The First Two Clostridium difficile Ribotype 027/ST1 Isolates Identified in Beijing, China-an Emerging Problem or a Neglected Threat?

Prevalence of toxigenic Clostridium difficile in hospitalized patients in the southwestern province of Saudi Arabia: Confirmation using the GeneXpert analysis

Clostridium difficile (Clostridioides difficile) is a leading cause of nosocomial infections in hospitalized patients worldwide. Stool samples were collected from 112 inpatients admitted to different hospitals and were screened for C. difficile GDH + toxin A + B by immunoassay, and all positive samples by immunoassay were processed for molecular detection of C. difficile using the GeneXpert assay. C. difficile strains were detected in 12 (10.71%) out of 112 stool samples using the GDH + toxin A + B immunoassay method and toxigenic C. difficile was confirmed in 5 stool samples using the GeneXpert molecular assay. C. difficile strains were also detected in 7 (8.97%) out of 78 stool samples from intensive care unit patients, 3 (25%) out of 12 stool samples from internal medicine ward patients, 1 (11.11%) out of 9 stool samples from surgery ward patients, and 1 (10%) out of 10 stool samples from isolation ward patients using the GDH + toxin A + B immunoassay method and the toxigenic C. difficile strain was confirmed in 1, 2, 1, and 1 stool samples, respectively, using the GeneXpert molecular assay. Toxigenic C. difficile was confirmed in patients at 4 (51.14%) out of 7 hospitals. In the present study, we also analyzed the clinical information of patients with C. difficile-positive stool samples who were receiving one or more antibiotics during hospitalization. The binary toxin gene (cdt), the tcdC gene, and the C. difficile strain polymerase chain reaction (PCR) ribotype 027 were not detected using the GeneXpert molecular assay among 12 C. difficile-positive samples by immunoassay. This study should aid in the prevention of unnecessary empiric therapy and increase the understanding of the toxigenic C. difficile burden on the healthcare system in the southwestern province of Saudi Arabia.

Toxin genotypes, antibiotic resistance and their correlations in Clostridioides difficile isolated from hospitals in Xi'an, China

BACKGROUND

Clostridioides difficile is the main pathogen of antimicrobial-associated diarrhoea and health care facility-associated infectious diarrhoea. This study aimed to investigate the prevalence, toxin genotypes, and antibiotic resistance of C. difficile among hospitalized patients in Xi'an, China.

RESULTS

We isolated and cultured 156 strains of C. difficile, representing 12.67% of the 1231 inpatient stool samples collected. Among the isolates, tcdA + B + strains were predominant, accounting for 78.2% (122/156), followed by 27 tcdA-B + strains (27/156, 17.3%) and 6 binary toxin gene-positive strains. The positive rates of three regulatory genes, tcdC, tcdR, and tcdE, were 89.1% (139/156), 96.8% (151/156), and 100%, respectively. All isolates were sensitive to metronidazole, and the resistance rates to clindamycin and cephalosporins were also high. Six strains were found to be resistant to vancomycin.

CONCLUSION

Currently, the prevalence rate of C. difficile infection (CDI) in Xi'an is 12.67% (156/1231), with the major toxin genotype of the isolates being tcdA + tcdB + cdtA-/B-. Metronidazole and vancomycin were still effective drugs for the treatment of CDI, but we should pay attention to antibiotic management and epidemiological surveillance of CDI.

Molecular epidemiology, antimicrobial susceptibility, and toxin production of clinical Clostridioides difficile isolates from a teaching hospital in Northern China

To grasp the epidemiological trend and drug resistance mechanisms of Clostridioides difficile (C. diff) in Beijing, 302 C. diff isolates were obtained from patients with diarrhea. The sequence types (STs) from mainstream strains were all susceptible to metronidazole, vancomycin, piperacillin/tazobactam, meropenem, and tigecycline but almost resistant to ciprofloxacin and clindamycin. The missense mutation of GyrA/GyrB and RpoB resulted in fluoroquinolone and rifamycin resistance, respectively. Toxigenic strains from clade IV were likely to be missed due to the deficiency of tcdA gene. Four tcdC genotypes were first detected in strains from clade III and IV. The truncating mutation of TcdC disabled its function working as a toxin suppressor. In conclusion, the molecular epidemiology of C. diff in Beijing is different from other regions of China. The antimicrobial resistance patterns and toxin-producing abilities of strains with different STs varied greatly, which suggests that continuous surveillance and control are meaningful and urgent.

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.

Antibiotic Resistances and Molecular Characteristics of Clostridioides difficile in ICUs in a Teaching Hospital From Central South China

Clostridioides (C.) difficile is a major healthcare-associated pathogen inducing infectious diarrhea. Approximately 25–33% of patients with antibiotic-associated diarrhea (AAD) and 90% of patients with pseudomembranous enteritis are caused by C. difficile infection (CDI). Stool samples were collected from hospitalized adults with presumptive AAD in four nonneonatal intensive care units (ICUs). Diagnosis of CDI was based on both clinical symptoms and laboratory results. The stool specimens were transferred onto CDIF (C. difficile agar), and C. difficile was finally confirmed by the latex agglutination test. Toxin-producing genes tcdA (A), tcdB (B), and cdt (CDT) were detected by PCR, and all isolates were performed multilocus sequence typing analysis. The antibiotic susceptibility of C. difficile isolates was assessed by the agar dilution method. A total of 184 C. difficile were isolated from 857 specimens in our study, the isolation rate of C. difficile was 21.5% (184/857). The 184 C. difficile were isolated from 179 patients, among these 115 patients were toxin-positive, giving the incidence of CDI being 58.0/10,000 patient days in the four ICUs. Among these 115 toxin-positive C. difficile isolates, 100 (87.0%) isolates produced two toxins (A+B+CDT-), three (2.6%) isolates were A+B+ with binary toxin-producing (A+B+CDT+), and 12 (10.4%) isolates only produced one toxin (A-B+CDT-). A total of 27 sequencing types (STs) were obtained. The most prevalent was ST3 (34 isolates), followed by ST39 (27 isolates), ST54 (19 isolates), ST26 (16 isolates), ST35 (15 isolates), and ST2 (13 isolates). All the ST26 isolates were nontoxigenic. Meanwhile, five STs were newly discovered. Although multidrug resistance was present in ≥50% of these C. difficile isolates, all of them were susceptible to tigecycline, fidaxomicin, metronidazole, and vancomycin. In conclusion, C. difficile isolates producing two toxins (A+B+CDT-) were dominant in our hospital. The most prevalent was ST3, and all ST26 isolates were NTCD. Although multidrug resistance was present in ≥50% of the C. difficile isolates, metronidazole, tigecycline, fidaxomicin, and vancomycin were still effective treatments for CDI in our hospital.

