Clostridium difficile infections: emerging epidemiology and new treatments

Vancomycin Use in Children and Neonates across Three Decades: A Bibliometric Analysis of the Top-Cited Articles

Vancomycin is frequently prescribed in pediatrics, especially in intensive care unit settings, to treat Gram-positive bacterial infections. This work aims to collect the top-cited articles of pediatric and infectious diseases areas to gather the current evidence and gaps of knowledge on the use of vancomycin in these populations. The most relevant journals reported in the "pediatrics" and "infectious diseases" categories of the 2019 edition of Journal Citation Reports were browsed. Articles with more than 30 citations and published over the last three decades were collected. A bibliometric analysis was performed and 115 articles were retrieved. They were published in 21 journals, with a median impact factor of 4.6 (IQR 2.9-5.4). Sixty-eight of them (59.1%) belonged to "infectious diseases" journals. The most relevant topic was "bloodstream/complicated/invasive infections", followed by "antibiotic resistance/MRSA treatment". As for population distribution, 27 articles were on children only and 27 on neonates, most of which were from intensive care unit (ICU) settings. The current literature mainly deals with vancomycin as a treatment for severe infections and antibiotic resistance, especially in neonatal ICU settings. Lately, attention to new dosing strategies in the neonatal and pediatric population has become a sensible topic.

Fructooligosaccharides and mannose affect Clostridium difficile adhesion and biofilm formation in a concentration-dependent manner

The aim of this study was to investigate the effects that prebiotic and candidates for prebiotics on Clostridium difficile strains to adhere to various human epithelial cell lines and to compare the adhesive properties of specific C. difficile strains. We also sought to examine the effect of different concentrations of fructooligosaccharides and mannose on the formation of biofilms by C. difficile strains. The influence of cellobiose, fructooligosaccharides, inulin, mannose, and raffinose on the adherence properties of various C. difficile strains, including motile 630, non-motile M120, and 10 clinical motile ribotype 027 strains, to non-mucous secreting HT-29, mucous secreting HT-29 MXT, and CCD 841 CoN cells lines. The most effective prebiotics were used in biofilm formation assays. We demonstrated that all C. difficile strains adhered to all cell lines. However, the C. difficile M120 non-motile strain was statistically more likely to adhere to all three cell lines (CFU median, 40) compared to the motile strains (CFU median, 3; p < 0.001). Furthermore, among the carbohydrates examined, only fructooligosaccharides and mannose were found to significantly decrease adhesion (p < 0.001) of C. difficile strains. Alternatively, using a biofilm assay, we observed, via confocal laser scanning microscopy, that sub-inhibitory concentrations (1%) of fructooligosaccharides and mannose functioned to increase biofilm formation by C. difficile. We demonstrated that specific prebiotics and candidate prebiotics exhibit varying anti-adhesive properties towards C. difficile in vitro and that treatment with sub-inhibitory concentrations of prebiotics can cause an increase in biofilm formation by C. difficile.

Nagging Presence of Clostridium difficile Associated Diarrhoea in North India

Introduction

Clostridium Difficile Associated Diarrhoea (CDAD) is a significant cause of morbidity in hospitalised patients worldwide. The data on clinical epidemiology of this disease in Indian subcontinent is scarce.

Aim

To evaluate the risk factors and clinical course of patients with CDAD.

Materials and Methods

A cross-sectional study was planned at our tertiary care centre, All India Institute of Medical Sciences, whereby, all patients who had nosocomial diarrhea between 2010 and 2014 were included in the study. Their clinical and laboratory profile were recorded using structured questionnaire and their stool samples were subjected to ELISA for detection of toxins A and B (Premier toxins A and B). Those patients who had toxins A and B in their stool samples were diagnosed as CDAD. The clinical and laboratory profile of CDAD patients were further analysed.

