Decreased cure and increased recurrence rates for Clostridium difficile infection caused by the epidemic C. difficile BI strain

Reduced Vancomycin Susceptibility in Clostridioides difficile Is Associated With Lower Rates of Initial Cure and Sustained Clinical Response

BACKGROUND

Epidemiologic studies have shown decreasing vancomycin susceptibility among clinical Clostridioides difficile isolates, but the impact on patient outcomes is unknown. We hypothesized that reduced vancomycin susceptibility would be associated with decreased rates of sustained clinical response (SCR).

METHODS

This multicenter cohort study included adults with C. difficile infection (CDI) treated with oral vancomycin between 2016 and 2021. Clostridioides difficile isolates underwent agar dilution vancomycin susceptibility testing, ribotyping, and Sanger sequencing of the vancomycin resistance vanR gene. Reduced susceptibility was defined as vancomycin minimum inhibitory concentration (MIC) >2 μg/mL. The primary outcome was 30-day SCR; secondary outcomes were 14-day initial cure, 30-day recurrence, and 30-day mortality. Exploratory analysis assessed the association between the VanR Thr115Ala polymorphism, susceptibility, and outcomes.

RESULTS

A high proportion (34% [102/300]) of C. difficile isolates exhibited reduced vancomycin susceptibility (range, 0.5-16 μg/mL; MIC50/90 = 2/4 μg/mL). Ribotype 027 accounted for the highest proportion (77.4% [41/53]) of isolates with reduced vancomycin susceptibility. Overall, 83% (249) of patients achieved 30-day SCR. Reduced vancomycin susceptibility was associated with lower rates of 30-day SCR (76% [78/102]) than vancomycin-susceptible strains (86% [171/198]; P = .031). A significantly lower rate of 14-day initial cure was also observed among individuals infected with strains with reduced vancomycin susceptibility (89% vs 96%; P = .04). Reduced susceptibility remained an independent predictor of 30-day SCR in multivariable modeling (odds ratio, 0.52 [95% confidence interval, .28-.97]; P = .04).

CONCLUSIONS

Reduced vancomycin susceptibility in C. difficile was associated with decreased odds of 30-day SCR and lower 14-day initial cure rates in the studied patient cohort.

The Strain and the Clinical Outcome of Clostridioides difficile Infection: A Meta-analysis

Background

The association between bacterial strains and clinical outcomes in Clostridioides difficile infection (CDI) has yielded conflicting results across studies. We conducted a systematic review and meta-analyses to assess the impact of these strains.

Methods

Five electronic databases were used to identify studies reporting CDI severity, complications, recurrence, or mortality according to strain type from inception to June 2022. Random effect meta-analyses were conducted to assess outcome proportions and risk ratios (RRs).

Results

A total of 93 studies were included: 44 reported recurrences, 50 reported severity or complications, and 55 reported deaths. Pooled proportions of complications were statistically comparable between NAP1/BI/R027 and R001, R078, and R106. Pooled attributable mortality was 4.8% with a gradation in patients infected with R014/20 (1.7%), R001 (3.8%), R078 (5.3%), and R027 (10.2%). Higher 30-day all-cause mortality was observed in patients infected with R001, R002, R027, and R106 (range, 20%-25%).NAP1/BI/R027 was associated with several unfavorable outcomes: recurrence 30 days after the end of treatment (pooled RR, 1.98; 95% CI, 1.02-3.84); admission to intensive care, colectomy, or CDI-associated death (1.88; 1.09-3.25); and 30-day attributable mortality (1.96; 1.23-3.13). The association between harboring the binary toxin gene and 30-day all-cause mortality did not reach significance (RR, 1.6 [0.9-2.9]; 7 studies).

Conclusions

Numerous studies were excluded due to discrepancies in the definition of the outcomes and the lack of reporting of important covariates. NAP1/BI/R027, the most frequently reported and assessed strain, was associated with unfavorable outcomes. However, there were not sufficient data to reach significant conclusions on other strains.

Effect of the COVID-19 Pandemic on Rates and Epidemiology of Clostridioides difficile Infection in One VA Hospital

The COVID-19 pandemic was associated with increases in some healthcare-associated infections. We investigated the impact of the pandemic on the rates and molecular epidemiology of Clostridioides difficile infection (CDI) within one VA hospital. We anticipated that the potential widespread use of antibiotics for pneumonia during the pandemic might increase CDI rates given that antibiotics are a major risk for CDI. Hospital data on patients with CDI and recurrent CDI (rCDI) were reviewed both prior to the COVID-19 pandemic (2015 to 2019) and during the pandemic (2020-2021). Restriction endonuclease analysis (REA) strain typing was performed on CD isolates recovered from stool samples collected from October 2019 to March 2022. CDI case numbers declined by 43.2% in 2020 to 2021 compared to the annual mean over the previous 5 years. The stool test positivity rate was also lower during the COVID-19 pandemic (14.3% vs. 17.2%; p = 0.013). Inpatient hospitalization rates declined, and rates of CDI among inpatients were reduced by 34.2% from 2020 to 2021. The mean monthly cases of rCDI also declined significantly after 2020 [3.38 (95% CI: 2.89-3.87) vs. 1.92 (95% CI: 1.27-2.56); p = <0.01]. Prior to the pandemic, REA group Y was the most prevalent CD strain among the major REA groups (27.3%). During the first wave of the pandemic, from 8 March 2020, to 30 June 2020, there was an increase in the relative incidence of REA group BI (26.7% vs. 9.1%); After adjusting for CDI risk factors, a multivariable logistic regression model revealed that the odds of developing an REA group BI CDI increased during the first pandemic wave (OR 6.41, 95% CI: 1.03-39.91) compared to the pre-pandemic period. In conclusion, the incidence of CDI and rCDI decreased significantly during the COVID-19 pandemic. In contrast, REA BI (Ribotype 027), a virulent, previously epidemic CD strain frequently associated with hospital transmission and outbreaks, reappeared as a prevalent strain during the first wave of the pandemic, but subsequently disappeared, and overall CDI rates declined.

Controversies in the Prevention and Treatment of Clostridioides difficile Infection in Adults: A Narrative Review

Clostridioides difficile remains a problematic pathogen resulting in significant morbidity and mortality, especially for high-risk groups that include immunocompromised patients. Both the Infectious Diseases Society of America and the Society for Healthcare Epidemiology of America (IDSA/SHEA), as well as the American College of Gastroenterology (ACG) and the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) recently provided guideline updates for C. difficile infection (CDI). In this narrative review, the authors reviewed available literature regarding the prevention or treatment of CDI in adults and focused on disagreements between the IDSA/SHEA and ACG guidelines, as well as articles that have been published since the updates. Several options for primary prophylaxis are available, including probiotics and antibiotics (vancomycin, fidaxomicin). The literature supporting fidaxomicin is currently quite limited. While there are more studies evaluating probiotics and vancomycin, the optimal patient populations and regimens for their use have yet to be defined. While the IDSA/SHEA guidelines discourage metronidazole use for mild CDI episodes, evidence exists that it may remain a reasonable option for these patients. Fidaxomicin has an advantage over vancomycin in reducing recurrences, but its use is limited by cost. Despite this, recent studies suggest fidaxomicin's cost-effectiveness as a first-line therapy, though this is highly dependent on institutional contracts and payment structures. Secondary prophylaxis should focus on non-antimicrobial options to lessen the impact on the microbiome. The oral option of fecal microbiota transplantation (FMT), SER109, and the now FDA-approved RBX2660 represent exciting new options to correct dysbiosis. Bezlotoxumab is another attractive option to prevent recurrences. Further head-to-head studies of newer agents will be needed to guide selection of the optimal therapies for CDI primary and secondary prophylaxis.

