropathogenic E. coli, and enterotoxigenic E. coli), 137 (94.5%) follow-up tests and 101 (95.3%) patients remained negative. Weekly conversion rates were not significantly different across the 4-week follow-up interval. No epidemiological or clinical factors were significantly associated with a negative to positive conversion. Of 80 follow-up tests in patients with an initial positive result, 43 (53.8%) remained positive for the same target, 34 (42.5%) were negative, and 3 were positive for a different target (3.8%). Follow-up testing with FilmArray GI panel within 4 weeks of a negative result rarely changed the initial result, and the follow-up test reverted to negative less than half the time after an initial positive result. In the absence of clinical or epidemiological evidence for a new infection, follow-up testing should be limited and FilmArray GI panel should not be used as a test of cure.

Microbiota Transfer Therapy alters gut ecosystem and improves gastrointestinal and autism symptoms: an open-label study

BACKGROUND

Autism spectrum disorders (ASD) are complex neurobiological disorders that impair social interactions and communication and lead to restricted, repetitive, and stereotyped patterns of behavior, interests, and activities. The causes of these disorders remain poorly understood, but gut microbiota, the 1013 bacteria in the human intestines, have been implicated because children with ASD often suffer gastrointestinal (GI) problems that correlate with ASD severity. Several previous studies have reported abnormal gut bacteria in children with ASD. The gut microbiome-ASD connection has been tested in a mouse model of ASD, where the microbiome was mechanistically linked to abnormal metabolites and behavior. Similarly, a study of children with ASD found that oral non-absorbable antibiotic treatment improved GI and ASD symptoms, albeit temporarily. Here, a small open-label clinical trial evaluated the impact of Microbiota Transfer Therapy (MTT) on gut microbiota composition and GI and ASD symptoms of 18 ASD-diagnosed children.

RESULTS

MTT involved a 2-week antibiotic treatment, a bowel cleanse, and then an extended fecal microbiota transplant (FMT) using a high initial dose followed by daily and lower maintenance doses for 7-8 weeks. The Gastrointestinal Symptom Rating Scale revealed an approximately 80% reduction of GI symptoms at the end of treatment, including significant improvements in symptoms of constipation, diarrhea, indigestion, and abdominal pain. Improvements persisted 8 weeks after treatment. Similarly, clinical assessments showed that behavioral ASD symptoms improved significantly and remained improved 8 weeks after treatment ended. Bacterial and phagedeep sequencing analyses revealed successful partial engraftment of donor microbiota and beneficial changes in the gut environment. Specifically, overall bacterial diversity and the abundance of Bifidobacterium, Prevotella, and Desulfovibrio among other taxa increased following MTT, and these changes persisted after treatment stopped (followed for 8 weeks).

CONCLUSIONS

This exploratory, extended-duration treatment protocol thus appears to be a promising approach to alter the gut microbiome and virome and improve GI and behavioral symptoms of ASD. Improvements in GI symptoms, ASD symptoms, and the microbiome all persisted for at least 8 weeks after treatment ended, suggesting a long-term impact.

TRIAL REGISTRATION

This trial was registered on the ClinicalTrials.gov, with the registration number  NCT02504554.

Australasian Society of Infectious Diseases updated guidelines for the management of Clostridium difficile infection in adults and children in Australia and New Zealand

The incidence of Clostridium difficile infection (CDI) continues to rise, whilst treatment remains problematic due to recurrent, refractory and potentially severe nature of disease. The treatment of C. difficile is a challenge for community and hospital-based clinicians. With the advent of an expanding therapeutic arsenal against C. difficile since the last published Australasian guidelines, an update on CDI treatment recommendations for Australasian clinicians was required. On behalf of the Australasian Society of Infectious Diseases, we present the updated guidelines for the management of CDI in adults and children.

Evaluation of the novel artus C. difficile QS-RGQ, VanR QS-RGQ and MRSA/SA QS-RGQ assays for the laboratory diagnosis of Clostridium difficile infection (CDI), and for vancomycin-resistant enterococci (VRE) and methicillin-resistant Staphylococcus aureus (MRSA) screening

Clostridium difficile, methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) are worldwide prevalent healthcare-associated pathogens. We have evaluated three Qiagen artus QS-RGQ assays for the detection of these pathogens. We examined 200 stool samples previously tested for C. difficile infection (CDI), 94 rectal swabs previously screened for VRE and 200 MRSA screening nasal swabs. With the routine diagnostic laboratory results being adopted as the gold standard, the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the artus C. difficile assay were 100%, for the artus VanR QS-RGQ assay, 95, 68, 44 and 98%, and for the artus MRSA/SA assay, 80, 94, 93 and 83%, respectively. The artus VanR assay detected the vanA and/or vanB genes in 32% of culture-negative VRE screens; in 71% of these cases, only vanB was detected. An over-estimation of the rate of faecal VRE colonisation could be due to a patient population with high rates of faecal carriage of non-enterococcal species carrying vanB. Based on our findings, we conclude that all three artus QS-RGQ assays could be a useful addition to a diagnostic laboratory, and that the optimal choice of assay should be determined according to user needs.

Antibiotic Treatment of Hospitalized Patients with Pneumonia Complicated by Clostridium Difficile Infection

Clostridium difficile infection (CDI) is one of the most common gastrointestinal complication after antimicrobial treatment. It is estimated that CDI after pneumonia treatment is connected with a higher mortality than other causes of hospitalization. The aim of the study was to assess the relationship between the kind of antibiotic used for pneumonia treatment and mortality from post-pneumonia CDI. We addressed the issue by examining retrospectively the records of 217 patients who met the diagnostic criteria of CDI. Ninety four of those patients (43.3 %) came down with CDI infection after pneumonia treatment. Fifty of the 94 patients went through severe or severe and complicated CDI. The distribution of antecedent antibiotic treatment of pneumonia in these 50 patients was as follows: ceftriaxone in 14 (28 %) cases, amoxicillin with clavulanate in 9 (18 %), ciprofloxacin in 8 (16.0 %), clarithromycin in 7 (14 %), and cefuroxime and imipenem in 6 (12 %) each. The findings revealed a borderline enhancement in the proportion of deaths due to CDI in the ceftriaxone group compared with the ciprofloxacin, cefuroxime, and imipenem groups. The corollary is that ceftriaxone should be shunned in pneumonia treatment. The study demonstrates an association between the use of a specific antibiotic for pneumonia treatment and post-pneumonia mortality in patients who developed CDI.

