Clinical, epidemiological and microbiological characteristics of relapse and re-infection in Clostridium difficile infection

Recurrence of Clostridioides difficile infection and mortality in older inpatients

PURPOSE

The prevalence of Clostridioides difficile infection in older and frail population is extremely high and adverse outcomes, including future recurrences and premature mortality, are common. Nonetheless, the clinical risk profile for Clostridioides difficile recurrence in older people is still controversial. We aimed to investigate: 1) the association between Clostridioides difficile recurrence and 6-month mortality; 2) the risk factors for Clostridioides difficile recurrence after hospital discharge.

METHODS

This is a retrospective study on adults with a first episode of Clostridioides difficile infection admitted to all Internal Medicine and Geriatrics Units of the University Hospital of Ferrara (Italy) between January 2018 and December 2020. For each patient, sociodemographic, clinical and laboratory data were collected through hospital database system. The primary and secondary outcomes were mortality and recurrence within 6 months from the first infectious episode, respectively.

RESULTS

The mean age of the 386 enrolled patients was 77.8 years; 61.7% were females. Twelve percent patients had Clostridioides difficile recurrence and 32.1% patients died during the 6-month follow-up. At Cox analysis, after adjustment for the potential confounders, participants with recurrence reported a twofold risk of death compared to those without recurrence (HR, 95% CI 2.45, 1.59-3.78). Compared to patients treated with metronidazole, those treated with vancomycin showed a lower risk of recurrence (log-rank p < 0.001).

CONCLUSION

Clostridioides difficile recurrence is associated with a higher risk of mortality and it may itself be a marker of frailty and vulnerability. Vancomycin treatment during the infectious episode was associated with lower recurrence rate, as compared to metronidazole.

Clostridioides difficile recurrence in individuals with and without cancer: a Swedish population-based cohort study

PURPOSE

Patients with cancer are vulnerable to Clostridioides difficile infection (CDI) due to their disease, treatment and regular hospital contact, yet if CDI-recurrence is more common remains unclear, and differences among cancer types remain unexplored.

METHODS

This Swedish nationwide population-based cohort included all 43,150 individuals with recorded CDI (2006-2019) to assess CDI-recurrence in individuals with and without cancer, with binary multivariable logistic regression, stratified by anatomical location, and survival status.

RESULTS

Compared to those without cancer (N = 29,543), ongoing cancer (diagnosis < 12 months; N = 3,882) was associated with reduced recurrence (OR = 0.81, 95% CI 0.73-0.89), while there was no association with cancer history (diagnosis ≥ 12 months; N = 9,725). There was an increased 8-week all-cause mortality (Ongoing cancer: OR = 1.58, 95% CI 1.43-1.74; Cancer history: OR = 1.45, 95% CI 1.36-1.55) compared to those without cancer. Among CDI-survivors, those with ongoing cancer presented with a decreased odds of recurrence (OR = 0.84, 95% CI 0.76-0.94), compared to those without cancer history, with no association for those with cancer history (OR = 1.04, 95% CI 0.97-1.1). Large variations were seen across cancer types, with the highest observed proportion of recurrence in oral and mesothelial cancer, and the lowest for esophageal cancer, although no statistically significant OR were found.

CONCLUSION

The population-based study indicates that individuals with cancer may have fewerrecurrences than expected, yet variations by cancer type were large, and mortality was high.

Pathogenicity and virulence of Clostridioides difficile

Clostridioides difficile is the most common cause of nosocomial antibiotic-associated diarrhea, and is responsible for a spectrum of diseases characterized by high levels of recurrence, morbidity, and mortality. Treatment is complex, since antibiotics constitute both the main treatment and the major risk factor for infection. Worryingly, resistance to multiple antibiotics is becoming increasingly widespread, leading to the classification of this pathogen as an urgent threat to global health. As a consummate opportunist, C. difficile is well equipped for promoting disease, owing to its arsenal of virulence factors: transmission of this anaerobe is highly efficient due to the formation of robust endospores, and an array of adhesins promote gut colonization. C. difficile produces multiple toxins acting upon gut epithelia, resulting in manifestations typical of diarrheal disease, and severe inflammation in a subset of patients. This review focuses on such virulence factors, as well as the importance of antimicrobial resistance and genome plasticity in enabling pathogenesis and persistence of this important pathogen.

