Drivers of Clostridioides difficile hypervirulent ribotype 027 spore germination,vegetative cell growth and toxin production in vitro

ObjectivesClostridioides difficile infection (CDI) is a considerable healthcare and economic burden worldwide. Faecal microbial transplant remains the most effective treatment for CDI, but is not at the present time the recommended standard of care. We hereby investigate which factors derived from a healthy gut microbiome might constitute the colonization resistance barrier (CRB) in the gut, inhibiting CDI.MethodsCRB drivers pH, short chain fatty acid (SCFA), and oxidation–reduction potential (ORP) were investigated in vitro using C. difficile NAP1/BI/027. Readouts for inhibitory mechanisms included germination, growth, toxin production and virulence gene expression. pH ranges (3–7.6), SCFA concentrations (25–200 mM) and ORP (–300 to 200 mV) were manipulated in brain heart infusion broth cultures under anaerobic conditions to assess the inhibitory action of these mechanisms.ResultsA pH < 5.3 completely inhibited C. difficile growth to optical density (OD) 0.019 vs. 1.19 for control pH 7.5. Toxin production was reduced to 25 units vs. 3125 units for pH 7.6 (1 in 5 dilutions). Virulence gene expression reduced by 150-fold compared with pH 7.6 (p < 0.05). Germination and proliferation of spores below pH 6.13 yielded an average OD of 0.006 vs. 0.99 for control. SCFA were potent regulators of toxin production at 25 mM and above (p < 0.05). Acetate significantly inhibited toxin production to 25 units independent of OD (0.8733) vs. control (OD 0.6 and toxin titre 3125) (p < 0.05). ORP did not impact C. difficile growth.ConclusionsThis study highlights the critical role that pH has in the CRB, regulating CDI in vitro and that SCFA can regulate C. difficile function independent of pH.     

Clostridioides difficile infection in patients with hematological malignancy: A multicenter study in Taiwan

BackgroundAmong the individuals with hematological malignancy (HM) complicated with Clostridioides difficile infection (CDI), the variables associated with in-hospital mortality and recurrence of CDI were investigated.Material and methodsIncluding adults with HM and those without malignancy suffering from CDI from January 2015 to December 2016 in three hospitals in Taiwan.ResultsTotally 314 patients including 77 with HM and 237 patients without malignancy were included. HM patients more often had low leukocyte counts (<500 cells/mL: 28.6% vs. 2.1%) than those without malignancy and more patients without malignancy had severe CDI than patients with HM (31.6% vs. 14.3%, P = .003), according to the severity score of IDSA/SHEA. Patients with HM had a higher recurrence rate of CDI (14.3%, 11/77 vs. 7.2%, 17/237; P = .07) and longer hospital stay (47.2 ± 40.8 days vs. 33.3 ± 37.3 days; P = .006) than those without malignancy. In the multivariate analyses for those with HM and CDI, the in-hospital mortality was associated with vancomycin-resistant Enterococcus (VRE) colonization or infection (odds ratio [OR] 7.72; P = .01), and C. difficile ribotype 078 complex infection (OR 9.22; P = .03). Moreover underlying hematological malignancy (OR 2.74; P = .04) and VRE colonization/infection (OR 2.71; P = .02) were independently associated with CDI recurrence.ConclusionPatients with HM complicated with CDI were often regarded as non-severe infection, but had a similar in-hospital mortality rate as those without malignancy. CDI due to ribotype 078 complex isolates heralded a poor prognosis among HM patients.     

Clostridioides difficile colonization among very young children in resource-limited settings

