Clostridium difficile infection: review

Erythromycin Stress Upregulates Antiangiogenic Metabolites in the Gut Bacterium Aneurinibacillus aneurinilyticus

The interplay among antibiotics, gut microbiota, and disease pathogenesis remains poorly understood, particularly in the context of rare gut bacteria. This study identifies a novel correlation between erythromycin-induced stress and the production of antiangiogenic metabolites in Aneurinibacillus aneurinilyticus, a human gut bacterium. We report the isolation and structural characterization of aneuristatin (1), a metabolite featuring a unique pyrrolo[1,2-a]pyrazine scaffold, along with seven structurally related metabolites (2-8) from A. aneurinilyticus ATCC 12856T. These metabolites were upregulated via the erythromycin-induced activation of the arnA biosynthetic gene. Aneuristatin (1) enhanced prolyl hydroxylase activity, promoting hypoxia-inducible factor-1α (HIF-1α) degradation and reducing downstream targets, including VEGF and EPO. It also exhibited antioxidant effects by reducing ROS levels under hypoxia. Additionally, it inhibited angiogenesis in HUVECs and zebrafish and effectively reduced inflammation, fibrosis, and angiogenesis in a mouse corneal injury model. Our study establishes a molecular basis for the potential of erythromycin-induced aneuristatin (1) to prevent or treat angiogenesis-related diseases such as cancer.

Targeting SleC and CspB in the Inhibition of Spore Germination in Clostridioides difficile

Clostridioides difficile, a Gram-positive, spore-forming anaerobic bacterium, is a major healthcare threat. Its spores colonize the gut following dysbiosis caused by broad-spectrum antibiotics, remaining dormant until host's bile acid triggers germination into vegetative cells that produce toxins, leading to diarrhea, colitis, and potentially death. Current antibiotics to treat C. difficile infection target vegetative cells but not spore germination, a pivotal step in infection development. This study unveils 1,2,4-oxadiazoles as a novel class of spore germination inhibitors and delineates the structure-activity relationship. Screening of 120 oxadiazoles revealed compound 110 (IC50 = 14 ± 1 μM or 6.3 ± 0.4 μg/mL). Compound 110 targets mature SleC (Kd = 12 ± 1.0 μM) and CspB (Kd = 8.0 ± 1.0 μM) on spores, inhibiting their enzymatic activities, thus preventing spore germination. To our knowledge, compound 110 is the first reported spore germination inhibitor targeting SleC/CspB, offering a promising avenue for C. difficile therapies.

Comparative analysis of gut microbiota-mediated bile acid profiles in Bufo gargarizans and Rana chensinensis tadpoles

Bile acids (BAs) are cholesterol derivatives synthesized by the liver, exhibit variation between different species. Researchers have long appreciated that microbiota play the roles in the biotransformation of BAs. However, relatively few studies have been reported on microbial-mediated production and transformation of BAs in amphibians. Our focus here is principally on difference of intestinal microbial diversity and BAs profiles between two common amphibians, Bufo gargarizans (B. gargarizans) and Rana chensinensis (R. chensinensis) tadpoles, through intestinal targeted BAs metabolomics and fecal metagenomic sequencing. The results demonstrated that B. gargarizans possessed higher levels of total BAs and higher ratio of unconjugated / conjugated BAs. In addition, the relative abundance of microbiota with bile salt hydrolase (BSH) activity in B. gargarizans was significantly higher than that of R. chensinensis, which may facilitate the conversion of conjugated to unconjugated BAs. Meanwhile the higher prevalence of bile-acid-induced (BAI) gene encoding microbiota in R. chensinensis may promote the synthesis of deoxycholic acid (DCA). Furthermore, discrepancies in virulence factors (VFs) and energy metabolism were observed between the two species, which may be linked to differences in the microbiota. This study revealed substantial differences in intestinal microbes and BAs across amphibian species, emphasizing the significant impact of intestinal microbes on BAs metabolism.

Evaluation of a Fluorescence Immunoassay for Detection of Clostridioides difficile Glutamate Dehydrogenase and Toxin Antigens

BACKGROUND

Clostridioides difficile infection (CDI) is a leading cause of nosocomial infections in the United States, causing longer hospital stays, significant morbidity, and increased healthcare costs. Accurate CDI diagnosis is essential for timely treatment and infection control. Laboratory diagnosis of CDI commonly involves the detection of glutamate dehydrogenase (GDH) and/or toxins A and B by immunoassays or the toxin genes by nucleic acid amplification. This study assesses the performance of a new commercial test, the Sofia® 2 C. difficile Fluorescent Immunoassay (Sofia 2; FIA; QuidelOrtho), for detecting C. difficile GDH and toxins.

METHODS

Sofia 2 was compared to enzyme immunoassays (EIAs) C. diff Quik Chek Complete (Techlab Inc.) and Immunocard (Meridian Bioscience) using remnant stool samples from 262 patients with suspected CDI.

RESULTS

Sofia 2 demonstrated high agreement with the EIA methods for GDH (positive percentage agreement (PPA): 100%, negative percentage agreement (NPA): 94%, overall percentage of agreement (OPA): 95%) and toxins (PPA: 100%, NPA: 99%, OPA: 99%) detection. Compared to standard-of-care (SOC) testing including toxin gene PCR with the following toxin antigen test, Sofia 2 demonstrates strong PPA (100%), NPA (98%), positive predictive value (71%), and negative predictive value (100%).

CONCLUSIONS

Sofia 2 C. difficile FIA generates rapid results that are comparable to other commercial immunoassays with a simple workflow, supporting its use for CDI diagnosis in clinical practice.

Against Clostridioides difficile Infection: An Update on Vaccine Development

Clostridioides difficile (C. difficile) is a major pathogen responsible for antibiotic-associated diarrhea, frequently observed in hospital settings. Due to the widespread use of antibiotics, the incidence and severity of C. difficile infection (CDI) are rising across the world. CDI is primarily driven by two homologous protein exotoxins, toxin A (TcdA) and toxin B (TcdB). Other putative virulence factors include binary toxin CDT, surface layer proteins, phosphorylated polysaccharides, and spore coat proteins. These C. difficile virulence factors are potential targets for vaccine development. Although several C. difficile vaccines have entered clinical trials, there is currently no approved vaccine on the market. This review outlines the intoxication mechanism during CDI, emphasizing the potential antigens that can be used for vaccine development. We aim to provide a comprehensive overview of the current status of research and development of C. difficile vaccines.

Evaluation of the Potency of the First Commercial Vaccine for Clostridioides difficile Infection in Piglets and Comparison with the Humoral Response in Rabbits

Clostridioides difficile is an anaerobic bacterium that causes disease in both animals and humans. Despite the known significance of this agent, there are no commercial vaccines available for humans, and only one immunogen is marketed for swine. However, no studies have evaluated this vaccine.

BACKGROUND/OBJECTIVES

Therefore, the aim of this study was to assess the potency of the first commercial vaccine for C. difficile infection in piglets and to compare the humoral response in rabbits and sows.

METHODS

Pregnant sows were divided into two groups: a vaccinated group (n = 12), receiving two doses before farrowing, according to the manufacturer's recommendation, and an unvaccinated control group (n = 6). Blood samples were taken from sows and also from piglets up to two days after birth. In addition, two groups of New Zealand rabbits (Oryctolagus cuniculus) received either a half-dose (G1) or a full-dose (G2) of the vaccine, with a control group receiving sterile saline (0.85%). Rabbits were vaccinated twice, 21 days apart, with blood samples collected before each dose and 14 days after the final dose. A serum neutralization assay in Vero cells was performed to evaluate the titers of neutralizing antibodies.

RESULTS

The vaccine demonstrated immunogenicity by stimulating the production of neutralizing antibodies in both rabbits and sows. Additionally, these antibodies were passively transferred to piglets through colostrum, reaching levels comparable to those found in sows. Furthermore, vaccinated rabbits developed antibody titers that do not significantly differ from those obtained in sows and piglets.

CONCLUSIONS

The tested vaccine can induce a humoral immune response against C. difficile A/B toxins in sows and these antibodies are passively transferred to neonatal piglets through colostrum. Also, the vaccination of rabbits might be a useful alternative for evaluating the potency of vaccines against C. difficile.

