scholarly journals Neonatal Piglets Are Protected from Clostridioides difficile Infection by Age-Dependent Increase in Intestinal Microbial Diversity

2021 ◽  
Author(s):  
Alexandra Proctor ◽  
Nancy A. Cornick ◽  
Chong Wang ◽  
Shankumar Mooyottu ◽  
Paulo A. Arruda ◽  
...  
Keyword(s):  
Bacterial Pathogen ◽  
The United States ◽  
Significant Morbidity ◽  
Common Cause ◽  
Content Type ◽  
Neonatal Piglets ◽  
Neonatal Pigs ◽  
Clostridioides Difficile ◽  
Age Dependent ◽  
Clostridioides Difficile Infection

C. difficile is an important bacterial pathogen that is the most common cause of infections associated with health care in the United States. It also causes significant morbidity and mortality in neonatal pigs, and currently there are no preventative treatments available to livestock producers.

scholarly journals Spo0A Suppresses sin Locus Expression in Clostridioides difficile

mSphere ◽  
2020 ◽  
Vol 5 (6) ◽  
Author(s):  
Babita Adhikari Dhungel ◽  
Revathi Govind
Keyword(s):  
Diarrheal Disease ◽  
Toxin Production ◽  
The United States ◽  
Upstream Region ◽  
Pcr Analysis ◽  
Bacterial Cells ◽  
Master Regulator ◽  
Content Type ◽  
Clostridioides Difficile

ABSTRACT Clostridioides difficile is the leading cause of nosocomial infection and is the causative agent of antibiotic-associated diarrhea. The severity of the disease is directly associated with toxin production, and spores are responsible for the transmission and persistence of the organism. Previously, we characterized sin locus regulators SinR and SinR′ (we renamed it SinI), where SinR is the regulator of toxin production and sporulation. The SinI regulator acts as its antagonist. In Bacillus subtilis, Spo0A, the master regulator of sporulation, controls SinR by regulating the expression of its antagonist, sinI. However, the role of Spo0A in the expression of sinR and sinI in C. difficile had not yet been reported. In this study, we tested spo0A mutants in three different C. difficile strains, R20291, UK1, and JIR8094, to understand the role of Spo0A in sin locus expression. Western blot analysis revealed that spo0A mutants had increased SinR levels. Quantitative reverse transcription-PCR (qRT-PCR) analysis of its expression further supported these data. By carrying out genetic and biochemical assays, we show that Spo0A can bind to the upstream region of this locus to regulates its expression. This study provides vital information that Spo0A regulates the sin locus, which controls critical pathogenic traits such as sporulation, toxin production, and motility in C. difficile. IMPORTANCE Clostridioides difficile is the leading cause of antibiotic-associated diarrheal disease in the United States. During infection, C. difficile spores germinate, and the vegetative bacterial cells produce toxins that damage host tissue. In C. difficile, the sin locus is known to regulate both sporulation and toxin production. In this study, we show that Spo0A, the master regulator of sporulation, controls sin locus expression. Results from our study suggest that Spo0A directly regulates the expression of this locus by binding to its upstream DNA region. This observation adds new detail to the gene regulatory network that connects sporulation and toxin production in this pathogen.

scholarly journals Homologous Recombination in Clostridioides difficile Mediates Diversification of Cell Surface Features and Transport Systems

mSphere ◽  
2020 ◽  
Vol 5 (6) ◽  
Author(s):  
Hannah D. Steinberg ◽  
Evan S. Snitkin
Keyword(s):  
Cell Wall ◽  
Homologous Recombination ◽  
Sugar Transport ◽  
The United States ◽  
Strain Typing ◽  
Cell Wall Proteins ◽  
Genetic Loci ◽  
Content Type ◽  
Clostridioides Difficile ◽  
Host Pathogen

