The standard antimicrobial therapy for Clostridioides difficile infections (CDIs) is limited to oral fidaxomicin or vancomycin, but these agents are associated with high treatment failure and recurrence rates. Clostridium butyricum had been proven effective in many kinds of gastrointestinal disease. With a less disturbed gut microbiota, we hypothesized that the properties of Clostridium butyricum Miyairi Bacteriocin (CBM-B) make it a potential therapeutic agent for treating patients with CDIs.

The inhibitory effects of CBM-B and vancomycin were compared using the kinetic time-kill assay, ex vivo co-culture model and mouse model.

Among the clinical isolates of C. difficile, the minimal inhibitory concentration (MIC) of CBM-B ranged from 0.0625 to 8 µg/ml; the MIC50 and MIC90 were 1 µg/ml and 4 µg/ml, respectively. In the mouse model infected with a RT078 and receiving CBM-B intra-rectal enema therapy, mice infected with isolates with a relative low CBM-B MICs (2 µg/ml, abbreviated as M2) revealed significant better therapeutic effect, including less loss of body weight and cecum weight, compared with those infected with isolates of relative high CBM-B MICs (4 or 8 µg/ml, abbreviated as M4 or M8) . The relative C. difficile bacterial burden in stool of mice receiving CBM-B treatment were significantly lower among mice infected with M2, compared with that infected with M4 or M8. CBMB treatment, compared with vancomycin therapy revealed less disturbance in gut microbiota.

CBM-B could be effective in the treatment of CDIs that infected with a C. difficile isolate with relatively low MICs with less disturbance in gut microbiota.

Clostridioides difficile causes debilitating colitis via secreted toxins that disrupt the intestinal barrier, and toxemia is associated with severe disease. Thus, therapies that fortify the intestinal barrier will reduce the severity of infection. Innate lymphoid cells (ILCs) are critical in the defense against acute C. difficile infection and represent a promising therapeutic target to limit disease. Here, we report that oral administration of the Toll-like receptor (TLR) 7 agonist R848 limits intestinal damage and protects mice from lethal C. difficile infection without impacting pathogen burden or altering the intestinal microbiome. R848 induced interleukin (IL)-22 secretion by ILCs, leading to STAT3 phosphorylation in the intestinal epithelium and increased stem cell proliferation. Genetic ablation of ILCs, IL-22, or epithelial-specific STAT3 abrogated R848-mediated protection. R848 reduced intestinal permeability following infection and limited systemic toxin dissemination. Combined, these data identify an immunostimulatory molecule that activates IL-22 production in ILCs to enhance host tissue defenses following C. difficile infection.

Bacterial spores pose significant risks to human health, yet the inactivation of spores is challenging due to their unique structures and chemical compositions. This study investigated the synergistic effect between surfactants and chlorine on the inactivation kinetics of Bacillus subtilis spores. Two surfactants, cocamidopropyl betaine (CAPB) and cetyltrimethylammonium chloride (CTMA) were selected to investigate chlorine disinfection in absence and presence of surfactants. The concurrent presence of both chlorine and surfactant resulted in a moderate reduction in the lag-phases for spore inactivation and negligible increase in the second-order inactivation rate constants. In contrast, when the spores were pre-exposed to surfactants, the lag-phases decreased by about 50 % for both CAPB and CTMA, and the second-order inactivation rate constants during post-chlorination remained constant for CAPB but increased by a factor of 2.3 for CTMA, compared to the control group with phosphate buffer. This synergistic effect became more pronounced with longer surfactant pre-exposure times, reaching its maximum at 3-6 h. The observed synergistic effect suggests that surfactants can potentially enhance the permeability of the coat which is the outmost layer of B. subtilis spores and a primary barrier for chemical disinfectants. Tracing a group of B. subtilis spores sequentially treated with surfactant and chlorine by atomic force microscopy, a significant decrease in compressive stiffness of the spores was observed due to exposure to surfactants, indicating alterations in the coat by surfactants. The trend in reducing compressive stiffness aligned well with the decrease of lag-phases in inactivation kinetics. Furthermore, CTMA was found to inactivate B. subtilis spores through mechanisms different from chlorine. Chlorine primarily inactivated B. subtilis spores before damaging the inner membrane of the spores which plays a crucial role in protecting the genetic material stored in the core of the spores. In comparison, CTMA damaged 22 % of the inner membrane for an inactivation efficiency of 99 %. A synergistic effect in damaging the inner membrane was observed when applying CTMA and chlorine simultaneously instead of sequentially.

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.

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.

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.

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

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.

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

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.

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.

