A review of the economics of treating Clostridium difficile infection

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.

Lactobacillus pentosus Alleviates Lipopolysaccharide-Induced Neuronal Pyroptosis via Promoting BIRC3-Mediated Inactivation of NLRC4

Objective

Neurodegenerative disease is a common neurodegenerative disorder. Lactobacillus pentosus (L. pentosus) plays a neuron-protective role. This study aimed to investigate the effects of L. pentosus on neurodegenerative diseases.

Methods

Cells were treated with lipopolysaccharide (LPS) to establish neurodegenerative diseases model in vivo and with L. pentosus strain S-PT84. Reverse transcription-quantitative PCR (RT-qPCR) was applied to determine mRNA levels. Western blot was performed to detect protein expression. Cellular behaviors were detected using Cell Counting Kit-8 (CCK-8), flow cytometry, and TdT-mediated dUTP nick-end labeling (TUNEL) assay. The interaction between baculoviral IAP repeat containing 3 (BIRC3) and NLR family CARD domain containing 4 (NLRC4) was predicted by STING and verified by western blot.

Result

L. pentosus suppressed LPS-induced pyroptosis and promoted the cell viability of neurons. Additionally, L. pentosus suppressed the release of proinflammatory cytokines (interleukin 1 beta (IL-1β) and IL-18) and the protein expression of pyroptosis biomarkers (cleaved caspase1 (CL-CASP1) and N-terminal fragment gasdermin D (GSDMD-N)). Moreover, L. pentosus upregulated BIRC3, which induced the inactivation of NLRC4. However, BIRC3 knockdown alleviated the effects of L. pentosus and induced neuronal degeneration.

Conclusion

L. pentosus may play a neuron-protective role via regulating BIRC3/NLRC4 signaling pathways. Therefore, L. pentosus may be a promising strategy for neurodegenerative diseases.

Nitro-Group-Containing Thiopeptide Derivatives as Promising Agents to Target Clostridioides difficile

The US Centers for Disease Control and Prevention (CDC) lists Clostridioides difficile as an urgent bacterial threat. Yet, only two drugs, vancomycin and fidaxomicin, are approved by the FDA for the treatment of C. difficile infections as of this writing, while the global pipeline of new drugs is sparse at best. Thus, there is a clear and urgent need for new antibiotics against that organism. Herein, we disclose that AJ-024, a nitroimidazole derivative of a 26-membered thiopeptide, is a promising anti-C. difficile lead compound. Despite their unique mode of action, thiopeptides remain largely unexploited as anti-infective agents. AJ-024 combines potent in vitro activity against various strains of C. difficile with a noteworthy safety profile and desirable pharmacokinetic properties. Its time-kill kinetics against a hypervirulent C. difficile ribotype 027 and in vivo (mouse) efficacy compare favorably to vancomycin, and they define AJ-024 as a valuable platform for the development of new anti-C. difficile antibiotics.

Evaluation of Addition of Intravenous Metronidazole to Oral Vancomycin Therapy in Critically Ill Patients with Non-Fulminant Severe Clostridioides difficile Infection

BACKGROUND

Data on the impact of combination therapy (intravenous metronidazole [IV MTZ] plus oral vancomycin [PO VAN]) on clinical outcomes in intensive care unit (ICU) patients with severe non-fulminant Clostridioides difficile infection (CDI), including NAP1-positive samples, are lacking.

METHODS

Retrospective observational cohort of adult patients who developed CDI in the ICU diagnosed with severe non-fulminant CDI who received PO VAN. Patients with an order for IV MTZ started within 72 hours of PO VAN and who received at least 72 hours of combined therapy composed the combination therapy group. A subset of patients had stool samples collected for NAP1 testing. An additional subset was matched by Acute Physiology and Chronic Health Evaluation (APACHE) II scores. The primary outcome was inpatient all-cause mortality within 30 days of CDI diagnosis.