ObjectivesTo describe the epidemiology and risk factors for Clostridioides difficile (C. difficile) colonization among young children in eight low-resource settings.MethodsWe tested 41 354 monthly non-diarrhoeal and diarrhoeal stools for C. difficile toxin genes (TcdA and TcdB) using quantitative PCR (qPCR) in 1715 children from birth to age two years in a multisite birth cohort study. We estimated the prevalence, cumulative incidence, and seasonality of C. difficile colonization and investigated the associations of C. difficile detection with risk factors of infection, markers of enteropathy, and growth.ResultsThe prevalence of C. difficile detection was lower in diarrhoeal (2.2%; n = 151/6731) compared to non-diarrhoeal stools (6.1%; n = 2106/34 623). By 24 months of age, the cumulative incidence of C. difficile varied widely by site, with 17.9% (n = 44; Pakistan) to 76.3% (n = 148; Peru) of children having at least one positive stool. Only Bangladesh and Pakistan had seasonal differences in C. difficile detection. Female sex (adjusted risk ratio (aRR): 1.18; 95% CI: 1.02–1.35), cephalosporin use in the past 15 days (aRR: 1.73; 95% CI: 1.39–2.16), and treated water (aRR: 1.24; 95% CI: 1.02–1.50) were risk factors for C. difficile positivity. The presence of C. difficile was significantly associated with elevated faecal myeloperoxidase, neopterin, and α-1-antitrypsin, but no associations were found between C. difficile and child growth at 24 months of age.DiscussionC. difficile colonization among children ages 0–2 years was variable across low-resource settings. Significant elevation of intestinal inflammation and barrier disruption markers associated with C. difficile detection suggests a subclinical impact of colonization.     

Fast track SSTI management program based on a rapid molecular test (GeneXpert® MRSA/SA SSTI) and antimicrobial stewardship

PurposeThis study examines the impacts of a skin and soft tissue infection (SSTI) management program involving a rapid diagnostic algorithm (Gram stain plus real-time PCR, GeneXpert® MRSA/SA SSTI) performed directly on clinical samples plus antimicrobial stewardship (AMS) counseling of the responsible physician.MethodsParticipants were 155 consecutive adult inpatients with SSTI and good quality clinical samples submitted to the microbiology laboratory from April 2016 to January 2017. Results of the rapid test and AMS recommendations were phoned through to the responsible physician. The comparison group was a historical cohort.ResultsMost SSTI were surgical wound infections (41.3% vs 38.1% for the intervention and comparison groups respectively) followed by diabetic foot (14.2% and 18.1%), abscesses (13.5% both) and cellulitis (12.9% both). Isolated microorganisms were mostly Gram-negative bacilli (two-thirds), followed by Staphylococcus aureus (SA). The ratio methicillin-susceptible SA (MSSA) to methicillin-resistant SA (MRSA) was 4:1. Improvements in the intervention cohort were: DOT (22.0 vs. 24.3 days, p = 0.007), treatment duration per SSTI episode (14.1 vs. 15.0 days, p = 0.072), treatment cost (433.1 vs. 533.3 €, p = 0.039), length of stay (18.6 vs 20.7 days, p = 0.031), related mortality (1 vs. 4 patients, p = 0.022) and Clostridium difficile infection (CDI) (4 vs. 8 patients, p = 0.050). In 48 cases (31.4%) in the intervention group, advice was given to improve empiric antibiotic treatment.ConclusionThis type of program could help adjust antibiotic treatment when inappropriate, reducing antibiotic use and costs, length of stay, CDI and related mortality.     

Clinical characteristics and risk factors for children with norovirus gastroenteritis in Taiwan

BackgroundNorovirus is a common acute gastroenteritis (AGE) pathogen across all age groups worldwide, which is difficult to differentiate from other pathogens. This study aimed to understand the clinical characteristics and risk factors of norovirus gastroenteritis among children in Taiwan.MethodsA prospective AGE surveillance study was conducted in children aged ≤5 years who were hospitalized in 10 major hospitals in Taiwan between 2014 and 2017. The non-AGE control group included healthy children who were matched based on age, gender, season, and geographic area.ResultsOverall, 674 norovirus gastroenteritis patients were enrolled. Fever (p < 0.001), mucoid stool (p < 0.001), and bloody stool (p < 0.001) occurred less frequently among norovirus gastroenteritis patients. Norovirus gastroenteritis patients yielded lower CRP values on admission (21.78 ± 36.81 vs. 46.26 ± 58.12 mg/L, p < 0.001) than non-norovirus controls. Norovirus gastroenteritis patients were associated with higher direct contact rates with AGE patients within 1 week (30.5% vs. 0.97%, p < 0.001), lower hand wash rates before meals (21.6% vs. 15.4%, p = 0.001), lower human milk (15.8% vs. 19.8%, p = 0.045) and guava consumption rates (17.8% vs. 24.3%, p = 0.002) than non-AGE participants.ConclusionsBody temperature, stool characteristics, and CRP value can help distinguish the norovirus from other pathogens. The major risk factor of norovirus AGE is contact with AGE patient. Higher frequency of hand wash, human milk, and guava intake may be protective against norovirus gastroenteritis.     