The Efficacy of Bezlotoxumab in the Prevention of Recurrent Clostridium difficile: A Systematic Review

Clostridium difficile infection (CDI) is the most common nosocomial infection in hospitals. Despite the fact that CDI has treatment options, recurrence is common after the treatment, recurrence will occur in approximately 20%-35% of people initially affected, with 40%-60% of these having a second recurrence. Patients are more likely to have several recurrences after the second, which can lead to antibiotic overuse, and as a result, CDI-related health care expenses, hospitalizations, and mortality are on the rise. The first treatment to receive Food and Drug Administration (FDA) approval for the prevention of C. difficile recurrence is bezlotoxumab, a novel human monoclonal antibody against C. difficile toxin B. In the present systematic review, we assessed various studies from PubMed, PubMed Central (PMC), Google Scholar, and Science direct that evaluated the efficacy of bezlotoxumab in the prevention of recurrent C. difficile (rCDI), and we also briefly discussed the pathophysiology of C. difficile and the risk factors for recurrence of C. difficile. The major MODIFY trial has proven the efficacy, pooled analysis of MODIFY 1 AND 2 trials demonstrated the following results as compared to placebo (bezlotoxumab: 129/781 [16.5] placebo:206/773 [26.6] -10.0% [95% CI -14.0 to -6.0], p<0.0001) with number needed to treat (NNT) of 10. All other observational studies also showed a positive response with bezlotoxumab in the prevention of C. difficile. In conclusion, bezlotoxumab is a great option adjunctive with standard of care CDI antibiotics for the prevention of rCDI in high-risk adults.

Which is the Preferred Regimen for Non-Severe Clostridioides difficile Infection in Korea, Vancomycin or Metronidazole?

The emergence of hypervirulent Clostridioides difficile strains has decreased the efficacy of metronidazole in the treatment of C. difficile infection (CDI). Therefore, revised guidelines no longer recommend the use of metronidazole as a first-line regimen for CDI and restrict its use for non-severe CDI, only when vancomycin and fidaxomicin are unavailable. In Korea, an epidemic caused by a hypervirulent C. difficile strain or the emergence of metronidazole resistant C. difficile strains have not been reported. This review article aims to compare the treatment outcomes and adverse effects of vancomycin and metronidazole and discuss the validity of the guidelines of various agencies, which restrict the use of metronidazole, for Korean patients. There are no substantial adverse effects of metronidazole, and its clinical outcomes against non-severe CDI are similar to those of vancomycin. Based on these findings, we recommend that the use of metronidazole for the treatment of non-severe CDI is still an appropriate option in Korea.

Characterization of the Effects of Candida Gastrointestinal Colonization on Clostridioides difficile Infection in a Murine Model

The role of fungal colonizers of the gastrointestinal tract during disease states is not well understood. Antibiotic treatment renders patients highly susceptible to infection by the bacterial pathogen C. difficile while also leading to blooms in fungal commensals, setting the stage for trans-kingdom interactions. Here, we describe a murine model of Candida gastrointestinal colonization coupled to a C. difficile infection (CDI) model, the measurement of CFU of both organisms, and collection of cecum and colon contents for the purpose of quantifying C. difficile toxin production. Additionally, we describe how to induce and purify C. difficile spores.

Can prediction scores be used to identify patients at risk of Clostridioides difficile infection?

PURPOSE OF REVIEW

To describe the current state of literature on modeling risk of incident and recurrent Clostridioides difficile infection (iCDI and rCDI), to underscore limitations, and to propose a path forward for future research.

RECENT FINDINGS

There are many published risk factors and models for both iCDI and rCDI. The approaches include scores with a limited list of variables designed to be used at the bedside, but more recently have also included automated tools that take advantage of the entire electronic health record. Recent attempts to externally validate scores have met with mixed success.

SUMMARY

For iCDI, the performance largely hinges on the incidence, which even for hospitalized patients can be low (often <1%). Most scores fail to achieve high accuracy and/or are not externally validated. A challenge in predicting rCDI is the significant overlap with risk factors for iCDI, reducing the discriminatory ability of models. Automated electronic health record-based tools show promise but portability to other centers is challenging. Future studies should include external validation and consider biomarkers to augment performance.

The Integrity of Heme Is Essential for Reproducible Detection of Metronidazole-Resistant Clostridioides difficile by Agar Dilution Susceptibility Tests

Metronidazole resistance in clinical Clostridioides difficile is often described as unstable, since resistant strains reportedly appear susceptible following freezer storage or brief passage. This has presented a conundrum for adopting susceptibility testing to accurately evaluate the connection between metronidazole resistance and decreased clinical efficacy of metronidazole in patients with C. difficile infections (CDIs). We discovered that supplementation of microbiological media with the metalloporphyrin heme is crucial for detection of metronidazole-resistant C. difficile using the agar dilution susceptibility testing method. Known metronidazole-resistant strains appeared susceptible to metronidazole in media lacking heme. Similarly, these resistant strains exhibited increased susceptibility to metronidazole when tested on heme-containing agars that were exposed to room light for more than 1 day, likely due to heme photodecomposition. In parallel experiments, resistance was reproducibly detected when heme-containing agars were either prepared and used on the same day or protected from light and then used on subsequent days. Notably, heme did not influence the susceptibilities of drug-susceptible strains that were of the same ribotype as the resistant strains. These findings firmly show that the consistent detection of metronidazole-resistant C. difficile is dependent upon heme and its protection from light. Studies are warranted to determine the extent to which this heme-associated metronidazole-resistant phenotype affects the clinical efficacy of metronidazole in CDI and the underlying genetic and biochemical mechanisms.

Oral Vancomycin as Secondary Prophylaxis for Clostridioides difficile Infection

OBJECTIVES

Secondary oral vancomycin prophylaxis (OVP) has been used in adults with a history of Clostridioides difficile infection (CDI) while receiving systemic antibiotics to prevent CDI recurrence. However, this practice has not been studied in pediatric patients. The objective of this study was to assess the utility of secondary OVP in pediatric patients with previous CDI who received subsequent antibiotic exposure.

METHODS

A multicampus, retrospective cohort evaluation was conducted among patients aged ≤18 years with any history of clinical CDI and receiving systemic antibiotics in a subsequent encounter from 2013-2019. Patients who received concomitant OVP with antibiotics were compared with unexposed patients. The primary outcome was CDI recurrence within 8 weeks after antibiotic exposure. Infection with vancomycin-resistant enterococci and risk factors for CDI recurrence were assessed.

RESULTS

A total of 148 patients were screened, of which 30 and 44 patients received OVP and no OVP, respectively. Patients who received OVP had greater antibiotic use and hospital lengths of stay. The incidence of CDI recurrence within 8 weeks of antibiotic exposure was significantly lower in patients who received OVP (3% vs 25%; P = .02) despite this group having notably more risk factors for recurrence. There were no vancomycin-resistant enterococci infections in any patients within either group. After adjustment in a multivariable analysis, secondary OVP was associated with less risk of recurrence (odds ratio, 0.10; 95% confidence interval, 0.01-0.86; P = .04).

CONCLUSIONS

Secondary OVP while receiving systemic antibiotics reduces the risk of recurrent CDI in pediatric patients with a history of CDI.

Nonalcoholic Fatty Liver Disease-A Novel Risk Factor for Recurrent Clostridioides difficile Infection

Recurrent Clostridioides difficile infections (rCDI) have a substantial impact on healthcare systems, with limited and often expensive therapeutic options. Nonalcoholic fatty liver disease (NAFLD) affects about 25% of the adult population and is associated with metabolic syndrome, changes in gut microbiome and bile acids biosynthesis, all possibly related with rCDI. The aim of this study was to determine whether NAFLD is a risk factor associated with rCDI. A retrospective cohort study included patients ≥ 60 years hospitalized with CDI. The cohort was divided into two groups: those who were and were not readmitted with CDI within 3 months of discharge. Of the 329 patients included, 107 patients (32.5%) experienced rCDI. Patients with rCDI were older, had higher Charlson Age-Comorbidity Index (CACI) and were more frequently hospitalized within 3 months. Except for chronic kidney disease and NAFLD, which were more frequent in the rCDI group, there were no differences in other comorbidities, antibiotic classes used and duration of antimicrobial therapy. Multivariable Cox regression analysis showed that age >75 years, NAFLD, CACI >6, chronic kidney disease, statins and immobility were associated with rCDI. In conclusion, our study identified NAFLD as a possible new host-related risk factor associated with rCDI.

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.

