Hospital-acquired Clostridium difficile infection in Mainland China: A seven-year (2009-2016) retrospective study in a large university hospital

Clinical characteristics of community-onset Clostridioides difficile infections at a tertiary hospital in mainland China: A fourteen-year (2010-2023) retrospective study

BACKGROUND

Clostridioides difficile infection (CDI) is an increasingly common disease in healthcare facilities and community settings. However, there are limited reports of community-onset CDI (CO-CDI) in China.

METHODS

We collected diarrheal stool samples from 3885 patients who went to outpatient department or emergency department in a tertiary hospital in China during 2010-2023, analyzed the correlation between patients' basic information and the detection rate of CDI. Besides, all stool samples from 3885 outpatients included were tested by culturing. Moreover, we randomly selected 89 patients' stools during the 14 years and isolated 126 C. difficile strains from them. The presence of toxin genes (tcdA, tcdB, cdtA, and cdtB) were confirmed by PCR. Toxigenic strains were typed using multilocus sequence typing (MLST). Susceptibility to 9 antimicrobials was evaluated using the E-test.

RESULTS

528 of 3885 patients (13.6 %) with diarrhea were finally diagnosed as CDI. The median age of patients included was 51 years (6 months-95 years), while the median of patients with CDI was older than patients with negative results [55.5 years (6 months-93 years) vs. 50 years (9 months -95 years), p < 0.001]. In winter, patients with diarrhea might be more likely to have CDI. The detection rate of CDI of patients in emergency department was much higher than those in other outpatients (20.7 % vs. 12.4 %, p < 0.001), and did differ from each outpatient departments (p < 0.05). There were 95 isolated strains detected as toxigenic C. difficile. Among these strains, 82 (86.3 %) had the tcdA and tcdB genes (A+B+) and 5 of these 82 strains were positive for the binary toxin genes (cdtA and cdtB) (A+B+CDT+). There were 15 different sequence types (STs) by multilocus sequence typing (MLST), while the most ST was ST-54 (23.2 %). ST types composition was relatively stable over the time span of this study. Some strains had high resistance to ciprofloxacin, clindamycin, and erythromycin. Twenty-three isolates (24.2 %) were multidrug-resistant.

CONCLUSIONS

Outpatients with CDI were common among patients having diarrhea during this period in our hospital. Elderly patients and patients went to emergency department may be susceptible to CDI. Based on MLST, the result revealed that the C. difficile isolates had high genetic diversity and maintained stability in this period. All isolates were susceptible to metronidazole and vancomycin, and nearly one quarter of all isolates had multidrug resistance.

[Analysis of Clostridioides difficile infection characteristics and risk factors in patients hospitalized for diarrhea in 3 university hospitals in a mid-south city of China]

OBJECTIVE

To investigate the characteristics of Clostridioides difficile infection (CDI) in patients hospitalized for diarrhea and analyze the risk factors for CDI.

METHODS

Stool samples were collected from 306 patients with diarrhea hospitalized in 3 university hospitals in a mid-south city of China from October to December, 2020. C. difficile was isolated by anaerobic culture, and qRT-PCR was used to detect the expressions of toxin A (tcdA) and B (tcdB) genes and the binary toxin genes (cdtA and cdtB). Multilocus sequence typing (MLST) was performed for the isolated strains without contaminating strains as confirmed by 16S rDNA sequencing. Etest strips were used to determine the drug resistance profiles of the isolated strains, and the risk factors of CDI in the patients were analyzed.

RESULTS

CDI was detected in 25 (8.17%) out of the 306 patients. All the patients tested positive for tcdA and tcdB but negative for the binary toxin genes. Seven noncontaminated C. difficile strains with 5 ST types were isolated, including 3 ST54 strains and one strain of ST129, ST98, ST53, and ST631 types each, all belonging to clade 1 and sensitive to metronidazole and vancomycin. Hospitalization within the past 6 months (OR= 3.675; 95% CI: 1.405-9.612), use of PPIs (OR=7.107; 95% CI: 2.575-19.613), antibiotics for ≥1 week (OR=7.306; 95% CI: 2.274-23.472), non-steroidal anti-inflammatory drugs (OR=4.754; 95% CI: 1.504-15.031) in the past month, and gastrointestinal disorders (OR=5.050; 95% CI: 1.826-13.968) were all risk factors for CDI in the patients hospitalized for diarrhea.