ABSTRACT Illness caused by the pathogen Clostridioides difficile is widespread and can range in severity from mild diarrhea to sepsis and death. Strains of C. difficile isolated from human infections exhibit great genetic diversity, leading to the hypothesis that the genetic background of the infecting strain at least partially determines a patient’s clinical course. However, although certain strains of C. difficile have been suggested to be associated with increased severity, strain typing alone has proved insufficient to explain infection severity. The limited explanatory power of strain typing has been hypothesized to be due to genetic variation within strain types, as well as genetic elements shared between strain types. Homologous recombination is an evolutionary mechanism that can result in large genetic differences between two otherwise clonal isolates, and also lead to convergent genotypes in distantly related strains. More than 400 C. difficile genomes were analyzed here to assess the effect of homologous recombination within and between C. difficile clades. Almost three-quarters of single nucleotide variants in the C. difficile phylogeny are predicted to be due to homologous recombination events. Furthermore, recombination events were enriched in genes previously reported to be important to virulence and host-pathogen interactions, such as flagella, cell wall proteins, and sugar transport and metabolism. Thus, by exploring the landscape of homologous recombination in C. difficile, we identified genetic loci whose elevated rates of recombination mediated diversification, making them strong candidates for being mediators of host-pathogen interaction in diverse strains of C. difficile. IMPORTANCE Infections with C. difficile result in up to half a million illnesses and tens of thousands of deaths annually in the United States. The severity of C. difficile illness is dependent on both host and bacterial factors. Studying the evolutionary history of C. difficile pathogens is important for understanding the variation in pathogenicity of these bacteria. This study examines the extent and targets of homologous recombination, a mechanism by which distant strains of bacteria can share genetic material, in hundreds of C. difficile strains and identifies hot spots of realized recombination events. The results of this analysis reveal the importance of homologous recombination in the diversification of genetic loci in C. difficile that are significant in its pathogenicity and host interactions, such as flagellar construction, cell wall proteins, and sugar transport and metabolism.

scholarly journals Fecal microbiota transplantation increases colonic IL-25 and dampens tissue inflammation in patients with recurrent Clostridioides difficile

2021 ◽  
Author(s):  
Ning-Jiun Jan ◽  
Noah Oakland ◽  
Pankaj Kumar ◽  
Girija Ramakrishnan ◽  
Brian W. Behm ◽  
...  
Keyword(s):  
Mononuclear Cells ◽  
Fecal Microbiota Transplantation ◽  
Alpha Diversity ◽  
The United States ◽  
Fecal Microbiota ◽  
Peripheral Blood Mononuclear ◽  
Clostridioides Difficile ◽  
Rdna Sequencing ◽  
Clostridioides Difficile Infection ◽  
The Impact

Background: Clostridioides difficile infection (CDI) is the most common hospital-acquired infection in the United States. Antibiotic-induced dysbiosis is the primary cause of susceptibility and fecal microbiota transplantation (FMT) has emerged as an effective therapy for recurrence. We previously demonstrated in the mouse model of CDI that antibiotic-induced dysbiosis reduced colonic expression of IL-25, and that FMT protected in part by restoring gut commensal bacteria-mediated IL-25 signaling. Here we conducted a prospective clinical trial to test the impact of FMT on immunity, specifically testing in humans if FMT induced IL-25 expression in the colon. Methods: Subjects received colonic biopsies and blood sampling at the time of FMT and 60-days later. Colon biopsies were assayed for IL-25 by immunoassay, for mRNA by RNAseq, and for bacterial content by 16 S rDNA sequencing. High dimensional flow cytometry was also conducted on peripheral blood mononuclear cells pre- and post-FMT. Results: All 10 subjects who received FMT had no CDI recurrences over a 2 year follow-up post FMT. FMT increased alpha diversity of the colonic microbiota and was associated with several immunologic changes. The cytokine IL-25 was increased in colonic tissue. In addition, increased expression of homeostatic genes and repression of inflammatory genes was observed in colonic mRNA transcripts. Finally, circulating Th17 cells were decreased post-FMT. Conclusion: The increase in the cytokine IL-25 accompanied by decreased inflammation is consistent with FMT acting in part to protect from recurrent CDI via restoration of commensal activation of type 2 immunity.

scholarly journals Clostridioides difficile Infection: A Room for Multifaceted Interventions

2020 ◽  
Vol 9 (12) ◽  
pp. 4114
Author(s):  
Nicola Petrosillo ◽  
Maria Adriana Cataldo
Keyword(s):  
United States ◽  
Health Care ◽  
One Health ◽  
The United States ◽  
Clostridioides Difficile ◽  
Clostridioides Difficile Infection ◽  
Multifaceted Interventions ◽  
Infectious Pathogen

Clostridioides difficile (CD) continues to be the number one health care-associated infectious pathogen in the United States [...]