Trends in and Risk Factors for Recurrent Clostridioides difficile Infection, New Haven County, Connecticut, USA, 2015-2020

Recurrent Clostridioides difficile infection (RCDI) causes an increased burden on the healthcare system. We calculated RCDI incidence and identified factors associated with RCDI cases in New Haven County, Connecticut, USA, during 2015-2020 by using data from population-based laboratory surveillance. A subset of C. difficile cases had complete chart reviews conducted for RCDI and potentially associated variables. RCDI was defined as a positive C. difficile specimen occurring 2-8 weeks after incident C. difficile infection. We compared cases with and without RCDI by using multiple regression. RCDI occurred in 12.0% of 4,301 chart-reviewed C. difficile cases, showing a U-shaped time trend with a sharp increase in 2020, mostly because of an increase in hospital-onset cases. Malignancy (odds ratio 1.51 [95% CI 1.11-2.07]) and antecedent nitrofurantoin use (odds ratio 2.37 [95% CI 1.23-4.58]) were medical risk factors for RCDI. The 2020 increase may reflect the impact of the COVID-19 pandemic.

Clostridioides difficile infection: traversing host-pathogen interactions in the gut

C. difficile is the primary cause for nosocomial infective diarrhoea. For a successful infection, C. difficile must navigate between resident gut bacteria and the harsh host environment. The perturbation of the intestinal microbiota by broad-spectrum antibiotics alters the composition and the geography of the gut microbiota, deterring colonization resistance, and enabling C. difficile to colonize. This review will discuss how C. difficile interacts with and exploits the microbiota and the host epithelium to infect and persist. We provide an overview of C. difficile virulence factors and their interactions with the gut to aid adhesion, cause epithelial damage and mediate persistence. Finally, we document the host responses to C. difficile, describing the immune cells and host pathways that are associated and triggered during C. difficile infection.

Rate and predictors of 30-day readmission for clostridiodes difficile: a United States analysis

BACKGROUND

Clostridiodes difficile is a leading cause of healthcare-associated diarrhea. In this study, we aimed to identify the rates and predictors for 30-day readmissions of Clostridiodes difficile Enterocolitis (CDE) in the United States.

METHODS

We conducted a retrospective study of the Nationwide Readmissions Database to identify adult hospitalizations with a principal diagnosis of CDE for 2018. Individuals <18 years old and elective hospitalizations were excluded. Primary outcomes included readmission rate and the top ten principal diagnosis on readmission, while the secondary outcomes were inpatient mortality, hospital costs and independent predictors of 30-day all-cause readmissions. Furthermore, we devised a scoring system to estimate the risk of CDE readmissions. Stata® Version 16 was used for statistical analysis and p-values ≤0.05 were statistically significant.

RESULTS

We identified 94,668 index hospitalizations and 18,296 readmissions at 30-days for CDE in 2018. The 30-day all-cause readmission rate was 25.7%. On readmission, CDE was the most common principal diagnosis (25.7%), followed by unspecified sepsis, and acute renal failure. A female predominance was also noted for index and 30-day readmissions of CDE. Compared to index admissions, we noted higher odds of inpatient mortality [4.4 vs 1.4%, Odds Ratio (OR):3.32, 95% Confidence Interval (CI):2.87-3.84, p < 0.001], longer mean length of stay (LOS) [6.4 vs 5.6 days, Mean Difference (MD):0.9, 95% CI:0.7-1.0, p < 0.001), and higher mean total hospital charge (THC) [$56,015 vs $40,871, MD:15,144, 95% CI:13,260-17,027, p < 0.001] for 30-day readmissions of CDE. Independent predictors for 30-day all-cause readmissions of CDE included discharged against medical advice (AMA) [Adjusd Hazard Ratio (aHR):2.01, 95% CI:1.73-2.53, p < 0.001], diabetes mellitus (DM) [aHR:1.22, 95% CI:1.16-1.29, p < 0.001], and chronic kidney disease (CKD) [aHR:1.29, 95% CI:1.21-1.37, p < 0.001].