This study investigated the effect of peroxidized lipids on piglets' growth performance, intestinal morphology, inflammatory reactions, oxidative stress in the liver, duodenum, jejunum, ileum, and colon, and ileal microbiota. Twenty piglets (Duroc × [Landrace × Yorkshire]; age = 21 d old, BW = 6.5 ± 1 kg) were randomly assigned to two groups with 10 replicates per group and one piglet per replicate. The control group was fed 6% fresh soybean oil and the peroxidized soybean oil (PSO) group fed 6% PSO. The experimental feeding period lasted 24 d. The study found no impact on ADFI, ADG and gain to feed ratio (P > 0.05). However, the PSO group increased the diarrhea index and the serum levels of lactate dehydrogenase triglycerides, cholesterol, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol (P < 0.05), along with decreased concentrations of alanine aminotransferase and blood urea nitrogen (P < 0.05). For oxidative enzymes, PSO increased the concentration of F2-isoprostane in urine (P = 0.032), malondialdehyde (MDA) in the duodenum (P = 0.001) and jejunum (P = 0.004), decreased thiobarbituric acid reactive substances (TBARS) in the liver (P = 0.001) but increased TBARS in duodenum (P = 0.001), and carbonylated proteins in the duodenum (P = 0.003). For antioxidant enzymes, PSO decreased superoxide dismutase (SOD) in the liver (P = 0.001), colon (P = 0.002), and jejunum (P = 0.015), along with glutathione peroxidase (GSH-Px) in the liver (P = 0.008) and NAD(P)H:quinone oxidoreductase 1 (NQO1) in ileum (P = 0.001). For inflammatory reactions, PSO increased interleukin (IL)-1β concentrations in the duodenum and colon, and IL-10 in the jejunum, while decreasing IL-4 concentration in the duodenum (P < 0.05). For intestinal morphology and ileal microbiota, PSO increased ileal crypt depth, while decreasing the crypt-to-villus ratio (P < 0.05). Peroxidized soybean oil increased the relative abundance of Prevotella, Clostridium_sensu_stricto_1, Clostridium_sensu_stricto_6, Pasteurella and Klebsiella (P < 0.05). In conclusion, this study revealed that PSO worsened diarrhea, increasing the ileal crypt depth and the relative abundance of harmful microbiota, and induced oxidative stress and inflammation in the intestines and liver, primarily in the jejunum and ileum.

Recurrent Clostridioides difficile infection (CDI) is primarily driven by antibiotic-induced disruption of the indigenous intestinal microbiota. Restoration of microbiota through fecal microbiota transplantation (FMT) is effective in preventing subsequent CDI, although this effect is attenuated with additional antibiotic exposure. The aim of this study was to identify the risk factors for recurrent antibiotic administration after FMT.

This is a prospective cohort of patients who were administered FMT for recurrent CDI from 1 July 2019 through 23 November 2023 across 6 institutions in the United States. Providers collected de-identified data at the time of FMT administration and in the months post-FMT administration.

The analysis included 448 patients. Risk factors for non-CDI antibiotic administration within 2 months of FMT included immunocompromised status (odds ratio [OR], 2.2 [95% confidence interval {CI}, 1.1-4.4]; P = .02), >3 non-CDI antibiotic courses pre-FMT (OR, 3.1 [95% CI, 1.4-6.8]; P = .006), and prior hospitalization for CDI (OR, 2.0 [95% CI, 1.1-3.8]; P = .02). The most common indications for non-CDI antibiotic administration post-FMT were urinary tract infections, respiratory infections, and procedure prophylaxis.

Non-CDI antibiotic exposure significantly increases the risk of CDI recurrence post-FMT. Risk factors for non-CDI antibiotic administration within 2 months of FMT include immunocompromised status, multiple prior non-CDI antibiotics, and prior hospitalization for CDI. These individuals may benefit from additional or modified recurrent CDI prevention strategies.

Clostridium difficile (C. difficile) stands as a primary cause of health-care-associated colitis in adults; however, extraintestinal manifestations of C. difficile, particularly bacteremia, are exceptionally rare. In this report, we document a case of an elderly male with multiple comorbidities who presented with an acute onset of fever. Diagnostic testing revealed the presence of concurrent bacteremia involving C. difficile and Klebsiella pneumonia. The multilocus sequence typing analysis identified this C. difficile strain as ST81. After receiving a combination treatment of vancomycin and biapenem, the patient successfully recovered and was subsequently discharged. This case report elucidates the clinical presentation and treatment strategies for C. difficile ST81 bacteremia, underscoring the critical need for heightened monitoring of extraintestinal infections in high-risk patients.

Plants are composed of diverse secondary metabolites (PSMs), which are widely associated with human health. Whether and how the gut microbiome mediates such impacts of PSMs is poorly understood. Here, we show that discrete dietary and medicinal phenolic glycosides, abundant health-associated PSMs, are utilized by distinct members of the human gut microbiome. Within the Bacteroides, the predominant gram-negative bacteria of the Western human gut, we reveal a specialized multi-enzyme system dedicated to the processing of distinct glycosides based on structural differences in phenolic moieties. This Bacteroides metabolic system liberates chemically distinct aglycones with diverse biological functions, such as colonization resistance against the gut pathogen Clostridioides difficile via anti-microbial activation of polydatin to the stilbene resveratrol and intestinal homeostasis via activation of salicin to the immunoregulatory aglycone saligenin. Together, our results demonstrate generation of biological diversity of phenolic aglycone "effector" functions by a distinct gut-microbiome-encoded PSM-processing system.

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.

Asymptomatic patients colonized with toxigenic Clostridioides difficile are at risk of progressing to C. difficile infection (CDI), but risk factors associated with progression are poorly understood. The objectives of this study were to estimate the incidence and identify risk factors to progression of hospital-onset CDI (HO-CDI) among colonized patients.