scholarly journals Defining the black box: a narrative review of factors associated with adverse outcomes from severe Clostridioides difficile infection

2021 ◽  
Vol 14 ◽  
pp. 175628482110481
Author(s):  
Adam Ressler ◽  
Joyce Wang ◽  
Krishna Rao
Keyword(s):  
The United States ◽  
Adverse Outcomes ◽  
Chronic Illnesses ◽  
Narrative Review ◽  
Healthcare Associated Infection ◽  
Clostridioides Difficile ◽  
Clostridioides Difficile Infection ◽  
Patients At Risk ◽  
Hospital Deaths ◽  
Healthcare Associated

In the United States, Clostridioides difficile infection (CDI) is the leading cause of healthcare-associated infection, affecting nearly half a million people and resulting in more than 20,000 in-hospital deaths every year. It is therefore imperative to better characterize the intricate interplay between C. difficile microbial factors, host immunologic signatures, and clinical features that are associated with adverse outcomes of severe CDI. In this narrative review, we discuss the implications of C. difficile genetics and virulence factors in the molecular epidemiology of CDI, and the utility of early biomarkers in predicting the clinical trajectory of patients at risk of developing severe CDI. Furthermore, we identify associations between host immune factors and CDI outcomes in both animal models and human studies. Next, we highlight clinical factors including renal dysfunction, aging, blood biomarkers, level of care, and chronic illnesses that can affect severe CDI diagnosis and outcome. Finally, we present our perspectives on two specific treatments pertinent to patient outcomes: metronidazole administration and surgery. Together, this review explores the various venues of CDI research and highlights the importance of integrating microbial, host, and clinical data to help clinicians make optimal treatment decisions based on accurate prediction of disease progression.

scholarly journals Protection from Lethal Clostridioides difficile Infection via Intraspecies Competition for Cogerminant

mBio ◽  
2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Jhansi L. Leslie ◽  
Matthew L. Jenior ◽  
Kimberly C. Vendrov ◽  
Alexandra K. Standke ◽  
Madeline R. Barron ◽  
...  
Keyword(s):  
Virulent Strain ◽  
Single Species ◽  
Multiple Infection ◽  
Life Stages ◽  
Content Type ◽  
Clostridioides Difficile ◽  
Nosocomial Diarrhea ◽  
Clostridioides Difficile Infection ◽  
Intraspecies Competition ◽  
Gut Microbial Community

ABSTRACT Clostridioides difficile, a Gram-positive, spore-forming bacterium, is the primary cause of infectious nosocomial diarrhea. Antibiotics are a major risk factor for C. difficile infection (CDI), as they disrupt the gut microbial community, enabling increased germination of spores and growth of vegetative C. difficile. To date, the only single-species bacterial preparation that has demonstrated efficacy in reducing recurrent CDI in humans is nontoxigenic C. difficile. Using multiple infection models, we determined that precolonization with a less virulent strain is sufficient to protect from challenge with a lethal strain of C. difficile, surprisingly even in the absence of adaptive immunity. Additionally, we showed that protection is dependent on high levels of colonization by the less virulent strain and that it is mediated by exclusion of the invading strain. Our results suggest that reduction of amino acids, specifically glycine following colonization by the first strain of C. difficile, is sufficient to decrease germination of the second strain, thereby limiting colonization by the lethal strain. IMPORTANCE Antibiotic-associated colitis is often caused by infection with the bacterium Clostridioides difficile. In this study, we found that reduction of the amino acid glycine by precolonization with a less virulent strain of C. difficile is sufficient to decrease germination of a second strain. This finding demonstrates that the axis of competition for nutrients can include multiple life stages. This work is important, as it is the first to identify a possible mechanism through which precolonization with C. difficile, a current clinical therapy, provides protection from reinfection. Furthermore, our work suggests that targeting nutrients utilized by all life stages could be an improved strategy for bacterial therapeutics that aim to restore colonization resistance in the gut.

scholarly journals Loss of IL-10 signaling promotes IL-22 dependent host defenses against acute Clostridioides difficile infection

2021 ◽  
Author(s):  
Emily S. Cribas ◽  
Joshua E. Denny ◽  
Jeffrey R. Maslanka ◽  
Michael C. Abt
Keyword(s):  
Defense Mechanisms ◽  
Intestinal Inflammation ◽  
Bacterial Pathogen ◽  
Survival Advantage ◽  
Protective Mechanisms ◽  
Genetic Ablation ◽  
Proinflammatory Mediators ◽  
Clostridioides Difficile ◽  
Clostridioides Difficile Infection ◽  
The Impact