RESULTS

A total of 138 patients were included with 60 (43.5%) patients in the combination group. Compared with the PO VAN group, those in the combination group had higher white blood cell counts at diagnosis (15.9 [interquartile range (IQR) 10.2-21.1] vs 20.9 [IQR 16.2-29] cells/mm³ , p<0.001), respectively. Overall inpatient mortality was higher in the combination group, but 30-day mortality was not significantly different between groups (12.8% monotherapy vs 18.3% combination, p=0.371). This finding was the same for the 96 patients in the APACHE II-matched subgroup, 14.6% monotherapy versus 18.8% combination, p=0.785. NAP1 testing was completed in 42 patients; 11 were positive (26.2%). Patients who were NAP1 positive were more likely to receive IV MTZ (54.5% vs 19.4%, p=0.026).

CONCLUSION

Compared with PO VAN, combination therapy with IV MTZ was not associated with better clinical outcomes in severe non-fulminant CDI in ICU patients.

A new role for heat shock factor 27 in the pathophysiology of Clostridium difficile toxin B

Clostridiumdifficile (CD) is a common pathogen that causes severe gastrointestinal inflammatory diarrhea in patients undergoing antibiotic therapy. Its virulence derives from two toxins, toxin CD, A and B (TcdA and TcdB) (Borriello et al. Rev Infect Dis 12, Suppl 2: S185-191, 1990). Among the prime candidates for CD colonization are patients with cystic fibrosis (CF), who are routinely treated with antibiotics and frequently hospitalized. Indeed, ~50% of patients with CF are colonized with virulent forms of CD but do not exhibit diarrhea (Bauer et al. Clin Microbiol Infect 20: O446-O449, 2014; Binkovitz et al. Am J Roentgenol 172: 517-521, 199; Zemljic et al. Anaerobe 16: 527-532, 2010). We found that TcdB has global effects on colonic cells, including reducing the steady-state levels of sodium-proton exchange regulatory factors, reducing the levels of heat shock protein (Hsp) 27, and increasing the fraction of total Hsp27 bound to the cystic fibrosis transmembrane conductance regulator (CFTR). Also, since some mutations in CFTR seem to be protective, we asked whether CFTR is a target of TcdB. We show here that TcdB increases the maturation of CFTR and transiently increases its function. These combined effects promote increased surface expression of CFTR, resulting in a transient increase in Cl^- secretion. This increase is followed by a precipitous decline in both CFTR-dependent Cl^- secretion and transepithelial resistance (TER), suggesting a breakdown in the epithelial cells' tight junctions. We also found that overexpressing Hsp27 reverses some of the deleterious effects of TcdB, in particular preserving TER and therefore likely the maintenance of barrier function. Thus, our data suggest that Hsp27 plays a role in the diarrhea generated by CD infection and is a potential therapeutic target for treating this diarrhea.NEW & NOTEWORTHYClostridium difficile (CD) is a common pathogen that causes severe gastrointestinal inflammatory diarrhea in patients undergoing antibiotic therapy. We provide new evidence that heat shock protein (Hsp) 27 is one of the key players in CD pathology and that increasing Hsp27 can prevent the decrease in transepithelial resistance induced by toxin CD B, pointing the way for pharmacologic therapies for patients with chronic CD infection that can increase Hsp27 as a means to mitigate the effects of CD on gastrointestinal pathology.

Proteomic Signatures of Clostridium difficile Stressed with Metronidazole, Vancomycin, or Fidaxomicin