Community-acquired fulminant Clostridioides (Clostridium) difficile infection by ribotype 027 isolate in Japan: a case report

BACKGROUND

Clostridioides (Clostridium) difficile infection (CDI) has become an increasingly significant disease not only as healthcare-associated infection, but also as community-acquired (CA) infection worldwide. CDI caused by the NAP1/BI/027 strain is reported to be more severe, difficult to cure, and frequently associated with recurrences in North America and Europe.

CASE PRESENTATION

A 68-year-old woman was referred to our hospital for continuous lower abdominal pain 4 weeks after eradication therapy against Helicobacter pylori. While she was treated with fasting on the suspicion of ischemic colitis, she experienced septic shock. Emergent subtotal proctocolectomy revealed fulminant pseudomembranous C. difficile colitis. The C. difficile isolate recovered from the patient was identified as ribotype 027, which has been reported to be uncommon in Japan.

CONCLUSION

We report a rare case of CA fulminant pseudomembranous colitis caused by ribotype 027 C. difficile after H. pylori eradication therapy.

Molecular characterization of Clostridioides difficile ribotype 027 in a major Chinese hospital

BACKGROUND

The rapid spread of C. difficile 027 has become one of the leading threats of healthcare-associated infections wordwild. However, C. difficile 027 infections have rarely been reported in China. The objective of this study was to strengthen the understanding of the molecular characterizations of C. difficile 027 in China.

METHODS

In this study, stool specimens from 176 suspected CDI cases were collected from 1 Jan 2018 to 30 Jun 2019. These specimens were measured by GeneXpert test and C.difficile colonies were identified and analyzed.

RESULTS

There were five samples positive for tcdA, tcdB, binary toxin genes and had deletions in tcdC gene. These five Clostridioides difficile isolates belonged to ST1 and confirmed as Clostridioides difficile 027 strains by PCR ribotyping. Through using whole genome sequencing, , we found that these five strains were closely clustered into the same predominant evolutionary branch and were highly similar to C. difficile 027 strain R20291. Antimicrobial susceptibility testing result showed they were highly resistant to fluoroquinolones.

CONCLUSIONS

In Our study, five C. difficile 027 isolates were identified and characterized using MLST, PCR ribotyping and whole genome sequencing. We proposed that C. difficile 027 infections are probably neglected in China. Further epidemiological studies across the country together with the introduction of routine diagnostic testing and multi-center or national level surveillance are needed to ascertain the size of this potentially significant problem.

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.

The tcdA-negative and tcdB-positive Clostridium difficile ST81 clone exhibits a high level of resistance to fluoroquinolones: a multi-centre study in Beijing, China

Clostridium difficile infection (CDI) is the leading cause of antibiotic-associated diarrhoea worldwide. In order to gain a better understanding about the molecular epidemiology of C. difficile in Beijing, China, molecular typing, antimicrobial susceptibility testing and drug resistance gene sequencing were performed on 174 strains of C. difficile collected from four large tertiary hospitals in Beijing. In total, 31 sequence types (STs) were identified among the 174 strains. ST81 was found to be the most prevalent (26.4%, 46/174), followed by ST2 (16.7%, 29/174) and ST54 (9.8%, 17/174). All isolates were susceptible to metronidazole and vancomycin. The test strains displayed resistance rates of 97.1%, 44.3% and 44.3% for ciprofloxacin, levofloxacin and moxifloxacin, respectively. ST81 isolates displayed a drug resistance rate of 97.8% for levofloxacin and moxifloxacin, which was significantly higher than ST2 (0%), ST54 (17.6%) and ST42 (0%) isolates (P<0.05). An amino acid mutation (T82I) was identified in GyrA, and the total mutation rate of the C. difficile strains was 40.8% (71/174). The mutation rate of ST81 isolates was 95.7% (44/46). Three amino acid mutations (D426N, S366A and D426V) were identified in GyrB, and the total mutation rate of GyrB was 39.1%. A double-site mutation in GyrB (S366A+D426V) was identified in all ST81 (n=46) isolates. In conclusion, the C. difficile ST81 clone showed a high level of resistance to fluoroquinolones in Beijing, highlighting the need for nationwide surveillance of CDI.

Prevalence, toxin gene profile, genotypes and antibiotic susceptibility of Clostridium difficile in a tertiary care hospital in Taif, Saudi Arabia

Purpose

Clostridium difficile (C. difficile) is an important causative agent of nosocomial diarrhoea and has become a major worldwide public health concern. The current study was conducted to determine the prevalence of C. difficile infection (CDI) amongst patients with nosocomial diarrhoea in a large tertiary care hospital in Taif, Saudi Arabia, and to define molecular characteristics and antimicrobial sensitivity profiles of C. difficile strains isolated from those patients.

Materials and Methods

Stool specimens were collected from 456 patients and were cultured for C. difficile isolation. The isolates were subjected to multiplex polymerase chain reaction (PCR) for detecting genes encoding the toxins (toxin A, toxin B and binary toxin [CDT]), genotyping by PCR ribotyping method and antimicrobial sensitivity testing using E test strips.

Results

Seventy-four C. difficile strains were recovered, of which 44 (59.5%) were A+B+CDT-, 14 (18.9%) were A-B+CDT-, 4 (5.4%) were A+B+CDT+ and 12 (16.2%) were A-B-CDT-. Toxigenic strains, and hence CDI, were detected in 13.6% of the patients (62/456). Fourteen different ribotypes were distinguished amongst bacterial isolates, of which ribotypes 002, 001, 017, 014 and 020 were the most prevalent (20.3%, 18.9%, 18.9%, 9.5% and 8.1%, respectively). Four isolates (5.4%) belonged to ribotype 027. All bacterial isolates showed sensitivity to metronidazole, vancomycin and piperacillin-tazobactam. The isolates exhibited resistance to linezolid (2.7%), chloramphenicol (5.4%), rifampicin (13.5%), tetracycline (21.6%), moxifloxacin (48.6%), clindamycin (54%) and imipenem (83.8%). Multiple drug resistance was observed in 56.8% of the isolates.