How to: Clostridioides difficile infection in children

BackgroundClostridioides difficile infections (CDI) are traditionally attributed to an older adult patient group but children can also be affected. Although the causative pathogen is the same in both populations, the management of CDI may differ.ObjectivesTo discuss the current literature on CDI in the paediatric population and to provide CDI diagnostics and treatment guidance.SourcesThe literature was drawn from a search of PubMed from January 2017 to July 2021.ContentIn the paediatric population, laboratory diagnostics for CDI should preferably be combined with laboratory diagnostics for other gastrointestinal pathogens. Coinfections of CDI are also possible. Though the detection of toxigenic C. difficile using a molecular assay may simply reflect colonisation rather than infection, detection of C. difficile free toxins A/B in faeces is much more indicative of true infection. CDI in children below 2 years of age and in the absence of risk factors is very difficult to diagnose and requires careful clinical judgement pending additional studies.Fidaxomicin has been shown to be superior to vancomycin with a sustained clinical response up to 30 days after the end of CDI treatment in children. Metronidazole is less effective than vancomycin in adults and there are no supporting data for its use in children. In recurrent CDI, treatment should be adjusted according to the drug or drug regimen used for the treatment of a previous episode(s). In multiple recurrent CDI, faecal microbiota transplantation can be effective.ImplicationsIf CDI laboratory testing is indicated in children with diarrhoea, the likelihood of C. difficile colonisation and coinfection with other intestinal pathogens should be considered. The currently available data support a change in the treatment strategy of CDI in children.     

Asymptomatic Clostridium difficile carriage rate post-fecal microbiota transplant is low: a prospective clinical and stool assessment

ObjectivesWe aimed to assess the asymptomatic Clostridium difficile carriage rates following fecal microbiota transplantation (FMT).MethodsAll patients who underwent FMT for recurrent Clostridium difficile infection (CDI) via colonoscopy or sigmoidoscopy between June 2013 and April 2015 and had a minimum of 8-week follow-up post FMT at two tertiary care referral centres were included in the study. Patients were prospectively followed both clinically and with stool assessments for 8 weeks post FMT. Assessments occurred at 1 week and 4 weeks post FMT to assess for failure. Failure was defined as presence of diarrhoeal symptoms and a positive CDI stool test by polymerase chain reaction for toxin gene (PCR) at any time point during the 8-week follow-up period. CDI stool testing using PCR was performed at weeks 1 and 4 post FMT in asymptomatic patients as well.Results167 patients were included. Twenty-eight patients (16.7% (28/167)) were FMT failures throughout the 8-week period. At week 1, seven patients had already failed the FMT. Of the remaining 160 patients, 144 were asymptomatic, and among these, 141 were negative for C. difficile toxin gene by PCR. This resulted in an asymptomatic carriage rate of 2.1% (3/144). At week 4, 143 patients had not yet failed FMT. Of these patients 129 patients were asymptomatic and among those, 125 were negative by PCR, resulting in an asymptomatic carriage rate of 3% (3/129).ConclusionsAsymptomatic carriage after FMT is rare. This suggests that testing for cure after FMT in asymptomatic patients is not necessary.     

