Clostridium difficile as a cause of healthcare-associated diarrhoea among children in Auckland, New Zealand: clinical and molecular epidemiology

Faecal source apportionment using molecular methods: A proof of concept using the FEAST algorithm

Faecal contamination of freshwater and marine environments represents a significant risk for public health, recreational activity and food safety, and tools for evaluating complex multi-source contamination remain largely in the development phase. We evaluated the efficacy of the Fast Expectation Maximization (FEAST) microbial source tracking (MST) algorithm to apportion sources of faecal contamination among four mammalian species of interest in coastal waters in New Zealand. Using 16S ribosomal DNA metabarcoding of faecal samples from cows, fur seals, and sheep, as well as human wastewater, we aimed to differentiate and quantify the contribution of these sources in mixed faecal samples. Multivariate analysis confirmed significant differences in the microbial communities associated with each mammalian source, with specific bacterial classes indicative of different sources. The FEAST algorithm was tested using mixed DNA and mixed faecal samples, and we found that the algorithm correctly assigned the dominant source from all samples, but underestimated the dominant source's proportional contribution. This underestimation suggests the need for further refinement and validation to ensure accurate source apportionment in environmental samples where the faecal signal is likely to be a minor component. Despite these limitations, the findings of our study, in combination with the evidence from others who have tested the FEAST algorithm in environmental settings, indicates that it represents an advance on existing tools for microbial source tracking and may become a useful addition to the toolbox for environmental management.

Make It Less difficile: Understanding Genetic Evolution and Global Spread of Clostridioides difficile

Clostridioides difficile is an obligate anaerobic pathogen among the most common causes of healthcare-associated infections. It poses a global threat due to the clinical outcomes of infection and resistance to antibiotics recommended by international guidelines for its eradication. In particular, C. difficile infection can lead to fulminant colitis associated with shock, hypotension, megacolon, and, in severe cases, death. It is therefore of the utmost urgency to fully characterize this pathogen and better understand its spread, in order to reduce infection rates and improve therapy success. This review aims to provide a state-of-the-art overview of the genetic variation of C. difficile, with particular regard to pathogenic genes and the correlation with clinical issues of its infection. We also summarize the current typing techniques and, based on them, the global distribution of the most common ribotypes. Finally, we discuss genomic surveillance actions and new genetic engineering strategies as future perspectives to make it less difficile.

Risk factors for Clostridioides difficile infection in children: A systematic review and meta-analysis

BACKGROUND

Clostridioides difficile infection (CDI) is considered an urgent threat to human health by the US Centers for Disease Control and Prevention. In recent years, C. difficile is increasingly being reported as a cause of gastrointestinal diseases in children, and the prevalence of hospital-acquired CDI (HA-CDI) and community-acquired CDI (CA-CDI) in children is increasing.

AIM

To perform a systematic review and meta-analysis of risk factors for Clostridioides difficile infection (CDI) in children.

METHODS

MEDLINE/PubMed, EMBASE, Web of Science, Scopus, OVID, China National Knowledge Infrastructure, Wanfang (Chinese), SinoMed (Chinese), and Weipu (Chinese) databases were searched from inception through January 12, 2022. Observational studies (cohort, case-control, and cross-sectional) on CDI in children were included in the analysis. Data were pooled using a fixed or random-effects model, and odds ratios (ORs) were calculated.

FINDINGS

A total of 25 observational studies were included in the analysis. Prior antibiotic exposure (OR, 1.93; 95% confidence interval (CI), 1.25-2.97), prolonged hospitalization (OR, 14.68; 95% CI, 13.24-16.28), hospitalization history (OR, 3.67; 95% CI, 1.91-7.06), gastric acid suppressants (OR, 1.96; 95% CI, 1.41-2.73), male gender (OR, 1.18; 95% CI, 1.05-1.32), neoplastic disease (OR, 3.40; 95% CI, 2.85-4.07), immunodeficiency (OR, 4.18; 95% CI, 3.25-5.37), solid organ transplantation (OR, 4.56; 95% CI, 3.95-5.27) and enteral feeding (OR, 2.21; 95% CI, 1.15-4.62) were associated with an increased risk of CDI.