The anaerobic pathogen Clostridium difficile is of growing significance for the health care system due to its increasing incidence and mortality. As C. difficile infection is both supported and treated by antibiotics, a deeper knowledge on how antimicrobial agents affect the physiology of this important pathogen may help to understand and prevent the development and spreading of antibiotic resistant strains. As the proteomic response of a cell to stress aims at counteracting the harmful effects of this stress, it can be expected that the pattern of a pathogen’s responses to antibiotic treatment will be dependent on the antibiotic mechanism of action. Hence, every antibiotic treatment is expected to result in a specific proteomic signature characterizing its mode of action. In the study presented here, the proteomic response of C. difficile 630∆erm to vancomycin, metronidazole, and fidaxomicin stress was investigated on the level of protein abundance and protein synthesis based on 2D PAGE. The quantification of 425 proteins of C. difficile allowed the deduction of proteomic signatures specific for each drug treatment. Indeed, these proteomic signatures indicate very specific cellular responses to each antibiotic with only little overlap of the responses. Whereas signature proteins for vancomycin stress fulfil various cellular functions, the proteomic signature of metronidazole stress is characterized by alterations of proteins involved in protein biosynthesis and protein degradation as well as in DNA replication, recombination, and repair. In contrast, proteins differentially expressed after fidaxomicin treatment can be assigned to amino acid biosynthesis, transcription, cell motility, and the cell envelope functions. Notably, the data provided by this study hint also at so far unknown antibiotic detoxification mechanisms.

An Engineered Synthetic Biologic Protects Against Clostridium difficile Infection

Morbidity and mortality attributed to Clostridium difficile infection (CDI) have increased over the past 20 years. Currently, antibiotics are the only US FDA-approved treatment for primary C. difficile infection, and these are, ironically, associated with disease relapse and the threat of burgeoning drug resistance. We previously showed that non-toxin virulence factors play key roles in CDI, and that colonization factors are critical for disease. Specifically, a C. difficile adhesin, Surface Layer Protein A (SlpA) is a major contributor to host cell attachment. In this work, we engineered Syn-LAB 2.0 and Syn-LAB 2.1, two synthetic biologic agents derived from lactic acid bacteria, to stably and constitutively express a host-cell binding fragment of the C. difficile adhesin SlpA on their cell-surface. Both agents harbor conditional suicide plasmids expressing a codon-optimized chimera of the lactic acid bacterium's cell-wall anchoring surface-protein domain, fused to the conserved, highly adherent, host-cell-binding domain of C. difficile SlpA. Both agents also incorporate engineered biocontrol, obviating the need for any antibiotic selection. Syn-LAB 2.0 and Syn-LAB 2.1 possess positive biophysical and in vivo properties compared with their parental antecedents in that they robustly and constitutively display the SlpA chimera on their cell surface, potentiate human intestinal epithelial barrier function in vitro, are safe, tolerable and palatable to Golden Syrian hamsters and neonatal piglets at high daily doses, and are detectable in animal feces within 24 h of dosing, confirming robust colonization. In combination, the engineered strains also delay (in fixed doses) or prevent (when continuously administered) death of infected hamsters upon challenge with high doses of virulent C. difficile. Finally, fixed-dose Syn-LAB ameliorates diarrhea in a non-lethal model of neonatal piglet enteritis. Taken together, our findings suggest that the two synthetic biologics may be effectively employed as non-antibiotic interventions for CDI.

Fecal microbiota transplantation in the treatment of Clostridium difficile infection: state of the art and literature review

ABSTRACT Clostridium difficile infection is a common complication following intestinal dysbiosis caused by abusive antibiotic use. It presents medical importance due to the high rates of recurrence and morbidity. Fecal microbiota transplantation is an effective alternative for the treatment of recurrent and refractory C. difficile infection and consists of introducing the intestinal microbiota from a healthy donor into a patient with this infection. The exact physiological mechanism by which fecal microbiota transplantation alters the intestinal microbiota is not well established, but it is clear that it restores the diversity and structure of the microbiota by promoting increased resistance to colonization by C. difficile. Several routes of transplant administration are being studied and used according to the advantages presented. All forms of application had a high cure rate, and the colonoscopic route was the most used. No relevant complications and adverse events have been documented, and the cost-effectiveness over conventional treatment has proven advantageous. Despite its efficacy, it is not commonly used as initial therapy, and more studies are needed to establish this therapy as the first option in case of refractory and recurrent Clostridium difficileinfection.