This was a nested case-control study at an academic medical center including adult patients colonized with toxigenic C. difficile, detected via polymerase chain reaction (PCR) on a rectal swab collected on admission from 2017 to 2020. Patients with prior CDI or symptoms on admission, neutropenia, prior rectal surgery, or hospitalization less than 24 hours were excluded. Colonized patients that developed HO-CDI were matched 1:3 to colonized patients who did not based on PCR test date. Bivariate and multivariable-adjusted Cox regression analyses were used to identify risk factors.

Of 2,150 colonized patients, 109 developed HO-CDI, with an incidence of 5.1%. After exclusions, 321 patients (69 with HO-CDI) were included, with an estimated incidence of 4.2%. Risk factors included cirrhosis (aHR 1.94), ICU admission (aHR 1.76), malignancy (aHR 1.88), and hospitalization within six months (aHR 1.6). Prior antibiotic exposure in the past three months (aHR 2.14) and receipt of at-risk antibiotics were also identified as potential risk factors (aHR 2.17).

Progression to HO-CDI among colonized patients was not uncommon. This study highlights key risk factors associated with progression, underscoring the importance of enhanced monitoring and prevention efforts tailored to high-risk populations to mitigate HO-CDI.

Clostridioides difficile has been recognized as an important nosocomial pathogen that causes diarrheal disease as a consequence of antibiotic exposure and costs the healthcare system billions of dollars every year. C. difficile enters the host gut as dormant spores, germinates into vegetative cells, colonizes the gut, and produces toxins TcdA and/or TcdB, leading to diarrhea and inflammation. Spores are the primary transmission vehicle, while the toxins A and B directly contribute to the disease. Thus, toxin production and sporulation are the key traits that determine the success of C. difficile as a pathogen. Both toxins and spores are produced during the late stationary phase in response to various stimuli. This review provides a comprehensive analysis of the current knowledge on the molecular mechanisms, highlighting the regulatory pathways that interconnect toxin gene expression and sporulation in C. difficile. The roles of carbohydrates, amino acids and other nutrients and signals, in modulating these virulence traits through global regulatory networks are discussed. Understanding the links within the gene regulatory network is crucial for developing effective therapeutic strategies against C. difficile infections, potentially leading to targeted interventions that disrupt the co-regulation of toxin production and sporulation.

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.

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.

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.

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.

Clostridioides difficile infection is a major health threat. Healthcare institutions have strong medical and financial incentives to keep infections under control. Blanket testing at admission is in general not recommended, and current predictive models either used moderate sample sizes, over-inflated the number of covariates, or chose non-interpretable algorithms. We aim to develop models using patient data to predict positive Clostridioides difficile test results with discrimination performance, interpretable results, and a reasonable number of covariates that reflect health over a long-time span.

We processed records from 157,493 University of California San Diego Health patients seen between January 01, 2016-July 03, 2019 with at least 6 months of medication history, excluding pregnant women, patients under 18, and prisoners. Three models (Logistic Regression, Random Forest, and Ensemble) were constructed using hyper-parameters selected through 10-fold cross-validation. Model performance was measured by the Area Under the Receiver Operating Characteristic Curve (AUROC). The model coefficients' odds ratios and p-values were calculated for the Logistic Regression model, as were Gini indices for Random Forest. Decision boundary analysis was conducted using pair-wise false positive and false negative cases each model would predict at a specific threshold.

Logistic Regression, Random Forest, and Ensemble models yielded test AUROCs of 0.839, 0.851, and 0.866, respectively. Significant covariates that may affect risk include age, immuno-compromised treatments, past antibiotic uses, and some medications for the gastrointestinal tract.

The models achieve high discrimination performance (AUROC >0.83). There is a general consensus among different analysis approaches regarding predictors that impact patients' chances of having a positive test, which may influence Clostridioides difficile risk, including features clinically proven to increase susceptibility. These human-interpretable models can help distinguish significant predictors that affect a patient's chance of testing positive, which may influence their Clostridioides difficile risk.

Clostridioides difficile infection is the leading cause of antibiotic-associated, hospital-acquired diarrhea in the USA; the pathology of which is mediated by toxins. The presence of a toxin known as the C. difficile Transferase (CDT) in some clinical isolates is linked to severe symptoms including increased incidence of reinfection and higher rates of mortality. Despite its apparent importance to C. difficile pathology, a mechanistic model of how CDT intoxicates cells remains incomplete. Here, we describe a motif composed of acidic and basic residues (the KDKEK motif) that is essential for toxin function. Using Cryogenic Electron Microscopy (Cryo-EM), we highlight an orientation of the KDKEK motif wherein the acidic residues engage structures thought to play an important role during toxin delivery. We thus present a model wherein these interactions prime CDT for entry into host cells. We expect that this model can be extrapolated to other bacterial toxins to understand how they enter cells.IMPORTANCEClostridioides difficile is the leading cause of hospital-acquired infectious diarrhea in the USA. The pathology that accompanies infection is triggered by toxins produced by the bacterium. One of these, the C. difficile Transferase (CDT), has been associated with poorer patient outcomes, although a direct connection to CDT activity has remained elusive. Herein, we present new insight into the mechanism of CDT intoxication and define two regions of the toxin as important for its activity. Moreover, we have generated mutants of CDT that retain the ability to assemble but can no longer intoxicate host cells. In the future, we expect these mutants will serve as valuable tools to help elucidate the role of CDT during infection.

