Clostridium difficile colitis

AsnB is responsible for peptidoglycan precursor amidation in Clostridium difficile in the presence of vancomycin

Clostridium difficile 630 possesses a cryptic but functional gene cluster vanG _Cd homologous to the vanG operon of Enterococcus faecalis. Expression of vanG _Cd in the presence of subinhibitory concentrations of vancomycin is accompanied by peptidoglycan amidation on the meso-DAP residue. In this paper, we report the presence of two potential asparagine synthetase genes named asnB and asnB2 in the C. difficile genome whose products were potentially involved in this peptidoglycan structure modification. We found that asnB expression was only induced when C. difficile was grown in the presence of vancomycin, yet independently from the vanG _Cd resistance and regulation operons. In addition, peptidoglycan precursors were not amidated when asnB was inactivated. No change in vancomycin MIC was observed in the asnB mutant strain. In contrast, overexpression of asnB resulted in the amidation of most of the C. difficile peptidoglycan precursors and in a weak increase of vancomycin susceptibility. AsnB activity was confirmed in E. coli. In contrast, the expression of the second asparagine synthetase, AsnB2, was not induced in the presence of vancomycin. In summary, our results demonstrate that AsnB is responsible for peptidoglycan amidation of C. difficile in the presence of vancomycin.

Clostridioides difficile Infection in the Stem Cell Transplant and Hematologic Malignancy Population

Clostridioides difficile infection (CDI) is common in the stem cell transplant (SCT) and hematologic malignancy (HM) population and mostly occurs in the early posttransplant period. Treatment of CDI in SCT/HM is the same as for the general population, with the exception that fecal microbiota transplant (FMT) has not been widely adopted because of safety concerns. Several case reports, small series, and retrospective studies have shown that FMT is effective and safe. A randomized controlled trial of FMT for prophylaxis of CDI in SCT patients is underway. In addition, an abundance of novel therapeutics for CDI is currently in development.

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.

Targeting gut microbiome: A novel and potential therapy for autism

Autism spectrum disorder (ASD) is a severely neurodevelopmental disorder that impairs a child's ability to communicate and interact with others. Children with neurodevelopmental disorder, including ASD, are regularly affected by gastrointestinal problems and dysbiosis of gut microbiota. On the other hand, humans live in a co-evolutionary association with plenty of microorganisms that resident on the exposed and internal surfaces of our bodies. The microbiome, refers to the collection of microbes and their genetic material, confers a variety of physiologic benefits to the host in many key aspects of life as well as being responsible for some diseases. A large body of preclinical literature indicates that gut microbiome plays an important role in the bidirectional gut-brain axis that communicates between the gut and central nervous system. Moreover, accumulating evidences suggest that the gut microbiome is involved in the pathogenesis of ASD. The present review introduces the increasing evidence suggesting the reciprocal interaction network among microbiome, gut and brain. It also discusses the possible mechanisms by which gut microbiome influences the etiology of ASD via altering gut-brain axis. Most importantly, it highlights the new findings of targeting gut microbiome, including probiotic treatment and fecal microbiota transplant, as novel and potential therapeutics for ASD diseases.

Antibiotic Regimen after a Total Abdominal Colectomy with Ileostomy for Fulminant Clostridium difficile Colitis: A Multi-Institutional Study

BACKGROUND

Fulminant Clostridium difficile colitis (fCDC) is a highly lethal disease with mortality rates ranging between 12% and 80%. Although often these patients require a total abdominal colectomy (TAC) with ileostomy, there is no established management protocol for post-operative antibiotics. In this study we aim to make some recommendations for post-operative antibiotic usage, while describing the practice across different institutions.

METHODS

Multi-institutional retrospective case series including fCDC patients who underwent a TAC between January 1, 2007, and June 30, 2012. We first analyzed the complete cohort and consecutively performed a survivor analysis, comparing different antibiotic regimens. Additionally we stratified by time interval (antibiotics for ≤7 d, or ≥8 d). Primary outcome was in-hospital mortality. Additional secondary outcomes included hospital length of stay (HLOS), ICU LOS, number of ventilator-free days, and occurrence of intra-abdominal complications (proctitis, abscess, sepsis, etc.).