CONCLUSION

This systematic review and meta-analysis provides further evidence for the susceptibility factors of CDI to improve clinicians' awareness of CDI and effectively prevent C. difficile associated diarrhoea in children.

Clostridioides (Clostridium) difficile isolated from paediatric patients in Western Australia 2019-2020

Less is understood about the epidemiology of Clostridioides difficile infection (CDI) in children compared to adults, and its impact is complicated by variations in the natural development of infection in paediatric patients. The interplay of rising CDI incidence in hospitalised paediatric patients, emergence of hypervirulent strains and community associated CDI (CA-CDI) in the past decade is a potential threat in both hospital and community settings. Research in Australia regarding paediatric CDI is limited. Here, we report the molecular characterisation of C. difficile isolated from paediatric patients at a tertiary hospital in Perth, Western Australia. A total of 427 stool samples was collected from patients aged from <1 to 17 years being investigated for diarrhoea from July 2019 to June 2020. Stool specimens were cultured and isolates of C. difficile characterised by ribotyping and toxin gene profiling. Clostridioides difficile was recovered from 84/427 (19.7%) samples tested. The most prevalent PCR ribotypes (RTs) were RT 002 (12.4%), a toxigenic strain, and RT 009 (15.7%), a non-toxigenic strain. Interestingly, C. difficile RT 078 and RT 017, strains that are not endemic in Australia, were isolated from a 1- and 4-year-old child, respectively. Clostridioides difficile RT 106, a strain of emerging importance in Australia, was recovered from two cases (5.3%). Resistance to metronidazole, fidaxomicin, amoxicillin, rifaximin and meropenem was not detected, however, 45 isolates (50.6%) showed resistance to at least one agent, and multidrug resistance was observed in 13.3% of the resistant isolates (6/45). This study provides a baseline for future surveillance of paediatric CDI in Australia. Given that young children can be asymptomatically colonised with toxigenic C. difficile strains, they represent a potential reservoir of strains causing CDI in adults.

Molecular Epidemiology of Clostridioides difficile Infections in Children

Clostridioides difficile is a prominent cause of health care-related gastrointestinal illness in adults. C. difficile infection (CDI) has been researched for over 40 years; however, research on pediatric CDI specifically has lagged behind for various reasons. Over the past decade, C. difficile has been increasingly reported as a cause of a broad spectrum of gastrointestinal diseases in children, ranging from mild self-limiting diarrhea to severe conditions such as pseudomembranous colitis and toxic megacolon. Recent publications have shown a rise in CDI incidence in children in different parts of the world, especially in patients with particular comorbidities such as hematological malignancies and inflammatory bowel disease. In addition, rising CDI rates have been reported in children in the community without traditional risk factors for CDI. Due to the extensive use of sensitive molecular detection methods to diagnose CDI in many countries, differentiating children who require treatment from those colonized with toxigenic strains remains a problem. Consequently, the molecular epidemiology of pediatric CDI is poorly understood. Even though well-known C. difficile strains causing CDI in children have been described (including hypervirulent strains such as ribotypes 027 and 078), there is a paucity of information about specific C. difficile strains. This mini-review summarizes the information that is currently available on the molecular epidemiology of CDI in children.

Diagnosis and management of paediatric Clostridioides difficile infection in a tertiary centre: A prospective audit

AIM

The optimisation of diagnosis and management of paediatric Clostridioides (formerly Clostridium) difficile (C. difficile) infection (CDI) has importance on multiple levels, from individual patient to population disease management and infection control. This study aimed to evaluate current practice at a paediatric tertiary hospital against Australasian Society for Infectious Diseases 2016 guidelines.

METHODS

Prospective audit was undertaken. All positive C. difficile tests (by two step immunoassay then polymerase chain reaction) over 6 month period were reviewed for appropriateness of testing, including review of clinical characteristics and treatment of appropriately requested positive tests (CDI cases). Consecutive test requests for C. difficile over 2 month period were reviewed for appropriateness of testing.