The Global Burden of Clostridioides difficile Infections, 2016-2024: A Systematic Review and Meta-Analysis

Background: Clostridioides difficile infection (CDI) is a major cause of healthcare-associated infections globally. Understanding variations in CDI incidence and outcomes across settings, populations, and regions is important for guiding prevention strategies. Aim: The aim of this study was to determine the global epidemiology of CDI to better understand disease burden across settings and geographic regions. Methods: Relevant publications were identified through searches of major databases, including PubMed, Scopus, and Web of Science, published from 1 January 2016 through 24 July 2024. Random effects models were used to pool estimates, and 95% confidence intervals (CIs) were calculated. Results: A total of 59 studies, representing 24 countries across North America, Europe, the Asia-Pacific region, Latin America, and the Middle East, met the inclusion criteria. The incidence of CDI was highest in hospital-onset healthcare facility settings, with 5.31 cases/1000 admissions (95% CI 3.76-7.12) and 5.00 cases/10,000 patient-days (95% CI 3.96-6.15). Long-term care facilities reported 44.24 cases/10,000 patient-days (95% CI 39.57-49.17). Pediatric populations faced a greater risk, with 4.52 cases/1000 admissions (95% CI 0.55-12.17), than adults did at 2.13 (95% CI 1.69-2.61). Recurrence rates were highest for community-acquired CDI at 16.22%. The death rates for the CDI cases tracked for 30 days and of unspecified duration were 8.32% and 16.05%, respectively. Conclusions: This comprehensive review identified healthcare facilities, long-term care, pediatric populations, and North America as disproportionately burdened. This finding provides guidance on priority areas and populations for targeted prevention through antimicrobial stewardship, infection control, and surveillance.

Allosterically switchable network orients β-flap in Clostridioides difficile toxins

Allosteric proteins exhibit a functional response upon ligand binding far from the active site. Clostridioides difficile toxins use allosteric binding by the endogenous cofactor myo-inositol hexakisphosphate to orchestrate self-cleavage from within the target cell. This binding event induces a conformational shift, primarily effecting a lever-like β-flap region, with two known orientations. We uncovered a mechanism for this allosteric transition using extensive atomistic molecular dynamics simulations and computational and experimental mutagenesis. The mechanism relies on a switchable interaction network. The most prominent interaction pair is K600-E743, with K600 interactions explaining ∼70% of the allosteric effect. Rather than gradually morphing between two end states, the interaction network adopts two mutually exclusive configurations in the active and inactive state. Similar switchable networks may explain allostery more broadly. This mechanism in particular could aid in drug development targeting the C. difficile toxins autoproteolysis.

Bioengineered Probiotics for Clostridioides difficile Infection: An Overview of the Challenges and Potential for This New Treatment Approach

The rapid increase in microbial antibiotic resistance in Clostridioides difficile (C. difficile) strains and the formation of hypervirulent strains have been associated with a global increase in the incidence of C. difficile infection (CDI) and subsequently, an increase in the rate of recurrence. These consequences have led to an urgent need to develop new and promising alternative strategies to control this pathogen. Engineered probiotics are exciting new bacterial strains produced by editing the genome of the original probiotics. Recently, engineered probiotics have been used to develop delivery vehicles for vaccines, diagnostics, and therapeutics. Recent studies have demonstrated engineered probiotics may potentially be an effective approach to control or treat CDI. This review provides a brief overview of the considerations for engineered probiotics for medicinal use, with a focus on recent preclinical research using engineered probiotics to prevent or treat CDI. We also address the challenges faced in the production of engineered strains and how they may be overcome in the application of these agents to meet patient needs in the future.

Polymorphonuclear neutrophil depletion in ileal tissues reduces the immunopathology induced by Clostridioides difficile toxins

INTRODUCTION

Clostridioides difficile, a leading cause of healthcare-associated infections, causes significant morbidity and mortality. Its pathogenesis centers on TcdA and TcdB toxins, which disrupt intestinal integrity, trigger inflammation, and promote extensive neutrophil infiltration.

OBJECTIVE

The main objective of this study was to evaluate the role of PMNs in CDI using neutrophil depletion in a murine-ileal-ligated loop.

METHODS

Mice were treated with C. difficile toxins TcdA, TcdB, and TcdBv, with PMN depletion achieved via intraperitoneal injections of Ly6G/Ly6C antibody. Histopathological analysis, cytokine quantification, and MPO activity assays were performed to assess the inflammatory and tissue damage responses.

RESULTS

PMN depletion significantly reduced histopathological damage and proinflammatory responses. TcdA induced the highest inflammation and epithelial damage, while TcdB showed lower activity, except for MPO. TcdBvNAP1's activity was comparable to that of TcdBNAP1 but less than TcdA. The findings indicate that TcdA's enterotoxin effects are more damaging than TcdBs from different strains and confirm the critical role of PMNs in CDI pathogenesis.

CONCLUSION

Our results show that PMN depletion reduced inflammatory responses and tissue damage, highlighting potential therapeutic strategies targeting PMN regulation. Further research on PMN extracellular traps (NETs) and their role in CDI is necessary to develop comprehensive treatments. Future studies should focus on combined in vivo and in vitro approaches to fully understand the pathological mechanisms and identify effective biomarkers for CDI therapy.

Advances in Fecal Microbiota Transplantation for Gut Dysbiosis-Related Diseases

This article provides an overview of the advancements in the application of fecal microbiota transplantation (FMT) in treating diseases related to intestinal dysbiosis. FMT involves the transfer of healthy donor fecal microbiota into the patient's body, aiming to restore the balance of intestinal microbiota and thereby treat a variety of intestinal diseases such as recurrent Clostridioides difficile infection (rCDI), inflammatory bowel disease (IBD), constipation, short bowel syndrome (SBS), and irritable bowel syndrome (IBS). While FMT has shown high efficacy in the treatment of rCDI, further research is needed for its application in other chronic conditions. This article elaborates on the application of FMT in intestinal diseases and the mechanisms of intestinal dysbiosis, as well as discusses key factors influencing the effectiveness of FMT, including donor selection, recipient characteristics, treatment protocols, and methods for assessing microbiota. Additionally, it emphasizes the key to successful FMT. Future research should focus on optimizing the FMT process to ensure long-term safety and explore the potential application of FMT in a broader range of medical conditions.

A systematic review of the avian antibody (IgY) therapeutic effects on human bacterial infections over the decade

The overuse of antibiotics worldwide, especially during the Coronavirus pandemic, has raised concerns about the rise of antibiotic resistance and its side effects. Immunoglobulin Y, a natural protein that specifically targets foreign antigens, holds promise as a potential therapeutic option, particularly for individuals with sensitive immune systems. Despite numerous studies on IgY, the optimal administration method, effective dose, target antigen, and potential side effects of this antibody remain areas of active research and challenge. This review selected and evaluated articles published in the last ten years from databases such as PubMed and Science Direct with appropriate keywords discussing the therapeutic effects of immunoglobulin Y in human infections in vivo. Out of all the reviewed articles, 35 articles met the inclusion criteria. The results showed that the specific antibody against dental, respiratory, and skin infections has an acceptable effectiveness. In contrast, some infections, such as neurological infections, including tetanus and botulism, still need further investigation due to the short survival time of mice. On the other hand, reporting side effects such as antibody-dependent enhancement in some infections limits its use.

Association Between Antimicrobials and Pump Proton Inhibitors Consumption with the Incidence of Nosocomial Clostridiodes difficile Infection in High Complexity Hospitals in Costa Rica

Background: Exposure to antimicrobials and Proton Pump Inhibitors (PPIs) are modifiable risk factors for nosocomial Clostridiodes difficile infection (CDI). We investigated the association between these agents and nosocomial CDI over five years. Methods: Nosocomial CDI from January 2017 to December 2021 were included. Consumption trends were analyzed using a simple linear regression model. A correlation analysis was performed using Spearman's test in two ways: without a time interval and with 1-month interval matching. An interrupted time-series method to evaluate the impact of three key temporal breakpoints on CDI incidence rate was performed using the Poisson regression model. Results: A downward trend for cephalexin, ceftriaxone, clindamycin, gentamicin, macrolides, metronidazole, and penicillin sodium was identified. In contrast, an upward trend was recognized for amoxicillin, ceftazidime/avibactam, ertapenem, fluconazole, ketoconazole, levofloxacin, and tigecycline. Among the antimicrobials that showed a positive association between consumption and the incidence of CDI are clindamycin and cephalosporins after immediate consumption. Moreover, macrolides and metronidazole presented a positive correlation, in both immediate and delayed consumption. PPIs consumption did not show changes and was not associated with nosocomial CDI incidence. The interrupted time series analysis showed no changes at the breakpoints selected. Conclusions: Consumption of clindamycin, cephalosporins, and macrolides showed positive association with CDI, despite having a downtrend in consumption. Specific events, such as the COVID-19 pandemic and the implementation of ASP, have had no correlation with CDI. Further analysis is required in Latin America to advance our understanding of risk factors associated with CDI.