CONCLUSION

The all-cause 30-day readmission rate and inpatient mortality for CDE was 25.7% and 4.4%, respectively. Discharge AMA, DM and CKD were independent predictors for 30-day all-cause readmissions of CDE.KEY MESSAGEThe 30-day all-cause readmission rate for Clostridiodes difficile Enterocolitis was noted to be 21.4% in 2018.Independent predictors of 30-day all-cause readmissions for Clostridiodes difficile Enterocolitis include diabetes mellitus, discharged against medical advice and chronic kidney disease.Readmissions of Clostridiodes difficile Enterocolitis had higher mortality rates, healthcare cost and length of hospital stay compared to index admissions.

Clostridioides difficile Spore Formation and Germination: New Insights and Opportunities for Intervention

Spore formation and germination are essential for the bacterial pathogen Clostridioides difficile to transmit infection. Despite the importance of these developmental processes to the infection cycle of C. difficile, the molecular mechanisms underlying how this obligate anaerobe forms infectious spores and how these spores germinate to initiate infection were largely unknown until recently. Work in the last decade has revealed that C. difficile uses a distinct mechanism for sensing and transducing germinant signals relative to previously characterized spore formers. The C. difficile spore assembly pathway also exhibits notable differences relative to Bacillus spp., where spore formation has been more extensively studied. For both these processes, factors that are conserved only in C. difficile or the related Peptostreptococcaceae family are employed, and even highly conserved spore proteins can have differential functions or requirements in C. difficile compared to other spore formers. This review summarizes our current understanding of the mechanisms controlling C. difficile spore formation and germination and describes strategies for inhibiting these processes to prevent C. difficile infection and disease recurrence.

Clostridioides difficile Single Cell Swimming Strategy: A Novel Motility Pattern Regulated by Viscoelastic Properties of the Environment

Flagellar motility is important for the pathogenesis of many intestinal pathogens, allowing bacteria to move to their preferred ecological niche. Clostridioides difficile is currently the major cause for bacterial health care-associated intestinal infections in the western world. Most clinical strains produce peritrichous flagella and are motile in soft-agar. However, little knowledge exists on the C. difficile swimming behaviour and its regulation at the level of individual cells. We report here on the swimming strategy of C. difficile at the single cell level and its dependency on environmental parameters. A comprehensive analysis of motility parameters from several thousand bacteria was achieved with the aid of a recently developed bacterial tracking programme. C. difficile motility was found to be strongly dependent on the matrix elasticity of the medium. Long run phases of all four motile C. difficile clades were only observed in the presence of high molecular weight molecules such as polyvinylpyrrolidone (PVP) and mucin, which suggests an adaptation of the motility apparatus to the mucin-rich intestinal environment. Increasing mucin or PVP concentrations lead to longer and straighter runs with increased travelled distance per run and fewer turnarounds that result in a higher net displacement of the bacteria. The observed C. difficile swimming pattern under these conditions is characterised by bidirectional, alternating back and forth run phases, interrupted by a short stop without an apparent reorientation or tumbling phase. This motility type was not described before for peritrichous bacteria and is more similar to some previously described polar monotrichous bacteria.

[Clostridium difficile infection and its susceptibility factors in children with inflammatory bowel disease]

OBJECTIVE

To investigate the incidence rates of Clostridium difficile colonization and Clostridium difficile infection (CDI) in children with inflammatory bowel disease (IBD) and the susceptibility factors for CDI in children with IBD.

