Clinical recognition and diagnosis of Clostridium difficile infection

Laboratory comparison between cell cytotoxicity neutralization assay and ultrasensitive single molecule counting technology for detection of Clostridioides difficile toxins A and B, PCR, enzyme immunoassays, and multistep algorithms

Diagnostic tests for Clostridioides difficile infection (CDI) lack either specificity (nucleic acid amplification tests) or sensitivity (enzyme immunoassays; EIAs). The performance of the Singulex Clarity® C. diff toxins A/B assay was compared to cell cytotoxicity neutralization assay. Testing was also performed using an EIA for glutamate dehydrogenase (GDH) and C. difficile toxins A and B (C. Diff Quik Chek Complete®), polymerase chain reaction (PCR) (BD MAX™ Cdiff Assay), and 2 multistep algorithms: algorithm 1 (discordant GDH/toxin results arbitrated by PCR) and algorithm 2 (PCR-positive samples tested with toxin EIA). The Clarity assay and PCR both had 97% sensitivity, while specificity was 100% for Clarity and 79% for PCR. Algorithm 1 yielded 41% discordant results, and both toxin EIA and algorithm 2 had 58% sensitivity. Median toxin concentrations, as measured by the Clarity C. difficile toxin assay, were 3590, 11.5, 0.4, and 0 pg/mL for GDH+/toxin+, GDH+/toxin-/PCR+, GDH+/toxin-/PCR-, and GDH-/toxin- samples, respectively (P < 0.001). The Clarity assay may offer a single-test solution for CDI.

Risk factors and outcomes of Clostridium difficile infection in hospitalized patients

BACKGROUND

The aim of this study was to identify risk factors for Clostridium difficile infection (CDI) and its attributable mortality and to propose methods to prevent CDI and improve patients' outcomes.

METHODS

CDI was defined as diarrheal patients with stool samples that were positive for C. difficile toxin. Clinical presentations of all patients with CDI and two times as many age- and sex-matched culture-negative controls at the Chang Gung Memorial Hospital in 2014 were identified and compared by multivariate, nonparametric, and Kaplan-Meier survival analysis.

RESULTS

There were no significant differences in ages, sex, or Charlson comorbidity indexes between the CDI group (n = 42) and the control group (n = 86). The multivariate analysis indicated that underlying peptic ulcer disease and previous use of gastric acid inhibitors or third-generation cephalosporins for at least 3 days were significantly more common in patients with CDI than in the controls. Charlson scores were associated with mortality due to CDI. Recommended treatment using oral vancomycin to treat patients with Charlson score ≥ 5 and oral metronidazole or vancomycin to treat those with moderate underlying disease (Charlson score ≥ 2 and ≤ 5) significantly increased survival in these patients (p = 0.001).

CONCLUSIONS

Oral vancomycin given to patients with high Charlson scores and oral metronidazole or vancomycin to patients with moderate Charlson scores decreased mortality due to CDI. Restricting the use of third-generation cephalosporins and gastric acid inhibitors is recommended to prevent CDI in hospitalized patients.

Rapid, label-free genetic detection of enteropathogens in stool without genetic isolation or amplification

Current genetic detection methods require gene isolation, gene amplification and detection with a fluorescent-tagged probe. They typically require sophisticated equipment and expensive fluorescent probes, rendering them not widely available for rapid acute infection diagnoses at the point of care to ensure timely treatment of the diseases. Here we report a rapid genetic detection method that can detect the bacterial gene directly from patient stools using a piezoelectric plate sensor (PEPS) in conjunction with a continuous flow system with two temperature zones. With stools spiked with sodium dodecyl sulfate (SDS) in situ bacteria lysing and DNA denaturation occurred in the high-temperature zone whereas in situ specific detection of the denatured DNA by the PEPS occurred in the lower-temperature zone. The outcome was a rapid genetic detection method that directly detected bacterial genes from stool in < 40 min without the need of gene isolation, gene amplification, or expensive fluorescent tag but with polymerase chain reaction (PCR) sensitivity. In 40 blinded patient stools, it detected the toxin B gene of Clostridium difficile with 95% sensitivity and 95% specificity. The all-electrical, label-free nature of the detection further supports its potential as a low-cost genetic test that can be used at the point of care.

Quality of life and utility decrement associated with Clostridium difficile infection in a French hospital setting

Background

Clostridium difficile infection (CDI) is associated with a substantial Quality of life impact on patients that has not been so far measured with a generic validated instrument.

Methods

A prospective study was performed in 7 French acute-care settings in patients presenting with a bacteriologically-confirmed CDI. The EQ-5D-3 L was filled in by patients at 7 ± 2 days after CDI diagnosis to describe their state of health at that date as well as their state of health immediately before the CDI episode (baseline). Individual utility decrement was obtained by subtracting the corresponding utilities. The Quality Adjusted Life Year (QALY) loss was calculated by multiplying the days spent from baseline to the date of the interview, by the decrement of utility. A multivariate analysis of variance of the utility decrement according to CDI and patients characteristics was performed.

Results

Eighty patients were enrolled (mean age: 69.4 years, 55% females). The utility scores dropped from a mean 0.542 (SD: 0.391) at baseline to 0.050 (SD: 0.404) during the CDI episode with a mean adjusted utility decrement of 0.492 (SD: 0.398) point. This decrement increased significantly with CDI severity (Zar score ≥ 3) (p = 0.001), in patients with a positive baseline utility (p = 0.032), in women as compared to men (p = 0.041) and in patients aged more than 65 years (p = 0.041). No association with the Charlson index was found. The associated QALY loss not integrating the excess mortality was 0.028 (SD: 0.053).

Conclusions

The impact on quality of life of CDI episodes is major and translates in a substantial QALY loss despite their short duration.

Electronic supplementary material

The online version of this article (10.1186/s12955-019-1081-5) contains supplementary material, which is available to authorized users.

Recurrent Clostridium difficile infection is associated with treatment failure and prolonged illness in cancer patients

BACKGROUND

Cancer patients are susceptible to recurrent Clostridium difficile infection (CDI) that is increasing globally, necessitating new approaches to prevent fatal consequences. We examined the clinical characteristics of cancer patients with recurrent CDI (RCDI).

PATIENTS AND METHODS

A retrospective review of cancer patients with C. difficile-positive test between January 2015 and May 2017 was carried out. CDI was defined as diarrhea and toxigenic C. difficile detection in the stool by nucleic acid amplification test and enzyme immunoassay. Patients having two CDI episodes were categorized as single recurrent CDI (SRCDI), and those having three or more CDI episodes were categorized as multiple recurrent CDI (MRCDI). Treatment failure was defined as the requirement of antimicrobial alteration or repetition.

RESULTS

We included 170 patients having 270 CDI episodes; 85 patients had non-RCDI, and 85 had RCDI; 14 of them had MRCDI. Previous hospitalization and immunosuppressant use were more frequent in MRCDI group than in SRCDI group (P=0.009 and 0.002, respectively). Physicians treated more SRCDI episodes than MRCDI episodes with metronidazole alone (P=0.017), whereas, more MRCDI episodes needed combination antimicrobials (P=0.072). The mean duration of CDI treatment was longer in the MRCDI group than in the SRCDI group (P=0.030). MRCDI was associated with treatment failure more than SRCDI (P=0.021). The risk for a recurrent episode of CDI was increased in patients who had the following features of the first CDI episode: previous use of antibiotic, NSAID, immunosuppressant, chemotherapy, comorbidities, CDI treatment failure, and severe CDI (P<0.05).

CONCLUSION

Risk factors for RCDI in cancer patients are similar to those without cancer, with the exception of chemotherapy that is only given to cancer patients. Long CDI treatment and CDI treatment failure are associated with MRCDI.