CONCLUSION

The CDI rate remains low in the hospitalized patients with diarrhea in the investigated hospitals, but early precaution measures are recommended when exposure to the risk factors is reported to reduce the risk of CDI in the hospitalized patients.

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.

Molecular characterization and antibiotic resistance of Clostridioides difficile in patients with inflammatory bowel disease from two hospitals in China

OBJECTIVE

Patients with inflammatory bowel disease (IBD) are susceptible to Clostridioides difficile infection (CDI), resulting in poor outcomes and recurrence; therefore, the molecular characterization of C. difficle in IBD patients in China needs further investigation.

METHODS

C. difficile strains were isolated and identified from fecal samples of adult and pediatric IBD patients. Toxigenic strains were typed using multilocus sequence typing (MLST) and whole genomic sequencing (WGS) to construct the phylogenetic tree. Susceptibility to 10 antimicrobials was evaluated using the E-test.

RESULTS

Among the 838 IBD patients, 82 toxigenic C. difficile were identified, which comprised 46 from adults and 36 children. 90.2% (74/82) of the isolates were positive for both toxin A and toxin B genes (A+B+), while the remaining 9.8% were negative for toxin A gene, but positive for toxin B gene (A-B+). These toxigenic strains were susceptible to metronidazole and vancomycin, but highly resistant to clindamycin, erythromycin, and fluoroquinolones. All moxifloxacin-resistant isolates had mutations resulting in an amino acid substitution in gryA (T82I). The dominant types were ST-35 (20.7%), ST-2 (17.1%), ST-54 (13.4%), and ST-3 (13.4%) in all patients.

CONCLUSION

The incidence and molecular epidemiology of C. difficile infection in adult IBD patients resembled CDI in the general inpatient population. A higher antibiotic resistance rate was identified among the C. difficile isolates obtained from pediatric IBD patients than adult patients, and few STs accounted for most multidrug-resistant strains. However, the molecular genetic features of the same ST-type between these two groups remains highly correlated.

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.

European Society of Clinical Microbiology and Infectious Diseases: 2021 update on the treatment guidance document for Clostridioides difficile infection in adults

SCOPE

In 2009, the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) published the first treatment guidance document for Clostridioides difficile infection (CDI). This document was updated in 2014. The growing literature on CDI antimicrobial treatment and novel treatment approaches, such as faecal microbiota transplantation (FMT) and toxin-binding monoclonal antibodies, prompted the ESCMID study group on C. difficile (ESGCD) to update the 2014 treatment guidance document for CDI in adults.

METHODS AND QUESTIONS

Key questions on CDI treatment were formulated by the guideline committee and included: What is the best treatment for initial, severe, severe-complicated, refractory, recurrent and multiple recurrent CDI? What is the best treatment when no oral therapy is possible? Can prognostic factors identify patients at risk for severe and recurrent CDI and is there a place for CDI prophylaxis? Outcome measures for treatment strategy were: clinical cure, recurrence and sustained cure. For studies on surgical interventions and severe-complicated CDI the outcome was mortality. Appraisal of available literature and drafting of recommendations was performed by the guideline drafting group. The total body of evidence for the recommendations on CDI treatment consists of the literature described in the previous guidelines, supplemented with a systematic literature search on randomized clinical trials and observational studies from 2012 and onwards. The Grades of Recommendation Assessment, Development and Evaluation (GRADE) system was used to grade the strength of our recommendations and the quality of the evidence. The guideline committee was invited to comment on the recommendations. The guideline draft was sent to external experts and a patients' representative for review. Full ESCMID endorsement was obtained after a public consultation procedure.