METHODS

A total of 62 children diagnosed with IBD were enrolled as the IBD group. Forty-two children who attended the hospital due to persistent or chronic diarrhea and were excluded from IBD were enrolled as the non-IBD group. The incidence rate of CDI was compared between the two groups. According to the presence or absence of CDI, the IBD group was subdivided into two groups:IBD+CDI (n=12) and non-CDI IBD (n=50), and the clinical data were collected from the two groups to analyze the susceptibility factors for CDI.

RESULTS

The IBD group had a significantly higher incidence rate of CDI[19% (12/62) vs 2% (1/42); P < 0.05] than the non-IBD group (P < 0.05). Compared with the non-CDI IBD group, the IBD+CDI group had a significantly longer disease course (P < 0.05), and a significantly higher proportion of children with fever, diarrhea, or abdominal pain (P < 0.05). The IBD+CDI group had significantly higher activity indices of pediatric Crohn's disease, C-reactive protein levels and erythrocyte sedimentation rate than the non-CDI IBD group (P < 0.05). The univariate analysis showed that compared with the non-CDI IBD group, the IBD+CDI group had a significantly higher proportion of children with moderate-to-severe disease, use of glucocorticoids, or treatment with broad-spectrum antibiotics for more than 14 days before diagnosis (P < 0.05).

CONCLUSIONS

The children with IBD have a higher incidence of CDI than those without IBD. Severe disease conditions and use of broad-spectrum antibiotics or glucocorticoids may be associated with an increased incidence of CDI in children with IBD.

What's a Biofilm?-How the Choice of the Biofilm Model Impacts the Protein Inventory of Clostridioides difficile

The anaerobic pathogen Clostridioides difficile is perfectly equipped to survive and persist inside the mammalian intestine. When facing unfavorable conditions C. difficile is able to form highly resistant endospores. Likewise, biofilms are currently discussed as form of persistence. Here a comprehensive proteomics approach was applied to investigate the molecular processes of C. difficile strain 630Δerm underlying biofilm formation. The comparison of the proteome from two different forms of biofilm-like growth, namely aggregate biofilms and colonies on agar plates, revealed major differences in the formation of cell surface proteins, as well as enzymes of its energy and stress metabolism. For instance, while the obtained data suggest that aggregate biofilm cells express both flagella, type IV pili and enzymes required for biosynthesis of cell-surface polysaccharides, the S-layer protein SlpA and most cell wall proteins (CWPs) encoded adjacent to SlpA were detected in significantly lower amounts in aggregate biofilm cells than in colony biofilms. Moreover, the obtained data suggested that aggregate biofilm cells are rather actively growing cells while colony biofilm cells most likely severely suffer from a lack of reductive equivalents what requires induction of the Wood-Ljungdahl pathway and C. difficile’s V-type ATPase to maintain cell homeostasis. In agreement with this, aggregate biofilm cells, in contrast to colony biofilm cells, neither induced toxin nor spore production. Finally, the data revealed that the sigma factor SigL/RpoN and its dependent regulators are noticeably induced in aggregate biofilms suggesting an important role of SigL/RpoN in aggregate biofilm formation.

Predictors of Clostridioides difficile Infection Among Asymptomatic, Colonized Patients: A Retrospective Cohort Study

BACKGROUND

Asymptomatic patients colonized with Clostridioides difficile are at risk of developing C. difficile infection (CDI), but the factors associated with disease onset are poorly understood. Our aims were to identify predictors of hospital-onset CDI (HO-CDI) among colonized patients and to explore the potential benefits of primary prophylaxis to prevent CDI.

METHODS

We conducted a retrospective cohort study in a tertiary academic institution. Colonized patients were identified by detecting the tcdB gene by polymerase chain reaction on a rectal swab. Univariate and multivariate logistic regression analyses were used to identify predictors of HO-CDI.

