Background/Objective: Clostridioides difficile infection (CDI) is a common healthcare-associated ailment, presenting major health and economic challenges, especially for the elderly. Despite its prevalence, comprehensive data about CDI\'s impact on the elderly are limited. Methods: This study used the Global Burden of Disease Study 2019 data to analyze CDI trends from 2000 to 2019, considering factors like sex, region, and sociodemographic index (SDI). Results: This study revealed that CDI caused approximately 18,181 deaths and 252,709 disability-adjusted life years (DALYs) among the elderly worldwide. The Americas showed the highest CDI burden, while the Eastern Mediterranean saw the steepest rate increase from 2000 to 2019. Regions with a high SDI also displayed substantial CDI impact. Conclusions: The escalating burden of CDI in the elderly, especially in high-SDI areas and the Americas, emphasizes an urgent need for targeted public health strategies.

The presence of potentially pathogenic bacteria on veterinary clinic surfaces may be problematic. In this study, we collected swab samples (Fisherbrand, double transport swabs with Stuart\'s liquid medium) and water samples from five veterinary rehabilitation clinics. Swabs and water samples were transported to a microbiology lab for processing. At the lab, swabs were used to inoculate Hardy\'s Cdiff Banana Broth (for Clostridium difficile [Cdiff]) and five different types of bacterial growth media, including Hardy CHROM MRSA agar (methicillin-resistant Staphylococcus aureus [MRSA] and S. pseudintermedius [SIM]), mannitol salt agar (S. aureus [SA]), eosin methylene blue agar (enterics [ENT]), Pseudomonas isolation agar (Pseudomonas spp. [PS]), and tryptic soy agar [TSA] (non-specific). The most prominent presumptive species cultured was Cdiff (on nearly 55% of swabs). Bacillus spp. and enteric bacteria were encountered on nearly 35% of swabs, with MRSA and SIM on just over 10% of swabs. The most contaminated sample site was harnesses/life jackets used with the underwater treadmill (33% of swabs). The underwater treadmill water had total bacterial counts from 1,600 to 2,800 cfu/mL. Of all presumptive bacterial species detected, SIM tends to be more pathogenic for dogs. Targeted cleaning/disinfecting in these clinics could help reduce risks for both animals and caregivers utilizing these clinics.

In contrast to the epidemiology 10 years earlier at our hospital when the epidemic restriction endonuclease analysis (REA) group strain BI accounted for 72% of Clostridioides difficile isolates recovered from first-episode C. difficile infection (CDI) cases, BI represented 19% of first-episode CDI isolates in 2013-2015. Two additional REA group strains accounted for 31% of isolates (Y, 16%; DH, 12%). High-level resistance to fluoroquinolones and azithromycin was more common among BI isolates than among DH, Y, and non-BI/DH/Y isolates. Multivariable analysis revealed that BI cases were 2.47 times more likely to be associated with fluoroquinolone exposure compared to non-BI cases (95% confidence interval [CI]: 1.12-5.46). In addition, the odds of developing a CDI after third- or fourth-generation cephalosporin exposure was 2.83 times for DH cases than for non-DH cases (95% CI: 1.06-7.54). Fluoroquinolone use in the hospital decreased from 2005 to 2015 from a peak of 113 to a low of 56 antimicrobial days/1,000 patient days. In contrast, cephalosporin use increased from 42 to 81 antimicrobial days/1,000 patient days. These changes correlated with a decrease in geometric mean MIC for ciprofloxacin (61.03 to 42.65 mg/L, P = 0.02) and an increase in geometric mean MIC for ceftriaxone (40.87 to 86.14 mg/L, P < 0.01) among BI isolates. The BI strain remained resistant to fluoroquinolones, but an overall decrease in fluoroquinolone use and increase in cephalosporin use were associated with a decrease in the prevalence of BI, an increased diversity of C. difficile strain types, and the emergence of strains DH and Y.