Iron Regulation in Clostridioides difficile

The response to iron limitation of several bacteria is regulated by the ferric uptake regulator (Fur). The Fur-regulated transcriptional, translational and metabolic networks of the Gram-positive, pathogen Clostridioides difficile were investigated by a combined RNA sequencing, proteomic, metabolomic and electron microscopy approach. At high iron conditions (15 μM) the C. difficile fur mutant displayed a growth deficiency compared to wild type C. difficile cells. Several iron and siderophore transporter genes were induced by Fur during low iron (0.2 μM) conditions. The major adaptation to low iron conditions was observed for the central energy metabolism. Most ferredoxin-dependent amino acid fermentations were significantly down regulated (had, etf, acd, grd, trx, bdc, hbd). The substrates of these pathways phenylalanine, leucine, glycine and some intermediates (phenylpyruvate, 2-oxo-isocaproate, 3-hydroxy-butyryl-CoA, crotonyl-CoA) accumulated, while end products like isocaproate and butyrate were found reduced. Flavodoxin (fldX) formation and riboflavin biosynthesis (rib) were enhanced, most likely to replace the missing ferredoxins. Proline reductase (prd), the corresponding ion pumping RNF complex (rnf) and the reaction product 5-aminovalerate were significantly enhanced. An ATP forming ATPase (atpCDGAHFEB) of the F₀F₁-type was induced while the formation of a ATP-consuming, proton-pumping V-type ATPase (atpDBAFCEKI) was decreased. The [Fe-S] enzyme-dependent pyruvate formate lyase (pfl), formate dehydrogenase (fdh) and hydrogenase (hyd) branch of glucose utilization and glycogen biosynthesis (glg) were significantly reduced, leading to an accumulation of glucose and pyruvate. The formation of [Fe-S] enzyme carbon monoxide dehydrogenase (coo) was inhibited. The fur mutant showed an increased sensitivity to vancomycin and polymyxin B. An intensive remodeling of the cell wall was observed, Polyamine biosynthesis (spe) was induced leading to an accumulation of spermine, spermidine, and putrescine. The fur mutant lost most of its flagella and motility. Finally, the CRISPR/Cas and a prophage encoding operon were downregulated. Fur binding sites were found upstream of around 20 of the regulated genes. Overall, adaptation to low iron conditions in C. difficile focused on an increase of iron import, a significant replacement of iron requiring metabolic pathways and the restructuring of the cell surface for protection during the complex adaptation phase and was only partly directly regulated by Fur.

Intrinsic Class D β-Lactamases of Clostridium difficile

Clostridium difficile is the causative agent of the deadly C. difficile infection. Resistance of the pathogen to β-lactam antibiotics plays a major role in the development of the disease, but the mechanism of resistance is currently unknown. We discovered that C. difficile encodes class D β-lactamases, i.e., CDDs, which are intrinsic to this species. We studied two CDD enzymes, CDD-1 and CDD-2, and showed that they display broad-spectrum, high catalytic efficiency against various β-lactam antibiotics, including penicillins and expanded-spectrum cephalosporins. We demonstrated that the cdd genes are poorly expressed under the control of their own promoters and contribute only partially to the observed resistance to β-lactams. However, when the cdd1 gene was expressed under the control of efficient promoters in the antibiotic-sensitive Clostridium cochlearium strain, it produced high-level resistance to β-lactams. Taken together, the results determined in this work demonstrate the existence in C. difficile of intrinsic class D β-lactamases which constitute a reservoir of highly potent enzymes capable of conferring broad-spectrum, clinically relevant levels of resistance to β-lactam antibiotics. This discovery is a significant contribution to elucidation of the mechanism(s) of resistance of the clinically important pathogen C. difficile to β-lactam antibiotics.IMPORTANCEC. difficile is a spore-forming anaerobic bacterium which causes infection of the large intestine with high mortality rates. The C. difficile infection is difficult to prevent and treat, as the pathogen is resistant to many antimicrobial agents. Prolonged use of β-lactam antibiotics for treatment of various infectious diseases triggers the infection, as these drugs suppress the abundance of protective gut bacteria, allowing the resistant C. difficile bacteria to multiply. While resistance of C. difficile to β-lactam antibiotics plays the major role in the development of the disease, the mechanism of resistance is unknown. The significance of our research is in the discovery in C. difficile of β-lactamases, enzymes that destroy β-lactam antibiotics. These findings ultimately can help to combat deadly C. difficile infections.

Evaluation of Risk Factors for Clostridium difficile Infection Based on Immunochromatography Testing and Toxigenic Culture Assay

In recent years, the diagnostic method of choice for Clostridium difficile infection (CDI) is a rapid enzyme immunoassay in which glutamate dehydrogenase (GDH) antigen and C. difficile toxin can be detected (C. diff Quik Chek Complete; Alere Inc.) (Quik Chek). However, the clinical significance remains unclear in cases that demonstrate a positive result for GDH antigen and are negative for toxin. In this study, we used the Quik Chek test kit on fecal samples, with an additional toxin detection step using a toxigenic culture assay for the aforementioned cases. CDI risk factors were assessed among the 3 groups divided by the Quik Chek test results. The study involved 1,565 fecal samples from patients suspected to have CDI who were hospitalized during the period of April 2012 to March 2014. The 3 groups were defined as follows: both GDH antigen positive and toxin positive (by Quik Chek test) (toxin-positive [TP] group, n = 109), both GDH antigen and toxin negative (toxin-negative [TN] group, n = 111), and positive only for GDH antigen but toxin positive with subsequent toxigenic culture (toxigenic culture [TC] group, n = 72). The gender, age, number of hospitalization days, white blood cell (WBC) counts, serum albumin levels, body mass index (BMI), fecal consistency, and use of antibacterials and proton pump inhibiters (PPIs) were analyzed. The positive rate for the fecal direct Quik Chek test was 7.0% (109/1,565 cases). However, toxigenic culture assays using the Quik Chek test for only the GDH-antigen-positive/toxin-negative samples were 35.3% positive (72/204 cases). As a result, the true positive rate for C. difficile toxin detection was estimated to be 11.6% (181/1,565 cases). Moreover, significant differences (P < 0.05) in the number of hospitalization days (>50 days), WBC counts (>10,000 WBCs/μl), and use of PPIs comparing the TN, TP, and TC groups, were observed. The odds ratios (ORs) for the development of CDI were 1.61 (95% confidence interval [CI], 0.94 to 2.74) and 2.98 (95% CI, 1.59 to 5.58) for numbers of hospitalization days, 2.16 (95% CI, 1.24 to 3.75) and 2.24 (95% CI, 1.21 to 4.14) for WBC counts, and 9.03 (95% CI, 4.9 to 16.6) and 9.15 (95% CI, 4.59 to 18.2) for use of PPIs in the TP and TC groups, respectively. These findings demonstrated that the use of PPIs was a significant risk factor for CDI development. Moreover, antibacterials such as carbapenems, cephalosporins, and fluoroquinolones were demonstrated to be risk factors. In conclusion, identification of the TC group of patients is thought to be important, as this study demonstrates that this group bears the same high risk of developing CDI as the TP group.

Prevalence of Clostridium Difficile-Associated Diarrhoea in Hospitalised Patients (Results of a Russian Prospective Multicentre Study)

Introduction

The objective of the study was to evaluate the prevalence of Clostridium difficile-associated diarrhoea (CDAD) among hospitalised patients with antibiotic-associated diarrhoea (AAD) in general and by specific types of medical care and hospital units.

