The incidence of Clostridium difficile infection in children with and without inflammatory bowel diseases: A single-center study in Taiwan from 2006 to 2019

BACKGROUND

The incidence of Clostridium difficile infection (CDI) is increasing around the world, and patients with inflammatory bowel disease (IBD) have a higher risk of obtaining CDI. The data on the incidence rate of CDI in the Asian pediatric IBD population was lacking.

METHODS

We retrospectively collected data from a tertiary medical center in Taipei, Taiwan. All patients aged 1-18 years old who visited the outpatient department or were admitted to our hospital between 2006 and 2019 were included. CDI was defined as positive stool C. difficile toxin or C. difficile culture results with appropriate antibiotic use within the range of 7 days prior or 14 days after the result.

RESULTS

We compared the average annual incidence of CDI before and after 2013. The average incidence of community-acquired CDI (CA-CDI) increased from 0.063 to 0.564 cases per 1,000 visits, with a rate ratio (RR) of 8.82 (95% CI 5.74-14.38). In patients with IBD, the rate increased from 26.738 to 278.873 cases per 1,000 visits (RR=10.12, 95% CI: 4.57-29.02). The average incidence rate increased from 0.685 to 1.874 cases per 1,000 admissions in pediatric general patients (RR = 2.72, 95% CI 1.82-4.20) and from 14.706 to 62.500 cases per 1,000 admissions in pediatric IBD patients (RR = 3.77, 95% CI 0.71-93.53).

CONCLUSIONS

Both CA-CDI and healthcare facility-onset CDI (HO-CDI) were increasing substantially in the pediatric population over the past decade in Taiwan. Compared to the general pediatric population, pediatric IBD patients had a much higher incidence of CDI.

The small acid-soluble proteins of spore-forming organisms: Similarities and differences in function

The small acid-soluble proteins are found in all endospore-forming organisms and are a major component of spores. Through their DNA binding capabilities, the SASPs shield the DNA from outside insults (e.g., UV and genotoxic chemicals). The absence of the major SASPs results in spores with reduced viability when exposed to UV light and, in at least one case, the inability to complete sporulation. While the SASPs have been characterized for decades, some evidence suggests that using newer technologies to revisit the roles of the SASPs could reveal novel functions in spore regulation.

[A case of disseminated tuberculosis presenting as a metastasizing tumor, complicated by toxic megacolon caused by Clostridium difficile: Difficulties in diagnosis]

A mára ritkán előforduló tuberkulózis (tbc) extrapulmonális manifesztációi előrehaladott rosszindulatú daganatok képét utánozhatják, jelentős diagnosztikus dilemmákat okozva. A tbc igazolása gyakorta bonyolult, komplex vizsgálatokat igényel. Egy fiatal vietnámi nőbeteg esetét ismertetjük, aki idült hasi fájdalom, fogyás, fejfájás, bal oldali hemiparesis miatt jelentkezett kórházunkban. Az urgens vizsgálatok hasi folyadékgyülemek, lymphadenopathia és peritonealis carcinosis képe mellett az uterushoz asszociált ökölnyi kismedencei térfoglaló képletet, intracranialisan agyödémát és metastaticusnak tűnő gócokat ábrázoltak. Neurológiai, belgyógyászati, majd pulmonológiai klinikai vizsgálatok és kezelések során először disszeminált gynaecologiai tumor, majd meningealis-, miliaris tüdő- és kiterjedt hasüregi-kismedencei érintettséggel járó tbc gyanúja fogalmazódott meg. Bár mycobactérium jelenléte nem volt igazolható, antituberculoticus- és komplex antibiotikus terápiát alkalmaztak. Ennek szövődményeként Clostridium difficile okozta enterocolitis alakult ki. Átmeneti állapotrosszabbodás miatti intenzív osztályos kezelést követően a beteget visszahelyezték kórházunk belgyógyászatára. Itt toxicus megacolon, acut peritonitis alakult ki, emiatt sürgős műtétet végeztünk.A hasüregben granulomatosus peritonitis encapsulans, extrém tágult, megrepedt taeniájú colon, hyperaemiás vékonybéltraktus, tuboovarialis tályogok voltak láthatók. Oncotomiát követően salpingo-oophorectomiát és subtotalis colectomiát végeztünk, Brooke szerinti ileostomát készítettünk. Az intenzív osztályos, majd infektológiai kezelésnek köszönhetően a beteg reconvalescentiája sikeres volt, kielégítő állapotban emittálták. A specimenek valós idejű PCR-vizsgálata során Mycobacterium DNS nem volt detektálható, végül a hasüregi váladék és granulomák mikroszkópos vizsgálatával sikerült saválló pálcákat identifikálni.Az eset kapcsán áttekintjük az extrapulmonális tbc diagnosztikus lehetőségeit és terápiás nehézségeit.

Immunogenicity and safety in rabbits of a Clostridioides difficile vaccine combining novel toxoids and a novel adjuvant

Clostridioides difficile infection (CDI) is a serious healthcare-associated disease, causing symptoms such as diarrhea and pseudomembranous colitis. The major virulence factors responsible for the disease symptoms are two secreted cytotoxic proteins, TcdA and TcdB. A parenteral vaccine based on formaldehyde-inactivated TcdA and TcdB supplemented with alum adjuvant, has previously been investigated in humans but resulted in an insufficient immune response. In search for an improved response, we investigated a novel toxin inactivation method and a novel, potent adjuvant. Inactivation of toxins by metal-catalyzed oxidation (MCO) was previously shown to preserve neutralizing epitopes and to annihilate reversion to toxicity. The immunogenicity and safety of TcdA and TcdB inactivated by MCO and combined with a novel carbohydrate fatty acid monosulphate ester-based (CMS) adjuvant were investigated in rabbits. Two or three intramuscular immunizations generated high serum IgG and neutralizing antibody titers against both toxins. The CMS adjuvant increased antibody responses to both toxins while an alum adjuvant control was effective only against TcdA. Systemic safety was evaluated by monitoring body weight, body temperature, and analysis of red and white blood cell counts shortly after immunization. Local safety was assessed by histopathologic examination of the injection site at the end of the study. Body weight gain was constant in all groups. Body temperature increased up to 1 ˚C one day after the first immunization but less after the second or third immunization. White blood cell counts, and percentage of neutrophils increased one day after immunization with CMS-adjuvanted vaccines, but not with alum. Histopathology of the injection sites 42 days after the last injection did not reveal any abnormal tissue reactions. From this study, we conclude that TcdA and TcdB inactivated by MCO and combined with CMS adjuvant demonstrated promising immunogenicity and safety in rabbits and could be a candidate for a vaccine against CDI.

Health care-associated Clostridioides difficile infection: Learning the perspectives of health care workers to build successful strategies

BACKGROUND

Clostridioides difficile (C difficile) is one of the most common health care-associated infections that negatively impact patient care and health care costs. This study takes a unique approach to C difficile infection (CDI) control by investigating key prevention obstacles through the perspectives of Stanford health care (SHC) frontline health care personnel.

METHODS

An anonymous qualitative survey was distributed at SHC, focusing on knowledge and practice of CDI prevention guidelines, as well as education, communication, and perspectives regarding CDI at SHC.