Cost-Effectiveness of Competing Treatment Strategies for Clostridium difficile Infection: A Systematic Review

BACKGROUND Clostridium difficile infection (CDI) presents a substantial economic burden and is associated with significant morbidity. While multiple treatment strategies have been evaluated, a cost-effective management strategy remains unclear. OBJECTIVE We conducted a systematic review to assess cost-effectiveness analyses of CDI treatment and to summarize key issues for clinicians and policy makers to consider. METHODS We searched PubMed and 5 other databases from inception to August 2016. These searches were not limited by study design or language of publication. Two reviewers independently screened the literature, abstracted data, and assessed methodological quality using the Drummond and Jefferson checklist. We extracted data on study characteristics, type of CDI, treatment characteristics, and model structure and inputs. RESULTS We included 14 studies, and 13 of these were from high-income countries. More than 90% of these studies were deemed moderate-to-high or high quality. Overall, 6 studies used a decision-tree model and 7 studies used a Markov model. Cost of therapy, time horizon, treatment cure rates, and recurrence rates were common influential factors in the study results. For initial CDI, fidaxomicin was a more cost-effective therapy than metronidazole or vancomycin in 2 of 3 studies. For severe initial CDI, 2 of 3 studies found fidaxomicin to be the most cost-effective therapy. For recurrent CDI, fidaxomicin was cost-effective in 3 of 5 studies, while fecal microbiota transplantation (FMT) by colonoscopy was consistently cost-effective in 4 of 4 studies. CONCLUSIONS The cost-effectiveness of fidaxomicin compared with other pharmacologic therapies was not definitive for either initial or recurrent CDI. Despite its high cost, FMT by colonoscopy may be a cost-effective therapy for recurrent CDI. A consensus on model design and assumptions are necessary for future comparison of CDI treatment. Infect Control Hosp Epidemiol 2018;39:412-424.

Comprehensive Redox Profiling of the Thiol Proteome of Clostridium difficile

The strictly anaerobic bacterium C. difficile has become one of the most problematic hospital acquired pathogens and a major burden for health care systems. Although antibiotics work effectively in most C. difficile infections (CDIs), their detrimental effect on the intestinal microbiome paves the way for recurrent episodes of CDI. To develop alternative, non-antibiotics-based treatment strategies, deeper knowledge on the physiology of C. difficile, stress adaptation mechanisms and regulation of virulence factors is mandatory. The focus of this work was to tackle the thiol proteome of C. difficile and its stress-induced alterations, because recent research has reported that the amino acid cysteine plays a central role in the metabolism of this pathogen. We have developed a novel cysteine labeling approach to determine the redox state of protein thiols on a global scale. Applicability of this technique was demonstrated by inducing disulfide stress using the chemical diamide. The method can be transferred to any kind of redox challenge and was applied in this work to assess the effect of bile acids on the thiol proteome of C. difficile We present redox-quantification for more than 1,500 thiol peptides and discuss the general difficulty of redox analyses of peptides possessing more than a single cysteine residue. The presented method will be especially useful not only when determining redox status, but also for providing information on protein quantity. Additionally, our comprehensive data set reveals protein cysteine sites particularly susceptible to oxidation and builds a groundwork for redox proteomics studies in C. difficile.

Adherence to clinical practice guidelines for the management of Clostridium difficile infection in Japan: a multicenter retrospective study

