Best strategies in recurrent or persistent Clostridium difficile infection

"Primum, non nocere": The Epidemiology of Toxigenic Clostridioides difficile Strains in the Antibiotic Era-Insights from a Prospective Study at a Regional Infectious Diseases Hospital in Eastern Europe

Clostridioides difficile infection (CDI), though identified nearly five decades ago, still remains a major challenge, being associated with significant mortality rates. The strains classified as hypervirulent, notably 027/NAP1/BI, have garnered substantial attention from researchers and clinicians due to their direct correlation with the severity of the disease. Our study aims to elucidate the significance of toxigenic Clostridioides difficile (CD) strains in the clinical and therapeutic aspects of managing patients diagnosed with CDI. We conducted a single-center prospective study, including patients with CDI from north-eastern Romania. We subsequently conducted molecular biology testing to ascertain the prevalence of the presumptive 027/NAP1/BI strain within aforementioned geographic region. The patients were systematically compared and assessed both clinically and biologically, employing standardized and comparative methodologies. The study enrolled fifty patients with CDI admitted between January 2020 and June 2020. Among the investigated patients, 43 (86%) exhibited infection with toxigenic CD strains positive for toxin B genes (tcdB), binary toxin genes (cdtA and cdtB), and deletion 117 in regulatory genes (tcdC), while the remaining 7 (14%) tested negative for binary toxin genes (cdtA and cdtB) and deletion 117 in tcdC. The presence of the presumptive 027/NAP1/BI strains was linked to a higher recurrence rate (35.56%, p = 0.025), cardiovascular comorbidities (65.1% vs. 14.2%, p = 0.016), and vancomycin treatment (55.8% vs. 14.3%, p = 0.049). The findings of our investigation revealed an elevated incidence of colitis attributed to presumptive 027/NAP1/BI. Despite the prevalence of the presumptive 027 strain and its associated heightened inflammation among the patients studied, no significant differences were observed regarding the clinical course or mortality outcomes.

Clostridium difficile septic arthritis and periprosthetic joint infection in a patient with acute lymphoblastic leukaemia, T-/B-lymphocytopenia and hypogammaglobulinemia - a case report and review of the literature

To the best of our knowledge, we report the first Clostridium difficile infection in a native hip joint with subsequent prosthetic joint infection in a patient at a state of hypogammaglobulinemia. The infection developed following chemotherapy for B-cell precursor acute lymphoblastic leukaemia (BCP-ALL). After chemotherapy, hip arthroplasty was performed for destructive septic arthritis. However, infection in the hip persisted with several failing revisions for more than 3 years, until ultimately hypogammaglobulinemia and T-/B-lymphocytopenia were diagnosed, and supplementation with i.v. immunoglobulins was able to achieve infection control.

Characterization of the impact of rpoB mutations on the in vitro and in vivo competitive fitness of Clostridium difficile and susceptibility to fidaxomicin

Objectives

To establish the role of specific, non-synonymous SNPs in the RNA polymerase β subunit (rpoB) gene in reducing the susceptibility of Clostridium difficile to fidaxomicin and to explore the potential in vivo significance of rpoB mutant strains.

Methods

Allelic exchange was used to introduce three different SNPs into the rpoB gene of an erythromycin-resistant derivative (CRG20291) of C. difficile R20291. The genome sequences of the created mutants were determined and each mutant analysed with respect to growth and sporulation rates, toxin A/B production and cytotoxicity against Vero cells, and in competition assays. Their comparative virulence and colonization ability was also assessed in a hamster infection model.

Results

The MIC of fidaxomicin displayed by three mutants CRG20291-TA, CRG20291-TG and CRG20291-GT was substantially increased (>32, 8 and 2 mg/L, respectively) relative to that of the parent strain (0.25 mg/L). Genome sequencing established that the intended mutagenic substitutions in rpoB were the only changes present. Relative to CRG20291, all mutants had attenuated growth, were outcompeted by the parental strain, had lower sporulation and toxin A/B production capacities, and displayed diminished cytotoxicity. In a hamster model, virulence of all three mutants was significantly reduced compared with the progenitor strain, whereas the degree of caecum colonization was unaltered.

Conclusions

Our study demonstrates that particular SNPs in rpoB lead to reduced fidaxomicin susceptibility. These mutations were associated with a fitness cost in vitro and reduced virulence in vivo.

