Clostridium difficile infections in China

Antibiotics Associated With Clostridium difficile Infection

Introduction Clostridium difficile (C. difficile) is one of the major causes of diarrhea transmitted by the fecal-oral route. C. difficile type BI/NAP1/027 is responsible for the most severe C. difficile infection (CDI). It is a major cause of antibiotic-associated diarrhea followed by Clostridium perfringens, Staphylococcus aureus,and Klebsiella oxytoca. Historically, clindamycin, cephalosporins, penicillins, and fluoroquinolones were related to CDI. We conducted this study to evaluate the antibiotics associated with CDI in recent times. Methods We conducted a retrospective, single-center study over a period of eight years. A total of 58 patients were enrolled in the study. Patients with diarrhea and positive C. difficile toxin in stool were evaluated for antibiotics given, age, presence of malignancy, previous hospital stay for more than three days in the last three months, and any comorbidities. Results Among patients who developed CDI, prior antibiotics for at least four days duration were given in 93% (54/58) of patients. The most common antibiotics associated with C. difficile infection were piperacillin/tazobactam in 77.60% (45/58), meropenem in 27.60% (16/58), vancomycin in 20.70% (12/58), ciprofloxacin in 17.20% (10/58), ceftriaxone in 16% (9/58), and levofloxacin in 14% (8/58) of patients, respectively. Seven percent (7%) of patients with CDI did not receive any prior antibiotics. Solid organ malignancy was present in 67.20% and hematological malignancy in 27.60% of CDI patients. Ninety-eight percent (98%, 57/58) of patients treated with proton pump inhibitors, 93% of patients with a previous hospital stay for more than three days, 24% of patients with neutropenia, 20.1% of patients aged more than 65 years, 14% of patients with diabetes mellitus, and 12% of patients with chronic kidney disease also developed C. difficile infection. Conclusion The antibiotics associated with C. difficile infection are piperacillin/tazobactam, meropenem, vancomycin, ciprofloxacin, ceftriaxone, and levofloxacin. Other risk factors for CDI are proton pump inhibitor use, prior hospital admission, solid organ malignancy, neutropenia, diabetes mellitus (DM), and chronic kidney disease (CKD).

Frequency of Clostridioides difficile Infection Among Hospitalized Patients in Kerman City, Iran

Background: Clostridioides difficile is one of the major causes of nosocomial infections, being responsible for 15 to 25% of antibiotic-associated diarrhea. It is important to determine the epidemiology and prevalence of this bacterium at hospitals and healthcare centers. Objectives: This study aims to investigate the prevalence of C. difficile infection (CDI) by identifying toxigenic isolates of C. difficile in different wards of the hospital. Methods: A total of 417 diarrheal stool samples were taken from hospitalized patients in different wards of three educational hospitals in Kerman City, Iran from 2018 to 2020. The samples were cultured on cycloserine-cefoxitin fructose agar and C. difficile suspected colonies were isolated. Identification of the cdd-3 gene for definitive diagnosis of C. difficile and identification of toxin genes in the positive isolates was performed using the PCR method. Results: A total of 68 isolates (16.3%) of C. difficile were isolated from the specimens. Besides, 8.6% (36/417) and 7.6% (32/417) of the isolates were toxigenic and nontoxigenic, respectively; thus, the prevalence of CDI was 8.6%. Most of the toxigenic isolates had the A+B+CDT- toxin phenotype. The highest prevalence of CDI was observed in males, ICU ward, and age group of 41 - 60. Conclusions: A total of 8.6% of hospitalized patients with diarrhea were infected with C. difficile. The prevalence of CDI in Kerman City is lower than that in Europe, East Asia, and other parts of Iran, but it is almost the same as that in the Middle East.

A Spore-Forming Probiotic Supplement Improves the Intestinal Immune Response and Protects the Intestinal Health During Recurrent Clostridioides difficile Colonization in Mice

BACKGROUND

Around 15%-30% of patients develop recurrent Clostridioides difficile infection (CDI) as conventional therapies disrupt protective gut microbiota. We tested if supplementation with a spore-forming probiotic would protect intestinal health in a mouse model of recurrent CD colonization.

METHODS

Methods: Female CF-1 mice were exposed to CD spores (4-log₁₀ colony-forming units/10 μL) and then randomly assigned to receive either saline (CD-S) or probiotic (CD-PRO). Control mice received only saline (control). Following confirmation of initial CD colonization, mice were treated with vancomycin (10 days). After 5 days, mice recolonized with CD were treated again with vancomycin (10 days) and euthanized 5 days later. Fecal samples were collected at select time points for bacterial analysis. Following euthanasia, blood samples, cecum contents, and the intestine were collected for analysis.