Clostridium difficile and One Health

BackgroundFor over four decades, Clostridium difficile has been a significant enteric pathogen of humans. It is associated with the use of antimicrobials that generally disrupt the microbiota of the gastrointestinal tract. Previously, it was thought that C. difficile was primarily a hospital-acquired infection; however, with the emergence of community-associated cases, and whole-genome sequencing suggesting the majority of the hospital C. difficile infection (CDI) cases are genetically distinct from one another, there is compelling evidence that sources/reservoirs of C. difficile outside hospitals play a significant role in the transmission of CDI.ObjectivesTo review the ‘One Health’ aspects of CDI, focusing on how community sources/reservoirs might be acting as a conduit in the transfer of C. difficile between animals and humans. The importance of a One Health approach in managing CDI is discussed.SourcesA literature search was performed on PubMed and Web of Science for relevant papers published from 1 January 2000 to 10 July 2019.ContentWe present evidence that demonstrates transmission of C. difficile in hospitals from asymptomatic carriers to symptomatic CDI patients. The source of colonization is most probably community reservoirs, such as foods and the environment, where toxigenic C. difficile strains have frequently been isolated. With high-resolution genomic sequencing, the transmission of C. difficile between animals and humans can be demonstrated, despite a clear epidemiological link often being absent. The ways in which C. difficile from animals and humans can disseminate through foods and the environment are discussed, and an interconnected transmission pathway for C. difficile involving food animals, humans and the environment is presented.ImplicationsClostridium difficile is a well-established pathogen of both humans and animals that contaminates foods and the environment. To manage CDI, a One Health approach with the collaboration of clinicians, veterinarians, environmentalists and policy-makers is paramount.     

Relationship between remote cholecystectomy and incident Clostridioides difficile infection

ObjectivesCholecystectomy (CCY) is associated with increased faecal levels of secondary bile acids. Secondary bile acids confer resistance to Clostridioides difficile infection (CDI, formerly Clostridium difficile infection) in animal studies. This study tested the hypothesis that CCY confers protection against CDI by increasing gut levels of secondary bile acids.MethodsThis was a retrospective case–control study. Adults hospitalized between January 2010 and June 2017 at our institution were included. CDI cases were defined as a positive stool PCR followed by anti-CDI treatment and were matched 1:1:1 with two control groups (those who tested negative for CDI and those who were not tested for CDI) by sex, age group, body mass index (BMI), and exposure to antibiotics. CCY was defined as a history of CCY at least 6 months prior to the index C. difficile test or the index admission date in the untested controls. Conditional logistic regression modelling was used to estimate the relationship between remote CCY and risk for CDI.ResultsThe final study population was 7077 (2359 CDI cases, 2359 matched controls without CDI, and 2359 matched controls not tested for CDI). Rates of remote CCY did not differ among the three groups (14.4% vs. 15.5% vs. 14.2%) and this result was unchanged after adjusting for additional clinical factors (adjusted OR 0.90, 95% CI 0.76–1.06 comparing CDI cases vs. matched controls without CDI; adjusted OR 1.04, 95% CI 0.78–1.39 comparing CDI cases vs. matched controls not tested for CDI).ConclusionsThere was no association between remote CCY and risk for CDI.     

Microbiologic factors affecting Clostridium difficile recurrence

BackgroundRecurrent Clostridium difficile infection (rCDI) places a huge economic and practical burden on healthcare facilities. Furthermore, rCDI may affect quality of life, leaving patients in an rCDI cycle and dependant on antibiotic therapy.AimsTo discuss the importance of microbiologic factors in the development of rCDI.SourcesLiterature was drawn from a search of PubMed from 2000 onwards with the search term ‘recurrent Clostridium difficile infection’ and further references cited within these articles.ContentMeta-analyses and systematic reviews have shown that CDI and rCDI risk factors are similar. Development of rCDI is attendant on many factors, including immune status or function, comorbidities and concomitant treatments. Studies suggest that poor bacterial diversity is correlated with clinical rCDI. Narrow-spectrum gut microflora-sparing antimicrobials (e.g. surotomycin, cadazolid, ridinilazole) are in development for CDI treatment, while microbiota therapeutics (faecal microbiota transplantation, nontoxigenic C. difficile, stool substitutes) are increasingly being explored. rCDI can only occur when viable C. difficile spores are present, either within the gut lumen after infection or when reacquired from the environment. C. difficile spore germination can be influenced by gut environmental factors resulting from dysbiosis, and spore outgrowth may be affected stage by some antimicrobials (e.g. fidaxomicin, ramoplanin, oritavancin).ImplicationsrCDI is a significant challenge for healthcare professionals, requiring a multifaceted approach; optimized infection control to minimize reinfection; C. difficile–targeted antibiotics to minimize dysbiosis; and gut microflora restoration to promote colonization resistance. These elements should be informed by our understanding of the microbiologic factors involved in both C. difficile itself and the gut microbiome.     