Antibiotics are fundamental in sepsis management; however, the optimal empirical treatment remains debated. Despite anaerobes rarely being the causative pathogen of sepsis, antibiotics targeting them are frequently used, which might lead to unintended consequences. Multiple studies have shown that depletion of commensal anaerobic gut microbes by anti-anaerobic antibiotics influences systemic immunity and is associated with increased mortality in patients with sepsis. However, this knowledge has not yet been translated into clinical practice. When considering empirical coverage of anaerobic pathogens in sepsis, most physicians advocate for a better-safe-than-sorry approach. In this Viewpoint, we argue that anti-anaerobic antibiotics could often result in being sorry rather than safe. We provide an overview of the limited necessity of anaerobic coverage and the potential detrimental effects of anaerobic depletion in sepsis. We aim to raise anaerobic awareness to reduce the unnecessary use of anti-anaerobic antibiotics in empirical sepsis treatment and improve patient outcomes.

Clostridioides difficile infection (CDI) is the most common nosocomial infection in the US. CDI has become a growing concern due to C. difficile's resistance to several antibiotics, including cephalosporins. Furthermore, patients administered cephalosporins are at higher risk of contracting CDI. Cephalosporins are β-lactam antibiotics, which prevent bacterial cell wall synthesis by inhibiting penicillin-binding proteins (PBPs). β-lactam-resistant bacteria evade these antibiotics by producing β-lactamases or by harboring low-affinity PBPs. A genomic analysis of C. difficile strain 630 identified 31 putative β-lactam resistance genes. Upon cefoxitin exposure, few C. difficile strain 630 putative antibiotic-resistant genes were overexpressed. Most notably, the β-lactamase blaCDD gene was upregulated approximately 600-fold, as previously reported. Deletion of the blaCDD locus did not change in cephalosporin susceptibility. Deletion of the second most upregulated gene, the PBP vanY, was also ineffective at decreasing cephalosporin resistance. Cefoxitin exposure of the C. difficile strain 630ΔblaCDD mutant did not increase upregulation of other putative antibiotic resistance genes compared to wildtype C. difficile strain 630. Transcriptomic analyses of wildtype C. difficile strain 630 exposed to cephradine, cefoxitin, ceftazidime, or cefepime revealed the shared upregulation of a putative heterodimeric ABC transporter encoded by loci CD630_04590 (ABC transporter ATP-binding protein) and CD630_04600 (ABC transporter permease). These genes are genomically located directly downstream of blaCDD (CD630_04580). The deletion mutant CD630_04600 remained resistant to a number of antibiotics. Thus, even though blaCDD, CD630_04590, and CD630_04600 are all upregulated when exposed to cephalosporins, they do not seem to be involved in antibiotic resistance in C. difficile strain 630.

Health claims data are a valuable resource for health services research, enabling analysis of the costs of hospitalizations, outpatient visits, procedures, and medications, and providing an improved understanding of the economic burden and underlying cost drivers for a given health condition. Since no recent data were available from Germany on the medical costs and clinical outcomes of Clostridioides difficile infections (CDI), this study assessed the economic burden of CDI and all-cause mortality in adults in Germany.

A retrospective cohort study was conducted using a large, anonymized administrative health claims research database from Germany from which an age- and sex-representative sample of 4 million insured persons covered by approximately 60 statutory health insurances was extracted. Propensity score matching was conducted on age, sex, comorbidities, and antibiotic use to identify four matched controls (i.e., patients without CDI) for every eligible adult patient with CDI (i.e., case) in the study cohort. Costs, healthcare resource utilization, and CDI-attributable all-cause mortality were assessed.

Overall, there were 15,342 CDI cases in the study cohort. One-year mortality in CDI cases (45.7%) was more than fourfold that of matched non-CDI controls (11.0%). In the year following the index date, average mortality-adjusted medical costs per person-time for CDI cases were almost fivefold that of matched non-CDI controls, representing a cost difference of €31,459, mainly driven by inpatient treatment. Overall excess costs for CDI cases were estimated at approximately €1.6 billion within 1 year after diagnosis.

CDI in Germany is associated with a high clinical and economic burden, including significantly higher mortality, costs, and healthcare resource utilization, in patients with CDI versus their matched patients without CDI. This has important implications for patients, healthcare providers, and the healthcare system.

Several studies revealed the beneficial effects of probiotics against the incidence of antibiotic-associated diarrhea of hospitalized patients but it is rarely to assess the nutrition status. This study investigated the effects of probiotics in elderly hospitalized tube-fed patients with antibiotics use and is the first study that concerns the nutritional status among these patients.

Elderly hospitalized tube-fed patients who were using antibiotics were recruited. Probiotics were given within 48 h after their first antibiotic therapy, and then twice daily 2 h after consuming antibiotics and a meal; the probiotics were continued to use for an additional 7 days after completion of antibiotics therapy. Anthropometric data, laboratory data, medication records, nutritional status, nutrition intake and data on stool form were collected.