This study was conducted to investigate the adherence to clinical practice guidelines (CPGs) for Clostridium difficile infection (CDI). A retrospective multicenter observational study was conducted via chart review at four teaching hospitals in Japan from April 2012 through September 2013. CDI was diagnosed based on positive identification of CD toxin by enzyme immunoassay testing. CDI patients were divided into non-severe and severe groups according to the severity criteria of four published guidelines (SHEA/IDSA 2010, ACG 2013, ESCMID 2009, HPA/DH 2008). Three parameters were assessed in association with disease severity: adherence to treatment guidelines, prognosis, and relapse rate. In total, 170 patients were diagnosed with CDI (1.04 cases per 10,000 patient-days). The 30-day all-cause mortality and recurrence rates were 13% and 14%, respectively. CPGs adherence ranged from 52% to 70% in the non-severe group and from 8.5 to 23% in the severe group (P < 0.01). Among severe CDI patients, no significant difference in mortality or recurrence was found between the patients whose treatments adhered and did not adhere to the CPGs. CPGs adherence was low, especially for patients with severe CDI. Improved guideline adherence and more accurate definitions of severity based on prognosis are needed for appropriate CDI management.

A Comprehensive Study of Costs Associated With Recurrent Clostridium difficile Infection

BACKGROUND Clostridium difficile infection (CDI) is the most common healthcare-associated infection and is associated with considerable morbidity. Recurrent CDI is a key contributing factor to this morbidity. Despite an estimated 83,000 recurrences annually in the United States, there are few accurate estimates of costs associated with recurrent CDI. OBJECTIVE We performed this study (1) to identify the health consequences of recurrent CDI including need for repeat hospitalization, intensive care unit (ICU) stay, and surgery; (2) to determine costs associated with recurrent CDI and identify determinants of such costs; and (3) to compare the outcomes and costs of recurrent CDI to those who develop reinfection. METHODS We identified all patients with confirmed recurrent CDI between January to December 2013 at a single referral center. Healthcare burden associated with recurrence including diagnostic testing, pharmacologic treatment, and inpatient and outpatient healthcare visits were identified in the 12 months following the first recurrence. Total healthcare costs were calculated, and the predictors of high healthcare utilization were identified. RESULTS Our study population included 98 patients with recurrent CDI. The median interval between the initial infection and recurrence was 37 days. The mean age of the cohort was 67 years, two-thirds were women (62%), and the mean Charlson index was 8.6. During the year following the first recurrence of CDI, each patient underwent a mean of 4.4 stool C. difficile toxin tests and received a mean of 2.5 prescriptions for oral vancomycin (range, 0-6). Most patients (84%) with recurrence had a CDI-related hospitalization, and 6% underwent colectomy. The mean total CDI-associated cost was $34,104 per patient, with hospitalization costs accounting for 68%, surgery 20%, and drug treatment 8% of this cost, respectively. Extrapolating to the United States overall, we estimate an annual cost of $2.8 billion related to recurrent CDI. CONCLUSION Recurrent CDI is associated with considerable morbidity and cost. Infect Control Hosp Epidemiol 2017;38:196-202.

Rapid change of fecal microbiome and disappearance of Clostridium difficile in a colonized infant after transition from breast milk to cow milk

BACKGROUND

Clostridium difficile is the most common known cause of antibiotic-associated diarrhea. Upon the disturbance of gut microbiota by antibiotics, C. difficile establishes growth and releases toxins A and B, which cause tissue damage in the host. The symptoms of C. difficile infection disease range from mild diarrhea to pseudomembranous colitis and toxic megacolon. Interestingly, 10-50 % of infants are asymptomatic carriers of C. difficile. This longitudinal study of the C. difficile colonization in an infant revealed the dynamics of C. difficile presence in gut microbiota.

METHODS

Fifty fecal samples, collected weekly between 5.5 and 17 months of age from a female infant who was an asymptomatic carrier of C. difficile, were analyzed by 16S rRNA gene sequencing.

RESULTS

Colonization switching between toxigenic and non-toxigenic C. difficile strains as well as more than 100,000-fold fluctuations of C. difficile counts were observed. C. difficile toxins were detected during the testing period in some infant stool samples, but the infant never had diarrhea. Although fecal microbiota was stable during breast feeding, a dramatic and permanent change of microbiota composition was observed within 5 days of the transition from human milk to cow milk. A rapid decline and eventual disappearance of C. difficile coincided with weaning at 12.5 months. An increase in the relative abundance of Bacteroides spp., Blautia spp., Parabacteroides spp., Coprococcus spp., Ruminococcus spp., and Oscillospira spp. and a decrease of Bifidobacterium spp., Lactobacillus spp., Escherichia spp., and Clostridium spp. were observed during weaning. The change in microbiome composition was accompanied by a gradual increase of fecal pH from 5.5 to 7.