Cost-Effectiveness of Fecal Microbiota Transplantation in the Treatment of Recurrent Clostridium Difficile Infection: A Literature Review

Clostridium difficile (C. difficile) is a common cause of antibiotic-­associated diarrhea (AAD), being responsible for 15­-25% of all AAD cases. The purpose of this literature review is to determine the cost-effectiveness of fecal microbiota transplantation (FMT) and how it compares in this regard to the standard treatments of choice for recurrent C. difficile infection (CDI). The review of the literature along with the evaluation of three comparative cost effective analyses yielded findings consistent with the view that FMT is the most cost-effective option in treating recurrent CDI. There are some (but considerably less) data indicating that FMT may be a cost effective strategy in treating initial CDI, as well. The superior cost-effectiveness of FMT as compared to the preferred standards of treatment for recurrent CDI suggest FMT use should become more integrated in routine clinical practice. Increased utilization of FMTs would allow for better control of this increasingly problematic disease as well as lower costs associated with its management.

Safety, Tolerability, Systemic Exposure, and Metabolism of CRS3123, a Methionyl-tRNA Synthetase Inhibitor Developed for Treatment of Clostridium difficile, in a Phase 1 Study

Clostridium difficile causes antibiotic-associated diarrhea and is a major public health concern. Current therapies disrupt the protective intestinal flora, do not reliably prevent recurrent infections, and will be decreasingly effective should less susceptible strains emerge. CRS3123 is an oral agent that inhibits bacterial methionyl-tRNA synthetase and has potent activity against C. difficile and aerobic Gram-positive bacteria but little activity against Gram-negative bacteria, including anaerobes. This first-in-human, double-blind, placebo-controlled, dose escalation study evaluated the safety and systemic exposure of CRS3123 after a single oral dose in healthy adults. Five cohorts of eight subjects each received CRS3123 or placebo in a 3:1 ratio. Doses for the respective active arms were 100 mg, 200 mg, 400 mg, 800 mg, and 1,200 mg. Blood and urine were collected for pharmacokinetic analysis. CRS3123 concentrations were measured with validated LC-MS/MS techniques. There were no serious adverse events or immediate allergic reactions during administration of CRS3123. In the CRS3123-treated groups, the most frequent adverse events were decreased hemoglobin, headache, and abnormal urine analysis; all adverse events in the active-treatment groups were mild to moderate, and their frequency did not increase with dose. Although CRS3123 systemic exposure increased at higher doses, the increase was less than dose proportional. The absorbed drug was glucuronidated at reactive amino groups on the molecule, which precluded accurate pharmacokinetic analysis of the parent drug. Overall, CRS3123 was well tolerated over this wide range of doses. This safety profile supports further investigation of CRS3123 as a treatment for C. difficile infections. (This study has been registered at ClinicalTrials.gov under identifier NCT01551004.).

First recurrence of Clostridium difficile infection: clinical relevance, risk factors, and prognosis

Therapy for recurrent Clostridium difficile-associated diarrhea (CDAD) is challenging. We evaluated the frequency, associated risk factors, and prognosis of first CDAD recurrences. Prospective cohort study of all consecutive cases of primary CDAD diagnosed in a university hospital from January 2006 to June 2013. Recurrent infection was defined as reappearance of symptoms within 8 weeks of the primary diagnosis, provided that CDAD symptoms had previously resolved and a new toxin test was positive. Predictors of a first episode of recurrent CDAD were determined by logistic regression analysis. In total, 502 patients (51.6 % men) with a mean age of 62.3 years (SD 18.5) had CDAD; 379 (76 %) were cured, 61 (12 %) had a first recurrence, 52 (10 %) died within 30 days of the CDAD diagnosis, nine (2 %) required colectomy, and one was lost to follow-up. Among the 61 patients with a first recurrence, 36 (59.3 %) were cured, 15 (23.7 %) had a second recurrence, nine (15.3 %) died, and one (1.7 %) required colectomy. On multivariate analysis, age older than 65 years (OR 2.04; 95 % CI, 1.14-3.68; P < 0.02) and enteral nutrition (OR, 3.62; 95%CI, 1.66-7.87; P < 0.01) were predictors of a first recurrence. A risk score was developed for first CDAD recurrence using the predictive factors and selected biological variables. In our CDAD cohort, 12 % of patients had a first recurrence of this disease, in which the prognosis was less favorable than that of the primary episode, as it heralded a higher risk of additional recurrences. Patient age and enteral nutrition were predictors of a first recurrence.