Methods

A prospective, cross-sectional, non-interventional, multicentre study. The main inclusion criteria were: patient age ≥ 18 years, hospital stay of at least 48 h, current antibiotic therapy or antibiotic therapy within the previous 30 days, loose stools (Bristol stool types 5–7 and stool frequency ≥ 3 within ≤ 24 consecutive hours or exceeding normal for the patient) and signed informed consent form. The stool sample was taken to the local (study site) microbiology laboratory for detection of glutamate dehydrogenase (GDH) and toxins A/B using enzyme immunoassay (EIA) stool test.

Results

From April 2016 to April 2017, a total of 1245 patients from 12 large hospitals were enrolled in the study. Data on 81 patients were excluded from the analysis for different reasons. Data on 1164 patients (45.2% males and 54.8% females) with a mean age of 54.9 years (range 18–95 years) were analysed. Length of hospitalisation was 2–188 days (median, 8 days). The EIA stool test showed CDAD-positive results in 21.7% (253/1164) patients. The patients were from surgery units (546/1164), internal medicine units (510/1164) and intensive care units (108/1164). The prevalence of CDAD among patients from surgery, internal medicine and intensive care units was 26.2, 17.8 and 17.6%, respectively. Oncology, gastroenterology, septic surgery, oncohaematology and general medical hospital units accounted for more than 75% of all patients included; the prevalence of CDAD by those hospital units was 11.3, 15.0, 39.2, 17.6, and 27.2%, respectively. The proportion of GDH-positive and toxin A/B-negative patients by the rapid stool test result was 16.8% (196/1164). The prevalence of CDAD varied widely between the hospitals (from 0 to 44.3%).

Conclusions

The prevalence of CDAD among hospitalised patients with AAD in this study was 21.7% (95% confidence interval: 14.8 and 28.7%). The percentage of CDAD varied widely between hospitals and by specific types of medical care and hospital units.

Clostridium difficile Infection in Children

Clostridium difficile is an important cause of health care associated infections. The epidemiology of C. difficile infection (CDI) in children has changed over the past few decades. There is now a higher incidence in hospitalized children, and there has been an emergence of community-onset infection. A hypervirulent strain, North American pulse type 1, has also developed. Neonates and young infants have high rates of colonization but rarely have symptoms. The well-known risk factor for CDI in children age 2 years or older is antibiotic use. Inflammatory bowel disease and cancer are associated with increased incidence and severity of CDI. Nucleic acid amplification tests are now widely used for diagnosis given their rapid turnover and higher sensitivity and specificity. The treatment for an initial episode and first recurrence is oral metronidazole. Oral vancomycin is reserved for second recurrence or severe cases. A new treatment option, fecal bowel transplant, has been reported to be safe and effective in adults, and studies are now being conducted in children. [Pediatr Ann. 2018;47(9):e359-e365.].

A sustained systemic inflammatory response syndrome is associated with shunt-dependent hydrocephalus after aneurysmal subarachnoid hemorrhage

OBJECTIVE

The authors sought to evaluate whether a sustained systemic inflammatory response was associated with shunt-dependent hydrocephalus following aneurysmal subarachnoid hemorrhage.

METHODS

A retrospective analysis of 193 consecutive patients with aneurysmal subarachnoid hemorrhage was performed. Management of hydrocephalus followed a stepwise algorithm to determine the need for external CSF drainage and subsequent shunt placement. Systemic inflammatory response syndrome (SIRS) data were collected for all patients during the first 7 days of hospitalization. Patients who met the SIRS criteria every day for the first 7 days of hospitalization were considered as having a sustained SIRS. Univariate and multivariate regression analyses were used to determine predictors of shunt dependence.

RESULTS

Sixteen percent of patients required shunt placement. Sustained SIRS was observed in 35% of shunt-dependent patients compared to 14% in non-shunt-dependent patients (p = 0.004). On multivariate logistic regression, female sex (OR 0.35, 95% CI 0.142-0.885), moderate to severe vasospasm (OR 3.78, 95% CI 1.333-10.745), acute hydrocephalus (OR 21.39, 95% CI 2.260-202.417), and sustained SIRS (OR 2.94, 95% CI 1.125-7.689) were significantly associated with shunt dependence after aneurysmal subarachnoid hemorrhage. Receiver operating characteristic analysis revealed an area under the curve of 0.83 for the final regression model.

CONCLUSIONS

Sustained SIRS was a predictor of shunt-dependent hydrocephalus following aneurysmal subarachnoid hemorrhage even after adjustment for potential confounding variables in a multivariate logistic regression model.

Toxigenic Clostridium difficile isolates from clinically significant diarrhoea in patients from a tertiary care centre

Background & objectives:

Clostridium difficile is the primary cause of hospital-acquired colitis in patients receiving antibiotics. The pathogenicity of the organism is mainly due to the production of toxins. This study was conducted to investigate the presence of toxigenic C. difficile in the faecal samples of hospitalized patients suspected to have C. difficile infection (CDI) and corroborating the findings with their clinical and demographic data.

Methods:

Diarrhoeic samples obtained from 1110 hospitalized patients were cultured for C. difficile and the isolates confirmed by phenotypic and molecular methods. Toxigenicity of the isolates was determined using enzyme-linked immunosorbent assay for toxins A and B. Details of patients included in the study were noted and analyzed.

Results:

Of the 1110 patients (mean age 39±19.6 yr), 63.9 per cent were males and 36.1 per cent were females. The major antibiotics received by the patients were nitazoxanide (23.9%), penicillins/penicillin combinations (19.0%), quinolones including fluoroquinolones (13.1%), carbapenems (11.5%), glycopeptides (11.0%) and cephalosporins (8.4%). The clinical symptoms predominantly present were watery diarrhoea (56.4%), fever (40.0%) and abdominal pain (35.3%). The underlying diseases were gastrointestinal disorders (52.6%), followed by cancers (13.2%), surgical conditions (8.3%), and hepatic disorders (8.0%). Of the 174 C. difficile isolates, 54.6 per cent were toxigenic. Toxigenic C. difficile was present in all patients with surgical conditions, 65.2 per cent with cancers and 57.1 per cent with gastrointestinal disorders.

Interpretation & conclusions:

C. difficile was found to be an important cause of gastrointestinal infections in hospitalized patients with underlying diseases and on antibiotics. Clinical conditions of the patients correlating with toxigenic culture can be an important tool for establishing CDI diagnosis.

Antibiotic susceptibility and resistance profiles of Romanian Clostridioides difficile isolates

This study investigated the antibiotic susceptibility patterns and genetic resistance markers of 35 C. difficile strains isolated from patients with C. difficile infection. Vancomycin, metronidazole, tigecycline, teicoplanin, rifampicin, moxifloxacin, cefotaxime, tetracycline, erythromycin, clindamycin, chloramphenicol, linezolid and imipenem MICs were determined for toxigenic strains belonging to PCR ribotypes (PR) 012 (2), 014 (4), 017 (3), 018 (2), 027 (17), 046 (2), 087 (3) and 115 (2). Results showed vancomycin, metronidazole, tigecycline and teicoplanin to be active against all isolates. High resistance rates were noticed against cefotaxime (n = 35), clindamycin (n = 33), imipenem (n = 31), moxifloxacin (n = 25), erythromycin (n = 25) and rifampicin (n = 22). Linezolid-resistance was found in three isolates (PR 017/2, PR 012/1), showing complex resistance (7-9 antibiotics). PR 012, 017, 018, 027 and 046 isolates (n = 26) were resistant to 5-9 antibiotics. Twelve resistance profiles (2-9 antibiotics) were detected. Rifampicin-moxifloxacin-cefotaxime-erythromycin-clindamycin-imipenem-resistance was predominant, being expressed by 18 strains (PR 027/17, PR 018/1). PCR results suggested tetracycline-resistance to be induced by the gene tetM. Three tetM-positive isolates (PRs 012, 046), were also tndX-positive, suggesting the presence of a Tn5397-like element. Only two MLSB-resistant strains (PR 012) had the ermB gene and chloramphenicol-resistance determinant catD was not detected, leaving room for further investigating resistance mechanisms. Multidrug resistance could be attributed to most analysed strains, underlining, once more, the impact of wide-spectrum antimicrobial over prescription, still a tendency in our country, on transmission of antimicrobial resistance and emergence of epidemic C. difficile strains generating outbreaks.