Conclusion

Further larger studies are required for an accurate understanding of CDI epidemiology in Saudi Arabia.

Comparative Study of Clostridium difficile Clinical Detection Methods in Patients with Diarrhoea

Objectives

The aim of this study was to evaluate the clinical application of three methods for detecting Clostridium difficile in fecal samples.

Methods

One hundred and fifty fecal specimens were collected and tested for C. difficile using three methods: (1) the toxigenic culture (TC); (2) the VIDAS enzyme immunoassay (EIA): the VIDAS glutamate dehydrogenase (GDH) assay and toxin A/B assay were used to detect GDH antigen and A/B toxin; and (3) the GeneXpert PCR assay. The toxigenic culture was used as a reference to evaluate the performance of the VIDAS EIA and the GeneXpert PCR assay.

Results

Of 150 specimens, 26 carried both A and B toxin genes, and none of the samples were positive for the binary toxin gene. Toxin-producing C. difficile using three methods: (1) the toxigenic culture (TC); (2) the VIDAS enzyme immunoassay (EIA): the VIDAS glutamate dehydrogenase (GDH) assay and toxin A/B assay were used to detect GDH antigen and A/B toxin; and (3) the GeneXpert PCR assay. The toxigenic culture was used as a reference to evaluate the performance of the VIDAS EIA and the GeneXpert PCR assay. C. difficile using three methods: (1) the toxigenic culture (TC); (2) the VIDAS enzyme immunoassay (EIA): the VIDAS glutamate dehydrogenase (GDH) assay and toxin A/B assay were used to detect GDH antigen and A/B toxin; and (3) the GeneXpert PCR assay. The toxigenic culture was used as a reference to evaluate the performance of the VIDAS EIA and the GeneXpert PCR assay.

Conclusion

The VIDAS GDH assay is useful for initial screening of C. difficile using three methods: (1) the toxigenic culture (TC); (2) the VIDAS enzyme immunoassay (EIA): the VIDAS glutamate dehydrogenase (GDH) assay and toxin A/B assay were used to detect GDH antigen and A/B toxin; and (3) the GeneXpert PCR assay. The toxigenic culture was used as a reference to evaluate the performance of the VIDAS EIA and the GeneXpert PCR assay.

Antibiotic resistance of clinical isolates of Clostridioides difficile in China and its association with geographical regions and patient age

It is known that antibiotic usage is associated with the development of Clostridioides difficile infection (CDI), especially clindamycin, third-generation cephalosporins, and fuoroquinolones. Antibiotic resistance rates to many antibiotics varies a lot by study. We performed a study focused on antibiotic resistance in clinical isolates of C. difficile from more widespread geographic regions across China. Of 319 C. difficile isolates tested against 11 antibiotics, 313 (98.1%) were resistant to at least one antibiotic. The highest rate of resistance was to ciprofloxacin, clindamycin, and erythromycin across all age groups, similar to previous studies. However, all isolates were susceptible to metronidazole and vancomycin. Overall the resistance rate to tested antibiotics was lower than other reports in China except for chloramphenicol and meropenem. Genotype ST37/RT017 in clade 4 was resistant to more antibiotics than other types. Unexpectedly, RT078 isolates in this study were susceptible to almost all tested antibiotics. In addition, the proportion of multi-drug resistant (MDR) isolates observed (17%) in this study was much lower than several European studies (up to 55%) and a previous study in China (78%). Although isolates from patients aged between 65 and 85 were more resistant to antibiotics in comparison to other age groups, MDR isolates were still detected in children below 2-years of age. The highest percentage of MDR isolates was determined in South China, an area that is most developed economically. The clade 4, RT017 (ST37) has been associated with outbreaks in Europe and North America and is responsible for most C. difficile infections (CDIs) in Asia. In addition, RT017 is often clindamycin and fluoroquinolone resistant. This study provided a relatively comprehensive description of antibiotic resistance of C. difficile in China, and further elucidates the epidemiology and antibiotic resistance of clinical isolates of C. difficile in China at a national level.

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.

A phase 1 randomized study assessing safety and immunogenicity of two 3-dose regimens of a Clostridium difficile vaccine in healthy older Japanese adults

BACKGROUND

Clostridium difficile infection (CDI) is a major global cause of nosocomial and community-acquired infections. Despite potentially severe or fatal complications and frequent recurrence, no preventive vaccine is currently available. This randomized, observer-blinded, placebo-controlled phase 1 study in older Japanese adults evaluated safety and immunogenicity of an investigational C difficile vaccine containing a mixture of genetically detoxified and chemically inactivated toxoids, A and B.

METHODS

Healthy Japanese adults aged 65 to 85 years were randomized in a 3:3:2 ratio to receive 100 or 200 μg of C difficile vaccine or placebo, respectively, at 0, 1, and 6 months (month regimen) or 1, 8, and 30 days (day regimen). The primary objective was safety evaluation. Vaccine immunogenicity, the secondary objective, was determined by assessing toxin A- and toxin B-specific neutralizing antibody levels in human sera.

RESULTS

Local reactions were reported by up to 33.3% of subjects per dose in the month regimen; percentages were generally higher in the 200-μg group. Such reactions were all mild or moderate in severity and generally transient. No adverse events in the month regimen led to subject withdrawal, and no serious adverse events were considered vaccine related. Further enrollment and dosing in the day regimen were discontinued after 3 subjects in the 100-μg group reported severe redness after dose 2. In the month regimen study arm, immune responses as measured by toxin-neutralizing antibody geometric mean concentrations, geometric mean fold rises, and proportions of subjects achieving prespecified fold rises were generally higher in the 200-μg group, peaked at month 7, and remained elevated at month 12.