A Review of Management of Clostridium difficile Infection: Primary and Recurrence

Clostridium difficile infection (CDI) is a potentially fatal illness, especially in the elderly and hospitalized individuals. The recurrence and rates of CDI are increasing. In addition, some cases of CDI are refractory to the currently available antibiotics. The search for improved modalities for the management of primary and recurrent CDI is underway. This review discusses the current antibiotics, fecal microbiota transplantation (FMT) and other options such as immunotherapy and administration of non-toxigenic Clostridium difficile (CD) for the management of both primary and recurrent CDI.

Clostridium difficile infection: update on diagnosis, epidemiology, and treatment strategies

BACKGROUND

Clostridium difficile infection (CDI) has increased in incidence and severity over the past quarter century, and is now considered a major cause of healthcare-associated infections.

METHODS

Review of the pertinent English-language medical literature.

RESULTS

There has been a substantial change in the management of CDI. The emergence of the NAP1/BI/O27 strain in the early to mid-2000s has been associated with more severe forms of CDI. The pathophysiology, epidemiology, clinical manifestations and diagnosis, as well as new strategies for medical and surgical management are discussed in this review.

CONCLUSIONS

Clostridium difficile infection can range from benign diarrhea to severe disease associated with substantial morbidity and mortality. Treatment modalities vary based on disease severity and timing of onset. The mainstay of medical treatment remains metronidazole and oral/rectal vancomycin. New management strategies are evolving, including adjunctive treatments such as monoclonal antibodies, vaccination, and fecal transplant. In patients with severe disease or clinical deterioration, early surgical consultation for total colectomy or loop ileostomy may be life-saving. Infection control measures are vital to mitigating the spread of CDI.

Persistent and Recurrent Clostridium difficile Colitis

Clostridium difficile infection (CDI) is the most frequent cause of nosocomial diarrhea. It has become a significant dilemma in the treatment of patients, and causes increasing morbidity that, in extreme cases, may result in death. Persistent and recurrent disease hamper attempts at eradication of this infection. Escalating levels of treatment and novel therapeutics are being utilized and developed to treat CDI. Further trials are warranted to definitively determine what protocols can be used to treat persistent and recurrent disease.

Selection of nanobodies that block the enzymatic and cytotoxic activities of the binary Clostridium difficile toxin CDT

The spore-forming gut bacterium Clostridium difficile is the leading cause of antibiotic-associated diarrhea in hospitalized patients. The major virulence factors are two large glucosylating cytotoxins. Hypervirulent strains (e.g. ribotype 027) with higher morbidity and mortality additionally produce the binary CDT toxin (Clostridium difficile transferase) that ADP-ribosylates actin and induces microtubule-based cell protrusions. Nanobodies are robust single domain antibodies derived from camelid heavy chain antibodies. Here we report the generation of functional nanobodies against the enzymatic CDTa and the heptameric receptor binding subunit CDTb. The nanobodies were obtained from a variable-domain repertoire library isolated from llamas immunized with recombinant CDTa or CDTb. Five CDTa-specific nanobodies blocked CDTa-mediated ADP-ribosylation of actin. Three CDTa-specific and two CDTb-specific nanobodies neutralized the cytotoxicity of CDTa+b. These nanobodies hold promise as new tools for research, diagnosis and therapy of C. difficile associated disease.

Vaccines against Clostridium difficile

Clostridium difficile infection (CDI) is recognized as a major cause of nosocomial diseases ranging from antibiotic related diarrhea to fulminant colitis. Emergence during the last 2 decades of C. difficile strains associated with high incidence, severity and lethal outcomes has increased the challenges for CDI treatment. A limited number of drugs have proven to be effective against CDI and concerns about antibiotic resistance as well as recurring disease solicited the search for novel therapeutic strategies. Active vaccination provides the attractive opportunity to prevent CDI, and intense research in recent years led to development of experimental vaccines, 3 of which are currently under clinical evaluation. This review summarizes recent achievements and remaining challenges in the field of C. difficile vaccines, and discusses future perspectives in view of newly-identified candidate antigens.