RESULTS

112 survey responses were analyzed. Our findings unveiled gaps in personnel's knowledge of C difficile diagnostic guidelines and revealed a need for targeted communication and guideline-focused education. Health care staff shared preferences and recommendations, with the majority recommending enhanced communication of guidelines and information as a strategy for reducing CDI rates. The findings were then used to design and propose internal recommendations for SHC to mitigate the gaps found.

DISCUSSION

Many guidelines and improvement strategies are based on strong scientific and medical foundations; however, it is important to ask whether these guidelines are effectively translated into practice. Frontline health care workers hold empirical perspectives that could be key in infection control.

CONCLUSIONS

Our findings emphasize the importance of including frontline health care personnel in infection prevention decision-making processes and the strategies presented here can be applied to mitigating infections in different health care settings.

Assessment of Knowledge and Practice of Healthcare Providers in Saudi Arabia Regarding Clostridioides difficile Infection Diagnosis and Management: A Cross-Sectional Questionnaire-Based Study

Introduction

Diagnosis of Clostridioides difficile infection (CDI) depends on clinical presentation and laboratory testing. Stool diagnostic tests are essential for effective detection of toxigenic C. difficile strains. No study to date has evaluated the readability of microbiology labs in Saudi Arabia to test for CDI and evaluated the knowledge and practice of healthcare providers regarding CDI management. Therefore, this study aimed to assess the knowledge and practice of healthcare providers in Saudi Arabia regarding CDI diagnosis and treatment.

Methods

A cross-sectional, descriptive, questionnaire-based study was conducted on healthcare providers in Saudi Arabia, primarily physicians and clinical pharmacists. The questionnaire was developed based on a literature review and input from infectious diseases experts. The questionnaire was administered online. Data were analyzed using descriptive and inferential statistics.

Results

Of 183 respondents, 27.9% had adequate knowledge on CDI diagnosis and management. The majority were internal medicine specialists (37.7%) working in governmental or semi-governmental hospitals (80.9%) in central (46.6%) or southern (30.1%) regions of Saudi Arabia. Most participants assessed laxative use (86.3%) and reported positive C. difficile specimens to infection control (67.2%). However, knowledge varied, with 57.4% supporting unnecessary retesting and 53% assuming positive PCR test indicates moderate CDI probability. Factors such as specialization, hospital accreditation status, and bed capacity influenced knowledge levels (p<0.01 for all factors).

Conclusion

The study revealed a significant knowledge gap among Saudi healthcare providers regarding CDI diagnosis, management, and severity classification, highlighting the need for improved education and adherence to guidelines to improve patient outcomes and reduce recurrence risks.

Fecal Microbiota Transplantation for Clostridium difficile-associated Diarrhea in Hematopoietic Stem Cell Transplant Recipients: A Single-center Experience from a Tertiary Center in India

Objectives

Fecal microbiota transplantation (FMT) is an emerging option for recurrent or refractory Clostridium difficile-associated diarrhea (CDAD). We describe a single-center experience of FMT in hematopoietic stem cell transplant (HSCT) recipients with CDAD in India.

Methods

A prospective observational study of HSCT recipients with CDAD who received FMT in our center.

Results

A total of 13 patients were included. All the patients were allogenic HSCT recipients; FMT was performed in seven patients due to refractory CDAD, in five patients due to the presence of both CDAD and graft vs host disease (GVHD), and in 1 patient due to recurrent CDAD. The approach to FMT was colonoscopic in 10 (77%) patients. Only one patient reported bacteremia and one patient had candidemia, both of which were unrelated to FMT. Of the 10 patients who had complete resolution of CDAD, only one patient presented with a recurrence of CDAD within 8 weeks post-FMT.

Conclusion

This is the first study from India using FMT as a therapeutic modality for CDAD in the setting of HSCT. Here we demonstrate that FMT in India is an effective option, especially when patients have refractory CDAD, recurrent CDAD, or both GVHD and CDAD. Further studies should explore the efficacy and feasibility of FMT in India.

How to cite this article

Prayag PS, Patwardhan SA, Ajapuje PS, Melinkeri S, Gadhikar H, Palnitkar S, et al. Fecal Microbiota Transplantation for Clostridium difficile-associated Diarrhea in Hematopoietic Stem Cell Transplant Recipients: A Single-center Experience from a Tertiary Center in India. Indian J Crit Care Med 2024;28(2):106-110.

Diagnostic considerations in the clinical management of sudden swelling of the knee: a case report and review of the literature

BACKGROUND

Reactive arthritis and septic arthritis rarely present concomitantly in the same joint and patient. Reactive arthritis presenting after coronavirus disease 2019 is also exceedingly rare, with less than 30 cases reported thus far. Less common pathogens such as Clostridium difficile have been reported to cause reactive arthritis, especially in patients with a positive human leukocyte antigen B27, and therefore should be considered in diagnostic algorithms. The aim of this case report is to highlight the difficulties and precautions in discerning and diagnosing patients presenting with sudden swelling of the knee.

CASE PRESENTATION

We report the case of a 70-year-old Caucasian male with a recent history of coronavirus disease 2019 upper respiratory infection and diarrhea and negating trauma, who presented with a swollen and painful knee. Pain and swelling worsened and inflammatory parameters increased after an intraarticular corticosteroid injection. The patient was therefore treated with arthroscopic lavage and intravenous antibiotics for suspected septic arthritis. Synovial fluid and synovium samples were taken and sent for microbiological analysis. Synovial fluid cytology showed increased leukocytes at 10,980 × 106/L, while polymerase chain reaction and cultures came back sterile. Clostridium difficile toxin was later detected from a stool sample and the patient was treated with oral vancomycin. The patient was tested for the presence of human leukocyte antigen B27, which was positive. We present a review of the literature about the challenges of distinguishing septic from reactive arthritis, and about the mechanisms that predispose certain patients to this rheumatological disease.

CONCLUSIONS

It is still a challenge to differentiate between septic and reactive arthritis of the knee, and it is even more challenging to identify the exact cause of reactive arthritis. This case report of a human leukocyte antigen-B27-positive patient highlights the necessity of contemplating different, less common causes of a swollen knee joint as a differential diagnosis of an apparent septic infection, especially in the coronavirus disease 2019 era. Treating the patient for septic arthritis prevented any possible complications of such a condition, while treating the C. difficile infection contributed to the substantial relief of symptoms.

Comparison of Clostridioides difficile nucleic acid amplification test (NAAT) results using fresh and frozen stool specimens and rectal swabs

IMPORTANCE

Nucleic acid amplification tests (NAATs) are frequently used in Clostridioides difficile research and diagnostic testing, but the effect of freezing specimens on C. difficile NAAT performance is not well characterized. This study evaluated the concordance of NAAT results between fresh and frozen specimens (fecal and rectal swabs) and found it to be very good to excellent. The results indicate that frozen fecal and rectal swab specimens may be used for C. difficile NAAT testing in research when fresh specimens are not available.