CONCLUSIONS

The C difficile vaccine candidate was safe, well tolerated, and immunogenic when administered to healthy older Japanese adults at 0, 1, and 6 months. Results support continued development of the vaccine for the prevention of CDI. ClinicalTrials.gov identifier: NCT02725437.

Epidemiology of Clostridium difficile infection in hospitalized adults and the first isolation of C. difficile PCR ribotype 027 in central China

Background

Clostridium difficile infection (CDI) is an emerging healthcare problem in the world. The purpose of this study was to perform a systematic epidemiological research of CDI in Tongji hospital, the central of China.

Methods

Stool samples from hospitalized adults suspected of CDI were enrolled. The diagnosis of CDI were based on the combination of clinical symptoms and laboratory results. Clinical features of CDI and non-CDI patients were compared by appropriate statistical tests to determine the risk factors of CDI. Multilocus sequence typing (MLST) was employed for molecular epidemiological analysis. Susceptibility testing and relevant antimicrobial agent resistance genes were performed as well.

Results

From June 2016 to September 2017, 839 hospitalized adults were enrolled. Among them, 107 (12.8%, 107/839) patients were C. difficile culture positive, and 73 (8.7%, 73/839) were infected with toxigenic C. difficile (TCD), with tcdA + tcdB+ strains accounting for 90.4% (66/73) and tcdA-tcdB+ for 9.6% (7/73). Meanwhile, two TCD strains were binary toxin positive and one of them was finally identified as CD027. Severe symptoms were observed in these two cases. Multivariate analysis indicated antibiotic exposure (p = 0.001, OR = 5.035) and kidney disease (p = 0.015, OR = 8.329) significantly increased the risk of CDI. Phylogenetic tree analysis demonstrated 21 different STs, including one new ST (ST467); and the most dominant type was ST54 (35.6%, 26/73). Multidrug-resistant (MDR) TCD were 53.4% (39/73); resistance to ciprofloxacin, erythromycin, and clindamycin were > 50%. Other antibiotics showed relative efficiency and all strains were susceptible to metronidazole and vancomycin. All moxifloxacin-resistant isolates carried a mutation in GyrA (Thr82 → Ile), with one both having mutation in GyrB (Ser366 → Ala).

Conclusions

Knowledge of epidemiological information for CDI is limited in China. Our finding indicated tcdA + tcdB+ C. difficile strains were the dominant for CDI in our hospital. Significant risk factors for CDI in our setting appeared to be antibiotic exposure and kidney disease. Metronidazole and vancomycin were still effective for CDI. Although no outbreak was observed, the first isolation of CD027 in center China implied the potential spread of this hypervirulent clone. Further studies are needed to enhance our understanding of the epidemiology of CDI in China.

Electronic supplementary material

The online version of this article (10.1186/s12879-019-3841-6) contains supplementary material, which is available to authorized users.

Epidemiological investigation of Clostridioides difficile colonization in Chinese community infants

Clostridioides difficile is a colonizer of the human gut; asymptomatic colonization has been reported to be more common in infants and is highly variable across regions even with no symptoms of diarrhea or death. Antibiotic treatment strategies might increase the antibiotic resistance of C. difficile. We performed a one-point study involving 1098 healthy infants (0-36 months) to address the deficiency of reports on C. difficile colonization in Chinese community infants. The C. difficile colonization rate was 22.8% (250/1098), and more than half of the strains (55.2%) were toxigenic isolates. Among the 138 toxigenic isolates, 111 were of the A⁺B⁺CDT^- genotype, 26 strains were A^-B⁺CDT^-, and one strain was A⁺B⁺CDT⁺. Fifteen different PCR ribotypes were found among the 250 isolates, and PCR-ribotype HB03 appeared to be dominant type, accounting for 19.6% (49/250). High levels of resistance to antimicrobial agents were observed. Our study showed that age and hospitalization before stool collection were positively correlated with the C. difficile colonization rate, whereas the delivery term was negatively related to the colonization rate. Particular attention should be paid to the increasing resistance of C. difficile to rifamycin.

The first isolation of Clostridium difficile RT078/ST11 from pigs in China

We investigated the molecular characteristics and antimicrobial susceptibility of Clostridium difficile isolated from animals in China. We obtained 538 rectal swabs from pigs, chickens and ducks in 5 provinces during 2015 and 2016. C. difficile isolates were characterized by detection of toxin genes, multilocus sequence typing and ribotyping. And antimicrobial susceptibility testing was performed using the agar dilution method. Out of 538 samples, 44 (8.2%) were C. difficile positive with high prevalence in pigs (n = 31). Among these, 39 (88.6%) were toxigenic including 14 (31.8%) that were A+B+CDT+ and 13 (29.5%) A+B+. The remaining 12 (27.3%) were A-B+. We identified 7 ST types and 6 PCR ribotypes. The most predominant type was ST11/RT078 with toxin profile A+B+CDT+ and all were isolated from piglets with diarrhea. ST109 isolates possessed two different toxigenic profiles (A-B-CDT- and A-B+CDT-) and although it was not the most prevalent sequence type, but it was widely distributed between chickens, ducks and pigs in the 5 provinces. All C. difficile isolates were fully susceptible to vancomycin, metronidazole, fidaxomicin, amoxicillin/clavulanate and meropenem but retained resistance to 4 or 5 of the remaining antibiotics, especially cefotaxime, tetracycline, ciprofloxacin, cefoxitin. The RT078/ST11 isolates were simultaneously resistant to cefotaxime, tetracycline, cefoxitin, ciprofloxacin and imipenem. This is the first report of the molecular epidemiology of C. difficile isolated from food animals in China. We identified the epidemic strain RT078/ST11 as the predominate isolate among the animals we screened in our study.

Clostridium difficile-associated Diarrhea in Developing Countries: A Systematic Review and Meta-Analysis

Introduction

The prevalence of Clostridium difficile infection is rapidly increasing worldwide, but prevalence is difficult to estimate in developing countries where awareness, diagnostic resources, and surveillance protocols are limited. As diarrhea is the hallmark symptom, we conducted a systematic review and meta-analysis to determine the prevalence and incidence of C. difficile infection in patients in these regions who presented with diarrhea.