A rare case intractable diarrhea secondary to Clostridium difficile and cytomegalovirus coinfection

PATIENT

Male, 63 FINAL DIAGNOSIS: Cytomegalo virus (CMV) infection Symptoms: Diarrhea Medication:- Clinical Procedure:- Specialty: Infectious Diseases.

OBJECTIVE

Unusual clinical course.

BACKGROUND

Coinfection with cytomegalovirus in a patient with Clostridium difficile persistent diarrhea and colitis can lead to a delay in diagnosis and treatment.

CASE REPORT

A 63-year-old man with squamous cell carcinoma of the lower lip, status post surgical resection and currently on chemoradiation presented with intractable diarrhea and abdominal pain. Initial workup showed Clostridium difficile diarrhea with pancolitis. Diarrhea persisted despite being on antibiotics and bacteriological cure for C. difficile. Further noninvasive work up revealed associated cytomegalovirus infection, and patient had a dramatic response to ganciclovir without any relapse.

CONCLUSIONS

Physicians should be cognizant about other causes of diarrhea and colitis in immunocompromised patient when treatment for primary diagnosis fails to resolve their symptoms.

Treatment approaches including fecal microbiota transplantation for recurrent Clostridium difficile infection (RCDI) among infectious disease physicians

BACKGROUND

Clostridium difficile infection (CDI) was the most common nosocomial infection in the U.S. in 2010. Most cases of CDI respond to a standard course of antibiotics, but recurrent C. difficile infections (RCDI) are increasingly common. Given the lack of randomized clinical trials, it is important to understand how infectious disease physicians are managing RCDI to inform future clinical research.

METHODS

An electronic survey was conducted among members of the Emerging Infections Network (EIN) in October 2012. Respondents were asked to answer specific questions about their treatment approaches toward patients with CDI, including fecal microbiota transplantation (FMT).

RESULTS

The overall response rate was 621/1212 (51%). The vast majority of respondents had cared for small to moderate numbers of patients with CDI over the prior 6 months, and reported recurrence rates were consistent with published data. Preferred treatment regimens for RCDI showed significant variance from recommendations published in national guidelines. Eighty percent (424/527) of the respondents would consider FMT for patients with RCDI, and of 149 who had FMT available at their institution, 107 (72%) had actually treated >1 patient with FMT in the preceding year. However, significant barriers to institutional adoption of FMT remain for many respondents, despite very good success rates with its use.

CONCLUSIONS

Physicians who regularly care for patients with CDI use a variety of treatment approaches for treating severe or recurrent CDI cases. The results of our survey demonstrate that FMT is used by a growing number of infectious disease providers as an effective and safe treatment alternative for patients with multiple recurrences of C. difficile infection.

Antimicrobial susceptibility of clostridium difficile clinical isolates in iran

Background

Clostridium difficile infection (CDI) is major growing problem in hospitals and its high incidence has been reported in recent years.

Objectives

The aim of this study was to investigate the antimicrobial susceptibility patterns of C. difficile clinical isolates against antibiotics commonly used for treatment CDI in hospitalized patients.

Material and Methods

During a 12 month study, 75 C. difficile isolates were collected from 390 patients with CDI. All samples were treated with alcohol and yeast extract broth. The treated suspensions were cultured on a selective cycloserine cefoxitin fructose agar (CCFA) supplemented with 5% sheep blood and incubated in anaerobic conditions, at 37 °C for 5 days. Cdd-3, tcdA and tcdB genes were identified using PCR assay.

Results

The prevalence of A⁺B⁺ , A⁺ B^- and A^- B⁺ strains were 64(85.3%), 5(6.7%) and 6(8%) respectively. In vitro susceptibility of 75 clinical isolates of C. difficile to 5 antimicrobial agents, including metronidazole, vancomycin, clindamycin, erythromycin and cefotaxime were investigated by Clinical and Laboratory Standards Institute (CLSI) agar dilution method. Metronidazole and vancomycin had good activity against C. difficile isolates with MIC90s of 2 and 1 µg/ml, respectively. Seventy one (94.6%) of strains was inhibited by concentrations that did not exceed 2µg/ml for metronidazole. Resistant to metronidazole observed in 5.3% of isolates. Forty three (57.3%) of the isolates were resistant to erythromycin. Of 43 resistant strains to erythromycin, 9 (12%) isolates had high-level MIC of more than 64 µg/ml. All strains were resistant to cefotaxime. Sixty seven (89.3%) isolates were resistant to clindamycin (MIC90s > 256 µg/ml) and only 6.7% were sensitive to clindamycin. Multidrug-resistant (three or more antibiotics) was seen in 36(48%) isolates.