Fecal calprotectin level is nonlinearly associated with GI pathogen detection in patients with and without inflammatory bowel disease

Fecal calprotectin (FCP) is used to monitor inflammatory bowel disease (IBD) activity and can also be elevated in gastrointestinal infections. Our study's objective was to quantify the relationship between FCP levels and lab-confirmed infections in people with and without IBD. We performed a cross-sectional study at a tertiary-care center of all encounters during which FCP and gastrointestinal pathogen polymerase-chain reaction (GI PCR) panel testings were conducted. Using non-parametric tests and quantile regression, we compared the FCP levels by IBD status and pathogen detection. There were 3,347 encounters with FCP and GI PCR testings from 2,780 unique individuals between 1 August 2016 and 17 February 2022. Overall, 54.4% had IBD (n = 1,819). Pathogens were detected in 744 encounters (22.2%), and the detection rate did not differ by IBD status. Median FCP without IBD was significantly elevated when a pathogen was detected (64 vs 41 mg/kg, P = 0.0003, normal ≤50.0 mg/kg), but FCP with IBD was not significantly elevated when a pathogen was detected (299 vs 255 mg/kg, P = 0.207). In quantile regression adjusted for age and IBD, pathogen detection was only significantly associated with higher FCP in the lower two quartiles, though IBD remained significantly associated with higher FCP at all levels (P > 0.001). Pathogen detection by GI PCR is associated with elevated FCP, though this relationship is nonlinear and varies by IBD status. Our findings indicate that FCP may be an adjunct to, but not a substitute for, stool pathogen testing.

Development of a Protocol for Anaerobic Preparation and Banking of Fecal Microbiota Transplantation Material: Evaluation of Bacterial Richness in the Cultivated Fraction

Fecal microbiota transplantation (FMT) has shown highly variable results in indications beyond recurrent Clostridioides difficile infection. Microbiota dysbiosis in many diseases is characterized by the depletion of strictly anaerobic bacteria, which may be crucial for FMT efficacy. We developed a protocol to ensure anaerobic conditions during the entire transplant preparation and banking process, from material collection to administration. The protocol necessitates an anaerobic cabinet, i.e., a non-standard laboratory equipment. We analyzed the population of viable anaerobes by combining cultivation and 16S rRNA gene profiling during the transplant preparation, and after 4, 8, and 12 months of anaerobic or aerobic storage at -80 °C, 78% of fecal species were captured via cultivation. Our findings suggest that strictly anaerobic transplant preparation and storage may preserve species richness better than oxic conditions, but the overall difference was not significant. However, specific anaerobes such as Neglecta and Anaerotruncus were affected by the oxygen exposure. A storage time of up to 12 months did not affect the presence of cultivated taxa. Noteworthy, our analysis focused on the richness of cultivated anaerobes rather than their abundance, which may have been affected. The benefits of the developed anaerobic protocol in FMT for specific indications remain to be demonstrated in clinical trials.

Inflammatory bowel disease and Clostridium difficile infection: clinical presentation, diagnosis, and management

As a frequent complication of inflammatory bowel disease (IBD), Clostridium difficile infection (CDI) was confirmed to not only aggravate the symptoms of IBD but also result in unexpected outcomes, including death. With the increasing prevalence rate of IBD and the updating of CDI diagnosis, the incidence of CDI in IBD patients is also seen rising. Although a detection method consisting of glutamate dehydrogenase immunoassay or nucleic acid amplification test and then toxin A/B enzyme immunoassay was recommended and widely adopted, the diagnosis of CDI in IBD is still a challenge because of the overlap between the symptoms of CDI in IBD and CDI itself. Vancomycin and fidaxomicin are the first-line therapy for CDI in IBD; however, the treatment has different effects due to the complexity of IBD patients' conditions and the choice of different treatment schemes. Although the use of fecal microbial transplantation is now in the ascendant for IBD management, the prospects are still uncertain and the prevention and treatment of the recurrence of CDI in IBD remain a clinical challenge. In this paper, the epidemiology, pathophysiology, clinical manifestation, prevention, and therapy of CDI in IBD were summarized and presented.

Diarrheal woes in transplantation from real world settings with special focus on clostridium difficile infection

Background

Diarrhea is the major cause of discomfort and morbidity of patients undergoing hematopoietic stem cell transplant (HSCT). The cause of diarrhea may be infective or non-infective.

Methods

This is a prospective single center observational study from North India conducted over a period of approximately 4 years among 105 patients who underwent HSCT (autologous-72, allogeneic-33). The objective of the study was to identify the overall incidence and characteristics of diarrhea in HSCT in the real world, to evaluate any differences among allogeneic or autologous transplants, incidence of C Difficile among diarrheal patients, and antimicrobial usage among these patients.

Results

Diarrhea was present in 89 of 105 patients (84.7%). The mean diarrheal duration was of 8.39±4.57 days (range: 1-24 days). There was non statistical difference between the incidence of diarrhea amongst allogeneic and autologous transplants (78.9% Vs 87.5%). Out of 89 patients with diarrhea, 13 were CDTA positive. We could isolate Clostridium difficile in culture in only 7.6% of patients with CDTA positivity. Metronidazole was the antibiotic of choice for diarrhea in our post-transplant settings. Metronidazole was prescribed for a median duration of 8 days (Range: 3-18 days). Seventeen patients received oral vancomycin with a median duration of 8 days (Range: 5-14 days).

Conclusion

We conclude by saying that diarrhea was a common post-transplant morbidity. Clostridium difficile is not common in patients with the diarrhea post hematopoietic stem cell transplant. All cases of diarrhea need not be infective particularly in allogeneic settings.

Absence of toll-like receptor 7 ameliorates survival and reduces intestinal injury in mice after Clostridium difficile infection

Clostridioides difficile (CD) is a major cause of antibiotic-associated diarrhea and pseudomembranous enteritis. C. difficile infection (CDI) is increasingly present in the community and represents a significant burden on the healthcare system. Identification of novel immune-based therapeutic targets from a better understanding of their molecular pathogenesis is urgently required. Toll-like receptor 7 (TLR7) is an important pattern recognition receptor and function as an immune sensor that can trigger host defenses against pathogens, but the relationship between TLR7 and CDI remains unknown. Here, we reported that the expression levels of TLR7 increased significantly in patients and mice with CDI. Absence of TLR7 in mice with CDI demonstrated enhanced bacterial clearance of intestinal contents and reduced intestinal inflammation, edema, injury and prolonged the survival. TLR7 loss decreased the concentrations of tumor necrosis factor (TNF)-α, interferon (IFN)-γ and IFN-α1 in the intestine and improved tissue damage and inflammation. Flow cytometry and immunofluorescence results indicated that TLR7 enhanced leukocyte recruitment in the infected intestine. In-vitro results have shown that TLR7 impairs the phagocytosis and killing ability of macrophages to CD, prompts reactive oxygen species (ROS) production and accelerates apoptosis. To our knowledge, our study first identified TLR7 as a critical factor that contributes to the immunopathology of CDI, suggesting that targeting TLR7 might serve as a potential treatment for CDI.