Risk Factors Associated with Recurrent Clostridioides difficile Infection

Clostridioides difficile (CD) is responsible for nosocomial diarrhea syndrome with possible severe progression. Recurrence of the disease induces higher health system costs, as well as exposes patients to additional health risks. Patients with recurrence of this disease are difficult to identify, so the purpose of this study is to quantify various demographic, clinical, and treatment factors that could prevent further progression to recurrence of the disease. In the period 2018–2019, about 195 patients were diagnosed with more than one episode of CDI in the three months following the first episode. The recurrence rate for CDI was 53.84% (60.95% for one episode and 39.05% for multiple episodes). Most commonly afflicted were 60–69-year-old patients, or those with higher Charlson Comorbidity Index (CCI). Multiple analyses associated cardiovascular (odds ratios (OR) = 3.02, 95% confidence intervals (CI) = 1.23–7.39, p = 0.015), digestive (OR = 3.58, 95% CI = 1.01–12.63, p = 0.047), dementia (OR = 3.26, 95% CI = 1.26–8.41, p = 0.014), immunosuppressive (OR = 3.88, 95% CI = 1.34–11.21, p = 0.012) comorbidities with recurrences. Risk factor identification in the first episode of CDI could lead to the implementation of treatment strategies to improve the patients’ quality of life affected by this disease.

Risk Factors Associated with Recurrent Clostridioides difficile Infection

Clostridioides difficile (CD) is responsible for nosocomial diarrhea syndrome with possible severe progression. Recurrence of the disease induces higher health system costs, as well as exposes patients to additional health risks. Patients with recurrence of this disease are difficult to identify, so the purpose of this study is to quantify various demographic, clinical, and treatment factors that could prevent further progression to recurrence of the disease. In the period 2018-2019, about 195 patients were diagnosed with more than one episode of CDI in the three months following the first episode. The recurrence rate for CDI was 53.84% (60.95% for one episode and 39.05% for multiple episodes). Most commonly afflicted were 60-69-year-old patients, or those with higher Charlson Comorbidity Index (CCI). Multiple analyses associated cardiovascular (odds ratios (OR) = 3.02, 95% confidence intervals (CI) = 1.23-7.39, p = 0.015), digestive (OR = 3.58, 95% CI = 1.01-12.63, p = 0.047), dementia (OR = 3.26, 95% CI = 1.26-8.41, p = 0.014), immunosuppressive (OR = 3.88, 95% CI = 1.34-11.21, p = 0.012) comorbidities with recurrences. Risk factor identification in the first episode of CDI could lead to the implementation of treatment strategies to improve the patients' quality of life affected by this disease.

Human C. difficile toxin-specific memory B cell repertoires encode poorly neutralizing antibodies

Clostridioides difficile is a leading cause of nosocomial infection responsible for significant morbidity and mortality with limited options for therapy. Secreted C. difficile toxin B (TcdB) is a major contributor to disease pathology, and select TcdB-specific Abs may protect against disease recurrence. However, the high frequency of recurrence suggests that the memory B cell response, essential for new Ab production following C. difficile reexposure, is insufficient. We therefore isolated TcdB-specific memory B cells from individuals with a history of C. difficile infection and performed single-cell deep sequencing of their Ab genes. Herein, we report that TcdB-specific memory B cell–encoded antibodies showed somatic hypermutation but displayed limited isotype class switch. Memory B cell–encoded mAb generated from the gene sequences revealed low to moderate affinity for TcdB and a limited ability to neutralize TcdB. These findings indicate that memory B cells are an important factor in C. difficile disease recurrence.

The C. difficile toxin-specific human memory B cell repertoire encodes low-affinity, non-neutralizing antibodies.

Efficacy of bezlotoxumab in trial participants infected with Clostridioides difficile strain BI associated with poor outcomes

BACKGROUND

Bezlotoxumab reduced rates of recurrent Clostridioides difficile infection (rCDI) versus placebo in MODIFY I/II trial participants receiving antibacterial drug treatment for CDI. A secondary objective of MODIFY I/II was to assess bezlotoxumab's efficacy against C. difficile strains associated with increased rates of morbidity and mortality.

METHODS

In this post-hoc analysis of pooled MODIFY I/II data, efficacy endpoints were assessed in participants infected with restriction endonuclease analysis (REA) BI and non-BI strains of C. difficile at study entry. Treatment outcomes were compared between participants receiving bezlotoxumab (alone or with actoxumab: B, B+A) and those receiving no bezlotoxumab (placebo or actoxumab: P, A).

RESULTS

From 2559 randomized participants, C. difficile was isolated from 1588 (67.2%) baseline stool samples. Participants with BI strains (n=328) were older and had more risk factors for rCDI than non-BI strain participants (n=1260). There were no differences in initial clinical cure rate between BI and non-BI strains in either group. The rCDI rates for BI strains treated with bezlotoxumab was lower than for the no bezlotoxumab group (B, B+A vs P, A: 23.6% vs 43.9%) and was also lower for the non-BI strains (B, B+A vs P, A: 21.4% vs 36.1%). Rates of 30-day CDI-associated re-hospitalization were greater with BI versus non-BI strains in both groups.

CONCLUSIONS

Infection with BI strains of C. difficile predicted poor outcomes in the MODIFY I/II trials. Bezlotoxumab (B, B+A) treatment was effective both in BI and non-BI subpopulations.

Lipid Species in the GI Tract are Increased by the Commensal Fungus Candida albicans and Decrease the Virulence of Clostridioides difficile

Prior antibiotic treatment is a risk factor for Clostridioides difficile infection (CDI); the commensal gut microbiota plays a key role in determining host susceptibility to the disease. Previous studies demonstrate that the pre-colonization of mice with a commensal fungus, Candida albicans, protects against a lethal challenge with C. difficile spores. The results reported here demonstrate that the cecum contents of antibiotic-treated mice with C. albicans colonization contained different levels of several lipid species, including non-esterified, unsaturated long-chain fatty acids compared to non-C. albicans-colonized mice. Mice fed olive oil for one week and challenged with C. difficile spores showed enhanced survival compared to PBS-fed mice. The amount of olive oil administered was not sufficient to cause weight gain or to result in significant changes to the bacterial microbiota, in contrast to the effects of a high-fat diet. Furthermore, the direct exposure of C. difficile bacteria in laboratory culture to the unsaturated fatty acid oleic acid, the major fatty acid found in olive oil, reduced the transcription of genes encoding the toxins and reduced the survival of bacteria in the post-exponential phase. Therefore, the effects of C. albicans on the metabolite milieu contributed to the attenuation of C. difficile virulence.

Economic evaluation of Faecal microbiota transplantation compared to antibiotics for the treatment of recurrent Clostridioides difficile infection

BACKGROUND

Clostridioides difficile infection (CDI) is a hospital acquired disease associated with significant morbidity, hospitalisation and mortality. Almost 30% of treated patients experience at least one recurrence after treatment of their first episode. Treatment of recurrent CDI (rCDI) utilises vancomycin or fidaxomicin, however, a newer treatment option is faecal microbial transplantation (FMT) administered by nasogastric tube (NGT) or colonoscopy. It is associated with higher cure and lower recurrence rates than fidaxomicin or vancomycin. The aim of this analysis is to evaluate the cost effectiveness of FMT for rCDI using the latest and best evidence.

METHOD

A cost utility analysis was conducted using a decision model representing the cost per additional Quality Adjusted Life Year (QALY) from a National Health Service (NHS) perspective. A Markov model was constructed to compare FMT NGT and colonoscopy to antibiotic treatment (fidaxomicin or vancomycin). The model was informed by a literature review of clinical evidence, specifically focussing on hospitalised patients with rCDI over 65 years. Both deterministic and probabilistic sensitivity analyses were performed to assess uncertainties around the model inputs and assumptions.

FINDINGS

The base case analysis showed that FMT is a less costly and more effective treatment than either fidaxomicin or vancomycin. FMT colonoscopy was slightly more effective than FMT NGT leading to an additional 0.012 QALYs but more expensive and the incremental cost effectiveness ratio (ICER) was £242,514/QALY. The Probabilistic sensitivity analysis based on 10,000 simulations suggested the probability of FMT NGT being cost effective was almost 78% at £20,000/QALY Willingness-To-Pay (WTP) threshold.