Is Clostridium difficile infection a real threat in patients with ulcerative colitis? A prospective, multicenter study in Korea

Background/Aims

Clostridium difficile infection (CDI) has been reported to be a cause of flare-ups in patients with ulcerative colitis (UC). We evaluated the prevalence and clinical outcomes of CDI in patients with UC hospitalized for flare-ups.

Methods

This was a prospective, multicenter study including 7 academic teaching hospitals in Korea. All consecutive patients with UC admitted for disease flare-up were enrolled. We detected the presence of CDI by using enzyme immunoassay, real-time polymerase chain reaction (RT-PCR) for toxin genes, and sigmoidoscopy.

Results

Eighty-one consecutive patients with UC were enrolled from January 2014 to December 2015. Among 81 patients, 8 (9.9%) were diagnosed with CDI. Most of the cases were identified by RT-PCR. Enzyme immunoassay was positive in 3 of 8 patients, and only 1 had typical endoscopic findings of pseudomembranous colitis. There were no differences in demographic data, length of hospital stay, or colectomy rate between patients with and without CDI.

Conclusions

CDI was not a rare cause of flare-up in patients with UC in Korea. However, CDI did not appear to affect the course of UC flare-up in Korean patients. RT-PCR was sensitive in detecting CDI and can be considered a diagnostic tool in patients with UC flare-up.

Microbial Preparations (Probiotics) for the Prevention of Clostridium difficile Infection in Adults and Children: An Individual Patient Data Meta-analysis of 6,851 Participants

OBJECTIVETo determine whether probiotic prophylaxes reduce the odds of Clostridium difficile infection (CDI) in adults and children.DESIGNIndividual participant data (IPD) meta-analysis of randomized controlled trials (RCTs), adjusting for risk factors.METHODSWe searched 6 databases and 11 grey literature sources from inception to April 2016. We identified 32 RCTs (n=8,713); among them, 18 RCTs provided IPD (n=6,851 participants) comparing probiotic prophylaxis to placebo or no treatment (standard care). One reviewer prepared the IPD, and 2 reviewers extracted data, rated study quality, and graded evidence quality.RESULTSProbiotics reduced CDI odds in the unadjusted model (n=6,645; odds ratio [OR] 0.37; 95% confidence interval [CI], 0.25-0.55) and the adjusted model (n=5,074; OR, 0.35; 95% CI, 0.23-0.55). Using 2 or more antibiotics increased the odds of CDI (OR, 2.20; 95% CI, 1.11-4.37), whereas age, sex, hospitalization status, and high-risk antibiotic exposure did not. Adjusted subgroup analyses suggested that, compared to no probiotics, multispecies probiotics were more beneficial than single-species probiotics, as was using probiotics in clinical settings where the CDI risk is ≥5%. Of 18 studies, 14 reported adverse events. In 11 of these 14 studies, the adverse events were retained in the adjusted model. Odds for serious adverse events were similar for both groups in the unadjusted analyses (n=4,990; OR, 1.06; 95% CI, 0.89-1.26) and adjusted analyses (n=4,718; OR, 1.06; 95% CI, 0.89-1.28). Missing outcome data for CDI ranged from 0% to 25.8%. Our analyses were robust to a sensitivity analysis for missingness.CONCLUSIONSModerate quality (ie, certainty) evidence suggests that probiotic prophylaxis may be a useful and safe CDI prevention strategy, particularly among participants taking 2 or more antibiotics and in hospital settings where the risk of CDI is ≥5%.TRIAL REGISTRATIONPROSPERO 2015 identifier: CRD42015015701Infect Control Hosp Epidemiol 2018;771-781.

Novel Antimicrobials for the Treatment of Clostridium difficile Infection

The current picture of Clostridium difficile infection (CDI) is alarming with a mortality rate ranging between 3% and 15% and a CDI recurrence rate ranging from 12% to 40%. Despite the great efforts made over the past 10 years to face the CDI burden, there are still gray areas in our knowledge on CDI management. The traditional anti-CDI antimicrobials are not always adequate in addressing the current needs in CDI management. The aim of our review is to give an update on novel antimicrobials for the treatment of CDI, considering the currently available evidences on their efficacy, safety, molecular mechanism of action, and their probability to be successfully introduced into the clinical practice in the near future. We identified, through a PubMed search, 16 novel antimicrobial molecules under study for CDI treatment: cadazolid, surotomycin, ridinilazole, LFF571, ramoplanin, CRS3123, fusidic acid, nitazoxanide, rifampin, rifaximin, tigecycline, auranofin, NVB302, thuricin CD, lacticin 3147, and acyldepsipeptide antimicrobials. In comparison with the traditional anti-CDI antimicrobial treatment, some of the novel antimicrobials reviewed in this study offer several advantages, i.e., the favorable pharmacokinetic and pharmacodynamic profile, the narrow-spectrum activity against CD that implicates a low impact on the gut microbiota composition, the inhibitory activity on CD sporulation and toxins production. Among these novel antimicrobials, the most active compounds in reducing spore production are cadazolid, ridinilazole, CRS3123, ramoplanin and, potentially, the acyldepsipeptide antimicrobials. These antimicrobials may potentially reduce CD environment spread and persistence, thus reducing CDI healthcare-associated acquisition. However, some of them, i.e., surotomycin, fusidic acid, etc., will not be available due to lack of superiority versus standard of treatment. The most CD narrow-spectrum novel antimicrobials that allow to preserve microbiota integrity are cadazolid, ridinilazole, auranofin, and thuricin CD. In conclusion, the novel antimicrobial molecules under development for CDI have promising key features and advancements in comparison to the traditional anti-CDI antimicrobials. In the near future, some of these new molecules might be effective alternatives to fight CDI.

Applications of CRISPR/Cas System to Bacterial Metabolic Engineering

The clustered regularly interspaced short palindromic repeats/CRISPR-associated (CRISPR/Cas) adaptive immune system has been extensively used for gene editing, including gene deletion, insertion, and replacement in bacterial and eukaryotic cells owing to its simple, rapid, and efficient activities in unprecedented resolution. Furthermore, the CRISPR interference (CRISPRi) system including deactivated Cas9 (dCas9) with inactivated endonuclease activity has been further investigated for regulation of the target gene transiently or constitutively, avoiding cell death by disruption of genome. This review discusses the applications of CRISPR/Cas for genome editing in various bacterial systems and their applications. In particular, CRISPR technology has been used for the production of metabolites of high industrial significance, including biochemical, biofuel, and pharmaceutical products/precursors in bacteria. Here, we focus on methods to increase the productivity and yield/titer scan by controlling metabolic flux through individual or combinatorial use of CRISPR/Cas and CRISPRi systems with introduction of synthetic pathway in industrially common bacteria including Escherichia coli. Further, we discuss additional useful applications of the CRISPR/Cas system, including its use in functional genomics.

Reducing Clostridium difficile Colitis Rates Via Cost-Saving Diagnostic Stewardship

We conducted a quality improvement project at a large public tertiary-care academic hospital to reduce reported hospital-acquired Clostridium difficile infection (CDI) rates. We introduced diagnostic stewardship and provider education, resulting in a 2-fold reduction in C. difficile nucleic acid amplification test (NAAT) orders and markedly lower hospital CDI rate.

