Risk Factors and Outcomes for Bloodstream Infections Secondary to Clostridium difficile Infection

Recurrent Clostridioides difficile infections in solid organ transplant recipients: The international CALIPSO study

OBJECTIVE

To evaluate the risk of recurrent Clostridioides difficile infection (CDI) in solid-organ transplant (SOT) recipients.

METHODS

Retrospective multicenter study including SOT recipients with a first CDI episode in the year after transplantation (Jan 2017-June 2020). The primary outcome measure was recurrence, defined as a new CDI ≤56 days from the first episode. A competing risk analysis was performed using the sub-distribution hazard model multivariable analysis.

RESULTS

191 SOT recipients were included: 101 (52.9%) were kidney, 66 (34.6%) liver, 11 (5.8%) lung, 8 (4.2%) simultaneous pancreas-kidney, 4 (2.1%) heart and 1 (0.5%) pancreas alone recipients. Treatment for the first CDI were: vancomycin (n = 114,59.7%), vancomycin+metronidazole (n = 39,20.4%), metronidazole (n = 26,13.6%), fidaxomicin (n = 9,4.7%), 3 patients did not receive any therapy. After the first CDI, 17/191 (8.9%) patients died within 56-day mortality without having a recurrence, while 23/191 (12%) patients had a recurrence. Among patients with recurrent CDI, 56-day mortality rate was 30.4% (7/23 patients). On multivariable analysis, severe CDI (sHR4.01, 95% CI 1.77-9.08, p < .001) and metronidazole monotherapy (sHR 3.65, 95% CI 1.64-8.14, p = .001) were factors independently associated with recurrence.

CONCLUSIONS

Metronidazole monotherapy is associated with increased risk of recurrent CDI in SOT recipients. Therapeutic strategies aimed to reduce the risk of recurrence should be implemented in this setting.

Decreased Phagocytosis and Intracellular Killing of Bacteria in Leukocytes of Geriatric Patients with Clostridioides difficile Infections

INTRODUCTION

Patients suffering from a Clostridioides difficile infection have a higher overall mortality than patients with similar comorbidities.

METHODS

Whole blood samples of 15 patients with C. difficile enteritis and 15 control patients matched for age and sex were used to analyze the capacity of blood phagocytes to internalize and kill encapsulated Escherichia (E.) coli. The median age of C. difficile patients and control patients was 81 and 82 years, respectively. Blood samples were co-incubated with E. coli for 15 or 30 min. After 15 min of co-incubation, extracellular bacteria were killed by gentamicin for 15-45 min. Then eukaryotic cells were lysed with distilled water, and the number of intracellular bacteria per ml whole blood was determined by quantitative plating on agar plates. Both groups were compared by Mann-Whitney U test.

RESULTS

After 15 or 30 min of co-incubation, blood phagocytes from patients with C. difficile enteritis showed a reduced density of phagocytosed or adherent bacteria in comparison to blood phagocytes from control patients (15 min: p = 0.046, 30 min: p = 0.005). The density of intracellular bacteria decreased less rapidly over time in the blood from C. difficile patients (median Δlog CFU/mL × h [25th/75th percentile] -0.893 [-1.893/-0.554] vs. -1.483 [-2.509/-1.028]; p = 0.02). In line with these results, the percentage of intracellularly killed bacteria was decreased in phagocytes from C. difficile-infected patients compared to controls (median intracellular killing rate 64.3% for blood phagocytes from C. difficile patients vs. 81.9% for blood phagocytes from control patients within 30 min of co-incubation, p = 0.048).

CONCLUSION

Blood phagocytes from patients with C. difficile enteritis exhibited a reduced capacity to phagocytose and kill bacteria in comparison to blood phagocytes from age- and sex-matched control patients. Patients with C. difficile infection may have a higher disposition to develop infectious diseases than age- and sex-matched control patients.

Clostridioides difficile infection: history, epidemiology, risk factors, prevention, clinical manifestations, treatment, and future options

SUMMARYClostridioides difficile infection (CDI) is one of the major issues in nosocomial infections. This bacterium is constantly evolving and poses complex challenges for clinicians, often encountered in real-life scenarios. In the face of CDI, we are increasingly equipped with new therapeutic strategies, such as monoclonal antibodies and live biotherapeutic products, which need to be thoroughly understood to fully harness their benefits. Moreover, interesting options are currently under study for the future, including bacteriophages, vaccines, and antibiotic inhibitors. Surveillance and prevention strategies continue to play a pivotal role in limiting the spread of the infection. In this review, we aim to provide the reader with a comprehensive overview of epidemiological aspects, predisposing factors, clinical manifestations, diagnostic tools, and current and future prophylactic and therapeutic options for C. difficile infection.

Fecal Microbiota Transplantation as Emerging Treatment in European Countries 2.0

Clostridioides difficile infection (CDI) is one of the most common healthcare-associated infections and one of the leading causes of morbidity and mortality in hospitalized patients in the world. Although several antibiotics effectively treat CDI, some individuals may not respond to these drugs and may be cured by transplanting stool from healthy donors. FMT has demonstrated extraordinary cure rates for the cure of CDI recurrences.Moreover, FMT has also been investigated in other disorders associated with the alteration of gut microbiota, such as inflammatory bowel disease (IBD), where the alterations of the gut microbiota ecology have been theorized to play a causative role. Although FMT is currently not recommended to cure IBD patients in clinical practice, several studies have been recently carried out with the ultimate goal to search new therapeutic options to patients.This review summarizes data on the use of FMT for the treatment of both CDI and IBD, with a special attention to highlight studies conducted in European countries.

Increased Incidence and Risk of Septicemia and Urinary Tract Infection After Clostridioides difficile Infection

Background

Although increased occurrence of septicemia in persons with Clostridioides difficile infection (CDI) has been reported, incidence rates and risk of septicemia and urinary tract infection (UTI) after CDI are unclear.

Methods

The first episode of CDI was identified using 2011-2017 MarketScan and CMS Medicare data and CDI cases categorized by standard surveillance definitions. Uninfected persons were frequency matched 4:1 to cases by the CDI case surveillance definition. Multivariable Cox proportional hazards models were used to identify risk factors for septicemia and UTI within 90 days of CDI onset, accounting for the competing risk of death in the Medicare population.

Results

The incidence of septicemia was highest after hospital-onset CDI in the Medicare, younger commercial, and younger Medicaid populations (25.5%, 15.7%, and 19.5%, respectively) and lowest in those with community-associated CDI (3.8%, 4.3%, and 8.3%, respectively). In contrast, the incidence of UTI was highest in those with other healthcare facility onset CDI in all 3 populations (32.1%, 24.2%, and 18.1%, respectively). Hospital-onset CDI was associated with highest risk of septicemia compared with uninfected controls in all 3 populations. In the younger populations, risk of septicemia was more uniform across the CDI surveillance definitions. The risk of UTI was significantly higher in all CDI surveillance categories compared to uninfected controls, and among CDI cases it was lowest in those with community-associated CDI.