RESULTS

Probiotic supplementation mitigated the antibiotic-induced changes in cecum weight (P < .001). Probiotic-supplemented mice had increased messenger RNA expression of several immune parameters, accompanied by lower serum iron levels compared with CD-S mice (P < .05). Lower expressions of TNF α and calprotectin (P ≤ .05) were observed in CD-PRO mice compared with CD-S. The probiotics also supported the expression of intestinal tight junction proteins, which were diminished in the proximal colon of CD-S mice (P < .05).

CONCLUSION

Mice supplemented with targeted spore-forming probiotics exhibited improved immune responses and nutrition immunity properties, which were linked with less inflammation and enhanced intestinal barrier proteins during recurrent CD colonization.

Using DNA Immunization to Elicit Monoclonal Antibodies in Mice, Rabbits, and Humans

In recent vaccine studies, DNA immunization was found to effectively stimulate both innate and adaptive immunities to elicit high levels of antigen-specific antibody responses. The DNA molecule itself can activate multiple pathways of innate immunity. The in vivo production of antigens allows for presentation by major histocompatibility complexes, so that T-cell responses are generated to help in the development of antigen-specific B cells, leading to high-affinity antibody response. By using the same process, DNA immunization should also be effective at producing functionally potent monoclonal antibodies (mAbs). Furthermore, the in vivo expressed proteins can maximally maintain the native structures and go through appropriate post-transcriptional modifications. By combining such advantages, DNA immunization can be expected to play more important roles in the future to elicit mAbs against difficult targets from a wide range of host systems. The current report shares our group's experience in using DNA immunization to elicit mAbs in the mouse, rabbit, and human models.

Evidence-based consensus on opportunistic infections in inflammatory bowel disease (republication)

Inflammatory bowel disease (IBD) patients are a high-risk population for opportunistic infections. The IBD group of the Chinese Society of Gastroenterology of the Chinese Medical Association organized an expert group to discuss and develop this consensus opinion. This consensus opinion referenced clinical study results from China and other countries to provide guidance for clinical practices. Eight major topics, including cytomegalovirus infection, Epstein-Barr virus infection, viral hepatitis, bacterial infection, Mycobacterium tuberculosis infection, fungal infection, parasitic infection, and vaccines were introduced in this article.

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

Clostridium difficile infection (CDI) is associated with risk for severe disease and high mortality. Little is known about the extent of hospital-acquired CDI in Mainland China. In this study, we aimed to investigate the annual CDI incidence, bacterial genotypes, risk factors for severe CDI and survival over a 7-year period. A total of 307 hospital-acquired CDI patients were enrolled, and 70.7% of these cases were male. CDI incidence was 3.4 per 10,000 admissions. Thirty-three different sequence types (STs) were identified, among which ST-54 (18.2%), ST-35 (16.6%) and ST-37 (12.1%) were the most prevalent. During the follow-up period, 66 (21.5%) patients developed severe CDI and 32 (10.4%) patients died in 30 days. Multivariate analysis revealed that bloodstream infection, pulmonary infection and C-reactive protein were significantly associated with severe CDI. After adjustment for potential confounders, old age, bloodstream infection, fever, mechanical ventilation, connective tissue disease, macrolide use and hypoalbuminaemia were independently associated with 30-day mortality in patients with CDI. The CDI prevalence has been low and stable in our center, and STs of Clostridium difficile were different from dominant STs in Western countries. Our data emphasize the need of continued education and surveillance of CDI to reduce the CDI burden in China.

Colon-Targeted Delivery of IgY Against Clostridium difficile Toxin A and B by Encapsulation in Chitosan-Ca Pectinate Microbeads

This study investigated the use of a newly developed chitosan-Ca pectinate microbead formulation for the colon-targeted delivery of anti-A/B toxin immunoglobulin of egg yolk (IgY) to inhibit toxin binding to colon mucosa cells. The effect of the three components (pectinate, calcium chloride, and chitosan) used for the microbead production was examined with the aim of identifying the optimal levels to improve drug encapsulation efficiency, swelling ratio, and cumulative IgY release rate. The optimized IgY-loaded bead component was pectin 5% (w/v), CaCl₂ 3% (w/v), and chitosan 0.5% (w/v). Formulated beads were spherical with 1.2-mm diameter, and the drug loading was 45%. An in vitro release study revealed that chitosan-Ca pectinate microbeads inhibited IgY release in the upper gastrointestinal tract and significantly improved the site-specific release of IgY in the colon. An in vivo rat study demonstrated that 72.6% of biologically active IgY was released specifically in the colon. These results demonstrated that anti-A/B toxin IgY-loaded chitosan-Ca pectinate oral microbeads improved IgY release behavior in vivo, which could be used as an effective oral delivery platform for the biological treatment of Clostridium difficile infection (CDI).

