Trends in U.S. Burden of Clostridioides difficile Infection and Outcomes

Development of multi-epitope mRNA vaccine against Clostridioides difficile using reverse vaccinology and immunoinformatics approaches

Clostridioides difficile (C. difficile), as the major pathogen of diarrhea in healthcare settings, has become increasingly prevalent within community populations, resulting in significant morbidity and mortality. However, the therapeutic options for Clostridioides difficile infection (CDI) remain limited, and as of now, no authorized vaccine is available to combat this disease. Therefore, the development of a novel vaccine against C. difficile is of paramount importance. In our study, the complete proteome sequences of 118 strains of C. difficile were downloaded and analyzed. We found four antigenic proteins that were highly conserved and can be used for epitope identification. We designed two vaccines, WLcd1 and WLcd2, that contain the ideal T-cell and B-cell epitopes, adjuvants, and the pan HLA DR-binding epitope (PADRE) sequences. The biophysical and chemical assessments of these vaccine candidates indicated that they were suitable for immunogenic applications. Molecular docking analyses revealed that WLcd1 bonded with higher affinity to Toll-like receptors (TLRs) than WLcd2. Furthermore, molecular dynamics (MD) simulations, performed using Gmx_MMPBSA v1.56, confirmed the binding stability of WLcd1 with TLR2 and TLR4. The preliminary findings suggested that this multi-epitope vaccine could be a promising candidate for protection against CDI; however, experimental studies are necessary to confirm these predictions.

Therapeutics involved in managing initial and recurrent Clostridium difficile infection: An updated literature review

Clostridium difficile infection (CDI) has been increasing due to the effect of recurrent hospitalizations. The use of antibiotics has been shown to alter the gut microbiome and lead to CDIs. The treatment is limited to three major antibiotics; however, the incidence of recurrent CDIs has been increasing and drug resistance is a major concern. This aspect is a growing concern in modern medicine especially in the elderly population, critical care patients, and immunocompromised individuals who are at high risk of developing CDIs. Clostridium difficile can lead to various complications including septic shock and fulminant colitis that could prove to be lethal in these patients. Newer modalities of treatment have been developed including bezlotoxumab, a monoclonal antibody and fecal microbiota transplant. There have been studies showing asymptomatic carriers and drug resistance posing a major threat to the healthcare system. Newer treatment options are being studied to treat and prevent CDIs. This review will provide an insight into the current treatment modalities, prevention and newer modalities of treatment and challenges faced in the treatment of CDIs.

Fecal Microbiota, Live-jslm for the Prevention of Recurrent Clostridioides difficile Infection : Subgroup Analysis of PUNCH CD2 and PUNCH CD3

GOALS

To assess fecal microbiota, live-jslm (REBYOTA, abbreviated as RBL, formerly RBX2660) efficacy and safety in participants grouped by recurrent Clostridioides difficile infection (rCDI) risk factors and treatment-related variables.

BACKGROUND

RBL is the first microbiota-based live biotherapeutic approved by the US Food and Drug Administration for the prevention of rCDI in adults after antibiotic treatment for rCDI.

STUDY

Treatment success rates across subgroups for PUNCH CD3 (NCT03244644) were estimated using a Bayesian hierarchical model, borrowing data from PUNCH CD2 (NCT02299570). Treatment-emergent adverse events were summarized for the double-blind treatment period within 8 weeks.

RESULTS

Treatment differences between RBL and placebo at 8 weeks were similar to the total population for most subgroups. Treatment effect sizes were similar between CDI tests, higher for oral vancomycin courses >14 days versus ≤14 days and higher for antibiotic washout periods of 3 days versus ≤2 days. The largest reductions in the rate of rCDI with RBL versus placebo were observed for participants with a 3-day CDI antibiotic washout period and participants with ≥4 previous CDI episodes. Most RBL-treated participants experienced TEAEs that were mild or moderate in severity and related to preexisting conditions.

CONCLUSION

This analysis provides further evidence of RBL efficacy and safety across subgroups, including those at high risk for rCDI.

Occurrence and trends of Clostridioides difficile infections in hospitalized patients: a prospective multi-centre cohort study in six German university hospitals, 2016-2020

BACKGROUND

For Clostridioides difficile infections (CDIs) in Germany no longitudinal multi-centre studies with standardized protocols for diagnosing CDI are available. Recent evaluations of general surveillance databases in Germany indicate a downward trend in CDI rates. We aimed to describe the actual burden and trends of CDI in German university hospitals from 2016 to 2020.

METHODS

Our study was a prospective multi-centre study covering six German university hospitals. We report the data in total, stratified by year, by medical specialty as well as by CDI severity. Multi-variable regression analyses were performed to assess risk factors for severe CDI.

RESULTS

We registered 3780 CDI cases among 1,436,352 patients. The median length of stay (LOS) of CDI cases was 20 days (interquartile range 11-37) compared with a general LOS of 4.2 days. In-hospital all-cause mortality in CDI patients was 11.7% (N = 444/3780), while mortality attributed to CDI was 0.4% (N = 16/3761). CDI recurrence rate was comparatively low at 7.2%. The incidence density of severe healthcare-associated healthcare onset (HAHO)-CDI showed a significant decrease from 2.25/10,000 patient days (pd) in 2016 to 1.49/10,000 pd in 2020 (trend calculation P=0.032).

CONCLUSIONS

Compared with a European point-prevalence study in 2013/2014, where overall CDI incidence density was 11.2 cases/10,000 pd in Germany (EUCLID), we see in our study halved overall CDI rates of 5.6 cases/10,000 pd in 2020. Our study shows current data on the distribution of CDI cases in German university hospitals and thus provides international comparative data on the key indicators of CDI.

Clostridioides difficile infection epidemiology during the COVID-19 pandemic in Greece

Aim: The aim was to highlight the incidence and epidemiology of C. difficile infections (CDI) in a tertiary Greek hospital during the COVID-19 pandemic.Methods: A single-center prospective observational cohort study was conducted (October 2021 until April 2022). 125 C. difficile isolates were cultured from hospitalized patients stool samples and screened by PCR for toxin A (tcdA), toxin B (tcdB), binary toxin (cdtA and cdtB) genes and the regulating gene of tcdC.Results: The incidence of CDI increased to 13.1 infections per 10,000 bed days. The most common PCR ribotypes identified included hypervirulent RT027-related RT181 (73.6%), presumably hypervirulent RT126 (8.0%) and toxin A negative RT017 (7.2%).Conclusion: Although the incidence of CDI increased significantly, the CDI epidemiology remained stable.

Preferences for a Clostridioides difficile vaccine among adults in the United States

INTRODUCTION

Clostridioides difficile (C.diff) infection (CDI) causes significant morbidity and mortality among older adults. Vaccines to prevent CDI are in development; however, data on the target population's preferences are needed to inform vaccination recommendations in the United States (US). This study assessed US adults' willingness to receive a C.diff vaccine and examined how vaccine attributes influence their choices.

METHODS

A cross-sectional online survey with a discrete choice experiment (DCE) was conducted among US adults aged ≥50 years. DCE attributes included effectiveness, duration of protection, reduction in symptom severity, out-of-pocket (OOP) costs, number of doses, and side effects. The DCE included 11 choice tasks, each with two hypothetical vaccine profiles and an opt-out (i.e., no vaccine). Attribute-level preference weights were estimated using hierarchical Bayesian modeling. Attribute relative importance (RI) was compared between select subgroups.

RESULTS

Of 1216 adults in the analyses, 29.9% reported they knew either 'a little' (20.7%) or 'a lot' (9.2%) about C.diff before the study. A C.diff vaccine was chosen 58.0% of the time (vs. opt-out) across choice tasks. It was estimated that up to 75.0% would choose a vaccine when OOP was $0. Those who were immunocompromised/high-risk for CDI (vs. not) more frequently chose a C.diff vaccine. Decreases in OOP costs (RI = 56.1), improvements in vaccine effectiveness (RI = 17.7), and reduction in symptom severity (RI = 10.3) were most important to vaccine choice. The rank ordering of attributes by importance was consistent across subgroups.

CONCLUSION

OOP cost, improvements in vaccine effectiveness, and reduction in CDI severity were highly influential to vaccine selection. Most adults aged ≥50 years were receptive to a C.diff vaccine, especially with little-to-no OOP cost, suggesting that mandating insurance coverage of vaccination with no copayment may increase uptake. The limited awareness about C.diff among adults presents an opportunity for healthcare providers to educate their patients about CDI prevention.

Development and evaluation of a rapid visual loop-mediated isothermal amplification assay for the tcdA gene in Clostridioides difficile detection

Background

The tcdA gene codes for an important toxin produced by Clostridioides difficile (C. difficile), but there is currently no simple and cost-effective method of detecting it. This article establishes and validates a rapid and visual loop-mediated isothermal amplification (LAMP) assay for the detection of the tcdA gene.