Effect of an antimicrobial stewardship intervention on outcomes for patients with Clostridium difficile infection

BACKGROUND

Although antimicrobial stewardship programs (ASPs) are uniquely positioned to improve treatment of Clostridium difficile infection (CDI) through targeted interventions, studies to date have not rigorously evaluated the influence of ASP involvement on clinical outcomes attributed to CDI.

METHODS

We performed a quasiexperimental study of adult patients with CDI before (n = 307) and after (n = 285) a real-time ASP review was initiated. In the intervention group, an ASP pharmacist was notified of positive CDI results and consulted with the care team to initiate optimal therapy, minimize concomitant antibiotic and acid-suppressive therapy, and recommend surgical/infectious diseases consultation in complicated cases. The primary outcome was a composite of attributable 30-day mortality, intensive care unit admission, colectomy/ileostomy, and recurrence.

RESULTS

A higher percentage of patients in the ASP intervention group had acid-suppressive therapy discontinued (30% vs 13%; P < .01). Among patients with severe CDI, more patients in the intervention group received an infectious diseases consultation (17% vs 10%; P = .04), received appropriate therapy with oral vancomycin (87% vs 59%; P <.01), and vancomycin was initiated earlier (mean, 1.1 vs 1.7 days; P <.01). Incidence of the composite outcome was not significantly different between the 2 groups (12.3% vs 14.7%; P = .40).

CONCLUSIONS

ASP review and intervention improved CDI process measures. A decrease in composite outcomes was not found, which may be due to low baseline rates of attributable complications in our institution.

An institutional comparison of total abdominal colectomy and diverting loop ileostomy and colonic lavage in the treatment of severe, complicated Clostridium difficile infections

BACKGROUND

Total abdominal colectomy (TAC) is the standard surgical treatment of Clostridium difficile infection (CDI). An alternative therapy, loop ileostomy and colonic lavage (IL), was described in 2011, but the results have never been validated.

METHODS

Patients treated surgically for CDI between April 2011 and June 2015 were included. Bivariable analysis was used to compare 30-day mortality, 1-year mortality, CDI recurrence, colon preservation and ileostomy reversal.

RESULTS

Ten IL patients and thirteen TAC patients were identified. 30-day mortality (30% vs 23%, p = 1.0) and 1-year mortality (40% vs 46%, p = 1.0) were similar. Four IL and three TAC patients (57% vs 30%, p = 0.35) experienced recurrent CDI. All six surviving IL patients had successful colon preservation; five underwent ileostomy reversal compared to three in the TAC group (83% vs 43%, p = 0.27).

CONCLUSIONS

Although IL allowed colon preservation and return of intestinal continuity in most patients, IL did not decrease mortality or recurrent CDI when compared to TAC.

Structural Insights into Substrate Recognition by Clostridium difficile Sortase

Sortases function as cysteine transpeptidases that catalyze the covalent attachment of virulence-associated surface proteins into the cell wall peptidoglycan in Gram-positive bacteria. The substrate proteins targeted by sortase enzymes have a cell wall sorting signal (CWSS) located at the C-terminus. Up to date, it is still not well understood how sortases with structural resemblance among different classes and diverse species of bacteria achieve substrate specificity. In this study, we focus on elucidating the molecular basis for specific recognition of peptide substrate PPKTG by Clostridium difficile sortase B (Cd-SrtB). Combining structural studies, biochemical assays and molecular dynamics simulations, we have constructed a computational model of Cd-SrtB_ΔN26-PPKTG complex and have validated the model by site-directed mutagensis studies and fluorescence resonance energy transfer (FRET)-based assay. Furthermore, we have revealed that the fourth amino acid in the N-terminal direction from cleavage site of PPKTG forms specific interaction with Cd-SrtB and plays an essential role in configuring the peptide to allow more efficient substrate-specific cleavage by Cd-SrtB.

The Use and Efficacy of Fecal Microbiota Transplantation for Refractory Clostridium difficile in Patients with Inflammatory Bowel Disease

Clostridium difficile (CD) is an anaerobic, spore-forming bacillus that is responsible for a spectrum of gastrointestinal illness ranging from asymptomatic carriage to toxic megacolon and death. The prevalence of CD infection is increasing in both hospitalized and community-based inflammatory bowel disease populations. Standard antibiotic therapy fails to cure or prevent recurrence in more than 50% of patients, thus increasing the need for alternative therapies. Recently, fecal microbiota transplantation has received renewed attention as a therapy for refractory or recurrent CD infection. A high success rate combined with a favorable safety profile makes this therapy an attractive option for patients who have failed standard antibiotic therapy. Increasingly, this therapy is used in patients with CD infection and inflammatory bowel disease, as the combination of active inflammation and toxin-producing CD provides a challenging mix for clinicians.

Utilization of Health Services Among Adults With Recurrent Clostridium difficile Infection: A 12-Year Population-Based Study

BACKGROUND Considerable efforts have been dedicated to developing strategies to prevent and treat recurrent Clostridium difficile infection (rCDI); however, evidence of the impact of rCDI on patient healthcare utilization and outcomes is limited. OBJECTIVE To compare healthcare utilization and 1-year mortality among adults who had rCDI, nonrecurrent CDI, or no CDI. METHODS We performed a nested case-control study among adult Kaiser Foundation Health Plan members from September 1, 2001, through December 31, 2013. We identified CDI through the presence of a positive laboratory test result and divided patients into 3 groups: patients with rCDI, defined as CDI in the 14-57 days after initial CDI; patients with nonrecurrent CDI; and patients who never had CDI. We conducted 3 matched comparisons: (1) rCDI vs no CDI; (2) rCDI vs nonrecurrent CDI; (3) nonrecurrent CDI vs no CDI. We followed patients for 1 year and compared healthcare utilization between groups, after matching patients on age, sex, and comorbidity. RESULTS We found that patients with rCDI consistently have substantially higher levels of healthcare utilization in various settings and greater 1-year mortality risk than both patients who had nonrecurrent CDI and patients who never had CDI. CONCLUSIONS Patients who develop an initial CDI are generally characterized by excess underlying, severe illness and utilization. However, patients with rCDI experience even greater adverse consequences of their disease than patients who do not experience rCDI. Our results further support the need for continued emphasis on identifying and using novel approaches to prevent and treat rCDI. Infect Control Hosp Epidemiol. 2016;1-8.