Discrimination between hypervirulent and non-hypervirulent ribotypes of Clostridioides difficile by MALDI-TOF mass spectrometry and machine learning

Hypervirulent ribotypes (HVRTs) of Clostridioides difficile such as ribotype (RT) 027 are epidemiologically important. This study evaluated whether MALDI-TOF can distinguish between strains of HVRTs and non-HVRTs commonly found in Europe. Obtained spectra of clinical C. difficile isolates (training set, 157 isolates) covering epidemiologically relevant HVRTs and non-HVRTs found in Europe were used as an input for different machine learning (ML) models. Another 83 isolates were used as a validation set. Direct comparison of MALDI-TOF spectra obtained from HVRTs and non-HVRTs did not allow to discriminate between these two groups, while using these spectra with certain ML models could differentiate HVRTs from non-HVRTs with an accuracy >95% and allowed for a sub-clustering of three HVRT subgroups (RT027/RT176, RT023, RT045/078/126/127). MALDI-TOF combined with ML represents a reliable tool for rapid identification of major European HVRTs.

Detection of Clostridium difficile among diarrheic children using cultural and polymerase chain reaction technique

INTRODUCTION

Clostridium difficile is the most common cause of antibiotic-associated diarrhea and colitis. Several methods are available for the detection of C. difficile in stool samples. This study aimed to use glutamate dehydrogenase (GDH), toxin detection, culture and polymerase chain reaction (PCR) techniques for the diagnosis of this pathogen.

METHODOLOGY

A total of 300 stool samples were collected from children with hospital acquired diarrhea (HA-D), community acquired diarrhea (CA-D), and hospitalized non-diarrheic children as control with ages ranging from 6 months to 6 years (mean 3.7 ± 1.7). Each stool sample was divided into two parts; one part was tested for the enzyme GDH, toxin A and B and then cultured on selective media; and the other part for direct DNA extraction.

RESULTS

From a total of 300 stool samples, 9 (3.0%) were positive for C. difficile by the PCR technique, 7 (7%) samples of which were from HA-D cases and 2 (2.0%) from CA-D cases; the control group samples were negative. The enzyme GDH was detected in 12 (12%) samples and toxins A and B in 8 (8%) samples from HA-D cases compared to 5 (5%) and 2 (2%), respectively from CA-D cases. Both GDH and the toxins were negative in control samples. Only 19 (19.0%) samples from HA-D cases gave suspected growth and all of these were negative by PCR.

CONCLUSIONS

Based on the results of this study, we conclude that the PCR technique is the only reliable method for the diagnosis of this pathogen.

Nectin-3 and shed forms of CSPG4 can serve as epithelial cell receptors for Clostridioides difficile TcdB

IMPORTANCE

Toxin B (TcdB) is a major virulence factor of Clostridioides difficile, a Gram-positive pathogen that is a leading cause of hospital-acquired diarrhea. While previous studies have established that TcdB can engage multiple cell surface receptors in vitro, little is known about how these interactions promote disease and where these receptors localize on colonic tissue. Here, we used immunofluorescence microscopy to visualize Nectin-3 and CSPG4 on tissue, revealing unexpected localization of both receptors on colonic epithelial cells. We show that Nectin-3, which was previously characterized as an adherens junction protein, is also localized to the brush border of colonocytes. Staining for CSPG4 revealed that it is present along epithelial cell junctions, suggesting that it is shed by fibroblasts along the crypt-surface axis. Collectively, our study provides new insights into how TcdB can gain access to the receptors Nectin-3 and CSPG4 to intoxicate colonic epithelial cells.

A high-throughput structural system biology approach to increase structure representation of proteins from Clostridioides difficile

Clostridioides difficile causes life-threatening gastrointestinal infections. It is a high-risk pathogen due to a lack of effective treatments, antimicrobial resistance, and a poorly conserved genomic core. Herein, we report 30 X-ray structures from a structure genomics pipeline spanning 13 years, representing 10.2% of the X-ray structures for this important pathogen.

Glycine fermentation by C. difficile promotes virulence and spore formation, and is induced by host cathelicidin

Clostridioides difficile is a leading cause of antibiotic-associated diarrheal disease. C. difficile colonization, growth, and toxin production in the intestine is strongly associated with its ability to use amino acids to generate energy, but little is known about the impact of specific amino acids on C. difficile pathogenesis. The amino acid glycine is enriched in the dysbiotic gut and is suspected to contribute to C. difficile infection. We hypothesized that the use of glycine as an energy source contributes to colonization of the intestine and pathogenesis of C. difficile. To test this hypothesis, we deleted the glycine reductase (GR) genes grdAB, rendering C. difficile unable to ferment glycine, and investigated the impact on growth and pathogenesis. Our data show that the grd pathway promotes growth, toxin production, and sporulation. Glycine fermentation also had a significant impact on toxin production and pathogenesis of C. difficile in the hamster model of disease. Furthermore, we determined that the grd locus is regulated by host cathelicidin (LL-37) and the cathelicidin-responsive regulator, ClnR, indicating that the host peptide signals to control glycine catabolism. The induction of glycine fermentation by LL-37 demonstrates a direct link between the host immune response and the bacterial reactions of toxin production and spore formation.

Short-Chain Fatty Acid Levels after Fecal Microbiota Transplantation in a Pediatric Cohort with Recurrent Clostridioides difficile Infection

Though antibiotics are the mainstay treatment for Clostridioides difficile, a large population of individuals infected will experience recurrence. In turn, fecal microbiota transplantation (FMT) has emerged as a promising treatment for recurrent C. difficile infection (rCDI). Mechanistically, by providing a healthy, diverse flora to the infected individual, FMT "resets" the underlying gut microbiome dysbiosis associated with rCDI. A proposed mechanism through which this occurs is via microbiome metabolites such as short-chain fatty acids (SCFAs); however, this has not been previously studied in pediatric patients. Using mass spectroscopy, we quantified pre- and post-transplant levels of acetate, isovalerate, butyrate, formate, and propionate in pediatric patients diagnosed with rCDI (n = 9). We compared pre- and post-transplant levels within the rCDI cohort at 1, 3, 6, and 12 months post-transplant and correlated these levels with healthy controls (n = 19). We witnessed a significant difference in the combined SCFA levels and the individual levels of acetate, butyrate, isovalerate, and propionate in the pre-treatment rCDI cohort compared to the healthy controls. In addition, there was a significant increase in combined SCFA levels at 12 months post-transplant within the rCDI group compared to that of their pre-transplant levels, and, more specifically, acetate, propionate, and isovalerate increased from pre-transplant to 12 months post-transplant. The longitudinal aspect of this study allowed us to identify mechanisms that contribute to the durability of responses to FMT, as well as characterize the unique patterns of short-chain fatty acid level recovery in rCDI pediatric patients.

A Multifaced Aspect of Clostridium difficile Infection in Pediatric Patients with Inflammatory Bowel Disease: Case Series and Literature Review

Children with inflammatory bowel disease (IBD) have an increased susceptibility to Clostridium difficile infection (CDI), with a rising incidence over time. Differentiating between CDI and IBD exacerbation is challenging due to overlapping symptoms. In our cohort of 55 pediatric IBD patients, 6 were diagnosed with CDI. Upon conducting a thorough patient evaluation and subsequent data analysis, an exhaustive review of the existing literature was undertaken. CDI is more prevalent in ulcerative colitis (UC) than Crohn's disease (CD) patients, as seen in our patients and in the existing literature. The management of a pediatric patient with IBD is itself a challenge for a clinician because of the chronic, possibly relapsing course, and substantial long-term morbidity. When CDI is added, it becomes even more demanding, since CDI leads to more severe disease in children with IBD. A multidisciplinary approach and intensive treatment for possible sepsis, anemia, hypoalbuminemia, and hydro-electrolytic and acid-base imbalances are frequently mandatory in patients with CDI and IBD, which leads to a significant health care burden in hospitalized children with IBD. After the infection is treated with antibiotic therapy, important considerations regarding the future treatment for the underlying IBD are also necessary; in most cases, a treatment escalation is required, as also seen in our study group.