RECOMMENDATIONS

Important changes compared with previous guideline include but are not limited to: metronidazole is no longer recommended for treatment of CDI when fidaxomicin or vancomycin are available, fidaxomicin is the preferred agent for treatment of initial CDI and the first recurrence of CDI when available and feasible, FMT or bezlotoxumab in addition to standard of care antibiotics (SoC) are preferred for treatment of a second or further recurrence of CDI, bezlotoxumab in addition to SoC is recommended for the first recurrence of CDI when fidaxomicin was used to manage the initial CDI episode, and bezlotoxumab is considered as an ancillary treatment to vancomycin for a CDI episode with high risk of recurrence when fidaxomicin is not available. Contrary to the previous guideline, in the current guideline emphasis is placed on risk for recurrence as a factor that determines treatment strategy for the individual patient, rather than the disease severity.

Prognostic factors for severe and recurrent Clostridioides difficile infection: a systematic review

OBJECTIVES

Clostridioides difficile infection (CDI), its subsequent recurrences (rCDIs), and severe CDI (sCDI) provide a significant burden for both patients and the healthcare system. Identifying patients diagnosed with initial CDI who are at increased risk of developing sCDI/rCDI could lead to more cost-effective therapeutic choices. In this systematic review we aimed to identify clinical prognostic factors associated with an increased risk of developing sCDI or rCDI.

METHODS

PubMed, Embase, Emcare, Web of Science and COCHRANE Library databases were searched from database inception through March, 2021. The study eligibility criteria were cohort and case-control studies. Participants were patients ≥18 years old diagnosed with CDI, in which clinical or laboratory factors were analysed to predict sCDI/rCDI. Risk of bias was assessed by using the Quality in Prognostic Research (QUIPS) tool and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) tool modified for prognostic studies. Study selection was performed by two independent reviewers. Overview tables of prognostic factors were constructed to assess the number of studies and the respective effect direction and statistical significance of an association.

RESULTS

136 studies were included for final analysis. Greater age and the presence of multiple comorbidities were prognostic factors for sCDI. Identified risk factors for rCDI were greater age, healthcare-associated CDI, prior hospitalization, proton pump inhibitors (PPIs) started during or after CDI diagnosis, and previous rCDI.

CONCLUSIONS

Prognostic factors for sCDI and rCDI could aid clinicians to make treatment decisions based on risk stratification. We suggest that future studies use standardized definitions for sCDI/rCDI and systematically collect and report the risk factors assessed in this review, to allow for meaningful meta-analysis of risk factors using data of high-quality trials.

Healthcare providers' perception of faecal microbiota transplantation with clostridium difficile infection and inflammatory bowel disease: a quantitative systematic review

BACKGROUND

Clostridioides difficile infection (CDI) and inflammatory bowel disease (IBD) are global gastroenterological diseases that cause considerable burden on human health, healthcare systems, and society. Faecal microbiota transplantation (FMT) is an effective treatment for recurrent Clostridioides Difficile Infection (rCDI) and a promising therapy for IBD. However, indication for FMT in IBD is still unofficial. Consequently, the National Institute for Health and Care Excellence (NICE) is seeking healthcare providers' advice on whether to update FMT guidelines.

METHODS

A systematic review methodology was adopted for this study. Five databases (CINAHL, MEDLINE, Cochrane Library, Scopus, Web of Science) and grey literature were systematically searched for English language literature to 14 May 2021. The quality of the included studies was then appraised using the Institute for Public Health Sciences cross-sectional studies tool, after which the findings of the studies were narratively synthesised.

RESULTS

Thirteen cross-sectional studies with 4110 validated questionnaire responses were included. Narrative synthesis found that 39.43% of respondents were familiar with FMT (N = 3746, 95%CI = 37.87%-41%), 58.81% of respondents would recommend FMT to their patients (N = 1141, 95%CI = 55.95%-61.67%), 66.67% of respondents considered lack of clinical evidence was the greatest concern regarding FMT (N = 1941, 95%CI = 64.57%-68.77%), and 40.43% respondents would not implement FMT due to concerns about infection transmission (N = 1128, 95%CI = 37.57%-43.29%).