Results

A total of 791 patients with nosocomial diarrhea were included in this study. CDAD was diagnosed in a total of 48(6%) patients. The year wise breakdown of the positive patients is as follows: 7/135 (5.2%), 4/156 (2.6%), 5/141 (3.5%), 9/193 (4.7%) and 23/166 (13.8%), respectively. A total of 16/48 (33.3%) of CDAD cases belonged to the age group of 51-60 years. Malignancy (n=15, 31.25%) was the most common underlying pathological condition. All the patients had a history of antibiotic intake. Most common antibiotic used in the patients of CDAD was third generation cephalosporins (n=27, 56.25%). The use of clindamycin, carbapenems and colistin increased in the year 2014. Mean duration of hospital stay was 9.8 days. Diarrhoea was associated with fever in 50% of the patients while abdominal pain was seen in 39.6% of the patients.

Conclusion

The control of Clostridium difficile infection suffers from the rampant use of higher antibiotics. There is a need for proper implementation of antimicrobial stewardship programmes and better hospital infection control to stop the transmission of this nagging bug.

Effect of Metronidazole in Infants with Bowel Habit Change: Irrelative to the Clostridium difficile Colonization

PURPOSE

Clinical symptoms associated with Clostridium difficile infection (CDI) can vary widely. Carrier state without apparent symptoms is relatively common during infancy. The objective of this study was to determine the association of C. difficile colonization with bowel habit change and the effect of C. difficile colonization treatment on restoration of normal bowel habit.

METHODS

Between 2006 and 2014, infants at 1 to 12 months of age with diarrhea for more than 2 weeks who did not improve with conservative care were recruited from Gachon University Gil Medical Center. Infants who were followed up for at least 7 days were included. The presence or absence of C. difficile colonization, effect of metronidazole, and other medical records were reviewed. To determine the association between CDI and bowel habit change, logistic regression analysis was used.

RESULTS

Of a total of 126 infants, 74 (58.7%) were male patients. Of the 126 patients, 27 (21.4%) had C. difficile colonization. Significant (p<0.05) risk factors for C. difficile colonization included artificial milk feeding (odds ratio [OR], 4.310; 95% confidence interval [CI], 1.564-11.878), prior rotavirus vaccination (OR, 4.322; 95% CI, 1.018-18.349), and antibiotic use (OR, 4.798; 95% CI, 1.430-16.101). There was improvement in bowel habit after metronidazole therapy (OR, 0.34; 95% CI, 0.15-0.79; p<0.05), regardless of the presence or absence of C. difficile colonization.

CONCLUSION

There was no significant correlation between bowel habit change and C. difficile colonization during infancy. However, metronidazole can be used as an optional method to manage functional gastrointestinal disorders.

Recurrent Clostridium difficile infection and the microbiome

The diverse and densely populated gastrointestinal microbiota is essential for the regulation of host physiology and immune function. As our knowledge of the composition and function of the intestinal microbiota continues to expand, there is new interest in using these developments to tailor fecal microbiota transplantation (FMT) and microbial ecosystem therapeutics (MET) for a variety of diseases. The potential role of FMT and MET in the treatment of Clostridium difficile infection (CDI)-currently the leading nosocomial gastrointestinal infection-has proven highly effective for recurrent CDI, and has emerged as a paradigm shift in the treatment of this disease. The current review will serve as a summary of the key aspects of CDI, and will introduce the essential framework and challenges of FMT, as is currently practiced. MET represents the progression of conventional bacteriotherapy that fundamentally capitalizes on the restorative properties of intestinal bacterial communities and may be viewed as the culmination of a rationally designed therapeutic modality. As our understanding of the composition and function of the intestinal microbiota evolves, it will likely drive next-generation microbiota therapies for a range of medical conditions, such as inflammatory bowel disease, obesity, and metabolic syndrome.

Community-acquired Clostridium difficile infection in children: A retrospective study

BACKGROUND

Community acquired-Clostridium difficile infection (CDI) has increased also in children in the last years.

AIMS

To determine the incidence of community-acquired CDI and to understand whether Clostridium difficile could be considered a symptom-triggering pathogen in infants.

METHODS

A five-year retrospective analysis (January 2007-December 2011) of faecal specimens from 124 children hospitalized in the Niguarda Ca' Granda Hospital for prolonged or muco-haemorrhagic diarrhoea was carried out. Stool samples were evaluated for common infective causes of diarrhoea and for Clostridium difficile toxins. Patients with and without CDI were compared for clinical characteristics and known risk factors for infection.