CONCLUSIONS

The bacterial groups that are less abundant in early infancy, and that increase in relative abundance after weaning, likely are responsible for the expulsion of C. difficile.

CRISPR Diversity and Microevolution in Clostridium difficile

Virulent strains of Clostridium difficile have become a global health problem associated with morbidity and mortality. Traditional typing methods do not provide ideal resolution to track outbreak strains, ascertain genetic diversity between isolates, or monitor the phylogeny of this species on a global basis. Here, we investigate the occurrence and diversity of clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated genes (cas) in C. difficile to assess the potential of CRISPR-based phylogeny and high-resolution genotyping. A single Type-IB CRISPR-Cas system was identified in 217 analyzed genomes with cas gene clusters present at conserved chromosomal locations, suggesting vertical evolution of the system, assessing a total of 1,865 CRISPR arrays. The CRISPR arrays, markedly enriched (8.5 arrays/genome) compared with other species, occur both at conserved and variable locations across strains, and thus provide a basis for typing based on locus occurrence and spacer polymorphism. Clustering of strains by array composition correlated with sequence type (ST) analysis. Spacer content and polymorphism within conserved CRISPR arrays revealed phylogenetic relationship across clades and within ST. Spacer polymorphisms of conserved arrays were instrumental for differentiating closely related strains, e.g., ST1/RT027/B1 strains and pathogenicity locus encoding ST3/RT001 strains. CRISPR spacers showed sequence similarity to phage sequences, which is consistent with the native role of CRISPR-Cas as adaptive immune systems in bacteria. Overall, CRISPR-Cas sequences constitute a valuable basis for genotyping of C. difficile isolates, provide insights into the micro-evolutionary events that occur between closely related strains, and reflect the evolutionary trajectory of these genomes.

The protein inventory of Clostridium difficile grown in complex and minimal medium

The intestinal pathogen Clostridium difficile is causing an increasing number of infections often characterized by severity and high relapse rates. Profound knowledge of the physiology of the pathogen could help to develop new treatment strategies. Proteomics, a valuable tool to study bacterial physiology, was used in this work to establish a benchmark proteome of reference strain C. difficile 630Δerm with MS-based details on all identified proteins. Our elaborate annotation and visualization of C. difficile 630Δerm 3764 ORFs will serve as a valuable base for researchers having to evaluate global expression studies. To exemplify expression variability, protein expression of late exponentially growing cells in complex brain-heart infusion medium and C. difficile minimal medium was compared. Noteworthy results of this comparison are as follows: (i) the higher expression of enzymes for the biosynthesis of some vitamins and purine and (ii) downregulation of proteins involved in butanoate fermentation in C. difficile minimal medium. However, the abundance of proteins involved in DNA metabolism, protein synthesis, and the cell envelope showed no variation between the two growth media.

Cost of hospital management of Clostridium difficile infection in United States-a meta-analysis and modelling study

Background

Clostridium difficile infection (CDI) is the leading cause of infectious nosocomial diarrhoea but the economic costs of CDI on healthcare systems in the US remain uncertain.

Methods

We conducted a systematic search for published studies investigating the direct medical cost associated with CDI hospital management in the past 10 years (2005–2015) and included 42 studies to the final data analysis to estimate the financial impact of CDI in the US. We also conducted a meta-analysis of all costs using Monte Carlo simulation.