Conclusions

The incidence of septicemia is high after CDI, particularly after hospital-onset infection. Additional preventive measures are needed to reduce infectious complications of CDI.

The burden of CDI in the United States: a multifactorial challenge

Clostridioides difficile infection (CDI) affects approximately 500,000 patients annually in the United States, of these around 30,000 will die. CDI carries significant burdens including clinical, social and economic. While healthcare-associated CDI has declined in recent years, community-associated CDI is on the rise. Many patients are also impacted by recurrent C. difficile infections (rCDI); up to 35% of index CDI will recur and of these up to 60% will further recur with multiple recurrences observed. The range of outcomes adversely affected by rCDI is significant and current standard of care does not alter these recurrence rates due to the damaged gut microbiome and subsequent dysbiosis. The clinical landscape of CDI is changing, we discuss the impact of CDI, rCDI, and the wide range of financial, social, and clinical outcomes by which treatments should be evaluated.

Gut microbiota and microbiota-based therapies for Clostridioides difficile infection

Clostridioides difficile infection poses significant clinical challenges due to its recurrent nature. Current antibiotic management does not address the underlying issue, that of a disturbed gastrointestinal microbiome, called dysbiosis. This provides a supportive environment for the germination of C. difficile spores which lead to infection and toxin production as well as an array of other health conditions. The use of microbiome restoration therapies such as live biotherapeutics can reverse dysbiosis and lead to good clinical outcomes. Several such therapies are under clinical investigation.

Long-term antibiotic exposure promotes mortality after systemic fungal infection by driving lymphocyte dysfunction and systemic escape of commensal bacteria

Antibiotics are a modifiable iatrogenic risk factor for the most common human nosocomial fungal infection, invasive candidiasis, yet the underlying mechanisms remain elusive. We found that antibiotics enhanced the susceptibility to murine invasive candidiasis due to impaired lymphocyte-dependent IL-17A- and GM-CSF-mediated antifungal immunity within the gut. This led to non-inflammatory bacterial escape and systemic bacterial co-infection, which could be ameliorated by IL-17A or GM-CSF immunotherapy. Vancomycin alone similarly enhanced the susceptibility to invasive fungal infection and systemic bacterial co-infection. Mechanistically, vancomycin reduced the frequency of gut Th17 cells associated with impaired proliferation and RORγt expression. Vancomycin's effects on Th17 cells were indirect, manifesting only in vivo in the presence of dysbiosis. In humans, antibiotics were associated with an increased risk of invasive candidiasis and death after invasive candidiasis. Our work highlights the importance of antibiotic stewardship in protecting vulnerable patients from life-threatening infections and provides mechanistic insights into a controllable iatrogenic risk factor for invasive candidiasis.

Clinical Impact of COVID-19 on Multi-Drug-Resistant Gram-Negative Bacilli Bloodstream Infections in an Intensive Care Unit Setting: Two Pandemics Compared

Two mutually related pandemics are ongoing worldwide: the COVID-19 and antimicrobial resistance pandemics. This study aims to evaluate the impact of COVID-19 on multi-drug-resistant Gram-negative bacteria (MDR-GN) bloodstream infections (BSIs) in a single intensive care unit (ICU). We conducted a retrospective study including patients admitted to the ICU, reorganized for COVID-19 patients' healthcare, with at least one confirmed MDR-GN BSI during 2019-2020. We compared clinical and microbiological features, incidence density, antibiotic therapy and mortality rate in pre- and during-COVID-19 pandemic periods. We estimated the impact of COVID-19 on mortality by means of univariate Cox regression analyses. A total of 46 patients were included in the study (28 non-COVID-19/18 COVID-19). Overall, 63 BSI episodes occurred (44/19), and non-COVID-19 patients had a higher incidence of MDR-GN BSIs and were more likely to present K. pneumoniae BSIs, while the COVID-19 group showed more A. baumannii BSIs with higher per pathogen incidence. COVID-19 patients presented more critical conditions at the BSI onset, a shorter hospitalization time from BSI to death and higher 30-day mortality rate from BSI onset. COVID-19 and septic shock were associated with 30-day mortality from MDR-GN BSIs, while early active therapy was a protective factor. In conclusion, COVID-19 showed a negative impact on patients with MDR-GN BSIs admitted to the ICU.

Concurrent and Subsequent Co-Infections of Clostridioides difficile Colitis in the Era of Gut Microbiota and Expanding Treatment Options

We narratively reviewed the physiopathology, epidemiology, and management of co-infections in Clostridioides difficile colitis (CDI) by searching the following keywords in Embase, MedLine, and PubMed: “Clostridium/Clostridioides difficile”, “co-infection”, “blood-stream infection” (BSI), “fungemia”, “Candida”, “Cytomegalovirus”, “probiotics”, “microbial translocation” (MT). Bacterial BSIs (mainly by Enterobacteriaceae and Enterococcus) and fungemia (mainly by Candida albicans) may occur in up to 20% and 9% of CDI, increasing mortality and length of hospitalization. Up to 68% of the isolates are multi-drug-resistant bacteria. A pivotal role is played by gut dysbiosis, intestinal barrier leakage, and MT. Specific risk factors are represented by CDI-inducing broad-spectrum antibiotics, oral vancomycin use, and CDI severity. Probiotics administration (mainly Saccharomyces and Lactobacillus) during moderate/severe CDI may favor probiotics superinfection. Other co-infections (such as Cytomegalovirus or protozoa) can complicate limited and specific cases. There is mounting evidence that fidaxomicin, bezlotoxumab, and fecal microbiota transplantation can significantly reduce the rate of co-infections compared to historical therapies by interrupting the vicious circle between CDI, treatments, and MT. Bacterial BSIs and candidemia represent the most common co-infections in CDI. Physicians should be aware of this complication to promptly diagnose and treat it and enforce preventive strategies that include a more comprehensive consideration of newer treatment options.

Mechanisms of peripheral levodopa resistance in Parkinson's disease

Parkinson’s disease (PD) is an increasingly common neurodegenerative condition. The disease has a significant negative impact on quality of life, but a personalized management approach can help reduce disability. Pharmacotherapy with levodopa remains the cornerstone of treatment, and a gratifying and sustained response to this treatment is a supportive criterion that argues in favor of an underlying diagnosis of PD. Yet, in daily practice, it is not uncommon to encounter patients who appear to have true PD, but who nevertheless seem to lose the responsiveness to levodopa (secondary non-responders). Some patients may even fail to respond altogether (primary non-responders). Here, we address how two mechanisms of “peripheral resistance” may underlie this failing response to levodopa in persons with PD. The first explanation relates to impaired bowel motility leading to secondary bacterial overgrowth, and more specifically, to the excessive bacterial production of the enzyme tyrosine decarboxylase (TDC). This enzyme may convert levodopa to dopamine in the gut, thereby hampering entry into the circulation and, subsequently, into the brain. The second explanation relates to the systemic induction of the enzyme aromatic l-amino acid decarboxylase (AADC), leading to premature conversion of levodopa into dopamine, again limiting the bioavailability within the brain. We discuss these two mechanisms and focus on the clinical implications, potential treatments and directions for future research.

