Prospective study of oral teicoplanin versus oral vancomycin for therapy of pseudomembranous colitis and Clostridium difficile-associated diarrhea

Clostridioides difficile infection: history, epidemiology, risk factors, prevention, clinical manifestations, treatment, and future options

SUMMARYClostridioides difficile infection (CDI) is one of the major issues in nosocomial infections. This bacterium is constantly evolving and poses complex challenges for clinicians, often encountered in real-life scenarios. In the face of CDI, we are increasingly equipped with new therapeutic strategies, such as monoclonal antibodies and live biotherapeutic products, which need to be thoroughly understood to fully harness their benefits. Moreover, interesting options are currently under study for the future, including bacteriophages, vaccines, and antibiotic inhibitors. Surveillance and prevention strategies continue to play a pivotal role in limiting the spread of the infection. In this review, we aim to provide the reader with a comprehensive overview of epidemiological aspects, predisposing factors, clinical manifestations, diagnostic tools, and current and future prophylactic and therapeutic options for C. difficile infection.

In-line treatments and clinical initiatives to fight against COVID-19 outbreak

In December 2019, when the whole world is waiting for Christmas and New Year, the physicians of Wuhan, China, are astounded by clusters of patients suffering from pneumonia from unknown causes. The pathogen isolated from the respiratory epithelium of the patients is similar to previously known coronaviruses with some distinct features. The disease was initially called nCoV-2019 or SARS-nCoV-2 and later termed as COVID-19 by WHO. The infection is rapidly propagating from the day of emergence, spread throughout the globe and now became a pandemic which challenged the competencies of developed nations in terms of health care management. As per WHO report, 216 countries are affected with SARS-CoV-19 by August 5, 2020 with 18, 142, 718 confirmed cases and 691,013 deaths reports. Such huge mortality and morbidity rates are truly threatening and calls for some aggressive and effective measures to slow down the disease transmission. The scientists are constantly engaged in finding a potential solution to diagnose and treat the pandemic. Various FDA approved drugs with the previous history of antiviral potency are repurposed for COVID-19 treatment. Different drugs and vaccines are under clinical trials and some rapid and effective diagnostic tools are also under development. In this review, we have highlighted the current epidemiology through infographics, disease transmission and progression, clinical features and diagnosis and possible therapeutic approaches for COVID-19. The article mainly focused on the development and possible application of various FDA approved drugs, including chloroquine, remdesivir, favipiravir, nefamostate mesylate, penciclovir, nitazoxanide, ribavirin etc., vaccines under development and various registered clinical trials exploring different therapeutic measures for the treatment of COVID-19. This information will definitely help the researchers to understand the in-line scientific progress by various clinical agencies and regulatory bodies against COVID-19.

Danish national guideline for the treatment of Clostridioides difficile infection and use of faecal microbiota transplantation (FMT)

Aim: This Danish national guideline describes the treatment of adult patients with Clostridioides (formerly Clostridium) difficile (CD) infection and the use of faecal microbiota transplantation (FMT). It suggests minimum standard for implementing an FMT service.Method: Four scientific societies appointed members for a working group which conducted a systematic literature review and agreed on the text and recommendations. All clinical recommendations were evalluated for evidence level and grade of recommendation.Results: In CD infection, the use of marketed and experimental antibiotics as well as microbiota-based therapies including FMT are described. An algorithm for evaluating treatment effect is suggested. The organisation of FMT, donor recruitment and screening, laboratory preparation, clinical application and follow-up are described.Conclusion: Updated evidence for the treatment of CD infection and the use of FMT is provided.

Teicoplanin Suppresses Vegetative Clostridioides difficile and Spore Outgrowth

In recent decades, the incidence of Clostridioides difficile infection (CDI) has remained high in both community and health-care settings. With the increasing rate of treatment failures and its ability to form spores, an alternative treatment for CDI has become a global priority. We used the microdilution assay to determine minimal inhibitory concentrations (MICs) of vancomycin and teicoplanin against 30 distinct C. difficile strains isolated from various host origins. We also examined the effect of drugs on spore germination and outgrowth by following the development of OD₆₀₀. Finally, we confirmed the spore germination and cell stages by microscopy. We showed that teicoplanin exhibited lower MICs compared to vancomycin in all tested isolates. MICs of teicoplanin ranged from 0.03-0.25 µg/mL, while vancomycin ranged from 0.5-4 µg/mL. Exposure of C. difficile spores to broth supplemented with various concentrations of antimicrobial agents did not affect the initiation of germination, but the outgrowth to vegetative cells was inhibited by all test compounds. This finding was concordant with aberrant vegetative cells after antibiotic treatment observed by light microscopy. This work highlights the efficiency of teicoplanin for treatment of C. difficile through prevention of vegetative cell outgrowth.

[Updated review of Clostridium difficile infection in elderly]

Clostridium difficile infection is the most common cause of health care-associated diarrhoea, and its incidence increases with age. Clinical challenges, risk of resistance to treatment, risk of recurrence, and treatment responses are different in elderly. The aim of this review is to discuss the updated epidemiology, pathophysiology, diagnosis, and therapeutic management of C. difficile infection in elderly with the available data.

Recommendations for the diagnosis and treatment of Clostridioides difficile infection: An official clinical practice guideline of the Spanish Society of Chemotherapy (SEQ), Spanish Society of Internal Medicine (SEMI) and the working group of Postoperative Infection of the Spanish Society of Anesthesia and Reanimation (SEDAR)