Results

The average cost for CDI case management and average CDI-attributable costs per case were $42,316 (90 % CI: $39,886, $44,765) and $21,448 (90 % CI: $21,152, $21,744) in 2015 US dollars. Hospital-onset CDI-attributable cost per case was $34,157 (90 % CI: $33,134, $35,180), which was 1.5 times the cost of community-onset CDI ($20,095 [90 % CI: $4991, $35,204]). The average and incremental length of stay (LOS) for CDI inpatient treatment were 11.1 (90 % CI: 8.7–13.6) and 9.7 (90 % CI: 9.6–9.8) days respectively. Total annual CDI-attributable cost in the US is estimated US$6.3 (Range: $1.9–$7.0) billion. Total annual CDI hospital management required nearly 2.4 million days of inpatient stay.

Conclusions

This review indicates that CDI places a significant financial burden on the US healthcare system. This review adds strong evidence to aid policy-making on adequate resource allocation to CDI prevention and treatment in the US. Future studies should focus on recurrent CDI, CDI in long-term care facilities and persons with comorbidities and indirect cost from a societal perspective. Health-economic studies for CDI preventive intervention are needed.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-1786-6) contains supplementary material, which is available to authorized users.

Recurrent Clostridium difficile infection in intensive care unit patients

BACKGROUND

The purpose of this study was to assess the 12-week cumulative incidence of recurrent Clostridium difficile infection (rCDI) and identify risk factors for rCDI in patients that acquired index C difficile infection (CDI) while in the intensive care unit (ICU).

METHODS

This retrospective single-center cohort study reviewed adult patients from 6 different ICUs who developed a CDI between February 2010 and September 2013.

RESULTS

Out of 162 included ICU patients, 34 experienced rCDI. Risk of rCDI was higher in the ICU versus non-ICU group (21% vs 17%, P = .03). The incidence of rCDI was highest in the surgical intensive care unit (SICU) at 43.8%. A multivariable logistic regression model was constructed and identified 5 significant risk factors for rCDI: previous CDI (odds ratio [OR], 8.03; 95% confidence interval [CI], 1.90-34.02; P = .005), log10 ICU length of stay in days (OR, 3.67; 95% CI, 1.13-11.85; P = .03), acquisition of CDI in the medical intensive care unit (MICU) (OR, 5.35; 95% CI, 1.60-17.85; P = .006) or SICU (OR, 15.30; 95% CI, 4.09-57.23; P < .001), and chronic obstructive pulmonary disease (COPD) (OR, 3.55; 95% CI, 1.41-8.94; P = .007).

CONCLUSION

ICU adults had a significantly higher 12-week incidence of rCDI than non-ICU patients. Risk factors for rCDI after acquisition of infection in an ICU include MICU and SICU patients, previous CDI, COPD, and length of stay.

Clostridium Difficile Infection from a Surgical Perspective

BACKGROUND

The incidence and the severity of Clostridium difficile infection (CDI) have increased significantly over the last decade, especially in high-risk populations such as patients with inflammatory bowel disease (IBD). Surgeons must be able to both identify and minimize the risk of CDI in their own surgical patients and determine which CDI patients will benefit from surgery.

PURPOSE

We sought to define the risk factors, compare the treatment options, define the surgical indications, and identify factors that affect surgical outcomes for CDI based on the currently available literature.

RESULTS

Antibiotic use, exposure to the C. difficile bacteria, IBD, and higher levels of co-morbidity are all risk factors for CDI. The majority of CDI can be treated with antibiotics. Severe or fulminant colitis, however, has a high potential for poor outcome, but experience and some data suggest a lower mortality rate with colectomy rather than with continued medical treatment. Open total abdominal colectomy with end ileostomy is typically the preferred surgical strategy. It is often difficult to determine which patients will fail medical management as some may not manifest clinical signs of severe infection. Surrogate parameters of failure of medical therapy include respiratory and/or renal insufficiency, age greater than 60 years, peripheral vascular disease, congestive heart failure, and coagulopathy, all of which have been associated with worse surgical outcomes. Evidence suggests that in appropriately selected patients, colectomy performed before the development of shock requiring vasopressors, respiratory failure, renal failure, multi-organ dysfunction, and mental status changes may reduce mortality of the most severe forms of colitis. For less severe or recurrent presentations, creation of a loop ileostomy with intra-operative colonic lavage, fecal microbiota transfer, and C. difficile vaccinations are being discussed but have only been studied in small case-controlled series.