Methods

We conducted a systematic literature search of MEDLINE/PubMed, Scopus, and Latin-American and Caribbean Health Sciences Literature databases to identify and analyze data from recent studies providing prevalence or incidence rates of C. difficile-associated diarrhea in developing countries within four regions: Africa–Middle East, developing Asia, Latin America, and China. Our objectives were to determine the current prevalence and incidence density rates of first episodes of C. difficile-associated diarrhea in developing countries.

Results

Within the regions included in our analysis, prevalence of C. difficile infection in patients with diarrhea was 15% (95% CI 13–17%) (including community and hospitalized patients), with no significant difference across regions. The incidence of C. difficile infection in 17 studies including this information was 8.5 per 10,000 patient-days (95% CI 5.83–12.46). Prevalence was significantly higher in hospitalized patients versus community patients (p  = 0.0227).

Conclusion

Our prevalence estimate of 15% is concerning; however, low awareness and inconsistent diagnostic and surveillance protocols suggest this is markedly underestimated. Enhanced awareness and management of C. difficile infection in patients with diarrhea, along with improvements in infection control and surveillance practices, should be implemented to reduce prevalence of C. difficile-associated diarrhea in developing countries.

Funding

Pfizer Inc.

Electronic supplementary material

The online version of this article (10.1007/s40121-019-0231-8) contains supplementary material, which is available to authorized users.

Clostridium Difficile Infection: An Immunological Conundrum

The lack of comprehensive understanding of the way immunity backfires on incidence and complications has made Clostridium difficile infection (CDI), the infectious disease of our times, as evidenced by in the parallel course it follows along epidemic of chronic degenerative diseases. Within these ailments, if as suspected the main effect of Clostridium difficile A and B toxins depends on inflammation, then aberrant immune function due to antibiotics would explain IBD triggering after treatment but also, the higher incidence and mortality surrounding disorders that are inflammatory and/or that show abatement of neutrophils. This review will discuss severity of the disease in terms of challenges to immunity during the progression of acute illness. We will identify the common signals in the communication between microbiota and inflammatory cells, as well as the sequestration of the regulatory network by Clostridium difficile, which leads to tissue damage and prevents its elimination from intestinal lumen.

Co-infection of Clostridioides (Clostridium) difficile GMU1 and Bacillus cereus GMU2 in one patient in Guizhou, China

Clostridioides (Clostridium) difficile and Bacillus cereus infections are frequently reported in human individually. However, co-infection of both pathogens in human is extremely rare. In the present study, we reported a case of human enteric disease caused by co-infection of C. difficile and B. cereus in Guizhou, China. The 16S rDNA sequencing result showed that C. difficile GMU1 and B. cereus GMU2 were most related to C. difficile ATCC 9689 and B. cereus ATCC 14579. The toxin genotype of C. difficile GMU1 and B. cereus GMU2 were tcdA⁺tcdB⁺tcdC⁺ and bceT⁺nheA⁺nheB⁺nheC⁺, respectively. Cytotoxicity assay demonstrated that C. difficile GMU1 produced significantly higher toxin B compare to C. difficile 630 stain. In contrast, B. cereus GMU2 has comparable NheA toxin productivity compare to previous report. The antimicrobial susceptibility test showed that the combination of ampicillin and vancomycin was most efficient to inhibit both C. difficile GMU1 and B. cereus GMU2.

Time-resolved transcriptome analysis of Clostridium difficile R20291 response to cysteine

The incidence of Clostridium difficile infection has been steadily rising over the past decade. The increase in the rate of incidence is associated with the specific NAP1/BI/027 strains which are "hypervirulent" and have led to several large outbreaks since their emergence. However, the relation between these outbreaks and virulence regulation mechanisms remains unclear. It has been reported that the major virulence factor TcdA and TcdB in C. difficile could be repressed by cysteine. Here, we investigated the functional and virulence-associated regulation of C. difficile R20291 response to cysteine by using a time-resolved genome-wide transcriptome analysis. Dramatic changes of gene expression in C. difficile revealed functional processes related to transport, metabolism, and regulators in the presence of cysteine during different phases of growth. Flagellar and ribosomal genes were significantly down-regulated in long-term response to cysteine. Many NAP1/BI/027- specific genes were also modulated by cysteine. In addition, cdsB inactivation in C. difficile R20291 could remove the repression of toxin synthesis but could not remove the repression of butyrate production in the presence of cysteine. This suggests that toxin synthesis and butyrate production might have different regulatory controls in response to cysteine. Altogether, our research provides important insights into the regulatory mechanisms of C. difficile response to cysteine.

Molecular epidemiology of Clostridium difficile in two tertiary care hospitals in Shandong Province, China

Purpose

The incidence and severity of Clostridium difficile infection (CDI) have markedly increased over the past decade. However, there is very limited epidemiological data on CDI in China so far, specifically no data in Shandong Province. The aim of this study was to evaluate diagnostic algorithm for CDI and to gain data on molecular epidemiology of CDI in the Shandong Province of China.

Materials and methods

Nonrepetitive unformed fecal specimens (n=504) were investigated by the glutamate dehydrogenase (GDH), C. difficile toxin A&B (CDAB) tests and toxigenic culture. Furthermore, 85 isolates were characterized by toxin gene detection, multilocus sequence typing, ribotyping and antimicrobial susceptibility testing.

Results

The algorithm of combining GDH and CDAB tests could define diagnosis of 54.2% CDI cases and excluded 90% of non-CDI. Further adding the toxigenic culture to the algorithm enhanced the detection sensitivity to 100%. Toxigenic strains comprised 84.7% of isolates, including A+B+CDT− (71.8%, 61/85), A−B+CDT− (11.8%, 10/85) and A+B+CDT+ (1.2%, 1/85) isolates. RT046/ST35 (13.9%, 10/72), RT014/ST2 (12.5%, 9/72) and RT017/ST37 (12.5%, 9/72) were the more common genotypes among toxigenic C. difficile strains. The clinical severity score of A−B+CDT− toxin genes genotype (3.50±0.85) was significantly higher than the A+B+CDT− type (2.59±0.93) (P<0.05). RT046/ST35 isolates were highly prevalent and had high clinical severity scores (3.80±0.92). Variations in resistance from different sequence types (STs) were observed. Toxigenic strains showed higher resistance rates to erythromycin, clindamycin and ciprofloxacin compared to nontoxigenic strains (P<0.05).

