An Analysis of Clostridium difficile Environmental Contamination During and After Treatment for C difficile Infection

Public health case for microbiome-sparing antibiotics and new opportunities for drug development

Although antibiotics remain a cornerstone of modern medicine, the issues of widespread antibiotic resistance and collateral damage to the microbiome from antibiotic use are driving a need for drug developers to consider more tailored, patient-directed products to avoid antibiotic-induced perturbations of the structure and function of the indigenous microbiota. This perspective summarizes a cascade of microbiome health effects that is initiated by antibiotic-mediated microbiome disruption at an individual level and ultimately leads to infection and transmission of multidrug-resistant pathogens across patient populations. The scientific evidence behind each of the key steps of this cascade is presented. The interruption of this cascade through the use of highly targeted, microbiome-sparing antibiotics aiming to improve health outcomes is discussed. Further, this perspective reflects on some key clinical trial design and reimbursement considerations to be addressed as part of the drug development path.

European Practice for CDI Treatment

Clostridioides difficile infection (CDI) remains a significant cause of morbidity and mortality worldwide. Historically, two antibiotics (metronidazole and vancomycin) and a recent third (fidaxomicin) have been used for CDI treatment; convincing data are now available showing that metronidazole is the least efficacious agent. The European Society of Clinical Microbiology and Infectious Diseases (ESCMID) management guidance for CDI were updated in 2021. This guidance document outlines the treatment options for a variety of CDI clinical scenarios and for non-antimicrobial management (e.g., faecal microbiota transplantation, FMT). One of the main changes is that metronidazole is no longer recommended as first-line CDI treatment. Rather, fidaxomicin is preferred on the basis of reduced recurrence rates with vancomycin as an acceptable alternative. Recommended options for recurrent CDI now include bezlotoxumab as well as FMT.A 2017 survey of 20 European countries highlighted variation internationally in CDI management strategies. A variety of restrictions were in place in 65% countries prior to use of new anti-CDI treatments, including committee/infection specialist approval or economic review/restrictions. This survey was repeated in November 2022 to assess the current landscape of CDI management practices in Europe. Of 64 respondents from 17 countries, national CDI guidelines existed in 14 countries, and 11 have already/plan to incorporate the ESCMID 2021 CDI guidance, though implementation has not been surveyed in 6. Vancomycin is the most commonly used first-line agent for the treatment of CDI (n = 42, 66%), followed by fidaxomicin (n = 30, 47%). Six (9%) respondents use metronidazole as first-line agent for CDI treatment, whereas 22 (34%) only in selected low-risk patient groups. Fidaxomicin is more likely to be used in high-risk patient groups. Availability of anti-CDI therapy influenced prescribing in six respondents (9%). Approval pre-prescription was required before vancomycin (n = 3, 5%), fidaxomicin (n = 10, 6%), bezlotoxumab (n = 11, 17%) and FMT (n = 10, 6%). Implementation of CDI guidelines is rarely audited.Novel anti-CDI agents are being evaluated; it is not yet clear what will be the roles of these agents. The treatment of recurrent CDI is particularly troublesome, and several different live biotherapeutics are being developed, in addition to FMT.

Environmental approaches to controlling Clostridioides difficile infection in healthcare settings

As today's most prevalent and costly healthcare-associated infection, hospital-onset Clostridioides difficile infection (HO-CDI) represents a major threat to patient safety world-wide. This review will discuss how new insights into the epidemiology of CDI have quantified the prevalence of C. difficile (CD) spore contamination of the patient-zone as well as the role of asymptomatically colonized patients who unavoidable contaminate their near and distant environments with resilient spores. Clarification of the epidemiology of CD in parallel with the development of a new generation of sporicidal agents which can be used on a daily basis without damaging surfaces, equipment, or the environment, led to the research discussed in this review. These advances underscore the potential for significantly mitigating HO-CDI when combined with ongoing programs for optimizing the thoroughness of cleaning as well as disinfection. The consequence of this paradigm-shift in environmental hygiene practice, particularly when combined with advances in hand hygiene practice, has the potential for significantly improving patient safety in hospitals globally by mitigating the acquisition of CD spores and, quite plausibly, other environmentally transmitted healthcare-associated pathogens.