RESULTS

There were 19 112 patients screened, from which 960 (5%) colonized patients were identified: 513 met the inclusion criteria. Overall, 39 (7.6%) developed a HO-CDI, with a 30-day attributable mortality of 15%. An increasing length of stay (adjusted odds ratio [aOR] per day, 1.03; P = .006), exposure to multiple classes of antibiotics (aOR per class, 1.45; P = .02), use of opioids (aOR, 2.78; P = .007), and cirrhosis (aOR 5.49; P = .008) were independently associated with increased risks of HO-CDI, whereas the use of laxatives was associated with a lower risk of CDI (aOR 0.36; P = .01). Among the antimicrobials, B-lactam with B-lactamase inhibitors (OR 3.65; P < .001), first-generation cephalosporins (OR 2.38; P = .03), and carbapenems (OR 2.44; P = .03) correlated with the greatest risk of HO-CDI. By contrast, patient age, the use of proton pump inhibitors, and the use of primary prophylaxis were not significant predictors of HO-CDI.

CONCLUSIONS

This study identifies several factors that are associated with CDI among colonized patients. Whether modifying these variables could decrease the risk of CDI should be investigated.

Severe Clostridium difficile infection with extremely high leucocytosis complicated by a concomitant bloodstream infection caused by Klebsiella pneumoniae after osteomyelitis surgery: A case report

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Exposure to antibiotics after surgery increase risk of Cl. difficile infection.

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Sudden high leucocytosis may be sign of poor outcome in Cl. difficile case.

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Oral Vancomycin could be responsible for the growth of bloodstream Kl. pneumonia.

Introduction

Clostridium difficile is one of the most common healthcare-associated infections. Pseudomembranous colitis is a serious complication of Clostridium difficile infection (CDI) after septic surgery and antibacterial therapy. A sudden white blood cell (WBC) count increase and extremely high leucocytosis may be a predictor of a poor outcome.

Presentation of case

A 77 years old male was hospitalised because of lower leg osteomyelitis and was operated. He received antibacterial treatment with Cefazolin for three days and then developed a high WBC count. The course of the disease was fulminant, with a rapid increase in the WBC count up to 132,000/mm³ and a septic shock, and required cardiovascular and ventilatory support. The patient was started on intravenous Metronidazole (500 mg every eight hours) and oral Vancomycin (500 mg every six hours). The patient’s condition gradually improved over a period of six days. Then a hyperthermia above 39 degrees Celsius, hypotension and painful abdominal bloating developed, and the WBC count peaked to 186,000/mm³. The blood cultures were positive for Klebsiella pneumoniae. The patient died.

Discussion

In our case, we describe a community-onset, healthcare-facility-associated, severe CDI complicated by a blood stream infection. The administration of oral Vancomycin, which is highly active against the intestinal flora, could have been responsible for the persistence and overgrowth of Klebsiella pneumoniae.

Conclusions

Severe CDIs after orthopaedic surgery and antibacterial treatment complicated by the development of nosocomial infection significantly worsen the prognosis of the disease. Careful consideration of antibacterial therapy and early symptom recognition may help prevent catastrophic events.

Risk of complications and mortality following recurrent and non-recurrent Clostridioides difficile infection: a retrospective observational database study in England

BACKGROUND

Clostridioides difficile infection (CDI) increases the risk of complications and mortality. We assessed the magnitude of these outcomes in a large cohort of English patients with initial and recurrent CDI.

AIM

To compare the risk of complications and all-cause mortality, within 12 months, among hospitalized patients ≥18 years old with hospital-associated- (HA-) CDI and recurrent CDI.

METHODS

Patients with HA-CDI during 2002-2013 were identified using inpatient hospital data linked to primary care and death data. Each HA-CDI case was frequency matched to two hospitalized patients without CDI on age group, sex, calendar year of admission, admission method and number of hospital care episodes. A second CDI episode starting on days 13-56 was defined as recurrence. Risks of mortality and complications at 12 months were analysed using Cox proportional hazard models.