Infection with the bacterial pathogen Clostridioides difficile causes severe damage to the intestinal epithelium that elicits a robust inflammatory response. Markers of intestinal inflammation accurately predict clinical disease severity. However, determining the extent to which host-derived proinflammatory mediators drive pathogenesis versus promote host protective mechanisms remains elusive. In this report, we employed Il10-/- mice as a model of spontaneous colitis to examine the impact of constitutive intestinal immune activation, independent of infection, on C. difficile disease pathogenesis. Upon C. difficile challenge, Il10-/- mice exhibited significantly decreased morbidity and mortality compared to littermate Il10 heterozygote (Il10HET) control mice, despite a comparable C. difficile burden, innate immune response, and microbiota composition following infection. Similarly, antibody-mediated blockade of IL-10 signaling in wild-type C57BL/6 mice conveyed a survival advantage if initiated three weeks prior to infection. In contrast, no advantage was observed if blockade was initiated on the day of infection, suggesting that constitutive activation of inflammatory defense pathways prior to infection mediated host protection. IL-22, a cytokine critical in mounting a protective response against C. difficile infection, was elevated in the intestine of uninfected, antibiotic-treated Il10-/- mice, and genetic ablation of the IL-22 signaling pathway in Il10-/- mice negated the survival advantage following C. difficile challenge. Collectively, these data demonstrate that constitutive loss of IL-10 signaling, via genetic ablation or antibody blockade, enhances IL-22 dependent host defense mechanisms to limit C. difficile pathogenesis.

scholarly journals Immune Profiling To Predict Outcome of Clostridioides difficile Infection

mBio ◽  
2020 ◽  
Vol 11 (3) ◽  
Author(s):  
Mayuresh M. Abhyankar ◽  
Jennie Z. Ma ◽  
Kenneth W. Scully ◽  
Andrew J. Nafziger ◽  
Alyse L. Frisbee ◽  
...  
Keyword(s):  
Prediction Model ◽  
Risk Prediction ◽  
Mortality Risk ◽  
The United States ◽  
Host Bacterium ◽  
Clinical Parameters ◽  
Content Type ◽  
Clostridioides Difficile ◽  
Tnf Α ◽  
Immune Profiling

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.

scholarly journals Type 3 Immunity during Clostridioides difficile Infection: Too Much of a Good Thing?

2019 ◽  
Vol 88 (1) ◽  
Author(s):  
Mahmoud M. Saleh ◽  
William A. Petri
Keyword(s):  
The United States ◽  
Lymphoid Cells ◽  
Interleukin 17 ◽  
Gastrointestinal Infections ◽  
Content Type ◽  
Animal Models Of Disease ◽  
Interleukin 22 ◽  
Inflammatory Conditions ◽  
Clostridioides Difficile ◽  
Type 3

ABSTRACT Clostridioides (formerly known as Clostridium) difficile is the leading cause of hospital-acquired gastrointestinal infections in the United States and one of three urgent health care threats identified by the Centers for Disease Control and Prevention. C. difficile disease is mediated by the production of toxins that disrupt the epithelial barrier and cause a robust host inflammatory response. Studies in humans as well as animal models of disease have shown that the type of immune response generated against the infection dictates the outcome of disease, often irrespective of bacterial burden. Much of the focus on immunity during C. difficile infection (CDI) has been on type 3 immunity because of the established role for this arm of the immune system in other gastrointestinal inflammatory conditions such as inflammatory bowel disease (IBD). For example, interleukin-22 (IL-22) production by group 3 innate lymphoid cells (ILC3s) protects against pathobionts translocating across the epithelium during CDI. On the other hand, interleukin-17 (IL-17) production by Th17 cells increases CDI-associated mortality. Additionally, neutropenia has been associated with increased susceptibility to CDI in humans, but increased neutrophilia in mouse models correlates with host pathology. Taking the data together, these findings suggest dual roles for type 3 immune responses during infection. Here, we review the complex role of type 3 immunity during CDI and delineate what is known about innate and adaptive cellular immunity as well as the downstream effector cytokines known to be important during this infection.

Sign in / Sign up

Export Citation Format

Share Document