DMoVGPE: predicting gut microbial associated metabolites profiles with deep mixture of variational Gaussian Process experts

BACKGROUND

Understanding the metabolic activities of the gut microbiome is vital for deciphering its impact on human health. While direct measurement of these metabolites through metabolomics is effective, it is often expensive and time-consuming. In contrast, microbial composition data obtained through sequencing is more accessible, making it a promising resource for predicting metabolite profiles. However, current computational models frequently face challenges related to limited prediction accuracy, generalizability, and interpretability.

METHOD

Here, we present the Deep Mixture of Variational Gaussian Process Experts (DMoVGPE) model, designed to overcome these issues. DMoVGPE utilizes a dynamic gating mechanism, implemented through a neural network with fully connected layers and dropout for regularization, to select the most relevant Gaussian Process experts. During training, the gating network refines expert selection, dynamically adjusting their contribution based on the input features. The model also incorporates an Automatic Relevance Determination (ARD) mechanism, which assigns relevance scores to microbial features by evaluating their predictive power. Features linked to metabolite profiles are given smaller length scales to increase their influence, while irrelevant features are down-weighted through larger length scales, improving both prediction accuracy and interpretability.

CONCLUSIONS

Through extensive evaluations on various datasets, DMoVGPE consistently achieves higher prediction performance than existing models. Furthermore, our model reveals significant associations between specific microbial taxa and metabolites, aligning well with findings from existing studies. These results highlight DMoVGPE's potential to provide accurate predictions and to uncover biologically meaningful relationships, paving the way for its application in disease research and personalized healthcare strategies.

Antibiotic Usage and Healthcare-Associated Clostridioides difficile in Patients with and Without COVID-19: A Tertiary Hospital Experience

Background/Objectives: Data about the relationship between COVID-19 and healthcare-associated Clostridioides difficile infection (HA-CDI) occurrence are still controversial. This study examines antibiotics associated with CDI in patients with and without COVID-19 infection. Methods: A prospective cohort study was conducted at the University Clinical Center Belgrade, Serbia, from January 2019 to December 2021. Patients with the first episode of HA-CDI without and with COVID-19 were included. Results of bacteriology analyses, demographic and clinical data, and data on antibiotic usage and daily defined doses (DDD) were collected by the hospital Infection Control Team. Results: Out of 547 HA-CDI cases, 341 (62.3%) had COVID-19 infection. HA-CDI patients with COVID-19 were significantly younger (p = 0.017) with fewer comorbidities (<0.001). Two or more antibiotics in therapy were more frequently used by those patients (p = 0.03). COVID-19 patients were treated significantly more by third- and fourth-generation cephalosporins, fluoroquinolones (p < 0.001) and macrolides (p = 0.01). Ceftriaxone had a higher median DDD in COVID-19 patients (6.00, range 1.00-20.00) compared to non-COVID-19 patients (4.00, range 1.00-14.00), (p = 0.007). Conversely, meropenem showed a lower median DDD in COVID-19 patients. Multivariate analysis identified the use of fourth-generation cephalosporins and fluoroquinolones as independent risk factors for HA-CDI in COVID-19 patients. Conclusions: Patients with HA-CDI and COVID-19 more frequently received two or more antibiotics before the onset of HAI-CDI. The third and fourth generations of cephalosporins, fluoroquinolones and macrolides were administered significantly more often in these patients. More frequent administration of ceftriaxone was observed, but the lower DDD associated with meropenem needed additional analysis.

Comprehensive review of Clostridium difficile infection: Epidemiology, diagnosis, prevention, and treatment

In recent years, nosocomial infections caused by Clostridium difficile (C. difficile) have risen, becoming a leading cause of hospital-acquired diarrhea. The global prevalence of C. difficile infection (CDI) varies across regions and populations. The diagnosis relies primarily on laboratory testing, including toxin, glutamate dehydrogenase, and nucleic acid amplification tests. Treatment strategies for CDI include antimicrobial therapy (e.g., metronidazole, vancomycin, and fidamycin), fecal transplantation, and immunotherapy (e.g., belotozumab), depending on the patient's specificity and severity. This paper reviews recent research on CDI's epidemiological characteristics, risk factors, diagnosis, treatment, and prevention, aiming to support hospitals and public health initiatives in implementing effective detection, prevention, and treatment strategies.

A Simple Prediction Model for Clostridioides difficile Infection: A Hospital-Based Administrative Database Study

BACKGROUND AND AIM

Few prediction scores for Clostridioides difficile infection (CDI), a potentially life-threatening nosocomial diarrhea, combine high accuracy with simplicity. A simple prediction score for routine clinical practice is needed.

METHODS

We conducted a retrospective cohort study of all inpatients aged ≥ 18 at a secondary care hospital in Japan. The derivation and validation cohorts consisted of patients from January 2016 to December 2020 and January 2021 to September 2022, respectively. Demographic and clinical data were retrieved using electronic medical records and an administrative database. The primary outcome was to derive and validate an accurate, simple prediction score for primary hospital-onset CDI. A derived prediction score by logistic regression analysis was calibrated and validated.

RESULTS

CDI developed in 102 of 25 517 and 25 of 6259 patients in the derived and validation cohorts (2.7 cases/10 000 patient-days). The derived model for predicting CDI, including antibiotic use, acid suppressant (proton pump inhibitors or vonoprazan) use, Charlson comorbidity index, and Barthel index, yielded c-statistics of 0.89 and 0.82 in the derivation and validation cohort. The model was well calibrated.

CONCLUSIONS

This simple prediction score enables early medical intervention and modification of treatment plans to reduce the risk of developing primary hospital-onset CDI.

Demographic characteristics and clinical and laboratory features of patients with Clostridiodes difficile infection: A retrospective study in Qatar

Objectives

Clostridioides difficile infection (CDI) is one of the most common causes of diarrhea in healthcare facilities, imposing a significant burden on health-related budgets and resources worldwide. We aimed to study the demographic features, laboratory findings, and outcomes of CDI in Qatar.

Methods

A retrospective study involving adult patients with a confirmed diagnosis of CDI was conducted.

Results

Of the 595 patients, 308 (51.8%) were men with a mean age of 58 ± 19.9 years. The median duration of symptoms was 2 days, with an interquartile range values of 2-4 days. The most common symptoms reported were diarrhea (90.6%) and abdominal pain (41.5%). A total of 426 (71.6%) and 422 (70.9%) patients had a history of exposure to antibiotics and proton pump inhibitors, respectively, while 461 (77.7%) patients had a history of contact with a healthcare facility in the prior 3 months. Respiratory tract infections (33.9%) and urinary tract infections (22.4%) were the most common indications for antibiotic use in the study population. Increased C-reactive protein levels were the most frequently observed laboratory findings. Sepsis was identified as the most common complication (10.4 %). Reinfection was observed in 75 (12.6%) patients. Vancomycin monotherapy was the most commonly prescribed treatment.

Conclusions

In Qatar, CDI remains a significant health concern, primarily affecting elderly men, especially those who have had hospital admissions or used proton pump inhibitors or antibiotics. Preventive measures and increased knowledge of contact precautions and hand hygiene, particularly among healthcare workers, will help to reduce transmission. Raising physician awareness regarding the prudent use of antibiotics and antibiotic stewardship will serve as an adjunct to reduce the incidence of CDIs.

Insights into the Interaction Between Clostridioides difficile and the Gut Microbiome

Clostridioides difficile (C. difficile) is a significant healthcare-associated pathogen that is predominantly caused by antibiotic-induced microbiota disturbance. Antibiotics decrease microbial diversity, resulting in C. difficile colonization and infection. Clostridium difficile infection (CDI) manifests through toxins A and B, causing diarrhea and colitis. Antibiotic usage, old age, and hospitalization are significant risk factors. A healthy gut microbiota, which is dominated by Firmicutes and Bacteroidetes, provides colonization resistance to C. difficile due to competition for nutrients, creating inhibitory substances and stimulating the immune response. Antibiotic-induced dysbiosis decreases resistance, allowing C. difficile spores to transform into vegetative forms. Patients with CDI have decreased gut microbiota diversity, with a decrease in beneficial bacteria, including Bacteroidetes, Prevotella, and Bifidobacterium, and a rise in harmful bacteria like Clostridioides and Lactobacillus. This disparity worsens the infection's symptoms and complicates therapy. Fecal Microbiota Transplantation (FMT) has emerged as a potential therapy for recurrent CDI by restoring gut microbiota diversity and function. Comprehending the connection between gut microbiota and CDI pathogenesis is critical for establishing effective preventive and treatment plans. Maintaining a healthy gut microbiota through careful antibiotic use and therapeutic options such as FMT can help in the management and prevention of CDI.

