ABSTRACT
Biofilm formation and toxin production are some of the virulence factors of Clostridioides difficile (C. difficile), which causes hospital-acquired C. difficile infection (HA-CDI). This work investigated the prevalence and distribution of different strains recovered from HA-CDI patients hospitalized in 4 medical centres across Israel, and characterized strains' virulence factors and antibiotic susceptibility. One-hundred and eighty-eight faecal samples were collected. C. difficile 's toxins were detected by the CerTest Clostridium difficile GDH + Toxin A + B combo card test kit. Toxin loci PaLoc and PaCdt were detected by whole-genome sequencing (WGS). Multi-locus sequence typing (MLST) was performed to classify strains. Biofilm production was assessed by crystal violet. Antibiotic susceptibility was determined using Etest. Fidaxomicin susceptibility was tested via agar dilution. Sequence type (ST) 42 was the most (13.8%) common strain. All strains harboured the 2 toxins genes; 6.9% had the binary toxin. Most isolates were susceptible to metronidazole (98.9%) and vancomycin (99.5%). Eleven (5.85%) isolates were fidaxomicin-resistant. Biofilm production capacity was associated with ST (p < 0.001). In conclusion, a broad variety of C. difficile strains circulate in Israel's medical centres. Further studies are needed to explore the differences and their contribution to HA-CDI epidemiology.
Subject(s)
Anti-Bacterial Agents , Biofilms , Clostridioides difficile , Clostridium Infections , Cross Infection , Microbial Sensitivity Tests , Virulence Factors , Clostridioides difficile/genetics , Clostridioides difficile/drug effects , Clostridioides difficile/isolation & purification , Clostridioides difficile/pathogenicity , Humans , Israel/epidemiology , Clostridium Infections/microbiology , Clostridium Infections/epidemiology , Anti-Bacterial Agents/pharmacology , Virulence Factors/genetics , Male , Female , Biofilms/drug effects , Biofilms/growth & development , Cross Infection/microbiology , Cross Infection/epidemiology , Aged , Middle Aged , Multilocus Sequence Typing , Adult , Aged, 80 and over , Whole Genome Sequencing , Feces/microbiologyABSTRACT
We sought to better understand how intestinal microbiota confer protection against Clostridioides difficile (C. difficile) infection (CDI). We utilized gnotobiotic altered Schaedler flora (ASF) mice, which lack the abnormalities of germfree (GF) mice as well as the complexity and heterogeneity of antibiotic-treated mice. Like GF mice, ASF mice were highly prone to rapid lethal CDI, without antibiotics, while very low infectious doses resulted in chronic CDI. Administering such chronic CDI mice an undefined preparation of Clostridia lowered C. difficile levels by several logs. Importantly, such resolution of CDI was associated with colonization of Lachnospiraceae. Fractionation of the Clostridia population to enrich for Lachnospiraceae led to the appreciation that its CDI-impeding property strongly associated with a specific Lachnospiraceae strain, namely uncultured bacteria and archaea (UBA) 3401. UBA3401 was recalcitrant to being propagated as a pure culture but could be maintained in ASF mice, wherein it comprised up to about 50% of the intestinal microbiota, which was sufficient to generate a high-quality genomic sequence of this bacterium. Sequence analysis and ex vivo study of UBA3401 indicated that it had the ability to secrete substance(s) that directly impeded C. difficile growth. Moreover, in vivo administration of UBA3401/ASF feces provided strong protection to C. difficile challenge. Thus, UBA3401 may contribute to and/or provide a means to study microbiota-mediated CDI resistance.