The Hospital Environment as a Potential Source for Clostridioides difficile Transmission Based on Spore Detection Surveys Conducted at Paediatric Oncology and Gastroenterology Units

Clostridioides difficile is an anaerobic, Gram-positive bacterium widely present in the hospital environment due to its ability to generate spores. The transfer of spores to patients through the hands of medical personnel is one of the most frequent paths of C. difficile transmission. In paediatric patients burdened with a serious primary illness requiring long-term hospitalisation and antibiotic therapy, C. difficile may be a significant risk factor for antibiotic-associated diarrhoea. The goal of the study was to assess the state of hospital environments as a potential source of C. difficile spores and to establish the share of hyperepidemic strains at the two paediatric units. The survey for C. difficile was conducted with a C. diff Banana BrothTM medium, used to detect spores and to recover vegetative forms of the bacteria. Environmental samples (n = 86) and swabs from the clothing of medical personnel (n = 14) were collected at two units of a paediatric hospital, where the cases of antibiotic-associated diarrhoea with a C. difficile aetiology constitute a significant clinical problem. In 17 samples, a change in the broth's colour was observed, indicating the presence of spores. Out of seven samples, C. difficile strains were cultured. The pathogenic isolates of C. difficile were obtained from swabs collected from elements of beds, a toilet, a door handle and a doctor's uniform. In our study, we indicated points of increased risk of pathogen transmission, which could constitute a source of infection. The clothing of medical personnel may be a dangerous carrier of pathogenic spores. Periodical surveys of hospital environments with the use of specialist microbiological mediums successfully indicate the direction of corrective actions to be undertaken by the medical facility in order to increase patient safety.

Matching Clostridioides difficile strains obtained from shoe soles of healthcare workers epidemiologically linked to patients and confirmed by whole genome sequencing

BACKGROUND

The source of transmission of Clostridioides difficile in healthcare institutions is frequently unknown. The aim of this prospective cohort study was to assess the association between strains cultured from patients and shoe soles of healthcare workers (HCW), as already shown in the operation theatre, but not on general hospital wards in an acute care institution.

METHODS

We conducted a study at a university tertiary care center in Switzerland. From October 2019 to July 2020, shoe soles of HCW were cultured for C. difficile twice per shift while taking care of a patient infected with toxigenic C. difficile. Additional risk factors were assessed by interviewing involved HCW. Patients' fecal samples were processed by routine microbiological methods. Similarity of the HCWs' and patients' strains was determined by whole genome sequencing (WGS).

RESULTS

103 HCW exposed to 42 hospitalized patients participated in the study, providing 206 samples. Contamination of shoe soles with C. difficile was detected in 37 samples (17.8%) of HCW taking care of patients infected with C. difficile. Overall, transmission was suspected by epidemiological link and matching strains demonstrated by WGS in 74%.

CONCLUSIONS

HCW' shoe soles were positive in 17.8% with C. difficile strains linked epidemiologically and confirmed by WGS to infected patients suggesting potential transmission by HCWs' shoe soles. This pilot study provides sufficient evidence to further evaluate this potential mode of healthcare-associated transmission of C. difficile by a larger clinical trial.

The impact of infection vs. colonization on Clostridioides difficile environmental contamination in hospitalized patients with diarrhea

Background

Patients with Clostridioides difficile infections (CDIs) contaminate the healthcare environment; however, the relative contribution of contamination by colonized individuals is unknown. Current guidelines do not recommend the use of contact precautions for asymptomatic C difficile carriers. We evaluated C difficile environmental contamination in rooms housing adult inpatients with diarrhea based on C difficile status.

Methods

We performed a prospective cohort study of inpatient adults with diarrhea who underwent testing for CDI via polymerase chain reaction (PCR) and enzyme immunoassay (EIA). Patients were stratified into cohorts based on test result: infected (PCR⁺/EIA⁺), colonized (PCR⁺/EIA⁻), or negative/control (PCR⁻). Environmental microbiological samples were taken within 24 hours of C difficile testing and again for 2 successive days. Samples were obtained from the patient, bathroom, and care areas.