This document gathers the opinion of a multidisciplinary forum of experts on different aspects of the diagnosis and treatment of Clostridioides difficile infection (CDI) in Spain. It has been structured around a series of questions that the attendees considered relevant and in which a consensus opinion was reached. The main messages were as follows: CDI should be suspected in patients older than 2 years of age in the presence of diarrhea, paralytic ileus and unexplained leukocytosis, even in the absence of classical risk factors. With a few exceptions, a single stool sample is sufficient for diagnosis, which can be sent to the laboratory with or without transportation media for enteropathogenic bacteria. In the absence of diarrhoea, rectal swabs may be valid. The microbiology laboratory should include C. difficile among the pathogens routinely searched in patients with diarrhoea. Laboratory tests in different order and sequence schemes include GDH detection, presence of toxins, molecular tests and toxigenic culture. Immediate determination of sensitivity to drugs such as vancomycin, metronidazole or fidaxomycin is not required. The evolution of toxin persistence is not a suitable test for follow up. Laboratory diagnosis of CDI should be rapid and results reported and interpreted to clinicians immediately. In addition to the basic support of all diarrheic episodes, CDI treatment requires the suppression of antiperistaltic agents, proton pump inhibitors and antibiotics, where possible. Oral vancomycin and fidaxomycin are the antibacterials of choice in treatment, intravenous metronidazole being restricted for patients in whom the presence of the above drugs in the intestinal lumen cannot be assured. Fecal material transplantation is the treatment of choice for patients with multiple recurrences but uncertainties persist regarding its standardization and safety. Bezlotoxumab is a monoclonal antibody to C. difficile toxin B that should be administered to patients at high risk of recurrence. Surgery is becoming less and less necessary and prevention with vaccines is under research. Probiotics have so far not been shown to be therapeutically or preventively effective. The therapeutic strategy should be based, rather than on the number of episodes, on the severity of the episodes and on their potential to recur. Some data point to the efficacy of oral vancomycin prophylaxis in patients who reccur CDI when systemic antibiotics are required again.

Recommendations and guidelines for the treatment of Clostridioides difficile infection in Taiwan

Clostridioides difficile infection (CDI) is a major enteric disease associated with antibiotic use and a leading cause of hospital-acquired infections worldwide. This is the first guideline for treatment of CDI in Taiwan, aiming to optimize medical care for patients with CDI. The target audience of this document includes all healthcare personnel who are involved in the medical care of patients with CDI. The 2018 Guidelines Recommendations for Evidence-based Antimicrobial agents use in Taiwan (GREAT) working group was formed, comprising of infectious disease specialists from 13 medical centers in Taiwan, to review the evidence and draft recommendations using the grading of recommendations assessment, development, and evaluation (GRADE) methodology. A nationwide expert panel reviewed the recommendations during a consensus meeting in March 2019. The recommendation is endorsed by the Infectious Diseases Society of Taiwan (IDST). This guideline describes the epidemiology and risk factors of CDI, and provides recommendations for treatment of CDI in both adults and children. Recommendations for treatment of the first episode of CDI, first recurrence, second and subsequent recurrences of CDI, severe CDI, fulminant CDI, and pediatric CDI are provided.

Prevention of recurrent Clostridioides difficile infection: A systematic review of randomized controlled trials

Recurrent Clostridioides (formerly Clostridium) difficile infection (rCDI) is common, and patients who have had one recurrence are more likely to have multiple recurrences. Frequent recurrences have been associated with increased morbidity and mortality, high healthcare costs, and lower quality of life. In this review, we compare the efficacy of interventions designed to prevent rCDI. We performed a systematic review of the English literature, including randomized controlled trials (RCTs) that evaluated rCDI as an outcome. Studies were included irrespective of patient demographics, disease severity, type of intervention, comparator used, or time-point of outcome evaluation. We performed a comprehensive literature search with the assistance of a research librarian. Two reviewers independently extracted data and assessed risk of bias. Our search yielded 38 RCTs (8,102 participants). Nineteen RCTs (3,743 subjects) evaluated antibiotics, eight fecal microbiota transplantation (FMT) (582 subjects), three monoclonal antibodies (MAbs) (2,805 subjects), and eight probiotics, prebiotics, or non-antibiotic polymers (972 subjects). The antibiotic and FMT therapies that demonstrated efficacy in rCDI prevention included: fidaxomicin (when compared to a ten-day vancomycin course) and FMT administered by nasogastric tube (when compared to a fourteen-day vancomycin course and a fourteen-day vancomycin course plus bowel lavage). Actoxumab (MAb against C. difficile toxin A; CDA1) plus bezlotoxumab (MAb against C. difficile toxin B; CDB1) in combination or bezlotoxumab alone appeared to be more effective in preventing rCDI compared to actoxumab alone. Of the prebiotics, probiotics, and nonantibiotic polymers, oligofructose, Saccharomyces boulardii, and the nontoxigenic C. difficile strain M3 were the most efficacious for rCDI prevention. Thirty-eight RCTs (>8,000 participants) evaluating treatment modalities for CDI were examined for efficacy in prevention of rCDI. Several CDI-specific antibiotics, FMT modalities, monoclonal antibodies, and various prebiotics and probiotics demonstrated a reduction in risk of rCDI with the greatest risk reduction observed with FMT and monoclonal antibody therapy. It is notable that the comparators in these studies were very different from one another and the relative risk reduction of rCDI may not be directly comparable from one study to the next.

Comparison of three current Clostridioides difficile infection guidelines: IDSA/SHEA, ESCMID, and ACG guidelines

PURPOSE

Clostridioides difficile infection (CDI) is a widely recognized condition associated with comorbidity and decreased patient quality of life. Certain professional medical organizations develop clinical practice guidelines for major diseases. This is done in an effort to streamline the universal clinical practice and ensure that a more accurate diagnosis and better treatments are offered to respective patients for optimal outcomes. However, as new data evolve, constant update of these guidelines becomes essential. While these guidelines provide up-to-date recommendations, they are not published around the same time; thus, their recommendations may vary depending on evidence available prior to guidelines preparation and publication.

METHODS

Recommendations and corresponding justifications from three major CDI guidelines between 2013 and 2017 were pooled and compared, and notable differences were highlighted while providing an insight and a final recommendation from a clinical standpoint.

RESULTS

Most recommendations were consistent among all three guidelines. One notable difference was in the specification of candidates for CDI diagnosis, where it would be recommended to mainly test patients with three or more diarrheal episodes over 24 h, if they had no other clear reason for the diarrhea. Another conflicting point was regarding the treatment of non-severe CDI where vancomycin can be considered for older or sicker patients; however, metronidazole still remains a reasonable option based on recent data, some of which were not cited in the most recent guidelines of IDSA/SHEA.

CONCLUSION

Overall, it is prudent to follow these guidelines with critical appraisal to fulfill the goal of achieving optimum patient outcomes.

Guidelines for Antibiotic Prescription in Intensive Care Unit

How to cite this article: Khilnani GC, Zirpe K, Hadda V, Mehta Y, Madan K, Kulkarni A, Mohan A, Dixit S, Guleria R, Bhattacharya P. Guidelines for Antibiotic Prescription in Intensive Care Unit. Indian Journal of Critical Care Medicine 2019;23 (Suppl 1):1-63.