RESULTS

A total of 100 fCDC patients that underwent a TAC were included across five institutions. Four different antibiotic regimens were compared; A (metronidazole IV+vancomycin PO), B (metronidazole IV), C (metronidazole IV+vanco PO and PR), and D (metronidazole IV+vancomycin PR). The combination of IV metronidazole with or without PO vancomycin showed superior outcomes in terms of a shorter ICU length of stay and more ventilator-free days. However, when comparing metronidazole alone vs. metronidazole and any combination of vancomycin, no significant differences were found. Neither the addition of vancomycin enema, nor the time interval changed outcomes.

CONCLUSION

Patients, after a TAC for fCDC, may be placed on either IV metronidazole or PO vancomycin depending upon local antibiograms, and proctitis may be treated with the addition of a vancomycin enema (PR). There was no data to support routine treatment of more than 7 d.

Clostridium difficile Infections after Blunt Trauma: A Different Patient Population?

BACKGROUND

The epidemiology of Clostridium difficile-associated infection (CDI) has changed, and it is evident that susceptibility is related not only to exposures and bacterial potency, but host factors as well. Several small studies have suggested that CDI after trauma is associated with a different patient phenotype. The purpose of this study was to examine and describe the epidemiologic factors associated with C. difficile in blunt trauma patients without traumatic brain injury using the Trauma-Related Database as a part of the "Inflammation and Host Response to Injury" (Glue Grant) and the University of Florida Integrated Data Repository.

METHODS

Previously recorded baseline characteristics, clinical data, and outcomes were compared between groups (67 C. difficile and 384 uncomplicated, 813 intermediate, and 761 complicated non-C. difficile patients) as defined by the Glue Grant on admission and at days seven and 14.

RESULTS

The majority of CDI patients experienced complicated or intermediate clinical courses. The mean ages of all cohorts were less than 65 y and CDI patients were significantly older than uncomplicated patients without CDI. The CDI patients had increased days in the hospital and on the ventilator, as well as significantly higher new injury severity scores (NISS), and a greater percentage of patients with NISS >34 points compared with non-CDI patients. They also had greater Marshall and Denver multiple organ dysfunction scores than non-CDI uncomplicated patients, and greater creatinine, alkaline phosphatase, neutrophil count, lactic acid, and PiO2:FiO2 compared with all non-CDI cohorts on admission. In addition, the CDI patients had higher glucose concentrations and base deficit from uncomplicated patients and greater leukocytosis than complicated patients on admission. Several of these changes persisted to days seven and 14.

CONCLUSION

Analysis of severe blunt trauma patients with C. difficile, as compared with non-CDI patients, reveals evidence of increased inflammation, immunosuppression, worse acute kidney injury, higher NISS, greater days in the hospital and on the ventilator, higher organ injury scores, and prolonged clinical courses. This supports reports of an increased prevalence of CDI in a younger population not believed previously to be at risk. This unique population may have specific genomic or inflammation-related risk factors that may play more important roles in disease susceptibility. Prospective analysis may allow early identification of at-risk patients, creation of novel therapeutics, and improved understanding of how and why C. difficile colonization transforms into infection after severe blunt trauma.

Surgical Management of Severe Colitis in the Intensive Care Unit

Severe colitis, an umbrella encompassing several entities, is one of the most common acute gastrointestinal disorders resulting in critical illness. Clostridium difficile infection is responsible for the majority of nosocomial diarrhea with fulminant C difficile colitis (CDC) carrying a high mortality. Optimal outcomes can be achieved by early identification and treatment of fulminant CDC, with appropriate surgical intervention when indicated. Ischemic colitis, on the other hand, is uncommon with a range of etiological factors including abdominal aortic surgery, inotropic drugs, rheumatoid diseases, or often no obvious triggering factor. Most cases resolve with nonsurgical management; however, prompt recognition of full-thickness necrosis and gangrene is crucial for good patient outcomes. Fulminant colitis is a severe disease secondary to progressive ulcerative colitis with systemic deterioration. Surgical intervention is indicated for hemorrhage, perforation, or peritonitis and failure of medical therapy to control the disease. Although, failure of medical management is the most common indication, it can be difficult to define objectively and requires a collaborative multidisciplinary approach. This article proposes some simple management algorithms for these clinical entities, with a focus on critically ill patients.