Results

We enrolled 94 patients between November 2019 and June 2021. Clostridioides difficile was recovered in 93 (38%) patient rooms: 44 (62%) infected patient rooms, 35 (43%) colonized patient rooms (P = .08 vs infected 38 patient rooms), and 14 (15%) negative patient rooms (P < .01 vs infected; P < .01 vs colonized). Clostridioides difficile was recovered in 40 (56%), 6 (9%), and 20 (28%) of bathrooms, care areas and patient areas in 40 infected patient rooms; 34 (41%), 1 (1%), and 4 (5%) samples in colonized patient rooms; and 12 (13%), 1 (1%), and 3 (3%) of samples in negative patient rooms, respectively.

Conclusions

Patients colonized with C difficile frequently contaminated the hospital environment. Our data support the use of contact precautions when entering rooms of patients colonized with C difficile, especially when entering the bathroom.

Opportunities for Nanomedicine in Clostridioides difficile Infection

Clostridioides difficile, a spore-forming bacterium, is a nosocomial infectious pathogen which can be found in animals as well. Although various antibiotics and disinfectants were developed, C. difficile infection (CDI) remains a serious health problem. C. difficile spores have complex structures and dormant characteristics that contribute to their resistance to harsh environments, successful transmission and recurrence. C. difficile spores can germinate quickly after being exposed to bile acid and co-germinant in a suitable environment. The vegetative cells produce endospores, and the mature spores are released from the hosts for dissemination of the pathogen. Therefore, concurrent elimination of C. difficile vegetative cells and inhibition of spore germination is essential for effective control of CDI. This review focused on the molecular pathogenesis of CDI and new trends in targeting both spores and vegetative cells of this pathogen, as well as the potential contribution of nanotechnologies for the effective management of CDI.

Impact of Oral Metronidazole, Vancomycin, and Fidaxomicin on Host Shedding and Environmental Contamination with Clostridioides difficile

OBJECTIVES

Shedding of Clostridioides difficile spores from infected individuals contaminates the hospital environment and contributes to infection transmission. We assessed whether antibiotic selection impacts C. difficile shedding and contamination of the hospital environment.

METHODS

In this prospective, unblinded, randomized controlled trial of hospitalized adults with C. difficile infection, subjects were randomized 1:1:1 to receive fidaxomicin, oral vancomycin, or metronidazole. The primary outcome was change in environmental contamination rate while on treatment. Secondary outcomes included stool shedding, total burden of contamination, and molecular relatedness of stool versus environmental C. difficile isolates.

RESULTS

33 patients were enrolled and 31 (94%) completed the study. Fidaxomicin (-0.36 log10 CFU/day, 95% CI -0.52 to -0.19, p<0.01) and vancomycin (-0.17 log10 CFU/day, 95% CI -0.34 to -0.01, p=0.05) were associated with more rapid decline in C. difficile shedding compared to metronidazole (-0.01 log10 CFU/day, 95% CI -0.10 to +0.08). Both vancomycin (6.3%, 95% CI 4.7-8.3%) and fidaxomicin (13.1%, 95% CI 10.7-15.9%) were associated with lower rates of environmental contamination than metronidazole (21.4%, 95% CI 18.0-25.2%). When specifically modeling within-subject change over time, fidaxomicin (aOR 0.83, 95% CI 0.70-0.99, p=0.04) was associated with more rapid decline in environmental contamination than vancomycin or metronidazole. Overall, 207 of 233 (88.8%) of environmental C. difficile isolates matched subject stool isolates by ribotyping, without significant difference by treatment.

CONCLUSIONS

Fidaxomicin, and to a lesser extent vancomycin, reduces C. difficile shedding and contamination of the hospital environment relative to metronidazole. Treatment choice may play a role in reducing healthcare-associated C. difficile transmission.