Evaluating Bezlotoxumab-Fidaxomicin Combination Therapy in Clostridioides Infection: A Single-Center Retrospective Study from Aichi Prefecture, Japan

Background/Objectives:Clostridioides difficile infection (CDI) poses a significant healthcare challenge, with recurrence rates reaching 30%, leading to substantial morbidity and costs. Fidaxomicin (FDX) and bezlotoxumab (BEZ) have shown potential in reducing recurrence; however, real-world data on the efficacy of their combination in high-risk CDI patients remain limited. This study aimed to evaluate the efficacy and safety of FDX + BEZ compared with FDX alone in CDI patients with recurrence risk factors. Methods: CDI patients with ≥two recurrence risk factors treated with FDX alone or FDX + BEZ were analyzed. Sixteen factors were evaluated as risk factors for recurrent CDI based on findings from previous studies. Patients with FDX treatment duration <10 days or other CDI treatment prior to FDX were excluded. Outcomes included recurrence within 2 months, global and clinical cure rates, and adverse events. Univariate and multivariate analyses were performed to evaluate efficacy. Results: Among 82 patients, the FDX + BEZ group (n = 30) demonstrated significantly higher global (86.7% vs. 65.4%; p < 0.05) and clinical cure rates (90.0% vs. 69.2%; p < 0.05) compared with the FDX-alone group (n = 52), despite more severe cases in the combination group. Recurrence rates were non-significantly lower in the FDX + BEZ group (3.3% vs. 11.5%). Combination therapy also accelerated diarrhea resolution without additional adverse events. Multivariate analysis identified FDX + BEZ as significantly associated with improved clinical cure (adjusted odds ratio 4.167; 95% CI: 1.029-16.885). Conclusions: FDX + BEZ therapy offers superior efficacy and safety in CDI patients with recurrence risk factors, presenting a promising strategy for optimizing CDI management.

Association Between Reporting Antimicrobial Use and Clostridioides difficile Standardized Infection Ratios in South Carolina Hospitals

The Centers for Disease Control and Prevention have been encouraging hospitals in the United States to report antimicrobial use (AU) to the National Healthcare Safety Network (NHSN). This retrospective cohort study examines the association between reporting AU and the Clostridioides difficile infection (CDI) standardized infection ratio (SIR) in South Carolina hospitals. Student's t-test was used to examine the mean difference in the change in CDI SIRs from 2017 to 2021 between hospitals reporting AU for ≥3 years and those reporting AU for <3 years during the study period. Among 65 hospitals in South Carolina, 43 reported AU for <3 years, and 22 reported AU for ≥3 years. There was significantly greater decline in the CDI SIR from 2017 to 2021 in hospitals reporting AU for ≥3 years compared to those reporting AU for <3 years (mean difference of the change in the CDI SIR -0.33 [95% CI -0.57, -0.06]; p = 0.016). The results of a steeper decline in the CDI SIR in hospitals consistently reporting AU during the majority of the study period compared to other hospitals encourages hospitals to report AU to the NHSN and promotes antimicrobial stewardship efforts at the state and national level.

The Role of Clostridioides difficile Within the One Health Framework: A Review

Clostridioides difficile is the leading cause of antibiotic-associated diarrhea in hospitalized patients. In recent years, the incidence of C. difficile infection (CDI) has increased globally, with a notable rise in community-associated CDI (CA-CDI). The presence of the microorganism in animals, the environment, and food suggests that these sources may contribute to the spread of the infection in the community. This review applies a One Health approach, integrating human, animal, and environmental health, to provide a comprehensive strategy for understanding and managing this pathogen. Findings reveal the widespread dissemination of C. difficile in animals, the environment, and food. The predominant PCR ribotypes identified were RTs 078 and 014/020, followed by RTs 126, 001, 002, 009, 010, and 033. C. difficile strains exhibited resistance to multiple antimicrobial agents, including clindamycin, erythromycin, fluoroquinolones, cephalosporins, and tetracyclines. Discriminative typing methods, such as whole-genome sequencing, revealed clonal relationships between C. difficile strains from humans and animals, indicating either direct transmission or a common environmental source of infection. The high genetic similarity between isolates from the environment and humans indicates potential environmental contamination. Additionally, clusters of C. difficile strains found in food and humans indicate a possible foodborne transmission route. This review summarizes the current knowledge on the role of Clostridioides difficile within the One Health framework.

Diagnostic and therapeutic management of Clostridioides difficile infection

A review of the diagnostic and therapeutic management algorithm of the pathogen Clostridioides difficile for daily practice is presented. Its diagnosis, in any unformed stool sample sent to the laboratory, is based on a two-step algorithm, with demonstration of the pathogen by means of its enzyme glutamate dehydrogenase by immunoassay and subsequent PCR (polymerase chain reaction) of its toxin. The mainstay of step therapy, reserved for symptomatic patients, is fidaxomicin, over vancomycin. Metronidazole is not an adequate treatment. Emerging therapies, such as faecal microbiota transplantation or the antibody bezlotoxumab, are gaining importance in patients with risk factors or relapses. Surgery is indicated in patients with worse prognosis and complications. Prevention is essential, based on vigilance and contact precautions, in addition to the elimination of spores from the environment.

Recognition, Diagnosis, and Treatment of Clostridioides difficile Enterocolitis Presenting Without Diarrhea: A Literature Review

Diarrhea, as the well-known clinical feature of Clostridioides difficile infection (CDI), may be absent at the initial presentation, leading to delays in diagnosis. The delay is due to both underrecognition of such presentations and the dependence of CDI diagnosis on stool samples. This review was conducted to evaluate the literature for CDI cases presenting without diarrhea, raise awareness about the possibility of CDI in the differential diagnosis regardless of diarrhea, and assemble relevant data to harmonize clinical approaches. The PubMED Medline database was used to conduct this literature review, focusing on reported CDI cases presenting without diarrhea. After exclusions, 22 articles were included for analysis, providing data for 48 cases. This paper will present the selected clinical data of these 48 patients and follow a real-life case with a clinical course of CDI including presentation, diagnosis, management, and outcomes. The excessive mortality and bowel resection rates of CDI patients presenting without diarrhea were the notable findings. Poor prognosis was possibly inflated by delayed diagnoses in an unfamiliar setting, emphasizing the importance of a high index of suspicion to allow early recognition of CDIs in the appropriate clinical context despite the absence of diarrhea.

Clinical characteristics and risk factors of Clostridioides difficile infection in children with diarrhoea

Objective

To investigate the clinical characteristics and risk factors of Clostridioides difficile infection (CDI) in children with diarrhea, and to provide evidence for the clinical prevention and treatment of CDI.

Methods

The clinical data of 192 children with diarrhoea suspected of CDI admitted from August 2020 to March 2023 were retrospectively analysed and divided into two groups according to whether CDI occurred, and the clinical characteristics and risk factors of the two groups were analysed statistically.

Results

There were 85 cases of CDI in children with diarrhoea, 60 males (70.6%) and 25 females (29.4%), with a male to female ratio of 2.4:1; clinical manifestations were mostly fever, diarrhoea, abdominal pain, vomiting and blood in stool, with no statistically significant differences compared to the non-infected group. Interleukin - 6 (IL - 6) levels were lower in the CDI group than in the non - CDI group, and the difference was statistically significant (P < 0.05). Multi-factor logistic regression analysis was used to show that a history of hospitalisation within the last three months, a history of antibiotic treatment for ≥7 days, non-breastfeeding, and a history of antibiotic combined with probiotic treatment were risk factors for CDI in children with diarrhoea (P < 0.05).

Conclusions

A history of hospitalisation within the last three months, previous antibiotic treatment for ≥7 days or combined with probiotic treatment, and non-breastfeeding are risk factors for CDI in children with diarrhoea, so children with diarrhoea who present as described above need to be alerted to CDI and are advised to have active investigations to facilitate rapid and effective control of the disease and improve prognosis.

Extraintestinal Clostridium difficile infection presenting as spontaneous bacterial peritonitis

Clostridioides difficile (C. difficile) infections (CDIs) are typically intestinal but can also present extraintestinally, a rare occurrence with limited literature. This case describes a woman with cirrhosis who developed spontaneous bacterial peritonitis (SBP) caused by monomicrobial extraintestinal CDI, successfully treated with metronidazole. Despite no symptoms of infection, routine paracentesis revealed ascitic fluid indicative of SBP and subsequent cultures identified C. difficile Imaging ruled out secondary peritonitis, and she had no recent abdominal surgery or enteric symptoms. The literature suggests that extraintestinal CDI accounts for 0.17%-1.08% of CDIs, with most cases being polymicrobial and often associated with traditional risk factors like antibiotic exposure and hospitalisations. However, CDI-related SBP is exceedingly rare, with only 11 cases reported, primarily in men with cirrhosis. Treatment varies with poor prognosis and low recurrence rates. This case highlights the complexity and challenges in managing extraintestinal CDI.