FINDINGS

We included 6862 patients with HA-CDI and 13,724 without CDI. Median age was 81.0 years (IQR 71.0-87.0). Patients with HA-CDI had more comorbidities than those without CDI, and significantly higher risks of mortality (adjusted hazard ratio (95% confidence interval) 1.77 (1.67-1.87)) and complications (1.66 (1.46-1.88)) within 12 months from hospital admission. Of those with HA-CDI, 1140 (16.6%) experienced CDI recurrence. Patients with recurrent versus non-recurrent CDI also had significantly increased risk of mortality (1.32 (1.20-1.45)) and complications (1.37 (1.01-1.84)) in the 12 months from the initial CDI.

CONCLUSIONS

HA-CDI (versus no CDI) and recurrent CDI are both associated with significantly higher risks of complications or death within 12 months of the initial CDI episode.

Human C. difficile toxin-specific memory B cell repertoires encode poorly neutralizing antibodies

Clostridioides difficile is a leading cause of nosocomial infection responsible for significant morbidity and mortality with limited options for therapy. Secreted C. difficile toxin B (TcdB) is a major contributor to disease pathology, and select TcdB-specific Abs may protect against disease recurrence. However, the high frequency of recurrence suggests that the memory B cell response, essential for new Ab production following C. difficile reexposure, is insufficient. We therefore isolated TcdB-specific memory B cells from individuals with a history of C. difficile infection and performed single-cell deep sequencing of their Ab genes. Herein, we report that TcdB-specific memory B cell-encoded antibodies showed somatic hypermutation but displayed limited isotype class switch. Memory B cell-encoded mAb generated from the gene sequences revealed low to moderate affinity for TcdB and a limited ability to neutralize TcdB. These findings indicate that memory B cells are an important factor in C. difficile disease recurrence.

The gut microbiome diversity of Clostridioides difficile-inoculated mice treated with vancomycin and fidaxomicin

OBJECTIVE

To investigate the effect of vancomycin and fidaxomicin on the diversity of intestinal microbiota in a mouse model of Clostridioides difficile infection.

METHODS

Mice were divided into 11 models (4 mice per model): 6 uninoculated models and 5 models inoculated with C. difficile BI/NAP1/027. Inoculated models were prepared using intraperitoneal clindamycin followed by inoculation with C. difficile BI/NAP1/027. Uninoculated and C. difficile-inoculated mice received 2 or 7 days' vancomycin or fidaxomicin. Clostridium butyricum MIYAIRI 588 probiotic and lactoferrin prebiotic were administered for 10 days to uninoculated mice. Intestinal microbiome composition was investigated by sequence analyses of bacterial 16S rRNA genes from faeces, and microbiota diversity estimated.

RESULTS

In uninoculated, untreated ('normal') mice, Clostridia (57.8%) and Bacteroidia (32.4%) accounted for the largest proportions of gut microbiota. The proportion of Clostridia was numerically reduced in C. difficile-inoculated versus normal mice. Administration of vancomycin to C. difficile-inoculated mice reduced the proportions of Bacteroidia and Clostridia, and increased that of Proteobacteria. Administration of fidaxomicin to C. difficile-inoculated mice reduced the proportion of Clostridia to a lesser extent, but increased that of Bacteroidia. Microbiota diversity was lower in C. difficile-inoculated versus normal mice (164.5 versus 349.1 operational taxonomic units (OTUs), respectively); treatment of C. difficile-inoculated mice with 7 days' vancomycin reduced diversity to a greater extent than did 7 days' fidaxomicin treatment (26.2 versus 134.2 OTUs, respectively).

CONCLUSIONS

Both C. difficile inoculation and treatment with vancomycin or fidaxomicin reduced microbiota diversity; however, dysbiosis associated with fidaxomicin was milder than with vancomycin.