Subject(s)
Clostridiales , Clostridioides difficile , Clostridium Infections , Gastrointestinal Microbiome , Germ-Free Life , Animals , Mice , Clostridioides difficile/genetics , Clostridioides difficile/growth & development , Clostridioides difficile/physiology , Clostridioides difficile/pathogenicity , Clostridium Infections/microbiology , Clostridium Infections/prevention & control , Gastrointestinal Microbiome/drug effects , Clostridiales/genetics , Clostridiales/growth & development , Mice, Inbred C57BL , Disease Models, Animal , Feces/microbiology , Female , Anti-Bacterial Agents/pharmacologyABSTRACT
Clostridioides difficile is an important human pathogen, for which there are very limited treatment options, primarily the glycopeptide antibiotic vancomycin. In recent years, vancomycin resistance has emerged as a serious problem in several gram-positive pathogens, but high-level resistance has yet to be reported for C. difficile, although it is not known if this is due to constraints upon resistance evolution in this species. Here, we show that resistance to vancomycin can evolve rapidly under ramping selection but is accompanied by fitness costs and pleiotropic trade-offs, including sporulation defects that would be expected to severely impact transmission. We identified 2 distinct pathways to resistance, both of which are predicted to result in changes to the muropeptide terminal D-Ala-D-Ala that is the primary target of vancomycin. One of these pathways involves a previously uncharacterised D,D-carboxypeptidase, expression of which is controlled by a dedicated two-component signal transduction system. Our findings suggest that while C. difficile is capable of evolving high-level vancomycin resistance, this outcome may be limited clinically due to pleiotropic effects on key pathogenicity traits. Moreover, our data identify potential mutational routes to resistance that should be considered in genomic surveillance.
Subject(s)
Anti-Bacterial Agents , Clostridioides difficile , Vancomycin Resistance , Vancomycin , Clostridioides difficile/drug effects , Clostridioides difficile/genetics , Clostridioides difficile/pathogenicity , Vancomycin Resistance/genetics , Vancomycin/pharmacology , Anti-Bacterial Agents/pharmacology , Genetic Fitness , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Humans , Signal Transduction , Mutation , Gene Expression Regulation, Bacterial/drug effects , Spores, Bacterial/drug effects , Spores, Bacterial/geneticsABSTRACT
Clostridioides difficile detection in community settings is time-intensive, resulting in delays in diagnosing and quarantining infected individuals. However, with the advent of semi-automated devices and improved algorithms in recent decades, the ability to discern CDI infection from asymptomatic carriage has significantly improved. This, in turn, has led to efficiently regulated monitoring systems, further reducing endemic risk, with recent concerns regarding a possible surge in hospital-acquired Clostridioides difficile infections post-COVID failing to materialize. This review highlights established and emerging technologies used to detect community-acquired Clostridioides difficile in research and clinical settings.
Subject(s)
Clostridioides difficile , Clostridium Infections , Humans , Clostridium Infections/diagnosis , Clostridium Infections/microbiology , Clostridioides difficile/pathogenicity , COVID-19/diagnosisABSTRACT
Clostridioides difficile infection (CDI) poses a significant health threat due to high recurrence rates. Antimicrobial agents are commonly used to manage CDI-related diarrhoea; however, by aggravating intestinal dysbiosis, antibiotics enable C. difficile spores germination and production of toxins, the main virulence factors. Therefore, the binding of exotoxins using adsorbents represents an attractive alternative medication for the prevention and treatment of relapses. In this study, we provided evidence that the natural insoluble polysaccharides, named ABR119, extracted by plant cell cultures, effectively trap C. difficile toxins. In our experiments, ABR119 exhibited no cytotoxicity in vitro and was safely administered in vivo. In the animal model of C. difficile-associated colitis, ABR119 (50â¯mg/kg body weight) significantly reduced the colonic myeloperoxidase activity and severity of inflammation, preventing body weight loss. These effects were not evident when we treated animals with wheat bran polysaccharides. We did not detect bacterial killing effects of ABR119 against C. difficile nor against bacterial species of the normal gut microbiota. Moreover, ABR119 did not interfere in vitro with the antimicrobial activities of most clinically used antibiotics. In summary, ABR119 holds promise for treating and preventing C. difficile colitis by trapping the bacterial toxins, warranting further studies to assess the ABR119 potential in human infections caused by C. difficile.