A High Rate of Alternative Diagnoses in Patients Referred for Presumed Clostridium difficile Infection

GOALS

We evaluated a cohort of patients referred to our center for presumed recurrent Clostridium difficile infection (CDI) to determine final diagnoses and outcomes.

BACKGROUND

As rates of CDI have increased, more patients are diagnosed with recurrent CDI and other sequelae of the infection. Distinguishing symptomatic patients with CDI from those who are colonized with an alternative etiology of diarrheal symptoms may be challenging.

MATERIALS AND METHODS

We performed a retrospective review of 117 patients referred to our center for recurrent CDI between January 2013 and June 2014. Data collected included demographics, the referring provider, previous anti-CDI treatment, and significant medical conditions. In addition, we gathered data on atypical features of CDI and investigations obtained to investigate the etiology of symptoms. Outcomes included rates of alternative diagnoses and the accuracy of CDI diagnosis by the referral source.

RESULTS

The mean age was 61 years, and 70% were female. About 29 patients (25%) were determined to have a non-CDI diagnosis. Most common alternative diagnoses included irritable bowel syndrome (18 patients: 62%) and inflammatory bowel disease (3 patients:10%). The age was inversely correlated with the rate of non-CDI diagnosis (P=0.016). Of the remaining 88 (75%) patients with a confirmed diagnosis of CDI, 25 (28%) received medical therapy alone and 63 (72%) underwent fecal microbiota transplantation.

CONCLUSIONS

Among patients referred to our center for recurrent CDI, a considerable percentage did not have CDI, but rather an alternative diagnosis, most commonly irritable bowel syndrome. The rate of alternative diagnosis correlated inversely with age. Providers should consider other etiologies of diarrhea in patients presenting with features atypical of recurrent CDI.

New antibiotic strategies in patients with cirrhosis and bacterial infection

Early diagnosis and adequate empirical antibiotic treatment of bacterial infections in advanced cirrhosis is essential to improve outcomes given the high risk of developing severe sepsis, multiple organ failure and death. β-lactams and quinolones are nowadays frequently ineffective in nosocomial and healthcare associated infections, due to the increasing prevalence of multidrug resistant (MDR) bacteria reported across different geographical areas. Recent antibiotic exposure also increases the risk of developing MDR bacterial infections. Initial antibiotic strategies should therefore be tailored according to the presence or absence of risk factors of MDR bacteria and to the severity of infection and should consider the local epidemiology. Empirical treatment in the population at high risk of MDR bacterial infections requires the use of broad-spectrum antibiotics (carbapenems or tigecycline) and of drugs active against specific resistant bacteria (glycopeptides, linezolid, daptomycin, amikacin, colistin). Early de-escalation policies are recommended to prevent the spread of MDR bacteria in cirrhosis.

Infectious Complications during Tandem High-Dose Chemotherapy and Autologous Stem Cell Transplantation for Children with High-Risk or Recurrent Solid Tumors

We retrospectively analyzed infectious complications during tandem high-dose chemotherapy and autologous stem cell transplantation (HDCT/auto-SCT) in children and adolescents with high-risk or recurrent solid tumors. A total of 324 patients underwent their first HDCT/auto-SCT between October 2004 and September 2014, and 283 of them proceeded to their second HDCT/auto-SCT (a total of 607 HDCT/auto-SCTs). During the early transplant period of 607 HDCT/auto-SCTs (from the beginning of HDCT to day 30 post-transplant), bacteremia, urinary tract infection (UTI), respiratory virus infection, and varicella zoster virus (VZV) reactivation occurred in 7.1%, 2.3%, 13.0%, and 2.5% of HDCT/auto-SCTs, respectively. The early transplant period of the second HDCT/auto-SCT had infectious complications similar to the first HDCT/auto-SCT. During the late transplant period of HDCT/auto-SCT (from day 31 to 1 year post-transplant), bacteremia, UTI, and VZV reactivation occurred in 7.5%, 2.5%, and 3.9% of patients, respectively. Most infectious complications in the late transplant period occurred during the first 6 months post-transplant. There were no invasive fungal infections during the study period. Six patients died from infectious complications (4 from bacterial sepsis and 2 from respiratory virus infection). Our study suggests that infectious complications are similar following second and first HDCT/auto-SCT in children.

Evaluation of the performance of C. DIFF QUIK CHEK COMPLETE and its usefulness in a hospital setting with a high prevalence of Clostridium difficile infection

Rapid and accurate diagnosis of Clostridium difficile infection (CDI) is crucial for patient care, infection control, and efficient surveillance. We evaluated C. DIFF QUIK CHEK COMPLETE (QCC; TechLab), which detects glutamate dehydrogenase (GDH) antigen (QCC-Ag) and toxin A/B (QCC-Tox) simultaneously, and compared it to the laboratory diagnostics for CDI currently in use in a tertiary hospital setting with a high prevalence of CDI. QCC, RIDASCREEN C. difficile toxin A/B assay (Toxin EIA; R-Biopharm AG), chromID C. difficile agar (bioMérieux) culture (ChromID culture), and Xpert C. difficile PCR assay (Xpert PCR; Cepheid) were performed according to the manufacturers' instructions. Performances of the assays were compared against that of Xpert PCR as a reference. Of the 231 loose stool specimens, 83 (35.9%) were positive by Xpert PCR. The sensitivity, specificity, and positive and negative predictive values were 97.6%, 93.9%, 90.0%, and 98.6%, respectively, for QCC-Ag and 55.4%, 100%, 100%, and 80.0%, respectively, for QCC-Tox. The median threshold cycle values of the QCC-Tox(+) specimens were lower than those of the QCC-Tox(-) specimens. Results of QCC as an initial screening test were confirmed in 81.0% (187/231) of samples; these specimens did not require further testing. QCC is a rapid, easy, and cost-effective method that would be a useful first-line screening assay for laboratory diagnosis of CDI in a tertiary hospital with a high prevalence of CDI. A two-step algorithm using QCC as an initial screening tool, followed by Xpert PCR as a confirmatory test, is a practical and cost-effective approach.

Oral, frozen fecal microbiota transplant (FMT) capsules for recurrent Clostridium difficile infection

BACKGROUND

Fecal microbiota transplantation (FMT) has been shown to be safe and effective in treating refractory or relapsing C. difficile infection (CDI), but its use has been limited by practical barriers. We recently reported a small preliminary feasibility study using orally administered frozen fecal capsules. Following these early results, we now report our clinical experience in a large cohort with structured follow-up.