Conclusions

Metronidazole and vancomycin still seem to be most effective drugs for treatment CDI.

Clostridium difficile infection in children: a comprehensive review

OBJECTIVE

To provide a comprehensive review of the literature relating to Clostridium difficile (C. difficile) infection (CDI) in the pediatric population.

METHODS

Two investigators conducted independent searches of PubMed, Web of Science, and Scopus until March 31st, 2013. All databases were searched using the terms 'Clostridium difficile infection', 'Clostridium difficile associated diarrhea' 'antibiotic associated diarrhea', 'C. difficile', in combination with 'pediatric' and 'paediatric'. Articles which discussed pediatric CDI were reviewed and relevant cross references also read and evaluated for inclusion. Selection bias could be a possible limitation of this approach.

FINDINGS

There is strong evidence for an increased incidence of pediatric CDI. Increasingly, the infection is being acquired from the community, often without a preceding history of antibiotic use. The severity of the disease has remained unchanged. Several medical conditions may be associated with the development of pediatric CDI. Infection prevention and control with antimicrobial stewardship are of paramount importance. It is important to consider the age of the child while testing for CDI. Traditional therapy with metronidazole or vancomycin remains the mainstay of treatment. Newer antibiotics such as fidaxomicin appear promising especially for the treatment of recurrent infection. Conservative surgical options may be a life-saving measure in severe or fulminant cases.

CONCLUSIONS

Pediatric providers should be cognizant of the increased incidence of CDI in children. Early and judicious testing coupled with the timely institution of therapy will help to secure better outcomes for this disease.

[Clostridium difficile infection: epidemiology, disease burden and therapy]

INTRODUCTION

C. difficile causes 25 percent of the antibiotic associated infectious nosocomial diarrhoeas. C. difficile infection is a high-priority problem of public health in each country. The available literature of C. difficile infection's epidemiology and disease burden is limited.

AIM

Review of the epidemiology, including seasonality and the risk of recurrences, of the disease burden and of the therapy of C. difficile infection.

METHOD

Review of the international and Hungarian literature in MEDLINE database using PubMed up to and including 20th of March, 2012.

RESULTS

The incidence of nosocomial C. difficile associated diarrhoea is 4.1/10 000 patient day. The seasonality of C. difficile infection is unproved. 20 percent of the patients have recurrence after metronidazole or vancomycin treatment, and each recurrence increases the chance of a further one. The cost of C. difficile infection is between 130 and 500 thousand HUF (430 € and 1665 €) in Hungary.

CONCLUSIONS

The importance of C. difficile infection in public health and the associated disease burden are significant. The available data in Hungary are limited, further studies in epidemiology and health economics are required.

[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.

Clostridium difficile enteritis: A report of two cases and systematic literature review

Clostridium difficile (C. difficile) is the most common cause of healthcare associated infectious diarrhea. In the last decade, the incidence of C. difficile infection has increased dramatically. The virulence of C. difficile has also increased recently with toxigenic strains developing. C. difficile is generally a disease of the colon and presents with abdominal pain and diarrhea due to colitis. However, C. difficile enteritis has been reported rarely. The initial reports suggested mortality rates as high as 66%. The incidence of C. difficile enteritis appears to be increasing in parallel to the increase in colonic infections. We present two cases of patients who had otherwise uneventful abdominal surgery but subsequently developed C. difficile enteritis. Our literature review demonstrates 81 prior cases of C. difficile enteritis described in case reports. The mortality of the disease remains high at approximately 25%. Early recognition and intervention may reduce the high mortality associated with this disease process.