RESULTS

Of 70 consecutive test requests, 64 met laboratory criteria for processing. Of these, 31 (48%) out of 64 were asymptomatic or had clinically insignificant or laxative-associated diarrhoea. Overall, 44 (63%) out of 70 were deemed inappropriate requests. Of 45 positive tests, 17 (38%) were appropriately requested. Amongst inappropriate requests, 13 (46%) out of 28 were treated; those aged >2 years were significantly more likely to be treated (P < 0.05). Thirteen children were treated unnecessarily. Only one out of seven positive tests in infants (<1 year) was appropriately requested. Haematology/oncology patients accounted for 41% of cases. Treatment was in accordance with guidelines in 58% of cases.

CONCLUSIONS

Inappropriate testing for C. difficile and variable clinical response to positive tests have sequelae including unnecessary antibiotics for hospitalised children. Areas for improvement have been identified and this study confirms the need for establishment of national paediatric CDI guidelines with increased awareness of these by clinicians.

Molecular epidemiology of antimicrobial resistant microorganisms in the 21th century: a review of the literature

Healthcare-associated infections (HAIs) are the most frequent and severe complication acquired in healthcare settings with high impact in terms of morbidity, mortality and costs. Many bacteria could be implicated in these infections, but, expecially multidrug resistance bacteria could play an important role. Many microbial typing technologies have been developed until to the the bacterial whole-genome sequencing and the choice of a molecular typing method therefore will depend on the skill level and resources of the laboratory and the aim and scale of the investigation. In several studies the molecular investigation of pathogens involved in HAIs was performed with many microorganisms identified as causative agents such as Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, Clostridium difficile, Acinetobacter spp., Enterobacter spp., Enterococcus spp., Staphylococcus aureus and several more minor species. Here, we will describe the most and least frequently reported clonal complex, sequence types and ribotypes with their worldwide geographic distribution for the most important species involved in HAIs.

Global burden of Clostridium difficile infections: a systematic review and meta-analysis

Background

Clostridium difficile is a leading cause of morbidity and mortality in several countries. However, there are limited evidence characterizing its role as a global public health problem. We conducted a systematic review to provide a comprehensive overview of C. difficile infections (CDI) rates.

Methods

Seven databases were searched (January 2016) to identify studies and surveillance reports published between 2005 and 2015 reporting CDI incidence rates. CDI incidence rates for health care facility-associated (HCF), hospital onset-health care facility-associated, medical or general intensive care unit (ICU), internal medicine (IM), long-term care facility (LTCF), and community-associated (CA) were extracted and standardized. Meta-analysis was conducted using a random effects model.

Results

229 publications, with data from 41 countries, were included. The overall rate of HCF-CDI was 2.24 (95% confidence interval CI = 1.66-3.03) per 1000 admissions/y and 3.54 (95%CI = 3.19-3.92) per 10 000 patient-days/y. Estimated rates for CDI with onset in ICU or IM wards were 11.08 (95%CI = 7.19-17.08) and 10.80 (95%CI = 3.15-37.06) per 1000 admission/y, respectively. Rates for CA-CDI were lower: 0.55 (95%CI = 0.13-2.37) per 1000 admissions/y. CDI rates were generally higher in North America and among the elderly but similar rates were identified in other regions and age groups.

Conclusions

Our review highlights the widespread burden of disease of C. difficile, evidence gaps, and the need for sustainable surveillance of CDI in the health care setting and the community.

Factors affecting development of Clostridium difficile infection in hospitalized pediatric patients in the country Georgia

OBJECTIVE

Main aims of our study were to investigate occurrence of Clostridium difficile among hospitalized pediatric patients in Georgia and examine risk factors for the development of C. difficile infection. During our study we tested and piloted the real-time PCR diagnostic systems for rapid and simultaneous identification of C. difficile and number of other pathogens in our facility settings. A cross-sectional study has been performed in children less than 18 years of age in two pediatric hospitals in Georgia, between May 2016 and December 2017. Stool specimens negative by the conventional bacteriology analysis were analyzed for the presence of C. difficile and several viral and protozoa pathogens using enzyme immune assay and polymerase chain reaction. In total samples from 220 hospitalized children with gastroenteritis symptoms were analyzed in this study.