CONCLUSION

Healthcare providers' knowledge of FMT is relatively low and education is an effective strategy to improve it. As knowledge of FMT increases, willingness to recommend it also increases. Strengthening FMT clinical efficacy and reducing infection can enhance its public acceptance, application and popularity. However, further research is required to explore the donor screening procedure.

Hypoalbuminemia as Surrogate and Culprit of Infections

Hypoalbuminemia is associated with the acquisition and severity of infectious diseases, and intact innate and adaptive immune responses depend on albumin. Albumin oxidation and breakdown affect interactions with bioactive lipid mediators that play important roles in antimicrobial defense and repair. There is bio-mechanistic plausibility for a causal link between hypoalbuminemia and increased risks of primary and secondary infections. Serum albumin levels have prognostic value for complications in viral, bacterial and fungal infections, and for infectious complications of non-infective chronic conditions. Hypoalbuminemia predicts the development of healthcare-associated infections, particularly with Clostridium difficile. In coronavirus disease 2019, hypoalbuminemia correlates with viral load and degree of acute lung injury and organ dysfunction. Non-oncotic properties of albumin affect the pharmacokinetics and pharmacodynamics of antimicrobials. Low serum albumin is associated with inadequate antimicrobial treatment. Infusion of human albumin solution (HAS) supplements endogenous albumin in patients with cirrhosis of the liver and effectively supported antimicrobial therapy in randomized controlled trials (RCTs). Evidence of the beneficial effects of HAS on infections in hypoalbuminemic patients without cirrhosis is largely observational. Prospective RCTs are underway and, if hypotheses are confirmed, could lead to changes in clinical practice for the management of hypoalbuminemic patients with infections or at risk of infectious complications.

Gold Nanoclusters as an Antibacterial Alternative Against Clostridium difficile

Background

Clostridium difficile infection (CDI) has become one of the most important factors threatening human health, and about 20-30% antibiotic-related diarrhea cases and almost all pseudomembranous enteritis cases are related to CDI. The high recurrence of Clostridium difficile (C. difficile) and the emergence of drug resistance make clinical treatment of CDI difficult. Therefore, there is an urgent need to develop a non-antibiotic-alternative therapy against CDI. Gold nanoclusters (AuNCs) can better interact with bacteria due to its ultrasmall size. The aim of the present study was to explore whether AuNCs could be used as an antibacterial agent to kill C. difficile.

Methods

AuNCs and C. difficile were co-cultivated in an anaerobic atmosphere to evaluate the bactericidal effect of AuNCs. The bacterial growth rate was estimated by using two concentrations of AuNCs (50 and 100 μM). The damage of AuNCs to C. difficile is detected by SYTOX Green staining methods and SEM image analysis. The mechanism of AuNCs on C. difficile was explored by reactive oxygen species (ROS) detection. The toxic effect of AuNCs on human cells was evaluated by MTT method.

Results

AuNCs (100 μM) killed C. difficile drastically. AuNCs increased the release of ROS by about 5 fold and destroyed the membrane integrity of C. difficile cells without causing significant toxic effect on human cells.

Conclusion

AuNCs showed great potential as an alternative to traditional antibiotics in killing C. difficile and may prove to be an alternative to treat CDI.

Eosinophilic Colitis and Clostridioides difficile Sepsis With Rapid Remission After Antimicrobial Treatment; A Rare Coincidence and Its Pathogenic Implications

Eosinophilic colitis is a rare inflammatory disorder of the digestive tract with chronic evolution and unknown pathophysiological mechanisms. The article describes the case of a 64-year old woman with a history of asthma and hypereosinophilia, who presented to a surgical department for persistent abdominal pain in the past 4 months, weight loss and malabsorption. She was diagnosed with eosinophilic colitis based on the colonoscopic result indicating extensive eosinophilic infiltration of the colonic mucosa correlated with the laboratory data and abdominal CT scan results. Following the colonoscopy, the patient developed fever, hypotension and diarrhea and was transferred to an Infectious Diseases Department with a presumptive diagnosis of abdominal sepsis. Treatment with ertapenem was immediately started. Metronidazole was also added due to a PCR positive stool test for Clostridioides difficile toxins encoding-genes. The patient displayed a rapid remission of the fever and of the intestinal complaints following antibiotic therapy and was discharged after 14 days. During a 3 months follow-up, the patient remained asymptomatic with normal values of laboratory parameters except for a persistent hypereosinophilia. The case outlines two distinguishing features: a histopathologic diagnosis of eosinophilic colitis, a rare diagnosis of a patient with chronic abdominal pain and an unexpected and rapid remission of the eosinophilic colitis following the antibiotic treatment and the restoration of the intestinal eubiosis.