Fulminant colitis

Fulminant colitis is an ill-defined entity that is usually viewed as the most severe form of uncomplicated acute colitis. It usually occurs in the course of ulcerative colitis and infectious colitis, but can also be seen in other forms of colitis. Every patient with clinical criteria for severe or fulminant colitis should be approached in a systematic way, based on two premises - intense medical treatment and early surgery in non-responders.

A genomic analysis of Clostridium difficile infections in blunt trauma patients

BACKGROUND

Evidence demonstrates that susceptibility to Clostridium difficile infection is related to host risk factors as much as bacterial potency. Using blood leukocyte genome-wide expression patterns of severe blunt trauma patients obtained by the National Institute of General Medical Sciences-sponsored Glue Grant Inflammation and the Host Response to Injury, we examined leukocyte genomic profiles of patients with C. difficile infection to determine preinfection and postinfection gene expression changes.

METHODS

The genomic responses of 21 severe trauma patients were analyzed (5 C. difficile, 16 controls matched for age and severity of injury). After elimination of probe sets whose expression was below baseline or were unchanged, remaining probe sets underwent hierarchical clustering and principal component analysis. Molecular pathways were generated through Ingenuity Pathways Analysis.

RESULTS

Supervised analysis demonstrated 118 genes whose expression in patients with C. difficile infection varied before and after their infection. Supervised analysis comparing patients with C. difficile infection with matched non-C. difficile patients before infection suggested that the expression of 501 genes were different in the two groups with up to 87% class prediction (p < 0.05). Many of these genes are related to cell-mediated immune responses, signaling, and interaction.

CONCLUSION

Genomic analysis of severe blunt trauma patients reveals a distinct leukocyte expression profile of C. difficile both before and after infection. We conclude that an association may exist between a severe trauma patient's leukocyte genomic expression profile and subsequent susceptibility to C. difficile infection. Further prospective expression analysis of this C. difficile population may reveal potential therapeutic interventions and allow early identification of C. difficile-susceptible patients.

LEVEL OF EVIDENCE

Prognostic/diagnostic study, level III.

Secular trends in the epidemiology of Clostridium difficile infection (CDI): relationship with alcohol gel and antimicrobial usage in a hospital

BACKGROUND

Clostridium difficile-associated diarrhea (CDAD) has shown increasing incidence, morbidity, and mortality in recent years. We assessed the number of CDAD tests requested, CDAD positivity rates, the use of alcohol-based hand rubs, and antimicrobial utilization.

METHODS

We collected information on every adult patient (>18 years) who developed diarrhea and had a positive stool test for C. difficile toxin from June 2005 to December 2009 at a tertiary care hospital. A time-series analysis was performed using monthly data on the incidence of C. difficile infection (CDI) (i.e., cases of infection per 1000 patient-days), as well as the consumption of alcohol-based hand rubs (in liters/1000-patient days) and antibiotics (in defined daily doses per 1000 patient-days).

RESULTS

The mean number of annual requests for C. difficile tests was 1031, and the rates per 1000 patient-days for each year from 2005 to 2009 were 0.30, 0.46, 0.39, 0.31, and 0.40 overall in the hospital, and 0.18, 0.10, 0.53, 0.38, and 0.37 in the intensive care unit (ICU). The use of alcohol-based hand rubs per 1000 patient-days increased from 37.4 to 73.0, and from 41.5 to 129.4 in the hospital and in the ICU, respectively.