RESULTS

The average age of the study participants was 4.7 years. Overall 23 children were identified positive for C. difficile (10.5%). Antibiotic exposure within 2 months preceding the onset of diarrhea was associated with an increased risk of C. difficile infections. The risk was greatest with cephalosporins, followed by penicillins, carbapenems and macrolides. Clostridium difficile is an important cause of healthcare-associated diarrhea in pediatric population of Georgia.

Magnitude and direction of the association between Clostridium difficile infection and proton pump inhibitors in adults and pediatric patients: a systematic review and meta-analysis

BACKGROUND

Clostridium difficile infection (CDI) is a cause of increased morbidity and health care costs among hospitalized patients. Proton pump inhibitors (PPIs) are mainly used for the treatment of acid-related upper gastrointestinal diseases. The aim of the study was to assess the risks associated with initial and recurrent CDI in adult and pediatric patients treated with PPIs.

METHODS

A systematic search was performed using PubMed (Medline), Embase, and Web of Science with the following search terms: ("proton pump inhibitor," "PPI," or "acid suppression") AND ("infection," "diarrhea," "diarrhoea," "colitis," or "disease") AND ("Clostridium difficile"). Meta-analysis was performed using Revman5.3 software. Pooled odds ratios (ORs) presented as standard plots with 95% confidence intervals (CIs) were determined.

RESULTS

Sixty-seven eligible studies were selected. PPI use was significantly associated with risk of CDI (OR 2.34, 95% CI 1.94-2.82; P < 0.00001). Pooled data from twelve studies demonstrated a significant association between PPI use and recurrent CDI (OR 1.73, 95% CI 1.39-2.15; P = 0.02). Subgroup analysis revealed significant associations between PPI use and an increased incidence of CDI among adult (OR 2.30, 95% CI 1.89-2.80; P < 0.00001) and pediatric (OR 3.00, 95% CI 1.44-6.23; P < 0.00001) patients.

CONCLUSIONS

PPI use was associated with CDI in adult and pediatric patients, and with recurrent CDI. Although many risk factors are associated with the occurrence and recurrence of CDI, consideration should be given to not administering PPIs at any age if they are unnecessary.

Clostridium difficile causing pediatric infections: New findings from a hospital-based study in Italy

Recent studies support a change of Clostridium difficile infections (CDIs) epidemiology in pediatric patients. Since limited information is available about C. difficile in this population, we investigated the epidemiology of CDI in a large pediatric hospital that acts as reference centre in Italy and analyzed C. difficile isolates to identify the prevalent PCR-ribotypes (RTs), the binary toxin (CDT)-positive strains and the antibiotic susceptibility patterns. The CDI incidence was 6.6 cases/1000 admissions and the majority (92%) of CDI were healthcare-associated (47% occurred in the Hematology-Oncology and in the Gastroenterology units). Most of symptomatic children <3 years with a positive culture for C. difficile were negative for other gastrointestinal pathogens, supporting C. difficile as cause of disease in these patients, including those showing recurrences. Strains RT020 (16%) and RT014 (14%) were identified as the main cause of infection, while RT356/607 and RT018, predominant in Italian adult patients, were absent (RT356/607) or rarely found (RT018) among children. CDT-positive strains represented the 20% of the total number of isolates analyzed. In particular, two emerging types, RT033 and RT442, were recognized as Toxin A-/Toxin B-/CDT+. Resistance to antibiotics characterized almost 50% of the toxigenic isolates analyzed in this study and, in particular, 20% of them were multidrug resistant (MDR). The emergence and circulation of strains with peculiar toxins profiles and/or MDR strongly highlight the necessity of a rapid CDI diagnosis, a careful monitoring of C. difficile in pediatric patients and a more strict control of antibiotics usage in the Italian pediatric hospitals.