Subject(s)
Anti-Bacterial Agents , Bacterial Toxins , Clostridioides difficile , Clostridium Infections , Colitis , Disease Models, Animal , Polysaccharides , Polysaccharides/pharmacology , Polysaccharides/metabolism , Clostridioides difficile/drug effects , Clostridioides difficile/pathogenicity , Animals , Colitis/microbiology , Colitis/drug therapy , Colitis/prevention & control , Colitis/chemically induced , Clostridium Infections/prevention & control , Clostridium Infections/microbiology , Clostridium Infections/drug therapy , Bacterial Toxins/metabolism , Anti-Bacterial Agents/pharmacology , Humans , Plant Cells , Mice , Colon/microbiology , Colon/drug effects , Gastrointestinal Microbiome/drug effectsABSTRACT
Clostridioides difficile is the most common causative agent of antibiotic-associated diarrhea. This spore forming, obligate anaerobic, gram-positive bacillus is becoming responsible for an increasing number of infections worldwide, both in community and in hospital settings, whose severity can vary widely from an asymptomatic infection to a lethal disease. While discontinuation of antimicrobial agents and antibiotic treatment of the infection remain the cornerstone of therapy, more recent fecal microbiota transplantation has also been valid as a therapy. The use of probiotics, especially Saccharomyces boulardii CNCM I-745 have become valid forms of prevention therapy. Although there are studies in adults with microbiota-targeted new generation therapies and Clostridium difficile vaccines, there are no data in the paediatric age group yet.
Subject(s)
Anti-Bacterial Agents , Clostridioides difficile , Clostridium Infections , Fecal Microbiota Transplantation , Probiotics , Humans , Clostridium Infections/prevention & control , Clostridium Infections/microbiology , Clostridium Infections/therapy , Clostridioides difficile/pathogenicity , Clostridioides difficile/physiology , Probiotics/therapeutic use , Anti-Bacterial Agents/therapeutic use , Gastrointestinal Microbiome , Diarrhea/prevention & control , Diarrhea/microbiology , Diarrhea/therapyABSTRACT
Clostridioides difficile is the most common cause of nosocomial antibiotic-associated diarrhoea and is responsible for a spectrum of diseases characterized by high levels of recurrence and morbidity. In some cases, complications can lead to death. Currently, several types of animal models have been developed to study various aspects of C. difficile infection (CDI), such as colonization, virulence, transmission and recurrence. These models have also been used to test the role of environmental conditions, such as diet, age and microbiome that modulate infection outcome, and to evaluate several therapeutic strategies. Different rodent models have been used successfully, such as the hamster model and the gnotobiotic and conventional mouse models. These models can be applied to study either the initial CDI infectious process or recurrences. The applications of existing rodent models and their advantages and disadvantages are discussed here.
Subject(s)
Clostridioides difficile , Clostridium Infections , Disease Models, Animal , Animals , Clostridium Infections/microbiology , Clostridioides difficile/pathogenicity , Mice , Cricetinae , Humans , Rodentia/microbiology , Germ-Free LifeABSTRACT
Clostridioides difficile, a Gram-positive anaerobic bacterium, is the leading cause of hospital-acquired antibiotic-associated diarrhea worldwide. The severity of C. difficile infection (CDI) varies, ranging from mild diarrhea to life-threatening conditions such as pseudomembranous colitis and toxic megacolon. Central to the pathogenesis of the infection are toxins produced by C. difficile, with toxin A (TcdA) and toxin B (TcdB) as the main virulence factors. Additionally, some strains produce a third toxin known as C. difficile transferase (CDT). Toxins damage the colonic epithelium, initiating a cascade of cellular events that lead to inflammation, fluid secretion, and further tissue damage within the colon. Mechanistically, the toxins bind to cell surface receptors, internalize, and then inactivate GTPase proteins, disrupting the organization of the cytoskeleton and affecting various Rho-dependent cellular processes. This results in a loss of epithelial barrier functions and the induction of cell death. The third toxin, CDT, however, functions as a binary actin-ADP-ribosylating toxin, causing actin depolymerization and inducing the formation of microtubule-based protrusions. In this review, we summarize our current understanding of the interaction between C. difficile toxins and host cells, elucidating the functional consequences of their actions. Furthermore, we will outline how this knowledge forms the basis for developing innovative, toxin-based strategies for treating and preventing CDI.