Management of adult Clostridium difficile digestive contaminations: a literature review

Clostridium difficile infections (CDI) dramatically increased during the last decade and cause a major public health problem. Current treatments are limited by the high disease recurrence rate, severity of clinical forms, disruption of the gut microbiota, and colonization by vancomycin-resistant enterococci (VRE). In this review, we resumed current treatment options from official recommendation to promising alternatives available in the management of adult CDI, with regard to severity and recurring or non-recurring character of the infection. Vancomycin remains the first-line antibiotic in the management of mild to severe CDI. The use of metronidazole is discussed following the latest US recommendations that replaced it by fidaxomicin as first-line treatment of an initial episode of non-severe CDI. Fidaxomicin, the most recent antibiotic approved for CDI in adults, has several advantages compared to vancomycin and metronidazole, but its efficacy seems limited in cases of multiple recurrences. Innovative therapies such as fecal microbiota transplantation (FMT) and antitoxin antibodies were developed to limit the occurrence of recurrence of CDI. Research is therefore very active, and new antibiotics are being studied as surotomycin, cadazolid, and rinidazole.

Enhanced Efficacy of High Dose Oral Vancomycin Therapy in Clostridium difficile Diarrhea for Hospitalized Adults Not Responsive to Conventional Oral Vancomycin Therapy: Antibiotic Stewardship Implications

Current therapy of Clostridium difficile diarrhea (CDD) is problematic. Optimal treatment for CDD remains oral vancomycin, but there is little data on oral vancomycin dosing regimens. The objective of this C. difficile diarrhea study was to compare the efficacy of "high dose" vancomycin, 500 mg (PO) q6h, as sole treatment and in those who after 72 h failed to respond to conventional doses of oral vancomycin, 125-250 mg (PO) q6h. Hospitalized adults with CDD were evaluated by various oral vancomycin regimens, i.e., a conventional dose group (125-250 mg (PO) q6h), a "high dose escalation" dose group (250 mg → 500 mg (PO) q6h), and a "high dose" group (500 mg (PO) q6h). Oral vancomycin treatment groups were compared by time to improvement, i.e., decrease in >50% of watery stools/day and duration of therapy. The high dose escalation and high dose oral vancomycin groups showed the most rapid resolution of diarrhea. There was marked decrease in stools/day after "high dose" vancomycin escalation from conventional dosing, i.e., 250 mg (PO) q6h → 500 mg (PO) q6h. This study demonstrated that "high dose" escalation or initial high dose oral vancomycin, i.e., 500 mg (PO) q6h was the most efficacious regimen for CDD.

Antibiotic treatment for Clostridium difficile-associated diarrhoea in adults

BACKGROUND

Clostridium difficile (C. difficile) is recognized as a frequent cause of antibiotic-associated diarrhoea and colitis. This review is an update of a previously published Cochrane review.

OBJECTIVES

The aim of this review is to investigate the efficacy and safety of antibiotic therapy for C. difficile-associated diarrhoea (CDAD), or C. difficile infection (CDI), being synonymous terms.

SEARCH METHODS

We searched MEDLINE, EMBASE, CENTRAL and the Cochrane IBD Group Specialized Trials Register from inception to 26 January 2017. We also searched clinicaltrials.gov and clinicaltrialsregister.eu for ongoing trials.

SELECTION CRITERIA

Only randomised controlled trials assessing antibiotic treatment for CDI were included in the review.

DATA COLLECTION AND ANALYSIS

Three authors independently assessed abstracts and full text articles for inclusion and extracted data. The risk of bias was independently rated by two authors. For dichotomous outcomes, we calculated the risk ratio (RR) and corresponding 95% confidence interval (95% CI). We pooled data using a fixed-effect model, except where significant heterogeneity was detected, at which time a random-effects model was used. The following outcomes were sought: sustained symptomatic cure (defined as initial symptomatic response and no recurrence of CDI), sustained bacteriologic cure, adverse reactions to the intervention, death and cost.

MAIN RESULTS

Twenty-two studies (3215 participants) were included. The majority of studies enrolled patients with mild to moderate CDI who could tolerate oral antibiotics. Sixteen of the included studies excluded patients with severe CDI and few patients with severe CDI were included in the other six studies. Twelve different antibiotics were investigated: vancomycin, metronidazole, fusidic acid, nitazoxanide, teicoplanin, rifampin, rifaximin, bacitracin, cadazolid, LFF517, surotomycin and fidaxomicin. Most of the studies were active comparator studies comparing vancomycin with other antibiotics. One small study compared vancomycin to placebo. There were no other studies that compared antibiotic treatment to a placebo or a 'no treatment' control group. The risk of bias was rated as high for 17 of 22 included studies. Vancomycin was found to be more effective than metronidazole for achieving symptomatic cure. Seventy-two per cent (318/444) of metronidazole patients achieved symptomatic cure compared to 79% (339/428) of vancomycin patients (RR 0.90, 95% CI 0.84 to 0.97; moderate quality evidence). Fidaxomicin was found to be more effective than vancomycin for achieving symptomatic cure. Seventy-one per cent (407/572) of fidaxomicin patients achieved symptomatic cure compared to 61% (361/592) of vancomycin patients (RR 1.17, 95% CI 1.04 to 1.31; moderate quality evidence). Teicoplanin may be more effective than vancomycin for achieving a symptomatic cure. Eightly-seven per cent (48/55) of teicoplanin patients achieved symptomatic cure compared to 73% (40/55) of vancomycin patients (RR 1.21, 95% CI 1.00 to 1.46; very low quality evidence). For other comparisons including the one placebo-controlled study the quality of evidence was low or very low due to imprecision and in many cases high risk of bias because of attrition and lack of blinding. One hundred and forty deaths were reported in the studies, all of which were attributed by study authors to the co-morbidities of the participants that lead to acquiring CDI. Although many other adverse events were reported during therapy, these were attributed to the participants' co-morbidities. The only adverse events directly attributed to study medication were rare nausea and transient elevation of liver enzymes. Recent cost data (July 2016) for a 10 day course of treatment shows that metronidazole 500 mg is the least expensive antibiotic with a cost of USD 13 (Health Warehouse). Vancomycin 125 mg costs USD 1779 (Walgreens for 56 tablets) compared to fidaxomicin 200 mg at USD 3453.83 or more (Optimer Pharmaceuticals) and teicoplanin at approximately USD 83.67 (GBP 71.40, British National Formulary).