Analysis of high-molecular-weight proteins using MALDI-TOF MS and machine learning for the differentiation of clinically relevant Clostridioides difficile ribotypes

PURPOSE

Clostridioides difficile is the main cause of antibiotic related diarrhea and some ribotypes (RT), such as RT027, RT181 or RT078, are considered high risk clones. A fast and reliable approach for C. difficile ribotyping is needed for a correct clinical approach. This study analyses high-molecular-weight proteins for C. difficile ribotyping with MALDI-TOF MS.

METHODS

Sixty-nine isolates representative of the most common ribotypes in Europe were analyzed in the 17,000-65,000 m/z region and classified into 4 categories (RT027, RT181, RT078 and 'Other RTs'). Five supervised Machine Learning algorithms were tested for this purpose: K-Nearest Neighbors, Support Vector Machine, Partial Least Squares-Discriminant Analysis, Random Forest (RF) and Light-Gradient Boosting Machine (GBM).

RESULTS

All algorithms yielded cross-validation results > 70%, being RF and Light-GBM the best performing, with 88% of agreement. Area under the ROC curve of these two algorithms was > 0.9. RT078 was correctly classified with 100% accuracy and isolates from the RT181 category could not be differentiated from RT027.

CONCLUSIONS

This study shows the possibility of rapid discrimination of relevant C. difficile ribotypes by using MALDI-TOF MS. This methodology reduces the time, costs and laboriousness of current reference methods.

Genomic analysis reveals the presence of hypervirulent and fluoroquinolone-resistant Clostridioides difficile in farmed mussels (Mytilus galloprovincialis) in Slovenia

Clostridioides difficile is one of the leading causes of antibiotic-associated diarrhea. In this study, we characterized 76C. difficile isolates, obtained from three Mediterranean mussel (Mytilus galloprovincialis) farms in Slovenia from November 2014 to October 2015 (sampling period 1) and from January to December 2021 (sampling period 2). The overall isolation rate of C. difficile from all the examined mussels was 59.8 %. A statistically significant trend of seasonal variation was observed, with a higher isolation rate in the colder months of the year (87.9 %; sea temperature ≤ 15 °C) compared with the warmer months (31.8 %; sea temperature > 15 °C). Whole-genome sequencing (WGS) revealed that the isolates belonged to 31 different sequence types (STs), which were associated with three clades (1, 4, and 5) and two cryptic clades (C-II and C-III). Five isolates, which belonged to ST11 (clade 5), harbored all the main toxin genes (A+B+CDT+) and chromosomal mutations conferring fluoroquinolone resistance. Core genome multilocus sequence typing (cgMLST) revealed four clusters of 2-3 isolates, three of which included isolates from different farms, suggesting that clonal C. difficile strains are circulating among the Slovenian mussel farms. The results highlight the presence of hypervirulent strains in mussels; therefore, at-risk population groups should be alerted to the risks associated with consuming shellfish.

Risk Factors for Clostridium difficile Infection in Inpatients: A Four-Year (2017-2020) Retrospective Study

BACKGROUND

Clostridium difficile infection (CDI) impact on healthcare systems is concerning due to high treatment cost and increased hospitalization time. We found that the incidence rate of CDI increased annually at Taipei Medical University Hospital (TMUH). The study aimed to establish monitoring indicators for hospitalized patients receiving antibiotics to prevent CDI occurrences.

METHODS

A case-control study was conducted to identify the risk factors of CDI among patients who were admitted to TMUH and tested for C. difficile. Patient demographics, patient history, and laboratory data were collected and analyzed.

RESULTS

Nutrition Risk Screening 2002 score (NRS 2002) in CDI patients was significantly lower than in non-CDI patients (3.1 ± 1.7 vs. 3.5 ± 1.6). The percentage of tube feeding in CDI patients was significantly lower than in non-CDI patients (23.0% vs. 36.7%), whereas parenteral nutrition was higher (8.8% vs. 3.8%). Age (OR = 1.03, p = 0.00), NRS 2002 score (OR =0.86, p = 0.05), comorbidity with cardiovascular disease (OR = 1.73, p = 0.03) or pulmonary disease (OR = 3.72, p = 0.00), patients with tube feeding (OR = 2.02, p = 0.01), and the number of medications (OR = 1.15, p < 0.01) were significant predictors of CDI.

CONCLUSION

This study revealed that nutritional factors, including NRS 2002 scores and feeding routes, were associated with CDI, emphasizing the importance of nutritional factors as key predictors in managing and preventing CDI.

Heterogeneity of Clostridioides difficile asymptomatic colonization prevalence: a systematic review and meta-analysis

BACKGROUND

Asymptomatic carriers significantly influence the transmission dynamics of C. difficile. This study aimed to assess the prevalence of toxigenic C. difficile asymptomatic colonization (tCDAC) and investigate its heterogeneity across different populations. We searched MEDLINE, Web of Science, and Scopus for articles published between 2000 and 2023 on tCDAC. Studies including asymptomatic adults with laboratory-confirmed tCDAC were eligible. We performed a random-effects meta-analysis to estimate the pooled prevalence by clinical characteristics, settings, and geographic areas. In addition, we used outlier analyses and meta-regression to explore sources of prevalence variability.

RESULTS

Fifty-one studies involving 39,447 patients were included. The tCDAC prevalence ranged from 0.5 to 51.5%. Among pooled estimates, a high prevalence was observed in patients with cystic fibrosis, outbreak settings, and cancer patients, whereas the lowest rates were found in healthy individuals and healthcare workers. Similar colonization rates were observed between admitted and hospitalized patients. Our meta-regression analysis revealed lower rates in healthy individuals and higher rates in cystic fibrosis patients and studies from North America. Additionally, compared with that among healthy individuals, the prevalence significantly increased by 15-47% among different populations and settings.

CONCLUSION

Our study revealed that tCDAC is a common phenomenon. We found high prevalence estimates that showed significant variability across populations. This heterogeneity could be partially explained by population characteristics and settings, supporting their role in the pathogenesis and burden of this disease. This highlights the need to identify high-risk groups to improve infection control strategies, decrease transmission dynamics, and better understand the natural history of this disease.

Bile acids as germinants for Clostridioides difficile spores, evidence of adaptation to the gut?

Bacterial spores formed upon metabolic stress have minimal metabolic activity and can remain dormant for years. Nevertheless, they can sense the environment and germinate quickly upon exposure to various germinants. Germinated spores can then outgrow into vegetative cells. Germination of spores of some anaerobes, especially Clostridioides difficile, is triggered by cholic acid and taurocholic acid. Elevated levels of these bile acids are thought to correlate with a perturbed gut microbiome, which cannot efficiently convert primary bile acids into secondary bile acids. That bile acids are germination-triggers suggests these bacteria have a life cycle taking place partially in the mammalian digestive tract where bile acids are plentiful; notably bile acids can be made by all vertebrates. Thus, spores survive in the environment until taken up by a host where they encounter an environment suitable for germination and then proliferate in the largely anaerobic large intestine; some ultimately sporulate there, regenerating environmentally resistant spores in the C. difficile life cycle. This review summarizes current literature on the effects of bile acids and their metabolites on spore germination in the gut and evidence that adaptation to bile acids as germinants is a consequence of a life cycle both inside and outside the digestive tract.

Phocaeicola vulgatus shapes the long-term growth dynamics and evolutionary adaptations of Clostridioides difficile

Clostridioides difficile can transiently or persistently colonize the human gut, posing a risk for infections. This colonization is influenced by complex molecular and ecological interactions with the human gut microbiota. By investigating C. difficile dynamics in human gut communities over hundreds of generations, we show patterns of stable coexistence, instability, or competitive exclusion. Lowering carbohydrate concentrations shifted a community containing C. difficile and the prevalent human gut symbiont Phocaeicola vulgatus from competitive exclusion to coexistence, facilitated by increased cross-feeding. In this environment, two key mutations in C. difficile altered its metabolic niche from proline to glucose utilization. These metabolic changes in C. difficile substantially impacted gut microbiota inter-species interactions and reduced disease severity in mice. In sum, interactions with P. vulgatus are crucial in shaping the long-term growth dynamics and evolutionary adaptations of C. difficile, offering key insights for developing anti-C. difficile strategies.

