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Epiploic foramen entrapment (EFE) is a common cause of small intestinal colic in horses and may lead to intestinal strangulation. Strangulating intestinal obstruction impairs the gastrointestinal outflow and can lead to secondary gastric rupture and endotoxemia. Clostridioides difficile can cause enterotyphlocolitis with colic in horses of all ages, and the process is commonly referred to as C. difficile-associated disease (CDAD). Here we report the results of the postmortem examination of a 7-y-old Thoroughbred racehorse with concurrent CDAD, EFE, and gastric rupture that was euthanized following a history of colic over several days. A segment of distal jejunum and proximal ileum had passed through the epiploic foramen, and the intestinal wall was thickened and dark-red. The remaining small intestinal loops were distended and filled with blood-tinged contents. Peritonitis had resulted from escape of gastric contents into the abdominal cavity through a tear in the major curvature of the stomach. Histologically, the incarcerated segment had acute transmural hemorrhage with congestion and mucosal necrosis; neutrophilic infiltrates with fibrin thrombi were in the mucosa of the non-incarcerated small intestinal segments. C. difficile toxins were detected in the small intestinal contents, and C. difficile was isolated from the small intestine, colon, and cecum.

Objective: Adrenocorticotropic hormone (ACTH) is the first‐line treatment of infantile epileptic spasm syndrome (IESS). Its reported effectiveness varies, and our current understanding regarding the role of gut microbiota composition in IESS treatment response is limited. This study assessed the microbiome–metabolome association to understand the role and mechanism of gut microbiota composition in IESS treatment outcomes. Methods: Children with IESS undergoing ACTH treatment were enrolled. Pre‐treatment stool and serum samples were collected for 16S rRNA gene sequencing and liquid chromatography–tandem mass spectrometry, respectively. The children were divided into "responsive" and "non‐responsive" groups, and gut microbiota and serum metabolome differences were analyzed. Results: Of the 30 patients with IESS, 14 responded to ACTH and 16 did not. The "non‐responsive" group had larger maleficent Clostridioides and Peptoclostridium_phage_p630P populations (linear discriminant analysis >2; false discovery rate q < 0.05). Ten metabolites were upregulated (e.g., xanthurenic acid) and 15 were downregulated (e.g., vanillylmandelic acid) (p < 0.05). Association analysis of the gut microbiome and serum metabolome revealed that Clostridioides and Peptoclostridium_phage_p630P2 were positively correlated with linoleic and xanthurenic acids, while Clostridioides was negatively correlated with vanillylmandelic acid (p < 0.05). A classifier using differential gut bacteria and metabolites achieved an area under the receiver operating characteristic curve of 0.906 to distinguish responders from non‐responders. Conclusion: This study found significant differences in pre‐treatment gut microbiota and serum metabolome between children with IESS who responded to ACTH and those who did not. Additional exploration may provide valuable information for treatment selection and potential interventions. Our results suggest that varying ACTH responses in patients with IESS may be associated with increased gut Clostridioides bacteria and kynurenine pathway alteration, but additional experiments are needed to verify this association. [ABSTRACT FROM AUTHOR]

Bacteria of the genus Clostridium are anaerobic Gram-positive spore-forming bacilli that include more than 200 species. Some of them are known to cause invasive infections and diseases caused by the production of toxins. Some of the diseases that are mediated by toxins are colitis in patients with specific risk factors, such as previous administration of antimicrobials or foodborne botulism. Invasive diseases include bacteremia, infective endocarditis (IE), clostridial myonecrosis (gas gangrene), and other diseases that involve the destruction of soft tissue due to the local production of toxins. The present study aimed to review all cases of IE by Clostridioides and Clostridium species and describe the epidemiology, clinical characteristics, treatment, and outcomes of these infections. A narrative review was performed based on a search in PubMed and Scopus for studies published until 11 September 2023, providing such data of IE caused by Clostridioides and Clostridium species in humans. A total of 20 studies containing data for 21 patients were included. A prosthetic valve was present in 5 patients (23.8%). The aortic valve was the most commonly involved, followed by the mitral valve. Fever, sepsis, and embolic phenomena were the most common clinical presentations. Beta-lactams and metronidazole were the most commonly used antimicrobials. Surgery was performed in nine patients (45%). Mortality reached 33.3%. IE in multiple valves was associated with increased mortality. Despite the heterogeneous genetic and molecular characteristics that necessitate the taxonomic change of some of this genus's previous members, the clinical syndrome of IE caused by these bacteria seems to have similar characteristics. [ABSTRACT FROM AUTHOR]

Combatting Clostridioides difficile infections, a dominant cause of hospital-associated infections with incidence and resulting deaths increasing worldwide, is complicated by the frequent emergence of new virulent strains. Here, we employ whole-genome sequencing, high-throughput phenotypic screenings, and genome-scale models of metabolism to evaluate the genetic diversity of 451 strains of C. difficile. Constructing the C. difficile pangenome based on this set revealed 9,924 distinct gene clusters, of which 2,899 (29%) are defined as core, 2,968 (30%) are defined as unique, and the remaining 4,057 (41%) are defined as accessory. We develop a strain typing method, sequence typing by accessory genome (STAG), that identifies 176 genetically distinct groups of strains and allows for explicit interrogation of accessory gene content. Thirty-five strains representative of the overall set were experimentally profiled on 95 different nutrient sources, revealing 26 distinct growth profiles and unique nutrient preferences; 451 strain-specific genome scale models of metabolism were constructed, allowing us to computationally probe phenotypic diversity in 28,864 unique conditions. The models create a mechanistic link between the observed phenotypes and strain-specific genetic differences and exhibit an ability to correctly predict growth in 76% of measured cases. The typing and model predictions are used to identify and contextualize discriminating genetic features and phenotypes that may contribute to the emergence of new problematic strains.

To determine if there were significant differences produced by 5 of the most prevalent causes of equine enterocolitis, we studied retrospectively the gross and microscopic pathology of 90 cases of enterocolitis submitted to the San Bernardino laboratory of the California Animal Health and Food Safety Laboratory. Included were cases caused by Clostridium perfringens type C (CP; n = 20), Clostridioides difficile (CD; n = 20), Paeniclostridium sordellii (PS; n = 15), Salmonella enterica subspecies enterica serovar Typhimurium (ST; n = 20), and NSAID intoxication (NS; n = 15). Grossly, necrotizing hemorrhagic typhlocolitis was seen most frequently in cases of CD, ST, and NS disease. Cases of CP and PS had enteritis or colitis in similar percentages. Congestion, hemorrhage, and pleocellular inflammatory infiltrates followed by mucosal and submucosal necrosis were the main lesions found in horses with enteritis or colitis produced by any of the etiologic agents investigated. Severe lesions were more frequent in cases of CD and CP than in cases associated with any of the other 3 etiologies. Pseudomembranes were observed with similar prevalence in the small intestine and colon affected by all agents studied. Thrombosis of the lamina propria and/or submucosa was observed in ~50% of the cases of enteritis and colitis by all etiologies, except for PS, in which the majority of the cases had thrombosis. Gross and microscopic lesions of enterocolitis were not sufficiently specific for any of these etiologic agents to enable these enteritides to be distinguished by gross and/or histologic examination.