In vitro activity of cadazolid against Clostridium difficile strains isolated from primary and recurrent infections in Stockholm, Sweden

One hundred thirty-three Clostridium difficile strains were collected from 71 patients and analyzed for the presence of C. difficile toxin B by the cell cytotoxicity neutralization assay, genes for toxin A, toxin B, binary toxin and TcdC deletion by PCR. All strains were also PCR-ribotyped and analyzed for sporulation frequency. The MICs of the isolates were determined against cadazolid and seven other antimicrobial agents by the agar dilution method. All isolates were positive for toxin B by the cell cytotoxicity neutralization assay. One hundred fourteen isolates were positive for toxin A and B and 16 isolates were positive for toxin A, toxin B and binary toxin by PCR. Three isolates were negative for toxin A but positive for toxin B. Thirty-three different ribotypes were identified. No strain of ribotype 027 was found. No differences in sporulation were noticed between the primary and recurrent isolates. All 133 isolates were sensitive to cadazolid (0.064-0.5 mg/l), fidaxomicin (0.008-0.125 mg/l), metronidazole (0.125-2 mg/l), vancomycin (0.125-1 mg/l) and tigecycline (0.032-0.25 mg/l). Three isolates were resistant to linezolid (8 mg/l), 15 isolates were resistant to moxifloxacin (8-32 mg/l) and 103 isolates were resistant to clindamycin (8-256 mg/l). No association between toxins A, B and binary toxin, ribotypes or the sporulation and the sensitivity to cadazolid could be found. Cadazolid has a potent in vitro activity against C. difficile.

Pseudomembranous colitis due to Clostridium difficile as a cause of perineal necrotising fasciitis

Although rare, pseudomembranous colitis may be a cause of perineal necrotising fasciitis in a context of immunosuppression, as in the case we report. This origin must be quickly identified because the therapeutic management, especially surgery, is unlikely to be the same as usual. Similarly, antibiotic treatment is also a matter of discussion due to the potential deleterious role of antibiotics in pseudomembranous colitis.

Rifaximin in the treatment of recurrent Clostridium difficile infection

BACKGROUND

Clostridium difficile can cause severe antibiotic-associated colitis. Conventional treatments with metronidazole and vancomycin improve symptoms, but after discontinuation of treatment, C. difficile infection (CDI) recurs in a number of patients. Rifaximin is a rifamycin-based non-systemic antibiotic that has effect against C. difficile.

AIM

To assess the effectiveness of rifaximin in recurrent C. difficile infection.

METHODS

We retrospectively evaluated the records of 32 patients who were treated with rifaximin for recurrent C. difficile infection. The symptoms were evaluated 12 weeks after the start of treatment and patient records were followed up until 1 year after treatment.

RESULTS

The mean age of the patients was 55 years (median 64, range: 19-84 years). Before the initiation of rifaximin therapy, the patients had undergone, on the average, 4.4 (range: 2-12) antimicrobial courses for C. difficile infection. C. difficile strain typing was performed in 27 patients. Eight (30%) patients had a strain with a DNA profile compatible with the BI/NAP1/027 ribotype. Antibiotic susceptibilities were determined of isolates from 22 patients. Most isolates (68%) had very low MIC-values for rifampin (<0.002 μg/mL) and the highest MIC value was 3.0 μg/mL. Isolates with a DNA profile compatible with the BI/NAP1/027 ribotype had, on the average, higher MICs of rifampin. After 12 weeks 17 (53%) patients had no relapse. The MIC value of rifampin seemed to predict the response to rifaximin treatment.

CONCLUSIONS

Rifaximin is a safe treatment for C. difficile infection. It has a reasonable effect in C. difficile infection and it can be considered as an optional treatment for recurrent C. difficile infection.

Consequences of Clostridium difficile infection: understanding the healthcare burden

Clostridium difficile is the leading cause of infectious nosocomial diarrhoea in developed countries, with a measured incidence of approximately five episodes per 10,000 days of hospital stay in Europe. Accurate diagnosis of C. difficile infection (CDI) is a prerequisite for obtaining reliable epidemiological data, but in many European countries diagnosis is probably suboptimal. A significant percentage of CDI cases are missed because clinicians often fail to request tests for C. difficile toxins in cases of unexplained diarrhoea. In addition, some laboratories continue to use tests of low sensitivity or apply them inappropriately. In one study in Spain, failure to request CDI testing in more than two-thirds of patients with unexplained diarrhoea led to significant underdiagnosis of cases. A recent pan-European survey revealed huge discrepancies in the rate of CDI testing across Europe, which suggests that epidemiological reports underestimate the true incidence of CDI in many parts of Europe. This is important because, as this review of the clinical and economic burden of CDI illustrates, infection with C. difficile imposes a significant burden not only on patients, owing to increased morbidity and mortality, but also on healthcare systems and society in general. On the basis of current incidence rates, annual costs for management of CDI amount to approximately $800 million in the USA and €3000 million in Europe. Moreover, estimates suggest that costs associated with recurrent CDI can exceed those of primary CDI. Measures to more effectively prevent CDI and reduce CDI recurrence rates may help to reduce this burden.