AUTHORS' CONCLUSIONS

No firm conclusions can be drawn regarding the efficacy of antibiotic treatment in severe CDI as most studies excluded patients with severe disease. The lack of any 'no treatment' control studies does not allow for any conclusions regarding the need for antibiotic treatment in patients with mild CDI beyond withdrawal of the initiating antibiotic. Nonetheless, moderate quality evidence suggests that vancomycin is superior to metronidazole and fidaxomicin is superior to vancomycin. The differences in effectiveness between these antibiotics were not too large and the advantage of metronidazole is its far lower cost compared to the other two antibiotics. The quality of evidence for teicoplanin is very low. Adequately powered studies are needed to determine if teicoplanin performs as well as the other antibiotics. A trial comparing the two cheapest antibiotics, metronidazole and teicoplanin, would be of interest.

A Review of Experimental and Off-Label Therapies for Clostridium difficile Infection

In spite of increased awareness and the efforts taken to optimize Clostridium difficile infection (CDI) management, with the limited number of currently available antibiotics for C. difficile the halt of this increasing epidemic remains out of reach. There are, however, close to 80 alternative treatment methods with controversial anti-clostridial efficacy or in experimental phase today. Indeed, some of these therapies are expected to become acknowledged members of the recommended anti-CDI arsenal within the next few years. None of these alternative treatment methods can respond in itself to all the major challenges of CDI management, which are primary prophylaxis in the susceptible population, clinical cure of severe cases, prevention of recurrences, and forestallment of asymptomatic C. difficile carriage and in-hospital spread. Yet, the greater the variety of treatment choices on hand, the better combination strategies can be developed to reach these goals in the future. The aim of this article is to provide a comprehensive summary of these experimental and currently off-label therapeutic options.

Australasian Society of Infectious Diseases updated guidelines for the management of Clostridium difficile infection in adults and children in Australia and New Zealand

The incidence of Clostridium difficile infection (CDI) continues to rise, whilst treatment remains problematic due to recurrent, refractory and potentially severe nature of disease. The treatment of C. difficile is a challenge for community and hospital-based clinicians. With the advent of an expanding therapeutic arsenal against C. difficile since the last published Australasian guidelines, an update on CDI treatment recommendations for Australasian clinicians was required. On behalf of the Australasian Society of Infectious Diseases, we present the updated guidelines for the management of CDI in adults and children.

Controversies Around Epidemiology, Diagnosis and Treatment of Clostridium difficile Infection

Clostridium difficile infection is a major public health problem. However, in recent years the epidemiology, risk factors, diagnosis, and treatment of C. difficile infection have undergone a significant change. The incidence of C. difficile has increased, not only in the healthcare sector but also in the community. Hospital-acquired infection and community-acquired disease have different risk factors, with the latter occurring in children and younger individuals without a history of antibiotic use or previous infections. From a clinician's perspective, a quick efficient diagnosis is required for patient treatment; however, the old method of using enzyme immunoassays is insensitive and not very specific. Recent literature around diagnostic testing for C. difficile infection suggests using PCR or a two-step algorithm to improve sensitivity and specificity. More failures and recurrence with metronidazole have led to treatment algorithms suggesting its use for mild infections and switching to vancomycin if there is no clinical improvement. Alternatively, if signs and symptoms suggest severe infection, then oral vancomycin is recommended as a first-line agent. The addition of a new but costly agent, fidaxomicin, has seen some disparity between the European and North American guidelines with regard to when it should be used. Lastly, rapid developments and good results with fecal microbial transplantation have also left clinicians wondering about its place in therapy. This article reviews the literature around some of the recent controversies in the field of C. difficile infection.

Treatment of Clostridium difficile infection in mice with vancomycin alone is as effective as treatment with vancomycin and metronidazole in combination

Objective

Clostridium difficile is a major cause of nosocomial infectious diarrhoea. Treatment of C. difficile infection (CDI) depends on disease severity. A combination of vancomycin and metronidazole is often recommended in severe cases. The aim of this study was to examine, in a murine model of CDI, if mice treated with a combination of vancomycin and metronidazole had a better clinical outcome than mice treated with vancomycin or metronidazole alone.

Design

C57BL/6J mice pretreated with an antimicrobial mixture were challenged with C. difficile VPI 10463 or phosphate-buffered saline by oral gavage. After the challenge, the mice were treated with placebo, vancomycin, metronidazole or a combination of vancomycin and metronidazole for 10 days. The mice were monitored for 20 days with weight and a clinical score. Stool samples were examined for C. difficile spore load and presence of C. difficile toxins.

Results

None of the mice in the vancomycin-treated group died during the treatment phase compared to a mortality of 17%, 33% and 55% in the combination, metronidazole and infected control group, respectively. Mice treated with vancomycin alone or in combination with metronidazole recovered from CDI faster than mice treated with metronidazole alone. However, after discontinuation of treatment, vancomycin-treated and combination-treated mice succumbed to clinical and bacteriological relapse.

Conclusions

Mice treated with vancomycin alone had a better clinical outcome in the treatment phase of CDI than mice treated with metronidazole alone. A combination of vancomycin and metronidazole did not improve the clinical outcome when compared to treatment with vancomycin alone.

Trial registration number

The trial registration number from the Danish Experimental Animal Inspectorate is J number 2012-15-2934-00422.

Rational Therapy of Clostridium difficile Infections

Background

Clostridium difficile infections (CDI) are increasingly important in patients with antibiotic treatments, ranging from mild, self-limiting to severe, life-threatening disease. Currently, diagnostic algorithms and treatment guidelines are being adapted to novel tests and therapeutic options for recurrent CDI.

Methods

A systematic literature search using the terms ‘Clostridium difficile’ and ‘treatment’ was carried out. Current guidelines are being discussed from a clinical point of view.