An intact gut microbiota confers colonization resistance against Clostridioides difficile through a variety of mechanisms, likely including competition for nutrients. Recently, proline was identified as an important environmental amino acid that C. difficile uses to support growth and cause significant disease. A posttranslationally modified form, trans-4-hydroxyproline, is highly abundant in collagen, which is degraded by host proteases in response to C. difficile toxin activity. The ability to dehydrate trans-4-hydroxyproline via the HypD glycyl radical enzyme is widespread among gut microbiota, including C. difficile and members of the commensal Clostridia, suggesting that this amino acid is an important nutrient in the host environment. Therefore, we constructed a C. difficile ΔhypD mutant and found that it was modestly impaired in fitness in a mouse model of infection, and was associated with an altered microbiota when compared to mice challenged with the wild-type strain. Changes in the microbiota between the two groups were largely driven by members of the Lachnospiraceae family and the Clostridium genus. We found that C. difficile and type strains of three commensal Clostridia had significant alterations to their metabolic gene expression in the presence of trans-4-hydroxyproline in vitro. The proline reductase (prd) genes were elevated in C. difficile, consistent with the hypothesis that trans-4-hydroxyproline is used by C. difficile to supply proline for energy metabolism. Similar transcripts were also elevated in some commensal Clostridia tested, although each strain responded differently. This suggests that the uptake and utilization of other nutrients by the commensal Clostridia may be affected by trans-4-hydroxyproline metabolism, highlighting how a common nutrient may be a signal to each organism to adapt to a unique niche. Further elucidation of the differences between them in the presence of hydroxyproline and other key nutrients will be important in determining their role in nutrient competition against C. difficile. IMPORTANCE Proline is an essential environmental amino acid that C. difficile uses to support growth and cause significant disease. A posttranslationally modified form, hydroxyproline, is highly abundant in collagen, which is degraded by host proteases in response to C. difficile toxin activity. The ability to dehydrate hydroxyproline via the HypD glycyl radical enzyme is widespread among gut microbiota, including C. difficile and members of the commensal Clostridia, suggesting that this amino acid is an important nutrient in the host environment. We found that C. difficile and three commensal Clostridia strains had significant, but different, alterations to their metabolic gene expression in the presence of hydroxyproline in vitro. This suggests that the uptake and utilization of other nutrients by the commensal Clostridia may be affected by hydroxyproline metabolism, highlighting how a common nutrient may be a signal to each organism to adapt to a unique niche. Further elucidation of the differences between them in the presence of hydroxyproline and other key nutrients will be important to determining their role in nutrient competition against C. difficile.

Background: Older age is a well‐known risk factor for recurrent and severe Clostridioides difficile infection (CDI). Fecal microbiota transplantation (FMT) is widely recognized as an effective and safe therapeutic option for the treatment of recurrent CDI (rCDI). However, the efficacy and safety of FMT for rCDI in very old patients are uncertain. This study evaluated the efficacy and safety of FMT in a group of very old subjects with rCDI, and the reliability of overall comorbidity and frailty assessment for identifying patients at higher risk of worse clinical outcomes. Methods: This is a retrospective single‐center study including patients ≥85 years undergoing FMT for rCDI between 2014 and 2022. Primary outcomes included efficacy of FMT, defined as cure of CDI at 8 week‐follow‐up, and safety evaluation. At baseline, comorbidity was measured with the Charlson Comorbidity Index (CCI). Frailty was measured with the Clinical Frailty Scale (CFS). Results: Overall, 43 patients with a median age of 88 years underwent FMT by colonoscopy in the study period. The rate of first FMT success was 77%. Five of the 10 patients who failed the first FMT infusion were cured after repeat FMT, with an overall efficacy of 88%. In patients with successful treatment, the CFS was significantly lower compared to those who failed the FMT or underwent repeat FMT (p < 0.01 for both). Mild adverse events occurred in 11 patients (25%). One death, not related to FMT or rCDI, occurred within 7 days from the first procedure. Conclusions: FMT is effective and safe in very old patients. Frailty and high comorbidity do not limit use of FMT in these patients. Frailty assessment has potential to better identify patients at higher risk of worse outcomes or for repeat treatment with FMT. [ABSTRACT FROM AUTHOR]

Clostridioides species possess many virulence factors and alarming levels of muti-drug resistance which make them a significant risk to public health safety and a causative agent of livestock disease. Clostridioides result in serious systemic and gastrointestinal diseases such as myonecrosis, colitis, food poisoning and gastroenteritis. As foodborne pathogens, Clostridioides species are associated with significant incidences of morbidity and mortality where the application of broad-spectrum antibiotics predisposes patients to virulent Clostridioides colonisation. As part of the One Health approach, there is an urgent need to eliminate the use of antibiotics in food production to safeguard animals, humans and the environment. Alternative options are warranted to control foodborne pathogens at all stages of food production. Antimicrobial peptides and bacteriophages have demonstrated efficacy against Clostridioides species and may offer antimicrobial biocontrol options. The bacteriocin nisin, for example, has been implemented as a biopreservative for the control of Listeria, Staphylococcus and Clostridia species in food. Bacteriophage preparations have also gained recognition for the antibacterial action against highly virulent bacterial species including foodborne pathogens. Studies are warranted to mitigate the formulation and administration limitations associated with the application of such antimicrobials as biocontrol strategies. This review outlines foodborne Clostridioides species, their virulence factors, and potential biocontrol options for application in food production. [ABSTRACT FROM AUTHOR]

ObjectiveLack of judicious testing can result in the incorrect diagnosis of Clostridioides difficile infection (CDI), unnecessary CDI treatment, increased costs and falsely augmented hospital-acquired infection (HAI) rates. We evaluated facility-wide interventions used at the VA San Diego Healthcare System (VASDHS) to reduce healthcare-onset, healthcare-facility-associated CDI (HO-HCFA CDI), including the use of diagnostic stewardship with test ordering criteria.DesignWe conducted a retrospective study to assess the effectiveness of measures implemented to reduce the rate of HO-HCFA CDI at the VASDHS from fiscal year (FY)2015 to FY2018.InterventionsMeasures executed in a stepwise fashion included a hand hygiene initiative, prompt isolation of CDI patients, enhanced terminal room cleaning, reduction of fluoroquinolone and proton-pump inhibitor use, laboratory rejection of solid stool samples, and lastly diagnostic stewardship with C. difficile toxin B gene nucleic acid amplification testing (NAAT) criteria instituted in FY2018.ResultsFrom FY2015 to FY2018, 127 cases of HO-HCFA CDI were identified. All rate-reducing initiatives resulted in decreased HO-HCFA cases (from 44 to 13; P ≤ .05). However, the number of HO-HCFA cases (34 to 13; P ≤ .05), potential false-positive testing associated with colonization and laxative use (from 11 to 4), hospital days (from 596 to 332), CDI-related hospitalization costs (from $2,780,681 to $1,534,190) and treatment cost (from $7,158 vs $1,476) decreased substantially following the introduction of diagnostic stewardship with test criteria from FY2017 to FY2018.ConclusionsInitiatives to decrease risk for CDI and diagnostic stewardship of C. difficile stool NAAT significantly reduced HO-HCFA CDI rates, detection of potential false-positives associated with laxative use, and lowered healthcare costs. Diagnostic stewardship itself had the most dramatic impact on outcomes observed and served as an effective tool in reducing HO-HCFA CDI rates.