METHODS

We prospectively followed a cohort of patients with recurrent or refractory CDI who were treated with frozen, encapsulated FMT at our institution. The primary endpoint was defined as clinical resolution whilst off antibiotics for CDI at 8 weeks after last capsule ingestion. Safety was defined as any FMT-related adverse event grade 2 or above.

RESULTS

Overall, 180 patients aged 7-95 years with a minimal follow-up of 8 weeks were included in the analysis. CDI resolved in 82 % of patients after a single treatment, rising to a 91 % cure rate with two treatments. Three adverse events Grade 2 or above, deemed related or possibly related to FMT, were observed.

CONCLUSIONS

We confirm the effectiveness and safety of oral administration of frozen encapsulated fecal material, prepared from unrelated donors, in treating recurrent CDI. Randomized studies and FMT registries are still needed to ascertain long-term safety.

Rapid detection of Clostridium difficile toxins and laboratory diagnosis of Clostridium difficile infections

BACKGROUND

Clostridium difficile is an anaerobic, spore-forming and Gram-positive bacillus. It is the major cause of antibiotic-associated diarrhea prevailing in hospital settings. The morbidity and mortality of C. difficile infection (CDI) has increased significantly due to the emergence of hypervirulent strains. Because of the poor clinical different between CDI and other causes of hospital-acquired diarrhea, laboratory test for C. difficile is an important intervention for diagnosis of CDI.

OBJECTIVE

Laboratory tests for CDI can broadly detect either the organisms or its toxins. Currently, several laboratory tests are used for diagnosis of CDI, including toxigenic culture, glutamate dehydrogenase detection, nucleic acid amplification testing, cell cytotoxicity assay, and enzyme immunoassay towards toxin A and/or B. This review focuses on the rapid testing of C. difficile toxins and currently available methods for diagnosis of CDI, giving an overview of the role that the toxins rapid detecting plays in clinical diagnosis of CDI.

Challenges in management of recurrent and refractory Clostridium difficile infection

Clostridium difficile infection (CDI) is the most common nosocomial infection in the United States and is associated with a high mortality. One quarter of patients treated for CDI have at least one recurrence. Spore persistence, impaired host immune response and alteration in the gastrointestinal microbiome due to antibiotic use are factors in recurrent disease. We review the etiology of recurrent CDI and best approaches to management including fecal microbiota transplantation.

Performance of the artus C. difficile QS-RGQ Kit for the detection of toxigenic Clostridium difficile

OBJECTIVES

Nucleic acid amplification tests are commonly used for the direct detection of toxigenic Clostridium difficile. We evaluated the diagnostic performance of newly launched, artus C. difficile QS-RGQ Kit (artus C. difficile, QIAGEN, Hilden, Germany), in comparison with toxigenic culture (TC) and Xpert C. difficile (Cepheid, Sunnyvale, CA, USA).

DESIGN AND METHODS

In prospectively collected 261 diarrheal specimens, the artus C. difficile and the Xpert C. difficile assays were performed. TC using chromogenic agar (chromID CD agar, bioMérieux, Marcy-l'Etoile, France) was used a reference method.

RESULTS

Based on TC, the sensitivity and specificity of the artus C. difficile were 98.2% and 93.6%, respectively, and those of the Xpert C. difficile were 94.6% and 94.6%, respectively; there was no statistical difference. The agreement between the artus C. difficile and the Xpert C. difficile was almost perfect (kappa=0.918). In the artus C. difficile, the cycle threshold (Ct) values of tcdA were constantly lower than those of tcdB in all positive specimens (mean Ct, 24.5 vs. 26.4; mean difference of 1.9). Three specimens were considered tcdA+/tcdB- by the difference of Ct cutoffs between tcdA and tcdB (38.3 and 36.5, respectively).

CONCLUSIONS

The performance of the artus C. difficile is excellent compared with TC and is comparable to that of the Xpert C. difficile. Both PCR assays could be useful diagnostic options for the direct detection of toxigenic C. difficile in clinical laboratories. The optimal Ct cutoff of tcdA and tcdB for artus C. difficile may be further validated in following studies.

Comparison of Diagnostic Algorithms for Detecting Toxigenic Clostridium difficile in Routine Practice at a Tertiary Referral Hospital in Korea

Since every single test has some limitations for detecting toxigenic Clostridium difficile, multistep algorithms are recommended. This study aimed to compare the current, representative diagnostic algorithms for detecting toxigenic C. difficile, using VIDAS C. difficile toxin A&B (toxin ELFA), VIDAS C. difficile GDH (GDH ELFA, bioMérieux, Marcy-l’Etoile, France), and Xpert C. difficile (Cepheid, Sunnyvale, California, USA). In 271 consecutive stool samples, toxigenic culture, toxin ELFA, GDH ELFA, and Xpert C. difficile were performed. We simulated two algorithms: screening by GDH ELFA and confirmation by Xpert C. difficile (GDH + Xpert) and combined algorithm of GDH ELFA, toxin ELFA, and Xpert C. difficile (GDH + Toxin + Xpert). The performance of each assay and algorithm was assessed. The agreement of Xpert C. difficile and two algorithms (GDH + Xpert and GDH+ Toxin + Xpert) with toxigenic culture were strong (Kappa, 0.848, 0.857, and 0.868, respectively). The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of algorithms (GDH + Xpert and GDH + Toxin + Xpert) were 96.7%, 95.8%, 85.0%, 98.1%, and 94.5%, 95.8%, 82.3%, 98.5%, respectively. There were no significant differences between Xpert C. difficile and two algorithms in sensitivity, specificity, PPV and NPV. The performances of both algorithms for detecting toxigenic C. difficile were comparable to that of Xpert C. difficile. Either algorithm would be useful in clinical laboratories and can be optimized in the diagnostic workflow of C. difficile depending on costs, test volume, and clinical needs.

Recurrence of Clostridium difficile Infection in Patients with Inflammatory Bowel Disease: The RECIDIVISM Study

OBJECTIVES

Recurrent Clostridium difficile infection (rCDI) contributes to a significant burden of disease in patients with inflammatory bowel disease (IBD). In this study, we seek to identify risk factors for rCDI in a population of IBD patients at the Mount Sinai Hospital IBD Centre.