Infect Control Hosp Epidemiol 2018;39:734–736

Foal Diarrhea: Established and Postulated Causes, Prevention, Diagnostics, and Treatments

Diarrhea is one of the most important diseases in young foals and may occur in more than half of foals until weaning age. Several infectious and noninfectious underlying causes have been implicated but scientific evidence of pathogenesis is evolving. It is important to investigate all known potential causes and identify infectious agents to avoid outbreaks, evaluate the level of systemic compromise, and establish adequate therapy. It is crucial to differentiate foals that can be managed in field conditions from those that should be sent to a referral center. This article reviews these aspects and recent developments in the diagnostic and therapeutic approaches.

Prophylactic Antibiotics for Elective Laparoscopic Cholecystectomy

Surgical site infections with elective laparoscopic cholecystectomy are less frequent and less severe, leading some to suggest that prophylactic antibiotics (PA) are no longer indicated. We compared the incidence of surgical site infections before and after an institutional practice change of withholding PA for elective laparoscopic cholecystectomy. Between May 7, 2013, and March 11, 2015, no PA were given to patients selected for elective cholecystectomy by two surgeons at a single center. The only patients excluded were those who received antibiotics before surgery for any reason. All others, including those at high risk for infection, were included. The incidence and severity of infections were compared with historical controls treated with prophylaxis by the same two surgeons from November 6, 2011, to January 13, 2013. There were 268 patients in the study group and 119 patients in the control group. Infection occurred in 3.0 per cent in the study group compared with 0.9 per cent in the controls ( P = 0.29). All infections were mild except one. Based on these data, the routine use of PA for elective laparoscopic cholecystectomy is not supported.

Impact of simultaneous glutamate dehydrogenase and toxin A/B rapid immunoassay on Clostridium difficile diagnosis and treatment in hospitalized patients with antibiotic-associated diarrhea in a university hospital of Brazil

BACKGROUND AND AIM

Clostridium difficile is a major cause of health care-associated infection, but disagreement between diagnostic tests is an ongoing barrier to clinical decision-making. Conventional enzyme immunoassay (EIA) for toxin detection is currently the most frequently used technique for C. difficile infection (CDI) diagnosis, but its low sensitivity makes the development of an alternative strategy necessary for improving the diagnosis in developing countries.

METHODS

Between years 2011 and 2015, 154 stool samples from patients with antibiotic-associated diarrhea were examined by toxigenic culture and EIA for the diagnosis of CDI. In the year 2015, when glutamate dehydrogenase (GDH) test was first available in Brazil, 53 of those fecal specimens were also tested by the C. diff Quik Chek Complete rapid immunoassay. At this time, we prospectively assessed the impact of this test on CDI treatment rates before and after it was introduced in clinical practice.

RESULTS

The GDH component of C. diff Quik Chek Complete test had a sensitivity of 100% and specificity of 95.1% compared with toxigenic culture, with 89.8% concordance. The Tox A/B II EIA and the toxin portion of C. diff Quik Chek Complete yielded sensitivities between values of 50-58.3%, with 100% specificities. The introduction of GDH test increased the number of treated patients with CDI from 57.7% to 100%.

CONCLUSIONS

Glutamate dehydrogenase test is a reliable method for the diagnosis of CDI and greatly increases the number of properly treated patients with CDI. Therefore, this exam should be considered the mainstay for the laboratory diagnosis of CDI in developing countries.

PCR ribotyping and antimicrobial susceptibility testing of isolates of Clostridium difficile cultured from toxin-positive diarrheal stools of patients receiving medical care in Canadian hospitals: the Canadian Clostridium difficile Surveillance Study (CAN-DIFF) 2013-2015

Clostridium difficile toxin-positive diarrheal stool specimens submitted to eight Canadian hospital laboratories from 2013 to 2015 were cultured. Polymerase chain reaction ribotyping of isolates was performed using an internationally standardized, high-resolution capillary gel-based electrophoresis protocol and antimicrobial susceptibility testing conducted by CLSI-defined agar dilution (M11-A8, 2012). Among the 1310 isolates of C. difficile cultured, 141 different ribotypes were identified; the most common ribotypes were 027 (24.5% of isolates), 014 (7.7%), 020 (6.6%), 106 (6.1%), and 002 (4.6%). Ribotype 027 was the commonest ribotype in all geographic regions of Canada and was more frequently isolated from patients aged ≥80 years (40.6%) than younger patients (P<0.00001). Ribotype 027 isolates were frequently moxifloxacin-resistant (92.2% of isolates) and multidrug-resistant (49.5%). Fidaxomicin demonstrated the greatest in vitro potency (lowest MIC₉₀, 0.5 μg/mL; lowest maximum MIC, 2 μg/mL) of eight antimicrobial agents tested and was the most active agent against each of the five commonest ribotypes (MIC₉₀, 0.25-1 μg/mL).

New Insights into Clostridium difficile (CD) Infection in Latin America: Novel Description of Toxigenic Profiles of Diarrhea-Associated to CD in Bogotá, Colombia

Clostridium difficile (CD) produces antibiotic associated diarrhea and leads to a broad range of diseases. The source of CD infection (CDI) acquisition and toxigenic profile are factors determining the impact of CD. This study aimed at detecting healthcare facility onset- (HCFO) and community-onset (CO) CDI and describing their toxigenic profiles in Bogotá, Colombia. A total of 217 fecal samples from patients suffering diarrhea were simultaneously submitted to two CDI detection strategies: (i) in vitro culture using selective chromogenic medium (SCM; chromID, bioMérieux), followed verification by colony screening (VCS), and (ii) molecular detection targeting constitutive genes, using two conventional PCR tests (conv.PCR) (conv.16S y conv.gdh) and a quantitative test (qPCR.16s). The CD toxigenic profile identified by any molecular test was described using 6 tests independently for describing PaLoc and CdtLoc organization. High overall CDI frequencies were found by both SCM (52.1%) and conv.PCR (45.6% for conv.16S and 42.4% for conv.gdh), compared to reductions of up to half the frequency by VCS (27.2%) or qPCR.16S (22.6%). Infection frequencies were higher for SCM and conv.16S regarding HCFO but greater for CO concerning conv.gdh, such differences being statistically significant. Heterogeneous toxigenic profiles were found, including amplification with lok1/3 primers simultaneously with other PaLoc markers (tcdA, tcdB or tcdC). These findings correspond the first report regarding the differential detection of CDI using in vitro culture and molecular detection tests in Colombia, the circulation of CD having heterogeneous toxigenic profiles and molecular arrays which could affect the impact of CDI epidemiology.

Acid-Suppressive Therapy and Risk of Infections: Pros and Cons

This narrative review summarises the benefits, risks and appropriate use of acid-suppressing drugs (ASDs), proton pump inhibitors and histamine-2 receptor antagonists, advocating a rationale balanced and individualised approach aimed to minimise any serious adverse consequences. It focuses on current controversies on the potential of ASDs to contribute to infections-bacterial, parasitic, fungal, protozoan and viral, particularly in the elderly, comprehensively and critically discusses the growing body of observational literature linking ASD use to a variety of enteric, respiratory, skin and systemic infectious diseases and complications (Clostridium difficile diarrhoea, pneumonia, spontaneous bacterial peritonitis, septicaemia and other). The proposed pathogenic mechanisms of ASD-associated infections (related and unrelated to the inhibition of gastric acid secretion, alterations of the gut microbiome and immunity), and drug-drug interactions are also described. Both probiotics use and correcting vitamin D status may have a significant protective effect decreasing the incidence of ASD-associated infections, especially in the elderly. Despite the limitations of the existing data, the importance of individualised therapy and caution in long-term ASD use considering the balance of benefits and potential harms, factors that may predispose to and actions that may prevent/attenuate adverse effects is evident. A six-step practical algorithm for ASD therapy based on the best available evidence is presented.