Subject(s)
Bacterial Toxins , Clostridioides difficile , Host Microbial Interactions , Clostridioides difficile/genetics , Clostridioides difficile/pathogenicity , Bacterial Toxins/chemistry , Bacterial Toxins/genetics , Bacterial Toxins/immunology , Clostridium Infections/drug therapy , Clostridium Infections/microbiology , Clostridium Infections/pathology , Gene Order , Inflammation/pathology , Humans , AnimalsABSTRACT
Clostridioides difficile infection (CDI) caused by toxigenic C. difficile is the leading cause of antimicrobial and healthcare-associated diarrhea. The pathogenicity of C. difficile relies on the synergistic effect of multiple virulence factors, including spores, flagella, type IV pili (T4P), toxins, and biofilm. Spores enable survival and transmission of C. difficile, while adhesion factors such as flagella and T4P allow C. difficile to colonize and persist in the host intestine. Subsequently, C. difficile produces the toxins TcdA and TcdB, causing pseudomembranous colitis and other C. difficile-associated diseases; adhesion factors bind to the extracellular matrix to form biofilm, allowing C. difficile to evade drug and immune system attack and cause recurrent infection. Cyclic diguanylate (c-di-GMP) is a near-ubiquitous second messenger that extensively regulates morphology, the expression of virulence factors, and multiple physiological processes in C. difficile. In this review, we summarize current knowledge of how c-di-GMP differentially regulates the expression of virulence factors and pathogenesis-related phenotypes in C. difficile. We highlight that C. difficile spore formation and expression of toxin and flagella genes are inhibited at high intracellular levels of c-di-GMP, while T4P biosynthesis, cell aggregation, and biofilm formation are induced. Recent studies have enhanced our understanding of the c-di-GMP signaling networks in C. difficile and provided insights for the development of c-di-GMP-dependent strategies against CDI.
Subject(s)
Bacterial Proteins , Biofilms , Clostridioides difficile , Clostridium Infections , Cyclic GMP , Gene Expression Regulation, Bacterial , Phenotype , Virulence Factors , Clostridioides difficile/pathogenicity , Clostridioides difficile/genetics , Cyclic GMP/analogs & derivatives , Cyclic GMP/metabolism , Virulence Factors/genetics , Virulence Factors/metabolism , Biofilms/growth & development , Humans , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Clostridium Infections/microbiology , Bacterial Toxins/genetics , Bacterial Toxins/metabolism , Spores, Bacterial/genetics , Flagella/genetics , Virulence , Enterotoxins/genetics , Enterotoxins/metabolism , AnimalsABSTRACT
Clostridioides difficile (CD) infections are defined by toxins A (TcdA) and B (TcdB) along with the binary toxin (CDT). The emergence of the 'hypervirulent' (Hv) strain PR 027, along with PR 176 and 181, two decades ago, reshaped CD infection epidemiology in Europe. This study assessed MALDI-TOF mass spectrometry (MALDI-TOF MS) combined with machine learning (ML) and Deep Learning (DL) to identify toxigenic strains (producing TcdA, TcdB with or without CDT) and Hv strains. In total, 201 CD strains were analysed, comprising 151 toxigenic (24 ToxA+B+CDT+, 22 ToxA+B+CDT+ Hv+ and 105 ToxA+B+CDT-) and 50 non-toxigenic (ToxA-B-) strains. The DL-based classifier exhibited a 0.95 negative predictive value for excluding ToxA-B- strains, showcasing accuracy in identifying this strain category. Sensitivity in correctly identifying ToxA+B+CDT- strains ranged from 0.68 to 0.91. Additionally, all classifiers consistently demonstrated high specificity (>0.96) in detecting ToxA+B+CDT+ strains. The classifiers' performances for Hv strain detection were linked to high specificity (≥0.96). This study highlights MALDI-TOF MS enhanced by ML techniques as a rapid and cost-effective tool for identifying CD strain virulence factors. Our results brought a proof-of-concept concerning the ability of MALDI-TOF MS coupled with ML techniques to detect virulence factor and potentially improve the outbreak's management.
