Epidemiological investigation of Clostridioides difficile colonization in Chinese community infants

Novel target and PCR assay for identification of hypervirulent ST1 (BI/NAP1/027) Clostridioides difficile and detection of toxigenic C. Difficile

BACKGROUND AND AIMS

The incidence of Clostridioides difficile infection and the prevalence of hypervirulent ST1 (BI/NAP1/027)strain are increasing, especially in developing countries. We aimed to develop a new PCR assay for the identification of hypervirulent ST1 strains and toxigenic C. difficile in stool samples.

MATERIALS AND METHODS

We established a quadruplex TaqMan real-time PCR (pilW_4-plex PCR) assay targeting the pilW, a ST1-specific type Ⅳ minor pilin gene, and three C. difficile genes including cdtB, tcdB, and hsp. The sensitivity and specificity of the assay was tested using 403C. difficile isolates and 180 unformed stool sample. The results were compared with anaerobic culture-based conventional PCR method and MLST.

RESULTS

The pilW_4-plex PCR identified toxigenic C. difficile in 333 (82.6%, 333/403) isolates with 100% sensitivity and specificity, and in 78 (43.3%, 78/180) stool samples with the sensitivity and specificity of 94.7% and 93.3%, respectively. Hypervirulent ST1 were detected in 21 strains and nine stool samples by the pilW_4-plex PCR. The pilW_4-plex PCR assay has no cross-reaction with non-toxigenic C. difficile or other bacteria.

CONCLUSION

The pilW_4-plex PCR assay is an accurate and rapid method with high sensitivity and specificity for identification of ST1 and detection of toxigenic C. difficile in stool.

The burden of Clostridioides difficile infections in South-East Asia and the Western Pacific: A narrative review

BACKGROUND

Clostridioides difficile (formerly Clostridium difficile) is well-documented in Europe and North America to be a common cause of healthcare-associated gastrointestinal tract infections. In contrast, C difficile infection (CDI) is infrequently reported in literature from Asia, which may reflect a lack of clinician awareness. We conducted a narrative review to better understand CDI burden in Asia.

METHODS

We searched the PubMed database for English language articles related to C difficile, Asia, epidemiology, and molecular characteristics (eg, ribotype, antimicrobial resistance).

RESULTS

Fifty-eight articles that met eligibility criteria were included. C difficile prevalence ranged from 7.1% to 45.1 % of hospitalized patients with diarrhea, and toxigenic strains among all C difficile in these patients ranged from 68.2% to 91.9 % in China and from 39.0% to 60.0 % outside of China. Widespread C difficile ribotypes were RT017, RT014/020, RT012, and RT002. Recurrence in patients with CDI ranged from 3.0% to 17.2 %. Patients with CDI typically had prior antimicrobial use recently. High rates of resistance to ciprofloxacin, clindamycin, and erythromycin were frequently reported.

CONCLUSION

The regional CDI burden in Asia is still incompletely documented, seemingly due to low awareness and limited laboratory testing. Despite this apparent under recognition, the current CDI burden highlights the need for broader surveillance and for application of preventative measures against CDI in Asia.

Prevalence and molecular characterization of Clostridioides difficile infection in China over the past 5 years: a systematic review and meta-analysis

OBJECTIVES

The aim of this study was to provide an overview of the prevalence and molecular characteristics of Clostridioides difficile infection (CDI) in China in the past 5 years.

METHODS

A systematic literature review was conducted according to the preferred reporting items for systematic reviews and meta-analyses guidelines. Nine databases were searched for relevant studies published between January 2017 and February 2022. The Joanna Briggs Institute critical appraisal tool was used to assess the quality of included studies, and R software version 4.1.3 was used for data analysis. Funnel plots and Egger regression tests were also performed to assess publication bias.

RESULTS

A total of 50 studies were included in the analysis. The pooled prevalence of CDI in China was 11.4% (2696/26,852). The main circulating C. difficile strains in southern China were ST54, ST3, and ST37, consistent with the overall situation in China. However, the most prevalent genotype in northern China was ST2, which was previously underappreciated.

CONCLUSION

Based on our findings, increased awareness and management of CDI is necessary to reduce the prevalence of CDI in China.