Ribotype 027 Clostridium difficile infections with measurable stool toxin have increased lactoferrin and are associated with a higher mortality

We evaluated clinical and diagnostic indicators of severe C. difficile infection (CDI) and their association with poor clinical outcome. A total of 210 patients positive according to PCR (toxin B: tcdB) were included, with patients having a median age of 62 years and a Charlson co-morbidity index (CI) score of 5. Ninety-one percent (n?=?191) were positive by toxigenic culture and 61 % (n?=?129) had stool toxin. Toxin-positive patients had significantly higher fecal lactoferrin (mean 316 μg/g versus 106 μg/g stool; p?<?0.0001). Forty percent of patients (n?=?85) were infected with ribotype 027 and significantly more of these patients had measurable stool toxin (79 % vs. 50 %; p?<?0.0001). The mean fecal lactoferrin was significantly higher for toxin-positive 027 CDI compared with the 027 toxin-negative group (317 vs 60 μg/g; p?=?0.0014). Ribotype 027 CDI with stool toxin showed a higher all-cause, 100-day mortality compared with non-027 with stool toxin (36 % vs 18 %; p?=?0.017). Logistic regression univariate analysis for odds ratio (OR) and p values revealed that age (OR?=?1.1), intensive care unit treatment (OR?=?2.7), CI (OR?=?1.2), 027 CDI (OR?=?2.1), white blood cell count (OR?=?1.0), albumin level (OR?=?0.1), and stool toxin-positive 027 CDI (OR?=?2.5) were significantly associated with 100-day mortality (p?<?0.05). In conclusion, CDI PCR-positive patients with 027 infection and stool toxin have increased lactoferrin and are at an increased risk of death.     

Ceftriaxone versus ampicillin for the treatment of community-acquired pneumonia. A propensity matched cohort study

ObjectivesCeftriaxone is recommended as first-line antibiotic treatment (with the addition of macrolide) for hospitalised adults with community acquired pneumonia (CAP). Narrower-spectrum β-lactam as ampicillin, may be associated with comparable clinical outcomes, with less emergence of resistant pathogens or Clostridioides difficile infection (CDI). We aimed to examine whether ampicillin and ceftriaxone (with the addition of macrolides for both arms) are comparable for the treatment of hospitalized adults due to CAP.MethodsThis was a single center, observational cohort study. We included adult patients who were hospitalized in internal medicine wards due to CAP and were treated with either ceftriaxone or ampicillin with the addition of macrolide. A propensity-score model was used. The primary outcome was 30-day all-cause mortality. A multivariable logistic regression analysis and Kaplan-Meier survival analysis was performed. We performed subgroup analyses for the main outcome based on CURB-65 score and age.ResultsA total of 1586 patients fulfilled the inclusion criteria. There was no difference in 30-day mortality rate in the total cohort (28/233 vs. 208/1353 in ampicillin and ceftriaxone arm, respectively; p = 0.184). In the propensity matched cohort (197 in ampicillin and 394 in ceftriaxone arm), there was no significant difference in 30-day all-cause mortality between treatment groups in multivariable analysis of the main model (OR 0.67, 95% CI, 0.37–1.2; p = 0.189) and Kaplan-Meier survival analysis (p = 0.108). Thirty-day mortality rate was (19/197 vs. 57/394, in ampicillin and ceftriaxone arms, respectively; p = 0.108) Patients who were treated with ampicillin experienced significantly lower rates of CDI (0/197, 0% vs. 8/394, 2%; p = 0.044).DiscussionAmpicillin was associated with comparable clinical outcomes in comparison to ceftriaxone for patients who were hospitalized due to CAP. Ampicillin was associated with significantly lower rate of CDI. Results need to be confirmed by more robust study designs.     