Methods

Three sets of primers were designed and optimized to amplify the tcdA gene in C. difficile using a LAMP assay. To evaluate the specificity of the LAMP assay, C. difficile VPI10463 was used as a positive control, while 26 pathogenic bacterial strains lacking the tcdA gene and distilled water were utilized as negative controls. For sensitivity analysis, the LAMP assay was compared to PCR using ten-fold serial dilutions of DNA from C. difficile VPI10463, ranging from 207 ng/µl to 0.000207 pg/µl. The tcdA gene of C.difficile was detected in 164 stool specimens using both LAMP and polymerase chain reaction (PCR). Positive and negative results were distinguished using real-time monitoring of turbidity and chromogenic reaction.

Results

At a temperature of 66 °C, the target DNA was successfully amplified with a set of primers designated, and visualized within 60 min. Under the same conditions, the target DNA was not amplified with the tcdA12 primers for 26 pathogenic bacterial strains that do not carry the tcdA gene. The detection limit of LAMP was 20.700 pg/µl, which was 10 times more sensitive than that of conventional PCR. The detection rate of tcdA in 164 stool specimens using the LAMP method was 17% (28/164), significantly higher than the 10% (16/164) detection rate of the PCR method (X2 = 47, p < 0.01).

Conclusion

LAMP method is an effective technique for the rapid and visual detection of the tcdA gene of C. difficile, and shows potential advantages over PCR in terms of speed, simplicity, and sensitivity. The tcdA-LAMP assay is particularly suitable for medical diagnostic environments with limited resources and is a promising diagnostic strategy for the screening and detection of C. difficile infection in populations at high risk.

Elucidating human gut microbiota interactions that robustly inhibit diverse Clostridioides difficile strains across different nutrient landscapes

The human gut pathogen Clostridioides difficile displays substantial inter-strain genetic variability and confronts a changeable nutrient landscape in the gut. We examined how human gut microbiota inter-species interactions influence the growth and toxin production of various C. difficile strains across different nutrient environments. Negative interactions influencing C. difficile growth are prevalent in an environment containing a single highly accessible resource and sparse in an environment containing C. difficile-preferred carbohydrates. C. difficile toxin production displays significant community-context dependent variation and does not trend with growth-mediated inter-species interactions. C. difficile strains exhibit differences in interactions with Clostridium scindens and the ability to compete for proline. Further, C. difficile shows substantial differences in transcriptional profiles in co-culture with C. scindens or Clostridium hiranonis. C. difficile exhibits massive alterations in metabolism and other cellular processes in co-culture with C. hiranonis, reflecting their similar metabolic niches. C. hiranonis uniquely inhibits the growth and toxin production of diverse C. difficile strains across different nutrient environments and robustly ameliorates disease severity in mice. In sum, understanding the impact of C. difficile strain variability and nutrient environments on inter-species interactions could help improve the effectiveness of anti-C. difficile strategies.

Deep learning-based prediction of Clostridioides difficile infection caused by antibiotics using longitudinal electronic health records

Clostridioides difficile infection (CDI) is a major cause of antibiotic-associated diarrhea and colitis. It is recognized as one of the most significant hospital-acquired infections. Although CDI can develop severe complications and spores of Clostridioides difficile can be transmitted by the fecal-oral route, CDI is occasionally overlooked in clinical settings. Thus, it is necessary to monitor high CDI risk groups, particularly those undergoing antibiotic treatment, to prevent complications and spread. We developed and validated a deep learning-based model to predict the occurrence of CDI within 28 days after starting antibiotic treatment using longitudinal electronic health records. For each patient, timelines of vital signs and laboratory tests with a 35-day monitoring period and a patient information vector consisting of age, sex, comorbidities, and medications were constructed. Our model achieved the prediction performance with an area under the receiver operating characteristic curve of 0.952 (95% CI: 0.932-0.973) in internal validation and 0.972 (95% CI: 0.968-0.975) in external validation. Platelet count and body temperature emerged as the most important features. The risk score, the output value of the model, exhibited a consistent increase in the CDI group, while the risk score in the non-CDI group either maintained its initial value or decreased. Using our CDI prediction model, high-risk patients requiring symptom monitoring can be identified. This could help reduce the underdiagnosis of CDI, thereby decreasing transmission and preventing complications.

Fecal Microbiota, Live-jslm (RBL; REBYOTA®) for Prevention of Recurrent Clostridioides difficile Infection: What Gastroenterology Nurses Need to Know

Live biotherapeutic products (LBPs) such as fecal microbiota, live-jslm (RBL) are becoming more frequently administered in gastroentintestinal (GI) care settings. As a result, GI nurses must be knowledgeable about and skilled in their administration of LBPs. RBL is a single-dose, rectally-administered, microbiota-based LBP suspension indicated for prevention of recurrent Clostridioides difficile infection (rCDI). RBL contains a diverse set of micro-organisms, including Bacteroides spp., and is believed to restore a healthy gut microbiota to mitigate dysbiosis associated with rCDI. Patients do not require fasting, bowel preparation, or anesthesia prior to RBL administration. Administration takes approximately 5 minutes and can be given by any health care professional (e.g., nurses) in any care setting. Nurses also play an important role in educating patients and caregivers about these products and the disease. Collectively, improved familiarity with LBPs and their proper use among nurses can contribute to successful prevention of rCDI in their patients.

Chemical optimization and derivatization of micrococcin p2 to target multiple bacterial infections: new antibiotics from thiopeptides

Antimicrobial resistance poses a significant threat to humanity, and the development of new antibiotics is urgently needed. Our research has focused on thiopeptide antibiotics such as micrococcin P2 (MP2) and derivatives thereof as new anti-infective agents. Thiopeptides are sulfur-rich, structurally complex substances that exhibit potent activity against Gram-positive pathogens and Mycobacteria species, including clinically resistant strains. The clinical development of thiopeptides has been hampered by the lack of efficient synthetic platforms to conduct detailed structure-activity relationship studies of these natural products. The present contribution touches upon efficient synthetic routes to MP2 that laid the groundwork for clinical translation. The medicinal chemistry campaign on MP2 has been guided by computational molecular dynamic simulations and parallel investigations to improve drug-like properties, such as enhancing the aqueous solubility and optimizing antibacterial activity. Such endeavors have enabled identification of promising lead compounds, AJ-037 and AJ-206, against Mycobacterium avium complex (MAC). Extensive in vitro studies revealed that these compounds exert potent activity against MAC species, a subspecies of non-tuberculous mycobacteria (NTM) that proliferate inside macrophages. Two additional pre-clinical candidates have been identified: AJ-024, for the treatment of Clostridioides difficile infections, and AJ-147, for methicillin-resistant Staphylococcus aureus impetigo. Both compounds compare quite favorably with current first-line treatments. In particular, the ability of AJ-147 to downregulate pro-inflammatory cytokines adds a valuable dimension to its clinical use. In light of above, these new thiopeptide derivatives are well-poised for further clinical development.

The Incidence of Clostridioides difficile Infection in the Post-COVID-19 Era in a Hospital in Northern Greece

Clostridioides difficile infection (CDI) has evolved to be the most significant cause of healthcare-associated diarrhoea and one of the leading representatives of healthcare-associated infections, with a high associated mortality. The aim of this retrospective study was to record the incidence rates and the epidemiological and clinical features of CDI in a large tertiary hospital of northern Greece in the years 2022-2023. All patients with CDI-compatible symptomatology and a positive CDI diagnostic test (GDH-glutamate dehydrogenase and toxin-positive FIA-Fluorescent Immuno-chromatography-SD Biosensor, and/or film array) were included (104 from a total of 4560 admitted patients). Their demographic, laboratory, and clinical data were recorded and analysed. The incidence of CDI in admitted patients was found to be higher than previous reports in the geographical area, reaching 54.6/10,000 patient days and following a rising trend over the course of the study. Thirty-day mortality was high (39.4%), potentially related to new emerging hypervirulent C. difficile strains. In view of the high prevalence of multidrug-resistant organisms in the region, and the significant mortality associated with this infection, these findings particularly point to the need for the implementation of organized surveillance and infection prevention protocols.

Emerging Clostridioides difficile ribotypes have divergent metabolic phenotypes

Clostridioides difficile is a gram-positive spore-forming pathogen that commonly causes diarrheal infections in the developed world. Although C. difficile is a genetically diverse species, certain ribotypes are overrepresented in human infections. It is unknown if metabolic adaptations are essential for the emergence of these epidemic ribotypes. Here, we tested carbon substrate utilization by 88 C. difficile isolates and looked for differences in growth between 22 ribotypes. By profiling clinical isolates, we assert that C. difficile is a generalist species capable of growing on a variety of carbon substrates. Further, C. difficile strains clustered by phylogenetic relationship and displayed ribotype-specific and clade-specific metabolic capabilities. Surprisingly, we observed that two emerging lineages, ribotypes 023 and 255, have divergent metabolic phenotypes. In addition, although C. difficile Clade 5 is the most evolutionary distant clade and often detected in animals, it displayed more robust growth on simple dietary sugars than Clades 1-4. Altogether, our results corroborate the generalist metabolic strategy of C. difficile and demonstrate lineage-specific metabolic capabilities. In addition, our approach can be adapted to the study of additional pathogens to ascertain their metabolic niches in the gut.