Conclusion

The epidemiology of C. difficile in Shandong Province differed from other regions in China. Comprehensive optimized diagnosis strategy and continuous surveillance should be established and applied in order to curb the spread of toxigenic C. difficile strains, especially for hospitalized patients.

Incidence and Outbreak of Healthcare-Onset Healthcare-Associated Clostridioides difficile Infections Among Intensive Care Patients in a Large Teaching Hospital in China

Background:Clostridioides difficile infection (CDI) is an important cause of morbidity and mortality among hospitalized patients. In China, however, hospital staff do not routinely test for CDI, leading to under-diagnosis and poor patient outcomes. Locally generated CDI data can help assess the magnitude of the problem and strengthen approaches for CDI prevention and control.

Methods: We prospectively monitored hospital-onset hospital-associated (HOHA) CDI in four intensive care units (ICUs) from June 2013 to September 2014 in a large teaching hospital in China. We collected clinical information from all ICU patients with ≥ 3 episodes of diarrhea occurring within a 24-h period at least 48 h following admission (suspect case definition). Stool specimens were collected from all suspect cases of CDI and cultured for C. difficile. Polymerase chain reaction (PCR) was used to detect toxin genes from positive isolates; multi-locus sequence typing (MLST) was used for typing and identifying novel strains. We estimated the incidence rate as the number of HOHA CDI cases per 10,000 patient days; 95% confidence intervals were generated to assess rate differences between the four ICUs.

Results: A total of 593 hospital-onset diarrhea patients met the suspect case definition during the study period. Of these, 47 patients (8%) were positive for C. difficile and toxin genes. The HOHA-CDI incidence rate was 14.1 cases per 10,000 patient days (95% CI: 10.5–18.6). Six patients with HOHA CDI died. ST54 (n = 14, 20%) was the most common type of HOHA-CDI strain circulating in the hospital during the study period and was linked to a temporal cluster (outbreak) involving two (NICU and GICU) of the four ICUs.

Conclusion: HOHA-CDI occurs among ICU patients at this teaching hospital, supporting the importance of routine testing for CDI. Information on strain distribution can help detect CDI outbreaks. Detection of ST54 strain in a temporal cluster suggests possible gaps in infection control practices that should be investigated and addressed as needed.

Coinfection with 2 Clostridium difficile ribotypes in China: A case report

RATIONALE

Clostridium difficile infections (CDIs) have been reported in China, but detailed clinical symptoms of coinfection by 2 C difficile ribotypes have not been documented.

PATIENTS CONCERNS

An 83-year-old male with a 10-day history of diarrhea and urinary tract infection was admitted to the hospital. The patient had received ofloxacin for several days, but his clinical response was poor. Laboratory workup revealed high white blood cell (WBC), serum creatinine (Scr), and C-reactive protein (CRP) levels. Based on these abnormal lab results, rapid detection of glutamate dehydrogenase and toxin A and B was performed.

DIAGNOSIS

Severe CDI.

INTERVENTIONS

Oral vancomycin was administered for 8 days.

OUTCOMES

Diarrhea symptoms improved and C difficile culture was negative after oral vancomycin administration for 8 days. Clostridium difficile was isolated from 3 consecutive stool samples at 2-day intervals because the patient was admitted to the hospital. Polymerase chain reaction ribotyping revealed ribotype (RT) 017 in the first 2 samples and RT 001 in the third sample. RT 017 caused significantly higher increases in the levels of WBC, Scr, and CRP than RT 001.

LESSONS

It is necessary to improve clinicians' awareness of CDI and reduce the severity of CDI caused by RT 017 in China.

The role of the microbiome and the use of probiotics in gastrointestinal disorders in adults in the Asia-Pacific region - background and recommendations of a regional consensus meeting

The Asia-Pacific region is diverse, with regard to ethnicity, culture, and economic development incorporating some of the world's least and most developed nations. Gastrointestinal diseases are common in the Asia-Pacific region, and their prevalence, presentation, and management vary considerably within the region. There is growing evidence for an important role for the human gut microbiota in gastrointestinal health. As a consequence, geographic variations in the composition of the gut microbiota may contribute to variations in both the prevalence and response to therapy of specific diseases. Probiotics have been proposed as a valuable option in the prevention and treatment of a number of gastrointestinal illnesses, but the quality of available evidence to support their efficacy is variable. A meeting of international experts in adult and pediatric gastroenterology was held at the Sorbonne University, Paris, France, on April 11 and 12, 2016, to discuss current evidence supporting the use of probiotics in gastrointestinal disorders in the Asia-Pacific region. This article provides an overview of the discussions held at this meeting and recommends the formation of an Asia-Pacific Consortium on Gut Microbiota similar to those established in Europe and North America.

The Recent Emergence of Clostridium difficile Infection in Romanian Hospitals is Associated with a High Prevalence of Polymerase Chain Reaction Ribotype 027

Aims:

To investigate the epidemiology of Clostridium difficile infection in Romanian hospitals.

Methods:

A survey was conducted at nine hospitals throughout Romania between November 2013 and February 2014.

Results:

The survey identified 393 patients with Clostridium difficile infection. The median age was 67 years (range: 2-94 years); 56% of patients were aged >65 years. The mean prevalence of Clostridium difficile infection was 5.2 cases per 10.000 patient-days. The highest prevalences were 24.9 and 20 per 10.000 patient-days in hospitals specializing in gastroenterology and infectious diseases, respectively. Clostridium difficile infections were health care-associated in 70.5% patients and community-acquired in 10.2%. The origin was not determined in 19.3%. Clostridium difficile infection was severe in 12.3% of patients, and the in-hospital all-cause mortality was 8.8%. Polymerase chain reaction ribotype 027 had the highest prevalence in all participating hospitals and represented 82.6% of the total ribotyped isolates. The minimum inhibitory concentration of moxifloxacin was >4 μg/mL for 59 of 80 tested isolates (73.8%). Of 59 isolates, 54 were highly resistant to moxifloxacin (minimum inhibitory concentration ≥32 μg/mL), and the majority were polymerase chain reaction ribotype 027 (p<0.0001).