RESULTS

Twenty-two children with CDI were identified in 5 years. An increased incidence of community-acquired CDI was observed, ranging from 0.75 per 1000 hospitalizations in 2007 to 9.8 per 1000 hospitalizations in 2011. Antimicrobial treatment was successful in all 19 children in whom it was administered; 8/22 CDI-positive children were younger than 2 years. No statistically significant differences in clinical presentation were observed between patients with and without CDI, nor in patients with and without risk factors for CDI.

CONCLUSIONS

Our study shows that Clostridium difficile infection is increasing and suggests a possible pathogenic role in the first 2 years of life.

Highlighting clinical needs in Clostridium difficile infection: the views of European healthcare professionals at the front line

BACKGROUND

Clostridium difficile infection (CDI) is the leading cause of infectious nosocomial diarrhoea in Europe. Despite increased focus, its incidence and severity are increasing in many European countries.

AIM

We developed a series of consensus statements to identify unmet clinical needs in the recognition and management of CDI.

METHODS

A consortium of European experts prepared a series of 29 statements representing their collective views on the diagnosis and management of CDI in Europe. The statements were grouped into the following six broad themes: diagnosis; definitions of severity; treatment failure, recurrence and its consequences; infection prevention and control interventions; education and antimicrobial stewardship; and National CDI clinical guidance and policy. These statements were reviewed using questionnaires by 1047 clinicians involved in managing CDI, who indicated their level of agreement with each statement.

FINDINGS

Levels of agreement exceeded the 66% threshold for consensus for 27 out of 29 statements (93.1%), indicating strong support. Variance between countries and specialties was analysed and showed strong alignment with the overall consensus scores.

CONCLUSION

Based on the consensus scores of the respondent group, recommendations are suggested for the further development of CDI services in order to reduce transmission and recurrence and to ensure that appropriate diagnosis and treatment strategies are applied across all healthcare settings.

Clinical Characteristics of Symptomatic Clostridium difficile Infection in Children: Conditions as Infection Risks and Whether Probiotics Is Effective

PURPOSE

This study investigated the clinical presentations of symptomatic Clostridium difficile infection (CDI) in children.

METHODS

We reviewed the medical records of 43 children aged <20 years who showed either positive C. difficile culture or C. difficile toxin test results between June 2010 and April 2014.

RESULTS

Of the 43 patients (mean age 6.7 years), 22 were boys. Sixteen patients (37.2%) showed both positive C. difficile culture and toxin test results. Seventeen out of 43 children (39.5%) had preexisting gastrointestinal diseases, and 26 children had other medical conditions that were risk factors for CDI. Twenty-eight children had a history of antibiotic treatment for >3 days, and the most frequently prescribed antibiotic was amoxicillin-clavulanate (35.7%). Twenty-eight patients were diagnosed with CDI despite taking probiotic supplements, most commonly Lactobacillus acidophilus (53.6%). The most common symptom was diarrhea (72.1%) at the time CDI was diagnosed. C. difficile was eradicated in 11 patients (25.6%) after treatment with oral metronidazole for 10-14 days, and in the two patients (4.6%) who required two courses of oral metronidazole. Sixteen patients (37.2%) showed clinical improvement without any treatment.

CONCLUSION

This study showed the various clinical characteristics of CDI in children and that preexisting clinical conditions favored the development of CDI. In addition, CDI was found to occur in a number of patients even after probiotic prophylaxis given in conjunction with antibiotic therapy.

Fate of Clostridium difficile during wastewater treatment and incidence in Southern Ontario watersheds

AIMS

To investigate the prevalence of Clostridium difficile encountered during sewage treatment and in water sources into which treated effluent was directly or indirectly discharged.