IMPORTANCE

The gut pathogen Clostridioides difficile utilizes a wide range of carbon sources. Microbial communities can be rationally designed to combat C. difficile by depleting its preferred nutrients in the gut. However, C. difficile is genetically diverse with hundreds of identified ribotypes and most of its metabolic studies were performed with lab-adapted strains. Here, we profiled carbon metabolism by a myriad of C. difficile clinical isolates. While the metabolic capabilities of these isolates clustered by their genetic lineage, we observed surprising metabolic divergence between two emerging lineages. We also found that the most genetically distant clade grew robustly on simple dietary sugars, posing intriguing questions about the adaptation of C. difficile to the human gut. Altogether, our results underscore the importance of considering the metabolic diversity of pathogens in the study of their evolution and the rational design of therapeutic interventions.

Antibiotic use and risk of Clostridioides difficile infection in patients with inflammatory bowel disease

BACKGROUND AND AIM

Patients with inflammatory bowel disease (IBD) have an increased risk of Clostridioides difficile infection (CDI) compared with those without IBD, which is worsened with antibiotic usage. While prior studies have shown a correlation between CDI development and certain classes of antibiotics, the IBD population has not been well represented. This study evaluates the rates of CDI with outpatient antibiotic use in patients with IBD.

METHODS

We conducted a retrospective cohort study composed of patients with IBD and compared the incidence of CDI in patients who received an outpatient prescription for antibiotics (6694 patients) against those without prescriptions (6025 patients) from 2014 to 2020 at our institution. We compared CDI rates based on nine antibiotic classes: penicillins, cephalosporins, sulfonamides, tetracyclines, macrolides, quinolones, clindamycin, metronidazole, and nitrofurantoin.

RESULTS

The risk of CDI was low (0.7%) but significantly higher for those with antibiotic exposure (0.9% vs 0.5%, P = 0.005) and had a positive correlation with a smoking history. The increased risk of CDI in the IBD population was attributable to the clindamycin and metronidazole classes (odds ratio = 4.7, 95% confidence interval: 1.9-11.9, P = 0.001; odds ratio = 3.6, 95% confidence interval: 2.1-6.2, P < 0.0001, respectively).

CONCLUSIONS

The use of clindamycin or metronidazole prescribed in an outpatient setting was associated with a statistically significant increased risk of CDI in patients with IBD. Although the association between clindamycin and CDI is a well-established and common finding, the association between metronidazole and CDI is unique in this study.

Is advanced age still a risk factor for recurrence of C. difficile infection in the era of new treatments?

BACKGROUND

Advanced age has been widely identified as a risk factor for recurrent Clostridioides difficile infection (CDI), but most related studies were performed before the introduction of novel therapies. The aim of this study was to compare CDI characteristics and outcomes in patients over and under 80 years old with CDI and their outcomes in the era of new treatments.

METHODS

This was a retrospective cohort study of patients diagnosed with CDI from January 2021 to December 2022 in an academic hospital. We compared recurrence and mortality at 12 weeks after the end of treatment. An extension of the Fine and Grey model adjusted for competing events was used to assess the effect of age on recurrence.

RESULTS

Four hundred seventy-six patients were considered to have CDI (320 in patients <80 years and 156 in ≥80 years). CDI in older patients was more frequently healthcare-associated and was more severe. Although the Charlson index was almost identical between populations, comorbidities clearly differed. New treatments (bezlotoxumab, fidaxomicin and faecal microbiota transplantation) were more frequently used in older patients without statistical significance (41.3% vs. 33.4%, P = .053). There were 69 (14.5%) recurrences, with no differences by age group after adjusting for competing events. Mortality was greater in the oldest (35.3%) than in the youngest (13.1%); P < .001.

CONCLUSIONS

No differences in CDI recurrence rates were found between age groups. However, there was a high mortality rate in patients ≥80 years old, which emphasises the urgent need to improve the prevention and treatment of CDI in this group.

Significant Publications on Infectious Diseases Pharmacotherapy in 2022

Purpose: To provide summarization of the most significant infectious diseases (ID) pharmacotherapy articles published in peer-reviewed literature in 2022. Summary: Members of the Houston Infectious Diseases Network (HIDN) nominated notable articles providing significant contributions to ID pharmacotherapy in 2022. Article nominations included those pertaining to general ID, as well as those including coronavirus disease 2019 (COVID-19), and human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) pharmacotherapy. A total of 71 articles were nominated by HIDN. Members: 68 articles pertaining to general ID pharmacotherapy and 3 articles focusing on HIV/AIDS. To aid selection of the most these most notable articles of 2022, a survey was created and distributed to members of the Society of Infectious Diseases Pharmacists (SIDP). Of the 153 SIDP members who participated in the survey, there were 128 recorded votes for the top 10 general ID pharmacotherapy articles and 30 votes recorded for the top HIV/AIDS article. The most notable publications are summarized. Conclusion: Post pandemic significant advances in antimicrobial stewardship and infectious disease states continues to occur in a world recently focused on the coronavirus disease 2019 (COVID-19) global pandemic. Continuous growth in publication of ID-related articles over the past year lends towards the aims of this review to aid clinicians in remaining current on key practice-changing ID pharmacotherapy publications from 2022.

The Changes in Broad-spectrum Antimicrobial Consumption during the COVID-19 Pandemic in a Japanese Acute Tertiary-care Hospital: An Interrupted Time-series Analysis

Objective The novel coronavirus disease 2019 (COVID-19) pandemic has spread worldwide, and hospitals in Japan have been forced to respond to the situation. This study evaluated the broad-spectrum antimicrobial use before and during the COVID-19 pandemic in an acute tertiary-care hospital. Methods This single-center, retrospective study was conducted between January 2019 and June 2021. Patients We reviewed patients treated with three broad-spectrum antipseudomonal agents: carbapenems, tazobactam/piperacillin, and cefepime. Monthly aggregated hospital antimicrobial consumption was measured as days of therapy (DOTs) per 1,000 patient-days, and the monthly incidences of Clostridioides difficile infection (CDI), multidrug-resistant Pseudomonas aeruginosa (MRPA), and carbapenemase-producing Enterobacteriaceae (CPE) were recorded. Results The median monthly carbapenem-DOTs during the pre-pandemic and pandemic era were 8.4 and 8.2 per 1,000 patient-days, respectively. A time-series analysis showed non-significant changes in the level between periods (coefficients: 2.08; 95% confidence interval [CI]: -2.9 to 7.0; p=0.44). No change in the trend of monthly carbapenem-DOTs was observed after intervention. No post-intervention changes in the incidence of MRPA or CPE were observed; however, the trend in the incidence of CDI per 1,000 patient-days significantly differed between the two periods (coefficient: -0.04; 95% CI: -0.07, 0.00; p=0.01), and a downward trend was observed in the monthly CDI incidence during the COVID-19 period. Conclusion The consumption of broad intravenous antimicrobial agents has not changed significantly during the pandemic. We need to maintain the quality of medical care, including antimicrobial stewardship, even in specialized resource-limited facilities during a pandemic.

IL-13 protects from Clostridioides difficile colitis

OBJECTIVES

Clostridioides difficile infection (CDI) is the leading hospital-acquired infection in North America. We have previously discovered that antibiotic disruption of the gut microbiota decreases intestinal IL-33 and IL-25 and increases susceptibility to CDI. We further found that IL-33 promotes protection through type 2 Innate Lymphoid Cells (ILC2s), which produce IL-13. However, the contribution of IL-13 to disease has never been explored.

METHODS

We used a validated model of CDI in mice, in which we neutralized via blocking antibodies, or administered recombinant protein, IL-13 to assess the role of this cytokine during infection using weight and clinical scores. Fluorescent activated cell sorting (FACS) was used to characterize myeloid cell population changes in response to IL-13 manipulation.

RESULTS

We found that administration of IL-13 protected, and anti-IL-13 exacerbated CDI. Additionally, we observed alterations to the monocyte/macrophage cells following neutralization of IL-13 as early as day three post infection. We also observed elevated accumulation of myeloid cells by day four post-infection following IL-13 neutralization. Neutralization of the decoy receptor, IL-13Rα2, resulted in protection from disease, likely through increased available endogenous IL-13.

CONCLUSIONS

Our data highlight the protective role of IL-13 in protecting from more severe CDI and the association of poor responses with a dysregulated monocyte-macrophage compartment. These results increase our understanding of type 2 immunity in CDI and may have implications for treating disease in patients.