Elevated lactoferrin is associated with moderate to severe Clostridium difficile disease, stool toxin, and 027 infection

We evaluated blood and fecal biomarkers as indicators of severity in symptomatic patients with confirmed Clostridium difficile infection (CDI). Recruitment included patients with CDI based on clinical symptoms and supporting laboratory findings. Disease severity was defined by physician’s assessment and blood and fecal biomarkers were measured. Toxigenic culture done using spore enrichment and toxin B detected by tissue culture were done as confirmatory tests. Polymerase chain reaction (PCR) ribotyping was performed on each isolate. There were 98 patients recruited, with 85 (87 %) confirmed cases of toxigenic CDI (21 severe, 57 moderate, and seven mild), of which 68 (80 %) were also stool toxin-positive. Elevated lactoferrin (p?=?0.01), increased white blood cell (WBC) count (p?=?0.08), and low serum albumin (p?=?0.03) were all associated with the more severe cases of CDI. Ribotype 027 infection accounted for 71 % of severe cases (p?<?0.01) and patients with stool toxin had significantly higher lactoferrin levels and WBC counts (p?<?0.05). Our findings show that elevated fecal lactoferrin, along with increased WBC count and low serum albumin, were associated with more severe CDI. In addition, patients infected with ribotype 027 and those with stool toxin had significantly higher fecal lactoferrin and WBC counts.     

Environmental shedding of toxigenic Clostridioides difficile by asymptomatic carriers: A prospective observational study

ObjectivesThe aim was to compare the burden of environmental shedding of toxigenic Clostridioides difficile among asymptomatic carriers, C. difficile-infected (CDI) patients and non-carriers in an inpatient non-epidemic setting.MethodsC. difficile carriage was determined by positive toxin-B PCR from rectal swabs of asymptomatic patients. Active CDI was defined as a positive two-step enzyme immunoassay/polymerase chain reaction (EIA/PCR) test in patients with more than three unformed stools/24 hr. C. difficile environmental contamination was assessed by obtaining specimens from ten sites in the patients' rooms. Toxigenic strains were identified by PCR. We created a contamination scale to define the overall level of room contamination that ranged from clean to heavy contamination.ResultsOne hundred and seventeen rooms were screened: 70 rooms inhabited by C. difficile carriers, 30 rooms by active CDI patients and 17 rooms by non C. difficile -carriers (control). In the carrier rooms 29 (41%) had more than residual contamination, from which 17 (24%) were heavily contaminated. In the CDI rooms 12 (40%) had more than residual contamination from which three (10%) were heavily contaminated, while in the control rooms, one room (6%) had more than residual contamination and none were heavily contaminated. In a multivariate analysis, the contamination score of rooms inhabited by carriers did not differ from rooms of CDI patients, yet both were significantly more contaminated than those of non-carriers odd ratio 12.23 and 11.16 (95% confidence interval 1.5–99.96 p 0.0195, and 1.19–104.49 p 0.035), respectively.DiscussionHere we show that the rooms of C. difficile carriers are as contaminated as those of patients with active CDI and significantly more than those of non-carriers.     

Genome engineering of Clostridium difficile using the CRISPR-Cas9 system

ObjectivesClostridium difficile is a notorious pathogenic species that can cause severe gastrointestinal infections in humans and animals. C. difficile infection (CDI) results in thousands of deaths worldwide every year. The elucidation of related mechanisms of CDI and exploration of potential therapeutic strategies are largely delayed due to the lack of efficient genetic engineering tools for C. difficile strains.MethodsPlasmids carrying the CRISPR-Cas9 system were constructed and transformed into C. difficile through conjugation. Mutants were identified using colony PCR with primers annealing to the regions flanking the target gene deletion/integration locus. Heat-survival assay was used to compare the sporulation frequency between the mutant with spo0A deletion and the wild type strain. The fluorescence in the mutant with the insertion of the green fluorescent protein (GFP) gene was inspected under a fluorescent microscope.ResultsAn efficient genome editing tool was developed for C. difficile based on the CRISPR-Cas9 system. With this tool, spo0A was deleted with a 100% mutation efficiency. Conversely, an anaerobic GFP gene was successfully inserted into the C. difficile chromosome (with a mutation efficiency of 80%).ConclusionsThe developed CRISPR-Cas9-based genome engineering tool will facilitate functional genomic studies in C. difficile as well as the elucidation of mechanisms related to host–bacteria interaction and pathogenesis of CDI. This will be highly beneficial for the development of innovative strategies for CDI diagnostics and therapies.     