Results

State-of-the-art diagnostics for C. difficile diagnosis rely on the patient's history, clinical symptoms, and laboratory examination of stool. Recommendations are in favour of glutamate dehydrogenase (GDH) screening tests and confirmatory detection of C. difficile toxin genes (polymerase chain reaction (PCR)). Therapeutic strategies depend on disease severity (mild vs. severe) and endorse metronidazole and vancomycin as well as fidaxomycin for recurrent disease. In very severe cases, surgical therapy is recommended. For relapsing diseases, faecal transfer is considered as a therapeutic option if available.

Conclusion

Current guidelines have been adapted to new pathways in diagnosing CDI and have included statements on novel therapeutic options such as fidaxomycin and faecal transplant for recurrent disease. Depending on the severity of the disease, standard therapy with either metronidazole or vancomycin is recommended.

Clostridium difficile infection: current, forgotten and emerging treatment options

Clostridium difficile infection (CDI) has increased in incidence and severity, and is now among the most common nosocomial infections. Several agents are available for the initial treatment of CDI, some of which are rarely used, and none of which is clearly superior for initial clinical cure. Fidaxomicin appears to offer a benefit in terms of preventing recurrent disease, although the cost-benefit ratio is debated. Recurrent CDI is a major challenge, occurring after 15-30% of initial episodes. The treatment of recurrent CDI is difficult, with sparse evidence available to support any particular agent. Fecal microbiota therapy, also known as 'stool transplantation', appears to be highly effective, although availability is currently limited, and the regulatory environment is in flux. Synthetic stool products and an orally available fecal microbiota therapy product are both under investigation, which may address the problem of availability. As with most infectious diseases, an effective vaccine would be a welcome addition to our armamentarium, but none is currently available.

Extrachromosomal and integrated genetic elements in Clostridium difficile

Clostridium difficile is a major nosocomial pathogen, causing gastrointestinal disease in patients undergoing antibiotic therapy. This bacterium contains many extrachromosomal and integrated genetic elements, with recent genomic work giving new insights into their variability and distribution. This review summarises research conducted in this area over the last 30 years and includes a discussion on the functional contributions of these elements to host cell phenotypes, as well as encompassing recent genome sequencing studies that have contributed to our understanding of their evolution and dissemination. Importantly, we also include a review of antibiotic resistance determinants associated with mobile genetic elements since antibiotic use and the spread of antibiotic resistance are currently of significant global clinical importance.

European Society of Clinical Microbiology and Infectious Diseases: update of the treatment guidance document for Clostridium difficile infection

In 2009 the first European Society of Clinical Microbiology and Infection (ESCMID) treatment guidance document for Clostridium difficile infection (CDI) was published. The guideline has been applied widely in clinical practice. In this document an update and review on the comparative effectiveness of the currently available treatment modalities of CDI is given, thereby providing evidence-based recommendations on this issue. A computerized literature search was carried out to investigate randomized and non-randomized trials investigating the effect of an intervention on the clinical outcome of CDI. 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 ESCMID and an international team of experts from 11 European countries supported the process. To improve clinical guidance in the treatment of CDI, recommendations are specified for various patient groups, e.g. initial non-severe disease, severe CDI, first recurrence or risk for recurrent disease, multiple recurrences and treatment of CDI when oral administration is not possible. Treatment options that are reviewed include: antibiotics, toxin-binding resins and polymers, immunotherapy, probiotics, and faecal or bacterial intestinal transplantation. Except for very mild CDI that is clearly induced by antibiotic usage antibiotic treatment is advised. The main antibiotics that are recommended are metronidazole, vancomycin and fidaxomicin. Faecal transplantation is strongly recommended for multiple recurrent CDI. In case of perforation of the colon and/or systemic inflammation and deteriorating clinical condition despite antibiotic therapy, total abdominal colectomy or diverting loop ileostomy combined with colonic lavage is recommended.

The host immune response to Clostridium difficile infection

Clostridium difficile infection (CDI) is the most common infectious cause of healthcare-acquired diarrhoea. Outcomes of C. difficile colonization are varied, from asymptomatic carriage to fulminant colitis and death, due in part to the interplay between the pathogenic virulence factors of the bacterium and the counteractive immune responses of the host. Secreted toxins A and B are the major virulence factors of C. difficile and induce a profound inflammatory response by intoxicating intestinal epithelial cells causing proinflammatory cytokine release. Host cell necrosis, vascular permeability and neutrophil infiltration lead to an elevated white cell count, profuse diarrhoea and in severe cases, dehydration, hypoalbuminaemia and toxic megacolon. Other bacterial virulence factors, including surface layer proteins and flagella proteins, are detected by host cell surface signal molecules that trigger downstream cell-mediated immune pathways. Human studies have identified a role for serum and faecal immunoglobulin levels in protection from disease, but the recent development of a mouse model of CDI has enabled studies into the precise molecular interactions that trigger the immune response during infection. Key effector molecules have been identified that can drive towards a protective anti-inflammatory response or a damaging proinflammatory response. The limitations of current antimicrobial therapies for CDI have led to the development of both active and passive immunotherapies, none of which have, as yet been formally approved for CDI. However, recent advances in our understanding of the molecular basis of host immune protection against CDI may provide an exciting opportunity for novel therapeutic developments in the future.

An agent-based simulation model for Clostridium difficile infection control

BACKGROUND

Control of Clostridium difficile infection (CDI) is an increasingly difficult problem for health care institutions. There are commonly recommended strategies to combat CDI transmission, such as oral vancomycin for CDI treatment, increased hand hygiene with soap and water for health care workers, daily environmental disinfection of infected patient rooms, and contact isolation of diseased patients. However, the efficacy of these strategies, particularly for endemic CDI, has not been well studied. The objective of this research is to develop a valid, agent-based simulation model (ABM) to study C. difficile transmission and control in a midsized hospital.

METHODS

We develop an ABM of a midsized hospital with agents such as patients, health care workers, and visitors. We model the natural progression of CDI in a patient using a Markov chain and the transmission of CDI through agent and environmental interactions. We derive input parameters from aggregate patient data from the 2007-2010 Wisconsin Hospital Association and published medical literature. We define a calibration process, which we use to estimate transition probabilities of the Markov model by comparing simulation results to benchmark values found in published literature.

RESULTS

In a comparison of CDI control strategies implemented individually, routine bleach disinfection of CDI-positive patient rooms provides the largest reduction in nosocomial asymptomatic colonization (21.8%) and nosocomial CDIs (42.8%). Additionally, vancomycin treatment provides the largest reduction in relapse CDIs (41.9%), CDI-related mortalities (68.5%), and total patient length of stay (21.6%).

