Characterization of Healthcare-Associated and Community-Associated Clostridioides difficile Infections among Adults, Canada, 2015-2019

Dogs in Rio de Janeiro as reservoirs of Clostridioides difficile ribotypes causing CDI in humans

INTRODUCTION

In the past decade, the incidence of community-acquired Clostridioides difficile infection (CA-CDI) has increased, suggesting a role for community reservoirs such as animals in its spread.

OBJECTIVE

This study aimed to isolate and characterize C. difficile strains from domestic dogs at veterinary clinics to enhance our understanding of C. difficile epidemiology in Rio de Janeiro.

MATERIAL AND METHODS

For this study 90 stool samples from dogs were collected and cultured in a selective medium (Clostridioides difficile Brucella agar - CDBA) for isolation. Species were identified by MALDI-TOF MS, with confirmation provided by PCR targeting the tpi gene. The antibiotic susceptibility test of the strains was performed using five antibiotics: vancomycin, metronidazole, moxifloxacin, rifampicin, and erythromycin. Strains resistant to metronidazole were further analyzed for the presence of the plasmid pCD-METRO using PCR. The presence of toxin genes (tcdA, tcdB, and cdtB) was investigated, alongside ribotyping and tcdC sequencing analyses. The strains were also tested for biofilm formation and motility.

RESULTS

C. difficile was isolated in 15.5 % (14/90) of the samples. Among the strains analyzed, 87.71 % (12/14) tested positive for both toxin genes tcdA and tcdB and belonged to ribotypes 106 (10/14) and 014/020 (2/14). The remaining 14.3 % (2/14) were non-toxigenic and were identified as ribotype 010. Regarding the antibiotic profile, 42.85 % (6/14) of the strains exhibited resistance to at least one antibiotic, including vancomycin (1/14) and metronidazole (1/14). The metronidazole-resistant strain was also positive for the plasmid pCD-METRO. All strains exhibited both biofilm formation and motility. Among the 12 toxigenic strains sequenced for the tcdC gene, two exhibited a deletion in the same region as the epidemic strain, NAP1 (RT027).

CONCLUSION

Our study found some overlap between C. difficile ribotypes isolated from dogs and from cases of CDI in humans, and the C. difficile prevalence was higher in dogs with diarrhea (p = 0.034).

Virulence factors, antibiotic susceptibility and sequence type distribution of hospital-associated Clostridioides difficile isolates in Israel, 2020-2022

Biofilm formation and toxin production are some of the virulence factors of Clostridioides difficile (C. difficile), which causes hospital-acquired C. difficile infection (HA-CDI). This work investigated the prevalence and distribution of different strains recovered from HA-CDI patients hospitalized in 4 medical centres across Israel, and characterized strains' virulence factors and antibiotic susceptibility. One-hundred and eighty-eight faecal samples were collected. C. difficile 's toxins were detected by the CerTest Clostridium difficile GDH + Toxin A + B combo card test kit. Toxin loci PaLoc and PaCdt were detected by whole-genome sequencing (WGS). Multi-locus sequence typing (MLST) was performed to classify strains. Biofilm production was assessed by crystal violet. Antibiotic susceptibility was determined using Etest. Fidaxomicin susceptibility was tested via agar dilution. Sequence type (ST) 42 was the most (13.8%) common strain. All strains harboured the 2 toxins genes; 6.9% had the binary toxin. Most isolates were susceptible to metronidazole (98.9%) and vancomycin (99.5%). Eleven (5.85%) isolates were fidaxomicin-resistant. Biofilm production capacity was associated with ST (p < 0.001). In conclusion, a broad variety of C. difficile strains circulate in Israel's medical centres. Further studies are needed to explore the differences and their contribution to HA-CDI epidemiology.

Prescribing Trends for Oral Vancomycin and Fidaxomicin after Guideline and Formulary Changes in Ontario, Canada: An Interrupted Time-Series Analysis

Background

Clostridioides difficile is a pathogen causing diarrheal illness, which can be treated with vancomycin or fidaxomicin.

