Global burden of Clostridium difficile infections: a systematic review and meta-analysis

Gut Microbiota and New Microbiome-Targeted Drugs for Clostridioides difficile Infections

Clostridioides difficile is a major causative pathogen for antibiotic-associated diarrhea and C. difficile infections (CDIs) may lead to life-threatening diseases in clinical settings. Most of the risk factors for the incidence of CDIs, i.e., antibiotic use, treatment by proton pump inhibitors, old age, and hospitalization, are associated with dysbiosis of gut microbiota and associated metabolites and, consequently, treatment options for CDIs include normalizing the composition of the intestinal microbiome. In this review, with an introduction to the CDI and its global epidemiology, CDI-associated traits of the gut microbiome and its metabolites were reviewed, and microbiome-targeting treatment options were introduced, which was approved recently as a new drug by the United States Food and Drug Administration (U.S. FDA), rather than a medical practice.

Multicomponent Approaches to Reduce Multidrug-Resistant Organisms in Critical Care: Determining the Ideal Strategy

Although there is ample proof of the advantages of infection prevention and Control (IPC) in acute-care hospitals, there is still some questions about the efficacy of IPC interventions for multidrug-resistant organisms (MDROs), and there is a need for the development of evidence-based practices. No healthcare facility has found a single effective technique to reduce MDRO. However, a multicomponent intervention that included improved barrier protection, chlorhexidine bathing, microbiological monitoring, and staff involvement significantly decreased the likelihood of infection in the patient surroundings with multidrug-resistant organisms. A practical strategy suited to reducing the burden of MDROs and their transmission potential in the critical care unit must be established in light of the global development of AMR. In this review, we summarize key findings of a multicomponent approaches to reduce MDROs in critical care units.

Analysis of factors affecting the length of hospitalization of patients with Clostridioides difficile infection: a cross-sectional study

BACKGROUND

Clostridioides difficile infection (CDI) is an infectious disease caused by the gram-positive, anaerobic bacterium C. difficile. The vulnerable populations for CDI include the elderly, immunocompromised individuals, and hospitalized patients, especially those undergoing antimicrobial therapy, which is a significant risk factor for this infection. Due to its complications and increased resistance to treatment, CDI often leads to longer hospital stays. This study aimed to determine the average length of hospital stay (LOS) of Polish patients with CDI and to identify factors affecting the LOS of infected patients.

METHODS

The study analyzed medical records of adult patients treated with CDI in one of the biggest clinical hospitals in Poland between 2016-2018. Information encompassed the patient's age, LOS results of selected laboratory tests, number of antibiotics used, nutritional status based on Nutritional Risk Screening (NRS 2002), year of hospitalization, presence of diarrhea on admission, systemic infections, additional conditions, and undergone therapies. The systematic collection of these variables forms the foundation for a comprehensive analysis of factors influencing the length of stay.

RESULTS

In the study period, 319 patients with CDI were hospitalized, with a median LOS of 24 days (min-max = 2-344 days). The average LOS was 4.74 days in 2016 (median = 28 days), 4.27 days in 2017 (median = 24 days), and 4.25 days in 2018 (median = 23 days). There was a weak negative correlation (Rho = -0.235, p < 0.001) between albumin level and LOS and a weak positive correlation between NRS and LOS (Rho = 0.219, p < 0.001). Patients admitted with diarrhea, a history of stroke or pneumonia, those taking certain antibiotics (penicillins, cephalosporins, carbapenems, fluoroquinolones, aminoglycosides, colistin), and those using proton pump inhibitors, exhibited longer hospitalizations (all p < 0.001) or unfortunately died (p = 0.008). None of the individual predictors such as albumin level, Nutritional Risk Screen, pneumonia, stroke, and age showed a statistically significant relationship with the LOS (p > 0.05). However, the multivariate regression model explained a substantial portion of the variance in hospitalization length, with an R-squared value of 0.844.

CONCLUSIONS

Hospitalization of a patient with CDI is long. Low albumin levels and increased risk of malnutrition were observed in longer hospitalized patients. Longer hospitalized patients had pneumonia, stroke, or surgery, and were admitted for a reason other than CDI.

Gut Microbial and Metabolic Features Associated With Clostridioides difficile Infection Recurrence in Children

Background

Recurrent Clostridioides difficile infection (CDI) is a critical clinical issue due to the increase in incidence and difficulty in treatment. We aimed to identify gut microbial and metabolic features associated with disease recurrence in a group of pediatric CDI patients.

Methods

A total of 84 children with primary CDI were prospectively enrolled in the study. Fecal samples collected at the initial diagnosis were subjected to 16S rRNA gene sequencing and targeted metabolomics analysis to profile the bacterial composition and metabolome.

Results

Twenty-six of 84 (31.0%) pediatric CDI patients experienced recurrence. The alpha diversity of the fecal microbiota was significantly lower in the recurrent group than in the nonrecurrent group, and the beta diversity was different from that of the nonrecurrent group. Taxonomic profiles revealed that the relative abundances of multiple bacterial taxa significantly differed between the recurrent and nonrecurrent groups. Linear discriminant analysis effect size analysis identified several bacterial genera that discriminated between recurrent and nonrecurrent groups, including Parabacteroides, Coprococcus, Dialister, and Clostridium. Recurrent bacteria presented lower abundances of several short-chain fatty acid (SCFA)-producing bacteria (Faecalibacterium, Butyricicoccus, Clostridium, Roseburia, and Ruminococcus), which were correlated with reduced fecal SCFA levels. In addition, several bile acids, including lithocholic acid (LCA), 12-ketoLCA, trihydroxycholestanoic acid, and deoxycholic acid, were decreased in recurrent patients.

Conclusions

Our study suggests that the differing gut microbiota profiles in pediatric CDI patients may contribute to disease recurrence by modulating SCFA concentrations and bile acid profiles. The gut microbiota and metabolite signatures may be used to predict disease recurrence in children with CDI.

Retrospective, propensity score--matched study examining the relationship between frailty and Clostridioides difficile infection in a national cohort of US veterans

BACKGROUND

Frailty is often more predictive of disease and mortality compared with chronological age. This study determined the impact of frailty on Clostridioides difficile infection (CDI) risk and outcomes in a national veteran population.

METHODS

This was a retrospective cohort study of CDI and control veteran inpatients and outpatients from fiscal year 2003 to 2018. Baseline frailty was presented as the Veterans Affairs (VA) Frailty Index. Propensity score--matched analyses were conducted to compare CDI risk, CDI health outcomes, and 1-year new-onset frailty-associated conditions.

RESULTS

A total of 11,451 CDI and 11,451 matched control patients were included. Baseline frailty conditions were more common among CDI patients, especially involuntary weight loss (6.0% vs 3.4%, P < .001) and anemia (24.6% vs 18.7%, P < .001). VA Frailty Index was significantly higher for CDI patients (0.13 vs 0.11, P = .019). Frail CDI patients were more likely to experience 30-day mortality (11.3% vs 1.1%, P < .001) and 60-day CDI recurrence (20.4% vs 16.3%, P < .001) compared with non-/prefrail CDI patients. At 1year, CDI patients were significantly more likely to be categorized as frail (19.6% vs 17.0%, P < .001).

CONCLUSIONS

This study demonstrated the potential association between frailty and CDI risk and health outcomes, as well as new-onset frailty diagnoses in patients who develop CDI.

Best Practices in the Management of Clostridioides difficile Infection in Developing Nations

Clostridioides difficile infection (CDI) is a well-known cause of hospital-acquired infectious diarrhea in developed countries, though it has not been a top priority in the healthcare policies of developing countries. In the last decade, several studies have reported a wide range of CDI rates between 1.3% and 96% in developing nations, raising the concern that this could represent a healthcare threat for these nations. This review defines developing countries as those with a human development index (HDI) below 0.8. We aim to report the available literature on CDI epidemiology, diagnostics, management, and prevention in developing countries. We identify limitations for CDI diagnosis and management, such as limited access to CDI tests and unavailable oral vancomycin formulation, and identify opportunities to enhance CDI care, such as increased molecular test capabilities and creative solutions for CDI. We also discuss infection prevention strategies, including antimicrobial stewardship programs and opportunities emerging from the COVID-19 pandemic, which could impact CDI care.