Conclusion:

The ribotype 027 was the predominant cause of Clostridium difficile infections in Romania. In some specialized hospitals, the prevalence of Clostridium difficile infection was higher than the European mean prevalence, and this demonstrates the need for strict adherence to infection control programs.

Identifying predictive features of Clostridium difficile infection recurrence before, during, and after primary antibiotic treatment

BACKGROUND

Colonization by the pathogen Clostridium difficile often occurs in the background of a disrupted microbial community. Identifying specific organisms conferring resistance to invasion by C. difficile is desirable because diagnostic and therapeutic strategies based on the human microbiota have the potential to provide more precision to the management and treatment of Clostridium difficile infection (CDI) and its recurrence.

METHODS

We conducted a longitudinal study of adult patients diagnosed with their first CDI. We investigated the dynamics of the gut microbiota during antibiotic treatment, and we used microbial or demographic features at the time of diagnosis, or after treatment, to predict CDI recurrence. To check the validity of the predictions, a meta-analysis using a previously published dataset was performed.

RESULTS

We observed that patients' microbiota "before" antibiotic treatment was predictive of disease relapse, but surprisingly, post-antibiotic microbial community is indistinguishable between patients that recur or not. At the individual OTU level, we identified Veillonella dispar as a candidate organism for preventing CDI recurrence; however, we did not detect a corresponding signal in the conducted meta-analysis.

CONCLUSION

Although in our patient population, a candidate organism was identified for negatively predicting CDI recurrence, results suggest the need for larger cohort studies that include patients with diverse demographic characteristics to generalize species that robustly confer colonization resistance against C. difficile and accurately predict disease relapse.

Simultaneous detection and characterization of toxigenic Clostridium difficile directly from clinical stool specimens

We employed a multiplex polymerase chain reaction (PCR) coupled with capillary electrophoresis (mPCR-CE) targeting six Clostridium difficile genes, including tpi, tcdA, tcdB, cdtA, cdtB, and a deletion in tcdC for simultaneous detection and characterization of toxigenic C. difficile directly from fecal specimens. The mPCR-CE had a limit of detection of 10 colony-forming units per reaction with no cross-reactions with other related bacterial genes. Clinical validation was performed on 354 consecutively collected stool specimens from patients with suspected C. difficile infection and 45 isolates. The results were compared with a reference standard combined with BD MAX Cdiff, real-time cell analysis assay (RTCA), and mPCR-CE. The toxigenic C. difficile species were detected in 36 isolates and 45 stool specimens by the mPCR-CE, which provided a positive rate of 20.3% (81/399). The mPCR-CE had a specificity of 97.2% and a sensitivity of 96.0%, which was higher than RTCA (x² = 5.67, P = 0.017) but lower than BD MAX Cdiff (P = 0.245). Among the 45 strains, 44 (97.8%) were determined as nonribotype 027 by the mPCR-CE, which was fully agreed with PCR ribotyping. Even though ribotypes 017 (n = 8, 17.8%), 001 (n = 6, 13.3%), and 012 (n = 7, 15.6%) were predominant in this region, ribotype 027 was an important genotype monitored routinely. The mPCR-CE provided an alternative diagnosis tool for the simultaneous detection of toxigenic C. difficile in stool and potentially differentiated between RT027 and non-RT027.

Nosocomial transmission of Clostridium difficile Genotype ST81 in a General Teaching Hospital in China traced by whole genome sequencing

Clostridium difficile infection (CDI) is increasingly recognized globally as a cause of significant morbidity and mortality. This study aimed to provide insight into the various dynamics of C. difficile transmission and infection in the hospital. We monitored the toxin and resistance profiles as well as evolutionary relationships of C. difficile strains to determine the epidemiology over time in a teaching hospital in Shanghai, China between May 2014 and August 2015. The CDI incidence of inpatients and outpatients were 67.7 cases and 0.3 cases per 100,000 patient-days, with a nosocomial patient-environment-patient transmission in May and June 2015. C. difficile genotype ST81, a clone with tcdA-negative and tcdB-positive, was not only the most common strain (30.8%, 28/91) but also had much higher resistance rates to clindamycin and moxifloxacin compared with non-ST81 genotypes. Hospitalized patients infected with ST81 genotypes were over 65 years of age and had more comorbidities, however patients infected with ST81 presented with less clinical symptoms than non-ST81 infected patients. This study provides initial epidemiological evidence that C. difficile ST81 is a successful epidemic genotype that deserves continuous surveillance in China.

High in vitro activity of fidaxomicin against Clostridium difficile isolates from a university teaching hospital in China

BACKGROUND

Clostridium difficile infection (CDI) is a significant cause of morbidity and mortality in both the acute care setting and the wider healthcare system. The purpose of this study was to evaluate the in vitro activity of fidaxomicin against C. difficile isolates from a university teaching hospital in China.

METHODS

One hundred and one C. difficile isolates were collected and analyzed for toxin genes by multiplex PCR. The toxin gene positive strains were also typed by multilocus sequence typing (MLST) and PCR-ribotyping. The MICs of the isolates were determined against fidaxomicin, metronidazole, vancomycin, tigecycline and moxifloxacin, by the agar dilution method.

RESULTS

All the 101 isolates exhibited low MICs to fidaxomicin (0.032-1 mg/L), metronidazole (0.125-1 mg/L), vancomycin (0.25-2 mg/L) and tigecycline (0.016-0.5 mg/L). Tigecycline showed the lowest geometric mean MIC value (0.041 mg/L), followed by fidaxomicin (0.227 mg/L), metronidazole (0.345 mg/L), and vancomycin (0.579 mg/L). About 35% of the strains (n = 35) were resistant to moxifloxacin, and the resistance rate to moxifloxacin for A-B+CDT- isolates (85.0%) was much higher than that of A+B+CDT- (15.7%) and A-B-CDT- (29.2%) isolates (P < 0.001). The MIC values of fidaxomicin, metronidazole, vancomycin and moxifloxacin against the 3 ST1 isolates were higher than for other STs. All the 28 moxifloxacin-resistant toxigenic isolates carried a mutation either in gyrA or/and gyrB.

CONCLUSION

Fidaxomicin exhibited high antimicrobial activity against all C. difficile isolates tested, which shows promise as a new drug for treating Chinese CDI patients.