In vitro activity of fidaxomicin against nontuberculosis mycobacteria

Introduction. Nontuberculous mycobacteria (NTM) infections are increasing worldwide and are relatively resistant to many of the first- and second-line drugs to treat tuberculosis. Macrolide antibiotics, such as clarithromycin and azithromycin, are the key drugs for treating NTM infections. Fidaxomicin is a macrolide antibiotic that is widely used in treating Clostridium difficle (C.difficile) infections, and has high in vitro activity against Mycobacterium tuberculosis especially multidrug-resistant tuberculosis (MDR-TB) and has no cross-resistance with rifampicin.Hypothesis. Fidaxomicin may have in vitro activity against NTM strains.Aim. To find that whether the macrolide antibiotic fidaxomicin has in vitro activity against NTM strains.Methodology. Fidaxomicin used in this study was firstly tested on C. difficile reference strains and has shown to be effective and workable. And then 28 rapidly growing mycobacteria (RGM), 12 slowly growing mycobacteria (SGM) reference strains and 103 NTM clinical isolates were tested by the microplate-based AlamarBlue assay (MABA) method to determine the MICs. Fidaxomicin, rifampicin and clarithromycin were tested against M. abcessus complex subspecies 14 M. abscessus and 5 M. massiliense strains for inducible resistance determination.Results. In total, 21 out of 28 RGM and 9 of 12 SGM reference strains have the MICs of fidaxomicin at or below 1 µg ml^-1. Fidaxomicin also showed low MIC values for some clinical isolates including M. abscessus complex, M. avium complex, M. fortuitum, M. kansasii and M. parascrofulaceum. Fidaxomicin also has no inducible macrolide resistance in M. abscessus complex in comparison with clarithromycin.Conclusion. Fidaxomicin has high in vitro activity against most of the NTM reference strains and some prevalent NTM clinical isolates. This promising finding warrants further investigation on the actions of fidaxomicn in vivo and as a potential antibiotic for NTM treatment.

Clostridioides difficile epidemiology in the Middle and the Far East

OBJECTIVES

Clostridioides difficile is an important pathogen of healthcare-associated gastrointestinal infections. Recently, an increased number of C. difficile infection (CDI) surveillance data has been reported from Asia. The aim of this review is to summarize the data on the prevalence, distribution and molecular epidemiology of CDI in the Middle and the Far East.

METHODS

Literature was drawn from a search of PubMed up to September 30, 2021.

RESULTS

The meta-analysis of data from 111 studies revealed the pooled CDI prevalence rate in the Middle and the Far East of 12.4% (95% CI 11.4-13.3); 48 studies used PCR for CDI laboratory diagnoses. The predominant types (RT)/sequence type (ST) differ between individual countries (24 studies, 14 countries). Frequently found RTs were 001, 002, 012, 017, 018 and 126; RT017 was predominant in the Far East. The epidemic RT027 was detected in 8 countries (22 studies), but its predominance was reported only in three studies (Israel and Iran). The contamination of vegetable and meat or meat products and/or intestinal carriage of C. difficile in food and companion animals have been reported; the C. difficile RTs/STs identified overlapped with those identified in humans.

CONCLUSIONS

A large number of studies on CDI prevalence in humans from the Middle and the Far East have been published; countries with no available data were identified. The number of studies on C. difficile from non-human sources is limited. Comparative genomic studies of isolates from different sources are needed.

The Role of Microbiota in Infant Health: From Early Life to Adulthood

From early life to adulthood, the microbiota play a crucial role in the health of the infant. The microbiota in early life are not only a key regulator of infant health but also associated with long-term health. Pregnancy to early life is the golden time for the establishment of the infant microbiota, which is affected by both environmental and genetic factors. Recently, there is an explosion of the studies on the role of microbiota in human diseases, but the application to disease or health is relatively limited because many aspects of human microbiota remain controversial, especially about the infant microbiota. Therefore, a critical and conclusive review is necessary to understand fully the relationship between the microbiota and the health of infant. In this article, we introduce in detail the role of microbiota in the infant from pregnancy to early life to long-term health. The main contents of this article include the relationship between the maternal microbiota and adverse pregnancy outcomes, the establishment of the neonatal microbiota during perinatal period and early life, the composition of the infant gut microbiota, the prediction of the microbiota for long-term health, and the future study directions of microbiota.

Prevalence of Detection of Clostridioides difficile Among Asymptomatic Children: A Systematic Review and Meta-analysis

IMPORTANCE

Detection of Clostridioides difficile has frequently been described in asymptomatic infants and children, but accurate estimates across the age spectrum are unavailable.

OBJECTIVE

To assess the prevalence of C difficile detection among asymptomatic children across the age spectrum.

DATA SOURCES

This systematic review and meta-analysis included a search of the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, CINAHL, Scopus, and Web of Science for articles published from January 1, 1990, to December 31, 2020. Search terms included Clostridium difficile, Peptoclostridium difficile, Clostridioides difficile, CDF OR CDI OR c diff OR c difficile, Clostridium infections OR cd positive diarrhea OR cd positive diarrhea OR Clostridium difficile OR Peptoclostridium difficile OR pseudomembranous colitis OR pseudomembranous enterocolitis, enterocolitis, and pseudomembranous. These were combined with the following terms: bacterial colonization and colonization OR colonized OR colonizing OR epidemiology OR prevalence OR seroprevalence.

STUDY SELECTION

Studies were screened independently by 2 authors. Studies were included if they reported testing for C difficile among asymptomatic children (ie, children without diarrhea) younger than 18 years.

DATA EXTRACTION AND SYNTHESIS

Data were extracted independently and in duplicate by 2 reviewers. Preferred Reporting Items for a Systematic Review and Meta-analysis (PRISMA) guidelines were used. Data were pooled using a random-effects model.