Pilot study of Clostridioides difficile infection (CDI) in hospitals, Italy, September to December 2022

BackgroundClostridioides difficile infection (CDI) is a severe infection that needs to be monitored. This infection predominantly occurs in hospitalised patients after antimicrobial treatment, with high mortality in elderly patients.AimWe aimed at estimating the incidence of CDI in Italian hospitals over 4 months in 2022.MethodsWe estimated incidences of hospital-acquired CDI (HA-CDI), community or unknown CDI (CA/UA-CDI), recurrent CDI and overall CDI in 25 Italian hospitals, characterised C. difficile isolates using PCR ribotyping, analysed them for toxin genes and susceptibility to antimicrobials.ResultsClostridioides difficile was detected in 9.7% (655/6,722) of samples from 550 patients, 18 patients died of CDI. The mean overall CDI incidence was 5.0 cases per 10,000 patient days (range: 0.7-11.9). For HA-CDI, mean incidence was 3.7 (range: 0.7-9.2), for CA/UA-CDI 0.8 (range: 0.0-3.2) and for recurrent CDI 0.5 (range: 0.0-3.4). Most patients were female (n = 295; 53.6%), aged ≥ 65 years (n = 422; 76.7%) and previously hospitalised (n = 275; 50.0%). Of the 270 culturable isolates, 267 (98.9%) had toxin A and B genes and 51 (18.9%) the binary toxin genes. Of the 55 PCR ribotypes (RTs) identified, RT 018 (n = 56; 20.7%) and RT 607 (n = 23; 8.5%) were the most common, RT 607 in the northern (p < 0.0001) and RT 018 in the central (p < 0.0001) regions of Italy. Most isolates (n = 158; 58.5%) were antimicrobial-resistant and 119 (44.1%) were multidrug-resistant (MDR).ConclusionHighly virulent and MDR C. difficile types are circulating in Italian hospitals which highlights the need of robust surveillance and stringent prevention and control measures.

Biological Mechanisms of Polyphenols against Clostridium Difficile: A Systematic Review

BACKGROUND

Clostridium difficile is an opportunistic infection that can lead to antibiotic- associated diarrhea and toxic megacolon.

OBJECTIVE

This systematic review study aimed to investigate polyphenols' antibacterial and antitoxin properties and their effects on reducing complications related to C. difficile Infections (CDI).

METHODS

This systematic review was conducted following the PRISMA guideline 2020. Multiple databases, including Web of Science, PubMed, Cochrane Library, EMBASE, and Scopus, were searched thoroughly for existing literature. After considering the inclusion and exclusion criteria for the review, 18 articles were included. Data were collected and registered into an Excel file for further investigations and conclusions.

RESULTS

Polyphenols by reducing Reactive Oxygen Species (ROS) levels, increasing inflammatory factor Interleukin 10 (IL-10), reducing Nuclear Factor kappa B (NF-κB) and Tumour Necrosis Factor- α (TNF-α), IL-6, IL-1α, IL-1β, Granulocyte Colony-stimulating Factor (G-CSF), and Monocyte Chemoattractant Protein-1 (MCP-1) and Macrophage Inflammatory Protein-1 alpha (MIP-1α) levels, and regulating the expression of Bcl-2 and Bax, make the growth and replication conditions of C. difficile more difficult and prevent it from producing toxins. Furthermore, polyphenols can exhibit prebiotic properties, promoting the growth of beneficial Bifidobacterium and Lactobacillus species and consequently regulating gut microbiota, exerting antimicrobial activities against C. difficile. They also induce their beneficial effects by inhibiting the production of C. difficile TcdA and TcdB.

CONCLUSION

Polyphenols have been reported to inhibit C. difficile growth and toxin production by several mechanisms in preclinical studies. However, more clinical studies are needed to investigate their safety in humans.

Clostridioides difficile infection increases in-hospital mortality, length of stay, and hospital cost but not 30-day mortality in cirrhotic patients

BACKGROUND AND AIM

Clostridioides difficile infection (CDI) is a leading cause of nosocomial infection and is associated with both higher morbidity and mortality. Cirrhotic patients are more susceptible to CDI because of impaired gut immune response, use of proton pump inhibitor, and frequent hospitalization. We aim to investigate the impact of CDI on cirrhotic patients' in-hospital and 30-day mortality, length of stay, and hospital cost.

METHODS

Potentially eligible studies were identified from Embase, Medline, and Web of Sciences databases.

RESULTS

A total of 2320 articles were identified. After reviewing, nine studies reporting in-hospital mortality and three reporting 30-day mortality of cirrhotic patients with CDI versus those without CDI were included. The meta-analysis of nine studies, consisting of 7 746 126 patients, revealed a significant association between CDI and in-hospital mortality in cirrhotic patients with the pooled OR of 1.68 (95% CI 1.29-1.85, I2 94%). Length of stay and hospital cost were also higher in the CDI group (pooled MD of 6.56 days [95% CI 5.75-7.36, I2 94%] and 27.85 (×$1000) [95% CI 10.41-45.29, I2 100%], respectively). The funnel plots for the meta-analysis of the association between CDI and in-hospital mortality, length of stay, and hospitalization cost were not suggestive of publication bias. From three studies consisting of 3694 patients, we found that CDI was not associated with 30-day mortality in cirrhotic patients (pooled OR 1.20, 95% CI 0.75-2.24, I2 74%).

CONCLUSION

CDI is associated with increased in-hospital mortality, length of stay, and hospital costs, but not with 30-day mortality in cirrhotic patients.

Effects of Antimicrobial Agents Used for Dental Treatments: Impacts on the Human Oral Ecosystem and the Resistome

Antimicrobial resistance (AMR) is a major public health concern, especially with regard to bacterial resistance to antibiotics. Dentists are responsible for approximately 10% of all antibiotic prescriptions. In addition, there seems to be a lack of awareness of potential resistance toward antiseptics and biocides such as chlorhexidine digluconate (CHX) or cetylpyridinium chloride (CPC), which are commonly used in dental practice but also included in over-the-counter products. In comparison to the gut microbiome, only a small number of studies have investigated the impact of antibiotics on the oral microbiome. Amoxicillin is a commonly prescribed antibiotic in dentistry, often used in combination with metronidazole. Several studies have addressed its impact on the oral microbiome. Similarly, the effects of ciprofloxacin, clindamycin, cephazolin, and benzylpenicillin have also been examined in various studies. However, due to variations in study designs, it is difficult to compare the effects of antibiotics on the oral microbiota, and conclusions can only be drawn at the phyla level. In contrast, studies on CPC and CHX have also focused on the genus level. The oral resistome mainly contains genes involved in resistance to macrolides, MLSB (macrolide, lincosamide, and streptogramin B), lincosamide and streptogramin A, fluoroquinolone, tetracycline, or penicillin. The oral cavity therefore serves as a reservoir for antibiotic resistance genes (ARGs), which are of crucial importance both for inflammations in the oral cavity and for the treatment of the entire human organism. Therefore, dentists must weigh up the benefits and risks of using antibiotics very carefully.

Superiority of frailty over age in predicting outcomes among clostridium difficile patients: Evidence from national data

BACKGROUND

Clostridium difficile infection (CDI) has become a significant healthcare issue with increasing morbidity and mortality in the US and Europe. Frailty, characterized by reduced physical reserves and resistance to stressors, is linked to poor outcomes but its impact on CDI patients remains underexplored. This study seeks to address this gap through a nationwide analysis.

METHODS

Using the National Readmission Database from 2016 to 2020, we employed the International Classification of Diseases, 10th revision, Clinical Modifications codes to identify adult patients admitted with CDI. We further stratified CDI hospitalizations based on frailty. Utilizing a regression model, we assessed the impact of frailty on CDI outcomes.

RESULTS

We included 144,611 CDI patients of whom 98,167 (67.88 %) were frail. Multivariate analysis showed that frail CDI patients had significantly higher mortality (adjusted odds ratio (aOR) 4.87), acute kidney injury requiring dialysis (aOR 9.50), septic shock (aOR 14.23), and intensive care unit admission (aOR 6.80). CDI-specific complications were more likely in frail patients, including toxic megacolon (aOR 10.22), intestinal perforation (aOR 2.30), need for colectomy (aOR 3.90) and CDI recurrence (aOR 3.65). Resource utilization, indicated by hospitalization charges, length of stay, and 30-day readmission rates, was greater among frail patients.

CONCLUSION

Our study underscores the significant association between frailty and various critical endpoints of CDI, including its incidence, mortality, and recurrence. Additionally, frailty independently predicts higher resource utilization and elevated 30-day readmission. Recognizing frailty as a determinant of CDI outcomes can aid clinicians in risk stratification and guide tailored interventions for this population.