More than a new name: Updates in the management of Clostridioides difficile infection

ABSTRACT

Infections from Clostridioides difficile (often called C. diff) have long presented challenges for both patients and clinicians. Traditionally, C. diff has been considered a nosocomial infection, but in recent years, a noticeable spike in community-acquired cases has occurred. C. diff infection (CDI) testing is often complicated, as various testing options with differing sensitivity and specificity for active infection are available. Also, recent guideline changes have altered the recommended treatment of infection. This article discusses recent changes to both the diagnosis and management of CDI and how they can be applied to everyday NP practice.

Predicting Clostridioides difficile infection outcomes with explainable machine learning

BACKGROUND

Clostridioides difficile infection results in life-threatening short-term outcomes and the potential for subsequent recurrent infection. Predicting these outcomes at diagnosis, when important clinical decisions need to be made, has proven to be a difficult task.

METHODS

52 clinical features from existing models or the literature were collected retrospectively within ±48 h of diagnosis among 1660 inpatient infections. A modified desirability of outcome ranking (DOOR) was designed to encompass clinically-important severe events attributable to the acute infection (intensive care transfer due to sepsis, shock, colectomy/ileostomy, mortality) and/or 60-day recurrence. A deep neural network was constructed and interpreted using SHapley Additive exPlanations (SHAP). High-importance features were used to train a reduced, shallow network and performance was compared to existing conventional models (7 severity, 7 recurrence; after summing DOOR probabilities to align with conventional binary outputs) using area under the ROC curve (AUROC) and DeLong tests.

FINDINGS

The full (52-feature) model achieved an out-of-sample AUROC 0.823 for severity and 0.678 for recurrence. SHAP identified 13 unique, highly-important features (age, hypotension, initial treatment, onset, PCR cycle threshold, number of prior episodes, antibiotic exposure, fever, hypotension, pressors, leukocytosis, creatinine, lactate) that were used to train a reduced model, which performed similarly to the full model (severity AUROC difference P = 0.130; recurrence P = 0.426) and significantly better than the top severity model (reduced model predicting severity 0.837, ATLAS 0.749; P = 0.001). The reduced model also outperformed the top recurrence model, but this was not statistically-significant (reduced model recurrence AUROC 0.653, IDSA Recurrence Risk Criteria 0.595; P = 0.196). The final, reduced model was deployed as a web application with real-time SHAP explanations.

INTERPRETATION

Our final model outperformed existing severity and recurrence models; however, it requires external validation. A DOOR output allows specific clinical questions to be asked with explainable predictions that can be feasibly implemented with limited computing resources.

FUNDING

National Institutes of Health-Institute of Allergy and Infectious Diseases.

Monoclonal antibody-mediated neutralization of Clostridioides difficile toxin does not diminish induction of the protective innate immune response to infection

Clostridioides difficile infection causes pathology that ranges in severity from diarrhea to pseudomembranous colitis. Toxin A and Toxin B are the two primary virulence factors secreted by C. difficile that drive disease severity. The toxins damage intestinal epithelial cells leading to a loss of barrier integrity and induction of a proinflammatory host response. Monoclonal antibodies (mAbs) that neutralize Toxin A and Toxin B, actoxumab and bezlotoxumab, respectively, significantly reduce disease severity in a murine model of C. difficile infection. However, the impact of toxin neutralization on the induction and quality of the innate immune response following infection is unknown. The goal of this study was to define the quality of the host innate immune response in the context of anti-toxin mAbs therapy. At day 2 post-infection, C. difficile-infected, mAbs-treated mice had significantly less disease compared to isotype-treated mice despite remaining colonized with C. difficile. C. difficile-infected mAbs-treated mice still exhibited marked neutrophil infiltration and induction of a subset of proinflammatory cytokines within the intestinal lamina propria following infection that is comparable to isotype-treated mice. Furthermore, both mAbs and isotype-treated mice had an increase in IL-22-producing ILCs in the intestine following infection. MAbs-treated mice exhibited increased infiltration of eosinophils in the intestinal lamina propria, which has been previously reported to promote a protective host response following C. difficile infection. These findings show that activation of host protective mechanisms remain intact in the context of monoclonal antibody-mediated toxin neutralization.

Risk of Clostridioides difficile infection following different antibiotics: insights from multi-source medical data

OBJECTIVE

Antibiotic utilization stands as the strongest modifiable determinant for Clostridioides difficile infection (CDI). However, previous studies have relied on aggregated antibiotic categories, leaving prescribers without detailed comparative risk information for individual antibiotics. The objective of this study was to estimate the risk of CDI comprehensively across specific antibiotics.

METHODS

Two methodologies were integrated to access and rank the risk of CDI associated with individual antibiotics or classes. Initially, a network comparison was conducted by analysing data from randomized controlled trials (RCTs). Subsequently, a real-world disproportionality analysis using the Food and Drug Adverse Event Reporting System (FAERS) database complemented and enriched the findings from RCTs.

RESULTS

The network comparison, encompassing 61 RCTs with 25,931 patients, revealed that exposure to cefepime [odds ratio (OR) 2.56, 95% confidence interval (CI) 1.20-5.44; P=0.02] and imipenem/cilastatin (OR 3.86, 95% CI 1.61-9.29; P=0.003) exhibited higher frequencies of CDI compared with piperacillin/tazobactam. No significant differences were observed between the carbapenems, albeit a trend indicating higher incidence of CDI with imipenem/cilastatin compared with meropenem (OR 3.89, 95% CI 0.94-16.09). In the FAERS disproportionality analysis, nearly all antibiotics displayed associations with CDI, and CDI risk signals often clustered within the majority of antibiotic classes. Among these, lincomycin demonstrated the strongest association (OR 112.17, 95% CI 51.68-243.43). Additionally, oral third-generation cephalosporins tended to exhibit higher CDI risk signals than other antibiotics.

CONCLUSIONS

The findings unveiled substantial diversity in the risk of CDI, both within and between antibiotic classes, providing valuable guidance for clinicians in antibiotic prescription decisions and for initiatives aimed at antibiotic stewardship.

Vonoprazan-associated Clostridioides difficile infection: an analysis of the Japanese Adverse Drug Event Report and the FDA Adverse Event Reporting System

Background

Prolonged or excessive use of acid suppressants may increase the risk of Clostridioides difficile infection (CDI) by altering the intestinal microecosystem. Vonoprazan, a novel potassium-competitive acid blocker, exhibits a faster and more sustained acid-suppressive effect than proton pump inhibitors (PPIs). Therefore, vonoprazan may have a greater impact on the gut microbiota, potentially resulting in CDI.

Objectives

This study aimed to explore the potential relationship between acid suppressants and CDI by the Japan Adverse Drug Event Report (JADER) and the FDA Adverse Event Reporting System (FAERS) databases.

Design

A retrospective analysis of the JADER and FAERS databases was examined by disproportionality analysis.

Methods

We performed signal detection analyses of CDI induced by vonoprazan and PPIs using the JADER and FAERS databases. The association between acid suppressants and CDI was calculated using the reporting odds ratio (ROR) and corresponding 95% confidence interval (95% CI). When the lower limit of the 95% CI is exceeded by 1, the association is considered statistically significant.

Results

In the JADER database, the ROR (95% CI) for vonoprazan and PPIs based on suspect drug reports was 15.84 (12.23-20.50) and 2.51 (1.92-3.28), respectively. In the FAERS database, the ROR (95% CI) for vonoprazan and PPIs based on primary and secondary suspect drug reports was 11.50 (6.36-20.82) and 1.42 (1.34-1.51), respectively. Subgroup analysis showed that elderly patients aged 60 years and older were more strongly associated with CDI. The ROR (95% CI) for vonoprazan and PPIs in patients aged 60 years and older in the JADER database was 15.35 (11.59-20.33) and 1.65 (1.14-2.39), respectively. Similarly, the ROR (95% CI) for vonoprazan and PPIs in the FAERS database was 12.56 (6.26-25.20) and 1.43 (1.31-1.57), respectively. Excluding the effect of Helicobacter pylori (H. pylori) infection, the use of acid suppressants was still associated with CDI.

Conclusion

While signal detection analysis based on the JADER and FAERS databases could not establish causality, our study demonstrated that both vonoprazan and PPIs were significantly associated with CDI. Vonoprazan showed a stronger association with CDI in both databases.