Characteristics of Clostridium difficile isolates and the burden of hospital-acquired Clostridium difficile infection in a tertiary teaching hospital in Chongqing, Southwest China

BACKGROUND

Clostridium difficile infection (CDI), especially hospital-acquired Clostridium difficile infection (HA-CDI), continues to be a public health problem and has aroused great concern worldwide for years. This study aimed to elucidate the clinical and epidemiological features of HA-CDI and the characteristics of C.difficile isolates in Chongqing, Southwest China.

METHODS

A case-control study was performed to identify the clinical incidence and risk factors of HA-CDI. C. difficile isolates were characterised by polymerase chain reaction (PCR) ribotyping, multilocus sequence typing (MLST), toxin gene detection and antimicrobial susceptibility testing.

RESULTS

Of the 175 suspicious patients, a total of 122 patients with antibiotic-associated diarrhea (AAD) were included in the study; among them, 38 had HA-CDI. The incidence of AAD and HA-CDI was 0.58 and 0.18 per 1000 patient admissions, respectively. Chronic renal disease and cephalosporin use were independent risk factors for HA-CDI. Fifty-five strains were assigned into 16 sequence types (STs) and 15 ribotypes (RTs). ST2/RT449 (8, 14.5%) was the predominant genotype. Of the 38 toxigenic isolates, A + B + CDT- isolates accounted for most (34, 89.5%) and 1 A + B + CDT+ isolate emerged. No isolate was resistant to vancomycin, metronidazole or tigecycline, with A-B-CDT- being more resistant than A + B + CDT-.

CONCLUSIONS

Different genotypes of C. difficile strains were witnessed in Chongqing, which hinted at the necessary surveillance of HA-CDI. Adequate awareness of patients at high risk of HA-CDI acquisition is advocated and cautious adoption of cephalosporins should be highlighted.

Molecular Epidemiology and Risk Factors of Clostridium difficile ST81 Infection in a Teaching Hospital in Eastern China

BACKGROUND

The prevalence of Clostridium difficile causes an increased morbidity and mortality of inpatients, especially in Europe and North America, while data on C. difficile infection (CDI) are limited in China.

METHODS

From September 2014 to August 2019, 562 C. difficile isolates were collected from patients and screened for toxin genes. Multilocus sequence typing (MLST) and antimicrobial susceptibility tests by E-test and agar dilution method were performed. A case group composed of patients infected with sequence type (ST) 81 C. difficile was compared to the non-ST81 infection group and non CDI diarrhea patients for risk factor and outcome analyses.

RESULTS

The incidence of inpatients with CDI was 7.06 cases per 10,000 patient-days. Of the 562 C. difficile isolates, ST81(22.78%) was the predominant clone over this period, followed by ST54 (11.21%), ST3 (9.61%), and ST2 (8.72%). Toxin genotype tcdA+tcdB+cdt- accounted for 50.18% of all strains, while 29.54% were tcdA-tcdB+cdt- genotypes. Overall, no isolate was resistant to vancomycin, teicoplanin or daptomycin, and resistance rates to meropenem gradually decreased during these years. Although several metronidazole-resistant strains were isolated in this study, the MIC values decreased during this period. Resistance rates to moxifloxacin and clindamycin remained higher than those to the other antibiotics. Among CDI inpatients, longer hospitalization, usage of prednisolone, suffering from chronic kidney disease or connective tissue diseases and admission to emergency ward 2 or emergency ICU were significant risk factors for ST81 clone infection. All-cause mortality of these CDI patients was 4.92%(n=18), while the recurrent cases accounted for 5.74%(n=21). The 60-day mortality of ST81-CDI was significantly higher than non-ST81 infected group, while ST81 also accounted for most of the recurrent CDI cases.