Minimizing the risk of Clostridioides difficile infection as an early complication of autologous stem cell transplantation

This quality improvement project aimed to reduce institutional incidence of Clostridioides difficile infection (CDI) following autologous stem cell transplantation. CDI incidence per transplant was .17 in a baseline period and .09 following the implementation of postdischarge ultraviolet room cleaning (χ2 = 2.11, p = .15).

Predictors of Clostridium difficile infection after stoma reversal following TaTME surgery

BACKGROUND

 The aim of this study was to determine the incidence of Clostridium Difficile infection (CDI) after stoma reversal in patients who underwent transanal Total Mesorectal Excision (TaTME) and to evaluate variables correlated with this post-operative infection.

METHODS

 Patients who underwent stoma reversal surgery following TaTME for rectal cancer between 2015 and 2023 at a high-volume Institution, were retrospectively reviewed for the post-operative occurrence of diarrhea and in-hospital CDI (positive toxin in the stools). Patients were divided into the following subgroups according to the post-operative course: Group A-no clinical symptoms; Group B-mild diarrhea (< 10 evacuations/day); Group C-severe watery diarrhea (> 10 evacuations/day) with CDI negative; and Group D-severe watery diarrhea (> 10 evacuations/day) CDI positive. Clinical and laboratory data were analyzed for their correlation with CDI. A machine learning approach was used to determine predictors of diarrhea following stoma reversal.

RESULTS

 A total of 126 patients were selected, of whom 79 were assessed as Group A, 16 Group B, 25 Group C and 6 (4.8%) Group D. Univariable analysis documented that delayed stoma reversal correlated with CDI (Group A mean interval 44.6 weeks vs. Group D 68.4 weeks, p 0.01). The machine learning analysis confirmed the delay in stoma closure as a probability factor of presenting diarrhea; also, diarrhea probability was 80.5% in males, 77.8% in patients who underwent neoadjuvant therapy, and 63.9% in patients who underwent adjuvant therapy.

CONCLUSIONS

 Stoma reversal surgery can result in moderate rate of in-hospital CDI. Time-to stoma reversal is a crucial variable significantly related with this adverse outcome.

Role of probiotics in preventing Clostridioides difficile infection in older adults: an integrative review

Clostridioides difficile infection (CDI) is the leading cause of healthcare-associated diarrhea. This infection can particularly affect older adults, the most susceptible to CDI. Currently, the standard therapeutic measure is antibiotic therapy, which in turn increases the risk of recurrence of the infection by its collateral damage to the patient's microbiota. Probiotics are live microorganisms capable of maintaining balance in the intestinal microbiota. This study aims to perform an integrative review of the protective benefit of probiotics in CDI and diarrhea associated with C. difficile. The PubMed, Scopus, and Web of Science databases, the 10-year time cutoff, and the Prism Flow diagram were used for data collection. We observed no consensus among the studies; however, three of the seven evaluated studies demonstrated that the use of probiotics in older adults could contribute to reducing the incidence of hospital-onset CDI. We also found that the studies evaluated a wide variety of microorganisms, particularly Saccharomyces boulardii, associated with beneficial effects. More research is needed to understand the successful use of probiotics in the prevention of CDI in hospitalized older adults receiving antibiotics.

Proton pump inhibitors may enhance the risk of digestive diseases by regulating intestinal microbiota

Proton pump inhibitors (PPIs) are the most used acid-inhibitory drugs, with a wide range of applications in the treatment of various digestive diseases. However, recently, there has been a growing number of digestive complications linked to PPIs, and several studies have indicated that the intestinal flora play an important role in these complications. Therefore, developing a greater understanding of the role of the gut microbiota in PPI-related digestive diseases is essential. Here, we summarize the current research on the correlation between PPI-related digestive disorders and intestinal flora and establish the altered strains and possible pathogenic mechanisms of the different diseases. We aimed to provide a theoretical basis and reference for the future treatment and prevention of PPI-related digestive complications based on the regulation of the intestinal microbiota.

Clostridioides difficile resistance to antibiotics, including post-COVID-19 data

INTRODUCTION

Updating data on Clostridioides difficile antibiotic resistance is important for treatment improvement of C. difficile infections (CDIs).

AREAS COVERED

Results from 20 countries were included. The mean resistance to 2 mg/l vancomycin, 2 mg/l metronidazole, 4 mg/l moxifloxacin, and 4 mg/l clindamycin was 4.7% (0 to ≥ 26% in two studies), 2.6% (0 to ≥ 40% in 3 studies), 34.9% (6.6->80%), and 61.0% (30->90%), respectively. Resistance to erythromycin (>60-88%), rifampin (>23-55.0%), imipenem (0.6 to > 78% in a clone), tigecycline (0-<5.0%), and fidaxomicin (0-2%) was also found. Resistance to ≥ 5 antibiotics of different classes was reported in some countries. High resistance and multidrug resistance were observed in hypervirulent and epidemic strains. Although only 1% of COVID-19 patients had CDIs, the proportion might be underestimated.

EXPERT OPINION

C. difficile antimicrobial susceptibility varied by country/region, study period, and circulating ribotypes. For CDI treatment, fidaxomicin (preferably) or vancomycin is recommended, while metronidazole is suitable for mild infections. New approaches, including biotherapeutics (Rebyota), strains, antibiotics (ridinilazole and ibezapolstat), and monoclonal antibodies/cocktails merit further evaluation. Because of the resistance rate variations, C. difficile antibiotic susceptibility should be regularly monitored. Post-COVID-19 resistance should be separately presented. Some discrepancies between vancomycin and metronidazole results need to be clarified.

Treatment of recurrent Clostridioides difficile infections with faecal microbiota transplantation: peri-procedural methods in a consecutive case series

Background

Faecal microbiota transplantation (FMT) has high efficacy against recurrent Clostridioides difficile infection (CDI). Despite the increasing use of this therapy, the delay between diagnosis and treatment is excessive. Furthermore, donor selection is an important and time-consuming process.

Methods

We reviewed patients who underwent FMT for recurrent CDI at the CHU Charleroi Hospital between 2015 and 2022. The general context, type of administration, adverse events, and donor selection were reported. FMT was conducted using gastroduodenoscopy, colonoscopy, and enema with either fresh or frozen material.

Results

Ten patients with multiple comorbidities were treated by FMT. Seven patients were cured after one procedure. One patient was successfully cured after a change to an unrelated donor, and preliminary efficacy was established.

Conclusions

FMT is an effective treatment that should be considered during the earlier phases of treatment. Stool donors should be thoroughly screened for infectious diseases and other criteria related to microbiota composition.

An insight into Clostridioides difficile-associated diarrhea in Saudi children: diagnosis and treatment

INTRODUCTION

Clostridioides difficile infection (CDI) is a major cause for antibiotic-associated diarrhea. Specific factors put the pediatrics at risk. International guidelines lists specific recommendations for the diagnosis and treatment of pediatric CDI. The practice of diagnosing and treating pediatric CDI in Saudi Arabia is slightly different from the recommendations of the guidelines.