METHODS

In this retrospective cohort study, IBD patients with rCDI diagnosed between 2010 and 2013 were identified and compared with IBD patients with single-episode CDI. Multivariate regression was used to identify predictors of rCDI in IBD. Outcome analysis was performed for hospitalizations due to CDI, colectomy, and CDI-attributable mortality.

RESULTS

A total of 503 patients were included, 110 (22%) of whom had IBD (49% CD, 51% ulcerative colitis). Recurrent CDI occurred in 32% of IBD patients compared with 24% of non-IBD patients (P<0.01). IBD patients with rCDI were more likely than those without rCDI to report recent antibiotic therapy (42.9 vs. 30.7%, P<0.01), 5-aminosalicylic acid (5-ASA) use (51.5 vs. 30.7%, P<0.001), steroid use (51.4 vs. 33.3%, P<0.001), and biologic therapy (48.6 vs. 40.0%, P<0.01). Infliximab (34.3 vs. 17.3%, P<0.01) but not adalimumab was associated with more rCDI events. Using a Cox model of predictors of rCDI in IBD, significant predictors included non-ileal Crohn's disease (hazard ratio (HR) 2.85, 95% confidence interval (CI) 1.30-6.30) and the use of 5-ASA (HR 2.15, 95% CI 1.11-4.18).

CONCLUSIONS

Compared with the general population, IBD patients are 33% more likely to experience rCDI. Within the IBD cohort, exposure to certain drug classes (antibiotics, 5-ASA, steroids, certain biologics) and non-ileal Crohn's disease were found to be the predictors of rCDI.

Diagnostic test accuracy of glutamate dehydrogenase for Clostridium difficile: Systematic review and meta-analysis

We performed this systematic review and meta-analysis to assess the diagnostic accuracy of detecting glutamate dehydrogenase (GDH) for Clostridium difficile infection (CDI) based on the hierarchical model. Two investigators electrically searched four databases. Reference tests were stool cell cytotoxicity neutralization assay (CCNA) and stool toxigenic culture (TC). To assess the overall accuracy, we calculated the diagnostic odds ratio (DOR) using a DerSimonian-Laird random-model and area the under hierarchical summary receiver operating characteristics (AUC) using Holling’s proportional hazard models. The summary estimate of the sensitivity and the specificity were obtained using the bivariate model. According to 42 reports consisting of 3055 reference positive comparisons, and 26188 reference negative comparisons, the DOR was 115 (95%CI: 77–172, I² = 12.0%) and the AUC was 0.970 (95%CI: 0.958–0.982). The summary estimate of sensitivity and specificity were 0.911 (95%CI: 0.871–0.940) and 0.912 (95%CI: 0.892–0.928). The positive and negative likelihood ratios were 10.4 (95%CI 8.4–12.7) and 0.098 (95%CI 0.066–0.142), respectively. Detecting GDH for the diagnosis of CDI had both high sensitivity and specificity. Considering its low cost and prevalence, it is appropriate for a screening test for CDI.

The efficacy of intracolonic vancomycin for severe Clostridium difficile colitis: a case series

Background

Clostridium difficile infection (CDI) unresponsive to the standard treatments of metronidazole and oral vancomycin requires aggressive medical management and possible surgical intervention including colectomy. Intracolonic vancomycin therapy has been reported to be particularly promising in the setting of severe CDI in the presence of ileus. This is a descriptive case series exploring the effect of adjunctive intracolonic vancomycin therapy on the morbidity and mortality in patients with moderate to severe CDI.

Methods

A retrospective chart review was conducted on 696 patients with CDI seen at a single institution. Each patient was assigned a severity score and 127 patients with moderate to severe CDI were identified. We describe the clinical presentation, risk factors and hospital course comparing those that received adjunctive intracolonic vancomycin to those that only received standard therapy.

Results

The group that received adjunctive intracolonic vancomycin had higher rates of toxic megacolon, intensive care unit (ICU) admission, and colectomy, and yet maintained a similar mortality rate as the group that received only standard treatment.

Conclusion

The intracolonic vancomycin group experienced more complications but showed a similar mortality rate to the standard therapy group, suggesting that intracolonic vancomycin may impart a protective effect. This study adds further evidence for the need of a randomized controlled study using intracolonic vancomycin as adjunctive therapy in patients presenting with severe CDI.

Predictors of fecal transplant failure

BACKGROUND

Clostridium difficile infection (CDI) is a significant healthcare burden, with increased morbidity and mortality. Traditional treatment regimens using antibiotics for recurrent CDI are significantly less successful compared with 80-90% with fecal microbiota transplantation (FMT). There is a paucity of data on failure rates and mortality after FMT in CDI. This study aims to identify the rates of failure, relapse, and mortality associated with FMT as well as the risk factors for FMT failure.

METHODS

A large retrospective cohort study was carried out including all patients who underwent FMT from December 2012 through May 2014. Patient factors (demographics, comorbidities, immune-suppression, transplant history, antibiotics used, hospitalization, and surgeries), disease factors (number of episodes of CDI, treatments, and severity), and transplant factors (route and number of FMT) were examined. Failure of treatment was defined as no resolution of diarrhea in patients who had been treated with one or more fecal microbiota transplantation within 90 days of FMT.

RESULTS

A total of 201 patients (age 66.6±18.3 years, 62.2% women) were included. The overall failure rate was 12.4%. Patients with failed fecal transplant had increased number of FMTs compared with those who responded (mean 1.92±0.997 vs. 1.29±0.615; P=0.004). No colectomies or death related to CDI were found in our patient population. Significant predictors of failure were female sex (P=0.016), previous hospitalization (P=0.006), and surgery before FMT (P=0.005). The overall mortality rate was 9.0% and failure of FMT was associated with an increased risk of death (odds ratio=5.833, confidence interval 2.01-16.925; P<0.05).

CONCLUSION

FMT is a suitable alterative to antibiotic use for recurrent CDIs, with a high success rate. The results indicate that hospital-acquired CDI may be a predictor of failure of FMT.