UNASSIGNED: Gastrointestinal infections affect many people annually. The most common bacterial agents involved in these infections are enteropathogenic bacteria and in the continuation of using broad-spectrum antibiotics, Clostridium difficile-associated diarrhea is involved, especially in hospitalized patients. The aim of the present study was to investigate the pattern of antibiotic resistance among enteropathogenic bacteria.
UNASSIGNED: In this cross-sectional study, 163 samples of patients with diarrhea in Dezful Ganjavian Hospital were examined. The samples were cultured in MacConkey, Hektoen enteric agar and GN broth, and cycloserine cefoxitin fructose agar media and incubated under standard conditions. In order to identify enteropathogenic bacteria, biochemical tests and serological confirmatory tests were used. Antibiotic resistance pattern of the isolates was investigated by Kirby-Bauer disk diffusion susceptibility test.
UNASSIGNED: The frequency of pathogenic bacteria includes 41.1% of Shigella flexneri, followed by 41.1% of S. sonnei, 6.7% of Enteropathogenic E. coli, 5.5% of Salmonella enterica Serogroup B, and 5.5% of Shigella dysenteriae. The results revealed a total of 46 patients with orders regarding C. difficile culture, no C. difficile was isolated from the samples. The studied isolates showed the highest resistance to trimethoprim-sulfamethoxazole, and ceftriaxone (88.3%), and the most effective antibiotic in the treatment of patients was ciprofloxacin with 86% sensitivity.
UNASSIGNED: Susceptibility to antibiotics was different among the isolates, which shows that the early identification of the infection agent and the selection of the correct antibiotic treatment are effective in improving the gastrointestinal infection and preventing the spread of the infection.

Single-domain antibodies (sdAbs), such as VHHs, are increasingly being developed for gastrointestinal (GI) applications against pathogens to strengthen gut health. However, what constitutes a suitable developability profile for applying these proteins in a gastrointestinal setting remains poorly explored. Here, we describe an in vitro methodology for the identification of sdAb derivatives, more specifically divalent VHH constructs, that display extraordinary developability properties for oral delivery and functionality in the GI environment. We showcase this by developing a heterodivalent VHH construct that cross-inhibits the toxic activity of the glycosyltransferase domains (GTDs) from three different toxinotypes of cytotoxin B (TcdB) from lineages of Clostridium difficile. We show that the VHH construct possesses high stability and binding activity under gastric conditions, in the presence of bile salts, and at high temperatures. We suggest that the incorporation of early developability assessment could significantly aid in the efficient discovery of VHHs and related constructs fit for oral delivery and GI applications.

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

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

In a healthy colon, the stratified mucus layer serves as a crucial innate immune barrier to protect the epithelium from microbes. Mucins are complex glycoproteins that serve as a nutrient source for resident microflora and can be exploited by pathogens. We aimed to understand how the intestinal pathogen, Clostridioides difficile, independently uses or manipulates mucus to its benefit, without contributions from members of the microbiota. Using a 2-D primary human intestinal epithelial cell model to generate physiologic mucus, we assessed C. difficile-mucus interactions through growth assays, RNA-Seq, biophysical characterization of mucus, and contextualized metabolic modeling. We found that host-derived mucus promotes C. difficile growth both in vitro and in an infection model. RNA-Seq revealed significant upregulation of genes related to central metabolism in response to mucus, including genes involved in sugar uptake, the Wood-Ljungdahl pathway, and the glycine cleavage system. In addition, we identified differential expression of genes related to sensing and transcriptional control. Analysis of mutants with deletions in highly upregulated genes reflected the complexity of C. difficile-mucus interactions, with potential interplay between sensing and growth. Mucus also stimulated biofilm formation in vitro, which may in turn alter the viscoelastic properties of mucus. Context-specific metabolic modeling confirmed differential metabolism and the predicted importance of enzymes related to serine and glycine catabolism with mucus. Subsequent growth experiments supported these findings, indicating mucus is an important source of serine. Our results better define responses of C. difficile to human gastrointestinal mucus and highlight flexibility in metabolism that may influence pathogenesis.
OBJECTIVE: Clostridioides difficile results in upward of 250,000 infections and 12,000 deaths annually in the United States. Community-acquired infections continue to rise, and recurrent disease is common, emphasizing a vital need to understand C. difficile pathogenesis. C. difficile undoubtedly interacts with colonic mucus, but the extent to which the pathogen can independently respond to and take advantage of this niche has not been explored extensively. Moreover, the metabolic complexity of C. difficile remains poorly understood but likely impacts its capacity to grow and persist in the host. Here, we demonstrate that C. difficile uses native colonic mucus for growth, indicating C. difficile possesses mechanisms to exploit the mucosal niche. Furthermore, mucus induces metabolic shifts and biofilm formation in C. difficile, which has potential ramifications for intestinal colonization. Overall, our work is crucial to better understand the dynamics of C. difficile-mucus interactions in the context of the human gut.