American Society for Transplantation and Cellular Therapy Series: #5-Management of Clostridioides difficile Infection in Hematopoietic Cell Transplant Recipients

The Practice Guidelines Committee of the American Society for Transplantation and Cellular Therapy partnered with its Transplant Infectious Disease Special Interest Group to update its 2009 compendium-style infectious disease guidelines for hematopoietic cell transplantation (HCT). A completely new approach was taken with the goal of better serving clinical providers by publishing each standalone topic in the infectious disease series as a concise format of frequently asked questions (FAQ), tables, and figures. Adult and pediatric infectious disease and HCT content experts developed and then answered FAQs and finalized topics with harmonized recommendations that were made by assigning an A through E strength of recommendation paired with a level of supporting evidence graded I through III. This fifth guideline in the series focuses on Clostridioides difficile infection with FAQs that address the prevalence, incidence, clinical features, colonization versus infection, clinical complications, diagnostic considerations, pharmacological therapies for episodic or recurrent infection, and the roles of prophylactic antibiotics, probiotics, and fecal microbiota transplantation.

An Atypical Case of Monomicrobial Clostridioides difficile Septicemia With No Gastrointestinal Manifestations

An uncommon case of monomicrobial Clostridioides difficile septicemia in a 63-year-old man was reported in Zhejiang, China. Once diagnosed, vancomycin treatment cleared the infections. The patient had no remarkable medical history, and the inspection showed no overt gastrointestinal symptoms, though C. difficile was detected in his stool samples. However, we later defined that the C. difficile strain isolated from the blood sample was different from the one isolated from his stool using the whole genome sequencing analysis. By retrospective analysis of his medical record, we noticed that the man had a recent tooth extraction thus the bacterium may have invaded through the root canal. Therefore, we suggest that oral C. difficile colonization may be a potential risk factor for severe C. difficile septicemia, which could be clinically alarming.

Oral Vancomycin Prophylaxis for Primary and Secondary Prevention of Clostridioides difficile Infection in Patients Treated with Systemic Antibiotic Therapy: A Systematic Review, Meta-Analysis and Trial Sequential Analysis

Background: Clostridioides difficile infection (CDI) is associated with substantial morbidity and mortality as well as high propensity of recurrence. Systemic antibiotic therapy (SAT) represents the top inciting factor of CDI, both primary and recurrent (rCDI). Among the many strategies aimed to prevent CDI in high-risk subjects undergoing SAT, oral vancomycin prophylaxis (OVP) appears promising under a cost-effectiveness perspective. Methods: A systematic review with meta-analysis and trial sequential analysis (TSA) of studies assessing the efficacy and the safety of OVP to prevent primary CDI and rCDI in persons undergoing SAT was carried out. PubMed and EMBASE were searched until 30 September 2021. The protocol was pre-registered on PROSPERO (CRD42019145543). Results: Eleven studies met the inclusion criteria, only one being a randomized controlled trial (RCT). Overall, 929 subjects received OVP and 2011 represented the comparator group (no active prophylaxis). OVP exerted a strong protective effect for CDI occurrence: odds ratio 0.14, 95% confidence interval 0.04–0.38. Moderate heterogeneity was observed: I² 54%. This effect was confirmed throughout several subgroup analyses, including prevention of primary CDI versus rCDI. TSA results pointed at the conclusive nature of the evidence. Results were robust to a variety of sensitivity and quantitative bias analyses, although the underlying evidence was deemed as low quality. No differences between the two groups were highlighted regarding the onset of vancomycin-resistant Enterococcus infections. Conclusions: OVP appears to be an efficacious option for prevention of CDI in high-risk subjects undergoing SAT. Nevertheless, additional data from RCTs are needed to establish OVP as good clinical practice and define optimal dosage and duration.

Clinical burden of recurrent Clostridioides difficile infection in the medicare population: A real-world claims analysis

OBJECTIVE

To describe 12-month outcomes for beneficiaries in the 100% Medicare Fee-for-Service (FFS) population with primary and recurrent Clostridioides difficile infection (CDI).

DESIGN

A retrospective, descriptive, cohort study of CDI claims from the 100% Medicare FFS population, with a first CDI diagnosis between January 1, 2010, and December 31, 2016.

SETTING

Any US-based provider that submitted inpatient or outpatient CDI diagnosis claims to Medicare FFS.

PATIENTS

The study included patients aged ≥65 years with continuous enrollment in Medicare Parts A, B, and D during 12 months before and 12 months after the index period.

METHODS

The number of CDI and recurrent (rCDI) episodes, healthcare resource utilization, treatments, complications, and procedures were calculated for pre-index and follow-up periods. The data were stratified by number of rCDI episodes (ie, no rCDI, 1 rCDI, 2 rCDI, and ≥3 rCDI).

RESULTS

Of 268,762 patients with an index CDI, 34.7% had at least 1 recurrence. Of those who had 1 recurrence, 59.1% had a second recurrence and of those who had 2 recurrences, 58.4% had ≥3 recurrences. Incident psychiatric conditions occurred in 11.3%-18.2% of each rCDI cohort; 6.0% of patients with rCDI underwent subtotal colectomy, and 1.1% of patients underwent diverting loop ileostomy. After each CDI episode, ∼1 in 5 patients had a documented sepsis event. Over the 12-month follow-up, 30% of patients experienced sepsis, and sepsis occurred in 27.0% of the cohort with no rCDI, compared to 35.5% of patients in the rCDI cohorts.

CONCLUSIONS

Elderly patients with CDI and rCDI experienced a significant clinical burden and complications.

Mortality, healthcare resource utilization, and cost among Medicare beneficiaries with Clostridioides difficile infection with and without sepsis

Objective

To describe mortality, healthcare resource utilization (HRU), and costs among Medicare beneficiaries with primary Clostridioides difficile infection (pCDI) or recurrent CDI (rCDI), with and without sepsis.

Methods

We conducted a retrospective observational study of 100% Medicare Fee-for-Service claims from adults aged ⩾ 65 years with ⩾1 CDI episode between 1 January 2009 and 31 December 2017. Patients were continuously enrolled in Medicare Parts A/B/D 12 months before and up to 12 months after pCDI. ICD-9/10 codes defined CDI using ⩾1 inpatient claim, or ⩾1 outpatient claim plus ⩾1 claim for CDI treatment. The pCDI episode ended after 14 days without a CDI claim. rCDI episodes started within 8 weeks from the end of a previous CDI episode. ICD-9/10 codes identified all-cause sepsis over 12 month follow-up.