INTERPRETATION

FMT is both more effective and less costly option than antimicrobial therapy. FMT NGT was the preferred route of administration and is likely to be considered the most cost-effective strategy by decision makers given current acceptable thresholds.

Auranofin, at clinically achievable dose, protects mice and prevents recurrence from Clostridioides difficile infection

Clostridioides difficile is the leading cause of nosocomial infections and a worldwide urgent public health threat. Without doubt, there is an urgent need for new effective anticlostridial agents due to the increasing incidence and severity of C. difficile infection (CDI). The aim of the present study is to investigate the in vivo efficacy of auranofin (rheumatoid arthritis FDA-approved drug) in a CDI mouse model and establish an adequate dosage for treatment. The effects of increased C. difficile inoculum, and pre-exposure to simulated gastric intestinal fluid (SGF) and simulated intestinal fluid (SIF), on the antibacterial activity of auranofin were investigated. Auranofin's in vitro antibacterial activity was stable in the presence of high bacterial inoculum size compared to vancomycin and fidaxomicin. Moreover, it maintained its anti-C. difficile activity after being exposed to SGF and SIF. Upon testing in a CDI mouse model, auranofin at low clinically achievable doses (0.125 mg/kg and 0.25 mg/kg) significantly protected mice against CDI with 100% and 80% survival, respectively. Most importantly, auranofin (0.125 mg/kg and 0.25 mg/kg) significantly prevented CDI recurrence when compared with vancomycin. Collectively, these results indicate that auranofin could potentially provide an effective, safe and quick supplement to the current approaches for treating CDI.

Genetic Association Reveals Protection against Recurrence of Clostridium difficile Infection with Bezlotoxumab Treatment

Clostridium difficile infection is associated with significant clinical morbidity and mortality; antibacterial treatments are effective, but recurrence of C. difficile infection is common. In this genome-wide association study, we explored whether host genetic variability affected treatment responses to bezlotoxumab, a human monoclonal antibody that binds C. difficile toxin B and is indicated for the prevention of recurrent C. difficile infection. Using data from the MODIFY I/II phase 3 clinical trials, we identified three genetic variants associated with reduced rates of C. difficile infection recurrence in bezlotoxumab-treated participants. The effects were most pronounced in participants at high risk of C. difficile infection recurrence. All three variants are located in the extended major histocompatibility complex on chromosome 6, suggesting the involvement of a host-driven immunological mechanism in the prevention of C. difficile infection recurrence.

Bezlotoxumab is a human monoclonal antibody against Clostridium difficile toxin B, indicated to prevent recurrence of C. difficile infection (rCDI) in high-risk adults receiving antibacterial treatment for CDI. An exploratory genome-wide association study investigated whether human genetic variation influences bezlotoxumab response. DNA from 704 participants who achieved initial clinical cure in the phase 3 MODIFY I/II trials was genotyped. Single nucleotide polymorphisms (SNPs) and human leukocyte antigen (HLA) imputation were performed using IMPUTE2 and HIBAG, respectively. A joint test of genotype and genotype-by-treatment interaction in a logistic regression model was used to screen genetic variants associated with response to bezlotoxumab. The SNP rs2516513 and the HLA alleles HLA-DRB1*07:01 and HLA-DQA1*02:01, located in the extended major histocompatibility complex on chromosome 6, were associated with the reduction of rCDI in bezlotoxumab-treated participants. Carriage of a minor allele (homozygous or heterozygous) at any of the identified loci was related to a larger difference in the proportion of participants experiencing rCDI versus placebo; the effect was most prominent in the subgroup at high baseline risk for rCDI. Genotypes associated with an improved bezlotoxumab response showed no association with rCDI in the placebo cohort. These data suggest that a host-driven, immunological mechanism may impact bezlotoxumab response. Trial registration numbers are as follows: NCT01241552 (MODIFY I) and NCT01513239 (MODIFY II).

IMPORTANCEClostridium difficile infection is associated with significant clinical morbidity and mortality; antibacterial treatments are effective, but recurrence of C. difficile infection is common. In this genome-wide association study, we explored whether host genetic variability affected treatment responses to bezlotoxumab, a human monoclonal antibody that binds C. difficile toxin B and is indicated for the prevention of recurrent C. difficile infection. Using data from the MODIFY I/II phase 3 clinical trials, we identified three genetic variants associated with reduced rates of C. difficile infection recurrence in bezlotoxumab-treated participants. The effects were most pronounced in participants at high risk of C. difficile infection recurrence. All three variants are located in the extended major histocompatibility complex on chromosome 6, suggesting the involvement of a host-driven immunological mechanism in the prevention of C. difficile infection recurrence.

Antimicrobial susceptibility of Clostridioides difficile isolated from diarrhoeal stool specimens of Canadian patients: summary of results from the Canadian Clostridioides difficile (CAN-DIFF) surveillance study from 2013 to 2017

Objectives

To summarize data generated by the Canadian Clostridioides difficile (CAN-DIFF) surveillance study from 2013 to 2017.

Methods

Isolates of C. difficile (n = 2158) were cultured from toxin-positive diarrhoeal stool specimens submitted by eight hospital laboratories to a coordinating laboratory. Antimicrobial susceptibility testing was performed according to the CLSI agar dilution method (M11, 2018). Isolate ribotypes were determined using an international, standardized, high-resolution capillary gel-based electrophoresis protocol.

Results

Of the 2158 isolates of C. difficile, 2133 (98.8%) had vancomycin MICs ≤2 mg/L [i.e. were vancomycin susceptible (EUCAST breakpoint tables, v 9.0, 2019) or WT (CLSI M100, 29th edition, 2019)]. Fidaxomicin MICs were lower than those of all other agents tested (MIC90, 0.5 mg/L); however, one isolate with a fidaxomicin MIC of &gt;8 mg/L was identified. Metronidazole MICs ranged from 0.12 to 4 mg/L; all isolates were metronidazole susceptible by the CLSI breakpoint (≤8 mg/L) compared with 96.8% susceptible by the EUCAST breakpoint (≤2 mg/L). In total, 182 different ribotypes were identified from 2013 to 2017. The most common ribotypes identified were 027 (19.3% of isolates) and 106 (8.2%). Ribotype 027 isolates were frequently moxifloxacin resistant (87.3% of isolates) and MDR (48.6%), associated with vancomycin (10/25, 40.0%) and metronidazole (58/69, 84.1%) resistance and from patients aged ≥80 years. The prevalence of ribotype 027 decreased significantly (P &lt; 0.0001) from 2013 (27.5%) to 2017 (9.0%) and was replaced by increases in ribotype 106 (P = 0.0003) and multiple less common ribotypes.

Conclusions

Periodic surveillance is required to monitor clinical isolates of C. difficile for changes to in vitro susceptibility testing profiles and ribotype evolution.

Surotomycin (A Novel Cyclic Lipopeptide) vs. Vancomycin for the Treatment of Clostridioides difficile Infection: A Systematic Review and Meta-analysis

Background:

Current guidelines recommend the use of vancomycin for the initial treatment of moderate to severe Clostridioides difficile Infection (CDI). Surotomycin, a novel antibiotic, has been utilized for the management of CDI with variable results.

Methods:

A systematic literature search was performed using the following electronic databases [Medline, Embase, google scholar and Cochrane] for eligible studies. Randomized controlled trials comparing Surotomycin with Vancomycin for the CDI treatment were included. Demographic variables and outcomes (CDI resolution, CDI recurrence, B1/NAP1/027-specific strain treatment, B1/NAP1/027-strain recurrence, death not related to treatment) were analyzed. The primary outcome was clinical cure rate defined as the resolution of CDI at the end of the 10-day drug course.