Association between histo-blood group antigens and Pseudomonas aeruginosa-associated diarrheal diseases

BackgroundPseudomonas aeruginosa is not a common enteric pathogen. The association between human histo-blood group antigens (HBGAs) and P. aeruginosa enteric infection has not yet been studied.MethodsWe collected stool samples from healthy children under 2 years of age for P. aeruginosa gut colonization rate. Saliva samples were collected from patients with P. aeruginosa-associated diarrheal diseases and normal healthy children. Genomic DNA was extracted from saliva samples for ABO blood group typing and FUT2 genotyping. Lewis phenotype was detected using ELISA assay.ResultsA total of 85 patients with P. aeruginosa-associated diarrheal diseases and 105 healthy children were enrolled for collecting saliva specimens. The stool colonization rate was 5/101 (5%) in healthy children, 4/58 (6.9%) in infants, and 1/43 (2.3%) in children 1–2 years old, respectively. Blood group A was more frequent in patients with P. aeruginosa-associated diarrheal diseases 24/77 (31.2%) than in healthy children 18/102 (17.6%) (P = 0.035). All patients and healthy children were secretor positive. The distribution of weak-secretor genotype Se³⁸⁵/Se³⁸⁵ was 23/84 (27.4%) in patients with P. aeruginosa-associated diarrheal diseases and 17/104 (16.3%) in healthy children, respectively (P = 0.06). Patients with P. aeruginosa-associated diarrheal diseases had a higher percentage of Le^a+b+ phenotype 25/81 (30.9%) than healthy children 17/105 (16.2%) (P = 0.018). There was no association between ABO or secretor or Lewis status with the clinical severity of P. aeruginosa-associated diarrheal diseases.ConclusionInfants had a higher gut P. aeruginosa colonization rate than children. Children with blood group A and Le^a+b+ phenotype are prone to P. aeruginosa-associated diarrheal diseases.     

Toxigenic Clostridium difficile carriage in general practice: results of a laboratory-based cohort study

ObjectivesReported rates of community-acquired Clostridium difficile infections (CDIs) have been increasing. However, the true burden of the disease in general practice is unknown in France. Our objective was to determine the incidence of toxigenic C. difficile carriage and the percentage of stool samples prescribed by general practitioners (GPs) which contained free C. difficile toxins.MethodsDuring an 11-month period, all stool samples submitted for any enteric pathogen detection to 15 different private laboratories in Paris and the surrounding areas were tested for C. difficile, irrespective of the GPs' request. A clinical questionnaire was completed for each patient. Stool samples were screened using a rapid simultaneous glutamate dehydrogenase and toxins A/B detection test: any positive result (glutamate dehydrogenase or toxin) was further confirmed by the stool cytotoxicity assay (CTA) on MRC-5 cells and by toxigenic culture (TC) at a central laboratory. The C. difficile isolates were characterized by PCR ribotyping.ResultsA total of 2541 patients (1295 female, 1246 male) were included. The incidences of patients with a positive toxigenic culture and a positive CTA were 3.27% (95% CI 2.61%–4.03%) and 1.81% (95% CI 1.33%–2.41%), respectively. GPs requested C. difficile testing in only 12.93% of the stool samples, detecting 52.30% of all TC-positive patients. The 83 toxigenic C. difficile strains belonged to 36 different PCR ribotypes.ConclusionsToxigenic C. difficile carriage is frequent in general practice but remains under-recognized. It may affect young patients without previous antimicrobial therapy or hospitalization.     

Host factors are more important in predicting recurrent Clostridium difficile infection than ribotype and use of antibiotics

ObjectiveA frequent complication of Clostridium difficile infection (CDI) is recurrent disease. The aim of this study was to determine whether early recurrence risk was higher after infection with ribotype 027 (outbreak strain) compared with infection with endemic strain types of C. difficile.MethodsConsecutive patients diagnosed with CDI between May 2013 and March 2014 were included (outbreak strain, and non-outbreak strains). Patients who developed recurrent CDI within 30 days after completion of CDI treatment, were compared with patients without a recurrence. Medical charts were reviewed for demographic and clinical characteristics. General practitioners were contacted to complete data about the occurrence of recurrent CDI, and the use of medication after hospital discharge.ResultsIn total, 135 patients were at risk for the development of recurrent CDI; 74 patients were infected by ribotype 027, and 61 patients by other ribotypes. Thirty-nine patients (29%) developed recurrent CDI within 30 days after completion of CDI treatment. In multivariable analysis, age ≥70 years (HR 3.05, 95% CI 1.54–6.03), and a duration of CDI treatment ≥11 days (HR 1.92, 95% CI 1.00–3.69) were clearly associated with recurrence; infection with ribotype 027 showed a HR of 1.72 (95% CI 0.88–3.33).ConclusionDuring this outbreak of C. difficile in a tertiary care centre, age and a prolonged duration of CDI therapy (which is most likely a marker of underlying disease severity) were the main risk factors for recurrent CDI. This points to host factors as more important predictors for recurrent CDI than strain type or antibiotic use.     