Mortality Attributable to Clostridioides difficile Infection: The Rising Burden of Disease in European Countries

Background and Objectives: Clostridioides difficile infection is a major public health issue, being among the main causes of mortality due to healthcare-associated diarrhea. This study aimed to assess the trends in mortality attributable to Clostridioides difficile infections in European countries over a period of 30 years. Materials and Methods: A descriptive epidemiological study was conducted, with the application of an ecological study design, to evaluate the trends in mortality due to Clostridioides difficile infection in the Central, Eastern, and Western European sub-regions from 1990 to 2019. The Global Burden of Disease study database was used. Trends were evaluated with the joinpoint regression analysis. Results: In both sexes, about 76% of all deaths attributable to Clostridioides difficile infections were recorded in the Western European sub-region in 2019. The age-standardized rates of the burden of Clostridioides difficile infection in 2019 were the highest in the Central European sub-region, followed by the Western European sub-region, while the lowest rates were observed in the Eastern European sub-region. A significantly increasing trend in mortality attributable to Clostridioides difficile infection from 1990 to 2019 was recorded both in males (by +2.1% per year) and females (by +2.8% per year). The burden of Clostridioides difficile infection showed increasing trends in most of the European countries, significantly correlating with the country's development, according to the Human Development Index. Conclusions: The rising burden of Clostridioides difficile infection in European countries in the last few decades suggests a need for improving public health measures, with a focus both on the hospital setting and community.

Clostridioides difficile superoxide reductase mitigates oxygen sensitivity

Clostridioides difficile causes a serious diarrheal disease and is a common healthcare-associated bacterial pathogen. Although it has a major impact on human health, the mechanistic details of C. difficile intestinal colonization remain undefined. C. difficile is highly sensitive to oxygen and requires anaerobic conditions for in vitro growth. However, the mammalian gut is not devoid of oxygen, and C. difficile tolerates moderate oxidative stress in vivo. The C. difficile genome encodes several antioxidant proteins, including a predicted superoxide reductase (SOR) that is upregulated upon exposure to antimicrobial peptides. The goal of this study was to establish SOR enzymatic activity and assess its role in protecting C. difficile against oxygen exposure. Insertional inactivation of sor rendered C. difficile more sensitive to superoxide, indicating that SOR contributes to antioxidant defense. Heterologous C. difficile sor expression in Escherichia coli conferred protection against superoxide-dependent growth inhibition, and the corresponding cell lysates showed superoxide scavenging activity. Finally, a C. difficile SOR mutant exhibited global proteome changes under oxygen stress when compared to the parent strain. Collectively, our data establish the enzymatic activity of C. difficile SOR, confirm its role in protection against oxidative stress, and demonstrate SOR's broader impacts on the C. difficile vegetative cell proteome.IMPORTANCEClostridioides difficile is an important pathogen strongly associated with healthcare settings and capable of causing severe diarrheal disease. While considered a strict anaerobe in vitro, C. difficile has been shown to tolerate low levels of oxygen in the mammalian host. Among other well-characterized antioxidant proteins, the C. difficile genome encodes a predicted superoxide reductase (SOR), an understudied component of antioxidant defense in pathogens. The significance of the research reported herein is the characterization of SOR's enzymatic activity, including confirmation of its role in protecting C. difficile against oxidative stress. This furthers our understanding of C. difficile pathogenesis and presents a potential new avenue for targeted therapies.

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.

Clostridioides difficile colonization is not mediated by bile salts and requires Stickland fermentation of proline in an in vitro model of infection

Treatment with antibiotics is a major risk factor for Clostridioides difficile infection, likely due to depletion of the gastrointestinal microbiota. Two microbiota-mediated mechanisms thought to limit C. difficile colonization include conversion of conjugated primary bile salts into secondary bile salts toxic to C. difficile growth, and competition between the microbiota and C. difficile for limiting nutrients. Using a continuous flow model of the distal colon, we investigated how treatment with six clinically-used antibiotics influenced susceptibility to C. difficile infection in 12 different microbial communities cultivated from healthy individuals. Antibiotic treatment reduced microbial richness; disruption varied by antibiotic class and microbiota composition, but did not correlate with C. difficile susceptibility. Antibiotic treatment also disrupted microbial bile salt metabolism, increasing levels of the primary bile salt, cholate, and decreasing levels of the secondary bile salt, deoxycholate. However, decreased levels of deoxycholate did not correlate with increased C. difficile susceptibility. Further, bile salts were not required to inhibit C. difficile colonization. We tested whether amino acid fermentation contributed to persistence of C. difficile in antibiotic-treated communities. C. difficile mutants unable to use proline as an electron acceptor in Stickland fermentation due to disruption of proline reductase (Δ prdB ) had significantly lower levels of colonization than wild-type strains in four of six antibiotic-treated communities tested. This data provides further support for the importance of bile salt-independent mechanisms in regulating colonization of C. difficile .

IMPORTANCE

C. difficile is one of the leading causes of hospital-acquired infections and antibiotic-associated diarrhea. Several potential mechanisms through which the microbiota can limit C. difficile infection have been identified and are potential targets for new therapeutics. However, it is unclear which mechanisms of C. difficile inhibition represent the best targets for development of new therapeutics. These studies demonstrate that in a complex in vitro model of C. difficile infection, colonization resistance is independent of microbial bile salt metabolism. Instead, the ability of C. difficile to colonize is dependent upon its ability to metabolize proline, although proline-dependent colonization is context-dependent and is not observed in all disrupted communities. Altogether, these studies support the need for further work to understand how bile-independent mechanisms regulate C. difficile colonization.

Clinical characteristics of community-onset Clostridioides difficile infections at a tertiary hospital in mainland China: A fourteen-year (2010-2023) retrospective study

BACKGROUND

Clostridioides difficile infection (CDI) is an increasingly common disease in healthcare facilities and community settings. However, there are limited reports of community-onset CDI (CO-CDI) in China.

METHODS

We collected diarrheal stool samples from 3885 patients who went to outpatient department or emergency department in a tertiary hospital in China during 2010-2023, analyzed the correlation between patients' basic information and the detection rate of CDI. Besides, all stool samples from 3885 outpatients included were tested by culturing. Moreover, we randomly selected 89 patients' stools during the 14 years and isolated 126 C. difficile strains from them. The presence of toxin genes (tcdA, tcdB, cdtA, and cdtB) were confirmed by PCR. Toxigenic strains were typed using multilocus sequence typing (MLST). Susceptibility to 9 antimicrobials was evaluated using the E-test.

RESULTS

528 of 3885 patients (13.6 %) with diarrhea were finally diagnosed as CDI. The median age of patients included was 51 years (6 months-95 years), while the median of patients with CDI was older than patients with negative results [55.5 years (6 months-93 years) vs. 50 years (9 months -95 years), p < 0.001]. In winter, patients with diarrhea might be more likely to have CDI. The detection rate of CDI of patients in emergency department was much higher than those in other outpatients (20.7 % vs. 12.4 %, p < 0.001), and did differ from each outpatient departments (p < 0.05). There were 95 isolated strains detected as toxigenic C. difficile. Among these strains, 82 (86.3 %) had the tcdA and tcdB genes (A+B+) and 5 of these 82 strains were positive for the binary toxin genes (cdtA and cdtB) (A+B+CDT+). There were 15 different sequence types (STs) by multilocus sequence typing (MLST), while the most ST was ST-54 (23.2 %). ST types composition was relatively stable over the time span of this study. Some strains had high resistance to ciprofloxacin, clindamycin, and erythromycin. Twenty-three isolates (24.2 %) were multidrug-resistant.

CONCLUSIONS

Outpatients with CDI were common among patients having diarrhea during this period in our hospital. Elderly patients and patients went to emergency department may be susceptible to CDI. Based on MLST, the result revealed that the C. difficile isolates had high genetic diversity and maintained stability in this period. All isolates were susceptible to metronidazole and vancomycin, and nearly one quarter of all isolates had multidrug resistance.

Fighting against Clostridioides difficile infection: Current medications

Clostridioides difficile (formerly Clostridium difficile) has been regarded as an 'urgent threat' and a significant global health problem, as life-threatening diarrhoea and refractory recurrence are common in patients with C. difficile infection (CDI). Unfortunately, the available anti-CDI drugs are limited. Recent guidelines recommend fidaxomicin and vancomycin as first-line drugs to treat CDI, bezlotoxumab to prevent recurrence, and faecal microbiota transplantation for rescue treatment. Currently, researchers are investigating therapeutic antibacterial drugs (e.g. teicoplanin, ridinilazole, ibezapolstat, surotomycin, cadazolid, and LFF571), preventive medications against recurrence (e.g. Rebyota, Vowst, VP20621, VE303, RBX7455, and MET-2), primary prevention strategies (e.g. vaccine, ribaxamase, and DAV132) and other anti-CDI medications in the preclinical stage (e.g. Raja 42, Myxopyronin B, and bacteriophage). This narrative review summarises current medications, including newly marketed drugs and products in development against CDI, to help clinicians treat CDI appropriately and to call for more research on innovation.

[Need for improvement in the care of patients with Clostridioides difficile infections (CDI) - expert opinion in international comparison]

INTRODUCTION

Clostridioides difficile infection (CDI), as a nosocomial disease, is associated with high morbidity and mortality. Even though the incidence of CDI has been declining in Germany in recent years, the individual infection may pose a medical challenge despite therapeutic advances. The aim here is to clarify which gaps practitioners consider to be particularly serious in care and in the existing evidence base.