Epidemiology, Diagnosis, and Management of Clostridium difficile Infection in Patients with Inflammatory Bowel Disease

Clostridium difficile infection (CDI) is a major source of morbidity and mortality for the U.S. health care system and frequently complicates the course of inflammatory bowel disease (IBD). Patients with IBD are more likely to be colonized with C. difficile and develop active infection than the general population. They are also more likely to have severe CDI and develop subsequent complications such as IBD flare, colectomy, or death. Even after successful initial treatment and recovery, recurrent CDI is common. Management of CDI in IBD is fraught with diagnostic and therapeutic challenges because the clinical presentations of CDI and IBD flare have considerable overlap. Fecal microbiota transplantation can be successful in curing recurrent CDI when other treatments have failed, but may also trigger IBD flare and this warrants caution. New experimental treatments including vaccines, monoclonal antibodies, and nontoxigenic strains of C. difficile offer promise but are not yet available for clinicians. A better understanding of the complex relationship between the gut microbiota, CDI, and IBD is needed.

Fecal Microbiota Therapy for Clostridium difficile Infection: A Health Technology Assessment

BACKGROUND

Fecal microbiota therapy is increasingly being used to treat patients with Clostridium difficile infection. This health technology assessment primarily evaluated the effectiveness and cost-effectiveness of fecal microbiota therapy compared with the usual treatment (antibiotic therapy).

METHODS

We performed a literature search using Ovid MEDLINE, Embase, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, CRD Health Technology Assessment Database, Cochrane Central Register of Controlled Trials, and NHS Economic Evaluation Database. For the economic review, we applied economic filters to these search results. We also searched the websites of agencies for other health technology assessments. We conducted a meta-analysis to analyze effectiveness. The quality of the body of evidence for each outcome was examined according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group criteria. Using a step-wise, structural methodology, we determined the overall quality to be high, moderate, low, or very low. We used a survey to examine physicians' perception of patients' lived experience, and a modified grounded theory method to analyze information from the survey.

RESULTS

For the review of clinical effectiveness, 16 of 1,173 citations met the inclusion criteria. A meta-analysis of two randomized controlled trials found that fecal microbiota therapy significantly improved diarrhea associated with recurrent C. difficile infection versus treatment with vancomycin (relative risk 3.24, 95% confidence interval [CI] 1.85-5.68) (GRADE: moderate). While fecal microbiota therapy is not associated with a significant decrease in mortality compared with antibiotic therapy (relative risk 0.69, 95% CI 0.14-3.39) (GRADE: low), it is associated with a significant increase in adverse events (e.g., short-term diarrhea, relative risk 30.76, 95% CI 4.46-212.44; abdominal cramping, relative risk 14.81, 95% CI 2.07-105.97) (GRADE: low). For the value-for-money component, two of 151 economic evaluations met the inclusion criteria. One reported that fecal microbiota therapy was dominant (more effective and less expensive) compared with vancomycin; the other reported an incremental cost-effectiveness ratio of $17,016 USD per quality-adjusted life-year for fecal microbiota therapy compared with vancomycin. This ratio for the second study indicated that there would be additional cost associated with each recurrent C. difficile infection resolved. In Ontario, if fecal microbiota therapy were adopted to treat recurrent C. difficile infection, considering it from the perspective of the Ministry of Health and Long-Term Care as the payer, an estimated $1.5 million would be saved after the first year of adoption and $2.9 million after 3 years. The contradiction between the second economic evaluation and the savings we estimated may be a result of the lower cost of fecal microbiota therapy and hospitalization in Ontario compared with the cost of therapy used in the US model. Physicians reported that C. difficile infection significantly reduced patients' quality of life. Physicians saw fecal microbiota therapy as improving patients' quality of life because patients could resume daily activities. Physicians reported that their patients were happy with the procedures required to receive fecal microbiota therapy.

CONCLUSIONS

In patients with recurrent C. difficile infection, fecal microbiota therapy improves outcomes that are important to patients and provides good value for money.

Gut microbiota composition and Clostridium difficile infection in hospitalized elderly individuals: a metagenomic study

The gut microbiota composition of elderly hospitalized patients with Clostridium difficile infection (CDI) exposed to previous antibiotic treatment is still poorly investigated. The aim of this study was to compare the microbiota composition by means of 16S rRNA microbial profiling among three groups of hospitalized elderly patients (age ≥ 65) under standard diet including 25 CDI-positive (CDI group), 29 CDI-negative exposed to antibiotic treatment (AB+ group) and 30 CDI-negative subjects not on antibiotic treatment (AB− group). The functional properties of the gut microbiomes of CDI-positive vs CDI-negative subjects were also assessed by shotgun metagenomics. A significantly lower microbial diversity was detected in CDI samples, whose microbiomes clustered separately from CDI-negative specimens. CDI was associated with a significant under-representation of gut commensals with putative protective functionalities, including Bacteroides, Alistipes, Lachnospira and Barnesiella, and over-representation of opportunistic pathogens. These findings were confirmed by functional shotgun metagenomics analyses, including an in-depth profiling of the Peptostreptococcaceae family. In CDI-negative patients, antibiotic treatment was associated with significant depletion of few commensals like Alistipes, but not with a reduction in species richness. A better understanding of the correlations between CDI and the microbiota in high-risk elderly subjects may contribute to identify therapeutic targets for CDI.

Significance of a positive Clostridium difficile toxin test after hematopoietic stem cell transplantation

Patients with hematological malignancies show a high prevalence of asymptomatic colonization with Clostridium difficile (CD colonization). Therefore, it is difficult to distinguish CD colonization with diarrhea induced by a conditioning regimen from true Clostridium difficile infection (CDI) in hematopoietic stem cell transplantation (HSCT) recipients. We retrospectively analyzed 308 consecutive patients who underwent a CD toxin A/B enzyme immunoassay test for diarrhea within 100 d after HSCT from November 2007 to May 2014. Thirty patients (9.7%) had positive CD toxin results, and 11 of these had positive results in subsequent tests after an initial negative result. Allogeneic HSCT, total body irradiation, stem cell source, acute leukemia, and the duration of neutropenia were significantly correlated with positive CD toxin results. In a logistic regression model, allogeneic HSCT was identified as a significant risk factor (odds ratio 18.6, p < 0.01). In an analysis limited to within 30 d after the conditioning regimen, the duration of neutropenia was the sole risk factor (odds ratio 10.4, p < 0.01). There were no distinctive clinical features for CDI, including the onset or duration of diarrhea. In conclusion, although CDI may be overdiagnosed in HSCT recipients, it is difficult to clinically distinguish between CDI and CD colonization.