Objective

To evaluate changes in monthly prescription volumes for oral vancomycin and fidaxomicin in Ontario community pharmacies following implementation of the 2017 and 2021 updates to guidelines from the Infectious Diseases Society of America (IDSA) and Society for Healthcare Epidemiology of America (SHEA) and after a 2019 provincial formulary change for vancomycin.

Methods

An interrupted time-series analysis was conducted from November 2015 to October 2021 using monthly projected prescription volumes obtained from IQVIA's Compuscript database. Level and slope (trend) changes in prescribing were assessed using segmented linear regression.

Results

The volume of vancomycin prescriptions increased by 74 prescriptions per month (95% confidence interval [CI] 16 to 132) following implementation of the 2017 guideline update and by 73 prescriptions per month (95% CI 13 to 133) after the 2019 formulary change; however, no statistically significant changes were observed after implementation of the 2021 guideline update. No significant trend changes were observed for fidaxomicin.

Conclusion

Guidelines and formulary changes were correlated with increased volume of vancomycin prescriptions.

Review article: The epidemiology and management of Clostridioides difficile infection-A clinical update

BACKGROUND

Clostridioides difficile is the most common cause of healthcare-associated infection, and severe cases can result in significant complications. While anti-microbial therapy is central to infection management, adjunctive therapies may be utilised as preventative strategies.

AIM

This article aims to review updates in the epidemiology, diagnosis, and management, including treatment and prevention, of C. difficile infections.

METHODS

A narrative review was performed to evaluate the current literature between 1986 and 2023.

RESULTS

The incidence of C. difficile infection remains significantly high in both hospital and community settings, though with an overall decline in recent years and similar surveillance estimates globally. Vancomycin and fidaxomicin remain the first line antibiotics for treatment of non-severe C. difficile infection, though due to lower recurrence rates, infectious disease society guidelines now favour use of fidaxomicin. Faecal microbiota transplantation should still be considered to prevent recurrent C. difficile infection. However, in the past year the field has had a significant advancement with the approval of the first two live biotherapeutic products-faecal microbiota spores-live brpk, an oral capsule preparation, and faecal microbiota live-jslm-both indicated for the prevention of recurrent C. difficile infection, with additional therapies on the horizon.

CONCLUSION

Although the prevalence of C. difficile infection remains high, there have been significant advances in the development of novel therapeutics and preventative measures following changes in recent practice guidelines, and will continue to evolve in the future.

Ribotypes and antimicrobial susceptibility profiles of clinical Clostridioides difficile isolates: A multicenter, laboratory-based surveillance in Taiwan, 2019-2021

BACKGROUND

The clinical burden of Clostridioides difficile infections (CDIs) remains substantial globally. This study aimed to investigate the ribotypes (RTs) and antimicrobial susceptibility of C. difficile isolates collected in Taiwan.

METHODS

C. difficile isolates were prospectively collected from four medical centers in Taiwan from 2019 to 2021. In a reference laboratory, in vitro susceptibility to clindamycin, moxifloxacin, metronidazole, vancomycin, fidaxomicin, and rifaximin were tested, and ribotyping was conducted to determine their genetic diversity.

RESULTS

A total of 568 C. difficile isolates were included. Metronidazole resistance was not observed, and the susceptibility rate of vancomycin was 99.5 %. Clindamycin showed poor activity against these isolates, with a resistance rate of 74.8 %. Fidaxomicin exhibited potent activity and 97.4 % of isolates were inhibited at 0.25 μg/mL. Rifaximin MIC90 increased from 0.015 μg/mL in 2019 to 0.03 μg/mL in 2020 and 2021. Of 40 RTs identified, two predominant RTs were RT 078/126 (78, 14 %) and 014/020 (76, 13 %). RT 017, traditional harboring truncated tcdA, accounted for 3 % (20 isolates) and there was no isolate belonging to RT 027. The proportions of RT 078 increased from 11.2 % in 2019 to 17.1 % in 2021, and the predominance of RT 078/126 was more evident in central Taiwan.