A New Convenient Method to Assess Antibiotic Resistance and Antimicrobial Efficacy against Pathogenic Clostridioides difficile Biofilms

Clostridioides difficile is a widely distributed anaerobic pathogen. C. difficile infection is a serious problem in healthcare. Its biofilms have been found to exhibit biocorrosivity, albeit very little, but sufficient for it to correlate with biofilm growth/health. This work demonstrated the use of a disposable electrochemical biofilm test kit using two solid-state electrodes (a 304 stainless steel working electrode, and a graphite counter electrode, which also served as the reference electrode) in a 10 mL serum vial. It was found that the C. difficile 630∆erm Adp-4 mutant had a minimum inhibitory concentration (MIC) for vancomycin twice that of the 630∆erm wild type strain in biofilm prevention (2 ppm vs. 1 ppm by mass) on 304 stainless steel. Glutaraldehyde, a commonly used hospital disinfectant, was found ineffective at 2% (w/w) for the prevention of C. difficile 630∆erm wild type biofilm formation, while tetrakis(hydroxymethyl)phosphonium sulfate (THPS) disinfectant was very effective at 100 ppm for both biofilm prevention and biofilm killing. These antimicrobial efficacy data were consistent with sessile cell count and biofilm imaging results. Furthermore, the test kit provided additional transient biocide treatment information. It showed that vancomycin killed C. difficile 630∆erm wild type biofilms in 2 d, while THPS only required minutes.

Prevalence of Enteric Pathogens and Antibiotic Resistance: Results of a Six-Year Active Surveillance Study on Patients Admitted to a Teaching Hospital

BACKGROUND

Acute Infectious Diarrhea (AID) and the short- and long-term complications associated with it are major causes of hospitalization worldwide. In Italy, due to a lack of robust surveillance programs, only limited data has been collected on their prevalence and circulation. This study aims to evaluate the resistance pattern of enteric pathogens and their epidemiological trends over a six-year period.

METHODS

This cross-sectional retrospective study was conducted from January 2018 to December 2023. Stool samples were analyzed during routine diagnosis with culture methods, syndromic molecular tests, and enzyme immunoassay.

RESULTS

Bacteria were the most isolated enteric pathogens (62.2%), followed by fungi (29.0%), viruses (8.2%), and parasites (0.6%). Most bacteria were isolated from outpatients (29.5%) and from patients in the Oncology ward (26.2%). The most prevalent target was EPEC (11.1%), followed by C. difficile toxin A/B-producing strains (8.3%), C. jejuni (2.5%), and S. enterica, (1%.). Norovirus and Candida spp. were the most prevalent in pediatric patients (6.5% and 39.6%, respectively). In the last years, enteric pathogens have been a frequent cause of infections characterized by a problematic resistance to common antimicrobials. In our study, S. enterica showed resistance to amikacin, gentamicin, ampicillin, levofloxacin, and ciprofloxacin. C. jejuni was susceptible to all tested drugs.

CONCLUSION

Timely notification of gastroenteric infections is crucial in identifying potential outbreak sources and ensuring strict adherence to food safety and hygiene practices, so as to protect the most vulnerable populations. The present study offers insights into the epidemiological characteristics and the antibiotic susceptibility of the main enteric AID pathogens in order to implement infection control measures in health care settings.

Metagenome-assembled genomes (MAGs) suggest an acetate-driven protective role in gut microbiota disrupted by Clostridioides difficile

Clostridioides difficile may have a negative impact on gut microbiota composition in terms of diversity and abundance, thereby triggering functional changes supported by the differential presence of genes involved in significant metabolic pathways, such as short-chain fatty acids (SCFA). This work has evaluated shotgun metagenomics data regarding 48 samples from four groups classified according to diarrhea acquisition site (community- and healthcare facility-onset) and positive or negative Clostridioides difficile infection (CDI) result. The metagenomic-assembled genomes (MAGs) obtained from each sample were taxonomically assigned for preliminary comparative analysis concerning differences in composition among groups. The predicted genes involved in metabolism, transport, and signaling remained constant in microbiota members; characteristic patterns were observed in MAGs and genes involved in SCFA butyrate and acetate metabolic pathways for each study group. A decrease in genera and species, as well as relative MAG abundance with the presence of the acetate metabolism-related gene, was evident in the HCFO/- group. Increased antibiotic resistance markers (ARM) were observed in MAGs along with the genes involved in acetate metabolism. The results highlight the need to explore the role of acetate in greater depth as a potential protector of the imbalances produced by CDI, as occurs in other inflammatory intestinal diseases.

Commensal-pathogen dynamics structure disease outcomes during Clostridioides difficile colonization

Gastrointestinal colonization by Clostridioides difficile is common in healthcare settings and ranges in clinical presentation from asymptomatic carriage to lethal C. difficile infection (CDI). We used a systems biology approach to investigate why patients colonized with C. difficile have a range of outcomes. Microbiota-humanization of germ-free mice with fecal samples from toxigenic C. difficile carriers revealed a spectrum of virulence among clade 1 lineages and identified commensal Blautia associated with markers of non-pathogenic colonization. Using gnotobiotic mice engrafted with defined human microbiota, we observed strain-specific CDI severity across clade 1 strains. Yet, mice engrafted with a higher diversity community were protected from severe disease across all strains without suppression of C. difficile colonization. These results indicate that when colonization resistance has been breached without overt infection, commensals can attenuate a diversity of virulent strains without inhibiting pathogen colonization, providing insight into determinants of stable C. difficile carriage.

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.

Fecal microbiota live - jslm (Rebyota™/RBL) for management of recurrent Clostridioides difficile infection

There is an unmet need for effective treatments of Clostridioides difficile infection, an emerging health crisis in the United States. The management of C. difficile infection should include treatment of active infection and a strategy to prevent recurrence. Current gold standard therapy includes oral antibiotics which predispose patients to gut dysbiosis and increase the risk of recurrent infection. Addressing dysbiosis via fecal microbiota transplantation is an active and promising area of research, but studies have lacked standardization which makes outcome and safety data difficult to interpret. Rebyota™, formerly known as RBX2660, is a live biotherapeutic product designed using a standardized protocol and manufacturing process that has been shown to be effective for preventing recurrent C. difficile infection.

[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.

Comparative genome analyses of clinical and non-clinical Clostridioides difficile strains

The pathogenic bacterium Clostridioides difficile is a worldwide health burden with increasing morbidity, mortality and antibiotic resistances. Therefore, extensive research efforts are made to unravel its virulence and dissemination. One crucial aspect for C. difficile is its mobilome, which for instance allows the spread of antibiotic resistance genes (ARG) or influence strain virulence. As a nosocomial pathogen, the majority of strains analyzed originated from clinical environments and infected individuals. Nevertheless, C. difficile can also be present in human intestines without disease development or occur in diverse environmental habitats such as puddle water and soil, from which several strains could already be isolated. We therefore performed comprehensive genome comparisons of closely related clinical and non-clinical strains to identify the effects of the clinical background. Analyses included the prediction of virulence factors, ARGs, mobile genetic elements (MGEs), and detailed examinations of the pan genome. Clinical-related trends were thereby observed. While no significant differences were identified in fundamental C. difficile virulence factors, the clinical strains carried more ARGs and MGEs, and possessed a larger accessory genome. Detailed inspection of accessory genes revealed higher abundance of genes with unknown function, transcription-associated, or recombination-related activity. Accessory genes of these functions were already highlighted in other studies in association with higher strain virulence. This specific trend might allow the strains to react more efficiently on changing environmental conditions in the human host such as emerging stress factors, and potentially increase strain survival, colonization, and strain virulence. These findings indicated an adaptation of the strains to the clinical environment. Further, implementation of the analysis results in pairwise genome comparisons revealed that the majority of these accessory genes were encoded on predicted MGEs, shedding further light on the mobile genome of C. difficile. We therefore encourage the inclusion of non-clinical strains in comparative analyses.

PhosphoLipidome Alteration Induced by Clostridioides difficile Toxin B in Enteric Glial Cells

Clostridioides difficile (C. difficile) is responsible for a spectrum of nosocomial/antibiotic-associated gastrointestinal diseases that are increasing in global incidence and mortality rates. The C. difficile pathogenesis is due to toxin A and B (TcdA/TcdB), both causing cytopathic and cytotoxic effects and inflammation. Recently, we demonstrated that TcdB induces cytopathic and cytotoxic (apoptosis and necrosis) effects in enteric glial cells (EGCs) in a dose/time-dependent manner and described the underlying signaling. Despite the role played by lipids in host processes activated by pathogens, to counter infection and/or induce cell death, to date no studies have investigated lipid changes induced by TcdB/TcdA. Here, we evaluated the modification of lipid composition in our in vitro model of TcdB infection. Apoptosis, cell cycle, cell viability, and lipidomic profiles were evaluated in EGCs treated for 24 h with two concentrations of TcdB (0.1 ng/mL; 10 ng/mL). In EGCs treated with the highest concentration of TcdB, not only an increased content of total lipids was observed, but also lipidome changes, allowing the separation of TcdB-treated cells and controls into different clusters. The statistical analyses also allowed us to ascertain which lipid classes and lipid molecular species determine the clusterization. Changes in lipid species containing inositol as polar head and plasmalogen phosphatidylethanolamine emerged as key indicators of altered lipid metabolism in TcdB-treated EGCs. These results not only provide a picture of the phospholipid profile changes but also give information regarding the lipid metabolism pathways altered by TcdB, and this might represent an important step for developing strategies against C. difficile infection.