Results

Of 497,489 CDI patients, 41.0% (N = 203,888) had sepsis; 57.7% with sepsis died versus 32.4% without sepsis. Among patients with pCDI only (N = 345,893) or ⩾1 rCDI (N = 151,596), 39.2% and 45.1% suffered sepsis, respectively. All-cause hospitalizations were frequent for all cohorts (range: 81-99%). Among patients who died, those with sepsis versus without had more-frequent intensive care unit (ICU) use (pCDI: 29% versus 15%; rCDI: 65% versus 34%), longer hospital stays (pCDI: 12 versus 10 days; rCDI: 12 versus 9 days), and higher per-patient-per-month costs (pCDI: $34,841 versus $22,753; rCDI: $42,269 versus $25,047). In both cohorts, sepsis patients who survived had higher total costs and all-cause HRU than those without sepsis. All p < 0.001 above.

Conclusions

Sepsis was common among Medicare beneficiaries with CDI. CDI patients with sepsis, especially after an rCDI, experienced higher mortality, HRU, and costs compared with those without sepsis.

Donor program for fecal microbiota transplantation: A 3-year experience of a large-volume Italian stool bank

BACKGROUND

Due to the increasing rise of C. difficile infection, stool banks and donor programs have been launched to grant access to fecal microbiota transplantation (FMT). Our aim is to describe characteristics and outcomes of the donor program at our stool bank.

METHODS

Donor candidates underwent a four-step selection process, including a clinical interview, blood and stool testing, a further questionnaire and a direct stool testing the day of each donation. From March 2020, specific changes to this process were introduced to avoid the potential transmission of COVID-19. We evaluated the rate of excluded candidates at each step of the screening, as well as the number of total fecal aliquots provided by qualified donors.

RESULTS

Overall, 114 donor candidates were evaluated. Seventy-five candidates declined to join the program for logistic or personal issues, three were excluded after the questionnaire and seven for positive stool exams. Finally, 29 (25%) subjects qualified as stool donors, and provided 70 stool samples. Fifteen samples were excluded after direct molecular stool testing. A total of 127 aliquots was finally obtained.

CONCLUSIONS

Donor recruitment for FMT is a challenging process, and only a small rate of candidates are eligible as donors.

Detection of Pathogenic Bacteria From Septic Patients Using 16S Ribosomal RNA Gene-Targeted Metagenomic Sequencing

BACKGROUND

Conventional blood cultures were compared to plasma cell-free DNA-based 16S ribosomal RNA (rRNA) gene polymerase chain reaction (PCR)/next-generation sequencing (NGS) for detection and identification of potential pathogens in patients with sepsis.

METHODS

Plasma was prospectively collected from 60 adult patients with sepsis presenting to the Mayo Clinic (Minnesota) Emergency Department from March through August 2019. Results of routine clinical blood cultures were compared to those of 16S rRNA gene NGS.

RESULTS

Nineteen (32%) subjects had positive blood cultures, of which 13 yielded gram-negative bacilli, 5 gram-positive cocci, and 1 both gram-negative bacilli and gram-positive cocci. 16S rRNA gene NGS findings were concordant in 11. For the remaining 8, 16S rRNA gene NGS results yielded discordant detections (n = 5) or were negative (n = 3). Interestingly, Clostridium species were additionally detected by 16S rRNA gene NGS in 3 of the 6 subjects with gastrointestinal sources of gram-negative bacteremia and none of the 3 subjects with urinary sources of gram-negative bacteremia. In the 41 remaining subjects, 16S rRNA gene NGS detected at least 1 potentially pathogenic organism in 17. In 15, the detected microorganism clinically correlated with the patient's syndrome. In 17 subjects with a clinically defined infectious syndrome, neither test was positive; in the remaining 7 subjects, a noninfectious cause of clinical presentation was identified.

CONCLUSIONS

16S rRNA gene NGS may be useful for detecting bacteria in plasma of septic patients. In some cases of gram-negative sepsis, it may be possible to pinpoint a gastrointestinal or urinary source of sepsis based on the profile of bacteria detected in plasma.

DNA Repair in Staphylococcus aureus

Staphylococcus aureus is a common cause of both superficial and invasive infections of humans and animals. Despite a potent host response and apparently appropriate antibiotic therapy, staphylococcal infections frequently become chronic or recurrent, demonstrating a remarkable ability of S. aureus to withstand the hostile host environment. There is growing evidence that staphylococcal DNA repair makes important contributions to the survival of the pathogen in host tissues, as well as promoting the emergence of mutants that resist host defenses and antibiotics. While much of what we know about DNA repair in S. aureus is inferred from studies with model organisms, the roles of specific repair mechanisms in infection are becoming clear and differences with Bacillus subtilis and Escherichia coli have been identified. Furthermore, there is growing interest in staphylococcal DNA repair as a target for novel therapeutics that sensitize the pathogen to host defenses and antibiotics. In this review, we discuss what is known about staphylococcal DNA repair and its role in infection, examine how repair in S. aureus is similar to, or differs from, repair in well-characterized model organisms, and assess the potential of staphylococcal DNA repair as a novel therapeutic target.

How to: prophylactic interventions for prevention of Clostridioides difficile infection

BACKGROUND

Clostridioides difficile infection (CDI) remains the leading cause of healthcare-associated diarrhoea, despite existing guidelines for infection control measures and antimicrobial stewardship. The high associated health and economic burden of CDI calls for novel strategies to prevent the development and spread of CDI in susceptible patients.

OBJECTIVES

We aim to review CDI prophylactic treatment strategies and their implementation in clinical practice.

SOURCES

We searched PubMed, Embase, Emcare, Web of Science, and the COCHRANE Library databases to identify prophylactic interventions aimed at prevention of CDI. The search was restricted to articles published in English since 2012.

CONTENT

A toxin-based vaccine candidate is currently being investigated in a phase III clinical trial. However, a recent attempt to develop a toxin-based vaccine has failed. Conventional probiotics have not yet proved to be an effective strategy for prevention of CDI. New promising microbiota-based interventions that bind and inactivate concomitantly administered antibiotics, such as ribaxamase and DAV-132, have been developed. Prophylaxis of CDI with C. difficile antibiotics should not be performed routinely and should be considered only for secondary prophylaxis in very selected patients who are at the highest imminent risk for recurrent CDI (R-CDI) after a thorough evaluation. Faecal microbiota transplantation (FMT) has proved to be a very effective treatment for patients with multiple recurrences. Bezlotoxumab provides protection against R-CDI, mainly in patients with primary episodes and a high risk of relapse.

IMPLICATIONS

There are no proven effective, evidenced-based prophylaxis options for primary CDI. As for secondary prevention, FMT is considered the option of choice in patients with multiple recurrences. Bezlotoxumab can be added to standard treatment for patients at high risk for R-CDI. The most promising strategies are those aimed at reducing changes in intestinal microbiota and development of a new effective non-toxin-based vaccine.