Comparison of pediatric and adult antibiotic-associated diarrhea and Clostridium difficile infections

Antibiotic-associated diarrhea (AAD) and Clostridum difficile infections (CDI) have been well studied for adult cases, but not as well in the pediatric population. Whether the disease process or response to treatments differs between pediatric and adult patients is an important clinical concern when following global guidelines based largely on adult patients. A systematic review of the literature using databases PubMed (June 3, 1978-2015) was conducted to compare AAD and CDI in pediatric and adult populations and determine significant differences and similarities that might impact clinical decisions. In general, pediatric AAD and CDI have a more rapid onset of symptoms, a shorter duration of disease and fewer CDI complications (required surgeries and extended hospitalizations) than in adults. Children experience more community-associated CDI and are associated with smaller outbreaks than adult cases of CDI. The ribotype NAP1/027/BI is more common in adults than children. Children and adults share some similar risk factors, but adults have more complex risk factor profiles associated with more co-morbidities, types of disruptive factors and a wider range of exposures to C. difficile in the healthcare environment. The treatment of pediatric and adult AAD is similar (discontinuing or switching the inciting antibiotic), but other treatment strategies for AAD have not been established. Pediatric CDI responds better to metronidazole, while adult CDI responds better to vancomycin. Recurrent CDI is not commonly reported for children. Prevention for both pediatric and adult AAD and CDI relies upon integrated infection control programs, antibiotic stewardship and may include the use of adjunctive probiotics. Clinical presentation of pediatric AAD and CDI are different than adult AAD and CDI symptoms. These differences should be taken into account when rating severity of disease and prescribing antibiotics.

Healthcare-Associated Clostridium difficile Infections and Strain Diversity in Pediatric Hospitals in the Canadian Nosocomial Infection Surveillance Program, 2007-2011

Children with healthcare-associated Clostridium difficile infection were identified. The incidence increased from 3.2/10,000 patient days in 2007 to 5.2/10,000 patient days in 2011 (p < 0.001). Of 169 isolates, the most common North American Pulsed-Field (NAP) types were NAP4 (n = 43; (25.4%), and NAP1 (n = 25;14.8%) while 55 (32.6%) were non-assigned NAP types.

Use of Acid Suppression Medication is Associated With Risk for C. difficile Infection in Infants and Children: A Population-based Study

BACKGROUND

Acid suppression medication is associated with Clostridium difficile infection (CDI) in adults and is increasingly prescribed to children. This study evaluated the relationship between acid suppression medication and incident CDI in children.

METHODS

This was a population-based, nested case-control study. Patients were eligible if they were aged 0-17 years with 3 or more visits or 1 year or more of follow-up in the dataset. Patients were excluded if they had comorbidities that associate with CDI and might also associate with acid suppression medication. Patients with codes for CDI were matched 1:5 with control patients by age, sex, medical practice, time of entry into the dataset, and follow-up time. The primary exposure was use of acid suppression medication with proton pump inhibitors (PPIs) or histamine-2 receptor antagonists (H2RAs) within 8-90 days.

RESULTS

We identified 650 CDI cases and 3200 controls. The adjusted odds ratio (OR) for CDI and acid suppression medication was 7.66 (95% confidence interval [CI], 3.24-18.1). Acid suppression medication was associated with CDI in infants aged <1 year (OR, 5.24; 95% CI, 1.13-24.4) and children aged 1-17 years (OR, 9.33; 95% CI, 3.25-26.8). There was increased risk for CDI with PPIs compared with H2RAs and with recent compared with distant exposure.

CONCLUSIONS

Acid suppression medication associated with CDI in infants and children in the outpatient setting, with an effect based on medication timing. Increased risk for CDI should be factored into the decision to use acid suppression medication in children.

Variation in germination of Clostridium difficile clinical isolates correlates to disease severity

Over the past two decades, Clostridium difficile infections have been increasing in both number and severity throughout the world. As with other spore forming bacteria, germination is a vital step in the life cycle of this pathogen. Studies have examined differences in sporulation and toxin production among a number of C. difficile clinical isolates; however, few have examined differences in germination and the relationship between this phenotype and disease severity. Here, over 100 C. difficile isolates from the University of Michigan Health System were examined for overall germination in response to various combinations of known germinants (taurocholate) and co-germinants (glycine and histidine). Significant variation was observed among isolates under all conditions tested. Isolates representing ribotype 014-020, which was the most frequently isolated ribotype at our hospital, exhibited increased germination in the presence of taurocholate and glycine when compared to isolates representing other ribotypes. Interestingly, isolates that caused severe disease exhibited significantly lower germination in response to minimal germination conditions (taurocholate only), indicating increased control over germination in these isolates. These data provide a broad picture of C. difficile isolate germination and indicate a role for precise control of germination in disease severity.