Early Results of Fecal Microbial Transplantation Protocol Implementation at a Community-based University Hospital

Introduction:

Clostridium difficile (CD) is a serious and increasingly prevalent healthcare-associated infection. The pathogenesis of CD infection (CDI) involves the acquisition of CD with a concurrent disruption of the native gut flora. Antibiotics are a major risk although other contributing factors have also been identified. Clinical management combines discontinuation of the offending antibiotic, initiation of CD-specific antibiotic therapy, probiotic agent use, fecal microbiota transplantation (FMT), and surgery as the “last resort” option. The aim of this study is to review short-term clinical results following the implementation of FMT protocol (FMTP) at our community-based university hospital.

Methods:

After obtaining Institutional Review Board and Infection Control Committee approvals, we implemented an institution-wide FMTP for patients diagnosed with CDI. Prospective tracking of all patients receiving FMT between July 1, 2015, and February 1, 2017, was conducted using REDCap™ electronic data capture system. According to the FMTP, indications for FMT included (a) three or more CDI recurrences, (b) two or more hospital admissions with severe CDI, or (c) first episode of complicated CDI (CCDI). Risk factors for initial infection and for treatment failure were assessed. Patients were followed for at least 3 months to monitor for cure/failure, relapse, and side effects. Frozen 250 mL FMT samples were acquired from OpenBiome (Somerville, MA, USA). After 4 h of thawing, the liquid suspension was applied using colonoscopy, beginning with terminal ileum and proceeding distally toward mid-transverse colon. Monitored clinical parameters included disease severity (Hines VA CDI Severity Score or HVCSS), concomitant medications, number of FMT treatments, non-FMT therapies, cure rates, and mortality. Descriptive statistics were utilized to outline the study results.

Results:

A total of 35 patients (mean age 58.5 years, 69% female) were analyzed, with FMT-attributable primary cure achieved in 30/35 (86%) cases. Within this subgroup, 2/30 (6.7%) patients recurred and were subsequently cured with long-term oral vancomycin. Among five primary FMT failures (14% total sample), 3 (60%) achieved medical cure with long-term oral vancomycin therapy and 2 (40%) required colectomy. For the seven patients who either failed FMT or recurred, long-term vancomycin therapy was curative in all but two cases. For patients with severe CDI (HVCSS ≥3), primary and overall cure rates were 6/10 (60%) and 8/10 (80%), respectively. Patients with CCDI (n = 4) had higher HVCSS (4 vs. 3) and a mortality of 25%. Characteristics of patients who failed initial FMT included older age (70 vs. 57 years), female sex (80% vs. 67%), severe CDI (80% vs. 13%), and active opioid use during the initial infection (60% vs. 37%) and at the time of FMT (60% vs. 27%). The most commonly reported side effect of FMT was loose stools.

Conclusions:

This pilot study supports the efficacy and safety of FMT administration for CDI in the setting of a community-based university hospital. Following FMTP implementation, primary (86%) and overall (94%) nonsurgical cure rates were similar to those reported in other studies. The potential role of opioids as a modulator of CDI warrants further clinical investigation.

Diagnosis and management of gastrointestinal complications in adult cancer patients: 2017 updated evidence-based guidelines of the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO)

Cancer patients frequently suffer from gastrointestinal complications. In this manuscript, we update our 2013 guideline on the diagnosis and management of gastrointestinal complications in adult cancer patients by the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO). An expert group was put together by the AGIHO to update the existing guideline. For each sub-topic, a literature search was performed in PubMed, Medline, and Cochrane databases, and strengths of recommendation and the quality of the published evidence for major therapeutic strategies were categorized using the 2015 European Society for Clinical Microbiology and Infectious Diseases (ESCMID) criteria. Final recommendations were approved by the AGIHO plenary conference. Recommendations were made with respect to non-infectious and infectious gastrointestinal complications. Strengths of recommendation and levels of evidence are presented. A multidisciplinary approach to the diagnosis and management of gastrointestinal complications in cancer patients is mandatory. Evidence-based recommendations are provided in this updated guideline.

Ribotypes and New Virulent Strains Across Europe

Clostridium difficile is a major bacterial cause of post-antibiotic diarrhoea. The epidemiology of C. difficile infections (CDI) has dramatically changed since the early 2000s, with an increasing incidence and severity across Europe. This trend is partly due to the emergence and rapid worldwide spread of the hypervirulent and epidemic PCR ribotype 027. Profiles of patients with CDI have also evolved, with description of community-acquired (CA) infections in patients with no traditional risk factors for CDI. However, recent epidemiological studies indicated that some European countries have successfully controlled the dissemination of the 027 clone whereas other countries recently reported the emergence of other virulent or unusual strains. The aims of this review are to summarize the current European CDI epidemiology and to describe the new virulent C. difficile strains circulating in Europe, as well as other potential emerging strains described elsewhere. Standardized typing methods and surveillance programmes are mandatory for a better understanding and monitoring of CDI in Europe.

Diagnostic Guidance for C. difficile Infections

Diagnosis of Clostridium difficile infection (CDI) can be challenging. First of all, there has been debate on which of the two reference assays, cell cytotoxicity neutralization assay (CCNA) or toxigenic culture (TC) should be considered the gold standard for CDI detection. Although the CCNA suffers most from suboptimal storage conditions and subsequent toxin degradation, TC is reported to falsely increase CDI detection rates as it cannot differentiate CDI patients from patients asymptomatically colonised by toxigenic C. difficile. Several rapid assays are available for CDI detection and fall into three broad categories: (1) enzyme immunoassays for glutamate dehydrogenase, (2) enzyme immunoassays for toxins A/B and (3) nucleic acid amplification tests detecting toxin genes. All three categories have their own limitations, being suboptimal specificity and/or sensitivity or the inability to discern colonised patients from CDI patients. In light of these limitations, multi-step algorithmic testing has now been advocated by international guidelines in order to optimize diagnostic accuracy. Despite these recommendations, testing methods between hospitals vary widely, which impacts CDI incidence rates. CDI incidence rates are also influenced by sample selection criteria, as several studies have shown that if not all unformed stool samples are tested for CDI, many cases may be missed due to an absence of clinical suspicion. Since methods for diagnosing CDI remain imperfect, there has been a growing interest in alternative testing strategies like faecal biomarkers, immune modulating interleukins, cytokines and imaging methods. At the moment, these alternative methods might play an adjunctive role, but they are not suitable to replace conventional CDI testing strategies.

Burden and Management of Multidrug-Resistant Organisms in Palliative Care

Palliative care includes comprehensive strategies to optimize quality of life for patients and families confronting terminal illness. Infections are a common complication in terminal illness, and infections due to multidrug-resistant organisms (MDROs) are particularly challenging to manage in palliative care. Limited data suggest that palliative care patients often harbor MDRO. When MDROs are present, distinguishing colonization from infection is challenging due to cognitive impairment or metastatic disease limiting symptom assessment and the lack of common signs of infection. Multidrug-resistant organisms also add psychological burden through infection prevention measures including patient isolation and contact precautions which conflict with the goals of palliation. Moreover, if antimicrobial therapy is indicated per goals of care discussions, available treatment options are often limited, invasive, expensive, or associated with adverse effects that burden patients and families. These issues raise important ethical considerations for managing and containing MDROs in the palliative care setting.