BACKGROUND: Clostridium difficile infection is a serious hospital-acquired infection, causing negative outcomes for those who are afflicted by it. Hospital length of stay is known to be a risk factor for transmission and significant reductions in infection numbers can be realised if transmission is reduced.
METHODS: A Markov model was constructed to compare the impact that five alternative healthcare scenarios had on total C. difficile infections, QALYs gained and total number of patients requiring treatment in ICU. A previously published stochastic transmission model for C. difficile informed scenario effectiveness, while other parameters were estimated from published literature, administrative datasets and expert opinion.
RESULTS: Reducing inpatient LOS disrupts transmission of C. difficile and results in a large reduction of total infections. In turn, an increase in QALYs is expected when the number of infections is reduced. A reduction in infections reduces the number of ICU admissions, which is likely to have a large economic benefit in the Australian setting. Coupling a reduction in overall inpatient LOS with a \'traditional\' infection control intervention, such as hand hygiene or antimicrobial stewardship, improves results further than reducing LOS on its own.
CONCLUSIONS: Implementing a LOS-focused intervention would be a practical challenge, especially for clinicians who already juggle high demand. However, it is not unattainable with the right local endorsement and could have significant benefits for health services.

Paeniclostridium sordellii hemorrhagic toxin (TcsH) and Clostridioides difficile toxin A (TcdA) are two major members of the large clostridial toxin (LCT) family. These two toxins share ~87% similarity and are known to cause severe hemorrhagic pathology in animals. Yet, the pathogenesis of their hemorrhagic toxicity has been mysterious for decades. Here, we examined the liver injury after systemic exposure to different LCTs and found that only TcsH and TcdA induce overt hepatic hemorrhage. By investigating the chimeric and truncated toxins, we demonstrated that the enzymatic domain of TcsH alone is not sufficient to determine its potent hepatic hemorrhagic toxicity in mice. Likewise, the combined repetitive oligopeptide (CROP) domain of TcsH/TcdA alone also failed to explain their strong hemorrhagic activity in mice. Lastly, we showed that disrupting the first two short repeats of CROPs in TcsH and TcdA impaired hemorrhagic toxicity without causing overt changes in cytotoxicity and lethality. These findings lead to a deeper understanding of toxin-induced hemorrhage and the pathogenesis of LCTs and could be insightful in developing therapeutic avenues against clostridial infections.
OBJECTIVE: Paeniclostridium sordellii and Clostridioides difficile infections often cause hemorrhage in the affected tissues and organs, which is mainly attributed to their hemorrhagic toxins, TcsH and TcdA. In this study, we demonstrate that TcsH and TcdA, but not other related toxins. including Clostridioides difficile toxin B and TcsL, induce severe hepatic hemorrhage in mice. We further determine that a small region in TcsH and TcdA is critical for the hemorrhagic toxicity but not cytotoxicity or lethality of these toxins. Based on these results, we propose that the hemorrhagic toxicity of TcsH and TcdA is due to an uncharacterized mechanism, such as the presence of an unknown receptor, and future studies to identify the interactive host factors are warranted.