CONCLUSIONS

Vancomycin, fidaxomicin, and metronidazole remain in vitro effective against clinical C. difficile isolates in Taiwan. The reservoirs and genetic relatedness of two major RTs with zoonotic potentials, RT 078/126 and 014/020, warrant further investigations.

Culture-independent detection of low-abundant Clostridioides difficile in environmental DNA via PCR

Clostridioides difficile represents a major burden to public health. As a well-known nosocomial pathogen whose occurrence is highly associated with antibiotic treatment, most examined C. difficile strains originated from clinical specimen and were isolated under selective conditions employing antibiotics. This suggests a significant bias among analyzed C. difficile strains, which impedes a holistic view on this pathogen. In order to support extensive isolation of C. difficile strains from environmental samples, we designed a detection PCR that targets the hpdBCA-operon and thereby identifies low abundances of C. difficile in environmental samples. This operon encodes the 4-hydroxyphenylacetate decarboxylase, which catalyzes the production of the antimicrobial compound para-cresol. Amplicon-based analyses of diverse environmental samples demonstrated that the designed PCR is highly specific for C. difficile and successfully detected C. difficile despite its absence in general 16S rRNA gene-based detection strategies. Further analyses revealed the potential of the hpdBCA detection PCR sequence for initial phylogenetic classification, which allows assessment of C. difficile diversity in environmental samples via amplicon sequencing. Our findings furthermore showed that C. difficile strains isolated under antibiotic treatment from environmental samples were originally dominated by other strains according to PCR amplicon results. This provided evidence for selective cultivation of under-represented but antibiotic-resistant isolates. Thereby, we revealed a substantial bias in C. difficile isolation and research.IMPORTANCEClostridioides difficile is a main cause of diarrheic infections after antibiotic treatment with serious morbidity and mortality worldwide. Research on this pathogen and its virulence has focused on bacterial isolation from clinical specimens under antibiotic treatment, which implies a substantial bias in isolated strains. Comprehensive studies, however, require an unbiased strain collection, which is accomplished by isolation of C. difficile from diverse environmental samples and avoidance of antibiotic-based enrichment strategies. Thus, isolation can significantly benefit from our C. difficile-specific detection PCR, which rapidly verifies C. difficile presence in environmental samples and further allows estimation of the C. difficile diversity by using next-generation sequencing.

The Strain and the Clinical Outcome of Clostridioides difficile Infection: A Meta-analysis

Background

The association between bacterial strains and clinical outcomes in Clostridioides difficile infection (CDI) has yielded conflicting results across studies. We conducted a systematic review and meta-analyses to assess the impact of these strains.

Methods

Five electronic databases were used to identify studies reporting CDI severity, complications, recurrence, or mortality according to strain type from inception to June 2022. Random effect meta-analyses were conducted to assess outcome proportions and risk ratios (RRs).

Results

A total of 93 studies were included: 44 reported recurrences, 50 reported severity or complications, and 55 reported deaths. Pooled proportions of complications were statistically comparable between NAP1/BI/R027 and R001, R078, and R106. Pooled attributable mortality was 4.8% with a gradation in patients infected with R014/20 (1.7%), R001 (3.8%), R078 (5.3%), and R027 (10.2%). Higher 30-day all-cause mortality was observed in patients infected with R001, R002, R027, and R106 (range, 20%-25%).NAP1/BI/R027 was associated with several unfavorable outcomes: recurrence 30 days after the end of treatment (pooled RR, 1.98; 95% CI, 1.02-3.84); admission to intensive care, colectomy, or CDI-associated death (1.88; 1.09-3.25); and 30-day attributable mortality (1.96; 1.23-3.13). The association between harboring the binary toxin gene and 30-day all-cause mortality did not reach significance (RR, 1.6 [0.9-2.9]; 7 studies).