CONCLUSIONS

The incidence of CDI in the hospital and ICU remained low, despite the increased use of alcohol-based hand rubs and antimicrobials.

Recent changes in Clostridium difficile infection

Clostridium difficile is the main cause of nosocomial diarrhea. Diarrhea associated with C. difficile has increased incidence, morbidity, and mortality in the last few years. The major related risk factors include use of antibiotics, elderly patients and prolonged hospital stay. Many patients receive combinations of antibiotics or multiple antibiotics, which represents the main risk to develop diarrhea associated to C. difficile or its recurrence. Therefore, interventions to improve antibiotic prescribing, as well as compliance with infection control measures can reduce hospital-acquired C. difficile infections. This review addresses the epidemiological changes in C. difficile disease and its treatment.

Clostridium difficile infection and proton pump inhibitors

PURPOSE OF REVIEW

Clostridium difficile is an intestinal infection associated with antibiotic use, commonly seen in patients with chronic medical issues. The purpose of this review is to discuss the association of C. difficile-associated diarrhea with use of proton pump inhibitors.

RECENT FINDINGS

Multiple medical factors predispose patients to C. difficile-associated diarrhea. Proton pump inhibitors, commonly used for gastric acid suppression, have been shown to have an association with C. difficile-associated diarrhea in both the outpatient and hospital setting. C. difficile-associated diarrhea also has been reported in the pediatric age range linked with proton pump inhibitor use.

SUMMARY

An association exists between C. difficile infection and proton pump inhibitor use. Treatment options exist for C. difficile-associated diarrhea, although judicious use of proton pump inhibitors and antibiotics, emphasis on hand washing, and appropriate use of patient isolation should be implemented as well.

Using machine-learned bayesian belief networks to predict perioperative risk of clostridium difficile infection following colon surgery

BACKGROUND

Clostridium difficile (C-Diff) infection following colorectal resection is an increasing source of morbidity and mortality.

OBJECTIVE

We sought to determine if machine-learned Bayesian belief networks (ml-BBNs) could preoperatively provide clinicians with postoperative estimates of C-Diff risk.

METHODS

We performed a retrospective modeling of the Nationwide Inpatient Sample (NIS) national registry dataset with independent set validation. The NIS registries for 2005 and 2006 were used for initial model training, and the data from 2007 were used for testing and validation. International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) codes were used to identify subjects undergoing colon resection and postoperative C-Diff development. The ml-BBNs were trained using a stepwise process. Receiver operating characteristic (ROC) curve analysis was conducted and area under the curve (AUC), positive predictive value (PPV), and negative predictive value (NPV) were calculated.

RESULTS

From over 24 million admissions, 170,363 undergoing colon resection met the inclusion criteria. Overall, 1.7% developed postoperative C-Diff. Using the ml-BBN to estimate C-Diff risk, model AUC is 0.75. Using only known a priori features, AUC is 0.74. The model has two configurations: a high sensitivity and a high specificity configuration. Sensitivity, specificity, PPV, and NPV are 81.0%, 50.1%, 2.6%, and 99.4% for high sensitivity and 55.4%, 81.3%, 3.5%, and 99.1% for high specificity. C-Diff has 4 first-degree associates that influence the probability of C-Diff development: weight loss, tumor metastases, inflammation/infections, and disease severity.

CONCLUSIONS

Machine-learned BBNs can produce robust estimates of postoperative C-Diff infection, allowing clinicians to identify high-risk patients and potentially implement measures to reduce its incidence or morbidity.

[Intrahospital mortality in patients with Clostridium difficile-associated diarrhea infection]

BACKGROUND

Clostridium difficile (C. difficile) is a gram-positive anaerobic bacillus capable of producing diarrhea or colitis in the hospitalized patient, particularly in those exposed to the use of antibiotics, and 6% to 38% mortality in patients with C. difficile-associated diarrhea (CDAD) has been described.

AIMS

To determine the hospital death rate in patients presenting with CDAD. As a secondary aim, hospital stay and risk factors for unfavorable outcome were recorded.