CONCLUSION

We develop a generalized ABM for CDI control that can be customized and further expanded to specific institutions and/or scenarios. Additionally, we estimate transition probabilities for a Markov model of natural CDI progression in a patient through calibration.

Antimicrobial Agents in Ophthalmology

Many types of antimicrobial agents have been introduced for the treatment of ocular infectious diseases. Some ocular infections have been eradicated such as smallpox, while others have been controlled by public health measures such as trachoma. The resilience of viruses and the tenacity of bacteria have led to the evolution of old diseases and the emergence of new infections. Continuous search for new antimicrobial agents for the treatment of infectious diseases is, therefore, highly desirable.

New infectious agents are discovering the human race, and the ecological changes are exposing mankind to new viruses and bacteria. In addition, air travel and disruption of geographic barriers are leading to new forms of infectious diseases.

In the twentieth century, there was a widespread false optimism that infectious diseases are eradicated by antimicrobial agents. It was soon discovered that many infections require new strategies for the treatment of ocular infections.

The new antimicrobial agents that have been introduced over the past century can be classified into four major categories including (1) antibiotics that inhibit cell wall synthesis and integrity, (2) antibiotics that inhibit and suppress cell membrane functions, (3) antibiotics that interfere the protein synthesis, and (4) antibiotics that modulate nucleic acid synthesis.

The selection of antimicrobial agents for the treatment of ocular infectious diseases is based on the most frequently encountered organisms, the pharmacokinetics of the antibiotics, the dosage required, the ocular penetration, and the cost of therapy. The stumbling blocks to safe and effective antimicrobial therapy in ocular infections include the resistance of the microorganisms, toxicity of the drug, and poor ocular penetration of antimicrobial agents.

[Antimicrobial therapy of Clostridium difficile infection. Systematic review and meta-analysis of the scientific evidence]

INTRODUCTION

Clostridium difficile is the leading cause of antibiotic associated infectious nosocomial diarrhoea. Limited number of new pharmaceutical products have been developed and registered in the past decades for the treatment of Clostridium difficile infection. The available scientific evidence is limited and hardly comparable.

AIM

To analyse the clinical efficacy and safety of metronidazole, vancomycin and fidaxomicin in the therapy of Clostridium difficile infection.

METHODS

Systematic review and meta-analysis of the literature data.

RESULTS

Meta-analysis of literature data showed no significant difference between these antibiotics in clinical cure endpoint (odss ratios: fidaxomicin vs. vancomycin 1.19; vancomycin vs. metronidazol 1.69 and fidaxomicin vs. metronidazol 2.00). However, fidaxomicin therapy was significantly more effective than vancomicin and metronidazol in endpoints of recurrence and global cure (odds ratios: fidaxomicin vs. vancomycin 0.47; vancomycin vs. metronidazol 0.91 és fidaxomicin vs. metronidazol 0.43). There was no significant difference between fidaxomicin, vancomycin and metronidazole in safety endpoints.

CONCLUSIONS

Each antibiotic similarly improved clinical cure. Fidaxomicin was the most effective therapeutic alternative in lowering the rate of recurrent Clostridium difficile infections.

Current state of Clostridium difficile treatment options

Recent reports of reduced response to standard therapies for Clostridium difficile infection (CDI) and the risk for recurrent CDI that is common with all currently available treatment agents have posed a significant challenge to clinicians. Current recommendations include metronidazole for treatment of mild to moderate CDI and vancomycin for severe CDI. Results from small clinical trials suggest that nitazoxanide and teicoplanin may be alternative options to standard therapies, whereas rifaximin has demonstrated success in uncontrolled trials for the management of multiple recurrences. Anecdotal reports have also suggested that tigecycline might be useful as an adjunctive agent for the treatment of severe complicated CDI. Reports of resistance will likely limit the clinical use of fusidic acid and bacitracin and, possibly, rifaximin if resistance to this agent becomes widespread. Treatment of patients with multiple CDI recurrences and those with severe complicated CDI is based on limited clinical evidence, and new treatments or strategies are needed.

Efficacy of fidaxomicin versus vancomycin as therapy for Clostridium difficile infection in individuals taking concomitant antibiotics for other concurrent infections

Concomitant antibiotic (CA) use compromised initial response to Clostridium difficile infection therapy and durability of that response. Fidaxomicin was significantly more effective than vancomycin in achieving clinical cure in the presence of CAs and preventing recurrence regardless of CA use.

Background. Treatment guidelines recommend stopping all implicated antibiotics at the onset of Clostridium difficile infection (CDI), but many individuals have persistent or new infections necessitating the use of concomitant antibiotics (CAs). We used data from 2 phase 3 trials to study effects of CAs on response to fidaxomicin or vancomycin.

Methods. Subjects with CDI were treated for 10 days with fidaxomicin 200 mg every 12 hours or vancomycin 125 mg every 6 hours, assessed for resolution of symptoms, and followed up for an additional 4 weeks for evidence of recurrence. Rates of cure, recurrence, and global cure (cure without recurrence) were determined for subgroups of subjects defined by CA use and treatment group.

Results. CAs were prescribed for 27.5% of subjects during study participation. The use of CAs concurrent with CDI treatment was associated with a lower cure rate (84.4% vs 92.6%; P < .001) and an extended time to resolution of diarrhea (97 vs 54 hours; P < .001). CA use during the follow-up was associated with more recurrences (24.8% vs 17.7%; not significant), and CA administration at any time was associated with a lower global cure rate (65.8% vs 74.7%; P = .005). When subjects received CAs concurrent with CDI treatment, the cure rate was 90.0% for fidaxomicin and 79.4% for vancomycin (P = .04). In subjects receiving CAs during treatment and/or follow-up, treatment with fidaxomicin compared with vancomycin was associated with 12.3% fewer recurrences (16.9% vs 29.2%; P = .048).

Conclusions. Treatment with CAs compromised initial response to CDI therapy and durability of response. Fidaxomicin was significantly more effective than vancomycin in achieving clinical cure in the presence of CA therapy and in preventing recurrence regardless of CA use.