Antibiotic heterogeneity optimizes antimicrobial prescription and enables resistant pathogen control in the intensive care unit

BACKGROUND

Multi-drug-resistant organisms (MDRO) complicate care increasingly on the general ward and in the emergency department, operating room, and intensive care unit (ICU). Whereas barrier precautions are important in limiting transmission of MDRO between patients, few tactics have been defined that reduce the genesis of MDRO.

METHOD

Review of pertinent English-language literature.

RESULTS

Antibiotic heterogeneity practices, as part of an overall antimicrobial drug stewardship program, offer one readily deployable means to reduce selection pressure for MDRO development in the ICU. The data underpinning this approach and data derived from its use indicate that, especially in surgical ICUs, heterogeneity of antibiotic prescribing can preserve or restore microbial ecology, reduce the prevalence of MDRO and the incidence of infections caused thereby, and facilitate the implementation and effectiveness of other antibiotic-sparing tactics, such as de-escalation.

CONCLUSION

Heterogeneity of antibiotic prescribing is effective in preventing the dissemination of MDRO pathogens.

Ribotyping of Clostridium difficile strains associated with nosocomial transmission and relapses in a Swedish County

Clostridium difficile is an emerging threat in hospital environments. To analyse possible transmission and to distinguish between relapse and reinfection a collection of C. difficile isolates, sampled from 162 consecutive episodes of C. difficile infection, were PCR ribotyped. Two ribotypes (001 and 012) were prone to cause nosocomial acquisition. Moreover, ribotype 001 had a tendency to cause relapses as almost one in two patients with this ribotype had one or more relapses. By using PCR ribotyping strains inclined to cause relapses and strains associated with hospital transmission might be detected. This enables optimized hygiene measures and may improve the choice of treatment regimen.

Amixicile, a novel inhibitor of pyruvate: ferredoxin oxidoreductase, shows efficacy against Clostridium difficile in a mouse infection model

Clostridium difficile infection (CDI) is a serious diarrheal disease that often develops following prior antibiotic usage. One of the major problems with current therapies (oral vancomycin and metronidazole) is the high rate of recurrence. Nitazoxanide (NTZ), an inhibitor of pyruvate:ferredoxin oxidoreductase (PFOR) in anaerobic bacteria, parasites, Helicobacter pylori, and Campylobacter jejuni, also shows clinical efficacy against CDI. From a library of ∼250 analogues of NTZ, we identified leads with increased potency for PFOR. MIC screens indicated in vitro activity in the 0.05- to 2-μg/ml range against C. difficile. To improve solubility, we replaced the 2-acetoxy group with propylamine, producing amixicile, a soluble (10 mg/ml), nontoxic (cell-based assay) lead that produced no adverse effects in mice by oral or intraperitoneal (i.p.) routes at 200 mg/kg of body weight/day. In initial efficacy testing in mice treated (20 mg/kg/day, 5 days each) 1 day after receiving a lethal inoculum of C. difficile, amixicile showed slightly less protection than did vancomycin by day 5. However, in an optimized CDI model, amixicile showed equivalence to vancomycin and fidaxomicin at day 5 and there was significantly greater survival produced by amixicile than by the other drugs on day 12. All three drugs were comparable by measures of weight loss/gain and severity of disease. Recurrence of CDI was common for mice treated with vancomycin or fidaxomicin but not for mice receiving amixicile or NTZ. These results suggest that gut repopulation with beneficial (non-PFOR) bacteria, considered essential for protection against CDI, rebounds much sooner with amixicile therapy than with vancomycin or fidaxomicin. If the mouse model is indeed predictive of human CDI disease, then amixicile, a novel PFOR inhibitor, appears to be a very promising new candidate for treatment of CDI.