METHODS AND RESULTS

Samples from wastewater treatment plants (WWTPs) and rivers were collected and then enriched for Cl. difficile. Each of the isolates was subjected to toxinotyping and DNA typing using ribotyping, in addition to pulse-field gel electrophoresis. Cl. difficile was isolated from 92% (108/117) of the raw sludge and 96% (106/110) of the anaerobic digested sludge samples from two Ontario WWTPs. The pathogen was recovered from 73% (43/59) of dewatered biosolids and effluent discharge, in addition to river sediments 39% (25/64). Ribotype 078 (commonly associated with Community Acquired infections) was recovered from raw sewage (19%; 21/108), digested sludge (8%; 8/106), biosolids (35%; 15/43) and river sediments (60%; 15/25).

CONCLUSIONS

Clostridium difficile is commonly encountered in raw sewage and survives the wastewater treatment process. The pathogen can then be disseminated into the wider environment via effluent and land application of biosolids.

SIGNIFICANCE AND IMPACT OF THE STUDY

The study has illustrated the wide distribution of toxigenic Cl. difficile in WWTPs and river sediments although the clinical significance still requires to be elucidated.

Clostridium difficile as a cause of healthcare-associated diarrhoea among children in Auckland, New Zealand: clinical and molecular epidemiology

We aimed to determine the incidence of Clostridium difficile infection (CDI), the molecular epidemiology of circulating C. difficile strains and risk factors for CDI among hospitalised children in the Auckland region. A cross-sectional study was undertaken of hospitalised children <15 years of age in two hospitals investigated for healthcare-associated diarrhoea between November 2011 and June 2012. Stool specimens were analysed for the presence of C. difficile using a two-step testing algorithm including polymerase chain reaction (PCR). C. difficile was cultured and PCR ribotyping performed. Demographic data, illness characteristics and risk factors were compared between children with and without CDI. Non-duplicate stool specimens were collected from 320 children with a median age of 1.2 years (range 3 days to 15 years). Forty-six patients (14 %) tested met the definition for CDI. The overall incidence of CDI was 2.0 per 10,000 bed days. The percentage of positive tests among neonates was only 2.6 %. PCR ribotyping showed a range of strains, with ribotype 014 being the most common. Significant risk factors for CDI were treatment with proton pump inhibitors [risk ratio (RR) 1.74, 95 % confidence interval (CI) 1.09-5.59; p = 0.002], presence of underlying malignancy (RR 2.71, 95 % CI 1.65-4.62; p = 0.001), receiving chemotherapy (RR 2.70, 95 % CI 1.41-4.83; p = 0.003) and exposure to antibiotics (RR 1.17, 95 % CI 0.99-1.17; p = 0.03). C. difficile is an important cause of healthcare-associated diarrhoea in this paediatric population. The notion that neonatal populations will always have high rates of colonisation with C. difficile may not be correct. Several risk factors associated with CDI among adults were also found to be significant.

Intestinal inflammatory biomarkers and outcome in pediatric Clostridium difficile infections

OBJECTIVES

To identify specific fecal biomarkers for symptomatic Clostridium difficile infection and predictors of poor outcomes.

STUDY DESIGN

We enrolled 65 children with positive C difficile testing (cases) and 37 symptomatic controls. We also analyzed stool samples from colonized and non-colonized asymptomatic children. We performed enzyme immunoassays to determine fecal interleukin (IL)-8, lactoferrin, and phosphorylated-p38 protein concentrations, and quantitative polymerase chain reaction to determine IL-8 and chemokine ligand (CXCL)-5 RNA relative transcript abundances, and C difficile bacterial burden.

RESULTS

Of 68 asymptomatic controls, 16 were colonized with C difficile. Phosphorylated-p38 was specific for C difficile infection but lacked sensitivity. Fecal cytokines were elevated in samples from symptomatic children, whether cases or controls. In children with C difficile infection, fecal CXCL-5 and IL-8 messenger RNA abundances at diagnosis correlated with persistent diarrhea after 5 days of C difficile infection therapy and with treatment with vancomycin. When children with concomitant viral gastroenteritis were excluded, these correlations persisted. Time-to-diarrhea resolution was significantly longer in patients with elevated fecal cytokines at diagnosis. A logistic regression model identified high CXCL-5 messenger RNA abundance as the only predictor of persistent diarrhea. Conversely, fecal C difficile bacterial burden was not different in symptomatic and asymptomatic children and did not correlate with any clinical outcome measure.