Conventional and alternative treatment approaches for Clostridium difficile infection

Clostridium difficile-associated disease continues to be one of the leading health concerns worldwide. C. difficile is considered as a causative agent of nosocomial diarrhea that causes serious infection, which may result in death. The incidences of C. difficile infection (CDI) in developed countries have become increasingly high which may be attributed to the emergence of newer epidemic strains, extensive use of antibiotics, and limited alternative therapies. The available treatment options against CDI are expensive and promote resistance. Therefore, there is urgent need for new approaches to meet these challenges. This review discusses the current understanding of CDI, the existing clinical treatment strategies and future potential options as antidifficile agents based on the available published works.

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).

Clinical characteristics of Clostridium difficile-associated diarrhea among patients in a tertiary care center in China

Objective:

This study investigated the incidence, risk factors, and clinical characteristics of Clostridium difficile-associated diarrhea (CDAD) in Chinese patients.

Methods:

Fecal specimens of patients with antibiotic-associated diarrhea (AAD) were collected to test C. difficile toxin A and B using enzyme-linked fluorescent assay to identify CDAD. By adopting a nested case-control design, the matched people (ratio 1:3) without AAD were included as controls.

Results:

Out of 56,172 inpatients, 39,882 (71.0%) used antibiotics, 470 suffered from AAD, and 93 were diagnosed with CDAD. The incidence of nosocomial CDAD was 166 per 100,000. The proportion of CDAD in AAD was 19.8%. CDAD patients presented with more severe clinical manifestations and exhibited more concurrent illness. Logistic regression analysis showed the risk factors of CDAD: advanced age, nasogastric tube-feeding, high APACHE II scores, high level of serum C-reaction protein, low level of serum albumin, severe underlining disease or comorbidity, and number of antibiotic intake. Twenty-nine patients (31.2%) were cured with vancomycin, 54 (58.1%) were cured after dual therapy of vancomycin plus metronidazole, 7 (7.5%) died of underlying diseases aggravated with CDAD, and 3 (3.2%) were transferred to other hospitals for personal reasons.

Conclusion:

The incidence of nosocomial CDAD in China was high. Some risk factors could predispose CDAD.

Prevention of Clostridium difficile Infection With Probiotics

Despite advances in the diagnosis and treatment of Clostridium difficile infection (CDI) and prevention efforts to reduce the spread of C. difficile, CDI remains a significant challenge to healthcare systems worldwide. Further advances in prevention of CDI may need to focus on those who continue to be exposed to the organism and who are susceptible. Interventions directed toward this susceptible population, particularly hospitalized patients who receive antibiotics, may be effective. There is moderate evidence on the effectiveness of probiotics to prevent primary CDI, but there are few data to support use in secondary prevention of recurrent CDI. This review discusses the literature available on the use of probiotics to prevent primary and secondary CDI.

The Role of Glutamate Dehydrogenase (GDH) Testing Assay in the Diagnosis of Clostridium difficile Infections: A High Sensitive Screening Test and an Essential Step in the Proposed Laboratory Diagnosis Workflow for Developing Countries like China

The incidence and severity of Clostridium difficile infection (CDI) in North America and Europe has increased significantly since the 2000s. However, CDI is not widely recognized in China and other developing countries due to limited laboratory diagnostic capacity and low awareness. Most published studies on laboratory workflows for CDI diagnosis are from developed countries, and thus may not be suitable for most developing countries. Therefore, an alternative strategy for developing countries is needed. In this study, we evaluated the performance of the Glutamate Dehydrogenase (GDH) test and its associated workflow on 416 fecal specimens from suspected CDI cases. The assay exhibited excellent sensitivity (100.0%) and specificity (92.8%), compared to culture based method, and thus could be a good screening marker for C. difficile but not for indication of toxin production. The VIDAS CDAB assay, which can detect toxin A/B directly from fecal specimens, showed good specificity (99.7%) and positive predictive value (97.2%), but low sensitivity (45.0%) and negative predictive value (88.3%), compared with PCR-based toxin gene detection. Therefore, we propose a practical and efficient GDH test based workflow strategy for the laboratory diagnosis of CDI in developing countries like China. By applying this new workflow, the CDI laboratory diagnosis rate was notably improved in our center, yet the increasing cost was kept at a minimum level. Furthermore, to gain some insights into the genetic population structure of C. difficile isolates from our hospital, we performed MLST and PCR toxin gene typing.