Subject(s)
Clostridioides difficile , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Virulence Factors , Clostridioides difficile/genetics , Clostridioides difficile/classification , Clostridioides difficile/chemistry , Clostridioides difficile/pathogenicity , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods , Virulence Factors/genetics , Virulence Factors/analysis , Humans , Clostridium Infections/microbiology , Clostridium Infections/diagnosis , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Bacterial Toxins/genetics , Machine Learning , Deep Learning , Sensitivity and Specificity , Enterotoxins/analysis , Enterotoxins/geneticsABSTRACT
Recurrent Clostridioides difficile infection (CDI) results in significant morbidity and mortality. We previously established that CDI in mice does not protect against reinfection and is associated with poor pathogen-specific B cell memory (Bmem), recapitulating our observations with human Bmem. Here, we demonstrate that the secreted toxin TcdB2 is responsible for subversion of Bmem responses. TcdB2 from an endemic C. difficile strain delayed immunoglobulin G (IgG) class switch following vaccination, attenuated IgG recall to a vaccine booster, and prevented germinal center formation. The mechanism of TcdB2 action included increased B cell CXCR4 expression and responsiveness to its ligand CXCL12, accounting for altered cell migration and a failure of germinal center-dependent Bmem. These results were reproduced in a C. difficile infection model, and a US Food and Drug Administration (FDA)-approved CXCR4-blocking drug rescued germinal center formation. We therefore provide mechanistic insights into C. difficile-associated pathogenesis and illuminate a target for clinical intervention to limit recurrent disease.
Subject(s)
Bacterial Proteins , Bacterial Toxins , Clostridioides difficile , Germinal Center , Receptors, CXCR4 , Animals , Receptors, CXCR4/metabolism , Receptors, CXCR4/immunology , Germinal Center/immunology , Bacterial Proteins/metabolism , Bacterial Proteins/immunology , Bacterial Toxins/immunology , Bacterial Toxins/metabolism , Clostridioides difficile/immunology , Clostridioides difficile/pathogenicity , Mice , Mice, Inbred C57BL , B-Lymphocytes/immunology , B-Lymphocytes/metabolism , Chemokine CXCL12/metabolism , Clostridium Infections/immunology , Clostridium Infections/microbiology , Humans , Immunoglobulin G/immunology , Immunoglobulin G/metabolism , Immunologic Memory , Female , Antibody Formation/immunologyABSTRACT
Clostridioides difficile infection (CDI) with high morbidity and high mortality is an urgent threat to public health, and C. difficile pathogenesis studies are eagerly required for CDI therapy. The major surface layer protein, SlpA, was supposed to play a key role in C. difficile pathogenesis; however, a lack of isogenic slpA mutants has greatly hampered analysis of SlpA functions. In this study, the whole slpA gene was successfully deleted for the first time via CRISPR-Cas9 system. Deletion of slpA in C. difficile resulted in smaller, smother-edged colonies, shorter bacterial cell size, and aggregation in suspension. For life cycle, the mutant demonstrated lower growth (changes of optical density at 600 nm, OD600) but higher cell density (colony-forming unit, CFU), decreased toxins production, and inhibited sporulation. Moreover, the mutant was more impaired in motility, more sensitive to vancomycin and Triton X-100-induced autolysis, releasing more lactate dehydrogenase. In addition, SlpA deficiency led to robust biofilm formation but weak adhesion to human host cells.IMPORTANCEClostridioides difficile infection (CDI) has been the most common hospital-acquired infection, with a high rate of antibiotic resistance and recurrence incidences, become a debilitating public health threat. It is urgently needed to study C. difficile pathogenesis for developing efficient strategies as CDI therapy. SlpA was indicated to play a key role in C. difficile pathogenesis. However, analysis of SlpA functions was hampered due to lack of isogenic slpA mutants. Surprisingly, the first slpA deletion C. difficile strain was generated in this study via CRISPR-Cas9, further negating the previous thought about slpA being essential. Results in this study will provide direct proof for roles of SlpA in C. difficile pathogenesis, which will facilitate future investigations for new targets as vaccines, new therapeutic agents, and intervention strategies in combating CDI.
Subject(s)
Bacterial Proteins , Biofilms , Clostridioides difficile , Clostridium Infections , Gene Deletion , Clostridioides difficile/genetics , Clostridioides difficile/pathogenicity , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Humans , Clostridium Infections/microbiology , Biofilms/growth & development , Anti-Bacterial Agents/pharmacology , Virulence/genetics , CRISPR-Cas Systems , Bacterial Adhesion/genetics , Membrane Glycoproteins/genetics , Membrane Glycoproteins/metabolismABSTRACT
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. IMPORTANCE: 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.