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.

Estimating excess mortality and economic burden of Clostridioides difficile infections and recurrences during 2015-2019: the RECUR Germany study

BACKGROUND

Clostridioides difficile infections (CDIs) and recurrences (rCDIs) remain a major public health challenge due to substantial mortality and associated costs. This study aims to generate real-world evidence on the mortality and economic burden of CDI in Germany using claims data between 2015 and 2019.

METHODS

A longitudinal and matched cohort study using retrospective data from Statutory Health Insurance (SHI) was conducted in Germany with the BKK database. Adults diagnosed with CDI in hospital and community settings between 2015 and 2018 were included in the study. Patients had a minimum follow-up of 12-months. All-cause mortality was described at 6-, 12-, and 24-months. Healthcare resource usage (HCRU) and associated costs were assessed at 12-months of follow-up. A cohort of non-CDI patients matched by demographic and clinical characteristics was used to assess excess mortality and incremental costs of HCRU. Up to three non-CDI patients were matched to each CDI patient.

RESULTS

A total of 9,977 CDI patients were included in the longitudinal cohort. All-cause mortality was 32%, 39% and 48% at 6-, 12-, and 24-months, respectively, with minor variations by number of rCDIs. When comparing matched CDI (n = 5,618) and non-CDI patients (n = 16,845), CDI patients had an excess mortality of 2.17, 1.35, and 0.94 deaths per 100 patient-months, respectively. HCRU and associated costs were consistently higher in CDI patients compared to non-CDI patients and increased with recurrences. Total mean and median HCRU cost per patient during follow-up was €12,893.56 and €6,050 in CDI patients, respectively, with hospitalisations representing the highest proportion of costs. A total mean incremental cost per patient of €4,101 was estimated in CDI patients compared to non-CDI patients, increasing to €13,291 in patients with ≥ 3 rCDIs.

CONCLUSIONS

In this real-world study conducted in Germany, CDI was associated with increased risk of death and substantial costs to health systems due to higher HCRU, especially hospitalisations. HCRU and associated costs were exacerbated by rCDIs.

"Primum, non nocere": The Epidemiology of Toxigenic Clostridioides difficile Strains in the Antibiotic Era-Insights from a Prospective Study at a Regional Infectious Diseases Hospital in Eastern Europe

Clostridioides difficile infection (CDI), though identified nearly five decades ago, still remains a major challenge, being associated with significant mortality rates. The strains classified as hypervirulent, notably 027/NAP1/BI, have garnered substantial attention from researchers and clinicians due to their direct correlation with the severity of the disease. Our study aims to elucidate the significance of toxigenic Clostridioides difficile (CD) strains in the clinical and therapeutic aspects of managing patients diagnosed with CDI. We conducted a single-center prospective study, including patients with CDI from north-eastern Romania. We subsequently conducted molecular biology testing to ascertain the prevalence of the presumptive 027/NAP1/BI strain within aforementioned geographic region. The patients were systematically compared and assessed both clinically and biologically, employing standardized and comparative methodologies. The study enrolled fifty patients with CDI admitted between January 2020 and June 2020. Among the investigated patients, 43 (86%) exhibited infection with toxigenic CD strains positive for toxin B genes (tcdB), binary toxin genes (cdtA and cdtB), and deletion 117 in regulatory genes (tcdC), while the remaining 7 (14%) tested negative for binary toxin genes (cdtA and cdtB) and deletion 117 in tcdC. The presence of the presumptive 027/NAP1/BI strains was linked to a higher recurrence rate (35.56%, p = 0.025), cardiovascular comorbidities (65.1% vs. 14.2%, p = 0.016), and vancomycin treatment (55.8% vs. 14.3%, p = 0.049). The findings of our investigation revealed an elevated incidence of colitis attributed to presumptive 027/NAP1/BI. Despite the prevalence of the presumptive 027 strain and its associated heightened inflammation among the patients studied, no significant differences were observed regarding the clinical course or mortality outcomes.

Clostridioides difficile infection, recurrence and the associated healthcare consumption in Sweden between 2006 and 2019: a population-based cohort study

BACKGROUND

Clostridioides difficile infection (CDI) causes a major burden to individuals and society, yet the impact may vary depending on age, sex, underlying comorbidities and where CDI was acquired (hospital or community).

METHODS

This Swedish nationwide population-based cohort study (2006-2019) compared all 43,150 individuals with CDI to their 355,172 matched controls (first year and entire follow-up). Negative binomial regression models compared the cumulated length of stay, number of in-hospital admissions, outpatient visits and prescriptions after the first CDI episode expressed as incidence rate ratios (IRR) and 95% confidence intervals for the entire follow-up.

RESULTS

Overall, 91.6% of CDI cases were hospital acquired, and 16.8% presented with recurrence(s); 74.8%of cases were ≥ 65 years and 54.2% were women. Compared to individuals without CDI, in-hospital stay rates were 18.01 times higher after CDI (95% CI 17.40-18.63, first-year: 27.4 versus 1.6 days), 9.45 times higher in-hospital admission (95% CI 9.16-9.76, first-year: 2.6 versus 1.3 hospitalisations), 3.94 times higher outpatient visit (95% CI 3.84-4.05, first-year: 4.0 versus 1.9 visits) and 3.39 times higher dispensed prescriptions rates (95% CI 3.31-3.48, first-year: 25.5 versus 13.7 prescriptions). For all outcomes, relative risks were higher among the younger (< 65 years) than the older (≥ 65 years), and in those with fewer comorbidities, but similar between sexes. Compared to those without recurrence, individuals with recurrence particularly showed a higher rate of hospital admissions (IRR = 1.18, 95% 1.12-1.24). Compared to community-acquired CDI, those with hospital-acquired CDI presented with a higher rate of hospital admissions (IRR = 7.29, 95% CI 6.68-7.96) and a longer length of stay (IRR = 7.64, 95% CI 7.07-8.26).

CONCLUSION

CDI was associated with increased health consumption in all affected patient groups. The majority of the CDI burden could be contributed to hospital-acquired CDI (~ 9/10), older patients (~ 3/4) and those with multiple comorbidities (~ 6/10 Charlson score ≥ 3), with 1/5 of the total CDI burden contributed to individuals with recurrence. Yet, relatively speaking the burden was higher among the younger and those with fewer comorbidities, compared to their peers without CDI.

Case Series: Efficacy of Polyclonal Intravenous Immunoglobulin for Refractory Clostridioides difficile Infection

BACKGROUND

Intravenous immunoglobulin (IVIg) for Clostridioides difficile infection (CDI) no longer features in treatment guidelines. However, IVIg is still used by some clinicians for severe or recurrent CDI (rCDI) cases. The main objective of this study was to investigate the efficacy of IVIg and to identify possible predictors of disease resolution post IVIg administration for patients with CDI.

METHODS

This retrospective observational cohort study of patients ≥2 years old hospitalised with severe, relapsing, or rCDI treated with IVIg therapy was performed in a large UK tertiary hospital between April 2018 and March 2023. Scanned electronic notes from patient admissions and clinical reporting systems were used to collect relevant data.

RESULTS

In total, 20/978 patients diagnosed with CDI over the 5-year study were treated with IVIg. Twelve (60%) had hospital-onset CDI. Eleven of the twenty patients (55%) responded to treatment, with a mean of 8.6 (SD 10.7) days to disease resolution. Sixteen (80%) patients were treated for severe CDI and four (20%) for rCDI (n = 3) and relapsing CDI (n = 1). There were no statistically significant differences in possible independent predictors of disease resolution post IVIg administration between groups. There was an average of 6.2 (4.9) days to IVIg administration after diagnosis with no difference between responders and non-responders (p = 0.88) and no further significant difference in additional indicators. Four (36%) of the responders were immunosuppressed compared to just one (11%) of the non-responders (p = 0.15). Six of the responders (two with recurrent and four with severe CDI) improved rapidly within 2 days, and three of these were immunosuppressed.