Twenty-nine patients served as probiotic group. 11 patients completed the study in both groups. In probiotic group, the stool form was found to exhibit no significant differences between the beginning and end of antibiotics therapy (5.5 ± 0.8 vs 5.1 ± 1.1, p = 0.21), but the stool frequency significantly decreased (2.0 ± 1.0 vs 1.6 ± 0.7, p = 0.05). In control group, the stool form between the beginning and end of antibiotics therapy exhibited significant improvement (5.6 ± 1.4 vs 4.5 ± 1.4, p = 0.01), but not in the frequency (2.7 ± 2.1 vs 2.4 ± 1.5, p = 0.1). The initial NRS 2002 score of the probiotic and control groups were similar. (3.6 ± 1.7 vs 3.7 ± 1.8, p = 1.00), and their nutrition status both significantly improved during the last visit before discharged (2.6 ± 0.9 vs 2.9 ± 1.3).

Probiotic supplementation in elderly hospitalized tube-fed patients significantly reduced stool frequency during antibiotic treatment. Improvements in stool form were observed only during the follow-up period. Nutritional status remained stable, with patients' nutritional needs adequately met throughout the study.

Clostridioides difficile infection (CDI) causes substantial mortality and healthcare burden. We assessed the detoxified toxin-A/B PF-06425090 vaccine for primary CDI prevention.

This phase 3 observer-blinded study randomized (1:1) ≥50-year-olds at increased CDI risk (N = 17 535) to receive 3 PF-06425090 or placebo doses (0, 1, and 6 months). Primary end points were first CDI episode (≥3 unformed stools within 24 hours; central laboratory-confirmed toxin A/B positive) ≥14 days post-dose 3 (PD3; first primary) and post-dose 2 (PD2; second primary). CDI duration, need for CDI-related medical attention (secondary end points), and antibiotic use (post hoc analysis) PD3 were evaluated. Tolerability and safety were assessed.

The primary end point was not met (17 PF-06425090 and 25 placebo recipients had first CDI episode ≥14 days PD3 [vaccine efficacy (VE) = 31.0% (96.4% confidence interval [CI], -38.7% to 66.6%)]; 24 PF-06425090 and 34 placebo recipients had first CDI episode ≥14 days PD2 [VE = 28.6% (96.4% CI, -28.4% to 61.0%)]. Median CDI duration was lower with PF-06425090 (1 day) versus placebo (4 days; 2-sided nominal P = .02). Of participants with first CDI episode, 0 PF-06425090 and 11 placebo recipients sought CDI-related medical attention (post hoc analysis estimated VE = 100%; 95% CI, 59.6% to 100.0%) and 0 PF-06425090 and 10 placebo recipients required antibiotic treatment (VE = 100%; 95% CI, 54.8% to 100.0%). Local reactions were more frequent in PF-06425090 recipients, and systemic events were generally similar between groups; most were mild to moderate. Adverse event rates were similar between groups.

Three PF-06425090 doses were safe and well tolerated. Although the primary end point was not met, PF-06425090 reduced symptom duration, CDI that required medical attention, and CDI-directed antibiotic treatment, highlighting its potential to reduce CDI-associated healthcare burden.

NCT03090191.

Clostridioides difficile is a major cause of nosocomial infections, often associated with individuals who have gut dysbiosis from previous antibiotic therapies. C. difficile infections (CDI) have a high recurrence rate and impose significant financial and mortality burdens on the healthcare system. Therefore, novel anti-C. difficile drugs are urgently needed to treat and reduce the severity and recurrence of infection. In this study, we screened a library of 618 antiviral drugs to identify a potential candidate for repurposing as novel anti-C. difficile therapeutics. Following our preliminary screening, we identified 9 novel compounds that inhibited C. difficile at a concentration of 16 μM or lower. Among these, 4 antiviral compounds demonstrated the most potent anti-C. difficile activity against a panel of 15 C. difficile isolates, with minimum inhibitory concentrations (MICs) comparable to the drug of choice, vancomycin. These include rottlerin (MIC50 = 0.25 μg/mL), α-mangostin (MIC50 = 1 μg/mL), dryocrassin ABBA (MIC50 = 1 μg/mL), and obefazimod (MIC50 = 4 μg/mL). All exhibited minimal to no activity against representative members of the human gut microbiota. Interestingly, α-mangostin, a natural xanthone derived from the mangosteen fruit, exhibited strong bactericidal action, clearing a high inoculum of C. difficile in less than an hour. All other drugs exhibited bacteriostatic activity. Given their characteristics, these compounds show great promise as novel treatments for CDI.

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.

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.

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).

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.

Antibiotic treatment is a well-known risk factor for Clostridioides difficile infection (CDI). The time from start of antibiotic exposure to onset of CDI for different antibiotics is sparsely studied. CDI with onset in the community is often treatable without in-hospital care while CDI patients treated in hospital need isolation, resulting in higher costs and infection control measures.

To determine the time from start of antibiotic exposure to onset of healthcare facility-associated CDI for different antibiotics.

Time between antibiotic exposure and disease onset was evaluated retrospectively with chart reading in a two-centre Swedish setting. A case was attributed to an antibiotic group if this represented more than 2/3 of total antibiotic exposure 30 days before onset of CDI.