CONCLUSIONS

Prevention, containment, and non-surgical treatment are the cornerstone of management for CDI. However, the most severe forms with toxic colitis benefit from involvement of a surgical team. Swift open total abdominal colectomy with end ileostomy in patients with severe or fulminant C. difficile colitis has the best chance to reduce mortality if it is not delayed until shock, end organ damage, vasopressor requirement, mental status changes develop. Less aggressive approaches may be appropriate for milder and refractory forms but require further study before their applicability can be determined.

Identification of Recurrent Clostridium difficile Infection Using Administrative Codes: Accuracy and Implications for Surveillance

OBJECTIVE

To develop an algorithm using administrative codes, laboratory data, and medication data to identify recurrent Clostridium difficile infection (CDI) and to examine the sensitivity, specificity, positive and negative predictive values, and performance of this algorithm.

METHODS

We identified all patients with 2 or more International Classification of Diseases, Ninth Edition, Clinical Modification (ICD-9-CM) codes for CDI (008.45) from January 1 through December 31, 2013. Information on number of diagnosis codes, stool toxin assays (enzyme immunoassay or polymerase chain reaction), and unique prescriptions for metronidazole and vancomycin was identified. Logistic regression was used to identify independent predictors of recurrent CDI and a predictive model was developed.

RESULTS

A total of 591 patients with at least 2 ICD-9 codes for CDI were included (median age, 66 years). The derivation cohort consisted of 157 patients among whom 43 (27%) had recurrent CDI. Presence of 3 or more ICD-9 codes for CDI (odds ratio, 2.49), 2 or more stool tests (odds ratio, 2.88), and 2 or more prescriptions for vancomycin (odds ratio, 5.87) were independently associated with confirmed recurrent CDI. A classifier incorporating 2 or more prescriptions for vancomycin and either 2 or more stool tests or 3 or more ICD-9-CM codes had a positive predictive value of 41% and negative predictive value of 90%. The area under the receiver operating characteristic curve for this combined classifier was modest (0.69).

CONCLUSION

Identification of recurrent episodes of CDI in administrative data poses challenges. Accurate assessment of burden requires individual case review to confirm diagnosis.

Infect Control Hosp Epidemiol 2015;36(8):893–898

The Clostridium difficile Protease Cwp84 Modulates both Biofilm Formation and Cell-Surface Properties

Clostridium difficile is responsible for 15-20% of antibiotic-associated diarrheas, and nearly all cases of pseudomembranous colitis. Among the cell wall proteins involved in the colonization process, Cwp84 is a protease that cleaves the S-layer protein SlpA into two subunits. A cwp84 mutant was previously shown to be affected for in vitro growth but not in its virulence in a hamster model. In this study, the cwp84 mutant elaborated biofilms with increased biomass compared with the parental strain, allowing the mutant to grow more robustly in the biofilm state. Proteomic analyses of the 630Δerm bacteria growing within the biofilm revealed the distribution of abundant proteins either in cell surface, matrix or supernatant fractions. Of note, the toxin TcdA was found in the biofilm matrix. Although the overall proteome differences between the cwp84 mutant and the parental strains were modest, there was still a significant impact on bacterial surface properties such as altered hydrophobicity. In vitro and in vivo competition assays revealed that the mutant was significantly impaired for growth only in the planktonic state, but not in biofilms or in vivo. Taken together, our results suggest that the phenotypes in the cwp84 mutant come from either the accumulation of uncleaved SlpA, or the ability of Cwp84 to cleave as yet undetermined proteins.