Results:

Three RCTs met the inclusion criteria with a total of 1280 patients with CDI who received either surotomycin 250 mg twice daily (642 patients) or vancomycin 125 mg four times daily (638 patients). Clinical cure rates after 10 days of treatment with either surotomycin or vancomycin were not significantly different (pooled OR: 0.89, 95% CI 0.66-1.18, p=0.41). Sustained clinical response at clinical follow-up and the overall recurrence of CDI were also not significantly different between the two groups – pooled OR 1.15 (95% CI 0.89-1.50, p=0.29) and pooled OR 0.74 (95%CI 0.52- 1.04, p=0.08), respectively. With regards to the NAP1/BI/027 strain, patients in the surotomycin group had significantly lower rates of recurrence compared to vancomycin (pooled OR 0.35, 95% CI 0.19-0.63, p<0.01).

Conclusion:

Surotomycin is non-inferior to vancomycin and offers a promising alternative for the treatment and prevention of C. diff infection.

Virulence Factors of Clostridioides (Clostridium) difficile Linked to Recurrent Infections

From 20 to 30% of Clostridioides (Clostridium) difficile infection (CDI), patients might develop recurrence of the infection (RCDI) and, after the first recurrence, the risk of further episodes increases up to 60%. Several bacterial virulence factors have been associated with RCDI, including the elevated production of toxins A and B, the presence of a binary toxin CDT, and mutations in the negative regulator of toxin expression, tcdC. Additional factors have shown to regulate toxin production and virulence in C. difficile in RCDI, including the accessory-gene regulator agr, which acts as a positive switch for toxin transcription. Furthermore, adhesion and motility-associated factors, such as Cwp84, SlpA, and flagella, have shown to increase the adhesion efficiency to host epithelia, cell internalization, and the formation of biofilm. Finally, biofilm confers to C. difficile protection from antibiotics and acts as a reservoir for spores that allow the persistence of the infection in the host. In this review, we describe the key virulence factors of C. difficile that have been associated with recurrent infections.

The early stage peptidoglycan biosynthesis Mur enzymes are antibacterial and antisporulation drug targets for recurrent Clostridioides difficile infection

Sporulation during Clostridioides difficile infection (CDI) contributes to recurrent disease. Cell division and sporulation both require peptidoglycan biosynthesis. We show C. difficile growth and sporulation is attenuated by antisenses to murA and murC or the MurA inhibitor fosfomycin. Thus, targeting the early steps of peptidoglycan biosynthesis might reduce the onset of recurrent CDI.

Recurrent community-acquired Clostridium(Clostridioides)difficile infection in Serbianchildren

Information on recurrent Clostridium difficile infections (rCDI) in children is rare and limited, especially community acquired (CA-CDI).This study was designed to identify risk factors for rCA-CDI in Serbian pediatric population. The study group included 71 children (aged from 1 to 14 years) with a first episode of CDI. Data were collected from 56 (78.87%) children with only one episode of CA-CDI and from 15 (21.13%) children with rCA-CDI were mutually compared. The following parameters were found to be statistically significantly more frequent in the children with rCA-CDI group (p < 0.05); leukemia as underlying disease, treatment with immunosuppressive and-or cytostatic drugs, and treatment with antibiotics. Similarly, previously visits to outpatient facilities, daycare hospitals and hospitals were also associated with rCDI. Analysis of clinical symptoms and laboratory parameters, revealed a statistically significant association of the severity of the first episode of CDI (determined by an increase in body temperature, higher maximum WBC and higher CRP) with development of a rCDI. Ribotype (RT) 027 was more common in children with rCA-CDI (66.7%, p = 0.006). During the seven-year research period, we found a rate of rCA-CDI rate in children of 21.13%. Our study identified several parameters statistically significantly more frequently in children with rCA-CDI. The obtained results will serve as a basis for future larger studies, but new prospective, studies are necessary to build a prediction model of rCDI in children that can be used to guide the treatment to prevent rCDI.

Risk Factors for BI/NAP1/027 Clostridioides difficile Infections and Clinical Outcomes Compared With Non-NAP1 Strains

We aim to describe the characteristics, risk factors, and clinical outcomes associated with NAP1 strain Clostridioides difficile infection (CDI) in this single-center, retrospective, case–control (1:1) study. We found that the NAP1 strain accounted for 19.7% of CDI, and risk factors for acquisition included residence in skilled nursing facilities, previous CDI, and proton pump inhibitor use.

Updates in Treatment of Recurrent Clostridium difficile Infection

Recurrent Clostridium difficile infection (CDI) is a perpetual problem that leads to increased economic burden, higher healthcare cost, and significant morbidity and mortality. Its treatment remains a challenge. While various treatment approaches have been attempted with different levels of success, robust data establishing the superiority of one approach over the others is lacking. In this article, we review the current evidence pertaining to conventional pharmacological treatment as well as fecal microbiota transplantation (FMT) as a novel, rapidly emerging treatment modality for recurrent CDI.

Recurrent Clostridium difficile Infection: Risk Factors, Treatment, and Prevention

The most common cause of antibiotic-associated diarrhea is Clostridium difficile infection (CDI). Recurrent C. difficile infection (rCDI) often occurs after successful treatment of CDI. Due to the increased incidence and the difficulty in treating rCDI, it is becoming an important clinical issue. Identifying risk factors is helpful for early detection, treatment, and prevention of rCDI. Advanced age, use of antibiotics, gastric acid suppression, and infection with a hypervirulent strain are currently regarded as the major risk factors for rCDI. Several treatment modalities, including vancomycin, fidaxomicin, and fecal microbiota transplant (FMT), are suggested for rCDI treatment. However, there is currently no definitive treatment method with sufficient evidence for rCDI. Recent studies have focused on FMT and have shown positive results for rCDI. Prevention of rCDI by measures such as hand washing and isolation of patients is very important. However, these preventive measures are often overlooked in clinical practice. Here, we review the risk factors, treatment, and prevention of rCDI.

Enterotoxic Clostridia: Clostridioides difficile Infections

Clostridioides difficile is a Gram-positive, anaerobic, spore forming pathogen of both humans and animals and is the most common identifiable infectious agent of nosocomial antibiotic-associated diarrhea. Infection can occur following the ingestion and germination of spores, often concurrently with a disruption to the gastrointestinal microbiota, with the resulting disease presenting as a spectrum, ranging from mild and self-limiting diarrhea to severe diarrhea that may progress to life-threating syndromes that include toxic megacolon and pseudomembranous colitis. Disease is induced through the activity of the C. difficile toxins TcdA and TcdB, both of which disrupt the Rho family of GTPases in host cells, causing cell rounding and death and leading to fluid loss and diarrhea. These toxins, despite their functional and structural similarity, do not contribute to disease equally. C. difficile infection (CDI) is made more complex by a high level of strain diversity and the emergence of epidemic strains, including ribotype 027-strains which induce more severe disease in patients. With the changing epidemiology of CDI, our understanding of C. difficile disease, diagnosis, and pathogenesis continues to evolve. This article provides an overview of the current diagnostic tests available for CDI, strain typing, the major toxins C. difficile produces and their mode of action, the host immune response to each toxin and during infection, animal models of disease, and the current treatment and prevention strategies for CDI.

Multilocus Variable-Number Tandem-Repeat Analysis of Clostridioides difficile Clusters in Ribotype 027 Isolates and Lack of Association with Clinical Outcomes

The epidemiology of Clostridioides difficile infection (CDI) has drastically changed since the emergence of the epidemic strain BI/NAP1/027, also known as ribotype 027 (R027). However, the relationship between the infecting C. difficile strain and clinical outcomes is still debated. We hypothesized that certain subpopulations of R027 isolates could be associated with unfavorable outcomes. We applied high-resolution multilocus variable-number tandem-repeat analysis (MLVA) to characterize C. difficile R027 isolates collected from confirmed CDI patients recruited across 10 Canadian hospitals from 2005 to 2008. PCR ribotyping was performed first to select R027 isolates that were then analyzed by MLVA (n = 450). Complicated CDI (cCDI) was defined by the occurrence of any of admission to an intensive care unit, colonic perforation, toxic megacolon, colectomy, and if CDI was the cause or contributed to death within 30 days after enrollment. Three major MLVA clusters were identified, MC-1, MC-3, and MC-10. MC-1 and MC-3 were exclusive to Quebec centers, while MC-10 was found only in Ontario. Fewer cases infected with MC-1 developed cCDI (4%) than those infected with MC-3 and MC-10 (15% and 16%, respectively), but a statistically significant difference was not reached. Our data did not identify a clear association between subpopulations of R027 and different clinical outcomes; however, the data confirmed the utility of MLVA's higher discrimination potential to better characterize CDI populations in an epidemiological analysis. For a patient with CDI, the progression toward an unfavorable outcome is a complex process that probably includes several interrelated strain and host characteristics.