Modified Mouse Model of Clostridioides difficile Infection as a Platform for Probiotic Efficacy Studies

Probiotics may represent a promising approach for reducing Clostridioides (Clostridium) difficile infections (CDIs). A clinical trial conducted by our group demonstrated that CDI patients undergoing adjunctive treatment with Lactobacillus and Bifidobacterium probiotics had a reduction in diarrheal duration and compositional changes in their stool microbiomes. Here, we modified a CDI mouse model to represent clinical outcomes observed in patients and employed this model to identify evidence for the prevention of primary CDI and relapse with the same probiotic. Mice (n = 80) were administered 0.25 mg/ml cefoperazone over 5 days and subsequently challenged with 10² C. difficile VPI 10463 spores. A subset of mice (n = 40) were administered 10⁸ CFU of probiotics daily alongside cefoperazone pretreatment and until experimental endpoints were reached. Clinical scoring was performed daily on mice and used to evaluate CDI onset and severity. Moderate CDI in mice was defined by survival beyond day 3 postinfection, while mice with severe CDI were those who succumbed to infection prior to day 3 postinfection. Sequencing and analysis of 16S rRNA from stool content were performed to determine compositional alterations to the microbiota. Using total clinical scores, we identified an association between probiotic treatment and delayed onset of primary CDI and relapse by approximately 12 to 24 h (P < 0.001). The stool microbiome of mice with moderate CDI receiving probiotic treatment was significantly enriched with Lachnospiraceae during primary CDI (P < 0.05). The outcomes observed present an opportunity to use this modified CDI mouse model to examine the efficacy of nonantibiotic options for CDI management.

Vancomycin-Loaded Nanoparticles Enhance Sporicidal and Antibacterial Efficacy for Clostridium difficile Infection

Current antibiotic treatments fail to eliminate the Clostridium difficile (C. difficile) spores and induce dysbiosis and intestinal inflammation via off-target effect, which causes refractory C. difficile infection raise an unmet need for a spore-specific antimicrobial treatment. We developed a sporicidal and antimicrobial vancomycin-loaded spore-targeting iron oxide nanoparticle (van-IONP) that selectively binds to C. difficile spores. Cryo-electron microscopy showed that vancomycin-loaded nanoparticles can target and completely cover spore surfaces. They not only successfully delayed the germination of the spores but also inhibited ∼50% of vegetative cell outgrowth after 48 h of incubation. The van-IONPs also inhibited the interaction of spores with HT-29 intestinal mucosal cells in vitro. In a murine model of C. difficile infection, the van-IONP significantly protected the mice from infected by C. difficile infection, reducing intestinal inflammation, and facilitated superior mucosal viability compared with equal doses of free vancomycin. This dual-function targeted delivery therapy showed advantages over traditional therapeutics in treating C. difficile infection.

Recurrent Clostridium difficile Infection: Risk Factors, Treatment, and Prevention

The most common cause of antibiotic-associated diarrhea is Clostridium difficile infection (CDI). Recurrent C. difficile infection (rCDI) often occurs after successful treatment of CDI. Due to the increased incidence and the difficulty in treating rCDI, it is becoming an important clinical issue. Identifying risk factors is helpful for early detection, treatment, and prevention of rCDI. Advanced age, use of antibiotics, gastric acid suppression, and infection with a hypervirulent strain are currently regarded as the major risk factors for rCDI. Several treatment modalities, including vancomycin, fidaxomicin, and fecal microbiota transplant (FMT), are suggested for rCDI treatment. However, there is currently no definitive treatment method with sufficient evidence for rCDI. Recent studies have focused on FMT and have shown positive results for rCDI. Prevention of rCDI by measures such as hand washing and isolation of patients is very important. However, these preventive measures are often overlooked in clinical practice. Here, we review the risk factors, treatment, and prevention of rCDI.