CONCLUSION

This study revealed the molecular epidemiology and risk factors for the dominant C. difficile ST81 genotype infection in eastern China. Continuous and stringent surveillance on the emerging ST81 genotype needs to be initiated.

Non-antibiotic therapy for Clostridioides difficile infection: a review

Clostridioides difficile infection (CDI) is a common infectious disease that is mainly caused by antibiotics. Antibiotic therapy is still the dominant treatment for CDI, although it is accompanied by side effects. Probiotics, fecal microbiota transplantation (FMT), engineered microorganisms, bacteriophages, diet, natural active substances, nanoparticles and compounds are examples of emerging non-antibiotic therapies that have received a great amount of attention. In this review, we collected data about different non-antibiotic therapies for CDI and provided a comprehensive analysis and detailed comparison of these therapies. The mechanism of action, therapeutic efficacy, and the strengths and weaknesses of these non-antibiotic therapies have been investigated to provide a basis for the reasonable alternative of non-antibiotic therapies for CDI. In summary, probiotics and FMT are currently the best choice for non-antibiotic therapy for CDI.

Antibacterial Activity of Bifidobacterium breve Against Clostridioides difficile

Bifidobacterium breve (YH68) is widely used in the fields of food fermentation and biomedicine. In this study, we explored the antibacterial activity of the cell free culture supernatant (CFCS) of YH68 against Clostridioides difficile ATCC 9689 (CD) by measuring multiple indexes, including the growth, spores production, toxin A/B production, and the expression levels of the tcdA and tcdB genes of CD. In addition, we examined the changes in major cellular functional groups, structures, permeability, integrity, and the proton motive force (PMF) of the cytoplasmic membrane. The results showed that double-dilution ratio of YH68-CFCS (3 × 10⁹ CFU/mL) was the MIC value. The cell density, spores production, and the toxin production of CD treated with YH68-CFCS were lower than that of the control (p < 0.05). In addition, the gene expression levels of tcdA and tcdB in CD treated with YH68-CFCS were significant downregulated (p < 0.05). Marked differences were observed in the cell membrane and cell wall by a FT-IR spectroscopy and SEM. Analysis of the cell membrane permeability and integrity of the CD cells revealed that YH68-CFCS induced the leakage of a large amount of intracellular K⁺, inorganic phosphate, ATP, nucleic acids and proteinaceous substances. Furthermore, PMF analysis indicated that there was a significant change in Δψ and ΔpH. These findings demonstrated that the antibacterial activity of YH68-CFCS against CD involved the inhibition of growth, spore production, toxin production, and virulence genes expression; a consumption of PMF in the cytoplasmic membrane, the formation of pore in the cell membrane, together with the enhanced cell membrane permeability; and, eventually, cell completely disintegration.

Whole genome analysis reveals new insights into the molecular characteristics of Clostridioides difficile NAP1/BI/027/ST1 clinical isolates in the People's Republic of China

Background: The epidemic new strain NAP1/BI/027/ST-1 of Clostridioides difficile (C. difficile) causes more severe coliti and a higher mortality rate than historical strains. However, C. difficile NAP1/BI/027/ST-1 (C. difficile RT027) infections have been rarely reported in Asia, particularly in China.

Purpose: The objective of this study was to strengthen the understanding of the molecular characterizations of C. difficile RT027 in China.

Patients and methods: Two C. difficile NAP1/BI/027/ST-1 were detected from two patients, and no additional isolates were found. Whole genome sequencing (WGS) was used to characterize two C. difficile RT027 isolates and control strain CD6 (from Hong Kong), and comparative genomic analysis was performed to compare genomic differences between seven isolates from Mainland China, CD6, and 10 isolates from North America and Europe.

Results: The comparative genomic analysis revealed that isolates obtained from Mainlan China were outside of the two epidemic lineages, FQR1 and FQR2, and might have decreased virulence and transmissibility for outbreak. Furthermore, unique SNP mutations were detected in isolates obtained from Mainland China, which may affect the biological function of C. difficile.