MAIN OUTCOMES AND MEASURES

The primary outcome was prevalence of C difficile detection among asymptomatic children. Secondary outcomes included prevalence of toxigenic vs nontoxigenic strains of C difficile and prevalence of C difficile detection stratified by geographic region, income status, testing method, and year of testing.

RESULTS

A total of 95 studies with 19 186 participants were included. Rates of detection of toxigenic or nontoxigenic C difficile were greatest among infants aged 6 to 12 months (41%; 95% CI, 32%-50%) and decreased to 12% (95% CI, 7%-18%) among children aged 5 to 18 years. The prevalence of toxigenic C difficile colonization was lower, peaking at 14% (95% CI, 8%-21%) among infants aged 6 to 12 months and decreasing to 6% (95% CI, 2%-11%) among children older than 5 years. Although prevalence differed by geographic region (ie, North and South America vs Europe: β, -0.151, P = .001; North and South America vs Western Pacific: β, 0.136, P = .007), there was no difference by testing method (ie, culture vs polymerase chain reaction: β, 0.069, P = .052; culture vs enzyme immunoassay: β, -0.178, P = .051), income class (low-middle income vs high income: β, -0.144, P = .23; upper-middle vs high income: β, -0.020, P = .64), or period (before 1990 vs 2010-2020: β, -0.125, P = .19; 1990-1999 vs 2010-2020: β, -0.037, P = .42; 2000-2009 vs 2010-2020: β, -0.006, P = .86).

CONCLUSIONS AND RELEVANCE

In this systematic review and meta-analysis, C difficile colonization rates among children were greatest at 6 to 12 months of age and decreased thereafter. These estimates may provide context for interpreting C difficile test results among young children.

Carriage of Clostridioides difficile in healthy infants in the community of Handan, China: A 1-year follow-up study

OBJECTIVE

Clostridioides difficile may colonize healthy infants and young children asymptomatically and for the long-term. C. difficile genotypes and the rate and determinants of colonization differ substantially and vary among countries and regions. A 1-year follow-up study was performed to determine the incidence, kinetics and influencing factors of C. difficile intestinal colonization.

METHODS

Twenty-nine healthy infants (14 girls and 15 boys) living at home with their parents in Handan City were followed by survey from birth to 1 year of age, specifically from October 2014 through December 2015. C. difficile isolates were typed by PCR ribotyping and analyzed for the presence of toxin genes.

RESULTS

During the follow-up study period in the first year of life, 20 of the 29 total enrolled infants acquired C. difficile. A total of 437 fecal samples were obtained, and 111 (25.4%) samples contained C. difficile, including 79 (71.2%) toxigenic strains. The toxigenic isolates comprised six PCR ribotypes, and two PCR ribotypes were identified as nontoxigenic strains.

CONCLUSION

Our study showed that C. difficile colonization increase with age during the 12-month period, and the dominant toxigenic types of C. difficile isolates in infants were those involved in long-term colonization. Feeding patterns may affect the dynamic progress of C. difficile colonization.

Molecular characteristics of Clostridium difficile in children with acute gastroenteritis from Zhejiang

Background

Clostridium difficile infection (CDI) has an increasing pediatric prevalence worldwide. However, molecular characteristics of C. difficile in Chinese children with acute gastroenteritis have not been reported.

Methods

A five-year cross-sectional study was conducted in a tertiary children’s hospital in Zhejiang. Consecutive stool specimens from outpatient children with acute gastroenteritis were cultured for C. difficile, and isolates then were analyzed for toxin genes, multi-locus sequence type and antimicrobial resistance. Diarrhea-related viruses were detected, and demographic data were collected.

Results

A total of 115 CDI cases (14.3%), and 69 co-infected cases with both viruses and toxigenic C. difficile, were found in the 804 stool samples. The 186 C. difficile isolates included 6 of toxin A-positive/toxin B-positive/binary toxin-positive (A⁺B⁺CDT⁺), 139 of A⁺B⁺CDT⁻, 3 of A⁻B⁺CDT⁺, 36 of A⁻B⁺CDT⁻ and 2 of A⁻B⁻CDT⁻. Sequence types 26 (17.7%), 35 (11.3%), 39 (12.4%), 54 (16.7%), and 152 (11.3%) were major genotypes with significant differences among different antimicrobial resistances (Fisher's exact test, P < 0.001). The A⁻B⁺ isolates had significantly higher resistance, compared to erythromycin, rifampin, moxifloxacin, and gatifloxacin, than that of the A⁺B⁺ (χ² = 7.78 to 29.26, P < 0.01). The positive CDI rate in infants (16.2%) was significantly higher than that of children over 1 year old (10.8%) (χ² = 4.39, P = 0.036).

Conclusions

CDI has been revealed as a major cause of acute gastroenteritis in children with various genotypes. The role of toxigenic C. difficile and risk factors of CDI should be emphatically considered in subsequent diarrhea surveillance in children from China.