To Lump or To Split: Does Strain Lineage for Clostridioides difficile Matter?

Since 2001, numerous descriptive ecological studies of Clostridioides difficile infections (CDI) have identified a single lineage (BI/NAP1/027) associated with the epidemics of CDI, increased severity of CDI, and increased likelihood of incident CDI to become recurrent. Establishing causality between the clinical severity and outcomes for CDI and the lineages of the infecting strains, however, has proved elusive, with many conflicting results in previous observational studies. In this issue of the Journal of Clinical Microbiology, J. R. Garneau, C. N. Abou Chakra, L.-C. Fortier, A.-C. Labbé, et al. (J Clin Microbiol 57:e01724-18, 2019, https://doi.org/10.1128/JCM.01724-18) performed multilocus variable-number tandem-repeat analysis (MLVA) on 450 isolates from epidemic strain CDI arising in 10 Canadian centers during a previously well-described epidemic to assess the hypothesis that subpopulations of this lineage are associated with adverse clinical outcomes. The authors' key finding, however, was that MLVA genotyping grouped infections closely with associated hospital centers; CDI severity was not associated with any particular sublineage by MLVA. While the study does not support any causal inferences about strain-specific virulence of CDI, it does highlight the power of MLVA, a genotyping tool that remains valuable in tracking the geospatial transmission dynamics of CDI.

The role of fungi in C. difficile infection: An underappreciated transkingdom interaction

Novel culture independent technologies have further elucidated the composition of the human mycobiome, though the role of fungi in human health and disease remains largely unknown. Recent studies have suggested conflicting roles for fungi in the gastrointestinal tract, underscoring the complexity of the interactions between the mycobiome, its bacterial counterpart, and the host. One key example is the observation that fungal taxa are overrepresented in patients with Clostridioides difficile infection (CDI), suggesting a role for fungi in this disease. Recent studies in murine models have demonstrated the ability of the commensal fungus Candida albicans to alter the course of CDI, supporting the notion that fungi play a role in this infection. This review summarizes current data on fungi and CDI, and shows that views of the dysbiotic state that is central to the pathogenesis of CDI are incomplete without consideration of the mycobiome.

Extended-pulsed fidaxomicin versus vancomycin for Clostridium difficile infection: EXTEND study subgroup analyses

Poor outcomes following Clostridium difficile infection (CDI) have been associated with advanced age, presence of cancer and C. difficile PCR-ribotype 027. The impact of baseline risk factors on clinical outcomes was evaluated using data from the EXTEND study, in which rate of sustained clinical cure (SCC) in the overall population was significantly higher with an extended-pulsed fidaxomicin (EPFX) regimen than with vancomycin. Patients aged ≥ 60 years received EPFX (fidaxomicin 200 mg twice daily, days 1–5; once daily on alternate days, days 7–25) or vancomycin (125 mg four times daily, days 1–10). We analysed outcomes by advanced age, cancer diagnosis, CDI severity, prior CDI occurrence and infection with PCR-ribotype 027. The primary endpoint was SCC 30 days after end of treatment (EOT; clinical response at test-of-cure with no subsequent recurrence). SCC rates 30 days after EOT did not differ significantly between EPFX (124/177, 70.1%) and vancomycin (106/179, 59.2%) regardless of age, cancer diagnosis, CDI severity and prior CDI. In patients with PCR-ribotype 027, SCC rate 30 days after EOT was significantly higher with EPFX (20/25, 80%) than with vancomycin (9/22, 40.9%) (treatment difference, 39.1%; 95% CI, 13.2–64.9; P = 0.006). Subgroup analyses from the EXTEND study suggest that EPFX is efficacious as a potential treatment for CDI regardless of age, cancer diagnosis, infection with PCR-ribotype 027, CDI severity or prior CDI. ClinicalTrials.gov identifier: NCT02254967.

Faecal microbiota transplantation for Clostridium difficile infection using a lyophilized inoculum from non-related donors: A case series involving 19 patients

Faecal microbiota transplantation (FMT) has been reported to be effective in treating relapsing of refractory Clostridium difficile infections, although some practical barriers are limiting its widespread use. In this study, our objective was to evaluate the rate of resolution of diarrhea following administration of lyophilized and resolved FMT via a nasogastric (NG) tube. We recruited 19 patients suffered from laboratory-confirmed C. difficile infection. Each of them was treated by lyophilized and resolved inoculum through a NG tube. One participant succumbed following the procedure due to unrelated diseases. Out of 18 cases, 15 patients reportedly experienced a resolution of the symptoms. One patient was treated with another course of antibiotics, and two of the non-responders were successfully retreated with another course of FMT utilizing a lyophilized inoculum. Notably, no significant adverse activities were observed. In accordance to our clinical experiences, a patient will likely benefit from FMT treatment including lyophilized inoculum.

Five years of fecal microbiota transplantation - an update of the Israeli experience

AIM

To evaluate and describe the efficacy of fecal microbiota transplantation (FMT) for Clostridium difficile infection (CDI) in a national Israeli cohort.

METHODS

All patients who received FMT for recurrent (recurrence within 8 wk of the previous treatment) or refractory CDI from 2013 through 2017 in all the five medical centers in Israel currently performing FMT were included. Stool donors were screened according to the Israeli Ministry of Health guidelines. Clinical and laboratory data of patients were collected from patients’ medical files, and they included indications for FMT, risk factors for CDI and disease severity. Primary outcome was FMT success (at least 2 mo free of CDI-related diarrhea post-FMT). Secondary outcomes included initial response to FMT (cessation of diarrhea within 7 d) and recurrence at 6 mo.

RESULTS

There were 111 FMTs for CDI, with a median age of 70 years [interquartile range (IQR): 53-82], and 42% (47) males. Fifty patients (45%) were treated via the lower gastrointestinal (LGI, represented only by colonoscopy) route, 37 (33%) via capsules, and 24 (22%) via the upper gastrointestinal (UGI) route. The overall success rate was 87.4% (97 patients), with no significant difference between routes of administration (P = 0.338). In the univariant analysis, FMT success correlated with milder disease (P = 0.01), ambulatory setting (P < 0.05) and lower Charlson comorbidity score (P < 0.05). In the multivariant analysis, only severe CDI [odd ratio (OR) = 0.14, P < 0.05] and inpatient FMT (OR = 0.19, P < 0.05) were each independently inversely related to FMT success. There were 35 (32%) patients younger than 60 years of age, and 14 (40%) of them had a background of inflammatory bowel disease.

CONCLUSION

FMT is a safe and effective treatment for CDI, with capsules emerging as a successful and well-tolerated route. Severe CDI is less likely to respond to FMT.

Pharmacologic Approach to Management of Clostridium difficile Infection

Clostridium difficile is a gram-positive, anaerobic, spore-forming bacterium that is the leading cause of nosocomial infections in hospitals in the United States. Critically ill patients are at high risk for C. difficile infection (CDI) and face potentially detrimental effects, including prolonged hospitalization, risk of recurrent disease, complicated surgery, and death. CDI requires a multidisciplinary approach to decrease hospital transmission and improve treatment outcomes. This article briefly reviews the current literature and guideline recommendations for treatment and prevention of CDI, with a focus on antibiotic treatment considerations including dosing, routes of administration, efficacy data, adverse effects, and monitoring parameters.

Association between Clostridioides difficile ribotypes, restriction endonuclease analysis types, and toxin gene expression

OBJECTIVES

Clostridioides difficile strains cause severe infection. Previous studies suggested that the virulence of C. difficile is dependent on ribotype; however, this hypothesis is still controversial. We aim to investigate the relationship between ribotypes, restriction endonuclease analysis (REA) types, and toxin gene expression in C. difficile strains.