An overview of the diagnosis and management of Clostridium difficile infection

The diagnosis and treatment of Clostridium difficile infection are becoming increasingly complex with the introduction of novel diagnostic techniques and new pharmacologic and nonpharmacologic treatments. The integration of these new approaches with older, established methods is a challenge to individual clinicians and hospital systems. This article provides an overview of the current methods for the diagnosis and treatment of C difficile infection.

Antibiotic treatment for Clostridium difficile-associated diarrhea in adults

BACKGROUND

Clostridium difficile is recognized as a frequent cause of antibiotic-associated diarrhea and colitis.

OBJECTIVES

The aim of this review is to investigate the efficacy of antibiotic therapy for C. difficile-associated diarrhea (CDAD).

SEARCH STRATEGY

MEDLINE (1966 to March 24, 2010), EMBASE (1980 to March 24, 2010), Cochrane Central Register of Controlled Trials and the Cochrane IBD/FBD Review Group Specialized Trials Register were searched using the following search terms: "pseudomembranous colitis and randomized trial"; "Clostridium difficile and randomized trial"; "antibiotic associated diarrhea and randomized trial".

SELECTION CRITERIA

Only randomized, controlled trials assessing antibiotic treatment for CDAD were included in the review. The following outcomes were sought: initial resolution of diarrhea; initial conversion of stool to cytotoxin and/or culture negative; recurrence of diarrhea; recurrence of fecal evidence of CDAD; patient response to cessation of prior antibiotic therapy; emergent surgery; and death.

DATA COLLECTION AND ANALYSIS

Three authors independently assessed abstracts and full text articles for inclusion. The risk of bias was independently rated by two authors. For dichotomous outcomes, relative risks (RR) and 95% confidence intervals (CI) were derived from each study and summary statistics obtained when appropriate, using a fixed effects model, except where significant heterogeneity was detected, at which time a random effects model was used.

MAIN RESULTS

Fifteen studies (total of 1152 participants) with CDAD were included. Nine different antibiotics were investigated: vancomycin, metronidazole, fusidic acid, nitazoxanide, teicoplanin, rifampin, rifaximin, bacitracin and fidaxomicin (OPT-80). Most of the studies were active comparator studies comparing vancomycin with other antibiotics. The risk of bias was rated as high for 12 of 15 included studies. Patients with severe CDAD were often excluded from the included studies. In the only placebo-controlled trial vancomycin was found to be superior to placebo for treatment of CDAD for initial symptomatic cure. Initial symptomatic cure was achieved in 41% of vancomycin patients compared to 4% of placebo patients (1 study; 44 patients; RR 9.00; 95% CI 1.24 to 65.16). Vancomycin was significantly superior to placebo for initial bacteriologic response. Initial bacteriologic response was achieved in 45% of vancomycin patients compared to 4% of placebo patients (1 study; 44 patients; RR 10.00; 95% CI 1.40 to 71.62). The results of this study should be interpreted with caution due to the small number of patients and high risk of bias. No statistically significant differences in efficacy were found between vancomycin and metronidazole, vancomycin and fusidic acid, vancomycin and nitazoxanide, or vancomycin and rifaximin. No statistically significant differences in efficacy were found between metronidazole and nitazoxanide or metronidazole and fusidic acid. Vancomycin was significantly superior to bacitracin for initial bacteriologic response. Initial bacteriologic response was achieved in 48% of vancomycin patients compared to 25% of bacitracin patients (2 studies; 104 patients; RR 0.52; 95% CI 0.31 to 0.86). Teicoplanin, an antibiotic of limited availability and great cost, was significantly superior to vancomycin for initial bacteriologic response and cure. Initial bacteriologic response was achieved in 62% of vancomycin patients compared to 87% of teicoplanin patients (2 studies; 110 patients; RR 1.43; 95% CI 1.14 to 1.81). Bacteriologic cure was achieved in 45% of vancomycin patients compared to 82% of teicoplanin patients (2 studies; 110 patients; RR 1.82; 95% CI 1.19 to 2.78). These results should be interpreted with caution due to the small number of patients and the high risk of bias in the two studies in the pooled analysis. Teicoplanin was significantly superior to metronidazole for initial bacteriologic response. Initial bacteriologic response was achieved in 71% of metronidazole patients compared to 93% of teicoplanin patients (1 study; 59 patients; RR 0.76; 95% CI 0.60 to 0.98). This result should be interpreted with caution due to the small number of patients and high risk of bias in the study. Only one study investigated synergistic antibiotic combination, metronidazole and rifampin, and no advantage was demonstrated for the drug combination. This result should be interpreted with caution due to the small number of patients and high risk of bias in the study. Adverse events including surgery and death occurred infrequently in the included studies. There was a total of 18 deaths among 1152 patients in this systematic review. Among the studies that commented on the cause of mortality the deaths were attributed to underlying disease rather than CDAD or antibiotic treatment. One study reported a partial colectomy after failed CDAD treatment.

AUTHORS' CONCLUSIONS

Current evidence leads to uncertainty whether mild CDAD needs to be treated. The studies provide little evidence for antibiotic treatment of severe CDAD as many studies excluded these patients. Considering the two goals of therapy: improvement of the patient's clinical condition and prevention of spread of C. difficile infection to other patients, one should choose the antibiotic that brings both symptomatic cure and bacteriologic cure. A recommendation to achieve these goals cannot be made because of the small numbers of patients in the included studies and the high risk of bias in these studies, especially related to dropouts. Most of the active comparator studies found no statistically significant difference in efficacy between vancomycin and other antibiotics including metronidazole, fusidic acid, nitazoxanide or rifaximin. Teicoplanin may be an attractive choice but for its limited availability (Teicoplanin is not available in the USA) and great cost relative to the other options. More research of antibiotic treatment and other treatment modalities of CDAD is required.

Treatment of refractory and recurrent Clostridium difficile infection

The incidence of Clostridium difficile infection (CDI) has increased since 2000, with greater numbers of severe cases reported, in part due to the emergence of a hypervirulent strain. Initial therapy with metronidazole is still recommended for mild to moderate CDI, but vancomycin is recommended for first-line therapy of severe CDI. Colectomy could be life-saving for some patients with severe disease that does not respond to maximal medical therapy. Recurrent CDI is a challenge to treat; no single effective therapy currently exists. Treatments include antibiotics, adjunct probiotics, fecal microbiota transplant and immune approaches. This Review discusses the various therapeutic approaches used for the treatment of refractory and recurrent CDI.