CONCLUSIONS

Fecal inflammatory cytokines may be useful in distinguishing C difficile colonization from disease and identifying children with C difficile infection likely to have prolonged diarrhea.

Viral co-infections are common and are associated with higher bacterial burden in children with clostridium difficile infection

Clostridium difficile infections in children are increasing. In this cohort study, we enrolled 62 children with diarrhea and C difficile. We performed polymerase chain reaction assays to detect viral agents of gastroenteritis and quantify C difficile burden. Fifteen (24%) children diagnosed as having C difficile infection had a concomitant viral co-infection. These patients tended to be younger and had a higher C difficile bacterial burden than children with no viral co-infections (median difference = 565,957 cfu/mL; P = 0.011), but were clinically indistinguishable. The contribution of viral co-infection to C difficile disease in children warrants future investigation.

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.

Can we identify patients at high risk of recurrent Clostridium difficile infection?

Although most patients with Clostridium difficile infection (CDI) can be managed effectively with discontinuation of prescribed antibiotics and additional treatment with oral metronidazole or vancomycin, up to 25% experience disease recurrence, usually within 30 days of treatment. Failure to mount a systemic anti-toxin antibody response differentiates patients with CDI and recurrent CDI from symptomless carriers of toxinogenic C. difficile. The immunological senescence that accompanies ageing may lead to impaired immune responses to C. difficile and contribute to the significant association between advancing age and increased risk of CDI recurrence. Inadequate immunity may also explain why previous episodes of recurrence constitute a significant risk factor for further CDI recurrences. Other risk factors for recurrent CDI include concurrent use of antibiotics for non-C. difficile infections (which perpetuate the loss of colonization resistance), proton-pump inhibitors, and other gastric acid anti-secretory medications, prolonged hospitalization, and severe underlying illness (as reflected by a high Horn index score). Prominent risk factors have been examined to develop and validate a clinical prediction tool for recurrent CDI, with three factors (age >65 years, severe underlying disease (by the Horn index score), and continued use of antibiotics for non-CDI infections) being highly predictive of CDI recurrence. Such simple clinical prediction rules have the potential to identify patients at high risk of recurrent CDI, and can alert the treating physician to the need for prompt recognition, confirmatory diagnosis and treatment with regimens ideally designed to mitigate the risk of subsequent recurrences.

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.

Association between proton pump inhibitor therapy and Clostridium difficile infection in a meta-analysis

BACKGROUND & AIMS

In the past decade, there has been a growing epidemic of Clostridium difficile infection (CDI). During this time, use of proton pump inhibitors (PPIs) has increased exponentially. We evaluated the association between PPI therapy and the risk of CDI by performing a meta-analysis.

METHODS

We searched MEDLINE and 4 other databases for subject headings and text words related to CDI and PPI in articles published from 1990 to 2010. All observational studies that investigated the risk of CDI associated with PPI therapy and used CDI as an end point were considered eligible. Two investigators screened articles independently for inclusion criteria, data extraction, and quality assessment; disagreements were resolved based on consensus with a third investigator. Data were combined by means of a random-effects model and odds ratios were calculated. Subgroup and sensitivity analyses were performed based on study design and antibiotic use.

RESULTS

Thirty studies (25 case-control and 5 cohort) reported in 29 articles met the inclusion criteria (n = 202,965). PPI therapy increased the risk for CDI (odds ratio, 2.15, 95% confidence interval, 1.81-2.55), but there was significant heterogeneity in results among studies (P < .00001). This association remained after subgroup and sensitivity analyses, although significant heterogeneity persisted among studies.

CONCLUSIONS

PPI therapy is associated with a 2-fold increase in risk for CDI. Because of the observational nature of the analyzed studies, we were not able to study the causes of this association. Further studies are needed to determine the mechanisms by which PPI therapy might increase risk for CDI.