ICU-Onset Clostridium difficile infection in a university hospital in China: a prospective cohort study

A prospective study was conducted to investigate the incidence, clinical profiles and outcome of ICU-onset CDI in a 50-bed medical ICU at a university hospital in China. Stools were collected from patients who developed ICU-onset diarrhea and was screened for tcdA (toxin A gene) and tcdB (toxin B gene) by PCR. CDI cases were compared with the ICU-onset non-CDI diarrhea cases for demographics, comorbidities, potential risk factors, major laboratory findings and outcomes. Stool samples from CDI cases were subjected to C. difficile culture and C. difficile isolates were screened for tcdA, tcdB and the binary toxin genes (cdtA and cdtB) using multiplex PCR. Strain typing of toxigenic C. difficile isolates was performed using multilocus sequence typing. There were 1,277 patients in the ICU during the study period and 124 (9.7%) developed ICU-onset diarrhea, of which 31 patients had CDI. The incidence of ICU-onset CDI was 25.2 cases per 10,000 ICU days. ICU-onset CDI cases had similar features with ICU-onset non-CDI diarrhea cases including the use of proton pump inhibitors and antibacterial agents. The crude mortality rate of ICU-onset CDI was 22.6%, but the attributable mortality rate of ICU-onset CDI was only 3.2% here. Toxigenic C. difficile isolates were recovered from 28 out of the 31 patients with CDI. cdtA and cdtB were found in two strains. Seventeen STs including 11 new STs were identified. All of the 11 new STs were single-locus variants of known STs and the 17 STs identified here could be clustered into 3 clades. The incidence of ICU-onset CDI here is similar to those in Europe and North America, suggesting that CDI is likely to be a common problem in China. Toxigenic C. difficile here belonged to a variety of STs, which may represent a significant clonal expansion rather than the true clonal diversity.

Overview of Clostridium difficile infection: implications for China

The incidence and severity of Clostridium difficile infection (CDI) have dramatically increased in the Western world in recent years. In contrast, CDI is rarely reported in China, possibly due to under-diagnosis. This article briefly summarizes CDI incidence, management and preventive strategies. The authors intend to raise awareness of this disease among Chinese physicians and health workers, in order to minimize the medical and economic burden of a potential epidemic in the future.

Molecular epidemiology of Clostridium difficile infection in a major chinese hospital: an underrecognized problem in Asia?

Clostridium difficile infection is almost unrecognized in mainland China. We have undertaken a study in a large Chinese teaching hospital in Changsha, Hunan, China, to identify cases of C. difficile, record patient characteristics, and define the molecular epidemiology with respect to ribotype distribution and cross-infection. Between April 2009 and February 2010, we examined fecal samples from 70 hospitalized patients with diarrhea who were receiving or had received antibiotics within the previous 6 weeks. Clinical information was collected and the samples were cultured for C. difficile retrospectively. Isolates were ribotyped, and multiple-locus variable-number tandem-repeat assay (MLVA) subtyping was performed on clusters of the same ribotype. The mean age of patients from whom C. difficile was cultured was 58 years, with only 4/21 patients aged >65 years. All patients, with a single exception, had received a third-generation cephalosporin and/or a quinolone antibiotic. Twenty-one isolates of C. difficile were recovered, and seven different ribotypes were identified, the dominant types being 017 (48%), 046 (14%), and 012 (14%). We identified two clusters of cross-infection with indistinguishable isolates of ribotype 017, with evidence of spread both within and between wards. We have identified C. difficile as a possibly significant problem, with cross-infection and a distinct ribotype distribution, in a large Chinese hospital. C. difficile may be underrecognized in China, and further epidemiological studies across the country together with the introduction of routine diagnostic testing are needed to ascertain the size of this potentially significant problem.

