Soraya Cherifi

Comparative Epidemiology of Staphylococcus epidermidis Isolates from Patients with Catheter-Related Bacteremia and from Healthy Volunteers

ABSTRACT Staphylococcus epidermidis is a major cause of catheter-related bloodstream infections (CRBSIs). Recent studies suggested the existence of well-adapted, highly resistant, hospital-associated S. epidermidis clones. The molecular epidemiology of S. epidermidis in Belgian hospitals and the Belgian community has not been explored yet. We compared a set of 33 S. epidermidis isolates causing CRBSI in hospitalized patients with a set of 33 commensal S. epidermidis isolates. The factors analyzed included resistance to antibiotics and genetic diversity as determined by pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and SCCmec typing. Additionally, the presence of virulence-associated mobile genetic elements, the ica operon and the arginine catabolic mobile element (ACME), was assessed and compared against clinical data. CRBSI S. epidermidis isolates were significantly resistant to more antibiotics than commensal S. epidermidis isolates. The two populations studied were very diverse and genetically distinct as only 23% of the 37 PFGE types observed were harbored by both CRBSI and commensal isolates. ACME was found in 76% of S. epidermidis strains, regardless of their origin, while the ica operon was significantly more prevalent in CRBSI isolates than in commensal isolates (P < 0.05). Nine patients presented a clinically severe CRBSI, eight cases of which were due to an ica-positive multiresistant isolate belonging to sequence type 2 (ST2) or ST54. S. epidermidis isolates causing CRBSI were more resistant and more often ica positive than commensal S. epidermidis isolates, which were genetically heterogeneous and susceptible to the majority of antibiotics tested. Clinically severe CRBSIs were due to isolates belonging to two closely related MLST types, ST2 and ST54.

SACCHAROMYCES CEREVISIAE FUNGEMIA IN AN ELDERLY PATIENT WITH CLOSTRIDIUM DIFFICILE COLITIS

Abstract Saccharomyces boulardii is widely used as a probiotic compound and is generally thought to be safe. We report one case of fungemia caused by Saccharomyces cerevisiae occurring in an elderly patient treated orally with S. boulardii in association with vancomycin for Clostridium difficile colitis. We do not recommend administering this viable yeast particularly in debilited patient with active colitis.

Management of an Outbreak of Clostridium difficile–Associated Disease Among Geriatric Patients

OBJECTIVE To describe a nosocomial outbreak of Clostridium difficile-associated disease (CDAD). DESIGN A traditional outbreak investigation. SETTING Geriatric department of a tertiary care teaching hospital from March through April 2003. METHODS The outbreak was detected by the C. difficile surveillance program of the infection control unit. CDAD was diagnosed by stool culture and fecal toxin A detection with a qualitative rapid immunoassay. Isolates of C. difficile were serotyped and genotyped using pulsed-field gel electrophoresis. RESULTS The incidence of CDAD increased from 27 cases per 100,000 patient-days in the 6-month period before the outbreak to 99 cases per 100,000 patient-days during the outbreak. This outbreak involved 21 of 92 patients in 4 geriatric wards, which were located at 2 geographically distinct sites and staffed by the same medical team. The mean age of patients was 83 years (range, 71-100 years). Five (24%) of the 21 patients had community-acquired diarrhea, and secondary hospital transmission resulted in 3 clusters involving 16 patients. Serotyping and genotyping were performed on isolates in stool specimens from 19 different patients; 16 of these isolates were serotype A1, whereas 3 displayed profiles different from the outbreak strain. Management of this outbreak consisted in reinforcement of contact isolation precautions for patients with diarrhea, cohorting of infected patients in the same ward, and promotion of hand hygiene. Relapses occurred in 6 (29%) of 21 patients. CONCLUSION Control of this rapidly developing outbreak of CDAD was obtained with early implementation of cohorting and ward closure and reinforcement of environmental disinfection, hand hygiene, and enteric isolation precautions.