Whole genome sequences of three Clade 3 Clostridium difficile strains carrying binary toxin genes in China

Clostridium difficile consists of six clades but studies on Clade 3 are limited. Here, we report genome sequences of three Clade 3 C. difficile strains carrying genes encoding toxin A and B and the binary toxin. Isolates 103 and 133 (both of ST5) and isolate 106 (ST285) were recovered from three ICU patients. Whole genome sequencing using HiSeq 2500 revealed 4.1-Mb genomes with 28–29% GC content. There were ≥1,104 SNP between the isolates, suggesting they were not of a single clone. The toxin A and B gene-carrying pathogenicity locus (PaLoc) of the three isolates were identical and had the insertion of the transposon Tn6218. The genetic components of PaLoc among Clade 3 strains were the same with only a few nucleotide mutations and deletions/insertions, suggesting that the Tn6218 insertion might have occurred before the divergence within Clade 3. The binary toxin-genes carrying CDT locus (CdtLoc) of the three isolates were identical and were highly similar to those of other Clade 3 strains, but were more divergent from those of other clades. In conclusion, Clade 3 has an unusual clade-specific PaLoc characteristic of a Tn6218 insertion which appears to be the main feature to distinguish Clade 3 from other C. difficile.

Molecular Epidemiology of Clostridium difficile Infection in Hospitalized Patients in Eastern China

Few studies on risk factors for and transmission of Clostridium difficile infection (CDI) in China have been reported. A cross-sectional study was conducted for 3 years in eastern China. Consecutive stool specimens from hospitalized patients with diarrhea were cultured for C. difficile. C. difficile isolates from these patients then were analyzed for toxin genes, genotypes, and antimicrobial resistance. A severity score for the CDI in each patient was determined by a blinded review of the medical record, and these scores ranged from 1 to 6. A total of 397 out of 3,953 patients (10.0%) with diarrhea were found to have CDI. Severity of CDI was mild to moderate, and the average (± standard deviation) severity score was 2.61 ± 1.01. C. difficile was isolated from stool specimens in 432 (10.9%) of all the patients who had diarrhea. C. difficile genotypes were determined by multilocus sequence analysis and PCR ribotyping; sequence type 37 (ST37)/ribotype 017 (RT017) (n = 68, 16.5%) was the dominant genotype. Eleven patients (16.2%) with this genotype had a CDI severity score of 5. Overall, three RTs and four STs were predominant; these genotypes were associated with significantly different antimicrobial resistance patterns in comparison to all genotypes (χ² = 79.56 to 97.76; P < 0.001). Independent risk factors associated with CDI included age greater than 55 years (odds ratio [95% confidence interval], 26.80 [18.76 to 38.29]), previous hospitalization (12.42 [8.85 to 17.43]), previous antimicrobial treatment within 8 weeks (150.56 [73.11 to 310.06]), hospital stay more than 3 days before sampling (2.34 [1.71 to 3.22]), undergoing chemotherapy (3.31 [2.22 to 4.92]), and undergoing abdominal surgery (4.82 [3.54 to 6.55]). CDI is clearly a problem in eastern China and has a prevalence of 10.0% in hospitalized patients. Among risk factors for CDI, the advanced age threshold was younger for Chinese patients than that reported for patients in developed countries.

The incidence and drug resistance of Clostridium difficile infection in Mainland China: a systematic review and meta-analysis

It has been widely reported that the incidence and severity of Clostridium difficile infection (CDI) have increased dramatically in North America and Europe. However, little is known about CDI in Mainland China. In this study, we aimed to investigate the incidence of CDI and the main epidemic and drug-resistant strains of C. difficile in Mainland China through meta-analysis of related studies published after the year 2010. A total of 51 eligible studies were included. The pooled incidence of toxigenic C. difficile among patients with diarrhoea was 14% (95% CI = 12–16%). In Mainland China, ST-37 and ST-3 were the most prevalent strains; fortunately, hypervirulent strains, such as ST-1 (BI/NAP1/027) and ST-11 (RT 078), have only occurred sporadically to date. The rates of C. difficile resistance to ciprofloxacin (98.3%; 95% CI = 96.9–99.7%), clindamycin (81.7%; 95% CI = 76.1–87.3%) and erythromycin (80.2%; 95% CI = 73.5–86.9%) are higher than in other counties; however, none of the C. difficile isolates reported in Mainland China were resistant to metronidazole (n/N = 0/960), vancomycin (n/N = 0/960), tigecycline (n/N = 0/41) or piperacillin/tazobactam(n/N = 0/288).

Molecular Epidemiology and Antimicrobial Susceptibility of Clostridium difficile Isolates from a University Teaching Hospital in China

While the developed world has seen a significant increase in the number of scientific articles on Clostridium difficile infection (CDI), the developing world still lags behind on this subject due to limited laboratory capacity, low awareness, and limited surveillance of this problem. As such, CDI is considered a neglected but potentially huge problem in developing countries. The major aim of this study was to systemically evaluate the utility of several molecular typing tools for CDI, including their relevance in epidemiological studies in developing countries such as China. A total of 116 non-repetitive toxigenic C. difficile isolates from Chinese patients, were studied. The isolates comprised 83 (71.6%) A+B+CDT- isolates, 27 (23.3%) A-B+CDT- isolates, and 6 (5.1%) A+B+CDT+ isolates. Typing methods evaluated included multilocus variable-number tandem-repeat analysis, PCR ribotyping, multilocus sequence typing, and sequencing of slpA and tcdC genes, which identified 113, 30, 22, 18, and 8 genotypes each and exhibited discriminatory powers of 0.999, 0.916, 0.907, 0.883, and 0.765, respectively. Compared to A+B+ strains, A-B+ strains exhibited higher prevalence of drug resistance to clindamycin, erythromycin, levofloxacin, rifampicin, rifaximin, and tetracycline. Furthermore, drug resistance rates of strains with different PCR ribotypes differed, supporting the importance of molecular typing in management and control of CDI. Based on our earlier suggestion to improve the diagnostic laboratory capacity of CDI in developing countries, setting up efficient surveillance programs complemented by relevant molecular typing methods is warranted.