Current assays for Clostridioides difficile in nonhospital settings are outsourced and time-intensive, resulting in both delayed diagnosis and quarantining of infected individuals. We designed a more rapid point-of-care assay featuring a "turn-on" bioluminescent readout of a C. difficile-specific protease, PPEP-1. NanoLuc, a bright and stable luciferase, was "caged" with a PPEP-1-responsive peptide tail that inhibited luminescence. Upon proteolytic cleavage, the peptide was released and NanoLuc activity was restored, providing a visible readout. The bioluminescent sensor detected PPEP-1 concentrations as low as 10 nM. Sensor uncaging was achieved within minutes, and signal was captured using a digital camera. Importantly, the sensor was also functional at ambient temperature and compatible with fecal material, suggesting that it can be readily deployed in a variety of settings.

Background: The incidence of Clostridioides difficile infection (CDI) is high in ulcerative colitis and is associated with disease flares and adverse outcomes. However, the data on the dynamics of CDI in patients with acute severe ulcerative colitis (ASUC) is rather scarce. We evaluated the prevalence of CDI in patients with ASUC. Methods: This retrospective analysis of a prospectively maintained cohort admitted to the All India Institute of Medical Sciences, India, from May 2016 to December 2021, included patients with ASUC (as per Truelove and Witts criteria) who were tested for CDI. CDI testing was performed using enzyme-linked immunoassay for toxins A and B. Risk factors for developing CDI were analyzed along with short-term outcomes of ASUC. Steroid failure was defined as the need for medical rescue therapy or colectomy. Results: Total 153 patients with ASUC were included (mean age 34.92 ± 12.24 years; males 56.2%; disease duration 36 (IQR: 16–55.5) months, pancolitis 67.3%). Ninety-eight (63.4%), 72 (47%) and 10 (6.5%) patients, respectively, had received steroids, azathioprine and biologics in the past. Forty patients (26.14%) had a prior history of ASUC. Among risk factors for CDI, 14% of the patients had prior admission within 30 days, 22.2% had a recent history of antibiotics and 3.9% had long-term non-steroidal anti-inflammatory drug intake. Only one sample was positive for Clostridioides difficile toxin assay. Tissue Cytomegalovirus DNA-PCR positivity was noted in 57 patients (37.3%). Fifty-seven patients (37.3%) had steroid failure, 35 required medical rescue therapy and 30 (19.6%) required colectomy (eight after medical rescue therapy failure). Conclusion: Despite antecedent risk factors for CDI, the overall prevalence of CDI in ASUC was low and the outcomes were determined by underlying disease severity. [ABSTRACT FROM AUTHOR]

BackgroundPublic reporting of Clostridioides difficile infection (CDI) using laboratory-identified events has led some institutions to revert from molecular-based tests to less sensitive testing modalities. At one academic medical center, researchers chose to use nucleic acid amplification test alone in CDI diagnosis with institutional protocols aimed at diagnostic stewardship.MethodsA single-center, quasi-experimental study was conducted to introduce and analyze the effects of various diagnostic stewardship interventions. In April 2017 an order report was created to inform providers of patients' recent bowel movements, laxative use, and prior Clostridioides difficile (CD) testing (Intervention 1). In November 2017 nursing staff were empowered to not send nondiarrheal stools for testing (Intervention 2). In February 2019, an interruptive alert was implemented to prevent testing that was not indicated (Intervention 3). CD testing rates and healthcare facility-onset CDI (HO-CDI) rates were compared before and after the interventions using one-way analysis of variance (ANOVA).ResultsAt baseline, testing for CD after 3 days of admission was performed at mean ± standard deviation of 15.9 ± 1.7 tests/1,000 patient-days. After Intervention 1, it decreased to 12.1 ± 1.1 tests. This further decreased to 10.6 ± 0.8 after Intervention 2 and to 8.1 ± 0.1 after Intervention 3 (p < 0.001). HO-CDI cases per 10,000 patient-days declined from 12.7 ± 1.4 cases at baseline to 10.7 ± 1.2 after Intervention 1, to 8.7 ± 2.4 after Intervention 2, and to 5.8 ± 0.2 after Intervention 3 (p = 0.03).ConclusionA multidisciplinary approach optimizing electronic health record support tools and leveraging nursing education can reduce both testing and HO-CDI rates while using the most sensitive testing modality.

BackgroundNo studies have evaluated the cost-effectiveness of single and two-step different diagnostic test strategies for Clostridioides difficile infection (CDI), including direct and indirect costs.ObjectiveTo evaluate the cost-effectiveness of commonly available diagnostic tests for CDI including nucleic acid amplification testing (NAAT) alone, glutamate dehydrogenase followed by enzyme immunoassay for toxin (GDH/EIA), GDH then NAAT (GDH/NAAT), and NAAT then EIA (NAAT/EIA).DesignDecision tree model from the US societal perspective with inputs derived from the literature. Willingness-to-pay threshold was set at $150,000 per quality-adjusted life year (QALY) gained. To assess the impact of uncertainty in model inputs on the findings, we performed one-way and probabilistic sensitivity analyses.ParticipantsWe conducted the analysis to represent a population aged 65 years old with diarrhea who received a CDI diagnostic test.Main measuresIncremental cost-effectiveness ratios (ICER) and incremental net monetary benefits (INMB).Key resultsNAAT alone was the most cost-effective approach overall; GDH/NAAT was the most cost-effective two-step option. NAAT alone led to the highest QALYs gained, at an incremental cost of $54,547 (vs. GDH/NAAT), $55,410 (vs. GDH/EIA), and $50,231 (vs. NAAT/EIA) per QALY gained. NAAT/EIA was not cost-effective compared to any other strategy. GDH/NAAT resulted in a higher QALY compared to GDH/EIA, at an incremental cost of $96,841 per QALY gained. Variability in the likelihood of comorbidities, CDI probability, and age at disease onset did not substantially change the results. One-way sensitivity analyses showed that results were most sensitive to likelihood of recurrence, followed by CDI mortality rate and probability of severe CDI. Probabilistic sensitivity analyses explored known uncertainties in the base case and confirmed the robustness of the results.ConclusionsNAAT alone and GDH/NAAT (among the two-step options) were the most cost-effective diagnostic test approaches for CDI.