METHODS

We utilized 53 clinical C. difficile strains. All strains were assigned a molecular strain type using PCR ribotyping and REA typing and classified into 17 ribotypes and six REA types. The expression of toxin genes (tcdA, tcdB, and cdtB) in C. difficile strains were quantified by real-time PCR using each specific primer set, and expression was normalized to that of the housekeeping gene rpoA.

RESULTS

All 53 strains expressed tcdB and four strains expressed cdtB. Five strains did not express tcdA. Most ribotype and REA type strains expressed tcdA and tcdB similar to the BAA-1870 strain. In cdtB-positive strains, the cdtB expression levels were similar to those in the BAA-1870 strain. tcdA and tcdB expression levels were similar in the cdtB-positive and cdtB-negative strains.

CONCLUSION

Toxin gene expression was not associated with the ribotype. Production of binary toxin C. difficile transferase was not related to tcdA and tcdB expression levels.

Risk factors for recurrence in patients with Clostridium difficile infection due to 027 and non-027 ribotypes

OBJECTIVES

Our objective was to evaluate factors associated with recurrence in patients with 027+ and 027- Clostridium difficile infection (CDI).

METHODS

Patients with CDI observed between January and December 2014 in six hospitals were consecutively included in the study. The 027 ribotype was deduced by the presence of tcdB, tcdB, cdt genes and the deletion Δ117 in tcdC (Xpert® C. difficile/Epi). Recurrence was defined as a positive laboratory test result for C. difficile more than 14 days but within 8 weeks after the initial diagnosis date with reappearance of symptoms. To identify factors associated with recurrence in 027+ and 027- CDI, a multivariate analysis was performed in each patient group. Subdistributional hazard ratios (sHRs) and 95% confidence intervals (95%CIs) were calculated.

RESULTS

Overall, 238 patients with 027+ CDI and 267 with 027- CDI were analysed. On multivariate analysis metronidazole monotherapy (sHR 2.380, 95%CI 1.549-3.60, p <0.001) and immunosuppressive treatment (sHR 3.116, 95%CI 1.906-5.090, p <0.001) were factors associated with recurrence in patients with 027+ CDI. In this patient group, metronidazole monotherapy was independently associated with recurrence in both mild/moderate (sHR 1.894, 95%CI 1.051-3.410, p 0.033) and severe CDI (sHR 2.476, 95%CI 1.281-4.790, p 0.007). Conversely, non-severe disease (sHR 3.704, 95%CI 1.437-9.524, p 0.007) and absence of chronic renal failure (sHR 16.129, 95%CI 2.155-125.000, p 0.007) were associated with recurrence in 027- CDI.

CONCLUSIONS

Compared to vancomycin, metronidazole monotherapy appears less effective in curing CDI without relapse in the 027+ patient group, independently of disease severity.

Presence of multiple Clostridium difficile strains at primary infection is associated with development of recurrent disease

Recurrence of Clostridium difficile infection (CDI) places a major burden on the healthcare system. Previous studies have suggested that specific C. difficile strains, or ribotypes, are associated with severe disease and/or recurrence. However, in some patients a new strain is detected in subsequent infections, complicating longitudinal studies focused on strain differences that may contribute to disease outcome. We examined ribotype composition over time in patients who did or did not develop recurrence to examine infection with multiple C. difficile ribotypes (mixed infection), during the course of infection. Using a retrospective patient cohort, we isolated and ribotyped a median of 36 C. difficile colonies from 61 patients (105 total samples) at initial infection, recurrence (a second case of CDI within 15-56 days of initial infection), and reinfection (a second case of CDI after 56 days of initial infection). We observed mixed infection in 78.6% of samples at initial infection in patients who went on to develop recurrence compared to 18.1% of patients who did not, and mixed infection remained associated with subsequent recurrence after adjusting for gender and prior antibiotic exposure (OR 3.5, 95% CI 1.3-9.4, P = .015). In patients who were sampled longitudinally (44 consecutive events in 32 patients), the dominant ribotype changed in 31.8% of consecutive samples and the newly dominant ribotype was not detected in prior samples from that patient. Our results suggest that mixed C. difficile infection is more prevalent than previously demonstrated and potentially a marker of susceptibility to recurrence.

An Observational Cohort Study of Clostridium difficile Ribotype 027 and Recurrent Infection

CDI is a major public health issue, with over 400,000 cases per year in the United States alone. Recurrent CDI is common, occurring in approximately one in five individuals after a primary episode. Although interventions exist that could reduce the risk of recurrence, deployment in all patients is limited by cost, invasiveness, and/or an undetermined long-term safety profile. Thus, clinicians need risk stratification tools to properly allocate treatments. Because prior research on clinical predictors has failed to yield a reliable, reproducible, and effective predictive model to assist treatment decisions, accurate biomarkers of recurrence would be of great value. This study tested whether PCR ribotype independently predicted rCDI, and the data build upon prior research in showing that ribotype 027 is associated with rCDI.

Recurrent Clostridium difficile infection (rCDI) frequently complicates recovery from CDI. Accurately predicting rCDI would allow judicious allocation of limited resources, but published models have met with limited success. Thus, biomarkers predictive of recurrence have been sought. This study tested whether PCR ribotype independently predicted rCDI. Stool samples from nonpregnant inpatients ≥18 years of age with diarrhea were included from October 2010 to January 2013 after the patients tested positive for C. difficile in the clinical microbiology laboratory. Per guidelines, the rCDI was defined as a positive test for C. difficile at >2 weeks but ≤8 weeks from the index episode. For each sample, a single colony of C. difficile was isolated by anaerobic culture, confirmed to be toxigenic by PCR, and ribotyped. Simple logistic regression and multiple logistic regression were used to model the primary outcome of rCDI, incorporating a wide range of clinical parameters. In total, 927 patients with 968 index episodes of CDI were included, with 110 (11.4%) developing rCDI. Age and use of proton pump inhibitors or concurrent antibiotics did not increase the risk of rCDI. Low serum bilirubin levels and ribotype 027 were associated with increased risk of rCDI on unadjusted analysis, with health care-associated CDI being inversely associated. In the final multivariable model, ribotype 027 was the strongest independent predictor of rCDI (odds ratio, 2.17; 95% confidence interval, 1.33 to 3.56; P = 0.002). Ribotype 027 is an independent predictor of rCDI.

IMPORTANCE CDI is a major public health issue, with over 400,000 cases per year in the United States alone. Recurrent CDI is common, occurring in approximately one in five individuals after a primary episode. Although interventions exist that could reduce the risk of recurrence, deployment in all patients is limited by cost, invasiveness, and/or an undetermined long-term safety profile. Thus, clinicians need risk stratification tools to properly allocate treatments. Because prior research on clinical predictors has failed to yield a reliable, reproducible, and effective predictive model to assist treatment decisions, accurate biomarkers of recurrence would be of great value. This study tested whether PCR ribotype independently predicted rCDI, and the data build upon prior research in showing that ribotype 027 is associated with rCDI.

Management of Recurrent Clostridium difficile Infection During Intensive Chemotherapy and Stem Cell Transplantation for Leukemia: Case with Literature Review

Immunocompromised patients undergoing chemotherapy for hematologic malignancy and hematopoietic stem cell transplant (HSCT) recipients are at increased risk of Clostridium difficile (C. difficile) infection (CDI). The recurrence of infection and its associated morbidity and mortality are due to multiple risk factors. Diarrhea is common in HSCT recipients, but the diagnosis of diarrhea caused by CDI is a therapeutic challenge due to frequent Clostridium difficile colonization with diarrhea secondary to non-infectious causes. The high recurrence rate is a significant challenge in the treatment of immunocompromised patients. Close monitoring of the patients, timely diagnosis, preventive measures, treatment with antibiotics, and the removal of offending agents can help in the management and cure of the disease. We review the literature on management and describe a patient with acute lymphoblastic leukemia (ALL) with multiple recurrences of CDI during leukemia therapy and allogeneic stem cell transplantation for leukemia.