Cephalosporins caused CDI faster (mean 7.6 days), and more often during ongoing antibiotic therapy (81% of the cases) than any other antibiotic group. All other common agents had between 2-3 times longer period between start of exposure to onset of CDI (quinolones more than 3 times).

The time gap between antibiotic exposure and onset of CDI is markedly different between different antibiotics. Decreased cephalosporin use could delay onset of healthcare facility-associated CDI and limit infections with onset within the hospital. This might decrease costs for inpatient care, need of infection control measures and shortage of beds in the hospital.

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

We investigated the intra-hospital distribution of C. difficile strains by whole-genome sequencing (WGS) of isolates collected in 2022 at the University Hospital Centre (UHC) Zagreb. In total, 103 patients with first-episode CDI in 2022 at UHC Zagreb were included, based on the screening stool antigen test for GDH (RidaQuick CD GDH; R-Biopharm AG, Germany), confirmed by Eazyplex C. difficile assays (Eazyplex CD assay; AmplexDiagnostics GmbH, Germany) specific for A, B, and binary toxins. Demographic and clinical data were retrospectively analyzed from electronic medical records. All samples were subjected to WGS analysis. Genetic clusters were formed from isolates with no more than six allelic differences according to core genome MLST. We identified six clusters containing 2-59 isolates with 15 singletons and 30 instances of possible intra-hospital transmission, mostly in the COVID-19 ward. WGS analysis proved useful in identifying clusters of isolates connecting various patient wards with possible transmission routes in the hospital setting. It could be used to support local and national surveillance of CDI infections and their transmission pathways.

The zebrafish (Danio rerio) has emerged as a valuable model for studying host-pathogen interactions due to its unique combination of characteristics. These include extensive sequence and functional conservation with the human genome, optical transparency in larvae that allows for high-resolution visualization of host cell-microbe interactions, a fully sequenced and annotated genome, advanced forward and reverse genetic tools, and suitability for chemical screening studies. Despite anatomical differences with humans, the zebrafish model has proven instrumental in investigating immune responses and human infectious diseases. Notably, zebrafish larvae rely exclusively on innate immune responses during the early stages of development, as the adaptive immune system becomes fully functional only after 4-6 weeks post-fertilization. This window provides a unique opportunity to isolate and examine infection and inflammation mechanisms driven by the innate immune response without the confounding effects of adaptive immunity. In this review, we highlight the strengths and limitations of using zebrafish as a powerful vertebrate model to study innate immune responses in infectious diseases. We will particularly focus on host-pathogen interactions in human infections caused by various bacteria (Clostridioides difficile, Staphylococcus aureus, and Pseudomonas aeruginosa), viruses (herpes simplex virus 1, SARS-CoV-2), and fungi (Aspergillus fumigatus and Candida albicans).

Infectious diseases in older adults present a significant challenge to the healthcare system, marked by increased morbidity, mortality, and rising costs of care. Age-related changes (ARCs) in the immune system, including immunosenescence and inflammaging, contribute to heightened susceptibility to severe infections and reduced vaccine responsiveness. Additionally, alterations in the normal microbial flora due to aging and factors such as antibiotic therapy predispose older individuals to infections and age-related diseases. Changes in body composition also affect the pharmacokinetics and pharmacodynamics of drugs, complicating the management of antibiotics and leading to potential overdoses, adverse drug reactions, or underdoses that foster antibiotic resistance. The inappropriate use of antibiotics has exacerbated the emergence of multidrug-resistant pathogens, posing a critical global concern. This narrative review provides an overview of immunosenescence and inflammaging and focuses on three major infectious diseases affecting older adults: bacterial pneumonia, urinary tract infections, and Clostridium difficile infections. Through this exploration, we aim to highlight the need for targeted approaches in managing infectious diseases in the aging population.

This study aims to outline Clostridioides difficile infection (CDI) trends and outcomes in Mexican healthcare facilities during the COVID-19 pandemic.

Observational study of case series.

Sixteen public hospitals and private academic healthcare institutions across eight states in Mexico from January 2016 to December 2022.

CDI patients.

Demographic, clinical, and laboratory data of CDI patients were obtained from clinical records. Cases were classified as community or healthcare-associated infections, with incidence rates calculated as cases per 10,000 patient days. Risk factors for 30-day all-cause mortality were analyzed by multivariate logistic regression.

We identified 2,356 CDI cases: 2,118 (90%) were healthcare-associated, and 232 (10%) were community-associated. Common comorbidities included hypertension, diabetes, and cancer. Previous high use of proton-pump inhibitors, steroids, and antibiotics was observed. Recurrent infection occurred in 112 (5%) patients, and 30-day mortality in 371 (16%). Risk factors associated with death were a high Charlson score, prior use of steroids, concomitant use of antibiotics, leukopenia, leukocytosis, elevated serum creatine, hypoalbuminemia, septic shock or abdominal sepsis, and SARS-CoV-2 coinfection. The healthcare-associated CDI incidence remained stable at 4.78 cases per 10,000 patient days during the pre-and pandemic periods. However, the incidence was higher in public hospitals.

Our study underscores the need for routine epidemiology surveillance and standardized CDI classification protocols in Mexican institutions. Though CDI rates in our country align with those in some European countries, disparities between public and private healthcare sectors emphasize the importance of targeted interventions.

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.