Background and Aim: Clostridioides difficile infection (CDI) is the leading cause of hospital acquired‐infectious diarrhea in the USA. In this study, we assess the prevalence and impact of CDI in COVID‐19 hospitalizations in the USA. Methods: We used the 2020 National Inpatient Sample database to identify adult patients with COVID‐19. The patients were stratified into two groups based on the presence of CDI. The impact of CDI on outcomes such as in‐hospital mortality, ICU admission, shock, acute kidney injury (AKI), and sepsis rates. Multivariate regression analysis was performed to assess the effects of CDI on outcomes. Results: The study population comprised 1581 585 patients with COVID‐19. Among these, 0.65% of people had a CDI. There was a higher incidence of mortality in patients with COVID‐19 and CDI compared with patients without COVID‐19 (23.25% vs 13.33%, P < 0.001). The patients with COVID‐19 and CDI had a higher incidence of sepsis (7.69% vs 5%, P < 0.001), shock (23.59% vs 8.59%, P < 0.001), ICU admission (25.54% vs 12.28%, P < 0.001), and AKI (47.71% vs 28.52%, P < 0.001). On multivariate analysis, patients with CDI had a statistically significant higher risk of mortality than those without (aOR = 1.47, P < 0.001). We also noted a statistically significant higher risk of sepsis (aOR = 1.47, P < 0.001), shock (aOR = 2.7, P < 0.001), AKI (aOR = 1.55, P < 0.001), and ICU admission (aOR = 2.16, P < 0.001) in the study population. Conclusions: Our study revealed the prevalence of CDI in COVID‐19 patients was 0.65%. Although the prevalence was low, its presence is associated with worse outcomes and higher resource utilization. [ABSTRACT FROM AUTHOR]

Bacteria of the genus Clostridium are anaerobic Gram-positive spore-forming bacilli that include more than 200 species. Some of them are known to cause invasive infections and diseases caused by the production of toxins. Some of the diseases that are mediated by toxins are colitis in patients with specific risk factors, such as previous administration of antimicrobials or foodborne botulism. Invasive diseases include bacteremia, infective endocarditis (IE), clostridial myonecrosis (gas gangrene), and other diseases that involve the destruction of soft tissue due to the local production of toxins. The present study aimed to review all cases of IE by Clostridioides and Clostridium species and describe the epidemiology, clinical characteristics, treatment, and outcomes of these infections. A narrative review was performed based on a search in PubMed and Scopus for studies published until 11 September 2023, providing such data of IE caused by Clostridioides and Clostridium species in humans. A total of 20 studies containing data for 21 patients were included. A prosthetic valve was present in 5 patients (23.8%). The aortic valve was the most commonly involved, followed by the mitral valve. Fever, sepsis, and embolic phenomena were the most common clinical presentations. Beta-lactams and metronidazole were the most commonly used antimicrobials. Surgery was performed in nine patients (45%). Mortality reached 33.3%. IE in multiple valves was associated with increased mortality. Despite the heterogeneous genetic and molecular characteristics that necessitate the taxonomic change of some of this genus’s previous members, the clinical syndrome of IE caused by these bacteria seems to have similar characteristics.

Clostridioides Difficile is considered one of the main causes of the healthcare associated infections worldwide and the main cause of antibiotic-associated diarrhea, with forms of clinical disease ranging from mild to deadly. Both 2021 IDSA and ESCMID guidelines recommend that for the first episode of CDI Fidaxomicin should be considered as the preferred regimen of treatment and Vancomycin becomes 2nd Standard of Care (SOC) line, an alternative to fidaxomicin. Monoclonal antibodies, fecal microbiota transplantation and surgery remain other recommendations in the guidelines. New means of management of Clostridioides Difficile Infection are under development, these including prevention measures (vaccination, population with non-toxigenic strains of the colon, standardized fecal microbiota products) and new antibiotics.

Clostridioides species possess many virulence factors and alarming levels of muti-drug resistance which make them a significant risk to public health safety and a causative agent of livestock disease. Clostridioides result in serious systemic and gastrointestinal diseases such as myonecrosis, colitis, food poisoning and gastroenteritis. As foodborne pathogens, Clostridioides species are associated with significant incidences of morbidity and mortality where the application of broad-spectrum antibiotics predisposes patients to virulent Clostridioides colonisation. As part of the One Health approach, there is an urgent need to eliminate the use of antibiotics in food production to safeguard animals, humans and the environment. Alternative options are warranted to control foodborne pathogens at all stages of food production. Antimicrobial peptides and bacteriophages have demonstrated efficacy against Clostridioides species and may offer antimicrobial biocontrol options. The bacteriocin nisin, for example, has been implemented as a biopreservative for the control of Listeria, Staphylococcus and Clostridia species in food. Bacteriophage preparations have also gained recognition for the antibacterial action against highly virulent bacterial species including foodborne pathogens. Studies are warranted to mitigate the formulation and administration limitations associated with the application of such antimicrobials as biocontrol strategies. This review outlines foodborne Clostridioides species, their virulence factors, and potential biocontrol options for application in food production.

Usually responsible for soft tissue infections, Clostridioides species can also cause bacteremia, life-threatening infections often requiring intensive care unit (ICU) admission. We conducted a multicenter retrospective study to investigate Clostridioides bacteremia in ICUs to describe the clinical and biologic characteristics and outcomes in critically ill patients. We identified 135 patients with Clostridioides bacteremia, which occurred almost exclusively (96%) in patients with underlying conditions. Septic shock and digestive symptoms were the hallmarks of Clostridioides bacteremia in the ICU. We identified 16 different species of Clostridioides, among which C. perfringens accounted for 31% of cases. Despite the high sensitivity of Clostridioides to common antimicrobial drugs, mortality rates were high: 52% for ICU patients and 71% overall at 3 months. In multivariate analysis, the most important factor associated with increased risk for death was the presence of hemolysis. Clostridioides bacteremia often leads to multiple organ failures, which have high mortality rates.

Clostridioides Difficile is considered one of the main causes of the healthcare associated infections worldwide and the main cause of antibiotic-associated diarrhea, with forms of clinical disease ranging from mild to deadly. Both 2021 IDSA and ESCMID guidelines recommend that for the first episode of CDI Fidaxomicin should be considered as the preferred regimen of treatment and Vancomycin becomes 2nd Standard of Care (SOC) line, an alternative to fidaxomicin. Monoclonal antibodies, fecal microbiota transplantation and surgery remain other recommendations in the guidelines. New means of management of Clostridioides Difficile Infection are under development, these including prevention measures (vaccination, population with non-toxigenic strains of the colon, standardized fecal microbiota products) and new antibiotics. [ABSTRACT FROM AUTHOR]

Background:Clostridioides difficile infection (CDI) can result in life-threatening illness requiring surgery. Surgical options for managing severe or fulminant, non-perforated C. difficile colitis include total abdominal colectomy with end ileostomy or creation of a diverting loop ileostomy with antegrade vancomycin lavage. Methods: The Surgical Infection Society's Therapeutics and Guidelines Committee convened to develop guidelines for summarizing the current SIS recommendations for total abdominal colectomy versus diverting loop ileostomy with antegrade lavage for severe or fulminant, non-perforated C. difficile colitis. PubMed, Embase, and the Cochrane database were searched for pertinent studies. Severe infection was defined as laboratory diagnosis of C. difficile infection with leukocytosis (white blood cell count of ≥15,000 cells/mL) or elevated creatinine (serum creatinine level >1.5 mg/dL). Fulminant infection was defined as laboratory diagnosis of C. difficile infection with hypotension or shock, ileus, or megacolon. Perforation was defined as complete disruption of the colon wall. Total abdominal colectomy was defined as resection of the ascending, transverse, descending, and sigmoid colon with end ileostomy. For the purpose of the guideline, the terms subtotal colectomy, total abdominal colectomy, and rectal-sparing total colectomy were used interchangeably. Diverting loop ileostomy with antegrade enema was defined as creation of both a diverting loop ileostomy with intra-operative colonic lavage and post-operative antegrade vancomycin unless otherwise specified. Evaluation of the published evidence was performed using the Grades of Recommendation Assessment, Development and Evaluation (GRADE) system. Using a process of iterative consensus, all committee members voted to accept or reject each recommendation. Results: We recommend that total abdominal colectomy be the procedure of choice for definitive therapy of severe or fulminant, non-perforated C. difficile colitis. In select patients, colon preservation using diverting loop ileostomy with intra-colonic vancomycin may be associated with higher rates of ostomy reversal and restoration of gastrointestinal continuity but may lead to development of recurrent C. difficile colitis. Conclusions: This guideline summarizes the current Surgical Infection Society recommendations regarding use of total abdominal colectomy versus diverting loop ileostomy with antegrade lavage for adults with severe or fulminant, non-perforated C. difficile infection. [ABSTRACT FROM AUTHOR]