Clostridium difficile infection: a review of current and emerging therapies

Clostridium difficile (C. difficile) infection (CDI) is the most common cause of ­healthcare-associated infections in US hospitals. The epidemic strain NAP1/BI/ribotype 027 accounts for outbreaks worldwide, with increasing mortality and severity. CDI is acquired from an endogenous source or from spores in the environment, most easily acquired during the hospital stay. The use of antimicrobials disrupts the intestinal microflora enabling C. difficile to proliferate in the colon and produce toxins. Clinical diagnosis in symptomatic patients requires toxin detection from stool specimens and rarely in combination with stool culture to increase sensitivity. However, stool culture is essential for epidemiological studies. Oral metronidazole is the recommended therapy for milder cases of CDI and oral vancomycin or fidaxomicin for more severe cases. Treatment of first recurrence involves the use of the same therapy used in the initial CDI. In the event of a second recurrence oral vancomycin often given in a tapered dose or intermittently, or fidaxomicin may be used. Fecal transplantation is playing an immense role in therapy of recurrent CDI with remarkable results. Fulminant colitis and toxic megacolon warrant surgical intervention. Novel approaches including new antibiotics and immunotherapy against CDI or its toxins appear to be of potential value.

Atypical Presentation of C. Difficile Infection: Report of a Case with Literature Review

Clostridium difficile (C. difficile) is a gram-positive, obligate, anaerobic spore-forming bacillus first reported by Hall and O'Toole in 1935. It occurs mostly after antibiotic use and invariably presents with watery diarrhea. We describe an atypical presentation of C. difficile in a 64-year-old Caucasian female who presented to the our emergency department with abdominal pain, nausea, and vomiting for one day. A complete blood count revealed leukocytosis 30 x 10⁹/L and a subsequent computed tomography (CT) scan of the abdomen and the pelvis, showed fluid filled small bowel loops consistent with enteritis. Her presentation was unusual for lack of diarrhea, the hallmark of C. difficile infection. She was admitted and treated with oral vancomycin. The polymerase chain reaction (PCR) value in the stool for C. difficile was positive. The patient responded very well: her abdominal pain resolved and leukocyte count normalized after a few doses of vancomycin (125 mg po qid). The patient's progress was followed in our clinic for the last three months.

Pathogenic effects of glucosyltransferase from Clostridium difficile toxins

The glucosyltransferase domain ofClostridium difficiletoxins modifies guanine nucleotide-binding proteins of Rho family. It is the major virulent domain of the holotoxins. Various pathogenic effects ofC. difficiletoxins in response to Rho glucosylation have been investigated including cytoskeleton damage, cell death and inflammation. The most recent studies have revealed some significant characteristics of the holotoxins that are independent of glucosylating activity. These findings arouse discussion about the role of glucosyltransferase activity in toxin pathogenesis and open up new insights for toxin mechanism study. In this review, we summarize the pathogenic effects of glucosyltransferase domain of the toxins in the past years.

Fecal Microbiota Transplantation: Current Applications, Effectiveness, and Future Perspectives

Fecal microbiota transplantation (FMT) is the infusion of liquid filtrate feces from a healthy donor into the gut of a recipient to cure a specific disease. A fecal suspension can be administered by nasogastric or nasoduodenal tube, colonoscope, enema, or capsule. The high success rate and safety in the short term reported for recurrent Clostridium difficile infection has elevated FMT as an emerging treatment for a wide range of disorders, including Parkinson's disease, fibromyalgia, chronic fatigue syndrome, myoclonus dystopia, multiple sclerosis, obesity, insulin resistance, metabolic syndrome, and autism. There are many unanswered questions regarding FMT, including donor selection and screening, standardized protocols, long-term safety, and regulatory issues. This article reviews the efficacy and safety of FMT used in treating a variety of diseases, methodology, criteria for donor selection and screening, and various concerns regarding FMT.

Regulation of body fat mass by the gut microbiota: Possible mediation by the brain

New insight suggests gut microbiota as a component in energy balance. However, the underlying mechanisms by which gut microbiota can impact metabolic regulation is unclear. A recent study from our lab shows, for the first time, a link between gut microbiota and energy balance circuitries in the hypothalamus and brainstem. In this article we will review this study further.

Antibacterials Developed to Target a Single Organism: Mechanisms and Frequencies of Reduced Susceptibility to the Novel Anti-Clostridium difficile Compounds Fidaxomicin and LFF571

Clostridium difficile is the most common cause of antibacterial-associated diarrhea. Clear clinical presentation and rapid diagnostics enable targeted therapy for C. difficile infection (CDI) to start quickly. CDI treatment includes metronidazole and vancomycin (VAN). Despite decades of use for CDI, no clinically meaningful resistance to either agent has emerged. Fidaxomicin (FDX), an RNA polymerase inhibitor, is also approved to treat CDI. Mutants with reduced susceptibility to FDX have been selected in vitro by single and multistep methods. Strains with elevated FDX minimum inhibitory concentrations (MICs) were also identified from FDX-treated patients in clinical trials. LFF571 is an exploratory agent that inhibits EF-Tu. In a proof-of-concept study, LFF571 was safe and effective for treating CDI. Spontaneous mutants with reduced susceptibility to LFF571 were selected in vitro in a single step, but not via serial passage. Although there are several agents in development for treatment of CDI, this review summarizes the frequencies and mechanisms of C. difficile mutants displaying reduced susceptibility to FDX or LFF71.

Recent Advances in the Diagnosis and Treatment of Clostridium Difficile Infection

Clostridium difficile infection (CDI) has become the most frequently reported health care-associated infection in the United States [1]. As the incidence of CDI rises, so too does the burden it produces on health care and society. In an attempt to decrease the burden of CDI and provide the best outcomes for patients affected by CDI, there have been many recent advancements in the understanding, diagnosis, and management of CDI. In this article, we review the current recommendations regarding CDI testing and treatment strategies.

Fecal microbiota transplantation for Clostridium difficile infection: back to the future

INTRODUCTION

Clostridium difficile infection (CDI) is a leading cause of diarrhea in the industrialized world. The estimated costs of this infection are impressive: over 3.2 billion dollars annually in the US. The introduction of fecal microbiota transplantation (FMT) to clinical practice can be considered a Copernican Revolution. The rationale of this approach consists of correcting the imbalance of the organisms dwelling in the gut by reintroducing a normal flora.

AREAS COVERED

This review focuses on the indication for FMT in CDI; it examines in-depth the most relevant aspects of the techniques used, and the safety and efficacy of this new 'old' therapy.