The incidence of Clostridioides difficile infection (CDI) in inflammatory bowel disease (IBD) is rising and associated with adverse outcomes. Optimal treatment for CDI in IBD remains unknown, with various organisations suggesting vancomycin as first-line therapy.

To compare treatment outcomes for metronidazole versus vancomycin in mild to moderate CDI in IBD.

A retrospective analysis of IBD patients with CDI between January 2015 and December 2019 was conducted. Laboratory data and clinical outcomes were examined.

Forty-seven discrete episodes of CDI in 34 patients occurred during the study period. Fifty-three per cent (18) had Crohn's disease, 44% (15) ulcerative colitis and 3% (1) IBD unclassified. Six per cent (3/47) of CDI cases were severe and excluded. In 68% (30/44) of mild to moderate CDI, metronidazole was prescribed, with treatment failure in 20% (6/30), CDI recurrence in 13% (4/30) and 20% (6/30) experiencing a further CDI episode. Comparatively, vancomycin was prescribed in 23% (10/44) without any treatment failures; however, 10% (1/10) had CDI recurrence and 40% (4/10) experienced another CDI episode. No statistically significant difference was noted between metronidazole and vancomycin therapy for treatment failure (P = 0.31), CDI recurrence (P = 1.0) or further CDI episodes (P = 0.23). Proton-pump inhibitor therapy was the only risk factor associated with a higher rate of the composite outcome and remained significant on multivariate logistic regression (odds ratio 12.99 (95% confidence interval = 1.21-139.97), P = 0.03).

Metronidazole compared to vancomycin for treatment of mild to moderate CDI in IBD is effective however may be associated with higher rates of treatment failure.

Toxins TcdA and TcdB are the main virulence factors of Clostridioides difficile, a leading cause of hospital-acquired diarrhea. Despite their importance, there is a significant knowledge gap of druggable targets for inhibiting toxin production. To address this, we screened nonantibiotic phytochemicals to identify potential chemical genetic probes to discover antivirulence drug targets. This led to the identification of 18β-glycyrrhetinic acid (enoxolone), a licorice metabolite, as an inhibitor of TcdA and TcdB biosynthesis. Using affinity-based proteomics, potential targets were identified as ATP synthase subunit alpha (AtpA) and adenine deaminase (Ade, which catalyzes conversion of adenine to hypoxanthine in the purine salvage pathway). To validate these targets, a multifaceted approach was adopted. Gene silencing of ade and atpA inhibited toxin biosynthesis, while surface plasmon resonance and isothermal titration calorimetry molecular interaction analyses revealed direct binding of enoxolone to Ade. Metabolomics demonstrated enoxolone induced the accumulation of adenosine, while depleting hypoxanthine and ATP in C. difficile. Transcriptomics further revealed enoxolone dysregulated phosphate uptake genes, which correlated with reduced cellular phosphate levels. These findings suggest that enoxolone's cellular action is multitargeted. Accordingly, supplementation with both hypoxanthine and triethyl phosphate, a phosphate source, was required to fully restore toxin production in the presence of enoxolone. In conclusion, through the characterization of enoxolone, we identified promising antivirulence targets that interfere with nucleotide salvage and ATP synthesis, which may also block toxin biosynthesis.

SUMMARYHealthcare-associated infections (HAIs) represent a burden for public health with a high prevalence and high death rates associated with them. Pathogens with a high potential for antimicrobial resistance, such as ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) and Clostridioides difficile, are responsible for most HAIs. Despite the implementation of infection prevention and control intervention, globally, HAIs prevalence is stable and they are mainly due to endogenous pathogens. It is undeniable that complementary to infection prevention and control measures, prophylactic approaches by active or passive immunization are needed. Specific groups at-risk (elderly people, chronic condition as immunocompromised) and also healthcare workers are key targets. Medical procedures and specific interventions are known to be at risk of HAIs, in addition to hospital environmental exposure. Vaccines or monoclonal antibodies can be seen as attractive preventive approaches for HAIs. In this review, we present an overview of the vaccines and monoclonal antibodies in clinical development for prevention of the major bacterial HAIs pathogens. Based on the current state of knowledge, we look at the challenges and future perspectives to improve prevention by these means.

Divergent total syntheses of binding pocket and peripherally modified tetrachlorovancomycins, a non-native synthetic glycopeptide, and their evaluation are disclosed. Central to the approach is the synthesis of a single late-stage intermediate that bears a residue 4 thioamide ([Ψ[C(═S)NH]Tpg4]tetrachlorovancomycin (3), LLS 15 steps, 14% overall) as a precursor to either of two key pocket modifications and their pairing with any combination of two peripheral modifications conducted without protecting groups. A stereochemical simplification achieved by the addition of two aryl chlorides removes two synthetically challenging atropisomer centers in native glycopeptides and streamlines the synthesis. Key features include in a convergent epimerization-free thioacylation of the AB ring system amine with an N-thioacylbenzotriazolyl DE tetrapeptide (85%) followed by simultaneous room-temperature SNAr macrocyclizations of the CD and DE ring systems (96%). The approach provided 3 from which [Ψ[C(═N)NH]Tpg4]tetrachlorovancomycin (4) and [Ψ(CH2NH)Tpg4]tetrachlorovancomycin (5) were prepared in a single-step and bear binding pocket modifications that convey dual d-Ala-d-Ala/d-Lac ligand binding to overcome vancomycin resistance. The newest maxamycin members are disclosed, bearing two additional peripheral modifications that introduce two independent synergistic MOAs that do not rely on native ligand binding for activity. Ligand binding properties of pocket-modified tetrachlorovancomycins 3-5, antibacterial activity of a key compound series, and PK assessments of two tetrachloromaxamycins are reported.