The major toxins of Clostridioides difficile (TcdA, TcdB, CDT) are chromosomally encoded in nearly all known strains. Following up on previous findings, we identified 5 examples of a family of putative conjugative plasmids with tcdB and cdtAB in clinical C. difficile isolates from multilocus sequence typing clades C-I, 2, and 4.

Abstract Clostridioides difficile infection (CDI) and recurrent CDI (rCDI) remain associated with a reduction in the patients’ quality of life and with increased healthcare costs. Bezlotoxumab is a monoclonal antibody against toxin B of C. difficile, approved for prevention of rCDI. In this narrative review, we briefly discuss the pathophysiology of CDI and the mechanism of action of bezlotoxumab, as well as the available evidence from investigational and observational studies in terms of efficacy, effectiveness, and safety of bezlotoxumab for the prevention of rCDI. Overall, bezlotoxumab has proved efficacious in reducing the burden of rCDI, thereby providing clinicians with an important novel strategy to achieve sustained cure. Nonetheless, experiences outside randomized controlled trials (RCTs) remain scant, and mostly represented by case series without a control group. Along with the conduction of RCTs to directly compare bezlotoxumab with faecal microbiota transplantation (or to precisely evaluate the role of their combined use), further widening our post-marketing experience remains paramount to firmly guide the use of bezlotoxumab outside RCTs, and to clearly identify those real-life settings where its preventive benefits can be exploited most.

Abstract Background Clostridioides difficile infections have become more frequently diagnosed and associated with greater disease severity, which has resulted in an increase burden on the healthcare system. These increases are attributed to the increased prevalence of hypervirulent strains encompassing select ribotypes. These epidemic ribotypes were characterized as hypervirulent due to higher in vitro spore and toxin production, as well as increased incidence, severity and mortality within patients. However, it is unclear whether epidemic ribotypes are truly more virulent than non-epidemic ribotypes in vivo. Furthermore, there is conflicting evidence about the ability of a strain’s in vitro phenotype to be predictive of their in vivo virulence. The goals of the current studies were to determine if epidemic ribotypes are more virulent than other ribotypes in animal models, and whether the in vitro virulence phenotype of an isolate or ribotype predict in vivo virulence. Results To determine if epidemic strains were truly more virulent than other non-epidemic strains, the in vivo virulence of 13 C. difficile isolates (7 non-epidemic and 6 epidemic ribotype isolates) were determined in murine and hamster models of CDI. The isolates of epidemic ribotype of C. difficile were found to be more virulent in both the murine and hamster models than non-epidemic isolates. In particular, the group of epidemic ribotypes of C. difficile had lower LD50 values in hamsters. The increased severity of disease was associated with higher levels of Toxin A and Toxin B production found in fecal samples, but not numbers of organisms recovered. The isolates were further characterized for their in vitro virulence phenotypes, e.g. toxin production, growth rates, spore formation and adherence of spores to intestinal epithelial cell lines. Although there were higher levels of toxins produced and greater adherence for the group of epidemic ribotypes, the in vitro profiles of individual isolates were not always predictive of their in vivo virulence. Conclusions Overall, the group of epidemic ribotypes of C. difficile were more virulent in vivo despite individual isolates having similar phenotypes to the non-epidemic isolates in vitro.

Objective: To provide a comprehensive characterization of Clostridioides difficile antimicrobial resistance (AMR) data in veterinary medicine based on the minimum inhibitory concentrations (MICs) of all antimicrobial agents tested in relation to the techniques used., Methods: A systematic scoping review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension for scoping reviews (PRISMA-ScR) and its associated checklist. The objective was to provide a synthesis of the evidence in a summarized and analyzed format.To this end, three scientific databases were consulted: Scopus, PubMed, and Web of Science, up until December 2021. Subsequently, all identified literature was subjected to screening and classification in accordance with the established study criteria, with the objective of subsequent evaluation., Study Selection and Data Extraction: A comprehensive analysis was conducted on studies regarding Clostridioides difficile antimicrobial resistance (AMR) in veterinary medicine across various animal species and related sources. The analysis included studies that presented data on antimicrobial susceptibility testing using the E -test, agar dilution, or broth microdilution techniques. The extracted data included minimum inhibitory concentration (MIC) values and a comprehensive characterization analysis., Results: A total of 1582 studies were identified in scientific databases, of which only 80 were subjected to analysis. The research on Clostridioides difficile antimicrobial resistance (AMR) in veterinary medicine is most prolific in Europe and North America. The majority of isolates originate from production animals (55%) and pets (15%), with pigs, horses, and cattle being the most commonly studied species. The tested agents' minimum inhibitory concentrations (MICs) and resulting putative antimicrobial resistance profiles exhibited considerable diversity across animal species and sources of isolation. Additionally, AMR characterization has been conducted at the gene and genomic level in animal strains. The E -test was the most frequently utilized method for antimicrobial susceptibility testing (AST). Furthermore, the breakpoints for interpreting the MICs were found to be highly heterogeneous and frequently observed regardless of the geographical origin of the publication., Conclusions: Antimicrobial susceptibility testing techniques and results were found to be diverse and heterogeneous. There is no evidence of an exclusive antimicrobial resistance pattern in any animal species. Despite the phenotypic and genomic data collected over the years, further interdisciplinary studies are necessary. Our findings underscore the necessity for international collaboration to establish uniform standards for C. difficile antimicrobial susceptibility testing (AST) methods and reporting. Such collaboration would facilitate a "One Health" approach to surveillance and control, which is of paramount importance., Competing Interests: N.A., (© 2024 The Authors.)