CONCLUSION

We observed disease resolution post IVIg therapy in over 50% of patients with refractory CDI. Our data also support a potential enhanced effect of IVIg in immunosuppressed individuals. Thus, the role of IVIg for CDI treatment, particularly in the immunosuppressed, warrants future case-control studies coupled to mechanistic investigations to improve care for this ongoing significant healthcare-associated infection.

[Fecal Microbiota Transfer (FMT) in Germany - Status and Perspective]

INTRODUCTION

Fecal microbiota transfer (FMT) is a treatment to modulate the gastrointestinal microbiota. Its use in recurrent Clostridioides difficile infection (rCDI) is established throughout Europe and recommended in national and international guidelines. In Germany, the FMT is codeable in the hospital reimbursement system. A comprehensive survey on the frequency of use based on this coding is missing so far.

MATERIAL AND METHODOLOGY

Reports of the Institute for Hospital Remuneration (InEK), the Federal Statistical Office (DESTATIS), and hospital quality reports 2015-2021 were examined for FMT coding and evaluated in a structured expert consultation.

RESULTS

Between 2015 and 2021, 1,645 FMT procedures were coded by 175 hospitals. From 2016 to 2018, this was a median of 293 (274-313) FMT annually, followed by a steady decline in subsequent years to 119 FMT in 2021. Patients with FMT were 57.7% female, median age 74 years, and FMT was applied colonoscopically in 72.2%. CDI was the primary diagnosis in 86.8% of cases, followed by ulcerative colitis in 7.6%.

DISCUSSION

In Germany, FMT is used less frequently than in the European comparison. One application hurdle is the regulatory classification of FMT as a non-approved drug, which leads to significantly higher costs in manufacturing and administration and makes reimbursement difficult. The European Commission recently proposed a regulation to classify FMT as a transplant. This could prospectively change the regulatory situation of FMT in Germany and thus contribute to a nationwide offer of a therapeutic procedure recommended in guidelines.

Clostridioides difficile recurrence in individuals with and without cancer: a Swedish population-based cohort study

PURPOSE

Patients with cancer are vulnerable to Clostridioides difficile infection (CDI) due to their disease, treatment and regular hospital contact, yet if CDI-recurrence is more common remains unclear, and differences among cancer types remain unexplored.

METHODS

This Swedish nationwide population-based cohort included all 43,150 individuals with recorded CDI (2006-2019) to assess CDI-recurrence in individuals with and without cancer, with binary multivariable logistic regression, stratified by anatomical location, and survival status.

RESULTS

Compared to those without cancer (N = 29,543), ongoing cancer (diagnosis < 12 months; N = 3,882) was associated with reduced recurrence (OR = 0.81, 95% CI 0.73-0.89), while there was no association with cancer history (diagnosis ≥ 12 months; N = 9,725). There was an increased 8-week all-cause mortality (Ongoing cancer: OR = 1.58, 95% CI 1.43-1.74; Cancer history: OR = 1.45, 95% CI 1.36-1.55) compared to those without cancer. Among CDI-survivors, those with ongoing cancer presented with a decreased odds of recurrence (OR = 0.84, 95% CI 0.76-0.94), compared to those without cancer history, with no association for those with cancer history (OR = 1.04, 95% CI 0.97-1.1). Large variations were seen across cancer types, with the highest observed proportion of recurrence in oral and mesothelial cancer, and the lowest for esophageal cancer, although no statistically significant OR were found.

CONCLUSION

The population-based study indicates that individuals with cancer may have fewerrecurrences than expected, yet variations by cancer type were large, and mortality was high.

Microbiota-Based Therapeutics as New Standard-of-Care Treatment for Recurrent Clostridioides difficile Infection

Background

Clostridioides difficile (C. difficile) is a spore-forming bacterial species that ubiquitously exists in the environment. Colonization by C. difficile is highly prevalent in infants, while fewer than 5% of adults are asymptomatic carriers. Disruption of the microbiome, such as through antibiotic treatment, triggers the germination of bacterial spores into numerous vegetative cells. These cells then produce enterotoxins that result in watery diarrhea and colonic inflammation. If left untreated, C. difficile infection (CDI) can lead to pseudomembranous colitis with the potentially life-threatening complication of toxic megacolon.

Summary

Over the past few decades, the incidence, morbidity, and mortality associated with CDIs have increased. They have emerged as the primary cause of nosocomial gastrointestinal infections in industrialized countries, posing a significant burden on healthcare systems. Despite antibiotics often being the cause of CDIs, they remain the standard treatment. However, a considerable number of patients treated with antibiotics will experience recurrent CDI (rCDI). Microbiota-based therapies targeting the core issue of CDI - antibiotic-induced dysbiosis - hold promise for rCDI treatment. While data for probiotics are insufficient, numerous studies have highlighted the effectiveness of fecal microbiota transplantation (FMT) as a safe and viable therapeutic option for rCDI. This approach is now endorsed by multiple guidelines. Nonetheless, regulatory prerequisites, such as comprehensive stool donor screening, restrict the widespread adoption of FMT beyond specialized centers. Recently, the US Food and Drug Administration has approved two commercial microbiota-based therapeutics to prevent CDI recurrence. These therapeutics are available by prescription in the USA. RBX2660 (REBYOTA™) comprises a diverse consortium of live microbes derived from human stool and is administered via enema. On the other hand, SER-109 (VOWST™) is an orally administered spore-based medication. In this review, we discuss the potential of microbiota-based treatments for rCDI against the background of medico-legal challenges associated with classical FMT.

Key Messages

FMT has emerged as a highly effective cure for rCDI. Nonetheless, regulatory prerequisites and laborious preparation procedures impede its widespread use. The establishment of ready-to-use microbiota-based therapeutics in clinical practice is necessary. In the USA, the recent approval of the first two commercial medications, including a spore-based oral preparation, marks a significant step forward.

Novel insights into phage biology of the pathogen Clostridioides difficile based on the active virome

The global pathogen Clostridioides difficile is a well-studied organism, and researchers work on unraveling its fundamental virulence mechanisms and biology. Prophages have been demonstrated to influence C. difficile toxin expression and contribute to the distribution of advantageous genes. All these underline the importance of prophages in C. difficile virulence. Although several C. difficile prophages were sequenced and characterized, investigations on the entire active virome of a strain are still missing. Phages were mainly isolated after mitomycin C-induction, which does not resemble a natural stressor for C. difficile. We examined active prophages from different C. difficile strains after cultivation in the absence of mitomycin C by sequencing and characterization of particle-protected DNA. Phage particles were collected after standard cultivation, or after cultivation in the presence of the secondary bile salt deoxycholate (DCA). DCA is a natural stressor for C. difficile and a potential prophage-inducing agent. We also investigated differences in prophage activity between clinical and non-clinical C. difficile strains. Our experiments demonstrated that spontaneous prophage release is common in C. difficile and that DCA presence induces prophages. Fourteen different, active phages were identified by this experimental procedure. We could not identify a definitive connection between clinical background and phage activity. However, one phage exhibited distinctively higher activity upon DCA induction in the clinical strain than in the corresponding non-clinical strain, although the phage is identical in both strains. We recorded that enveloped DNA mapped to genome regions with characteristics of mobile genetic elements other than prophages. This pointed to mechanisms of DNA mobility that are not well-studied in C. difficile so far. We also detected phage-mediated lateral transduction of bacterial DNA, which is the first described case in C. difficile. This study significantly contributes to our knowledge of prophage activity in C. difficile and reveals novel aspects of C. difficile (phage) biology.