Alternative therapies for Clostridium difficile infections

Clostridium difficile infection is a serious condition responsible for significant morbidity and mortality, especially in patients being treated with antimicrobials. Increasing frequency of the infection and hypervirulent C. difficile strains have resulted in more severe disease as well as therapeutic failures with traditional treatment (metronidazole and vancomycin). To review the studies assessing nontraditional therapies for the prevention and treatment of primary or recurrent C. difficile infection, we conducted a literature search of the PubMed-MEDLINE databases (1984-2010). Of the 98 studies identified, 21 met our inclusion criteria. Five clinical trials and one retrospective medical record review evaluated probiotic or prebiotic formulations for the prevention of C. difficile infection. Only one of these studies, which included Lactobacillus casei and L. bulgaricus in the probiotic formulation, showed efficacy. Ten clinical trials evaluated treatment of an initial episode of C. difficile infection (primary treatment) with the anti-microbials fidaxomicin, fusidic acid, rifampin, teicoplanin, and nitazoxanide, as well as the toxin-binding polymer, tolevamer. Only nitazoxanide and teicoplanin demonstrated noninferiority when compared with vancomycin or metronidazole. Four prospective studies and one retrospective study evaluated treatment of relapsing C. difficile infection. Prebiotic formulations for the prevention and treatment of recurrent C. difficile infection have not proved to be clinically warranted. Nitazoxanide, teicoplanin, and fidaxomicin may be considered as alternatives to traditional treatment; however, clinical experience is limited with these agents for this indication. Bacteriotherapy with fecal instillation has demonstrated high clinical cure rates in case studies and in a retrospective study; however, to our knowledge, randomized clinical trials are lacking for this therapeutic approach. As C. difficile infection rates continue to increase and hypervirulent strains continue to emerge, it is important for future clinical studies to assess alternative therapies.

Clostridium difficile: progress and challenges

There is a surge of new interest in C. difficile infection (CDI) reflecting substantial increases in cases and fatalities. The new challenges by this now old pathogen have brought renewed interest in all facets of the disease. Particularly important are the role of fluoroquinolones as inducing agents, the new polymerase chain reaction test to detect toxigenic strains in stools, the important role of the NAP-1 strain, recent evidence favoring oral vancomycin over metronidazole in seriously ill patients, and new guidelines for management.

Teicoplanin versus vancomycin for proven or suspected infection

BACKGROUND

Vancomycin and teicoplanin are commonly used to treat gram-positive infections, particularly those caused by methicillin-resistant Staphylococcus aureus (MRSA). There is uncertainty regarding the effects of teicoplanin compared to vancomycin on kidney function with some previous studies suggesting teicoplanin is less nephrotoxic than vancomycin.

OBJECTIVES

To investigate the efficacy and safety of vancomycin versus teicoplanin in patients with proven or suspected infection.

SEARCH STRATEGY

We searched the Cochrane Renal Group's Specialised Register, CENTRAL, MEDLINE, EMBASE, reference lists of nephrology textbooks, review articles with relevant studies and sent letters seeking information about unpublished or incomplete studies to investigators involved in previous studies.

SELECTION CRITERIA

We searched for randomised controlled trials (RCTs) in any language comparing teicoplanin to vancomycin for patients with proven or suspected infection.

DATA COLLECTION AND ANALYSIS

Two authors independently evaluated methodological quality and extracted data using standardised data extraction forms. Study investigators were contacted for information not available in the original manuscripts. Random effects model was used to estimate the pooled risk ratio (RR) with 95% confidence interval (CI).

MAIN RESULTS

We included 24 studies (2,610 patients) in this review. Teicoplanin reduced the risk of nephrotoxicity compared to vancomycin (RR 0.66, 95% CI 0.48 to 0.90).The effects of teicoplanin or vancomycin were similar for clinical cure (RR 1.03, 95% CI 0.98 to 1.08), microbiological cure (RR 0.98, 95% CI 0.93 to 1.03) and mortality (RR 1.02, 95% CI 0.79 to1.30). Six studies reported no cases of acute kidney injury (AKI) needing dialysis. Adverse events were less frequent with teicoplanin including cutaneous rash (RR 0.57, 95% CI 0.35 to 0.92), red man syndrome (RR 0.21, 95% CI 0.08 to 0.59) and total adverse events (RR 0.73, 95% CI 0.53 to 1.00). A lower risk of nephrotoxicity with teicoplanin was observed in patients either with (RR 0.51, 95% CI 0.30 to 0.88) or without aminoglycosides (RR 0.31, 95% 0.07 to 1.50), and also when vancomycin dosing was guided by serum levels (RR 0.22, 95% CI 0.10 to 0.52).

AUTHORS' CONCLUSIONS

Teicoplanin and vancomycin are both effective in treating those with proven or suspected infection; however the incidence of adverse effects including nephrotoxicity was lower with teicoplanin. There were no cases of AKI needing dialysis. It remains unclear whether the differential effect on kidney function should influence which antibiotic be prescribed, although it may be reasonable to consider teicoplanin for patients at higher risk for AKI needing dialysis.

The potential value of Clostridium difficile vaccine: an economic computer simulation model

Efforts are currently underway to develop a vaccine against Clostridium difficile infection (CDI). We developed two decision analytic Monte Carlo computer simulation models: (1) an Initial Prevention Model depicting the decision whether to administer C. difficile vaccine to patients at-risk for CDI and (2) a Recurrence Prevention Model depicting the decision whether to administer C. difficile vaccine to prevent CDI recurrence. Our results suggest that a C. difficile vaccine could be cost-effective over a wide range of C. difficile risk, vaccine costs, and vaccine efficacies especially, when being used post-CDI treatment to prevent recurrent disease.

European Society of Clinical Microbiology and Infectious Diseases (ESCMID): treatment guidance document for Clostridium difficile infection (CDI)

Clostridium difficile infection (CDI) is a potentially fatal illness with an increasing incidence worldwide. Despite extensive ongoing research into CDI treatment, management of CDI still poses important problems, such as a high propensity to relapse and refractoriness to treatment, especially when there is an ileus and oral drugs cannot be administered. This guideline evaluates the available literature, discusses criteria for disease severity and provides recommendations for CDI treatment, indicating level of evidence and strength of recommendation.