Usually responsible for soft tissue infections, Clostridioides species can also cause bacteremia, life-threatening infections often requiring intensive care unit (ICU) admission. We conducted a multicenter retrospective study to investigate Clostridioides bacteremia in ICUs to describe the clinical and biologic characteristics and outcomes in critically ill patients. We identified 135 patients with Clostridioides bacteremia, which occurred almost exclusively (96%) in patients with underlying conditions. Septic shock and digestive symptoms were the hallmarks of Clostridioides bacteremia in the ICU. We identified 16 different species of Clostridioides, among which C. perfringens accounted for 31% of cases. Despite the high sensitivity of Clostridioides to common antimicrobial drugs, mortality rates were high: 52% for ICU patients and 71% overall at 3 months. In multivariate analysis, the most important factor associated with increased risk for death was the presence of hemolysis. Clostridioides bacteremia often leads to multiple organ failures, which have high mortality rates. [ABSTRACT FROM AUTHOR]

Objective: To determine whether residing in a hospital bed that previously held an occupant with Clostridioides difficile increases the risk of hospital-onset C. difficile infection (HO-CDI)., Methods: In this retrospective cohort study, we used a real-time location system to track the movement of hospital beds in 2 academic hospitals from April 2018 to August 2019. We abstracted patient demographics, clinical characteristics, and C. difficile polymerase chain reaction (PCR) results from the medical record. We defined patients as being exposed to a potentially "contaminated" bed or room if, within the preceding 7 days from their HO-CDI diagnosis, they resided in a bed or room respectively, that held an occupant with C. difficile in the previous 90 days. We used multivariable logistic regression to determine whether residing in a contaminated bed was associated with HO-CDI after controlling for time at risk and requiring intensive care. We assessed mediation and interaction from a contaminated hospital room., Results: Of 25,032 hospital encounters with 18,860 unique patients, we identified 237 cases of HO-CDI. Exposure to a contaminated bed was associated with HO-CDI in unadjusted analyses (odds ratio [OR], 1.8; 95% confidence interval [CI], 1.4-2.31) and adjusted analyses (OR, 1.5; 95% CI, 1.2-2.0). Most of this effect was due to both mediation from and interaction with a contaminated hospital room., Conclusions: Residing in a hospital bed or room that previously had a patient with C. difficile increases the risk of HO-CDI. Increased attention to cleaning and disinfecting the healthcare environment may reduce hospital transmission of C. difficile .

Background Clostridioides difficile infection (CDI) represents a significant healthcare challenge associated with antibiotic use and healthcare settings. While healthcare facility-onset CDI (HO-CDI) rates have been extensively studied, the incidence and risk factors of CDI in various settings, including the community, require further investigation. Aim This study aims to examine the incidence rates of CDI in a major governmental hospital in Bahrain, identify risk factors for CDI, and assess the effectiveness of infection control measures. Method We conducted a retrospective study at the Salmaniya Medical Complex (SMC), analyzing all confirmed cases of CDI over a 30-month period from January 2021 to June 2023. CDI cases were screened using glutamine dehydrogenase antigen detection and confirmed using molecular assays like polymerase chain reaction and/or toxin assays for confirmation. The study categorized CDI cases based on their onset (hospital or community) and explored associated risk factors, including antibiotic use, proton pump inhibitor (PPI) therapy, and patient demographics. Infection control practices were also evaluated for their role in managing CDI. Results About 57 new CDI cases were identified during the study period, with a HO-CDI incidence rate of 0.5 per 10,000 patient days. While HO-CDI rates remained stable, community-onset (CO)-CDI cases increased. The median patient age was 61.8 years, without notable differences between genders. Key risk factors for CDI were antimicrobial therapy, use of acid-reducing agents, age, and underlying comorbidities. The mortality rate stood at 35.1%. The ATLAS score (i.e., age, treatment with antibiotics, leukocyte count, albumin level, and serum creatinine) was a reliable predictor of mortality. Critical care admission and low albumin levels emerged as significant independent risk factors for mortality. Conclusions The study demonstrates a low incidence rate of HO-CDI at SMC, attributed to effective infection control and antibiotic stewardship programs. The overall CDI rate increased during the study period, driven by a rise in CO cases; further investigating the risk factors among this category in our study revealed that most patients were exposed to antibiotic therapy within the past three months of their CDI diagnosis. The rise in CO-CDI cases underscores the need for broader community-based interventions and awareness regarding antibiotic and PPI use., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2024, Alkhawaja et al.)

Clostridioides difficile is a leading cause of healthcare-associated infections. The main objective was to assess the current landscape of CDI infection prevention and control (IPC) practices. An anonymous survey of IPC practices for CDI was conducted between July 25 and October 31, 2022. Precautions for symptomatic patients were applicable for 75.9% and were discontinued 48 h minimum after the resolution of diarrhea for 40.7% of respondents. Daily cleaning of CDI patients' rooms was reported by 23 (42.6%). There was unexpected heterogeneity in IPC practices regarding the hospital management of CDI., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Nonmanual room disinfection systems may reduce the transmission of infections. A variety of systems have emerged; however, a paucity of evidence exists to make an evidence-informed decision for the implementation of a specific system. Alberta Health Services assessed one of these systems., Methods: A quasi-experimental prepost design assessed an aerosolized hydrogen peroxide disinfection system on 6 units at 3 acute care facilities in Alberta. To assess clinical effectiveness an interrupted time-series analysis with Poisson distribution compared changes in hospital-acquired Clostridioides difficile infection (HA-CDI) and hospital-acquired Methicillin-resistant Staphylococcus aureus (HA-MRSA) between preintervention, intervention, and postintervention periods. To assess operational feasibility cleaning turnaround time, time to operate, and utilization were considered. A participatory research framework was used to understand the benefits and challenges of operationalization., Results: Incidence rate ratio (IRR) of HA-CDI decreased by 25.7% on FMC-A and 6.9% on RAH-B. Following withdrawal, the IRR of HA-CDI continued to decrease. IRR of HA-MRSA decreased by 25.0% on RAH-B. Following withdrawal, the IRR of HA-MRSA continued to decrease. None of the results were statistically significant. The average time to operate was 3.2 hours. Utilization was between 1.7% and 25.6%. Most staff reported benefits and challenges., Discussion: None of the changes observed in HA-CDI and HA-MRSA after the introduction of the aerosolized hydrogen peroxide system were statistically significant. While most respondents reported multiple benefits and challenges in using the system, the core challenge was delays in inpatient admissions due to the time operate the system., Conclusion: Successful implementation of a nonmanual room disinfection system as an addition to standard cleaning and disinfection requires significant investment and must consider a variety of factors., (Copyright © 2023 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.)

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.IMPORTANCE Clostridioides 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., Competing Interests: The authors declare no conflict of interest.

The gut microbiome engenders colonization resistance against the diarrheal pathogen Clostridioides difficile, but the molecular basis of this colonization resistance is incompletely understood. A prominent class of gut microbiome-produced metabolites important for colonization resistance against C. difficile is short-chain fatty acids (SCFAs). In particular, one SCFA (butyrate) decreases the fitness of C. difficile in vitro and is correlated with C. difficile -inhospitable gut environments, both in mice and in humans. Here, we demonstrate that butyrate-dependent growth inhibition in C. difficile occurs under conditions where C. difficile also produces butyrate as a metabolic end product. Furthermore, we show that exogenous butyrate is internalized into C. difficile cells and is incorporated into intracellular CoA pools where it is metabolized in a reverse (energetically unfavorable) direction to crotonyl-CoA and ( S )-3-hydroxybutyryl-CoA and/or 4-hydroxybutyryl-CoA. This internalization of butyrate and reverse metabolic flow of a butyrogenic pathway(s) in C. difficile coincides with alterations in toxin release and sporulation. Together, this work highlights butyrate as a marker of a C. difficile -inhospitable environment to which C. difficile responds by releasing its diarrheagenic toxins and producing environmentally resistant spores necessary for transmission between hosts. These findings provide foundational data for understanding the molecular and genetic basis of how C. difficile growth is inhibited by butyrate and how butyrate alters C. difficile virulence in the face of a highly competitive and dynamic gut environment.IMPORTANCEThe gut microbiome engenders colonization resistance against the diarrheal pathogen Clostridioides difficile, but the molecular basis of this colonization resistance is incompletely understood, which hinders the development of novel therapeutic interventions for C. difficile infection (CDI). We investigated how C. difficile responds to butyrate, an end-product of gut microbiome community metabolism which inhibits C. difficile growth. We show that exogenously produced butyrate is internalized into C. difficile , which inhibits C. difficile growth by interfering with its own butyrate production. This growth inhibition coincides with increased toxin release from C. difficile cells and the production of environmentally resistant spores necessary for transmission between hosts. Future work to disentangle the molecular mechanisms underlying these growth and virulence phenotypes will likely lead to new strategies to restrict C. difficile growth in the gut and minimize its pathogenesis during CDI., Competing Interests: The authors declare no conflict of interest.