Clinical approach to severe Clostridium difficile infection: update for the hospital practitioner

The rising incidence of Clostridium difficile (C. difficile) infection or CDI is now a problem of pandemic proportions. The NAP1 hypervirulent strain of C. difficile is responsible for a majority of recent epidemics and the widespread use of fluoroquinolone antibiotics may have facilitated the selective proliferation of this strain. The NAP1 strain also is more likely to cause severe and fulminant colitis characterized by marked leukocytosis, renal failure, hemodynamic instability, and toxic megacolon. No single test suffices to diagnose severe CDI, instead; the clinician must rely on a combination of clinical acumen, laboratory testing, and radiologic and endoscopic modalities. Although oral vancomycin and metronidazole are considered standard therapies in the medical management of CDI, recently it has been demonstrated that vancomycin is the more effective antibiotic in cases of severe disease. Moreover, early surgical consultation is necessary in patients who do not respond to medical therapy or who demonstrate rising white blood cell counts or hemodynamic instability indicative of fulminant colitis. Subtotal colectomy with end ileostomy is the procedure of choice for fulminant colitis. When applied to select patients in a judicious and timely fashion, surgery can be a life-saving intervention. In addition to these therapeutic approaches, several investigational treatments including novel antibiotics, fecal bacteriotherapy and immunotherapy have shown promise in the care of patients with severe CDI.

Rapid diagnosis of Clostridium difficile infection by multiplex real-time PCR

The gold standards for the diagnosis of Clostridium difficile infections (CDIs) are the cytotoxicity assay and the toxigenic culture. However, both methods are time-consuming and the results are not available before 24-48 h. We developed and evaluated a multiplex in-house real-time polymerase chain reaction (PCR) assay for the simultaneous detection of toxigenic strains of C. difficile and the presumptive identification of the epidemic NAP1/027/BI strain from stools. Amplifications were performed using specific primers for tcdB and tcdC on an ABI Prism 7300 (Applied Biosystems). The detection of amplicons was done using TaqMan probes. The analytical sensitivity of the multiplex real-time PCR for detecting tcdB was estimated to 10 CFU/g of stools. This assay was assessed from 881 consecutive unformed stools from patients suspected of having CDI. The gold standard was the toxigenic culture for the diagnosis of CDI and PCR ribotyping for the identification of the NAP1/027/BI strain. The prevalence of positive toxigenic culture was 9.31%. Compared to the toxigenic culture, the sensitivity, specificity, and positive and negative predictive values were 86.59%, 97.43%, 78.02%, and 98.57%, respectively, for the real-time PCR and 70.73%, 100%, 100%, and 97.08%, respectively, for the cytotoxicity assay.

Spore-forming Bacilli and Clostridia in human disease

Many Gram-positive spore-forming bacteria in the Firmicute phylum are important members of the human commensal microbiota, which, in rare cases, cause opportunistic infections. Other spore-formers, however, have evolved to become dedicated pathogens that can cause a striking variety of diseases. Despite variations in disease presentation, the etiologic agent is often the spore, with bacterially produced toxins playing a central role in the pathophysiology of infection. This review will focus on the specific diseases caused by spores of the Clostridia and Bacilli.

Effects of inoculum, pH, and cations on the in vitro activity of fidaxomicin (OPT-80, PAR-101) against Clostridium difficile

The effects of the inoculum, pH, cation concentrations, and different lots of commercial media on the in vitro susceptibility of Clostridium difficile to fidaxomicin were examined. Of the factors evaluated, only pH alterations influenced the activity of fidaxomicin against C. difficile, noticeably reducing its activity at higher pH (> or =7.9).

Clostridium difficile infection: An overview of the disease and its pathogenesis, epidemiology and interventions

Clostridium difficile infection (CDI) is the primary cause of antibiotic-associated diarrhea and is a significant nosocomial disease. In the past ten years, variant toxin-producing strains of C. difficile have emerged, that have been associated with severe disease as well as outbreaks worldwide. This review summarizes current information on C. difficile pathogenesis and disease, and highlights interventions used to combat single and recurrent episodes of CDI.