Recent Progress for the Effective Prevention and Treatment of Recurrent Clostridium difficile Infection

Recurrence occurs in approximately 25% of all cases of Clostridium difficile infection (CDI) and poses a unique clinical challenge. Traditionally, treatment options of CDI have been limited to regimes of established antibiotics (eg, pulsed/tapered vancomycin) but faecal transplantation is emerging as a useful alternative. In recent years, promising new strategies have emerged for effective prevention of recurrent CDI (rCDI) including new antimicrobials (eg, fidaxomicin) and monoclonal antibodies (eg, bezlotoxumab). Despite promising progress in this area, obstacles remain for making the best use of these resources due to uncertainty over patient selection. This commentary describes the current epidemiology of rCDI, its clinical impact and risk factors, some of the measures used for treating and preventing rCDI, and some of the emerging treatment options. It then describes some of the obstacles that need to be overcome.

Comparison of Different Strategies for Providing Fecal Microbiota Transplantation to Treat Patients with Recurrent Clostridium difficile Infection in Two English Hospitals: A Review

Fecal microbiota transplant (FMT) has emerged as a highly efficacious treatment for difficult cases of refractory and/or recurrent Clostridium difficile infection (CDI). There have been many well-conducted randomized controlled trials and thousands of patients reported in case series that describe success rates of approximately 90% following one or more FMT. Although the exact mechanisms of FMT have yet to be fully elucidated, replacement or restoration of a 'normal' microbiota (or at least a microbiota resembling those who have never had CDI) appears to have a positive effect on the gut dysbiosis that is thought to exist in these patients. Furthermore, despite being aesthetically unappealing, this 'ultimate probiotic' is a particularly attractive solution to a difficult problem that avoids repeated courses of antibiotics. The lack of clarity about the exact mechanism of action and the 'active ingredient' of FMT (e.g., individual or communities of bacteria, bacteriophage, or bioactive molecules such as bile acids) has hindered the ability to produce a standardized and well-characterized FMT product. There is no standard method to produce material for FMT, and there are a multitude of factors that can vary between institutions that offer this therapy. Only a few studies have directly compared clinical efficacy in groups of patients who have been treated with FMT prepared differently (e.g., fresh vs. frozen) or administered by different route (e.g., by nasojejunal tube, colonoscopy or by oral administration of encapsulated product). More of these studies should be undertaken to clarify the superiority or otherwise of these variables. This review describes the methods and protocols that two English NHS hospitals independently adopted over the same time period to provide FMT for patients with recurrent CDI. There are several fundamental differences in the methods used, including selection and testing of donors, procedures for preparation and storage of material, and route of administration. These methods are described in detail in this review highlighting differing practice. Despite these significant methodological variations, clinical outcomes in terms of cure rate appear to be remarkably similar for both FMT providers. Although both hospitals have treated only modest numbers of patients, these findings suggest that many of the described differences may not be critical factors in influencing the success of the procedure. As FMT is increasingly being proposed for a number of conditions other than CDI, harmonization of methods and techniques may be more critical to the success of FMT, and thus it will be important to standardize these as far as practically possible.

PCR ribotyping and antimicrobial susceptibility testing of isolates of Clostridium difficile cultured from toxin-positive diarrheal stools of patients receiving medical care in Canadian hospitals: the Canadian Clostridium difficile Surveillance Study (CAN-DIFF) 2013-2015

Clostridium difficile toxin-positive diarrheal stool specimens submitted to eight Canadian hospital laboratories from 2013 to 2015 were cultured. Polymerase chain reaction ribotyping of isolates was performed using an internationally standardized, high-resolution capillary gel-based electrophoresis protocol and antimicrobial susceptibility testing conducted by CLSI-defined agar dilution (M11-A8, 2012). Among the 1310 isolates of C. difficile cultured, 141 different ribotypes were identified; the most common ribotypes were 027 (24.5% of isolates), 014 (7.7%), 020 (6.6%), 106 (6.1%), and 002 (4.6%). Ribotype 027 was the commonest ribotype in all geographic regions of Canada and was more frequently isolated from patients aged ≥80 years (40.6%) than younger patients (P<0.00001). Ribotype 027 isolates were frequently moxifloxacin-resistant (92.2% of isolates) and multidrug-resistant (49.5%). Fidaxomicin demonstrated the greatest in vitro potency (lowest MIC₉₀, 0.5 μg/mL; lowest maximum MIC, 2 μg/mL) of eight antimicrobial agents tested and was the most active agent against each of the five commonest ribotypes (MIC₉₀, 0.25-1 μg/mL).

Early Results of Fecal Microbial Transplantation Protocol Implementation at a Community-based University Hospital

Introduction:

Clostridium difficile (CD) is a serious and increasingly prevalent healthcare-associated infection. The pathogenesis of CD infection (CDI) involves the acquisition of CD with a concurrent disruption of the native gut flora. Antibiotics are a major risk although other contributing factors have also been identified. Clinical management combines discontinuation of the offending antibiotic, initiation of CD-specific antibiotic therapy, probiotic agent use, fecal microbiota transplantation (FMT), and surgery as the “last resort” option. The aim of this study is to review short-term clinical results following the implementation of FMT protocol (FMTP) at our community-based university hospital.

Methods:

After obtaining Institutional Review Board and Infection Control Committee approvals, we implemented an institution-wide FMTP for patients diagnosed with CDI. Prospective tracking of all patients receiving FMT between July 1, 2015, and February 1, 2017, was conducted using REDCap™ electronic data capture system. According to the FMTP, indications for FMT included (a) three or more CDI recurrences, (b) two or more hospital admissions with severe CDI, or (c) first episode of complicated CDI (CCDI). Risk factors for initial infection and for treatment failure were assessed. Patients were followed for at least 3 months to monitor for cure/failure, relapse, and side effects. Frozen 250 mL FMT samples were acquired from OpenBiome (Somerville, MA, USA). After 4 h of thawing, the liquid suspension was applied using colonoscopy, beginning with terminal ileum and proceeding distally toward mid-transverse colon. Monitored clinical parameters included disease severity (Hines VA CDI Severity Score or HVCSS), concomitant medications, number of FMT treatments, non-FMT therapies, cure rates, and mortality. Descriptive statistics were utilized to outline the study results.

Results:

A total of 35 patients (mean age 58.5 years, 69% female) were analyzed, with FMT-attributable primary cure achieved in 30/35 (86%) cases. Within this subgroup, 2/30 (6.7%) patients recurred and were subsequently cured with long-term oral vancomycin. Among five primary FMT failures (14% total sample), 3 (60%) achieved medical cure with long-term oral vancomycin therapy and 2 (40%) required colectomy. For the seven patients who either failed FMT or recurred, long-term vancomycin therapy was curative in all but two cases. For patients with severe CDI (HVCSS ≥3), primary and overall cure rates were 6/10 (60%) and 8/10 (80%), respectively. Patients with CCDI (n = 4) had higher HVCSS (4 vs. 3) and a mortality of 25%. Characteristics of patients who failed initial FMT included older age (70 vs. 57 years), female sex (80% vs. 67%), severe CDI (80% vs. 13%), and active opioid use during the initial infection (60% vs. 37%) and at the time of FMT (60% vs. 27%). The most commonly reported side effect of FMT was loose stools.

Conclusions:

This pilot study supports the efficacy and safety of FMT administration for CDI in the setting of a community-based university hospital. Following FMTP implementation, primary (86%) and overall (94%) nonsurgical cure rates were similar to those reported in other studies. The potential role of opioids as a modulator of CDI warrants further clinical investigation.

Evidence-Based Practice in the Treatment for Antibiotic-Associated Diarrhea in the Intensive Care Unit

Unit nurses provide care to patients with serious health conditions. Often antibiotics are recommended to fight infections. Sometimes patients are on proton pump inhibitors (PPI). Antibiotics and PPIs may lead to diarrhea, causing the patient more discomfort, and possibly leading to a more serious infection. One serious infection is caused by Clostridium difficile, which causes death in some cases. About 75% of patients on antibiotics may not need antibiotics. Several studies showed less diarrhea in patients on probiotics. However, probiotics cause harm to some patients, which needs to be considered. Nurses need to ensure that antibiotic stewardship is followed.