METHODS

In a moderated workshop of German CDI experts the topics considered as relevant were identified. A survey already conducted in five other countries (Australia, France, Great Britain, Canada, and Italy) was adapted and processed by 27 practitioners. During the evaluation, the topics perceived as particularly important were identified, the statements of the specialist groups were compared and changes in opinion were considered.

RESULTS

27 fully completed questionnaires were evaluated. The need for improvement was primarily seen in the prevention of CDI recurrences (74.1%) and the treatment of recurrences (55.6%). Evidence deficits were noted in the treatment of recurrences (55.6%) and identification of risk factors for recurrences (48.1%). Improving care via fecal microbiota transfer (FMT) was named by 70.4%. For guidelines, more clarity (48.1%) and more regular updates (40.7%) were desired. For patients, better education on appropriate antibiotic use (52.0%) and choice of FMT were desired (48.1%).

SUMMARY

The German expert view and the international assessment is similar, when asked about the need for improvement in care and evidence gaps in the treatment of patients with CDI: The focus is on prevention and therapy of recurrent CDI. The problem of access to FMT is a German peculiarity that seems to need improvement.

RelQ-mediated alarmone signalling regulates growth, stress-induced biofilm formation and spore accumulation in Clostridioides difficile

The bacterial stringent response (SR) is a conserved transcriptional reprogramming pathway mediated by the nucleotide signalling alarmones, (pp)pGpp. The SR has been implicated in antibiotic survival in Clostridioides difficile, a biofilm- and spore-forming pathogen that causes resilient, highly recurrent C. difficile infections. The role of the SR in other processes and the effectors by which it regulates C. difficile physiology are unknown. C. difficile RelQ is a clostridial alarmone synthetase. Deletion of relQ dysregulates C. difficile growth in unstressed conditions, affects susceptibility to antibiotic and oxidative stressors and drastically reduces biofilm formation. While wild-type C. difficile displays increased biofilm formation in the presence of sublethal stress, the ΔrelQ strain cannot upregulate biofilm production in response to stress. Deletion of relQ slows spore accumulation in planktonic cultures but accelerates it in biofilms. This work establishes biofilm formation and spore accumulation as alarmone-mediated processes in C. difficile and reveals the importance of RelQ in stress-induced biofilm regulation.

The impact of Clostridioides difficile infection on outcomes among kidney transplant recipients

BACKGROUND

Clostridioides difficile infection (CDI) is a significant cause of morbidity and mortality among hospitalized patients, particularly those who are immunosuppressed. We aim to assess the outcomes of CDI among kidney transplant (KT) recipients.

METHODS

Nationwide Inpatient Sample from 2016 to 2020 was used to identify patients with KT and stratify based on the presence of CDI. Data were collected regarding demographics and comorbidities. Outcomes included in-hospital mortality, acute kidney injury, intensive care unit admission, transplant rejection, transplant failure, length of stay, and total hospitalization charges. The relationships between variables of interest and outcomes were analyzed using multivariate regression.

RESULTS

A total of 557,635 KT recipients were included. CDI prevalence was 2.4%. The majority of patients in the CDI group were age >65 (43.6%), female (51%), White (55.3%), and had Medicare insurance (74.9%). On multivariate regression analysis, CDI was associated with increased odds of acute kidney injury (aOR 2.06, p < 0.001), intensive care unit admission (aOR 2.47, p < 0.001), and mortality (aOR 1.90, p < 0.001). CDI was also associated with longer length of stay (9.35 days vs 5.42 days, p < 0.001) and higher total hospitalization charges ($110,063 vs $100,006, p < 0.001). There was no difference in transplant rejection, complication, failure, or infection among KT recipients with CDI and those without.

CONCLUSIONS

We found that CDI was associated with worse outcomes and higher costs. KT patients should be monitored closely for signs of CDI in order to initiate appropriate management.

Comparative Efficacy of Fecal Microbiota Transplantation in Treating Refractory or Recurrent Clostridioides difficile Infection among Patients with and without Inflammatory Bowel Disease: A Retrospective Cohort Study

Clostridioides difficile infection (CDI) worsens inflammatory bowel disease (IBD) prognosis. While fecal microbiota transplantation (FMT) is effective for refractory or recurrent CDI (rrCDI), comparative success rates between IBD and non-IBD patients are scarce. This study addresses this gap. A retrospective cohort study was conducted at Chang Gung Memorial Hospital from April 2019 to October 2023. Patients receiving FMT for rrCDI were categorized into IBD and non-IBD groups. Baseline characteristics and outcomes were compared at one month and one year, with successful FMT defined as the resolution of diarrhea without CDI recurrence. The study included 88 patients: 30 with IBD and 58 without IBD. The IBD group was younger, with fewer comorbidities. Success rates at one month were similar between groups (IBD: 80.0% vs. non-IBD: 78.9%, p = 0.908), as were negative toxin tests (IBD: 83.3% vs. non-IBD: 63.8%, p = 0.174). One-year success rates (IBD: 70.0% vs. non-IBD: 67.6%, p = 0.857) and eradication rates (IBD: 94.4% vs. non-IBD: 73.9%, p = 0.112) were also similar. Poor bowel preparation predicted FMT failure at one month (OR = 0.23, p = 0.019). No safety issues were reported. FMT is a safe, effective treatment for rrCDI, demonstrating similar success rates in patients with and without IBD.

Rapid, Point-of-Care Microwave Lysis and Electrochemical Detection of Clostridioides difficile Directly from Stool Samples

The rapid detection of the spore form of Clostridioides difficile has remained a challenge for clinicians. To address this, we have developed a novel, precise, microwave-enhanced approach for near-spontaneous release of DNA from C. difficile spores via a bespoke microwave lysis platform. C. difficile spores were microwave-irradiated for 5 s in a pulsed microwave electric field at 2.45 GHz to lyse the spore and bacteria in each sample, which was then added to a screen-printed electrode and electrochemical DNA biosensor assay system to identify presence of the pathogen's two toxin genes. The microwave lysis method released both single-stranded and double-stranded genome DNA from the bacterium at quantifiable concentrations between 0.02 μg/mL to 250 μg/mL allowing for subsequent downstream detection in the biosensor. The electrochemical bench-top system comprises of oligonucleotide probes specific to conserved regions within tcdA and tcdB toxin genes of C. difficile and was able to detect 800 spores of C. difficile within 300 µL of unprocessed human stool samples in under 10 min. These results demonstrate the feasibility of using a solid-state power generated, pulsed microwave electric field to lyse and release DNA from human stool infected with C. difficile spores. This rapid microwave lysis method enhanced the rapidity of subsequent electrochemical detection in the development of a rapid point-of-care biosensor platform for C. difficile.

A Randomized, Double-Blind, Phase 3 Safety and Efficacy Study of Ridinilazole Versus Vancomycin for Treatment of Clostridioides difficile Infection: Clinical Outcomes With Microbiome and Metabolome Correlates of Response

BACKGROUND

Exposure to antibiotics predisposes to dysbiosis and Clostridioides difficile infection (CDI) that can be severe, recurrent (rCDI), and life-threatening. Nonselective drugs that treat CDI and perpetuate dysbiosis are associated with rCDI, in part due to loss of microbiome-derived secondary bile acid (SBA) production. Ridinilazole is a highly selective drug designed to treat CDI and prevent rCDI.

METHODS

In this phase 3 superiority trial, adults with CDI, confirmed with a stool toxin test, were randomized to receive 10 days of ridinilazole (200 mg twice daily) or vancomycin (125 mg 4 times daily). The primary endpoint was sustained clinical response (SCR), defined as clinical response and no rCDI through 30 days after end of treatment. Secondary endpoints included rCDI and change in relative abundance of SBAs.

RESULTS

Ridinilazole and vancomycin achieved an SCR rate of 73% versus 70.7%, respectively, a treatment difference of 2.2% (95% CI: -4.2%, 8.6%). Ridinilazole resulted in a 53% reduction in recurrence compared with vancomycin (8.1% vs 17.3%; 95% CI: -14.1%, -4.5%; P = .0002). Subgroup analyses revealed consistent ridinilazole benefit for reduction in rCDI across subgroups. Ridinilazole preserved microbiota diversity, increased SBAs, and did not increase the resistome. Conversely, vancomycin worsened CDI-associated dysbiosis, decreased SBAs, increased Proteobacteria abundance (∼3.5-fold), and increased the resistome.

CONCLUSIONS

Although ridinilazole did not meet superiority in SCR, ridinilazole greatly reduced rCDI and preserved microbiome diversity and SBAs compared with vancomycin. These findings suggest that treatment of CDI with ridinilazole results in an earlier recovery of gut microbiome health. Clinical Trials Registration.Ri-CoDIFy 1 and 2: NCT03595553 and NCT03595566.