Early treatment for Clostridioides difficile infection: retrospective cohort study

INTRODUCTION

Clostridioides difficile (CDI) is a common cause of infectious diarrhea. The current recommendation is to initiate empirical antibiotic treatment for suspected CDI who have an anticipated delay of confirmatory results or fulminant colitis. This is based on limited clinical trials. The study aims to examine the impact of early treatment on mortality and clinical outcomes.

METHODS

This retrospective cohort study included adult patients with CDI. Early treatment was defined as the initiation of an anti-Clostridioides medication within the first 24 h following stool sampling. Outcomes were 30 and 90 day mortality, length of hospital stay (LOS), recurrence, and colectomy rate. To address potential bias, propensity score matching followed by logistic regression was performed, P value less than 5% was considered statistically significant.

RESULTS

Study cohort consisted of 796 patients; clinical characteristics were balanced following matching. There was no difference, in favor of early treatment, between the groups regarding 30 day mortality and 90 day mortality with HR of 0.91 (95% CI 0.56-1.47) and 0.7 (95% CI 0.45-1.08), respectively. No statistically significant difference in recurrence rate, ICU admission or colectomy rate was observed. The LOS was shorter in the early-treatment group with 6 days vs. 8 days.

CONCLUSION

Early treatment for CDI had shortened hospital stay. However, it did not affect clinical outcomes in adult patients.

A Review of Therapies for Clostridioides difficile Infection

Clostridioides difficile is an urgent public health threat that affects approximately half a million patients annually in the United States. Despite concerted efforts aimed at the prevention of Clostridioides difficile infection (CDI), it remains a leading cause of healthcare-associated infections. CDI is associated with significant clinical, social, and economic burdens. Therefore, it is imperative to provide optimal and timely therapy for CDI. We conducted a systematic literature review and offer treatment recommendations based on available evidence for the treatment and prevention of CDI.

PPAR-γ agonist mitigates intestinal barrier dysfunction and inflammation induced by Clostridioides difficile SlpA in vitro

Clostridioides difficile is the leading cause of healthcare- and antibiotic-associated diarrhea. Surface layer protein A (SlpA), an essential component of the bacterium's outermost layer, contributes to colonization and inflammation. The peroxisome proliferator-activated receptor gamma (PPAR-γ) has been demonstrated to improve intestinal integrity and prevent inflammation in host cells. Here, we investigated the role of PPAR-γ in SlpA-mediated inflammation in Caco-2 cells and THP-1 derived macrophages. The extraction of SlpA was carried out for three toxigenic C. difficile clinical strains (RT126, RT001, RT084) and a non-toxigenic strain (ATCC 700057). The gene expression of tight junction (TJ) proteins and inflammatory markers was determined using RT-qPCR. The production of proinflammatory cytokines and nitric oxide was measured by ELISA and Griss reaction, respectively. Western blotting was performed to detect PPAR-γ level before and after adding its agonist, pioglitazone. SlpA of C. difficile strains enhanced the expression of TLR-4, NF-κB, MyD88, IL-17, MCP-1, IL-8, IL-6, TNF-α, IL-1β, whilst the gene expression level of JAM-A, claudin-1, occludin, PPAR-γ and its receptor (CD36) was decreased in both Caco-2 cells and THP-1 derived macrophages. Moreover, pioglitazone caused a notable elevation in the expression level of PPAR-γ, only following treatment with RT126 SlpA. Besides, pioglitazone pretreatment improved TJ impairment in Caco-2 cells and attenuated proinflammatory cytokine expression in both SlpA-treated cell lines. SlpA can attenuate PPAR-γ expression, trigger TJ disruption, and stimulate inflammatory response in host cells. Notably, these events could be reversed by pretreatment of cells with PPAR-γ agonist. Further experiments are required to corroborate the present findings.

Targeting Spore-Forming Bacteria: A Review on the Antimicrobial Potential of Selenium Nanoparticles

Spore-forming bacterial species pose a serious threat to food plants and healthcare facilities that use high-temperature processing and sterilizing techniques to sanitize medical equipment and food items. These severe processing conditions trigger sporulation, which is the process by which spore-forming bacteria, such as those of the Bacillus and Clostridium species, begin to produce spores, which are extremely resilient entities capable of withstanding adverse environmental circumstances. Additionally, these spores are resistant to a wide range of disinfectants and antibacterial therapies, such as hydrolytic enzymes, radiation, chemicals, and antibiotics. Because of their ability to combat bacteria through several biological pathways, selenium nanoparticles (SeNPs) have emerged as an effective method for either eliminating or preventing the formation of spore-forming bacteria. This review aims to investigate every potential pathway of entry and mechanism by which SeNPs impact bacterial species that produce spores. Additionally, SeNPs' antibacterial efficacy against several infections is reviewed. To precisely explain the antibacterial mechanism of SeNPs and the various factors that can affect their effectiveness, more research is necessary.

The Use of Gel Electrophoresis to Separate Multiplex Polymerase Chain Reaction Amplicons Allows for the Easy Identification and Assessment of the Spread of Toxigenic Clostridioides difficile Strains

Clostridioides difficile is a common etiological factor of hospital infections, which, in extreme cases, can lead to the death of patients. Most strains belonging to this bacterium species synthesize very dangerous toxins: toxin A (TcdA) and B (TcdB) and binary toxin (CDT). The aim of this study was to assess the suitability of agarose gel electrophoresis separation of multiplex PCR amplicons to investigate the toxinogenic potential of C. difficile strains. Additionally, the frequency of C. difficile toxin genes and the genotypes of toxin-producing strains were determined. Ninety-nine C. difficile strains were used in the detection of the presence of genes encoding all of these toxins using the multiplex PCR method. In 85 (85.9%) strains, the presence of tcdA genes encoding enterotoxin A was detected. In turn, in 66 (66.7%) isolates, the gene encoding toxin B (tcdB) was present. The lowest number of strains tested was positive for genes encoding a binary toxin. Only 31 (31.3%) strains possessed the cdtB gene and 22 (22.2%) contained both genes for the binary toxin subunits (the cdtB and cdtA genes). A relatively large number of the strains tested had genes encoding toxins, whose presence may result in a severe course of disease. Therefore, the accurate diagnosis of patients, including the detection of all known C. difficile toxin genes, is very important. The multiplex PCR method allows for the quick and accurate determination of whether the tested strains of this bacterium contain toxin genes. Agarose gel electrophoresis is a useful tool for visualizing amplification products, allowing one to confirm the presence of specific C. difficile toxin genes as well as investigate their dissemination for epidemiological purposes.

Hospitalized patients on proton pump inhibitors for stress ulcer prophylaxis have a higher risk of Clostridioides difficile infection compared with those on histamine-2 receptor antagonists

BACKGROUND

Previous studies on Clostridioides difficile infection (CDI) in proton pump inhibitor (PPI) users generally enrolled a heterogeneous population and did not include a control group of histamine H2 receptor antagonists (H2RAs) users or adjust for confounding variables, such as previous antibiotics. It is uncertain whether hospitalized patients using PPIs for stress ulcer prophylaxis (SUP) are at a higher risk of CDI compared with those using H2RAs. This study aimed to compare the association between CDI and the usage of antisecretory drugs (ASDs): PPIs and H2RAs, for SUP among hospitalized patients, and the impact of the duration of their use on CDI.

METHODS

In this nationwide population-based cohort study using the Taiwan National Health Insurance Database, hospitalized patients using ASDs for SUP were identified between 2017 and 2018. A total of 63,266 and 69,269 individuals were included in the PPI and H2RA groups, respectively. The primary endpoint was a 90-day monitoring of CDI occurrence.

FINDINGS

The incidences of CDI were 1.6/10,000 and 0.5/10,000 person-days in the PPIs and H2RAs groups, respectively. After adjusting for confounding factors, the risk of infection in the PPIs group remained significantly higher than in the H2RAs group (hazard ratio (HR), 2.49; 95% confidence interval (CI), 1.63-3.81). In the subgroup analysis, during hospitalization, the risk of CDI for patients using high-risk antibiotics or admitted to the intensive care unit (ICU), as well as patients with immunodeficiency, using PPIs for SUP, was higher than using H2RAs. Furthermore, the risk of CDI was higher in patients using ASDs for durations >14 days than in those using them for <7 days (adjusted HR, 3.66; 95% CI, 2.34-5.75).

CONCLUSIONS

The risk of occurrence CDI for hospitalized patients using PPIs for SUP was higher than using H2RAs. It is recommended not to exceed 14 days of any gastric ASDs for SUP during hospitalization, especially for patients who have used high-risk antibiotics, have been admitted to the ICU, or have immunodeficiency.