Potent monoclonal antibodies against Clostridium difficile toxin A elicited by DNA immunization

Recent studies have demonstrated that DNA immunization is effective in eliciting antigen-specific antibody responses against a wide range of infectious disease targets. The polyclonal antibodies elicited by DNA vaccination exhibit high sensitivity to conformational epitopes and high avidity. However, there have been limited reports in literature on the production of monoclonal antibodies (mAb) by DNA immunization. Here, by using Clostridium difficile (C. diff) toxin A as a model antigen, we demonstrated that DNA immunization was effective in producing a panel of mAb that are protective against toxin A challenge and can also be used as sensitive reagents to detect toxin A from various testing samples. The immunoglobulin (Ig) gene usage for such mAb was also investigated. Further studies should be conducted to fully establish DNA immunization as a unique platform to produce mAb in various hosts.

Epidemiology of Clostridium difficile infection in Asia

While Clostridium difficile infection (CDI) has come to prominence as major epidemics have occurred in North America and Europe over the recent decade, awareness and surveillance of CDI in Asia have remained poor. Limited studies performed throughout Asia indicate that CDI is also a significant nosocomial pathogen in this region, but the true prevalence of CDI remains unknown. A lack of regulated antibiotic use in many Asian countries suggests that the prevalence of CDI may be comparatively high. Molecular studies indicate that ribotypes 027 and 078, which have caused significant outbreaks in other regions of the world, are rare in Asia. However, variant toxin A-negative/toxin B-positive strains of ribotype 017 have caused epidemics across several Asian countries. Ribotype smz/018 has caused widespread disease across Japan over the last decade and more recently emerged in Korea. This review summarises current knowledge on CDI in Asian countries.

Protective antibody responses against Clostridium difficile elicited by a DNA vaccine expressing the enzymatic domain of toxin B

A DNA vaccination approach was used in the current study to screen for the immunogenicity of different fragments of toxin A and toxin B from Clostridium difficile. With this approach, protein antigens do not need to be produced in vitro and the immunogenicity of candidate C. difficile antigens can be identified directly in animals. Codon optimized toxin gene fragments were individually cloned into the DNA vaccine vector and tested in mice and rabbits for their ability to elicit C. difficile toxin-specific antibody responses. Only a subset of the C. difficile toxin fragments, including the C-terminal receptor binding domain of toxin A and a novel N-terminal enzymatic domain of toxin B, were able to elicit protective antibody responses as determined by protection of target cells in a cytotoxicity assay or by preventing death of mice in a passive antibody protection study. Significantly, antibodies elicited by the novel N-terminus of the toxin B DNA vaccine were able to increase the level of protection when used in combination with anti-toxin A antibodies in a toxin challenge model in mice.

Milk-borne infections. An analysis of their potential effect on the milk industry

In developed countries such as the United States of America, foodborne illnesses account for 48 million infections per year. Developing countries such as India face greater simultaneous challenges particularly since incorrect processing or storage of dairy products can represent a transmission hazard for a large number of pathogens and can be responsible for outbreaks of brucellosis, listeriosis, tuberculosis, etc. It is important to recognize the types of germs which can be transmitted through insufficient thermal preparation of milk or milk products or through post-pasteurization contamination, in order to successfully avoid transmission of milk-borne infections.

Safety evaluation of cephalosporins based on utilization and adverse drug events: analysis of two databases in China

OBJECTIVE

The aim of this study is to evaluate the safety of cephalosporins, based on utilization and adverse drug events (ADEs).

METHODS

This is a retrospective study using data on cephalosporins, obtained from Yangtze River hospital drug information and the Wuhan adverse drug reactions monitoring center database, from January 2009 to December 2010, in 30 hospitals in China.

RESULTS

22/44 (55%) cephalosporins were third-generation, which accounted for more than 50% of total expenditure. The top five cephalosporins (sorted by their defined daily doses) were cefodizime sodium, cefoperazone/sulbactam sodium, cefaclor, cefixime and cefmenoxime hydrochloride, which were used 182.93, 110.63, 109.09, 101.47 and 100.05 defined daily dose per 10,000 days, respectively. Third-generation cephalosporins were responsible for 747/1337 ADEs (55.87%). In particular, 208 episodes (15.56%) were associated with ceftriaxone. The most frequently reported damages were involved in the skin and its appendages (967, 68.92%). 603 (45.10%) were identified as definite in causality evaluation. Cefaclor was found to be safer than other cephalosporins, whereas ceftriaxone was found to be less safe.

CONCLUSION

This retrospective evaluation demonstrated that overused and misused cephalosporins caused a relatively high incidence of ADEs. Therefore, surveillance should be strengthened successfully to optimize the rational use of cephalosporins.