Subject(s)
Bacterial Toxins , Clostridioides difficile , Enterotoxins , Hemorrhage , Animals , Mice , Bacterial Toxins/toxicity , Bacterial Toxins/genetics , Bacterial Toxins/metabolism , Clostridioides difficile/genetics , Clostridioides difficile/pathogenicity , Enterotoxins/toxicity , Enterotoxins/genetics , Enterotoxins/metabolism , Liver/pathology , Clostridium Infections/microbiology , Humans , FemaleABSTRACT
In this editorial we comment on the article published in the recent issue of the World journal of Gastroenterology. We focus specifically on the mechanisms un-derlying the effects of fecal microbiota transplantation (FMT) for irritable bowel syndrome (IBS), the factors which affect the outcomes of FMT in IBS patients, and challenges. FMT has emerged as a efficacious intervention for clostridium difficile infection and holds promise as a therapeutic modality for IBS. The utilization of FMT in the treatment of IBS has undergone scrutiny in numerous randomized controlled trials, yielding divergent outcomes. The current frontier in this field seeks to elucidate these variations, underscore the existing knowledge gaps that necessitate exploration, and provide a guideline for successful FMT imple-mentation in IBS patients. At the same time, the application of FMT as a treatment for IBS confronts several challenges.
Subject(s)
Fecal Microbiota Transplantation , Gastrointestinal Microbiome , Irritable Bowel Syndrome , Irritable Bowel Syndrome/therapy , Irritable Bowel Syndrome/microbiology , Fecal Microbiota Transplantation/methods , Humans , Treatment Outcome , Feces/microbiology , Randomized Controlled Trials as Topic , Clostridioides difficile/pathogenicity , Clostridium Infections/therapy , Clostridium Infections/microbiologyABSTRACT
Spore formation is required for environmental survival and transmission of the human enteropathogenic Clostridioides difficile. In all bacterial spore formers, sporulation is regulated through activation of the master response regulator, Spo0A. However, the factors and mechanisms that directly regulate C. difficile Spo0A activity are not defined. In the well-studied Bacillus species, Spo0A is directly inactivated by Spo0E, a small phosphatase. To understand Spo0E function in C. difficile, we created a null mutation of the spo0E ortholog and assessed sporulation and physiology. The spo0E mutant produced significantly more spores, demonstrating Spo0E represses C. difficile sporulation. Unexpectedly, the spo0E mutant also exhibited increased motility and toxin production, and enhanced virulence in animal infections. We uncovered that Spo0E interacts with both Spo0A and the toxin and motility regulator, RstA. Direct interactions between Spo0A, Spo0E, and RstA constitute a previously unknown molecular switch that coordinates sporulation with motility and toxin production. Reinvestigation of Spo0E function in B. subtilis revealed that Spo0E induced motility, demonstrating Spo0E regulation of motility and sporulation among divergent species. Further, 3D structural analyses of Spo0E revealed specific and exclusive interactions between Spo0E and binding partners in C. difficile and B. subtilis that provide insight into the conservation of this regulatory mechanism among different species.
Subject(s)
Bacterial Proteins , Clostridioides difficile , Gene Expression Regulation, Bacterial , Spores, Bacterial , Clostridioides difficile/pathogenicity , Clostridioides difficile/genetics , Clostridioides difficile/metabolism , Spores, Bacterial/genetics , Virulence , Bacterial Proteins/metabolism , Bacterial Proteins/genetics , Animals , Mice , Clostridium Infections/microbiologyABSTRACT
BACKGROUND: Clostridioides difficile infection (CDI) causes considerable morbidity, mortality, and economic cost. Advanced age, prolonged stay in healthcare facility, and exposure to antibiotics are leading risk factors for CDI. Data on CDI clinical outcomes in the very elderly patients are limited. METHODS: A retrospective cohort study of patients hospitalized between 2016 and 2018 with CDI. We evaluated demographic clinical and laboratory parameters. Major clinical outcomes were evaluated including duration of hospital stay, admission to intensive care unit (ICU), in-hospital mortality, 30 days post-discharge mortality, and readmission/mortality composite outcome. We compared patients aged up to 80 years (elderly) to those of 80 years old or more (very elderly). RESULTS: Of 196 patients included in the study, 112 (57%) were very elderly with a mean age of 86 versus 67 years in the elderly group. The duration of hospital stays, and intensive care unit admission frequency were significantly reduced in the very elderly (13 vs. 22 days p = 0.003 and 1.8% vs. 10.7% p = 0.01, respectively). No significant difference was found in the frequencies of in-hospital and in 30 days post-discharge mortality. CONCLUSIONS: In our cohort, the duration of hospital stay seemed to be shorter in the very elderly with no increase of in-hospital and post-discharge mortality. Although admitted less frequently to ICU, the in-hospital survival of the very elderly was not adversely affected compared to the elderly, suggesting that very advanced age per se should not be a major factor to consider in determining the prognosis of a patient with CDI.