Antimicrobial resistance is emerging in clinical strains of Clostridioides difficile . Ibezapolstat (IBZ) is a DNA polymerase IIIC inhibitor that has completed phase II clinical trials. IBZ has potent in vitro activity against wild-type, susceptible strains but its effect on C. difficile strains with reduced susceptibility to metronidazole (MTZ), vancomycin (VAN), or fidaxomicin (FDX) has not been tested. The primary objective of this study was to test the antibacterial properties of IBZ against multidrug-resistant C. difficile strains. The in vitro activity, bactericidal, and time-kill activity of IBZ versus comparators were evaluated against 100 clinical strains of which 59 had reduced susceptibility to other C. difficile antibiotics. Morphologic changes against a multidrug resistance strain were visualized by light and scanning electron microscopy. The overall IBZ MIC 50/90 values (µg/mL) for evaluated C. difficile strains were 4/8, compared with 2/4 for VAN, 0.5/1 for FDX, and 0.25/4 for MTZ. IBZ MIC 50/90 values did not differ based on non-susceptibility to antibiotic class or number of classes to which strains were non-susceptible. IBZ bactericidal activity was similar to the minimum inhibitory concentration (MIC) and maintained in wild-type and non-susceptible strains. Time-kill assays against two laboratory wild-type and two clinical non-susceptible strains demonstrated sustained IBZ activity despite reduced killing by comparator antibiotics for IBZ and VAN non-susceptible strains. Microscopy visualized increased cell lengthening and cellular damage in multidrug-resistant strains exposed to IBZ sub-MIC concentrations. This study demonstrated the potent antibacterial activity of IBZ against a large collection of C. difficile strains including multidrug-resistant strains. This study highlights the therapeutic potential of IBZ against multidrug-resistant strains of C. difficile ., Competing Interests: K.W.G.: research support paid to his institution from Acurx Pharmaceuticals, Paratek Pharmaceuticals, and Merck Inc., and consulting support from Ferring, Inc. A.J.G.L. received research grants paid to her institution from Seres Therapeutics and is a consultant for Ferring Pharmaceuticals. All other authors declare no conflict of interest.

Clostridioides difficile infections have become a major challenge in medical facilities. The bacterium is capable of spore formation allowing the survival of antibiotic treatment. Therefore, research on the physiology of C. difficile is important for the development of alternative treatment strategies. In this study, we investigated eight putative flavodoxins of C. difficile 630. Flavodoxins are small electron transfer proteins of specifically low potential. The unusually high number of flavodoxins in C. difficile suggests that they are expressed under different conditions. We determined high transcription levels for several flavodoxins during the exponential growth phase, especially for floX . Since flavodoxins are capable of replacing ferredoxins under iron deficiency conditions in other bacteria, we also examined their expression in C. difficile under low iron and no iron levels. In particular, the amount of fldX increased with decreasing iron concentration and thus could possibly replace ferredoxins. Moreover, we demonstrated that fldX is increasingly expressed under different oxidative stress conditions and thus may play an important role in the oxidative stress response. While increased fldX expression was detectable at both RNA and protein level, CD2825 showed increased expression only at mRNA level under H 2 O 2 stress with sufficient iron availability and may indicate hydroxyl radical-dependent transcription. Although the exact function of the individual flavodoxins in C. difficile needs to be further investigated, the present study shows that flavodoxins could play an important role in several physiological processes and under infection-relevant conditions., Importance: The gram-positive, anaerobic, and spore-forming bacterium Clostridioides difficile has become a vast problem in human health care facilities. The antibiotic-associated infection with this intestinal pathogen causes serious and recurrent inflammation of the intestinal epithelium, in many cases with a severe course. To come up with novel targeted therapies against C. difficile infections, a more detailed knowledge on the pathogen's physiology is mandatory. Eight putative flavodoxins, an extraordinarily high copy number of this type of small electron transfer proteins, are annotated for C. difficile . Flavodoxins are known to be essential electron carriers in other bacteria, for instance, during infection-relevant conditions such as iron limitation and oxidative stress. This work is a first and comprehensive overview on characteristics and expression profiles of the putative flavodoxins in the pathogen C. difficile ., Competing Interests: The authors declare no conflict of interest.

ABSTRACT There is a pressing need for biomarker-based models to predict mortality from and recurrence of Clostridioides difficile infection (CDI). Risk stratification would enable targeted interventions such as fecal microbiota transplant, antitoxin antibodies, and colectomy for those at highest risk. Because severity of CDI is associated with the immune response, we immune profiled patients at the time of diagnosis. The levels of 17 cytokines in plasma were measured in 341 CDI inpatients. The primary outcome of interest was 90-day mortality. Increased tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), C-C motif chemokine ligand 5 (CCL-5), suppression of tumorigenicity 2 receptor (sST-2), IL-8, and IL-15 predicted mortality by univariate analysis. After adjusting for demographics and clinical characteristics, the mortality risk (as indicated by the hazard ratio [HR]) was higher for patients in the top 25th percentile for TNF-α (HR = 8.35, P = 0.005) and IL-8 (HR = 4.45, P = 0.01) and lower for CCL-5 (HR = 0.18, P ≤ 0.008). A logistic regression risk prediction model was developed and had an area under the receiver operating characteristic curve (AUC) of 0.91 for 90-day mortality and 0.77 for 90-day recurrence. While limited by being single site and retrospective, our work resulted in a model with a substantially greater predictive ability than white blood cell count. In conclusion, immune profiling demonstrated differences between patients in their response to CDI, offering the promise for precision medicine individualized treatment. IMPORTANCE Clostridioides difficile infection is the most common health care-associated infection in the United States with more than 20% patients experiencing symptomatic recurrence. The complex nature of host-bacterium interactions makes it difficult to predict the course of the disease based solely on clinical parameters. In the present study, we built a robust prediction model using representative plasma biomarkers and clinical parameters for 90-day all-cause mortality. Risk prediction based on immune biomarkers and clinical variables may contribute to treatment selection for patients as well as provide insight into the role of immune system in C. difficile pathogenesis.