Cleavage of cell junction proteins as a host invasion strategy in leptospirosis

Infection and invasion are the prerequisites for developing the disease symptoms in a host. While the probable mechanism of host invasion and pathogenesis is known in many pathogens, very little information is available on Leptospira invasion/pathogenesis. For causing systemic infection Leptospira must transmigrate across epithelial barriers, which is the most critical and challenging step. Extracellular and membrane-bound proteases play a crucial role in the invasion process. An extensive search for the proteins experimentally proven to be involved in the invasion process through cell junction cleavage in other pathogens has resulted in identifying 26 proteins. The similarity searches on the Leptospira genome for counterparts of these 26 pathogenesis-related proteins identified at least 12 probable coding sequences. The proteins were either extracellular or membrane-bound with a proteolytic domain to cleave the cell junction proteins. This review will emphasize our current understanding of the pathogenic aspects of host cell junction-pathogenic protein interactions involved in the invasion process. Further, potential candidate proteins with cell junction cleavage properties that may be exploited in the diagnostic/therapeutic aspects of leptospirosis will also be discussed. KEY POINTS: • The review focussed on the cell junction cleavage proteins in bacterial pathogenesis • Cell junction disruptors from Leptospira genome are identified using bioinformatics • The review provides insights into the therapeutic/diagnostic interventions possible.

Incidence and Risk Factors of Clostridium difficile Infection Among Adult Patients Admitted to the Inpatient Department of a Tertiary Care Hospital: A Hospital-Based Observational Study

Background Clostridium difficile infection (CDI) is a significant healthcare concern, marked by its rising prevalence and associated morbidity and mortality. However, there is limited data on the epidemiology of CDI in the eastern region of India. Objectives The study aims to determine the incidence of CDI among adult patients admitted to the inpatient department of a tertiary care hospital and identify the risk factors associated with CDI. Methodology A prospective observational study was conducted at a tertiary care hospital between October 2022 and March 2023. Using universal sampling, 200 adult patients were included in the study. Stool samples were collected within 24 hours of admission and again on the day of discharge or after one week, whichever period was longer. Relevant clinical, demographic, and laboratory data were also collected. The stool samples were analyzed for C. difficile toxins A and B using an enzyme immunoassay. Statistical analysis was performed using the mean and independent t-test for continuous variables, while proportions and Chi-square or Fisher's exact tests were applied for categorical variables. Results The incidence of CDI during the study period was 9%. The participants had a mean age of 46.49 ± 16.78 years, with a predominance of males (60%). Acute febrile illness was the most common diagnosis at admission (36%). The mean duration of hospitalization was significantly longer in patients who tested positive for C. difficile toxins via enzyme-linked immunosorbent assay compared to those who tested negative (8.0 ± 1.53 days vs. 3.75 ± 1.25 days, p < 0.001). Exposure to broad-spectrum antibiotics, particularly third-generation cephalosporins, was significantly associated with CDI development. Additionally, fecal leukocytes were detected in all (100%) patients who tested positive for C. difficile toxins. Conclusions This study offers important insights into the incidence and risk factors of CDI among adult patients in a tertiary care setting. The findings emphasize the need for the judicious use of broad-spectrum antibiotics to reduce the risk of CDI. Additionally, the detection of fecal leukocytes may serve as a valuable diagnostic marker for CDI in clinical practice.

Pilot of a bowel habit assessment tool to enable early identification of Clostridioides difficile infection

Objective

To develop a symptom assessment tool to assist health care providers with discussing bowel habits in a sensitive and accurate method.

Design

Pre and Post education survey.

Setting

180 bed academically affiliated Veterans Affairs Hospital.

Participants

Nurses, nursing assistants and physicians who participated in a brief educational session.

Methods

A Bowel Habits Assessment Tool (BHAT) was developed to assist health care providers in learning skills to assess patient bowel habits accurately. The BHAT was introduced at educational sessions. An anonymous pre and post survey employing a 5-point Likert scale was administered to participants.

Results

Pre-educational session survey results for Question 1 (Q1) "I am comfortable discussing patient's bowel habits included: 4.6% strongly disagreed or somewhat disagreed, 3% neither agreed nor disagreed, 20% somewhat agreed and 72.3% strongly agreed. After the BHAT education, 100% (n=65) of participants strongly agreed or somewhat agreed that they were comfortable discussing patient's bowel habits. Q1 pre/post mean difference 0.25 (CI 0.06539 - 0.4269, p = 0.0084). On the pre-survey, only 34% of participants strongly agreed that they were aware of tools to help discuss patients' bowel habits. This increased to 77% after the BHAT educational session. (Q2). Q2 pre/post mean difference 1.02 (CI 0.7366 - 1.294, p <0.0001).

Conclusions

The BHAT improved clinicians' comfort level discussing patient's bowel habits. Health care providers found the BHAT useful and related to their work. This tool shows promise in improving providers' comfort discussing bowel habits and diagnosing Clostridioides difficile in a timely manner.

Gut microbiota and skin pathologies: Mechanism of the gut-skin axis in atopic dermatitis and psoriasis

Atopic dermatitis (AD) and psoriasis are chronic skin diseases with a global impact, posing significant challenges to public health systems and severely affecting patients' quality of life. This review delves into the key role of the gut microbiota in these diseases, emphasizing the importance of the gut-skin axis in inflammatory mediators and immune regulation and revealing a complex bidirectional communication system. We comprehensively assessed the pathogenesis, clinical manifestations, and treatment strategies for AD and psoriasis, with a particular focus on how the gut microbiota and their metabolites influence disease progression via the gut-skin axis. In addition, personalized treatment plans based on individual patient microbiome characteristics have been proposed, offering new perspectives for future treatment approaches. We call for enhanced interdisciplinary cooperation to further explore the interactions between gut microbiota and skin diseases and to assess the potential of drugs and natural products in modulating the gut-skin axis, aiming to advance the treatment of skin diseases.

EAVLD 2024 - 7th Congress of the European Association of Veterinary Laboratory Diagnosticians

This abstract book contains the abstracts presented at the 7th Congress of the European Association of Veterinary Laboratory Diagnosticians.

Polysaccharides of natural products alleviate antibiotic-associated diarrhea by regulating gut microbiota: a review

Antibiotic-associated diarrhea (AAD) is diarrhea caused by disturbances in intestinal microbiota and metabolism following inappropriate use of antibiotics. With the over-reliance on antibiotics, the incidence of AAD is increasing worldwide. Recently, the role of probiotics and prebiotic preparations in the prevention and treatment of AAD has received increasing attention. Various prebiotics can not only reduce the incidence of AAD, but also effectively shorten the course of the disease and alleviate the symptoms. Notably, many polysaccharides derived from plants and fungi are a class of biologically active and rich prebiotics with great potential to alleviate AAD. Therefore, this review aims to summarize the latest research on natural product polysaccharides to alleviate antibiotic-associated diarrhea by modulating the gut microbiota. It provides a theoretical basis for exploring the mechanism of natural product modulation of gut microbiota to alleviate AAD, and provides a reference for further development of active prebiotics.

NKp46+ ILC3s promote early neutrophil defense against Clostridioides difficile infection through GM-CSF secretion

Clostridioides difficile infection (CDI) is a common cause of antibiotic-associated colitis. C. difficile proliferates and produces toxins that damage the colonic epithelium, leading to symptoms ranging from mild diarrhea to severe pseudomembranous colitis. The host's innate response to CDI occurs in two phases: an early phase in which neutrophils reduce the bacterial load and a late phase involving repair mechanisms to restore epithelial integrity. Group 3 innate lymphoid cells (ILC3s) are crucial in protecting the gut from CDI. Previous studies have shown that ILC3-derived IL-22 is essential in the late phase of CDI for epithelial repair and maintaining an intestinal microbiota that competes with C. difficile, preventing its expansion. Our study finds that ILC3s also protect during the early stages of CDI by sustaining neutrophils through GM-CSF. Less neutrophil production, accumulation, and activation was evident in ILC3-deficient mice than in wild-type (WT) mice, which led to exacerbated symptoms, impaired pathogen clearance, a compromised epithelial barrier, and increased mortality. The adoptive transfer of ILC3s into ILC3-deficient mice restored neutrophil responses and improved disease outcomes. Both in vitro and in vivo experiments revealed that GM-CSF production by ILC3s is crucial for neutrophil production and effective resistance during CDI. Using mice lacking NKp46+ ILC3s, we found that this subset significantly contributes to GM-CSF production in CDI. These findings highlight the critical role of the ILC3-neutrophil connection in early innate responses to CDI. Enhancing ILC3 production of GM-CSF could be a promising strategy for improving host defense against CDI and other enteric infections.