Subject(s)
Clostridium Infections , Length of Stay , Humans , Male , Clostridium Infections/epidemiology , Clostridium Infections/mortality , Aged, 80 and over , Retrospective Studies , Female , Aged , Length of Stay/statistics & numerical data , Clostridioides difficile/pathogenicity , Cohort Studies , Risk Factors , Hospital Mortality , Intensive Care Units/organization & administration , Intensive Care Units/statistics & numerical dataABSTRACT
BACKGROUND: Clostridioides difficile infection (CDI) is the main etiologic agent of antibiotic-associated diarrhea. CDI contributes to gut inflammation and can lead to disruption of the intestinal epithelial barrier. Recently, the rate of CDI cases has been increased. Thus, early diagnosis of C. difficile is critical for controlling the infection and guiding efficacious therapy. APPROACH: A search strategy was set up using the terms C. difficile biomarkers and diagnosis. The found references were classified into two general categories; conventional and advanced methods. RESULTS: The pathogenicity and biomarkers of C. difficile, and the collection manners for CDI-suspected specimens were briefly explained. Then, the conventional CDI diagnostic methods were subtly compared in terms of duration, level of difficulty, sensitivity, advantages, and disadvantages. Thereafter, an extensive review of the various newly proposed techniques available for CDI detection was conducted including nucleic acid isothermal amplification-based methods, biosensors, and gene/single-molecule microarrays. Also, the detection mechanisms, pros and cons of these methods were highlighted and compared with each other. In addition, approximately complete information on FDA-approved platforms for CDI diagnosis was collected. CONCLUSION: To overcome the deficiencies of conventional methods, the potential of advanced methods for C. difficile diagnosis, their direction, perspective, and challenges ahead were discussed.
Subject(s)
Biomarkers , Clostridioides difficile , Clostridium Infections , Clostridioides difficile/genetics , Clostridioides difficile/pathogenicity , Clostridioides difficile/isolation & purification , Humans , Clostridium Infections/diagnosis , Clostridium Infections/microbiologyABSTRACT
OBJECTIVES: In the US, Clostridioides difficile (C. difficile) infection (CDI) is the 8th leading cause of hospital readmission and 7th for mortality among all gastrointestinal (GI) disorders. Here, we investigated GI dysfunction post-CDI in humans and mice post-acute infection. MATERIALS AND METHODS: From March 2020 to July 2021, we reviewed the clinical records of 67 patients referred to the UVA Complicated C. difficile clinic for fecal microbiota transplantation (FMT) eligibility. C57BL/6 mice were infected with C. difficile and clinical scores were determined daily. Stool samples from mice were collected to measure the shedding of C. difficile and myeloperoxidase (MPO) levels. On day 21 post-infection, Evans's blue and FITC-70kDa methods were performed to evaluate GI motility in mice. RESULTS: Of the 67 patients evaluated at the C. difficile clinic, 40 patients (59.7%) were confirmed to have CDI, and 22 patients (32.8%) with post-CDI IBS (diarrhea-type, constipation-type, and mixed-type). In infected mice, levels of MPO in stools and clinical score were higher on day 3. On day 21, mice recovered from body weight loss induced by CDI, and fecal MPO was undetectable. The total GI transit time (TGITT) and FITC-70kDa levels on the proximal colon were increased in infected mice (p = 0.002), suggesting a constipation phenotype post-acute phase of CDI. A positive correlation intestinal inflammation on day 3 and TGITT on day 21 was observed. CONCLUSION: In conclusion, post-infection intestinal dysfunction occurs in humans and mice post-CDI. Importantly, we have validated in the mouse model that CDI causes abnormal GI transit in the recovery phase of the disease, indicating the potential utility of the model in exploring the underlying mechanisms of post-infectious IBS in humans.