Comparative genomic analysis of Clostridium difficile ribotype 027 strains including the newly sequenced strain NCKUH-21 isolated from a patient in Taiwan

Background

Clostridium difficile is a Gram-positive anaerobe and the leading cause of antibiotic-associated diarrhea worldwide. The emergence of ribotype 027 (RT027) strains is associated with increased incidence of infection and mortality. To further understand the relationship between C. difficile NCKUH-21, a RT027 strain isolated from a patient in Taiwan, and other RT027 strains, we performed whole-genome shotgun sequencing on NCKUH-21 and comparative genomic analyses.

Results

The genome size, G+C content, and gene number for the NCKUH-21 strain were determined to be similar to those for other C. difficile strains. The core genome phylogeny indicated that the five RT027 strains R20291, CD196, NCKUH-21, BI1, and 2007855 formed a clade. A pathogenicity locus, tcdR-tcdB-tcdE-orf-tcdA-tcdC, was conserved in the genome. A genomic region highly similar to the Clostridium phage \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\upvarphi$$\end{document}φCD38-2 was present in the NCKUH-21 strain but absent in the other RT027 strains and designated as the prophage \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\upvarphi$$\end{document}φNCKUH-21. The prophage \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\upvarphi$$\end{document}φNCKUH-21 genes were significantly higher in G+C content than the other genes in the NCKUH-21 genome, indicating that the prophage does not match the base composition of the host genome.

Conclusions

This is the first whole-genome analysis of a RT027 C. difficile strain isolated from Taiwan. Due to the high identity with \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\upvarphi$$\end{document}φCD38-2, the prophage identified in the NCKUH-21 genome has the potential to regulate toxin production. These results provide important information for understanding the pathogenicity of RT027 C. difficile in Taiwan.

Electronic supplementary material

The online version of this article (10.1186/s13099-017-0219-4) contains supplementary material, which is available to authorized users.

Management of candidemia in patients with Clostridium difficile infection

INTRODUCTION

Patients with C. difficile infection (CDI) experience intestinal microflora changes that can promote the overgrowth and subsequent translocation of gut resident pathogens into the blood. Consistently, CDI due to PCR-ribotype 027 strain, severe or relapsing CDI, and treatment with high-dosage vancomycin are independent risk factors for candidemia.

AREAS COVERED

We review the role played by the gut microbiota during CDI and its treatment, as well as the clinical profile of CDI patients who are at risk of developing candidemia. Also, we discuss the management of these patients by focusing on pre-emptive strategies aimed at reducing the risk of candidemia, and on innovative anti-C. difficile therapies that may mitigate CDI-related effects such as the altered gut microbiota composition and prolonged intestinal mucosa damage. Expert commentary: A closer clinical and diagnostic monitoring of patients with CDI should help to limit the CDI-associated long-term consequences, including Candida infections, which worsen the outcome of hospitalized patients.

Clinical Practice and Infrastructure Review of Fecal Microbiota Transplantation for Clostridium difficile Infection

A substantial proportion of Clostridium difficile infection (CDI) cases recur after completion of antibiotic therapy, and antibiotic cure rates diminish with each recurrence of CDI. Fecal microbiota transplantation (FMT) is an effective therapy for recurrent FMT, which otherwise requires prolonged or indefinite antibiotic treatment. FMT is performed by introducing the fecal microbial community obtained from a healthy donor or pool of donors into the stomach, small intestine, or colon of a patient with CDI. Multiple clinical trials support the usefulness of FMT in treating recurrent CDI, and CDI treatment guidelines now include consideration of FMT at the third CDI recurrence. However, there remain challenges to incorporating FMT into clinical practice. First, methods of fecal bacterial community processing vary, as do methods of FMT administration. Second, the optimal dosing strategy and expected benefit of FMT for refractory CDI, particularly for severe and severe complicated cases, are uncertain. Third, the US Food and Drug Administration (FDA) considers FMT an investigational treatment. Fourth, insurance reimbursement for FMT usually falls short of FMT administration costs. In the setting of rising C difficile incidence and growing evidence for FMT efficacy, the demand for FMT has increased. However, uncertainty surrounding optimal FMT preparation and administration methods, FDA oversight, and insurance reimbursement presently limits the clinical practice of FMT.

CD2068 potentially mediates multidrug efflux in Clostridium difficile

Clostridium difficile is a major cause of antibiotic-associated diarrhea and the treatment thereof becomes more difficult owing to a rise of multidrug resistant strains. ATP-binding cassette (ABC) transporters are known to play a crucial role in the resistance to multiple antibiotics. In this study, the potential contribution of an ABC transporter in C. difficile multidrug resistance was investigated. The expression level of the cd2068 gene in C. difficile encoding an ABC transporter was up-regulated following the exposure to certain antibiotics compared to the control cells. Heterologous expression of CD2068 in Escherichia coli revealed that it mediated the efflux of fluorescent substrates and conferred resistance to multiple drugs. The CD2068-associated ATPase activity in membrane vesicles was also stimulated by various antibiotics. Furthermore, the insertional inactivation of the cd2068 gene in C. difficile led to a significant increase in susceptibility to antibiotics, which could be genetically complemented, supporting that CD2068 was directly associated to the drug resistance. These results demonstrate the potential role for the ABC transporter CD2068 in the resistance mechanism against multiple drugs in C. difficile.

Evaluation of Copan FecalSwab as Specimen Type for Use in Xpert C. difficile Assay

Liquid-based microbiology (LBM) devices incorporating flocked swabs and preservation medium ease transport of specimens and improve specimen yield compared to traditional fiber wound swabs; however, the performance of LBM collection devices has not been evaluated in many molecular assays. It is unclear how the differences in matrix and specimen loading with an LBM device will affect test performance compared to traditional collection devices. The purpose of this study was to evaluate the performance of specimens collected in FecalSwab transport medium (Copan Diagnostics, Murrieta, CA) compared to unpreserved stool using the Cepheid Xpert C. difficile assay (Cepheid, Sunnyvale, CA). Results equivalent to unpreserved stool samples were obtained when 400 μl of FecalSwab-preserved stool was employed in the Xpert assay. The positive and negative percent agreement of specimens inoculated with FecalSwab medium (n = 281) was 97.0% (95% confidence interval [CI], 90.9 to 96.4%) and 99.4% (95% CI, 96.4 to 99.9%), respectively, compared to reference results obtained using unpreserved stool. Throughout this study, only four discrepant results occurred when comparing preserved specimens to unpreserved stool specimens in the Xpert C. difficile PCR assay. Post discrepant analysis, using the BD MAX Cdiff assay, the specificity and sensitivity both increased to 100%. The high positive and negative percent agreements observed in this study suggest that stool preserved in FecalSwab media yields equivalent results to using unpreserved stool when tested on the Xpert C. difficile assay, allowing laboratories to adopt this liquid-based microbiology collection device.

Clostridium Difficile, Colitis, and Colonoscopy: Pediatric Perspective

PURPOSE OF THE REVIEW

Review tests available for detection of Clostridium difficile (C. Diff) induced disease, including when such tests should be done in children and how they should be interpreted.

RECENT FINDINGS

Multiple tests are available for detecting disease due to C. diff. These include colonoscopy and stool analysis. Colonoscopy with biopsy is the most sensitive test for detecting the presence of colitis. The toxins produced by the C. diff. (toxin A, toxin B, and binary toxin) are the agents that cause injury and disease. Only toxin producing C. diff. Strains will cause disease. Binary toxin by itself is not thought to produce disease. Binary toxin causes disease in humans when present with toxin A and B producing bacteria, and has been implicated with fulminant life threatening disease. Stool analyses vary in sensitivity and specificity depending on the assay used. The presence of toxin producing strains of C diff. in the stool does not equate with disease. The presence of a toxin-producing bacteria or toxins (A or B) only equates with disease if diarrhea or a diseased colon (toxic megacolon, ileus, and sepsis) is present. Nucleic acid amplification testing (NAAT), when used in the stool from patients with diarrhea, appears to be the most efficient study to detect the gene that encodes for toxin A and B and thus to diagnose C. diff.-induced disease. Infants have a high carriage rate of C. diff. and are believed not to develop disease from it or its toxins. Infants should not be tested for C. difficile. The NAAT is most specific when done on patients with diarrhea with liquid stools. Testing for C. difficile should only be done on patients with diarrhea. One can assume that a patient who has no diarrhea and is not ill does not have C. diff.-induced disease. Treatment should be limited to patients with diarrhea who test positive for C. diff. toxin (A or B) or toxin-producing bacteria. Direct testing for binary toxin is not commercially available. Binary toxin is only thought to cause disease in humans when C. diff. toxin (A and B)-producing bacteria are present.