Microbiota-based Therapies Clostridioides difficile infection that is refractory to antibiotic therapy

Clostridioides difficile infection (CDI) has had a devastating impact worldwide with significant rates of mortality, especially among the elderly. Despite effective antibiotics, the incidence of recurrent CDI (rCDI) is increasing and more difficult to treat with antibiotics alone. Fecal Microbiota Transplantation (FMT) has emerged as a consistently effective treatment for rCDI. Mechanisms for FMT are not entirely understood, but remain an area of active investigation. There have been recent safety reports with the use of FMT regarding transmission of pathogens in a few patients that have led to serious illness. With appropriate screening, FMT can be safely administered and continue to have a significant impact on eradication of rCDI and improve the lives of patients suffering from this disease. In this review, we summarize current treatments for CDI with a focus on microbiota-based therapies used for antibiotic refractory disease.

Comparison of Clostridioides difficile strains from animals and humans: First results after introduction of C. difficile molecular typing and characterization at the Istituto Zooprofilattico Sperimentale of Piemonte, Liguria e Valle d'Aosta, Italy

PCR ribotypes (RTs027 and 078) are known causes of Clostridioides difficile infection (CDI) in humans. Molecular typing and characterization of 39 C. difficile strains isolated from samples from humas and animals in 2016-2018 indicated an overlap of RTs between community-acquired patients (CA-CDI) and domestic animals from the same geographical area; 14 RTs were identified: 12 RTs were positive for toxins A/B; RT078, RT080 and RT126 were also positive for binary toxin (CDT). Most of the RTs from the animals (RTs020, 078, 106, 126) were also detected in the samples from humans. Strains grouped into three clusters: cluster I included prevalently human strains, mainly RT 018; clusters II and III included strains from humans and animals, mainly RT078 and RT020. The CA-CDI strains suggested animals as a reservoir of C. difficile isolated together with other microorganisms from animals, highlighting the association of enteric pathogens as a cause of infection and death.

Clinical complications in patients with primary and recurrent Clostridioides difficile infection: A real-world data analysis

Objective:

Clostridioides difficile infection and recurrent C. difficile infection result in substantial economic burden and healthcare resource use. Sepsis and bowel surgery are known to be serious complications of C. difficile infection. This study evaluated clinical complications in patients with C. difficile infection and recurrent C. difficile infection during a 12-month period following the primary C. difficile infection.

Methods:

A retrospective analysis of commercial claims data from the IQVIA PharMetrics Plus™ database was conducted for patients aged 18–64 years with an index C. difficile infection episode requiring inpatient stay or an outpatient visit for C. difficile infection followed by a C. difficile infection treatment. Each C. difficile infection episode ended after a 14-day C. difficile infection-claim-free period was observed. Recurrent C. difficile infection was defined as a further C. difficile infection episode within an 8-week window following the claim-free period. Clinical complications were documented over 12 months of follow-up and stratified by the number of recurrent C. difficile infection episodes (0 rCDI, 1 rCDI, 2 rCDI, and 3+ rCDI).

Results:

In total, 46,571 patients with index C. difficile infection episode were included. During the 6-month pre-index, the mean (standard deviation) baseline Charlson comorbidity index score, by increasing the recurrent C. difficile infection group, was 1.2 (1.9), 1.5 (2.2), 1.8 (2.3), and 2.3 (2.5). During the 12-month follow-up, sepsis occurred in 16.5%, 27.3%, 33.1%, and 43.3% of patients, and subtotal colectomy or diverting loop ileostomy was performed in 4.6%, 7.3%, 8.9%, and 10.5% of patients, respectively, by increasing the recurrent C. difficile infection group.

Conclusions:

Reduction in recurrent C. difficile infection is an important step to reduce the burden of serious clinical complications, and new treatments are needed to reduce C. difficile infection recurrence.

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.

Predictive factors for sepsis by carbapenem resistant Gram-negative bacilli in adult critical patients in Rio de Janeiro: a case-case-control design in a prospective cohort study

Background

Studies have investigated risk factors for infections by specific species of carbapenem-resistant Gram-negative bacilli (CR-GNB), but few considered the group of GNB species and most of them were performed in the setting of bacteremia or hospital infection. This study was implemented to identify risk factors for sepsis by CR- and carbapenem-susceptible (CS) GNB in intensive care unit (ICU) patients to improve management strategies for CR-GNB sepsis.

Methods

We developed a case-case-control study from a prospective cohort of patients with systemic inflammatory response syndrome (SIRS), sepsis-2 or sepsis-3 criteria in which blood and other sample cultures were collected and antimicrobial therapy was instituted, in an adult clinical-surgical ICU, at tertiary public hospital in Rio de Janeiro, from August 2015 through March 2017.

Results

Among the total of 629 ICU admissions followed by 7797 patient-days, after applying inclusion and exclusion criteria we identified 184 patients who developed recurrent or single hospital-acquired sepsis. More than 90% of all evaluable cases of sepsis and 87% of control group fulfilled the modified sepsis-3 definition. Non-fermenting bacilli and ventilator-associated pneumonia predominated as etiology and source of CR-GNB sepsis. While Enterobacteriaceae and intra-abdominal surgical site plus urinary-tract infections prevailed in CS-GNB than CR-GNB sepsis. Carbapenemase production was estimated in 76% of CR-GNB isolates. Multivariate logistic regression analysis revealed previous infection (mostly hospital-acquired bacterial infection or sepsis) (OR = 4.28; 95% CI 1.77–10.35), mechanical ventilation (OR = 4.21; 95% CI 1.17–15.18), carbapenem use (OR = 3.42; 95% CI 1.37–8.52) and length of hospital stay (OR = 1.03; 95% CI 1.01–1.05) as independent risk factors for sepsis by CR-GNB. While ICU readmission (OR = 6.92; 95% CI 1.72–27.78) and nosocomial diarrhea (OR = 5.32; 95% CI 1.07–26.45) were factors associated with CS-GNB sepsis.

Conclusions

The investigation of recurrent and not only bacteremic episodes of sepsis was the differential of this study. The results are in agreement with the basic information in the literature. This may help improve management strategies and future studies on sepsis by CR-GNB.

Impact of Clostridioides difficile infection on the outcome of patients receiving a hematopoietic stem cell transplantation

OBJECTIVES

Clostridioides difficile infections (CDI) are common in autologous (auto-HSCT) or allogenic hematopoietic stem cell transplant (allo-HSCT) recipients. However, the impact of CDI on patient outcomes is controversial. We conducted this study to examine the impact of CDI on patient outcomes.

METHODS

We performed a retrospective single-center study, including 191 lymphoma patients receiving an auto-HSCT and 276 acute myeloid leukemia (AML) patients receiving an allo-HSCT. The primary endpoint was overall survival (OS). Secondary endpoints were causes of death and, for the allo-HSCT cohort, GvHD- and relapse-free survival (GRFS).