Culture-independent detection of low-abundant Clostridioides difficile in environmental DNA via PCR

Clostridioides difficile represents a major burden to public health. As a well-known nosocomial pathogen whose occurrence is highly associated with antibiotic treatment, most examined C. difficile strains originated from clinical specimen and were isolated under selective conditions employing antibiotics. This suggests a significant bias among analyzed C. difficile strains, which impedes a holistic view on this pathogen. In order to support extensive isolation of C. difficile strains from environmental samples, we designed a detection PCR that targets the hpdBCA-operon and thereby identifies low abundances of C. difficile in environmental samples. This operon encodes the 4-hydroxyphenylacetate decarboxylase, which catalyzes the production of the antimicrobial compound para-cresol. Amplicon-based analyses of diverse environmental samples demonstrated that the designed PCR is highly specific for C. difficile and successfully detected C. difficile despite its absence in general 16S rRNA gene-based detection strategies. Further analyses revealed the potential of the hpdBCA detection PCR sequence for initial phylogenetic classification, which allows assessment of C. difficile diversity in environmental samples via amplicon sequencing. Our findings furthermore showed that C. difficile strains isolated under antibiotic treatment from environmental samples were originally dominated by other strains according to PCR amplicon results. This provided evidence for selective cultivation of under-represented but antibiotic-resistant isolates. Thereby, we revealed a substantial bias in C. difficile isolation and research.IMPORTANCEClostridioides difficile is a main cause of diarrheic infections after antibiotic treatment with serious morbidity and mortality worldwide. Research on this pathogen and its virulence has focused on bacterial isolation from clinical specimens under antibiotic treatment, which implies a substantial bias in isolated strains. Comprehensive studies, however, require an unbiased strain collection, which is accomplished by isolation of C. difficile from diverse environmental samples and avoidance of antibiotic-based enrichment strategies. Thus, isolation can significantly benefit from our C. difficile-specific detection PCR, which rapidly verifies C. difficile presence in environmental samples and further allows estimation of the C. difficile diversity by using next-generation sequencing.

Genomic surveillance of Clostridioides difficile transmission and virulence in a healthcare setting

Clostridioides difficile infection (CDI) is a major cause of healthcare-associated diarrhea, despite the widespread implementation of contact precautions for patients with CDI. Here, we investigate strain contamination in a hospital setting and the genomic determinants of disease outcomes. Across two wards over 6 months, we selectively cultured C. difficile from patients (n = 384) and their environments. Whole-genome sequencing (WGS) of 146 isolates revealed that most C. difficile isolates were from clade 1 (131/146, 89.7%), while only one isolate of the hypervirulent ST1 was recovered. Of culture-positive admissions (n = 79), 19 (24%) patients were colonized with toxigenic C. difficile on admission to the hospital. We defined 25 strain networks at ≤2 core gene single nucleotide polymorphisms; two of these networks contain strains from different patients. Strain networks were temporally linked (P < 0.0001). To understand the genomic correlates of the disease, we conducted WGS on an additional cohort of C. difficile (n = 102 isolates) from the same hospital and confirmed that clade 1 isolates are responsible for most CDI cases. We found that while toxigenic C. difficile isolates are associated with the presence of cdtR, nontoxigenic isolates have an increased abundance of prophages. Our pangenomic analysis of clade 1 isolates suggests that while toxin genes (tcdABER and cdtR) were associated with CDI symptoms, they are dispensable for patient colonization. These data indicate that toxigenic and nontoxigenic C. difficile contamination persist in a hospital setting and highlight further investigation into how accessory genomic repertoires contribute to C. difficile colonization and disease.

IMPORTANCE

Clostridioides difficile infection remains a leading cause of hospital-associated diarrhea, despite increased antibiotic stewardship and transmission prevention strategies. This suggests a changing genomic landscape of C. difficile. Our study provides insight into the nature of prevalent C. difficile strains in a hospital setting and transmission patterns among carriers. Longitudinal sampling of surfaces and patient stool revealed that both toxigenic and nontoxigenic strains of C. difficile clade 1 dominate these two wards. Moreover, quantification of transmission in carriers of these clade 1 isolates underscores the need to revisit infection prevention measures in this patient group. We identified unique genetic signatures associated with virulence in this clade. Our data highlight the complexities of preventing transmission of this pathogen in a hospital setting and the need to investigate the mechanisms of in vivo persistence and virulence of prevalent lineages in the host gut microbiome.

The combined effect of systemic antibiotics and proton pump inhibitors on Clostridioides difficile infection and recurrence

BACKGROUND

Antibiotics and proton pump inhibitors (PPI) are recognized risk factors for acquisition and recurrence of Clostridioides difficile infection (CDI), yet combined effects remain unclear.

OBJECTIVES

To assess the short- and long-term effects of antibiotics and PPIs on CDI risk and recurrence.

METHODS

Population-based study including all 43 152 patients diagnosed with CDI in Sweden (2006-2019), and 355 172 matched population controls without CDI. The impact of antibiotics and PPIs on CDI risk and recurrence was explored for recent (0-30 days) and preceding (31-180 days) use prior to their first CDI diagnosis, using multivariable conditional logistic regression presented as odds ratios (ORs) and 95% confidence interval, adjusted for demographics, comorbidities and other drugs.

RESULTS

Compared to controls, the combined effect of recent PPIs and antibiotics [ORAB+PPI = 17.51 (17.48-17.53)] on CDI risk was stronger than the individual effects [ORAB = 15.37 (14.83-15.93); ORPPI = 2.65 (2.54-2.76)]. Results were less pronounced for exposure during the preceding months. Dose-response analyses showed increasing exposure correlated with CDI risk [recent use: ORAB = 6.32 (6.15-6.49); ORPPI = 1.65 (1.62-1.68) per prescription increase].Compared to individuals without recurrence (rCDI), recent [ORAB = 1.30 (1.23-1.38)] and preceding [ORAB = 1.23 (1.16-1.31); ORPPI = 1.12 (1.03-1.21)] use also affected the risk of recurrence yet without significant interaction between both. Recent macrolides/lincosamides/streptogramins; other antibacterials including nitroimidazole derivates; non-penicillin beta lactams and quinolones showed the strongest association with CDI risk and recurrence, particularly for recent use. PPI use, both recent and preceding, further increased the CDI risk associated with almost all antibiotic classes.

CONCLUSION

Recent and less recent use of PPIs and systemic antibiotics was associated with an increased risk of CDI, particularly in combination.

Clostridioides difficile infections, recurrences, and clinical outcomes in real-world settings from 2015 to 2019: The RECUR England study

OBJECTIVE

To estimate the epidemiological and clinical burden of Clostridioides difficile infections (CDIs) and recurrences (rCDIs) in England.

METHODS

This retrospective study included adult patients diagnosed with CDI (community or hospital settings) over 2015-2019 from Clinical Practice Research Datalink and Hospital Episode Statistics databases. Incidences of CDI and rCDI were determined annually. Time to subsequent rCDI was estimated by Kaplan-Meier method. Rates of complications were assessed within 12 months from index episode. Association of risk factors with complications was evaluated using a Cox regression model.

RESULTS

A total of 52,443 CDI episodes were recorded among 36,913 patients. Of these, 75% were aged ≥65 years, 59% were women; 73% were treated in community settings. CDI incidence remained stable (111 episodes per 100,000 patients in 2019). Around 21% of patients had ≥1 rCDI. Sepsis (12%) was the most common complication, followed by colectomy and ulcerative colitis. Age, gender, comorbidities, rCDI, preindex medical procedures, hospitalizations and consultations, and CDI treatment in hospital, were found to increase the risk of complication.

CONCLUSIONS

CDI remains a concern in England. The study highlights the importance of managing primary and rCDI episodes via effective and improved therapies to prevent fatal complications.

Advances in Therapeutic Strategies for the Management of Clostridioides difficile Infection

The infection caused by Clostridioides difficile represents one of the bacterial infections with the greatest increase in incidence among nosocomial infections in recent years. C. difficile is a Gram-positive bacterium able to produce toxins and spores. In some cases, infection results in severe diarrhoea and fulminant colitis, which cause prolonged hospitalisation and can be fatal, with repercussions also in terms of health economics. C. difficile is the most common cause of antibiotic-associated diarrhoea in the healthcare setting. The problem of bacterial forms that are increasingly resistant to common antibiotic treatments is also reflected in C. difficile infection (CDI). One of the causes of CDI is intestinal dysmicrobialism induced by prolonged antibiotic therapy. Moreover, in recent years, the emergence of increasingly virulent strains resistant to antibiotic treatment has made the picture even more complex. Evidence on preventive treatments to avoid recurrence is unclear. Current guidelines indicate the following antibiotics for the treatment of CDI: metronidazole, vancomycin, and fidaxomycin. This short narrative review provides an overview of CDI, antibiotic resistance, and emerging treatments.