Clostridioides difficile infection: history, epidemiology, risk factors, prevention, clinical manifestations, treatment, and future options

SUMMARYClostridioides difficile infection (CDI) is one of the major issues in nosocomial infections. This bacterium is constantly evolving and poses complex challenges for clinicians, often encountered in real-life scenarios. In the face of CDI, we are increasingly equipped with new therapeutic strategies, such as monoclonal antibodies and live biotherapeutic products, which need to be thoroughly understood to fully harness their benefits. Moreover, interesting options are currently under study for the future, including bacteriophages, vaccines, and antibiotic inhibitors. Surveillance and prevention strategies continue to play a pivotal role in limiting the spread of the infection. In this review, we aim to provide the reader with a comprehensive overview of epidemiological aspects, predisposing factors, clinical manifestations, diagnostic tools, and current and future prophylactic and therapeutic options for C. difficile infection.

Discovery and Structure-Activity Relationship of Cadazolid: A First-In-Class Quinoxolidinone Antibiotic for the Treatment of Clostridioides difficile Infection

Clostridioides difficile (C. difficile) is one of the leading causes of healthcare-associated infections worldwide. The increasing incidence of strains resistant to currently available therapies highlights the need for alternative treatment options with a novel mode of action. Oxazolidinones that are connected to a quinolone moiety with a pyrrolidine linker, such as compound 1, are reported to exhibit potent broadspectrum antibacterial activity. In an effort to optimize this class of compounds for the treatment of C. difficile infection (CDI), we have identified cadazolid (9), a first-in-class quinoxolidinone antibiotic, which is a potent inhibitor of C. difficile protein synthesis. In order to achieve narrow-spectrum coverage of clinically most relevant strains without affecting the gut microbiota, an emphasis was placed on abolishing activity against commensals of the intestinal microbiome while retaining good coverage of pathogenic C. difficile, including hypervirulent and epidemic strains.

The changing epidemiology of Clostridioides difficile infection and the NAP1/027 strain in two Québec hospitals: a 17-year time-series study

Objective

To describe the epidemiology of healthcare-associated Clostridioides difficile infection (HA-CDI) in two Québec hospitals in Canada following the 2003 epidemic and to evaluate the impact of antibiotic stewardship on the incidence of HA-CDI and the NAP1/027 strain.

Design

Time-series analysis.

Setting

Two Canadian tertiary care hospitals based in Montréal, Québec.

Patients

Patients with a positive assay for toxigenic C. difficile were identified through infection control surveillance. All cases of HA-CDI, defined as symptoms occurring after 72 hours of hospital admission or within 4 weeks of hospitalization, were included.

Methods

The incidence of HA-CDI and antibiotic utilization from 2003 to 2020 were analyzed with available C. difficile isolates. The impact of antibiotic utilization on HA-CDI incidence was estimated by a dynamic regression time-series model. Antibiotic utilization and the proportion of NAP1/027 strains were compared biannually for available isolates from 2010 to 2020.

Results

The incidence of HA-CDI decreased between 2003 and 2020 at both hospitals from 26.5 cases per 10,000 patient-days in 2003 to 4.9 cases per 10,000 patient-days in 2020 respectively. Over the study period, there were an increase in the utilization of third-generation cephalosporins and a decrease in usage of fluoroquinolones and clindamycin. A decrease in fluoroquinolone utilization was associated with a significant decrease in HA-CDI incidence as well as decrease in the NAP1/027 strain by approximately 80% in both hospitals.

Conclusions

Decreased utilization of fluoroquinolones in two Québec hospitals was associated with a decrease in the incidence of HA-CDI and a genotype shift from NAP1/027 to non-NAP1/027 strains.

Comparison of rectal swabs and fecal samples for the detection of Clostridioides difficile infections with a new in-house PCR assay

The detection of Clostridioides difficile infections (CDI) relies on testing the stool of patients by toxin antigen detection or PCR methods. Although PCR and antigenic methods have significantly reduced the time to results, delays in stool collection can significantly add to the turnaround time. The use of rectal swabs to detect C. difficile could considerably reduce the time to diagnosis of CDI. We developed a new rapid PCR assay for the detection of C. difficile and evaluated this PCR assay on both stool and rectal swab specimens. We recruited a total of 623 patients suspected of C. difficile infection. Stool samples and rectal swabs were collected from each patient and tested by our PCR assay. Stool samples were also tested by the cell cytotoxicity neutralization assay (CCNA) as a reference. The PCR assay detected C. difficile in 60 stool specimens and 61 rectal swabs for the 64 patients whose stool samples were positive for C. difficile by CCNA. The PCR assay detected an additional 35 and 36 stool and rectal swab specimens positive for C. difficile, respectively, for sensitivity with stools and rectal swabs of 93.8% and 95.3%, specificity of 93.7% and 93.6%, positive predictive values of 63.2% and 62.9%, and negative predictive values of 99.2% and 99.4%. Detection of C. difficile using PCR on stools or rectal swabs yielded reliable and similar results. The use of PCR tests on rectal swabs could reduce turnaround time for CDI detection, thus improving CDI management and control of C. difficile transmission.

IMPORTANCE

Clostridioides difficile infection (CDI) is the leading cause of healthcare-associated diarrhea, resulting in high morbidity, mortality, and economic burden. In clinical laboratories, CDI testing is currently performed on stool samples collected from patients with diarrhea. However, the diagnosis of CDI can be delayed by the time required to collect stool samples. Barriers to sample collection could be overcome by using a rectal swab instead of a stool sample. Our study showed that CDI can be identified rapidly and reliably by a new PCR assay developed in our laboratory on both stool and rectal swab specimens. The use of PCR tests on rectal swabs could reduce the time for the detection of CDI and improve the management of this infection. It should also provide a useful alternative for infection-control practitioners to better control the spread of C. difficile.

Novel target and PCR assay for identification of hypervirulent ST1 (BI/NAP1/027) Clostridioides difficile and detection of toxigenic C. Difficile

BACKGROUND AND AIMS

The incidence of Clostridioides difficile infection and the prevalence of hypervirulent ST1 (BI/NAP1/027)strain are increasing, especially in developing countries. We aimed to develop a new PCR assay for the identification of hypervirulent ST1 strains and toxigenic C. difficile in stool samples.

MATERIALS AND METHODS

We established a quadruplex TaqMan real-time PCR (pilW_4-plex PCR) assay targeting the pilW, a ST1-specific type Ⅳ minor pilin gene, and three C. difficile genes including cdtB, tcdB, and hsp. The sensitivity and specificity of the assay was tested using 403C. difficile isolates and 180 unformed stool sample. The results were compared with anaerobic culture-based conventional PCR method and MLST.

RESULTS

The pilW_4-plex PCR identified toxigenic C. difficile in 333 (82.6%, 333/403) isolates with 100% sensitivity and specificity, and in 78 (43.3%, 78/180) stool samples with the sensitivity and specificity of 94.7% and 93.3%, respectively. Hypervirulent ST1 were detected in 21 strains and nine stool samples by the pilW_4-plex PCR. The pilW_4-plex PCR assay has no cross-reaction with non-toxigenic C. difficile or other bacteria.

CONCLUSION

The pilW_4-plex PCR assay is an accurate and rapid method with high sensitivity and specificity for identification of ST1 and detection of toxigenic C. difficile in stool.

The Impact of Gastroesophageal Disease on Clostridium difficile Infection Hospitalization: A Nationwide Analysis From the United States

Background Enterocolitis due to Clostridium difficile infection (CDI) is one of the most common infectious causes of healthcare-associated diarrhea and a significant cause of morbidity and mortality among hospitalized patients. Gastroesophageal reflux disease (GERD) is notable for its high prevalence, variety of clinical presentations, and underrecognized morbidity. It is widely treated with acid suppression, both with over-the-counter and prescription medications. There are no studies evaluating the impact of GERD on CDI hospitalization. In this study, we aimed to analyze the influence of concomitant GERD on patients hospitalized for CDI enterocolitis. Methodology This was a retrospective, observational study where we extracted data from 2016 to 2020 from the National Inpatient Sample database. We included all patients hospitalized with a primary discharge diagnosis of CDI with or without a secondary diagnosis of GERD. We compared the demographics, comorbidities, and in-hospital outcomes between these two groups. Results This study identified 239,603 hospitalizations with a discharge diagnosis of CDI. Of these, 67,000 (28%) had a concurrent diagnosis of GERD. Patients with GERD had a higher prevalence of hypertension (41% vs. 35.5%, p < 0.01), hyperlipidemia (50% vs. 36.5%, p < 0.01), obesity (13.7% vs. 10.5%, p < 0.01), coronary artery disease (24.4% vs. 19.6%, p < 0.01), and chronic kidney disease (20.7% vs. 19.2%, p < 0.01). Notably, inpatient mortality was lower in CDI hospitalizations with GERD (0.66% vs. 1.46%, p < 0.01). The total hospital charge was reduced in the CDI with GERD group in comparison to the CDI without GERD group (39,599 vs. 43,589, p < 0.01). The length of hospital stay was similar between the two groups (5.3 vs. 5.4 days, p = 0.07). Regarding complications, CDI hospitalizations with GERD demonstrated lower rates of hypovolemic shock (0.5% vs. 0.73%, p = 0.06), septic shock (0.6% vs. 1.05%, p < 0.01), acute kidney injury (1.48% vs. 2.04%, p < 0.01), intestinal perforation (0.008% vs. 0.16%, p = 0.03), and lactic acidosis (0.008% vs. 0.16%, p = 0.03). Conversely, CDI patients with GERD had a higher rate of ileus (2.66% vs. 2.16%, p < 0.01). Conclusions Patients with CDI and concurrent GERD exhibited favorable in-hospital outcomes in terms of complication rates, mortality, and total hospital charges. Further research is required to comprehensively explore and validate these findings.