RESULTS

The prevalence of CDI was 17.6% in the AML allo-HSCT and 7.3% in the lymphoma auto-HSCT cohort. A higher prevalence of bloodstream infections, but no differences concerning OS or cause of death were found for patients with CDI in the auto-HSCT cohort. [AU] In the allo-HSCT cohort, OS and GRFS were similar between CDI and non-CDI patients. However, the leading cause of death was relapse among non-CDI patients, but it was infectious diseases in the CDI group with fewer deaths due to relapse.

CONCLUSIONS

CDI was not associated with worse survival in patients receiving a hematopoietic stem cell transplantation, and there were even fewer relapse-related deaths in the AML allo-HSCT cohort.

Review of high dose vancomycin in the treatment of Clostridioides difficile infection

BACKGROUND

Guidelines recommend oral vancomycin as first-line therapy for Clostridioides difficile infection. Guideline recommendations vary regarding dosing of vancomycin. Our aim was to summarize the current evidence on the efficacy and adverse effects of high dose oral and vancomycin retention enema (>500 mg/day) for the treatment of C. difficile infection.

METHODS

We searched clinical studies and major guidelines in the English language using MEDLINE, the Cochrane Library and Embase from 1985 until 15 April 2020.

RESULTS

No evidence supports the use of high dose oral vancomycin in the treatment of severe C. difficile infection. Weak evidence from observational studies supports the use of high dose oral vancomycin in addition to intravenous metronidazole and high dose vancomycin retention enema in fulminant C. difficile infection. Vancomycin retention enema can be used in severe C. difficile infection when oral administration is not possible, or in conditions when the oral formulation cannot reach the colon such as Hartman's pouch, ileostomies, or colon diversions.

CONCLUSIONS

The dosing schedules for oral vancomycin and vancomycin enemas are not clearly defined due to widely varying results in clinical studies. Large, comparative multicenter trials are urgently needed to define the role of high dose vancomycin in C. difficile infection.

Presence of Clostridioides difficile and multidrug-resistant healthcare-associated pathogens in stool specimens from hospitalized patients in the USA

BACKGROUND

Healthcare-associated infections (HCAIs) continue to be a major cause of morbidity and mortality. Many HCAI pathogens, including multidrug-resistant organisms (MDROs), colonize the gastrointestinal tract.

AIM

To determine the frequency of MDRO carriage in patients who do and do not harbour toxigenic Clostridioides difficile in their stools.

METHODS

Stool specimens received from nine US laboratories were cultured using media selective for C. difficile, Staphylococcus aureus, vancomycin-resistant enterococci (VRE), and carbapenem-resistant Gram-negative organisms (CROs). Specimens and isolates were also tested by polymerase chain reaction (PCR). Bacterial isolates underwent susceptibility testing and genotyping.

FINDINGS

Among 363 specimens, 175 yielded toxigenic C. difficile isolates spanning 27 PCR ribotypes. C. difficile (TCD⁺) stools harboured an additional 28 organisms, including six CROs (3.4%), of which two (1.1%) were carbapenemase-producing organisms (CPOs), 19 VRE (10.9%), and three meticillin-resistant S. aureus isolates (MRSA, 1.7 %). Stools that were culture negative for toxigenic C. difficile (TCD^-) yielded 26 organisms, including four CROs (2.1%), 20 VRE (10.6), and two MRSA (1.1%). Excluding C. difficile, no significant differences were seen in the rates of the MDROs between TCD⁺ and TCD^- specimens.

CONCLUSION

Overall, 15.4% of the TCD⁺ stools and 11.2% of the TCD^- stools carried at least one non-C. difficile MDRO pathogen, indicating that multiple MDROs may be present in the gastrointestinal tracts of patients, including those that harbour C. difficile.

A Tale of Two Healthcare-associated Infections: Clostridium difficile Coinfection Among Patients With Candidemia

Candidemia and Clostridium difficile infection (CDI) are important healthcare-associated infections that share certain risk factors. We sought to describe candidemia-CDI coinfection using population-based surveillance data. We found that nearly 1 in 10 patients with candidemia had CDI coinfection.

Persistent Systemic Microbial Translocation, Inflammation, and Intestinal Damage During Clostridioides difficile Infection

BACKGROUND

Clostridioides difficile infection (CDI) might be complicated by the development of nosocomial bloodstream infection (n-BSI). Based on the hypothesis that alteration of the normal gut integrity is present during CDI, we evaluated markers of microbial translocation, inflammation, and intestinal damage in patients with CDI.

METHODS

Patients with documented CDI were enrolled in the study. For each subject, plasma samples were collected at T0 and T1 (before and after CDI therapy, respectively), and the following markers were evaluated: lipopolysaccharide-binding protein (LPB), EndoCab IgM, interleukin-6, intestinal fatty acid binding protein (I-FABP). Samples from nonhospitalized healthy controls were also included. The study population was divided into BSI+/BSI- and fecal microbiota transplantation (FMT) +/FMT- groups, according to the development of n-BSI and the receipt of FMT, respectively.

RESULTS

Overall, 45 subjects were included; 8 (17.7%) developed primary n-BSI. Markers of microbial translocation and intestinal damage significantly decreased between T0 and T1, however, without reaching values similar to controls (P < .0001). Compared with BSI-, a persistent high level of microbial translocation in the BSI+ group was observed. In the FMT+ group, markers of microbial translocation and inflammation at T1 tended to reach control values.

CONCLUSIONS

CDI is associated with high levels of microbial translocation, inflammation, and intestinal damage, which are still present at clinical resolution of CDI. The role of residual mucosal perturbation and persistence of intestinal cell damage in the development of n-BSI following CDI, as well as the possible effect of FMT in the restoration of mucosal integrity, should be further investigated.

Incidence of Bloodstream Infections, Length of Hospital Stay, and Survival in Patients With Recurrent Clostridioides difficile Infection Treated With Fecal Microbiota Transplantation or Antibiotics: A Prospective Cohort Study

BACKGROUND

Clostridioides difficile infection (CDI) is a risk factor for bloodstream infection (BSI). Fecal microbiota transplantation (FMT) is more effective than antibiotics in treating recurrent CDI, but its efficacy in preventing CDI-related BSI is uncertain.

OBJECTIVE

To assess incidence of primary BSI in patients with recurrent CDI treated with FMT versus antibiotics.

DESIGN

Prospective cohort study. Patients treated with FMT and those treated with antibiotics were matched on propensity score.

SETTING

Single academic medical center.

PATIENTS

290 inpatients with recurrent CDI (57 patients per treatment in matched cohort).

INTERVENTION

FMT or antibiotics.

MEASUREMENTS

The primary outcome was primary BSI within 90 days. Secondary outcomes were length of hospitalization and overall survival (OS) at 90 days.