Conclusions

Numerous studies were excluded due to discrepancies in the definition of the outcomes and the lack of reporting of important covariates. NAP1/BI/R027, the most frequently reported and assessed strain, was associated with unfavorable outcomes. However, there were not sufficient data to reach significant conclusions on other strains.

Antibiotic Resistances of Clostridioides difficile

The rapid evolution of antibiotic resistance in Clostridioides difficile and the consequent effects on prevention and treatment of C. difficile infections (CDIs) are a matter of concern for public health. Antibiotic resistance plays an important role in driving C. difficile epidemiology. Emergence of new types is often associated with the emergence of new resistances, and most of the epidemic C. difficile clinical isolates is currently resistant to multiple antibiotics. In particular, it is to worth to note the recent identification of strains with reduced susceptibility to the first-line antibiotics for CDI treatment and/or for relapsing infections. Antibiotic resistance in C. difficile has a multifactorial nature. Acquisition of genetic elements and alterations of the antibiotic target sites, as well as other factors, such as variations in the metabolic pathways or biofilm production, contribute to the survival of this pathogen in the presence of antibiotics. Different transfer mechanisms facilitate the spread of mobile elements among C. difficile strains and between C. difficile and other species. Furthermore, data indicate that both genetic elements and alterations in the antibiotic targets can be maintained in C. difficile regardless of the burden imposed on fitness, and therefore resistances may persist in C. difficile population in absence of antibiotic selective pressure.

Trends in Clostridioides difficile infection rates in Canadian hospitals during the coronavirus disease 2019 (COVID-19) pandemic

The coronavirus disease 2019 (COVID-19) pandemic has placed significant burden on healthcare systems. We compared Clostridioides difficile infection (CDI) epidemiology before and during the pandemic across 71 hospitals participating in the Canadian Nosocomial Infection Surveillance Program. Using an interrupted time series analysis, we showed that CDI rates significantly increased during the COVID-19 pandemic.

Insights into the Evolving Epidemiology of Clostridioides difficile Infection and Treatment: A Global Perspective

Clostridioides difficile remains an important public health threat, globally. Since the emergence of the hypervirulent strain, ribotype 027, new strains have been reported to cause C. difficile infection (CDI) with poor health outcomes, including ribotypes 014/020, 017, 056, 106, and 078/126. These strains differ in their geographic distribution, genetic makeup, virulence factors, and antimicrobial susceptibility profiles, which can affect their ability to cause disease and respond to treatment. As such, understanding C. difficile epidemiology is increasingly important to allow for effective prevention measures. Despite the heightened epidemiological surveillance of C. difficile over the past two decades, it remains challenging to accurately estimate the burden and international epidemiological trends given the lack of concerted global effort for surveillance, especially in low- and middle-income countries. This review summarizes the changing epidemiology of C. difficile based on available data within the last decade, highlights the pertinent ribotypes from a global perspective, and discusses evolving treatments for CDI.

Microbiome-Related and Infection Control Approaches to Primary and Secondary Prevention of Clostridioides difficile Infections

Clostridioides difficile infections (CDIs) have decreased in the past years, but since 2021, some hospitals have reported an increase in CDI rates. CDI remains a global concern and has been identified as an urgent threat to healthcare. Although multiple treatment options are available, prevention strategies are more limited. As CDI is an opportunistic infection that arises after the normally protective microbiome has been disrupted, preventive measures aimed at restoring the microbiome have been tested. Our aim is to update the present knowledge on these various preventive strategies published in the past five years (2018-2023) to guide clinicians and healthcare systems on how to best prevent CDI. A literature search was conducted using databases (PubMed, Google Scholar, and clinicaltrials.gov) for phase 2-3 clinical trials for the primary or secondary prevention of CDI and microbiome and probiotics. As the main factor for Clostridium difficile infections is the disruption of the normally protective intestinal microbiome, strategies aimed at restoring the microbiome seem most rational. Some strains of probiotics, the use of fecal microbial therapy, and live biotherapeutic products offer promise to fill this niche; although, more large randomized controlled trials are needed that document the shifts in the microbiome population.