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

Data on short courses of antibiotic therapy for Enterobacterales bacteremia in high-risk neutropenic patients are limited. The aim of the study was to describe and compare the frequency of bacteremia relapse, 30-day overall and infection-related mortality, Clostridiodes difficile infection and length of hospital stay since bacteremia among those who received antibiotic therapy for 7 or 14 days.

This is a multicenter, prospective, observational cohort study in adult high-risk neutropenic patients with hematologic malignancies or hematopoietic stem cell transplant and monomicrobial Enterobacterales bacteremia. They received appropriate empirical antibiotic therapy, had a clinical response within 7 days, and infection source control. Clinical, epidemiological and outcomes variables were compared based on 7 or 14 days of AT.

Two hundred patients were included (100, 7-day antibiotic therapy; 100, 14-day antibiotic therapy). Escherichia coli was the pathogen most frequently isolated (47.5%), followed by Klebsiella sp. (40.5%). Among those patients that received 7-day vs. 14-day antibiotic course, a clinical source of bacteremia was found in 54% vs. 57% (p = 0.66), multidrug-resistant Enterobacterales isolates in 28% vs. 30% (p = 0.75), and 40% vs. 47% (p = 0.31) received combined empirical antibiotic therapy. Overall mortality was 3% vs. 1% (p = 0.62), in no case related to infection; bacteremia relapse was 7% vs. 2% (p = 0.17), and length of hospital stay since bacteremia had a median of 9 days (IQR: 7-15) vs. 14 days (IQR: 13-22) (p =  < 0.001).

These data suggest that seven-day antibiotic therapy might be adequate for patients with high-risk neutropenia and Enterobacterales bacteremia, who receive appropriate empirical therapy, with clinical response and infection source control.

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

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

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

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

Clostridioides difficile is a spore-forming pathogen and the most common cause of healthcare-associated diarrhea and colitis in the United States. Besides producing the main virulence factors, toxin A (TcdA) and toxin B (TcdB), many of the common clinical strains encode the C. difficile transferase (CDT) binary toxin. The role of CDT in the context of C. difficile infection (CDI) is poorly understood. Inflammation is a hallmark of CDI and multiple mechanisms of inflammasome activation have been reported for TcdA, TcdB, and the organism. Some studies have suggested that CDT contributes to this inflammation through a TLR2-dependent priming mechanism that leads to the suppression of protective eosinophils. Here, we show that CDT does not prime but instead activates the inflammasome in bone marrow-derived dendritic cells (BMDCs). In bone marrow-derived macrophages (BMDMs), the cell binding and pore-forming component of the toxin, CDTb, alone activates the inflammasome and is dependent on K+ efflux. The activation is not observed in the presence of CDTa and is not observed in BMDMs derived from Nlrp3-/- mice suggesting the involvement of the NLRP3 inflammasome. However, we did not observe evidence of CDT-dependent inflammasome priming or activation in vivo. Mice were infected with R20291 and an isogenic CRISPR/Cas9-generated R20291 ΔcdtB strain of C. difficile. While CDT contributes to increased weight loss and cecal edema at 2 days post infection, the relative levels of inflammasome-associated cytokines, IL-1β and IL-18, in the cecum and distal colon are unchanged. We also saw CDT-dependent weightloss in Nlrp3-/- mice, suggesting that the increased weightloss associated with the presence of CDT is not a result of NLRP3-dependent inflammasome activation. This study highlights the importance of studying gene deletions in the context of otherwise fully isogenic strains and the challenge of translating toxin-specific cellular responses into a physiological context, especially when multiple toxins are acting at the same time.

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

Clostridioides difficile infection (CDI) represents a prevalent and potentially severe health concern linked to the usage of broad-spectrum antibiotics. The aim of this study was to evaluate a new lyophilized product based on human fecal microbiota for transplant, including cost-benefit analysis in the treatment of recurrent or refractory CDI.

The product for fecal microbiota transplant was obtained from two donors. Microbiological, viability, and genomic analysis were evaluated. After validation, a clinical pilot study including recurrent or refractory CDI with 24 patients was performed. Clinical response and 4-week recurrence were the outcome. Cost-benefit analysis compared the fecal microbiota transplant with conventional retreatment with vancomycin or metronidazole.

The microbiota for transplant presented significant bacterial viability, with and adequate balance of Firmicutes and Bacteroidetes. The clinical response with the microbiota transplant was 92%. In financial terms, estimated expenditure for CDI solely related to recurrence, based on stochastic modeling, totals USD 222.8 million per year in Brazil.

The lyophilized human fecal microbiota for transplant is safe and can be an important step for a new product with low cost, even with genomic sequencing. Fecal microbiota transplantation emerges as a more cost-effective alternative compared to antimicrobials in the retreatment of CDI.