RESULTS

Of the 290 patients, 109 were treated with FMT and 181 received antibiotics. Five patients in the FMT group and 40 in the antibiotic group developed BSI. Because of differences in the patients treated with FMT versus antibiotics in many baseline characteristics, including number of recurrences and CDI severity, comparative analyses were limited to the matched cohort. Risk for BSI was 23 percentage points (95% CI, 10 to 35 percentage points) lower in the FMT group; the FMT group also had 14 fewer days of hospitalization (CI, 9 to 20 fewer days) and a 32-percentage point increase in OS (CI, 16 to 47 percentage points) compared with the antibiotic group.

LIMITATION

Nonrandomized study with potential for unmeasured or residual confounding; limited generalizability of the propensity score-matched cohort.

CONCLUSION

In a propensity score-matched cohort, patients with recurrent CDI treated with FMT were less likely to develop primary BSI.

PRIMARY FUNDING SOURCE

None.

Impact of Initial Antifungal Therapy on the Outcome of Patients With Candidemia and Septic Shock Admitted to Medical Wards: A Propensity Score-Adjusted Analysis

Background

Echinocandins are recommended as firstline therapy in patients with candidemia. However, there is debate on their efficacy in survival outcomes. The aim of this study is to evaluate whether the choice of initial antifungal therapy improves mortality in patients with candidemia in relation to the presence of septic shock.

Methods

Patients with candidemia hospitalized in internal medicine wards of 5 tertiary care centers were included in the study (December 2012–December 2014). Patient characteristics, therapeutic interventions, and outcome were reviewed. Propensity score (PS) was used as a covariate of the multivariate analysis to perform a stratified analysis according to PS quartiles and to match patients receiving “echinocandins” or “azoles.”

Results

Overall, 439 patients with candidemia were included in the study. A total of 172 (39.2%) patients had septic shock. Thirty-day mortality was significantly higher in patients with septic shock (45.3%) compared with those without septic shock (31.5%; P = .003). Among patients with septic shock, the use of echinocandins in the first 48 hours, compared with azoles, did not affect 30-day mortality in the PS-adjusted Cox regression analysis (hazard ratio [HR], 0.77; 95% confidence interval [CI], 0.37–1.59; P = .48), the PS-stratified analysis, or the logistic regression model in matched cohorts (adjusted HR, 0.92; 95% CI, 0.51–1.63; P = .77).

Conclusions

Echinocandin therapy seems not to improve the outcome of non–intensive care unit patients with septic shock due to candidemia. These findings support the urgent need of further studies in this patient population.

Updates in the epidemiology and management of candidemia and Clostridioides difficile coinfection

Introduction: In recent years, more and more studies have focused on the association between candidemia and Clostridioides difficile infection (CDI), highlighting the risk of subsequent candidemia in patients with CDI. However, a more recent model focuses on the Candida-Clostridioides difficile coinfection as a clinical entity in which candidemia could occur before or after the CDI episode. Areas covered: In this review we analyzed the physiopathological mechanisms underlying the Candida-Clostridioides difficile coinfection, both in case of candidemia preceding and following the CDI. We highlighted that gut alterations occurring during a CDI play a crucial role in the risk of subsequent candidemia. Moreover, we identified areas of interest about the management of Candida-Clostridioides difficile coinfection and proposed answers to relevant clinical questions. Expert opinion: The evaluation of risk factors for candidemia in patients with CDI and the rational antibiotic use in patients with candidemia remain the most efficacious and cost-free instruments to optimally manage the Candida-Clostridioides difficile coinfection. However, further studies are required to cover some unmet needs, such as the development of rapid diagnostic methods of candidemia and the use of new available drugs with minimal effect on the microbiome biodiversity in patients with CDI at high risk of fungemia.

Early alert from the microbiology laboratory improves the outcome of elderly patients with Enterococcus spp. bloodstream infection: Results from a multicentre prospective study

OBJECTIVES

This study describes the clinical features and outcomes of patients with bloodstream infection (BSI) due to Enterococcus spp. and identified factors predictive of mortality.

METHODS

This analysis is part of a prospective multicentre observational study of consecutive hospitalised patients with BSI conducted from March 2012 to December 2012 in 31 internal medicine wards in Italy. Patients with enterococcal BSI were selected from the entire cohort. Patient characteristics, therapeutic interventions and outcome were reviewed. Cox regression analysis was performed to identify factors associated with in-hospital mortality. Hazard ratios (HRs) and 95% interval confidences (CIs) were calculated.

RESULTS

Among 533 patients with BSI, 41 (7.7%) had BSI by Enterococcus spp. (28 Enterococcus faecalis, 4 Enterococcus faecium and 3 each of Enterococcus avium, Enterococcus casseliflavus and Enterococcus gallinarum). Six BSIs (14.6%) were polymicrobial. Median (IQR) patient age was 73 (66-85.5) years. In-hospital mortality was 24.4%. Polymicrobial infection (HR = 9.100, 95% CI 1.295-63.949; P = 0.026), age (HR = 1.261, 95% CI 1.029-1.546; P = 0.025) and SOFA score (HR = 1.244, 95% CI 1.051-1.474; P = 0.011) were risk factors for in-hospital mortality. Conversely, receiving an alert from the microbiology laboratory before obtaining final antimicrobial susceptibility results was associated with survival (HR = 0.073, 95% CI 0.007-0.805; P = 0.033).

CONCLUSION

BSI due to Enterococcus spp. in elderly patients is associated with high mortality. Polymicrobial infection, age and SOFA score are factors associated with poor outcome. Conversely, early alert from the microbiology laboratory improves patient survival.

Risk factors for recurrence in patients with Clostridium difficile infection due to 027 and non-027 ribotypes

OBJECTIVES

Our objective was to evaluate factors associated with recurrence in patients with 027+ and 027- Clostridium difficile infection (CDI).

METHODS

Patients with CDI observed between January and December 2014 in six hospitals were consecutively included in the study. The 027 ribotype was deduced by the presence of tcdB, tcdB, cdt genes and the deletion Δ117 in tcdC (Xpert® C. difficile/Epi). Recurrence was defined as a positive laboratory test result for C. difficile more than 14 days but within 8 weeks after the initial diagnosis date with reappearance of symptoms. To identify factors associated with recurrence in 027+ and 027- CDI, a multivariate analysis was performed in each patient group. Subdistributional hazard ratios (sHRs) and 95% confidence intervals (95%CIs) were calculated.

RESULTS

Overall, 238 patients with 027+ CDI and 267 with 027- CDI were analysed. On multivariate analysis metronidazole monotherapy (sHR 2.380, 95%CI 1.549-3.60, p <0.001) and immunosuppressive treatment (sHR 3.116, 95%CI 1.906-5.090, p <0.001) were factors associated with recurrence in patients with 027+ CDI. In this patient group, metronidazole monotherapy was independently associated with recurrence in both mild/moderate (sHR 1.894, 95%CI 1.051-3.410, p 0.033) and severe CDI (sHR 2.476, 95%CI 1.281-4.790, p 0.007). Conversely, non-severe disease (sHR 3.704, 95%CI 1.437-9.524, p 0.007) and absence of chronic renal failure (sHR 16.129, 95%CI 2.155-125.000, p 0.007) were associated with recurrence in 027- CDI.