AREAS COVERED

This review summarizes pediatric CDI in Saudi Arabia in terms of epidemiology, current diagnostics, and how the practice compares to recommendations of the guidelines, and available treatment options.

EXPERT OPINION

Although pediatric CDI epidemiology in Saudi Arabia doesn't impose a burden on the healthcare system, it should be noted that not all hospitals follow CDI diagnostic recommendations of international guidelines, which may result in cases underreporting. However, due to the presumed low CDI prevalence, the traditional regimen of oral metronidazole for non-severe CDI remains effective, whereas vancomycin is used for severe cases. While fidaxomicin is approved for pediatrics, its high acquisition cost and low CDI rates make it challenging for hospitals to use it. Overall, pediatrics at risk of CDI recurrence should be evaluated, such as reviewing current antibiotics for potential discontinuation. Future studies evaluating the epidemiology and treatment for CDI in Saudi children are needed.

The RgaS-RgaR two-component system promotes Clostridioides difficile sporulation through a small RNA and the Agr1 system

The ability to form a dormant spore is essential for the survival of the anaerobic, gastrointestinal pathogen Clostridioides difficile outside of the mammalian gastrointestinal tract. The initiation of sporulation is governed by the master regulator of sporulation, Spo0A, which is activated by phosphorylation. Multiple sporulation factors control Spo0A phosphorylation; however, this regulatory pathway is not well defined in C. difficile. We discovered that RgaS and RgaR, a conserved orphan histidine kinase and orphan response regulator, function together as a cognate two-component regulatory system to directly activate transcription of several genes. One of these targets, agrB1D1, encodes gene products that synthesize and export a small quorum-sensing peptide, AgrD1, which positively influences expression of early sporulation genes. Another target, a small regulatory RNA now known as SrsR, impacts later stages of sporulation through an unknown regulatory mechanism(s). Unlike Agr systems in many organisms, AgrD1 does not activate the RgaS-RgaR two-component system, and thus, is not responsible for autoregulating its own production. Altogether, we demonstrate that C. difficile utilizes a conserved two-component system that is uncoupled from quorum-sensing to promote sporulation through two distinct regulatory pathways.

Assessing the Feasibility of Employing a Combination of a Bacteriophage-Derived Endolysin and Spore Germinants to Treat Relapsing Clostridioides difficile Infection

Clostridioides difficile is a Gram-positive, anaerobic, spore-forming bacillus and is a major cause of healthcare-associated infections. Whereas the vegetative form of the pathogen is susceptible to treatment with antibiotics, its ability to persist in the gut as antibiotic-resistant spores means that reinfection can occur in cases were the individual fails to re-establish a protective microflora. Bacteriophages and their lysins are currently being explored as treatment options due to their specificity, which minimizes the disruption to the other members of the gut microflora that are protective. The feasibility of employing recombinant endolysins to target the vegetative form of C. difficile has been demonstrated in animal models. In this study, we cloned and expressed the enzyme active domain of LysCD6356 and confirmed its ability to lyse the vegetative forms of a diverse range of clinical isolates of C. difficile, which included members of the hypervirulent 027 ribotype. Lytic activity was adversely affected by calcium, which is naturally found in the gut and is released from the spore upon germination. Our results suggests that a strategy in which the triggering of spore germination is separated in time from the application of the lysin could be developed as a strategy to reduce the risk of relapsing C. difficile infections.

Host Immunity and Immunization Strategies for Clostridioides difficile Infection

Clostridioides difficile infection (CDI) represents a significant challenge to public health. C. difficile-associated mortality and morbidity have led the U.S. CDC to designate it as an urgent threat. Moreover, recurrence or relapses can occur in up to a third of CDI patients, due in part to antibiotics being the primary treatment for CDI and the major cause of the disease. In this review, we summarize the current knowledge of innate immune responses, adaptive immune responses, and the link between innate and adaptive immune responses of the host against CDI. The other major determinants of CDI, such as C. difficile toxins, the host microbiota, and related treatments, are also described. Finally, we discuss the known therapeutic approaches and the current status of immunization strategies for CDI, which might help to bridge the knowledge gap in the generation of therapy against CDI.

Live fecal microbiota oral capsules (Vowst) for prevention of CDI recurrence

The FDA has approved Vowst (Seres Therapeutics/Nestle HealthScience), an oral capsule containing live fecal microbiota spores, for prevention of additional recurrences of Clostridioides difficile infection (CDI) in adults. Vowst is the first orally administered microbiota-based treatment to be approved for this indication.

Therapeutic Perspectives for Microbiota Transplantation in Digestive Diseases and Neoplasia-A Literature Review

In a mutually beneficial connection with its host, the gut microbiota affects the host's nutrition, immunity, and metabolism. An increasing number of studies have shown links between certain types of disease and gut dysbiosis or specific microorganisms. Fecal microbiota transplantation (FMT) is strongly advised for the treatment of recurrent or resistant Clostridium difficile infection (CDI) due to its outstanding clinical effectiveness against CDI. The therapeutic potential of FMT for other disorders, particularly inflammatory bowel diseases and malignancies, is currently gaining more and more attention. We summarized the most recent preclinical and clinical evidence to show the promise of FMT in the management of cancer as well as complications related to cancer treatment after reviewing the most recent research on the gut microbiota and its relationship to cancer.

The Novel DNA Binding Mechanism of Ridinilazole, a Precision Clostridiodes difficile Antibiotic

Clostridioides difficile infection (CDI) causes substantial morbidity and mortality worldwide with limited antibiotic treatment options. Ridinilazole is a precision bisbenzimidazole antibiotic being developed to treat CDI and reduce unacceptably high rates of infection recurrence in patients. Although in late clinical development, the precise mechanism of action by which ridinilazole elicits its bactericidal activity has remained elusive. Here, we present conclusive biochemical and structural data to demonstrate that ridinilazole has a primary DNA binding mechanism, with a co-complex structure confirming binding to the DNA minor groove. Additional RNA-seq data indicated early pleiotropic changes to transcription, with broad effects on multiple C. difficile compartments and significant effects on energy generation pathways particularly. DNA binding and genomic localization was confirmed through confocal microscopy utilizing the intrinsic fluorescence of ridinilazole upon DNA binding. As such, ridinilazole has the potential to be the first antibiotic approved with a DNA minor groove binding mechanism of action.

In Vitro Selection and Characterization of a DNAzyme Probe for Diverse Pathogenic Strains of Clostridium difficile

Clostridium difficile frequently causes an infectious disease known as Clostridium difficile infection (CDI) and there are urgent needs for the development of more effective rapid diagnostic tests for CDI. Previously we have developed an RNA-cleaving fluorogenic DNAzyme (RFD) probe named RFD-CD1, which is capable of detecting a specific strain of C. difficile but is too specific to recognize other pathogenic C. difficile strains. To overcome this issue, herein we report RFD-CD2, another RFD that is not only highly specific to C. difficile but also capable of recognizing diverse pathogenic C. difficile strains. Extensive sequence and structure characterization establishes a pseudoknot structure and a significantly minimized sequence for RFD-CD2. As a fluorescence sensor, RFD-CD2 can detect C. difficile at a concentration as low as 100 CFU/mL, making this DNAzyme an attractive molecular probe for rapid diagnosis of CDI caused by diverse strains of C. difficile.