A Real-World Study on the Clinical Characteristics, Outcomes, and Relationship between Antibiotic Exposure and Clostridioides difficile Infection

Clostridioides difficile is a Gram-positive bacteria that causes nosocomial infections, significantly impacting public health. In the present study, we aimed to describe the clinical characteristics, outcomes, and relationship between antibiotic exposure and Clostridioides difficile infection (CDI) in patients based on reports from two databases. Thus, we conducted a retrospective study of patients diagnosed with CDI from Sibiu County Clinical Emergency Hospital (SCCEH), Romania, followed by a descriptive analysis based on spontaneous reports submitted to the EudraVigilance (EV) database. From 1 January to 31 December 2022, we included 111 hospitalized patients with CDI from SCCEH. Moreover, 249 individual case safety reports (ICSRs) from EVs were analyzed. According to the data collected from SCCEH, CDI was most frequently reported in patients aged 65-85 years (66.7%) and in females (55%). In total, 71.2% of all patients showed positive medical progress. Most cases were reported in the internal medicine (n = 30, 27%), general surgery (n = 26, 23.4%), and infectious disease (n = 22, 19.8%) departments. Patients were most frequently exposed to ceftriaxone (CFT) and meropenem (MER). Also, in the EV database, most CDI-related ADRs were reported for CFT, PIP/TAZ (piperacillin/tazobactam), MER, and CPX (ciprofloxacin). Understanding the association between previous antibiotic exposure and the risk of CDI may help update antibiotic stewardship protocols and reduce the incidence of CDI by lowering exposure to high-risk antibiotics.

Defined microbial communities and their soluble products protect mice from Clostridioides difficile infection

Clostridioides difficile is the leading cause of antibiotic-associated infectious diarrhea. The development of C.difficile infection is tied to perturbations of the bacterial community in the gastrointestinal tract, called the gastrointestinal microbiota. Repairing the gastrointestinal microbiota by introducing lab-designed bacterial communities, or defined microbial communities, has recently shown promise as therapeutics against C.difficile infection, however, the mechanisms of action of defined microbial communities remain unclear. Using an antibiotic- C.difficile mouse model, we report the ability of an 18-member community and a refined 4-member community to protect mice from two ribotypes of C.difficile (CD027, CD078; p < 0.05). Furthermore, bacteria-free supernatant delivered orally to mice from the 4-member community proteolyzed C.difficile toxins in vitro and protected mice from C.difficile infection in vivo (p < 0.05). This study demonstrates that bacteria-free supernatant is sufficient to protect mice from C.difficile; and could be further explored as a therapeutic strategy against C.difficile infection.

Reviewing the Clostridioides difficile Mouse Model: Insights into Infection Mechanisms

Clostridioides difficile is an anaerobic, spore-forming bacterium associated with intestinal infection, manifesting a broad spectrum of gastrointestinal symptoms, ranging from mild diarrhea to severe colitis. A primary risk factor for the development of C. difficile infection (CDI) is antibiotic exposure. Elderly and immunocompromised individuals are particularly vulnerable to CDI. A pivotal aspect for comprehending the complexities of this infection relies on the utilization of experimental models that mimic human CDI transmission, pathogenesis, and progression. These models offer invaluable insights into host-pathogen interactions and disease dynamics, and serve as essential tools for testing potential therapeutic approaches. In this review, we examine the animal model for CDI and delineate the stages of infection, with a specific focus on mice. Our objective is to offer an updated description of experimental models employed in the study of CDI, emphasizing both their strengths and limitations.

Pro-Inflammatory Cytokines Enhanced In Vitro Cytotoxic Activity of Clostridioides difficile Toxin B in Enteric Glial Cells: The Achilles Heel of Clostridioides difficile Infection?

Bacterial infections are characterized by an inflammatory response, which is essential for infection containment but is also responsible for negative effects on the host. The pathogen itself may have evolved molecular mechanisms to antagonize the antimicrobial effects of an inflammatory response and to enhance its pathogenicity using inflammatory response mediators, such as cytokines. Clostridioides difficile (C. difficile) infection (CDI) causes gastrointestinal diseases with markedly increasing global incidence and mortality rates. The main C. difficile virulence factors, toxin A and B (TcdA/TcdB), cause cytopathic/cytotoxic effects and inflammation. We previously demonstrated that TcdB induces enteric glial cell (EGC) apoptosis, which is enhanced by the pro-inflammatory cytokine tumor necrosis factor alpha plus interferon gamma (CKs). However, it is unknown whether CKs-enhanced TcdB cytotoxicity (apoptosis/necrosis) is affected by the timing of the appearance of the CKs. Thus, we simulated in vitro, in our experimental model with TcdB and EGCs, three main situations of possible interactions between TcdB and the timing of CK stimulation: before TcdB infection, concomitantly with infection, or at different times after infection and persisting over time. In these experimental conditions, which all represent situations of possible interactions between C. difficile and the timing of CK stimulation, we evaluated apoptosis, necrosis, and cell cycle phases. The CKs, in all of these conditions, enhanced TcdB cytotoxicity, which from apoptosis became necrosis when CK stimulation persisted over time, and was most relevant after 48 h of TcdB:EGCs interaction. Particularly, the enhancement of apoptosis by CKs was dependent on the TcdB dose and in a less relevant manner on the CK stimulation time, while the enhancement of necrosis occurred always independently of the TcdB dose and CK stimulation time. However, since in all conditions stimulation with CKs strongly enhanced the TcdB cytotoxicity, it always had a negative impact on C. difficile pathogenicity. This study might have important implications for the treatment of CDI.

Quality of life among older patients receiving faecal microbiota transplant for Clostridioides difficile infection

BACKGROUND

Faecal microbiota transplantation (FMT) has mainly been studied in quantitative research to investigate effect rates. However, there is a lack of qualitative studies to explore patient perspectives.

AIM

To explore perceptions of quality of life in older patients with Clostridioides difficile infection (CDI) at least 1 week after receiving FMT.

METHOD

A qualitative study examining quality of life for patients treated with FMT.

FINDINGS

Patients with a permanent or transient treatment effect experienced an increase in quality of life in the physical, psychological and social domains. However, patients who did not respond to the treatment experienced negative impacts on their psychological, physical, and social domains. Although patients found the content unappealing, none had reservations about receiving the treatment.

CONCLUSION

This study highlights the importance of considering the psychological, social and physical wellbeing of patients when assessing the efficacy of FMT as a treatment option for patients with CDI. It further emphasises the importance of health professionals identifying patients' individual ways of handling the disease and everyday life to improve their quality of life.

A Streamlined Method to Obtain Biologically Active TcdA and TcdB Toxins from Clostridioides difficile

The major virulence factors of Clostridioides difficile (C. difficile) are enterotoxins A (TcdA) and B (TcdB). The study of toxins is a crucial step in exploring the virulence of this pathogen. Currently, the toxin purification process is either laborious and time-consuming in C. difficile or performed in heterologous hosts. Therefore, we propose a streamlined method to obtain functional toxins in C. difficile. Two C. difficile strains were generated, each harboring a sequence encoding a His-tag at the 3' end of C. difficile 630∆erm tcdA or tcdB genes. Each toxin gene is expressed using the Ptet promoter, which is inducible by anhydro-tetracycline. The obtained purification yields were 0.28 mg and 0.1 mg per liter for rTcdA and rTcdB, respectively. In this study, we successfully developed a simple routine method that allows the production and purification of biologically active rTcdA and rTcdB toxins with similar activities compared to native toxins.

Multidrug-Resistant Bacteria Contaminating Plumbing Components and Sanitary Installations of Hospital Restrooms

Antimicrobial resistance (AMR) poses several issues concerning the management of hospital-acquired infections, leading to increasing morbidity and mortality rates and higher costs of care. Multidrug-resistant (MDR) bacteria can spread in the healthcare setting by different ways. The most important are direct contact transmission occurring when an individual comes into physical contact with an infected or colonized patient (which can involve healthcare workers, patients, or visitors) and indirect contact transmission occurring when a person touches contaminated objects or surfaces in the hospital environment. Furthermore, in recent years, toilets in hospital settings have been increasingly recognised as a hidden source of MDR bacteria. Different sites in restrooms, from toilets and hoppers to drains and siphons, can become contaminated with MDR bacteria that can persist there for long time periods. Therefore, shared toilets may play an important role in the transmission of nosocomial infections since they could represent a reservoir for MDR bacteria. Such pathogens can be further disseminated by bioaerosol and/or droplets potentially produced during toilet use or flushing and be transmitted by inhalation and contact with contaminated fomites. In this review, we summarize available evidence regarding the molecular features of MDR bacteria contaminating toilets of healthcare environments, with a particular focus on plumbing components and sanitary installation. The presence of bacteria with specific molecular traits in different toilet sites should be considered when adopting effective managing and containing interventions against nosocomial infections potentially due to environmental contamination. Finally, here we provide an overview of traditional and new approaches to reduce the spreading of such infections.