CONCLUSIONS

Compared to vancomycin, metronidazole monotherapy appears less effective in curing CDI without relapse in the 027+ patient group, independently of disease severity.

Management of candidemia in patients with Clostridium difficile infection

INTRODUCTION

Patients with C. difficile infection (CDI) experience intestinal microflora changes that can promote the overgrowth and subsequent translocation of gut resident pathogens into the blood. Consistently, CDI due to PCR-ribotype 027 strain, severe or relapsing CDI, and treatment with high-dosage vancomycin are independent risk factors for candidemia.

AREAS COVERED

We review the role played by the gut microbiota during CDI and its treatment, as well as the clinical profile of CDI patients who are at risk of developing candidemia. Also, we discuss the management of these patients by focusing on pre-emptive strategies aimed at reducing the risk of candidemia, and on innovative anti-C. difficile therapies that may mitigate CDI-related effects such as the altered gut microbiota composition and prolonged intestinal mucosa damage. Expert commentary: A closer clinical and diagnostic monitoring of patients with CDI should help to limit the CDI-associated long-term consequences, including Candida infections, which worsen the outcome of hospitalized patients.

Candida endocarditis: systematic literature review from 1997 to 2014 and analysis of 29 cases from the Italian Study of Endocarditis

INTRODUCTION

Candida Endocarditis (CE) is a deadly disease. It is of paramount importance to assess risk factors for acquisition of both Candida native (NVE) and prosthetic (PVE) valve endocarditis and relate clinical features and treatment strategies with the outcome of the disease. Areas covered: We searched the literature using the Pubmed database. Cases of CE from the Italian Study on Endocarditis (SEI) were also included. Overall, 140 cases of CE were analyzed. Patients with a history of abdominal surgery and antibiotic exposure had higher probability of developing NVE than PVE. In the PVE group, time to onset of CE was significantly lower for biological prosthesis compared to mechanical prosthesis. In the whole population, greater age and longer time to diagnosis were associated with increased likelihood of death. Patients with effective anti-biofilm treatment, patients who underwent cardiac surgery and patients who were administered chronic suppressive antifungal treatment showed increased survival. For PVE, moderate active anti-biofilm and highly active anti-biofilm treatment were associated with lower mortality. Expert commentary: Both NVE and PVE could be considered biofilm-related diseases, pathogenetically characterized by Candida intestinal translocation and initial transient candidemia. Cardiac surgery, EAB treatment and chronic suppressive therapy might be crucial in increasing patient survival.

Assessment of risk factors for candidemia in non-neutropenic patients hospitalized in Internal Medicine wards: A multicenter study

BACKGROUND

An increasing prevalence of candidemia has been reported in Internal Medicine wards (IMWs). The aim of our study was to identify risk factors for candidemia among non-neutropenic patients hospitalized in IMWs.

METHODS

A multicenter case-control study was performed in three hospitals in Italy. Patients developing candidemia (cases) were compared to patients without candidemia (controls) matched by age, time of admission and duration of hospitalization. A logistic regression analysis identified risk factors for candidemia, and a new risk score was developed. Validation was performed on an external cohort of patients.

RESULTS

Overall, 951 patients (317 cases of candidemia and 634 controls) were included in the derivation cohort, while 270 patients (90 patients with candidemia and 180 controls) constituted the validation cohort. Severe sepsis or septic shock, recent Clostridium difficile infection, diabetes mellitus, total parenteral nutrition, chronic obstructive pulmonary disease, concomitant intravenous glycopeptide therapy, presence of peripherally inserted central catheter, previous antibiotic therapy and immunosuppressive therapy were factors independently associated with candidemia. The new risk score showed good area under the curve (AUC) values in both derivation (AUC 0.973 95% CI 0.809-0.997, p<0.001) and validation cohort (0.867 95% CI 0.710-0.931, p<0.001). A threshold of 3 leads to a sensitivity of 87% and a specificity of 83%.

CONCLUSION

Non-neutropenic patients admitted in IMWs have peculiar risk factors for candidemia. A new risk score with a good performance could facilitate the identification of candidates to early antifungal therapy.

Invasive listeriosis in a patient with several episodes of antibiotic associated colitis presumably due to Clostridium difficile

A 62-year-old man developed a blood stream infection and meningitis due to Listeria monocytogenes, 20 days after an episode of pseudo-membranous colitis. The patient, hospitalized for the first time for transurethral prostatectomy, was readmitted 20 days later with watery diarrhea. Pseudo-membranous colitis was diagnosed and treated successfully, without testing for Clostridium difficile infection (CDI). After 15 more days, the patient developed again diarrhea, fever and confusion. Hospitalized again, blood and cerebrospinal fluid cultures resulted positive for L. monocytogenes. The patient was treated successfully and a diagnosis of recurrent CDI was confirmed following culture and nucleic acid amplification assays both positive for C. difficile. This is the first report of an invasive listeriosis after CDI underlines the importance of taking greater awareness in complicated blood stream infections that may arise after CDI.

Short- and long-term effects of oral vancomycin on the human intestinal microbiota

BACKGROUND

Oral vancomycin remains the mainstay of therapy for severe infections produced by Clostridium difficile, the most prevalent cause of healthcare-associated infectious diarrhoea in developed countries. However, its short- and long-term effects on the human intestinal microbiota remain largely unknown.

METHODS

We utilized high-throughput sequencing to analyse the effects of vancomycin on the faecal human microbiota up to 22 weeks post-antibiotic cessation. The clinical relevance of the observed microbiota perturbations was studied in mice.

RESULTS

During vancomycin therapy, most intestinal microbiota genera and operational taxonomic units (OTUs) were depleted in all analysed subjects, including all baseline OTUs from the phylum Bacteroidetes. This was accompanied by a vast expansion of genera associated with infections, including Klebsiella and Escherichia/Shigella. Following antibiotic cessation, marked differences in microbiota resilience were observed among subjects. While some individuals recovered a microbiota close to baseline composition, in others, up to 89% of abundant OTUs could no longer be detected. The clinical relevance of the observed microbiota changes was further demonstrated in mice, which developed analogous microbiota alterations. During vancomycin treatment, mice were highly susceptible to intestinal colonization by an antibiotic-resistant pathogen and, upon antibiotic cessation, a less-resilient microbiota allowed higher levels of pathogen colonization.

CONCLUSIONS

Oral vancomycin induces drastic and consistent changes in the human intestinal microbiota. Upon vancomycin cessation, the microbiota recovery rate varied considerably among subjects, which could influence, as validated in mice, the level of susceptibility to pathogen intestinal colonization. Our results demonstrate the negative long-term effects of vancomycin, which should be considered as a fundamental aspect of the cost-benefit equation for antibiotic prescription.