Prognosis of <Emphasis Type="Italic">Clostridium difficile</Emphasis> infection in adult oncohaematological patients: experience from a large prospective observational study

The aim of the study is to evaluate demographics, epidemiology, clinical characteristics, treatment and outcomes of Clostridium difficile infection (CDI) in patients with and without concurrent cancer. This is a prospective cohort study of consecutive primary CDI episodes in adults (January 2006–December 2016). CDI was diagnosed on the presence of diarrhoea and positive stool testing for toxigenic C. difficile. Univariate analysis assessed differences between cancer and non-cancer patients. Risk factors of all-cause 30-day mortality were determinate using the logistic multivariable procedure. In total, 787 CDI episodes were recorded, 191 in cancer patients (median age 64, IQR 50–73). Of these, 120 (63%) had solid and 71 (37%) haematological malignancies (24 received a stem cell transplant). At the CDI diagnosis, 158 (82.7%) cancer patients had prior antibiotics and 150 (78.5%) were receiving proton pump inhibitors. Fifty-seven (80.3%) patients with haematological and 52 (43.3%) with solid malignancies were under chemotherapy at diagnosis; 25 (35.2%) with haematological and 11 (9.2%) with solid malignancies had an absolute neutrophil count <?1000/mm³. Overall, 30-day mortality was higher in cancer patients than in those without (19.2 vs. 8.6% respectively, p?<?0.001); recurrence rates did not vary significantly (11.1 vs. 11%, p?=?0.936). By type of neoplasm, 30-day mortality was higher in patients with haematological malignancies and solid tumours than in patients without cancer (respectively, 25.4 vs. 8.6%; p?<?0.001 and 15 vs. 8.6%; p?<?0.001). Our results suggest that the prognosis of CDI (30-day mortality) is poorer in patients with cancer than in those without although percentages of recurrent infection are similar in these two patient populations.     

The incidence and clinical symptomatology of Clostridium difficile infections in a community setting in a cohort of Danish patients attending general practice

Clostridium difficile infection (CDI) is gradually being recognised as a cause of morbidity in the community. We investigated the incidence and clinical characteristics of CDI in a community setting and characterised the C. difficile strains by toxin gene profiling and polymerase chain reaction (PCR) ribotyping. Patients included in the study had attended general practice, primarily because of diarrhoea; CDI patients (259 patients; 121 <2 years of age) had positive cultures for toxigenic C. difficile and non-CDI patients (455 patients) were culture-negative. Outcome variables included the frequency and duration of diarrhoea, vomiting, stomach ache, fever >38 °C, weight loss and sick leave. Data were analysed by logistic regression. CDI patients <2 and ≥2 years of age with C. difficile as the only enteropathogen in the faecal sample reported slimy stools (65 % vs. 62 %), stomach ache (60 % vs. 75 %), weight loss (50 % vs. 76 %) and duration of diarrhoea >15 days (59 % vs. 73 %) as the predominant symptoms. CDI patients ≥2 years old reported duration of diarrhoea >15 days more often compared to non-CDI patients (73 % vs. 27 %, p?<?0.0001). The annual incidence of CDI was 518 and 23/100,000 for patients <2 and ≥2 years of age, respectively, and 46/100,000 in the subgroup of patients ≥60 years of age. CDI was characterised by stomach ache and persistent diarrhoea, often leading to weight loss. This emphasises the importance of diagnosing CDI not only in hospitalised patients, but also in individuals ≥2 years of age attending general practice because of gastrointestinal symptoms, especially in the elderly, where the incidence of CDI is high.