Managing infection prevention and control in the emergency care setting: an overview for emergency nurses

The control and prevention of infection in emergency departments (EDs) remains challenging because of the complexity of the environment and the consistently high attendance in many EDs. Emergency nurses play an essential role in infection prevention and control in this clinical area. The COVID-19 pandemic has refocused the need for emergency nurses to have a good knowledge and understanding of infection control processes and the clinical skills to protect themselves and patients alike. This article provides an overview of UK epidemiological perspectives, the main pathogens associated with healthcare infections, the importance of reducing pathogen transmission and the emergency nurse's role in antibiotic stewardship.

Faecal Microbiota Transplantation is a simple, effective and safe treatment in the management of C. difficile infection in daily clinical practice

INTRODUCTION

Faecal microbiota transplantation (FMT) is a treatment supported by wide scientific evidence and proved to be very effective in the management of Clostridioides difficile infection (CDI). The objective of this study is to analyze its effectiveness and safety in a real clinical practice setting.

METHODS

Retrospective, single-center and descriptive observational study in which all FMT performed between May 2016 and December 2020 were included. Technical success was defined as the successful administration of the faecal preparation in the patient's gastrointestinal tract and clinical success the disappearance of diarrhoea in the first 72 h after the procedure with no relapse within the following 8 weeks after the therapy was started.

RESULTS

15 FMT were performed in 13 patients. Median age was 79 years (range: 40-98 years); being 60% women and 33.3% depedent persons. The indication for FMT was recurrent CDI in 84.6%. All FMTs were performed by colonoscopy and from related donors. With a first procedure, the FMT was effective in 11 of 13 patients (84.61%; 95% CI; 54.55-98.07). Time until resolution of symptoms was less than 48 h in all cases. Post-transplant follow-up was 25.66 ± 17.5 months. No significant short or long-term complications were recorded at follow-up.

CONCLUSION

TMF is a simple, effective and safe procedure in CD infection, even in elderly patients or those with great comorbidities.

Gene network interaction analysis to elucidate the antimicrobial resistance mechanisms in the Clostridiumdifficile

Antimicrobial resistance has caused chaos worldwide due to the depiction of multidrug-resistant (MDR) infective microorganisms. A thorough examination of antimicrobial resistance (AMR) genes and associated resistant mechanisms is vital to solving this problem. Clostridium difficile (C. difficile) is an opportunistic nosocomial bacterial strain that has acquired exogenous AMR genes that confer resistance to antimicrobials such as erythromycin, azithromycin, clarithromycin, rifampicin, moxifloxacin, fluoroquinolones, vancomycin, and others. A network of interactions, including 20 AMR genes, was created and analyzed. In functional enrichment analysis, Cellular components (CC), Molecular Functions (MF), and Biological Processes (BP) were discovered to have substantial involvement. Mutations in the rpl genes, which encode ribosomal proteins, confer resistance in Gram-positive bacteria. Full erythromycin and azithromycin cross-resistance can be conferred if more than one of the abovementioned genes is present. In the enriched BP, rps genes related to transcriptional regulation and biosynthesis were found. The genes belong to the rpoB gene family, which has previously been related to rifampicin resistance. The genes rpoB, gyrA, gyrB, rpoS, rpl genes, rps genes, and Van genes are thought to be the hub genes implicated in resistance in C. difficile. As a result, new medications could be developed using these genes. Overall, our observations provide a thorough understanding of C. difficile AMR mechanisms.

Clostridium difficile toxins impact on rat colon smooth muscle reactivity

AIM

The present study was conducted in an attempt to find possible direct mechanisms of action of Clostridium difficile toxins A and B (TCdA and TCdB) on contractility of isolated rat intestinal smooth muscles, as the contractive pathways affected by the toxins and responsible for motility disorders remain unclear.

MATERIALS AND METHODS

Adult male Wistar rats were used in our experiments. Longitudinal smooth muscle (SM) preparations of proximal colon were isolated and their contractile activity was isometrically registered. The samples were mounted in tissue baths and exogenously treated with acetylcholine (ACh), serotonin (5-HT), dopamine, norepinephrine, TCdA and TCdB. The potential of TCdA and TCdB to affect the action of these mediators on SM activity was examined.

RESULTS

The experiments have shown that exciting action of ACh and 5-HT on colonic contractility is enhanced by TCdA rather than TCdB. Conversely, relaxing effect of dopamine and norepinephrine on contractile activity of colonic SM is under impact of TCdB but not TcdA. TCdA has a stronger direct effect on in vitro SM sensitivity to ACh and 5-HT than TCdB.

CONCLUSIONS

TCdA and TCdB affect directly the contractile reactivity of isolated rat colon smooth muscle. TCdA has a stronger direct effect on smooth muscle sensitivity to acetylcholine and 5-HT than TCdB. Such a trend has not been established for dopamine and norepinephrine.

Is Increased BMI a Risk Factor for Developing Severe Clostridioides Difficile Infection? A Retrospective Study

Background

Obesity is associated with a relative increase in bacterial phyla like firmicutes, which helps in the colonization of Clostridioides Difficile.

Hypothesis

Individuals with increased BMI (greater than 25) are more susceptible to severe Clostridioides Difficile infection (CDI).

Methods

Data was collected by retrospective chart query. Severe CDI was defined as a white blood cell count of more than 15,000 (x 109 cells/L) or serum creatinine levels greater than 1.5 mg/dL. To examine the association between the primary outcome (severe CDI) and BMI, the factors of age, gender, albumin level, ICU admission, antibiotic use within 3 months of admission, diabetes, and hypertension were also considered. Patients with chronic kidney disease, end-stage liver disease, pregnancy, inflammatory bowel disease, previous gastrointestinal surgeries, active malignancy, and immunosuppressed were excluded.

Results

219 patients were included in the final study. Of these 52.8% of patients had severe CDI, and 47.2% had non-severe CDI. Compared to normal-weight patients, risk of severe CDI was not influenced by being obese (OR = 1.26, p = 0.5119), overweight (OR = 1.65, p = 0.21), or underweight (OR = 1.05, p = 0.9383). Males had higher odds of having severe CDI when compared with females (OR = 1.76, 95% CI = 1.03 to 3.01, p = 0.0395). Albumin levels greater than 3.0 mg/dL were associated with lower odds of having severe CDI (OR = 0.41, 95% CI = 0.27 to 0.62, p< 0.0001).

Conclusion

BMI of an individual does not appear to be associated with the severity of CDI.