EXPERT OPINION

Authoritative guidelines about the management of CDI strongly recommend FMT for multiple recurrent episodes of infection by C. difficile unresponsive to repeated antibiotic treatment. The cure rates are about 90%, with no serious adverse events having been reported. The main concerns are the long-term outcomes, lack of a standardized procedure for the delivery of donor material, and a cultural barrier to the transplantation of fecal microbiota. A promising solution to some of these problems could be the use of a more acceptable administration route of fecal material, namely, oral capsules.

A Diagnostic Algorithm for the Detection of Clostridium difficile-Associated Diarrhea

BACKGROUND

Clostridium difficile is a common cause of hospital-acquired diarrhea, which is usually associated with previous antibiotic use. The clinical manifestations of C. difficile infection (CDI) may range from mild diarrhea to fulminant colitis. Clostridium difficile should be considered in diarrhea cases with a history of antibiotic use within the last 8 weeks (community-associated CDI) or with a hospital stay of at least 3 days, regardless of the duration of antibiotic use (hospital-acquired CDI).

AIMS

This study investigated the frequency of CDI in diarrheic patients and evaluated the efficacy of the triple diagnostic algorithm that is proposed here for C. difficile detection.

STUDY DESIGN

Cross-sectional study.

METHODS

In this study, we compared three methods currently employed for C. difficile detection using 95 patient stool samples: an enzyme immunoassay (EIA) for toxin A/B (C. diff Toxin A+B; Diagnostic Automation Inc.; Calabasas, CA, USA), an EIA for glutamate dehydrogenase (GDH) (C. DIFF CHEK-60TM, TechLab Inc.; Blacksburg, VA, USA), and a polymerase chain reaction (PCR)-based assay (GeneXpert(®) C. difficile; Cepheid, Sunnyvale, CA, USA) that detects C. difficile toxin genes and conventional methods as well. In this study, 50.5% of the patients were male, 50 patients were outpatients, 32 were from inpatient clinics and 13 patients were from the intensive care unit.

RESULTS

Of the 95 stool samples tested for GDH, 28 were positive. Six samples were positive by PCR, while nine samples were positive for toxin A/B. The hypervirulent strain NAP-1 and binary toxin was not detected. The rate of occurrence of toxigenic C. difficile was 5.1% in the samples. Cefaclor, ampicillin-sulbactam, ertapenem, and piperacillin-tazobactam were the most commonly used antibiotics by patients preceding the onset of diarrhea. Among the patients who were hospitalized in an intensive care unit for more than 7 days, 83.3% were positive for CDI by PCR screening. If the PCR test is accepted as the reference: C. difficile Toxin A/B ELISA sensitivity and specificity were 67% and 94%, respectively, and GDH sensitivity and specificity were 100% and 75%, respectively.

CONCLUSION

Tests targeting C. difficile toxins are frequently applied for the purpose of diagnosing CDI in a clinical setting. However, changes in the temperature and reductant composition of the feces may affect toxin stability, potentially yielding false-negative test results. Therefore, employment of a GDH EIA, which has high sensitivity, as a screening test for the detection of toxigenic strains, may prevent false-negative results, and its adoption as part of a multistep diagnostic algorithm may increase accuracy in the diagnosis of CDIs.

Antibiotic Treatment of Hospitalized Patients with Pneumonia Complicated by Clostridium Difficile Infection

Clostridium difficile infection (CDI) is one of the most common gastrointestinal complication after antimicrobial treatment. It is estimated that CDI after pneumonia treatment is connected with a higher mortality than other causes of hospitalization. The aim of the study was to assess the relationship between the kind of antibiotic used for pneumonia treatment and mortality from post-pneumonia CDI. We addressed the issue by examining retrospectively the records of 217 patients who met the diagnostic criteria of CDI. Ninety four of those patients (43.3 %) came down with CDI infection after pneumonia treatment. Fifty of the 94 patients went through severe or severe and complicated CDI. The distribution of antecedent antibiotic treatment of pneumonia in these 50 patients was as follows: ceftriaxone in 14 (28 %) cases, amoxicillin with clavulanate in 9 (18 %), ciprofloxacin in 8 (16.0 %), clarithromycin in 7 (14 %), and cefuroxime and imipenem in 6 (12 %) each. The findings revealed a borderline enhancement in the proportion of deaths due to CDI in the ceftriaxone group compared with the ciprofloxacin, cefuroxime, and imipenem groups. The corollary is that ceftriaxone should be shunned in pneumonia treatment. The study demonstrates an association between the use of a specific antibiotic for pneumonia treatment and post-pneumonia mortality in patients who developed CDI.

Clostridium Difficile Infection Due to Pneumonia Treatment: Mortality Risk Models

One of the most common gastrointestinal infection after the antibiotic treatment of community or nosocomial pneumonia is caused by the anaerobic spore Clostridium difficile (C. difficile). The aim of this study was to retrospectively assess mortality due to C. difficile infection (CDI) in patients treated for pneumonia. We identified 94 cases of post-pneumonia CDI out of the 217 patients with CDI. The mortality issue was addressed by creating a mortality risk models using logistic regression and multivariate fractional polynomial analysis. The patients' demographics, clinical features, and laboratory results were taken into consideration. To estimate the influence of the preceding respiratory infection, a pneumonia severity scale was included in the analysis. The analysis showed two statistically significant and clinically relevant mortality models. The model with the highest prognostic strength entailed age, leukocyte count, serum creatinine and urea concentration, hematocrit, coexisting neoplasia or chronic obstructive pulmonary disease. In conclusion, we report on two prognostic models, based on clinically relevant factors, which can be of help in predicting mortality risk in C. difficile infection, secondary to the antibiotic treatment of pneumonia. These models could be useful in preventive tailoring of individual therapy.

Novel approaches to treating Clostridium difficile-associated colitis

Clostridium difficile is being recognized as a growing threat to many health-care systems. Epidemiology data shows that infection rates are soaring and the disease burden is increasing. Despite the efficacy of standard treatments, it is becoming evident that novel therapeutics will be required to tackle this disease. These new treatments aim to enhance the intestinal microbial barrier, activate the immune system and neutralize the toxins that mediate this disease. Many of these therapies are still in the beginning stages of investigation, however, in the next few years, more clinical data will become available to help implement many of these exciting new therapeutic approaches.