Retrospective Cohort Analysis of Outpatient Antibiotic Use for Clostridioides difficile-Indicated Agents in British Columbia, from 2000 to 2018

Background

Clostridioides difficile (CDI) is the most common cause of nosocomial diarrheal infections. Historically, metronidazole was the first-line treatment, but guidelines now indicate oral vancomycin and fidaxomicin as primary antibiotics for initial episodes. A provincial stewardship program has operated in British Columbia (BC), since 2005. Since the program's inception, surveillance of antibiotic use has been ongoing. However, this is the first study to review community-acquired CDI-indicated antibiotic use. Moreover, this study offers the first interpretation of fidaxomicin use in BC since its addition to the provincial formulary.

Methods

A retrospective cohort analysis included all outpatient dispensations for CDI-related antibiotics from January 1, 2000, to December 31, 2018. Antibiotic dispensations were extracted for metronidazole, vancomycin, and fidaxomicin. Consumption rates were calculated as prescriptions per 1000 population. Rates were examined overall and then stratified by medication, age, and sex. Secondary outcomes of interest included an examination of adherence to provincial special authority criteria; and proportions of outpatient antibiotic use attributable to administrative health records for CDI.

Results

The average annual rate of prescribing was 18.5 per 1000 population for all CDI-indicated antibiotics. The rate of prescribing increased (15%) over the 19-year study period, from 17.2 to 19.8 dispensations per 1000 population. Metronidazole accounted for the most antibiotics dispensed in every study year; however, by 2018 it demonstrated the most modest increase in use (15%). In comparison, fidaxomicin increased by 226% by 2018. Vancomycin had the highest percentage increase (621%), with the greatest change occurring from 2014 to 2015, correlating to the dissemination of new clinical practice guidelines.

Conclusion

This is the first study to evaluate outpatient prescribing for CDI-indicated antibiotics, and one of the few studies to examine fidaxomicin since its introduction to Canadian formularies. Although causation cannot be inferred from study results, oral vancomycin, and fidaxomicin use has increased in line with, or in advance-of guidelines.

Community-onset Clostridioides difficile infection in south Serbia

BACKGROUND

Data from the past decade indicates that Clostridioides difficile infection (CDI) is not only a nosocomial infection but is also increasingly recognized as a disease in the community.

OBJECTIVE

We aimed to study community-onset (CO) CDI in the various age groups in south Serbia with its clinical characteristics, risk factors and microbiological characterization.

METHODS

The study group included 93 patients with CO-CDI (median age 62). The control group consisted of 186 patients with community-onset diarrhea and stool samples negative tested for CDI.

RESULTS

Of all CDI cases diagnosed with a community onset, 74.19% had a previous contact with a healthcare facility in the previous 12 weeks, but 34.40% have no record on hospitalization in the previous 12 months. Using a multivariate statistical regression model, the following risk factors for CO-CDI development were found; antacid usage (OR = 0.267, 95%C.I.:0.10-0.291, p < 0.01), chronic kidney disease (OR = 0.234, 95%C.I.:0.10-0.51, p < 0.01) and antibiotic use during the prior 2 months (OR = 0.061, 95%C.I.:0.02-0.17, p < 0.01), especially tetracycline's (OR = 0.146, 95% C.I.:0.07-0.22, p < 0.01) and cephalosporin's (OR = 0.110, 95%C.I.:0.14-0.42, p < 0.01). The most common ribotypes (RTs) detected in patients with CO-CDI were RT001 (32.3%) and RT027 (24.7%). All tested toxin producing C. difficile isolates were sensitive to metronidazole, vancomycin and tigecycline. A high rate of resistance to moxifloxacin (73.11%) and rifampicin (23.65%) was found.

CONCLUSION

Patients with CO-CDI had frequently contact with healthcare facility in the previous 12 weeks. Restriction of antacid usage and of high-risk antibiotics in the community may help reduce the incidence of CO-CDI.