Fecal Microbiota Transplantation as Emerging Treatment in European Countries 2.0

Clostridioides difficile infection (CDI) is one of the most common healthcare-associated infections and one of the leading causes of morbidity and mortality in hospitalized patients in the world. Although several antibiotics effectively treat CDI, some individuals may not respond to these drugs and may be cured by transplanting stool from healthy donors. FMT has demonstrated extraordinary cure rates for the cure of CDI recurrences.Moreover, FMT has also been investigated in other disorders associated with the alteration of gut microbiota, such as inflammatory bowel disease (IBD), where the alterations of the gut microbiota ecology have been theorized to play a causative role. Although FMT is currently not recommended to cure IBD patients in clinical practice, several studies have been recently carried out with the ultimate goal to search new therapeutic options to patients.This review summarizes data on the use of FMT for the treatment of both CDI and IBD, with a special attention to highlight studies conducted in European countries.

Clostridioides difficile Infection in Hospitalized Patients-A Retrospective Epidemiological Study

Clostridioides difficile infection (CDI) is the main source of healthcare and antibiotic-associated diarrhea in hospital context and long-term care units, showing significant morbidity and mortality. This study aimed to analyze the epidemiological context, describing the severity and outcomes of this event in patients admitted to our hospital, thus confirming the changing global epidemiological trends in comparison with other cohorts. We conducted a single-center, observational, and retrospective study at the Hospital do Espírito Santo (HESE), Évora, in Portugal, analyzing the incidence of CDI in patients meeting eligibility criteria from January to December 2018. During this period, an annual incidence rate of 20.7 cases per 10,000 patients was documented. The studied population average age was 76.4 ± 12.9 years, 83.3% over 65. Most episodes were healthcare-acquired, all occurring in patients presenting multiple risk factors, with recent antibiotic consumption being the most common. Regarding severity, 23.3% of cases were classified as severe episodes. Recurrences affected 16.7% of participants, predominantly female patients over 80 years old, all of whom were healthcare-acquired. Mortality rate was disproportionately high among the older population. Our investigation documented an overall incidence rate of over 10.4-fold the number of cases identified in the year 2000 at the same hospital, more recently and drastically, in community-associated episodes.

Clostridioides difficile infection after extracorporeal membrane oxygenation support for acute myocardial infarction: a case report

Introduction

Restored cardiopulmonary function is efficiently achieved by utilizing extracorporeal membrane oxygenation (ECMO). Nevertheless, the incidence of Clostridioides difficile infection (CDI) associated with ECMO is relatively uncommon.

Case presentation

In this report, we present the case of a 59-year-old male with severe chest pain due to acute myocardial infarction, subsequently necessitating ECMO support. During the first day of hospitalization, pulmonary infections were observed, and piperacillin-tazobactam was prescribed for 7 days at low dosages. However, the patient developed severe diarrhea 4 days later. After ruling out common pathogens, we suspected the occurrence of CDI and performed genetic testing for C. difficile toxin, confirming our diagnosis. The prescription of vancomycin resulted in slight improvement, while fecal microbiota transplantation (FMT) proved to be more effective.

Conclusion

In this case, temporary application of ECMO was applied, and the anti-infective treatment relied on the use of antibiotics at short-term, low-dose, and low CDI risk. Hence, the occurrence of CDI was considered an uncommon event, which may serve as a reference for future cases.

Genomic surveillance of Clostridioides difficile transmission and virulence in a healthcare setting

Clostridioides difficile infection (CDI) is a major cause of healthcare-associated diarrhea, despite the widespread implementation of contact precautions for patients with CDI. Here, we investigate strain contamination in a hospital setting and genomic determinants of disease outcomes. Across two wards over six months, we selectively cultured C. difficile from patients (n=384) and their environments. Whole-genome sequencing (WGS) of 146 isolates revealed that most C. difficile isolates were from clade 1 (131/146, 89.7%), while only one isolate of the hypervirulent ST1 was recovered. Of culture-positive admissions (n=79), 19 (24%) of patients were colonized with toxigenic C. difficile on admission to the hospital. We defined 25 strain networks at ≤ 2 core gene SNPs; 2 of these networks contain strains from different patients. Strain networks were temporally linked (p<0.0001). To understand genomic correlates of disease, we conducted WGS on an additional cohort of C. difficile (n=102 isolates) from the same hospital and confirmed that clade 1 isolates are responsible for most CDI cases. We found that while toxigenic C. difficile isolates are associated with the presence of cdtR , nontoxigenic isolates have an increased abundance of prophages. Our pangenomic analysis of clade 1 isolates suggests that while toxin genes ( tcdABER and cdtR ) were associated with CDI symptoms, they are dispensable for patient colonization. These data indicate toxigenic and nontoxigenic C. difficile contamination persists in a hospital setting and highlight further investigation into how accessory genomic repertoires contribute to C. difficile colonization and disease.

Vancomycin vs metronidazole use for the treatment of Clostridioides difficile infection in a tertiary care hospital in Saudi Arabia

Background

The 2017 Infectious Diseases Society of America (IDSA) Clostridioides difficile infection (CDI) guidelines recommendation for oral vancomycin as preferred treatment was based on studies conducted in North America, Australia, and Europe. According to recent published data, metronidazole remains a reasonable option. No studies have been conducted in Saudi Arabia to compare prescribing patterns before and after the release of the guidelines. Due to low CDI burden in Saudi Arabia, the aim is to assess the effectiveness and outcomes of vancomycin vs metronidazole treatment options.

Methods

This was a retrospective cohort study conducted in a tertiary care hospital in Jeddah which was approved by the Institutional Review Board (IRB 2020-53). Data was collected from January 2017 to April 2020. Eligible patients were adults (>18 years old) diagnosed with CDI who either received oral metronidazole (500 mg 3 times daily) or oral vancomycin (125-500 mg 4 times daily). Patients who received a combination of treatment or who were diagnosed with fulminant CDI were excluded. Demographic data were collected. The primary outcome was to assess treatment response to initial therapy with oral metronidazole versus oral vancomycin. Secondary outcomes included assessing early treatment response, time to discharge after diagnosis, proportion of patients with a positive VRE surveillance culture within 6 months of diagnosis, 30-day recurrence and 30-day all-cause mortality. Chi-square or Fisher's exact test were used to examine differences in categorical variables while student t-test or Mann-Whitney test, were used to examine differences in continuous variables. P value < 0.05 was considered as significant.

Results

A total of 166 patients were included in the analysis. Demographic characteristics were not significantly different between the two groups. There was no difference in treatment response between vancomycin and metronidazole (96.4 % versus 94.3 %, p = 0.682). However, compared with metronidazole, vancomycin treatment was significantly associated with better early response (94.0 % versus 77.8 %, p = 0.008). Other outcomes were not significantly different between the two drug groups for time to discharge after diagnosis (P = 0.522), 30-day recurrence (P > 0.99) and 30-day all-cause mortality (P = 0.782). Of note, the vancomycin versus metronidazole use before the 2017 IDSA guidelines (26 % versus 74 %) was completely reversed after the release of the guidelines (83.3 % versus 16.7 %), p < 0.001).

Conclusion

The results of this study demonstrate that vancomycin and metronidazole have comparable outcomes in regards to treatment response for non-fulminant CDI. The study also reveals the high and quick impact of international guidelines on local prescription patterns. Further studies are needed in Saudi Arabia to guide the treatment of CDI.

Clostridioides difficile infection-associated cause-specific and all-cause mortality: a population-based cohort study

OBJECTIVES

Clostridioides difficile infection (CDI) is a common healthcare-associated infection and leading cause of gastroenteritis-related mortality worldwide. However, data on CDI-associated mortality are scarce. We aimed to examine the association between CDI and all-cause and cause-specific mortality. We additionally explored contributing causes of mortality, including recurrent CDI, hospital- or community-acquired CDI, chronic comorbidities, and age.

METHODS

This nationwide population-based cohort study (from 2006 to 2019) compared individuals with CDI with the entire Swedish background population using standardized mortality ratios. In addition, a matched-cohort design (1:10), utilizing multivariable Poisson-regression models, provided incidence rate ratios (IRRs) with 95% CIs.

RESULTS

This study included 43 150 individuals with CDI and 355 172 controls. In total, 69.7% were ≥65 years, and 54.9% were female. CDI was associated with a 3- to 7-fold increased mortality rate (IRR = 3.5, 95% CI: 3.3-3.6; standardized mortality ratio = 6.8, 95% CI: 6.7-6.9) compared with the matched controls and Swedish background population, respectively. Mortality rates were highest for hospital-acquired CDI (IRR = 2.4, 95% CI: 1.9-3.2) and during the first CDI episode (IRR = 0.2, 95% CI: 0.2-0.3 for recurrent versus first CDI). Individuals with CDI had more chronic comorbidities than controls, yet mortality remained higher among CDI cases even after adjustment and stratification for comorbidity; CDI was associated with increased mortality (IRR = 6.1, 95% CI: 5.5-6.8), particularly among those without any chronic comorbidities.