Clostridium sordellii outer spore proteins maintain spore structural integrity and promote bacterial clearance from the gastrointestinal tract

Bacterial spores play an important role in disease initiation, transmission and persistence. In some species, the exosporium forms the outermost structure of the spore and provides the first point of contact between the spore and the environment. The exosporium may also be involved in spore adherence, protection and germination. Clostridium sordellii is a highly lethal, spore forming pathogen that causes soft-tissue infections, enteritis and toxic-shock syndrome. Despite the importance of C. sordellii spores in disease, spore proteins from this bacterium have not been defined or interrogated functionally. In this study, we identified the C. sordellii outer spore proteome and two of the identified proteins, CsA and CsB, were characterised using a genetic and phenotypic approach. Both proteins were essential for the correct formation and positioning of the C. sordellii spore coat and exosporium. The absence of CsA reduced sporulation levels and increased spore sensitivity to heat, sodium hydroxide and hydrochloric acid. By comparison, CsB was required for normal levels of spore adherence to cervical, but not vaginal, cells, with csB mutant spores having increased adherence properties. The establishment of a mouse infection model of the gastrointestinal tract for C. sordellii allowed the role of CsA and CsB to be interrogated in an infected host. Following the oral administration of spores to mice, the wild-type strain efficiently colonized the gastrointestinal tract, with the peak of bacterial numbers occurring at one day post-infection. Colonization was reduced by two logs at four days post-infection. By comparison, mice infected with the csB mutant did not show a reduction in bacterial numbers. We conclude that C. sordellii outer spore proteins are important for the structural and functional integrity of spores. Furthermore, outer spore proteins are required for wild-type levels of colonization during infection, possibly as a result of the role that the proteins play in spore structure and morphology.

In vitro activity of DS-2969b and comparator antimicrobial agents against Clostridioides (Clostridium) difficile, methicillin-resistant Staphylococcus aureus, and other anaerobic bacteria

The in vitro activity of DS-2969b, a novel GyrB inhibitor, and six comparator agents was studied against 101 recent North American Clostridioides difficile isolates, 46 other intestinal anaerobes and 51 strains of methicillin-resistant Staphylococcus aureus. The MIC ranges (MIC_90s) of DS-2969b against C. difficile and S. aureus were 0.03-0.125 (0.125) μg/ml and 0.125-1 (0.5) μg/ml, respectively. DS-2969b showed the greatest activity of the agents tested. There was no difference in MICs of DS-2969b among different ribotypes.

Clostridium difficile Infection at Diagnosis and during the Disease Course of Pediatric Inflammatory Bowel Disease

PURPOSE

Clostridium difficile colonization and infection are commonly associated with poor outcomes in patients with pediatric inflammatory bowel disease (PIBD). We aimed to investigate the prevalence of C. difficile colonization and infection at the time of diagnosis and to evaluate risk factors associated with the development of C. difficile infection during the course of PIBD treatment.

METHODS

We retrospectively enrolled a total of 59 children who were newly diagnosed with PIBD at the tertiary medical center. All patients underwent C. difficile toxin assays and cultures initially and at every follow-up during the disease course. Kaplan-Meier survival analysis and Cox regression test were used for statistical analysis.

RESULTS

Initial cultures for C. difficile were positive in 13 (22.0%) of 59 PIBD patients, whereas initial toxin assays were positive in 3 patients (5.1%). During treatment, C. difficile cultures converted to positive in 28 (47.5%) in addition to 13 patients who were initially culture-positive, and C. difficile toxins converted to positive in 13 (22.0%) in addition to 3 originally toxin-positive patients. Antibiotic usage alone was significantly associated with the development of C. difficile colonization (p=0.011), and the length of hospitalization was associated with the development of C. difficile infection (p=0.032).

CONCLUSION

C. difficile colonization and infection occur frequently during the disease course of PIBD. Antibiotic usage and longer hospital stay were significant risks factors for the conversion of C. difficile status in PIBD patients undergoing treatment.