Recognition and management of Clostridium difficile in older adults

Clostridium difficile infection (CDI) is increasing in the outpatient setting, and older adults are at a higher risk for contracting CDI and experiencing poor outcomes. NPs may see this infection in the primary care setting. This article focuses on the presentation, treatment, and clinical practice implications for CDI in community-dwelling older adults.

Invasive listeriosis in a patient with several episodes of antibiotic associated colitis presumably due to Clostridium difficile

A 62-year-old man developed a blood stream infection and meningitis due to Listeria monocytogenes, 20 days after an episode of pseudo-membranous colitis. The patient, hospitalized for the first time for transurethral prostatectomy, was readmitted 20 days later with watery diarrhea. Pseudo-membranous colitis was diagnosed and treated successfully, without testing for Clostridium difficile infection (CDI). After 15 more days, the patient developed again diarrhea, fever and confusion. Hospitalized again, blood and cerebrospinal fluid cultures resulted positive for L. monocytogenes. The patient was treated successfully and a diagnosis of recurrent CDI was confirmed following culture and nucleic acid amplification assays both positive for C. difficile. This is the first report of an invasive listeriosis after CDI underlines the importance of taking greater awareness in complicated blood stream infections that may arise after CDI.

The Microbiome and Human Biology

Over the past few years, microbiome research has dramatically reshaped our understanding of human biology. New insights range from an enhanced understanding of how microbes mediate digestion and disease processes (e.g., in inflammatory bowel disease) to surprising associations with Parkinson's disease, autism, and depression. In this review, we describe how new generations of sequencing technology, analytical advances coupled to new software capabilities, and the integration of animal model data have led to these new discoveries. We also discuss the prospects for integrating studies of the microbiome, metabolome, and immune system, with the goal of elucidating mechanisms that govern their interactions. This systems-level understanding will change how we think about ourselves as organisms.

Current knowledge on the laboratory diagnosis of Clostridium difficile infection

Clostridium difficile (C. difficile) is a spore-forming, toxin-producing, gram-positive anaerobic bacterium that is the principal etiologic agent of antibiotic-associated diarrhea. Infection with C. difficile (CDI) is characterized by diarrhea in clinical syndromes that vary from self-limited to mild or severe. Since its initial recognition as the causative agent of pseudomembranous colitis, C. difficile has spread around the world. CDI is one of the most common healthcare-associated infections and a significant cause of morbidity and mortality among older adult hospitalized patients. Due to extensive antibiotic usage, the number of CDIs has increased. Diagnosis of CDI is often difficult and has a substantial impact on the management of patients with the disease, mainly with regards to antibiotic management. The diagnosis of CDI is primarily based on the clinical signs and symptoms and is only confirmed by laboratory testing. Despite the high burden of CDI and the increasing interest in the disease, episodes of CDI are often misdiagnosed. The reasons for misdiagnosis are the lack of clinical suspicion or the use of inappropriate tests. The proper diagnosis of CDI reduces transmission, prevents inadequate or unnecessary treatments, and assures best antibiotic treatment. We review the options for the laboratory diagnosis of CDI within the settings of the most accepted guidelines for CDI diagnosis, treatment, and prevention of CDI.

Clostridium difficile Infection: An Orthopaedic Surgeon's Guide to Epidemiology, Management, and Prevention

Clostridium difficile infection is a growing concern in health care and is a worrisome complication in orthopaedics. The incidence and severity of this infection are increasing, although the incidence following orthopaedic surgery is comparatively lower than that seen in patients in most other surgical specialties. The typical geriatric orthopaedic patient may have many risk factors that increase the likelihood of C difficile infection, including advanced age, residence in a long-term care facility, multiple comorbidities, the use of perioperative antibiotics, and a long length of stay. Many antibiotics used for prophylaxis in orthopaedic procedures have been correlated with an increased incidence of C difficile infection. The indications for C difficile testing may vary, and diagnostic methods differ in sensitivity and specificity. The prevention of this infection is multifaceted and consists of practitioner and patient hand hygiene, antibiotic stewardship, contact precautions, and proper environmental cleaning. The main treatment options are metronidazole for mild cases and vancomycin for moderate to severe disease. Up to 40% of cases may have one or more recurrence. Further research is needed to identify novel therapeutic and prevention strategies for C difficile infection.

Clostridium difficile infection in inflammatory bowel disease: challenges in diagnosis and treatment

The problem of Clostridium difficile infection (CDI) has reached epidemic proportions, particularly in industrialized nations. The pathophysiology, disease course and the potential complications are well appreciated in the general hospitalized patient. However, when CDI occurs in the setting of inflammatory bowel disease (IBD), a number of distinct differences in the diagnosis and clinical management of the infection in this population should be appreciated by gastroenterologists, hospitalists and other care providers. This review highlights the unique aspects of CDI when it occurs in IBD patients with an emphasis on the challenge of distinguishing persistent infection from exacerbation of underlying chronic colitis. An understanding of how CDI may differ in presentation and how management should be altered can prevent serious and life-threatening complications.

Point-Counterpoint: What Is the Optimal Approach for Detection of Clostridium difficile Infection?

INTRODUCTIONIn 2010, we published an initial Point-Counterpoint on the laboratory diagnosis of Clostridium difficile infection (CDI). At that time, nucleic acid amplification tests (NAATs) were just becoming commercially available, and the idea of algorithmic approaches to CDI was being explored. Now, there are numerous NAATs in the marketplace, and based on recent proficiency test surveys, they have become the predominant method used for CDI diagnosis in the United States. At the same time, there is a body of literature that suggests that NAATs lack clinical specificity and thus inflate CDI rates. Hospital administrators are taking note of institutional CDI rates because they are publicly reported. They have become an important metric impacting hospital safety ratings and value-based purchasing; hospitals may have millions of dollars of reimbursement at risk. In this Point-Counterpoint using a frequently asked question approach, Ferric Fang of the University of Washington, who has been a consistent advocate for a NAAT-only approach for CDI diagnosis, will discuss the value of a NAAT-only approach, while Christopher Polage of the University of California Davis and Mark Wilcox of Leeds University, Leeds, United Kingdom, each of whom has recently written important articles on the value of toxin detection in the diagnosis, will discuss the impact of toxin detection in CDI diagnosis.

Clostridium difficile–Associated Diarrhea in the Oncology Patient

Clostridium difficile is the most common cause of nosocomial diarrhea, resulting in significant morbidity and mortality in hospitalized patients. Oncology patients are particularly at risk of this infection secondary to frequent exposure to known risk factors. In a population in which diarrhea is a common adverse effect of chemotherapeutic regimens, diagnosis can be challenging secondary to current limitations in testing to differentiate between colonization and active infection. Although several currently available antimicrobial therapies achieve resolution of symptoms in this population, further research is needed to determine which agent least affects the host intestinal microbiota, especially in times of neutropenia and mucosal barrier injury. The purpose of this article is to review the current literature on the epidemiology, pathogenesis, and management of C difficile–associated diarrhea in the oncology population.