Polysaccharide II Surface Anchoring, the Achilles' Heel of Clostridioides difficile

Cell wall glycopolymers (CWPGs) in Gram-positive bacteria have been reported to be involved in several bacterial processes. These polymers, pillars for proteins and S-layer, are essential for the bacterial surface setup, could be essential for growth, and, in pathogens, participate most often in virulence. CWGPs are covalently anchored to peptidoglycan by proteins that belong to the LytR-CpsA-PSr (LCP) family. This anchoring, important for growth, was reported as essential for some bacteria such as Bacillus subtilis, but the reason why CWGP anchoring is essential remains unknown. We studied LcpA and LcpB of Clostridioides difficile and showed that they have a redundant activity. To delete both lcp genes, we set up the first conditional-lethal mutant method in C. difficile and showed that polysaccharide II (PSII) anchoring at the bacterial surface is essential for C. difficile survival. In the conditional-lethal mutant, C. difficile morphology was impaired, suggesting that peptidoglycan synthesis was affected. Because Lcp proteins are transferring CWPGs from the C55-undecaprenyl phosphate (also needed in the peptidoglycan synthesis process), we assumed that there was competition between PSII and peptidoglycan synthesis pathways. We confirmed that UDP-MurNAc-pentapeptide precursor was accumulated, showing that peptidoglycan synthesis was blocked. Our results provide an explanation for the essentiality of PSII anchoring in C. difficile and suggest that the essentiality of the anchoring of CWPGs in other bacteria can also be explained by the blocking of peptidoglycan synthesis. To conclude, our results suggest that Lcps are potential new targets to combat C. difficile infection. IMPORTANCE Cell wall glycopolymers (CWGPs) in Gram-positive bacteria have been reported to be involved in several bacterial processes. CWGP anchoring to peptidoglycan is important for growth and virulence. We set up the first conditional-lethal mutant method in Clostridioides difficile to study LcpA and LcpB involved in the anchoring of CWPGs to peptidoglycan. This study offers new tools to reveal the role of essential genes in C. difficile. LcpA and LcpB activity was shown to be essential, suggesting that they are potential new targets to combat C. difficile infection. In this study, we also showed that there is competition between the polysaccharide II synthesis pathway and peptidoglycan synthesis that probably exists in other Gram-positive bacteria. A better understanding of these mechanisms allows us to define the Lcp proteins as a therapeutic target for potential design of novel antibiotics against pathogenic Gram-positive bacteria.

Two-step algorithm-based Clostridioides difficile testing as a tool for antibiotic stewardship

OBJECTIVES

Diagnosis of Clostridium difficile infection (CDI) can be challenging due to high colonization rates. Unlike PCR-only testing, two-step algorithm testing (that includes toxin and PCR) may help differentiate colonization from active infection, but it is unknown if this type of testing impacts treatment decisions. We examined the association between changing CDI diagnostic methods, the way the testing results were displayed, and the rates of CDI-specific treatment.

METHODS

We performed a retrospective analysis of positive C. difficile cases over 2 years, a year preceding and following our institution's transition from PCR to two-step testing. During the PCR period, results were displayed in the electronic medical record as 'positive'. In the two-step period, positive results were either displayed as 'likely colonized' or 'toxin positive'. Rates of CDI-specific therapy and adverse patient outcomes (30-day mortality and intensive care unit admission) were compared among the three groups.

RESULTS

A total of 610 patients had positive results over the study period. Of the 354 patients in the PCR group, 329 (93%) were treated with CDI-specific therapy. Of the 142 patients in the likely colonized group, 59 (42%) were treated. All 114 patients in the toxin-positive group were treated. Multivariate analysis of patients who were PCR positive or likely colonized showed that tests sent in the two-step era were less likely to be associated with treatment for CDI (odds ratio 0.05, 95% CI 0.03-0.09).

DISCUSSION

We found a correlation between changing the type of test and the way the results were displayed and reduction in CDI-specific antibiotic use without restricting clinician diagnostic ordering.

Abdominal aortic endograft infection with Clostridium difficile

OBJECTIVES

The increase in endovascular aortic aneurysm repair has led to increasing incidence of aortic endograft infections. Additionally, more atypical organisms are being identified as pathogens. We report on a rare aortic endograft infection to further characterize and understand these infections.

METHODS

We report a Clostridium difficile culture-positive aortic endograft infection in an 82-year-old male 3 years after endovascular abdominal aortic aneurysm repair.

RESULTS

The patient underwent successful open, complete explant of his endograft and in-situ repair using a rifampin-soaked Dacron graft. He continues to do well.

CONCLUSIONS

Aortic endograft infections are a complex problem further complicated by rare and virulent infections. Unless the patient is at prohibitive risk, the management of infected aortic endografts is surgical graft explant and in-situ or extra-anatomic reconstruction due to the exceedingly high mortality rate with non-operative management.

Final Results from a Phase 2b Randomized, Placebo-Controlled Clinical Trial of RBX2660: A Microbiota-Based Drug for the Prevention of Recurrent Clostridioides difficile Infection

INTRODUCTION

Effective treatments for recurrent Clostridioides difficile infection (rCDI) are urgently needed. RBX2660 is an investigational microbiota-based live biotherapeutic to reduce CDI recurrence following standard-of-care antibiotic treatment in individuals with rCDI. Here we report the final safety data through 24 months of follow-up as well as final efficacy data, reflecting alignment of the pre-specified statistical analysis plan definitions with the data presented.

METHODS

The PUNCH CD2 clinical trial was a prospective, multicenter, randomized, double-blinded, placebo-controlled, three-arm phase 2b study conducted to evaluate the efficacy and safety of RBX2660 for the reduction of rCDI compared to placebo. Eligible patients were at least 18 years of age and had at least three episodes of CDI and at least two rounds of standard antibiotic treatment or had at least two episodes of severe CDI resulting in hospitalization. Patients were randomized 1:1:1 to group A, two doses of RBX2660; group B, two doses of placebo; or group C, one dose of RBX2660 and one dose of placebo; all administered 7 ± 2 days apart. Treatment success was prevention of recurrence, defined as absence of diarrhea and no re-treatment for CDI any time after the first dose until 8 weeks after the second dose of the study treatment. Safety was assessed by reports of adverse events and symptoms. The final efficacy and safety are reported for data available through 24 months.

RESULTS

For the primary endpoint, treatment success at 8 weeks, 56.8% (25/45) of participants who received one dose of RBX2660 + one dose of placebo, 55.6% (25/45) of participants who received two doses of RBX2660, and 43.2% (19/44) of participants who received two doses of placebo in the final intention-to-treat (ITT) population were responders (both p = 0.2 vs placebo). In the per-protocol population, 87.5% (21/24) of participants who received one dose of RBX2660 + one dose of placebo and 58.1% (18/31) of those who received two doses of placebo had treatment success (p = 0.017; treatment difference, 29.4 [95% CI 7.6, 51.3]); 75.0% (21/28) of participants in the PP population who received two doses of RBX2660 were responders (p = 0.17 vs placebo). The safety profile of RBX2660, whether delivered as one or two doses, was similar to the placebo group.

CONCLUSION

While the phase 2b PUNCH CD2 clinical trial did not meet its pre-defined primary endpoint of treatment success at 8 weeks after two doses of RBX2660 vs two doses of placebo, clinically meaningful data were obtained to justify proceeding with the single dose regimen in the phase 3 clinical trial, PUNCH CD3, now complete. To date, the cumulative data for RBX2660 demonstrate consistent efficacy and safety outcomes for reduction of CDI recurrence in adults.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov: NCT02299570.

Time to Place Clostridium difficile Infections in Major Healthcare-associated Infections List

How to cite this article: Sinha S, Behera S. Time to Place Clostridium difficile Infections in Major Healthcare-associated Infections List. Indian J Crit Care Med 2023;27(2):152-153.