METHODS

A retrospective cohort study was carried out. The case records of hospitalized patients presenting with diarrhea and that tested positive for C. difficile through toxin A and B assays were reviewed. The number of non-surviving patients that presented with CDAD during hospitalization was recorded along with the principal factors associated with the worst outcome.

RESULTS

Of the 66 patients enrolled in the study, 6 (9,1%) died during their hospitalization. The median age was lower in the group of surviving patients than in the group of non-surviving patients, with 51,5 years (range 36 to 66,75) and 81,5 years (range 69,5 to 83,25), respectively (p=0,002). Hospital stay was 32,50 days (range 8,25 to 64,25) in the group of non-surviving patients and was 6,5 days (range 4 to 15,75) (p=0,045) in the group with no deaths.

CONCLUSIONS

The elevated mortality found in the hospitalized CDAD patients in the Intensive Care Unit makes the maintenance of strict surveillance in this population imperative so there can be opportune detection and treatment.

Clinical predictors of fulminant colitis in patients with Clostridium difficile infection

BACKGROUND/AIM

Clostridium difficile infection (CDI) can affect up to 8% of hospitalized patients. Twenty-five percent CDI patients may develop C. difficile associated diarrhea (CDAD) and 1-3% may progress to fulminant C. difficile colitis (FCDC). Once developed, FCDC has higher rates of complications and mortality.

PATIENTS AND METHODS

A 10-year retrospective review of FCDC patients who underwent colectomy was performed and compared with randomly selected age- and sex-matched non-fulminant CDAD patients at our institution. FCDC (n=18) and CDAD (n=49) groups were defined clinically, radiologically, and pathologically. Univariate analysis was performed using Chi-square and Student's t test followed by multivariate logistic regression to compute independent predictors.

RESULTS

FCDC patients were significantly older (77 ± 13 years), presented with triad of abdominal pain (89%), diarrhea (72%), and distention (39%); 28% had prior CDI and had greater hemodynamic instability. In contrast, CDAD patients were comparatively younger (65 ± 20 years), presented with only 1 or 2 of these 3 symptoms and only 5% had prior CDI. No significant difference was noted between the 2 groups in terms of comorbid conditions, use of antibiotics, or proton pump inhibitor. Leukocytosis was significantly higher in FCDC patients (18.6 ± 15.8/mm³ vs 10.7 ± 5.2/mm³; P=0.04) and further increased until the point of surgery. Use of antiperistaltic medications was higher in FCDC than CDAD group (56% vs 22%; P=0.01).

CONCLUSIONS

Our data suggest several clinical and laboratory features in CDI patients, which may be indicative of FCDC. These include old age (>70 years), prior CDI, clinical triad of increasing abdominal pain, distention and diarrhea, profound leukocytosis (>18,000/mm³), hemodynamic instability, and use of antiperistaltic medications.

The morbidity of Clostridium difficile infection after elective colonic resection-results from a national population database

BACKGROUND

Clostridium difficile (CD), a gram-positive rod bacterium, resides normally within the human colon. Antibiotic treatment alters normal colonic flora, potentiating abnormal overgrowth of CD.

METHODS

This study examined the 2004 to 2006 Nationwide Inpatient Sample to determine outcomes of CD colitis after 695,010 elective colonic resections.

RESULTS

CD infection, occurring in 1.4% of patients, was associated with higher pulmonary (12.1% vs 6.4%) and gastrointestinal (12.8% vs 10.5%) complications as well as an increased length of stay (22.6 vs 10.9 days) and mortality (16.2% vs 4.9%; all P < .001). CD colitis patients more frequently held Medicare insurance (68% vs 51%) and underwent small segmental colonic resection as opposed to a defined anatomic resection (20.0% vs 9.9%; P < .001). An underlying diagnosis of colon cancer was associated with a lower incidence of CD colitis (odds ratio, .71; 95% confidence interval, .59-.84; P < .001).

CONCLUSIONS

CD colitis is associated with worse outcomes after elective colonic resection.