• The overall positivity rate of CDAD was 5.2% of 10,995 tested stool samples. • The annual positivity rate was 0.9%-11.8%. • Of all CDAD cases, 230 (39.9%) were community onset-CDAD, 105 (18.2%) community onset-healthcare facility associated (CO-HCFAD), and 242 (42%) healthcare facility onset healthcare facility-associated disease. • There was a trend of increasing percentage of CO-HCFAD from 17% in 2001 to 20% in 2018. • Overall recurrence rate was 16.4%. Clostridioides (Clostridium) difficile infection (CDI) is an important health care-associated infection with variable incidence and prevalence across the globe. There are limited data from Saudi Arabia on the epidemiology of C. difficile -associated diarrhea (CDAD). In this study, we present the epidemiology and incidence of CDAD in a hospital in Saudi Arabia. This study included all stool samples from 2001 to 2018 that were tested for C. difficile. C. difficile toxins were detected by enzyme-linked immunosorbent assay in 2001-2012 and the diagnosis was based on PCR testing (2013-2018). There was a total of 577 distinctive episodes of CDAD representing 5.2% of 10,995 tested stool samples with an annual positivity rate of 0.9%-11.8%. Of all CDAD cases, there were 230 (39.9%) community associated-CDAD, 105 (18.2%) community onset-health care facility associated disease, and 242 (42%) health care facility onset health care facility-associated disease (HCFO-HCFAD). There was a trend of increasing percentage of community onset-health care facility associated disease cases from 17% in 2001 to 20% in 2018 of all cases, and a trend towards less cases of community associated-CDAD from 85% to 50% over time. However, the percentages of HCFO-HCFAD percentages remained relatively stable. The rate of HCFO-HCFAD per 1,000 patient-days increased from 0.009 to 0.22 from 2001 to 2018, respectively. The rate of CDAD was 5.15% among all tested samples and that there is a large proportion of community associated-CDAD. The findings parallel the data from developed countries and deserve further studies in the risk factors for community-associated CDAD. [ABSTRACT FROM AUTHOR]

Clostridioides difficile is the number one cause of hospital-acquired infections in the United States and one of the CDC's urgent-level pathogen threats. The inflammation caused by pathogenic C. difficile results in diarrhea and pseudomembranous colitis. Patients who undergo clinically successful treatment for this disease commonly experience recurrent infections. Current treatment options can eradicate the vegetative cell form of the bacteria but do not impact the spore form, which is impervious to antibiotics and resists conventional environmental cleaning procedures. Antibiotics used in treating C. difficile infections (CDI) often do not eradicate the pathogen and can prevent regeneration of the microbiome, leaving them vulnerable to recurrent CDI and future infections upon subsequent non-CDI-directed antibiotic therapy. Addressing the management of C. difficile spores in the gastrointestinal (GI) tract is important to make further progress in CDI treatment. Currently, no treatment options focus on reducing GI spores throughout CDI antibiotic therapy. This review focuses on colonization of the GI tract, current treatment options and potential treatment directions emphasizing germinant with antibiotic combinations to prevent recurrent disease. [ABSTRACT FROM AUTHOR]

The major toxins of Clostridioides difficile (TcdA, TcdB, CDT) are chromosomally encoded in nearly all known strains. Following up on previous findings, we identified 5 examples of a family of putative conjugative plasmids with tcdB and cdtAB in clinical C. difficile isolates from multilocus sequence typing clades C-I, 2, and 4. [ABSTRACT FROM AUTHOR]

Clostridioides difficile infection (CDI) and recurrent CDI (rCDI) remain associated with a reduction in the patients' quality of life and with increased healthcare costs. Bezlotoxumab is a monoclonal antibody against toxin B of C. difficile, approved for prevention of rCDI. In this narrative review, we briefly discuss the pathophysiology of CDI and the mechanism of action of bezlotoxumab, as well as the available evidence from investigational and observational studies in terms of efficacy, effectiveness, and safety of bezlotoxumab for the prevention of rCDI. Overall, bezlotoxumab has proved efficacious in reducing the burden of rCDI, thereby providing clinicians with an important novel strategy to achieve sustained cure. Nonetheless, experiences outside randomized controlled trials (RCTs) remain scant, and mostly represented by case series without a control group. Along with the conduction of RCTs to directly compare bezlotoxumab with faecal microbiota transplantation (or to precisely evaluate the role of their combined use), further widening our post-marketing experience remains paramount to firmly guide the use of bezlotoxumab outside RCTs, and to clearly identify those real-life settings where its preventive benefits can be exploited most. [ABSTRACT FROM AUTHOR]

Clostridium (Clostridioides) difficile is a gram-positive, spore-forming bacterium that is an important cause of disease in people, a variably important cause of disease in some animal species, and an apparently harmless commensal in others. Regardless of whether it is a known pathogen in a particular species, it can also be found in healthy individuals, sometimes at high prevalences and typically with higher rates of carriage in young individuals. As it is investigated in more animal species, it is apparent that this bacterium is widely disseminated in a diverse range of domestic and wild animal species. Although it can be found in most species in which investigations have been performed, there are pronounced intra- and inter-species differences in prevalence and clinical relevance. A wide range of strains can be identified, some that appear to be animal associated and others that are found in humans and animals. A large percentage of strains that cause disease in people can at least sporadically be found in animals. It is a potentially important zoonotic pathogen, but there is limited direct evidence of animal–human transmission. Although C. difficile has been studied extensively over the past few decades, it remains an enigmatic organism in many ways. [ABSTRACT FROM AUTHOR]

Background: Clostridioides difficile infections have become more frequently diagnosed and associated with greater disease severity, which has resulted in an increase burden on the healthcare system. These increases are attributed to the increased prevalence of hypervirulent strains encompassing select ribotypes. These epidemic ribotypes were characterized as hypervirulent due to higher in vitro spore and toxin production, as well as increased incidence, severity and mortality within patients. However, it is unclear whether epidemic ribotypes are truly more virulent than non-epidemic ribotypes in vivo. Furthermore, there is conflicting evidence about the ability of a strain's in vitro phenotype to be predictive of their in vivo virulence. The goals of the current studies were to determine if epidemic ribotypes are more virulent than other ribotypes in animal models, and whether the in vitro virulence phenotype of an isolate or ribotype predict in vivo virulence. Results: To determine if epidemic strains were truly more virulent than other non-epidemic strains, the in vivo virulence of 13 C. difficile isolates (7 non-epidemic and 6 epidemic ribotype isolates) were determined in murine and hamster models of CDI. The isolates of epidemic ribotype of C. difficile were found to be more virulent in both the murine and hamster models than non-epidemic isolates. In particular, the group of epidemic ribotypes of C. difficile had lower LD50 values in hamsters. The increased severity of disease was associated with higher levels of Toxin A and Toxin B production found in fecal samples, but not numbers of organisms recovered. The isolates were further characterized for their in vitro virulence phenotypes, e.g. toxin production, growth rates, spore formation and adherence of spores to intestinal epithelial cell lines. Although there were higher levels of toxins produced and greater adherence for the group of epidemic ribotypes, the in vitro profiles of individual isolates were not always predictive of their in vivo virulence. Conclusions: Overall, the group of epidemic ribotypes of C. difficile were more virulent in vivo despite individual isolates having similar phenotypes to the non-epidemic isolates in vitro. [ABSTRACT FROM AUTHOR]