Systematic review: faecal transplantation for the treatment of Clostridium difficile-associated disease

BACKGROUND

Management of recurrent Clostridium difficile-associated disease (CDAD), particularly in elderly patients, remains clinically challenging. Faecal transplantation (FT) may restore normal microbiota and break the cycle of recurrent CDAD.

AIM

To critically appraise the clinical research evidence on the safety and effectiveness of FT compared with standard care in the treatment of patients with CDAD.

METHODS

A comprehensive literature search was conducted by a research librarian to identify relevant studies published between 2000 and 2011. The Cochrane Library, PubMed, EMBASE, CINAHL, Biological Abstracts, BIOSIS Previews and Web of Science were searched using the following Medical Subject Headings (MeSH) terms and keywords, alone or in combination: Clostridium infections/Clostridium difficile/pseudomembranous/colitis/faeces/rectal/colon flora/gastrointestinal/nasogastric tube/enema/donor/transplant/infusion/bacteriotherapy/human probiotic infusion. Methodological quality of the included case series studies was assessed in terms of patient selection criteria, consecutive recruitment, prospective data collection, reporting of lost to follow-up, and follow-up rates.

RESULTS

No controlled studies were found. Based on the weak evidence from seven full-text case series studies of 124 patients with recurrent/refractory CDAD, FT appears to be a safe and effective procedure. In most cases (83%) symptoms improved immediately after the first FT procedure, and some patients stayed diarrhoea free for several months or years.

CONCLUSIONS

Although these results appear to be promising, the treatment effects of faecal transplantation cannot be determined definitively in the absence of a control group. Results from randomised controlled trials that compare faecal transplantation to oral vancomycin without or with a taper regimen will help to better define the role of faecal transplantation in the management of recurrent CDAD.

Rifaximin in Combination with Metronidazole and Oral Vancomycin for the Treatment of an Initial Episode of Clostridium difficile–Associated Diarrhea: Case Report and Literature Review

Purpose

Example of successful use of rifaximin in the treatment of an apparent Clostridium difficile infection refractory to vancomycin and metronidazole with literature review.

Case Summary

A 69-year-old Caucasian female developed C. difficile infectious diarrhea, confirmed by enzyme immunoassay (EIA) test. Following diagnosis, the patient was initiated on a treatment regimen of intravenous (IV) metronidazole and oral vancomycin. The patient sought additional medical treatment 3 days after initiating this treatment regimen. She presented with continued symptoms of diarrhea, bloating, anorexia, weakness, and leukocytosis nonresponsive to metronidazole and vancomycin. After a total of 7 days of treatment with metronidazole and vancomycin, the patient remained symptomatic with loose stools occurring approximately every 2 hours. Oral rifaximin 400 mg 3 times a day was added to the regimen, after which the patient's symptoms improved rapidly.

Conclusion

A patient with presumed C. difficile–associated diarrhea refractory to metronidazole and vancomycin was successfully treated after the addition of oral rifaximin 400 mg 3 times a day. Based on current literature and this case, rifaximin should not replace metronidazole or vancomycin as primary therapy for presumed or diagnosed C. difficile but should be retained as a useful alternative, especially in light of limited alternatives.

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.

Clostridium difficile infection: an update on epidemiology, risk factors, and therapeutic options

PURPOSE OF REVIEW

The incidence and severity of Clostridium difficile infection (CDI) around the world has increased over the past 20 years due to the emergence of hypervirulent strains, increased use and misuse of antibiotics, and the increase of susceptible at-risk populations. Treatments currently available for CDI are inadequate to impede the increasing spread and virulence of the infection, avoid recurrence in chronic patients or prevent infection in at-risk populations.

RECENT FINDINGS

New and promising evidence has been presented during the past year, focusing on two major points: preservation of gut microflora and optimization of immune response to CDI and toxins.

SUMMARY

The review aims to summarize the most recent evidence available on the epidemiology, risk factors and treatment of CDI. New antibiotics with selected action on C. difficile and limited effect on microflora (fidaxomicin) and donor fecal transplantation seem to have a relevant efficacy in treating CDI and reducing its recurrence. The use of selected monoclonal antibodies directed against C. difficile toxins in addition to standard therapy is a new, promising approach for the treatment of recurrent cases. Vaccination could be an additional weapon against CDI. New robust data are needed before recommendations can be made to abandon current treatment based on vancomycin and metronidazole and move toward new frontiers.