Subject(s)
Clostridioides difficile , Clostridium Infections , Mice, Inbred C57BL , Animals , Humans , Clostridium Infections/microbiology , Clostridium Infections/physiopathology , Mice , Clostridioides difficile/pathogenicity , Female , Male , Middle Aged , Disease Models, Animal , Feces/microbiology , Gastrointestinal Diseases/microbiology , Gastrointestinal Diseases/physiopathology , Aged , Fecal Microbiota Transplantation , Adult , Peroxidase/metabolismABSTRACT
Clostridioides difficile infection (CDI) is a major cause of healthcare-associated gastrointestinal infections1,2. The exaggerated colonic inflammation caused by C. difficile toxins such as toxin B (TcdB) damages tissues and promotes C. difficile colonization3-6, but how TcdB causes inflammation is unclear. Here we report that TcdB induces neurogenic inflammation by targeting gut-innervating afferent neurons and pericytes through receptors, including the Frizzled receptors (FZD1, FZD2 and FZD7) in neurons and chondroitin sulfate proteoglycan 4 (CSPG4) in pericytes. TcdB stimulates the secretion of the neuropeptides substance P (SP) and calcitonin gene-related peptide (CGRP) from neurons and pro-inflammatory cytokines from pericytes. Targeted delivery of the TcdB enzymatic domain, through fusion with a detoxified diphtheria toxin, into peptidergic sensory neurons that express exogeneous diphtheria toxin receptor (an approach we term toxogenetics) is sufficient to induce neurogenic inflammation and recapitulates major colonic histopathology associated with CDI. Conversely, mice lacking SP, CGRP or the SP receptor (neurokinin 1 receptor) show reduced pathology in both models of caecal TcdB injection and CDI. Blocking SP or CGRP signalling reduces tissue damage and C. difficile burden in mice infected with a standard C. difficile strain or with hypervirulent strains expressing the TcdB2 variant. Thus, targeting neurogenic inflammation provides a host-oriented therapeutic approach for treating CDI.
Subject(s)
Bacterial Toxins , Clostridioides difficile , Neurogenic Inflammation , Neurons, Afferent , Pericytes , Animals , Mice , Bacterial Toxins/administration & dosage , Bacterial Toxins/pharmacology , Calcitonin Gene-Related Peptide/antagonists & inhibitors , Calcitonin Gene-Related Peptide/metabolism , Clostridioides difficile/pathogenicity , Clostridium Infections/microbiology , Neurogenic Inflammation/chemically induced , Neurogenic Inflammation/microbiology , Neurogenic Inflammation/pathology , Pericytes/drug effects , Pericytes/microbiology , Pericytes/pathology , Receptors, Neurokinin-1/metabolism , Substance P/antagonists & inhibitors , Substance P/metabolism , Neurons, Afferent/drug effects , Neurons, Afferent/microbiology , Neurons, Afferent/pathology , Inflammation Mediators/metabolism , Cecum/drug effects , Cecum/metabolism , Signal Transduction/drug effectsABSTRACT
Clostridioides difficile (C. difficile) is one of the leading causes of infection associated with health care with high morbidity and mortality, especially among hospitalized older adults. The increase in the use of antibiotics has been associated with a higher number of cases and greater virulence. Its clinical presentation ranges from asymptomatic carriers to toxic megacolon. Studies with stool tests (glutamate dehydrogenase, toxins A and B, and nuclear acid amplification techniques) should be considered in these cases. Fidaxomicin, fecal microbiota transplant, and new therapies such as monoclonal antibodies have been incorporated into the therapeutic arsenal, with a higher level of evidence. Nevertheless, the severity, patient comorbidity, recurrence risk factors, and the economic cost of each therapeutic option must be considered. This review aims to update the last guidelines proposed by the Chilean Societies of Gastroenterology and Infectious Diseases published in 2016, providing the latest recommendations regarding prevention, diagnosis, and treatment of C. difficile infection.