DISCUSSION

CDI was associated with elevated all-cause and cause-specific mortality, despite possible confounding by ill health. Mortality rates were consistently increased across sexes, all age groups, and comorbidity groups.

Genetic variation in the human leukocyte antigen region confers susceptibility to Clostridioides difficile infection

Clostridioides difficile (C. diff.) infection (CDI) is a leading cause of hospital acquired diarrhea in North America and Europe and a major cause of morbidity and mortality. Known risk factors do not fully explain CDI susceptibility, and genetic susceptibility is suggested by the fact that some patients with colons that are colonized with C. diff. do not develop any infection while others develop severe or recurrent infections. To identify common genetic variants associated with CDI, we performed a genome-wide association analysis in 19,861 participants (1349 cases; 18,512 controls) from the Electronic Medical Records and Genomics (eMERGE) Network. Using logistic regression, we found strong evidence for genetic variation in the DRB locus of the MHC (HLA) II region that predisposes individuals to CDI (P > 1.0 × 10-14; OR 1.56). Altered transcriptional regulation in the HLA region may play a role in conferring susceptibility to this opportunistic enteric pathogen.

Prevalence of diagnostically-discrepant Clostridioides difficile clinical specimens: insights from longitudinal surveillance

Background

Clostridioides difficile Infection (CDI) is a healthcare-associated diarrheal disease prevalent worldwide. A common diagnostic algorithm relies on a two-step protocol that employs stool enzyme immunoassays (EIAs) to detect the pathogen, and its toxins, respectively. Active CDI is deemed less likely when the Toxin EIA result is negative, even if the pathogen-specific EIA is positive for C. difficile. We recently reported, however, that low-toxin-producing C. difficile strains recovered from Toxin-negative ('discrepant') clinical stool specimens can be fully pathogenic, and cause lethality in a rodent CDI model. To document frequency of discrepant CDI specimens, and evaluate C. difficile strain diversity, we performed longitudinal surveillance at a Southern Arizona tertiary-care hospital.

Methods

Diarrheic stool specimens from patients with clinical suspicion of CDI were obtained over an eight-year period (2015-2022) from all inpatient and outpatient Units of a > 600-bed Medical Center in Southern Arizona. Clinical laboratory EIA testing identified C. difficile-containing specimens, and classified them as Toxin-positive or Toxin-negative. C. difficile isolates recovered from the stool specimens were DNA fingerprinted using an international phylogenetic lineage assignment system ("ribotyping"). For select isolates, toxin abundance in stationary phase supernatants of pure cultures was quantified via EIA.

Results

Of 8,910 diarrheic specimens that underwent diagnostic testing, 1733 (19.4%) harbored C. difficile. Our major findings were that: (1) C. difficile prevalence and phylogenetic diversity was stable over the 8-year period; (2) toxigenic C. difficile was recovered from 69% of clinically Tox-neg ('discrepant') specimens; (3) the six most prevalent USA ribotypes were recovered in significant proportions (>60%) from Tox-neg specimens; and (4) toxin-producing C. difficile recovered from discrepant specimens produced less toxin than strains of the same ribotype isolated from non-discrepant specimens.

Conclusion

Our study highlights the dominance of Toxin EIA-negative CDI specimens in a clinical setting and the high frequency of known virulent ribotypes in these specimens. Therefore, a careful reevaluation of the clinical relevance of diagnostically-discrepant specimens particularly in the context of missed CDI diagnoses and C. difficile persistence, is warranted.

Mining Autoimmune-Disorder-Linked Molecular-Mimicry Candidates in Clostridioides difficile and Prospects of Mimic-Based Vaccine Design: An In Silico Approach

Molecular mimicry, a phenomenon in which microbial or environmental antigens resemble host antigens, has been proposed as a potential trigger for autoimmune responses. In this study, we employed a bioinformatics approach to investigate the role of molecular mimicry in Clostridioides difficile-caused infections and the induction of autoimmune disorders due to this phenomenon. Comparing proteomes of host and pathogen, we identified 23 proteins that exhibited significant sequence homology and were linked to autoimmune disorders. The disorders included rheumatoid arthritis, psoriasis, Alzheimer's disease, etc., while infections included viral and bacterial infections like HIV, HCV, and tuberculosis. The structure of the homologous proteins was superposed, and RMSD was calculated to find the maximum deviation, while accounting for rigid and flexible regions. Two sequence mimics (antigenic, non-allergenic, and immunogenic) of ≥10 amino acids from these proteins were used to design a vaccine construct to explore the possibility of eliciting an immune response. Docking analysis of the top vaccine construct C2 showed favorable interactions with HLA and TLR-4 receptor, indicating potential efficacy. The B-cell and T-helper cell activity was also simulated, showing promising results for effective immunization against C. difficile infections. This study highlights the potential of C. difficile to trigger autoimmunity through molecular mimicry and vaccine design based on sequence mimics that trigger a defensive response.

Predictors of Clostridium difficile infection after stoma reversal following TaTME surgery

BACKGROUND

 The aim of this study was to determine the incidence of Clostridium Difficile infection (CDI) after stoma reversal in patients who underwent transanal Total Mesorectal Excision (TaTME) and to evaluate variables correlated with this post-operative infection.

METHODS

 Patients who underwent stoma reversal surgery following TaTME for rectal cancer between 2015 and 2023 at a high-volume Institution, were retrospectively reviewed for the post-operative occurrence of diarrhea and in-hospital CDI (positive toxin in the stools). Patients were divided into the following subgroups according to the post-operative course: Group A-no clinical symptoms; Group B-mild diarrhea (< 10 evacuations/day); Group C-severe watery diarrhea (> 10 evacuations/day) with CDI negative; and Group D-severe watery diarrhea (> 10 evacuations/day) CDI positive. Clinical and laboratory data were analyzed for their correlation with CDI. A machine learning approach was used to determine predictors of diarrhea following stoma reversal.

RESULTS

 A total of 126 patients were selected, of whom 79 were assessed as Group A, 16 Group B, 25 Group C and 6 (4.8%) Group D. Univariable analysis documented that delayed stoma reversal correlated with CDI (Group A mean interval 44.6 weeks vs. Group D 68.4 weeks, p 0.01). The machine learning analysis confirmed the delay in stoma closure as a probability factor of presenting diarrhea; also, diarrhea probability was 80.5% in males, 77.8% in patients who underwent neoadjuvant therapy, and 63.9% in patients who underwent adjuvant therapy.

CONCLUSIONS

 Stoma reversal surgery can result in moderate rate of in-hospital CDI. Time-to stoma reversal is a crucial variable significantly related with this adverse outcome.

Clostridioides difficile and colorectal cancer: a dangerous liaison

Many colorectal diseases depend on complex interactions between several pathophysiological factors, including the intestinal microbiota. In recent years, the widespread use of antibiotics has been recognized as a main cause of intestinal dysbiosis and a favouring factor for Clostridioides difficile infection. The latter, in addition, causes infectious diarrhoea, pseudomembranous colitis, and toxic megacolon by means of its toxins (A and, especially, B), is characterized by frequent relapses; thus, its persistence in a host may be long-lasting. Based on recent experimental evidence, here we analyse the possibility that, similarly to other bacteria, Clostridioides difficile may be considered a potential carcinogen for colorectal cancer.

Design of 8-mer peptides that block Clostridioides difficile toxin A in intestinal cells

Infections by Clostridioides difficile, a bacterium that targets the large intestine (colon), impact a large number of people worldwide. Bacterial colonization is mediated by two exotoxins: toxins A and B. Short peptides that can be delivered to the gut and inhibit the biocatalytic activity of these toxins represent a promising therapeutic strategy to prevent and treat C. diff. infection. We describe an approach that combines a Peptide Binding Design (PepBD) algorithm, molecular-level simulations, a rapid screening assay to evaluate peptide:toxin binding, a primary human cell-based assay, and surface plasmon resonance (SPR) measurements to develop peptide inhibitors that block Toxin A in colon epithelial cells. One peptide, SA1, is found to block TcdA toxicity in primary-derived human colon (large intestinal) epithelial cells. SA1 binds TcdA with a KD of 56.1 ± 29.8 nM as measured by surface plasmon resonance (SPR).