Conclusion: We speculate that C. difficile RT027 isolates in Mainland China may have different features, compared to those in North America and Europe.

Effect of Bifidobacterium breve in Combination With Different Antibiotics on Clostridium difficile

While combinations of probiotics with antibiotics have exhibited beneficial and adverse effects in the treatment of Clostridium difficile infection (CDI), no substantive explanation has been provided for these effects. In this study, C. difficile ATCC 9689 (CD) was treated with Bifidobacterium breve (YH68) in combination with five different antibiotics to explore the effects of the different combinations on C. difficile. Cell-free culture supernatant (CFCS) of YH68 was combined with metronidazole (MTR), vancomycin (VAN), clindamycin (CLI), ceftazidime (CAZ) or ampicillin (AMP) to treat CD. The plate counting method was used to determine the growth and spore production of CD, and cell damage was assessed by the measurement of extracellular ATP levels with a luminescence-based kit. The production of toxin A/B was measured with an ELISA kit. The gene expression levels of tcdA and tcdB in CD were evaluated by real-time qPCR. The CFCS of YH68 (3 × 109 CFU/mL) at 0.25 times the minimal inhibitory concentration (MIC) (0.25YH68) in combination with the five antibiotics exerted stronger inhibitory effects on the growth and spore production of CD than the same antibiotics in the absence of 0.25YH68, except 0.25YH68&MTR&, 0.25YH68&MTR&CAZ, and 0.25YH68&VAN&CLI. However, treatment with 0.25YH68&VAN, 0.25YH68&, 0.25YH68&MTR&CAZ, 0.25YH68&VAN&CAZ, 0.25YH68&VAN&, and 0.25YH68&CAZ& resulted in increased cell damage. In addition, the different combinations, except 0.25YH68&CLI, 0.25YH68&MTR& and 0.25YH68&VAN&CLI, dramatically reduced the production of toxin A/B in comparison with the effects of the same antibiotics in the absence of 0.25YH68. The gene expression levels of tcdA and tcdB in CD were lowered upon treatment with 0.25YH68 in combination with MTR, CLI, CAZ, MTR&CAZ, MTR&, CLI&CAZ, and CLI&, whereas the levels were enhanced by 0.25YH68 in combination with VAN, AMP, MTR&CLI, VAN&CLI, VAN&, and CAZ&. In summary, YH68 in combination with specific antibiotics could enhance the inhibitory effects of antibiotics against CD. In addition, the antagonistic effects between some antibiotics could be weakened by YH68.

Protective Effect of Pediococcus pentosaceus LI05 Against Clostridium difficile Infection in a Mouse Model

Clostridium difficile infection (CDI) is a major cause of infectious diarrhea among hospitalized patients. Probiotics could be instrumental in restoring the intestinal dysbiosis caused by CDI. Here, we examined the protective effect of Pediococcus pentosaceus LI05 in a mouse CDI model. C57BL/6 mice were administrated P. pentosaceus LI05 (LI05 group) or sterile anaerobic PBS (CDI group) everyday for 14 days. Mice were exposed to antibiotics cocktail for 5 days; then challenged with C. difficile strain VPI10463. Mice were monitored daily for survival and weight loss. Colonic tissue and serum samples were assessed for intestinal histopathology, intestinal barrier function and systemic inflammation. The oral administration of P. pentosaceus LI05 improved the survival rate and alleviated the histopathological impact of C. difficile. Compared to the CDI group, the levels of inflammatory mediators in the colon as well as inflammatory cytokines and chemokines in serum were substantially attenuated in the LI05 group. P. pentosaceus LI05 alleviated the CDI-induced of disruption of ZO-1, occludin and claudin-1. Additionally, fecal microbiome analysis showed an enrichment in the abundance of the Porphyromonadaceae and Rikenellaceae, while, the relative abundance of Enterobacteriaceae were decreased. Our results demonstrated that the preventive effect of P. pentosaceus LI05 against CDI was mediated via improving tight junction proteins and down-regulating the inflammatory response. Therefore, P. pentosaceus LI05 could be a promising probiotic in CDI.