Review article: The epidemiology and management of Clostridioides difficile infection-A clinical update

BACKGROUND

Clostridioides difficile is the most common cause of healthcare-associated infection, and severe cases can result in significant complications. While anti-microbial therapy is central to infection management, adjunctive therapies may be utilised as preventative strategies.

AIM

This article aims to review updates in the epidemiology, diagnosis, and management, including treatment and prevention, of C. difficile infections.

METHODS

A narrative review was performed to evaluate the current literature between 1986 and 2023.

RESULTS

The incidence of C. difficile infection remains significantly high in both hospital and community settings, though with an overall decline in recent years and similar surveillance estimates globally. Vancomycin and fidaxomicin remain the first line antibiotics for treatment of non-severe C. difficile infection, though due to lower recurrence rates, infectious disease society guidelines now favour use of fidaxomicin. Faecal microbiota transplantation should still be considered to prevent recurrent C. difficile infection. However, in the past year the field has had a significant advancement with the approval of the first two live biotherapeutic products-faecal microbiota spores-live brpk, an oral capsule preparation, and faecal microbiota live-jslm-both indicated for the prevention of recurrent C. difficile infection, with additional therapies on the horizon.

CONCLUSION

Although the prevalence of C. difficile infection remains high, there have been significant advances in the development of novel therapeutics and preventative measures following changes in recent practice guidelines, and will continue to evolve in the future.

Machine Learning-Based Prediction Models for Clostridioides difficile Infection: A Systematic Review

INTRODUCTION

Despite research efforts, predicting Clostridioides difficile incidence and its outcomes remains challenging. The aim of this systematic review was to evaluate the performance of machine learning (ML) models in predicting C. difficile infection (CDI) incidence and complications using clinical data from electronic health records.

METHODS

We conducted a comprehensive search of databases (OVID, Embase, MEDLINE ALL, Web of Science, and Scopus) from inception up to September 2023. Studies employing ML techniques for predicting CDI or its complications were included. The primary outcome was the type and performance of ML models assessed using the area under the receiver operating characteristic curve.

RESULTS

Twelve retrospective studies that evaluated CDI incidence and/or outcomes were included. The most commonly used ML models were random forest and gradient boosting. The area under the receiver operating characteristic curve ranged from 0.60 to 0.81 for predicting CDI incidence, 0.59 to 0.80 for recurrence, and 0.64 to 0.88 for predicting complications. Advanced ML models demonstrated similar performance to traditional logistic regression. However, there was notable heterogeneity in defining CDI and the different outcomes, including incidence, recurrence, and complications, and a lack of external validation in most studies.

DISCUSSION

ML models show promise in predicting CDI incidence and outcomes. However, the observed heterogeneity in CDI definitions and the lack of real-world validation highlight challenges in clinical implementation. Future research should focus on external validation and the use of standardized definitions across studies.

Understanding host immune responses in Clostridioides difficile infection: Implications for pathogenesis and immunotherapy

Clostridioides difficile (C. difficile) is the predominant causative agent of nosocomial diarrhea worldwide. Infection with C. difficile occurs due to the secretion of large glycosylating toxin proteins, which can lead to toxic megacolon or mortality in susceptible hosts. A critical aspect of C. difficile's biology is its ability to persist asymptomatically within the human host. Individuals harboring asymptomatic colonization or experiencing a single episode of C. difficile infection (CDI) without recurrence exhibit heightened immune responses compared to symptomatic counterparts. The significance of these immune responses cannot be overstated, as they play critical roles in the development, progression, prognosis, and outcomes of CDI. Nonetheless, our current comprehension of the immune responses implicated in CDI remains limited. Therefore, further investigation is imperative to elucidate their underlying mechanisms. This review explores recent advancements in comprehending CDI pathogenesis and how the host immune system response influences disease progression and severity, aiming to enhance our capacity to develop immunotherapy-based treatments for CDI.

Rise to the Challenge: Master the Management of Clostridioides difficile Infection

Clostridioides difficile infection (CDI) is a significant public health challenge in the developed world. Although previously CDI was primarily a health care-acquired infection, there are now rising numbers of community-acquired cases in patients without traditional risk factors, such as antibiotic exposure. The landscape for the treatment of CDI has changed significantly during the past decade, including newer diagnostic tests, novel antibiotic regimens, and strategies for microbiome restoration in the form of traditional fecal microbiota transplant and approved live biotherapeutics in an effort to address the underlying pathophysiologic process of gut microbial dysbiosis. We present a concise review for clinicians on the diagnosis and management of both primary and recurrent CDI.

Clostridioides difficile Colitis

Clostridioides difficile colitis is an important source of hospital-acquired diarrhea associated with antibiotic use. Symptoms are profuse watery diarrhea, typically following a course of antibiotics; however, some cases of fulminant disease may manifest with shock, ileus, or megacolon. Nonfulminant colitis is treated with oral fidaxomicin. C difficile colitis has a high potential for recurrence, and recurrent episodes are also treated with fidaxomicin. Bezlotoxumab is another medication that may be used in populations at high risk for further recurrence. Fulminant disease is treated with maximal medical therapy and early surgical consultation. Antibiotic stewardship is critical to preventing C difficile colitis.

Molecular Epidemiology of Clostridioides difficile Colonization in Families With Infants

Background

Community-associated Clostridioides difficile infection is a major public health hazard to adults and older children. Infants frequently excrete toxigenic C difficile asymptomatically in their stool, but their importance as a community reservoir of C difficile is uncertain.

Methods

Families of healthy infants were recruited at the baby's 4-month well child visit and were followed longitudinally until the baby was approximately 9 months old. Babies and mothers submitted stool or rectal swabs every 2 weeks that were cultivated for C difficile; fathers' participation was encouraged but not required. Clostridioides difficile isolates were strain-typed by fluorescent polymerase chain reaction ribotyping and by core genome multilocus sequence typing, and the number of families in whom the same strain was cultivated from >1 family member ("strain sharing") was assessed.

Results

Thirty families were enrolled, including 33 infants (3 sets of twins) and 30 mothers; 19 fathers also participated. Clostridioides difficile was identified in 28 of these 30 families over the course of the study, and strain sharing was identified in 17 of these 28. In 3 families, 2 separate strains were shared. The infant was involved in 17 of 20 instances of strain sharing, and in 13 of these, the baby was identified first, with or without a concomitantly excreting adult. Excretion of shared strains usually was persistent.

Conclusions

Clostridioides difficile strain sharing was frequent in healthy families caring for an infant, increasing the likelihood that asymptomatically excreting babies and their families represent a reservoir of the organism in the community.

Approaching toxigenic Clostridia from a One Health perspective

Spore-forming pathogens have a unique capacity to thrive in diverse environments, and with temporal persistence afforded through their ability to sporulate. Their prevalence in diverse ecosystems requires a One Health approach to identify critical reservoirs and outbreak-associated transmission chains, given their capacity to freely move across soils, waterways, foodstuffs and as commensals or infecting pathogens in human and animal populations. Among anaerobic spore-formers, genomic resources for pathogens including C. botulinum, C. difficile, and C. perfringens enable our capacity to identify common and unique factors that support their persistence in diverse reservoirs and capacity to cause disease. Publicly available genomic resources for spore-forming pathogens at NCBI's Pathogen Detection program aid outbreak investigations and longitudinal monitoring in national and international programs in public health and food safety, as well as for local healthcare systems. These tools also enable research to derive new knowledge regarding disease pathogenesis, and to inform strategies in disease prevention and treatment. As global community resources, the continued sharing of strain genomic data and phenotypes further enhances international resources and means to develop impactful applications. We present examples showing use of these resources in surveillance, including capacity to assess linkages among clinical, environmental, and foodborne reservoirs and to further research investigations into factors promoting their persistence and virulence in different settings.

Impact of infectious diseases consultation for hospitalized patients with Clostridioides difficile infection

Clostridioides difficile infection (CDI) is associated with substantial morbidity and mortality. This study described outcomes associated with mandatory infectious diseases (ID) consultation in hospitalized patients with CDI. ID consultation was associated with increased appropriate concomitant antibiotic use, however longer courses of concomitant antibiotics were administered.