Genetic characteristics and antimicrobial resistance of Staphylococcus epidermidis isolates from patients with catheter-related bloodstream infections and from colonized healthcare workers in a Belgian hospital

BackgroundStaphylococcus epidermidis is a pathogen that is frequently encountered in the hospital environment. Healthcare workers (HCWs) can serve as a reservoir for the transmission of S. epidermidis to patients.MethodsThe aim of this study was to compare and identify differences between S. epidermidis isolated from 20 patients with catheter-related bloodstream infections (CRBSIs) and from the hands of 42 HCWs in the same hospital in terms of antimicrobial resistance, biofilm production, presence of the intercellular adhesion (ica) operon and genetic diversity (pulsed field gel electrophoresis (PFGE), multilocus sequence typing (MLST) and staphylococcal cassette chromosome (SCC) mec typing).ResultsS. epidermidis isolates that caused CRBSI were resistant to significantly more non-betalactam drugs than were isolates collected from HCWs. Among the 43 mecA positive isolates (26 from HCWs), the most frequent SCCmec type was type IV (44%). The ica operon was significantly more prevalent in CRBSI isolates than in HCWs (P < 0.05). Weak in vitro biofilm production seemed to correlate with the absence of the ica operon regardless of the commensal or pathogenic origin of the isolate. The 62 isolates showed high diversity in their PFGE patterns divided into 37 different types: 19 harbored only by the CRBSI isolates and 6 shared by the clinical and HCW isolates. MLST revealed a total of ten different sequence types (ST). ST2 was limited to CRBSI-specific PFGE types while the “mixed” PFGE types were ST5, ST16, ST88 and ST153.ConclusionOne third of CRBSI episodes were due to isolates belonging to PFGE types that were also found on the hands of HCWs, suggesting that HCW serve as a reservoir for oxacillin resistance and transmission to patients. However, S. epidermidis ST2, mecA- positive and icaA-positive isolates, which caused the majority of clinically severe CRBSI, were not recovered from the HCW’s hands.

A multicenter quasi-experimental study: impact of a central line infection control program using auditing and performance feedback in five Belgian intensive care units.

BackgroundWe analyzed the impact associated with an intervention based on process control and performance feedback to decrease central line-associated bloodstream infection (CLABSI) rates.This study was conducted from March 2011 to September 2012 in five adult intensive care units (ICU) located in two Belgian tertiary hospitals A and B, with a total of 53 beds.MethodsThis study was divided in three phases: P1 (baseline), P2 (intervention) and P3 (post intervention).During P2, external monitoring of five central venous catheters (CVC) care critical processes and monthly reporting (meetings and feedbacks reports posted) of performance indicators (CLABSI rate, CVC utilization ratio, compliance rate with each care process, and insertion site) to ICU workers were performed. The external monitoring of process measures was assessed by the same trained research nurse.A Poisson regression analysis was used to compare CLABSI incidence density rate per phase. Statistical significance was achieved with 2-sided p- value of < 0.05. For the analysis, we separated the five ICU in hospital A and B when appropriate.ResultsSignificantly improved total mean compliance was achieved for hand hygiene, CVC handling and CVC dressing. CLABSI rate declined from 4.00 (95% confidence interval (CI): 1.94-6.06) to 1.81 (0.46-3.17) per 1,000 CVC-days in P2 with an incidence rate ratio (IRR) of 0.49 (0.24-0.98, p = 0.043). A better response was observed in hospital A where the nurse participation at the monthly meeting was significantly higher than in hospital B (p < 0.001) as the percentage of feedbacks reports posted in ICU (p < 0.001). The decline in the CLABSI rate observed during P2 in comparison with P1 was independent of the insertion site (femoral or non-femoral; p = 0.054). The overall CLABSI rate increased to 2.73 (1.17-4.29) per 1,000 CVC-days with IRR of 0.67 (0.36-1.26, p = 0.212) in P3 compared to P1, but a high nursing turnover was observed in both hospitals.ConclusionsOur intervention focused on external auditing and performance feedback resulted in significant reduction in rates of CLABSI. Investigation continues regarding the most effective way to sustain CLABSI prevention practices and to improve the culture of safety in healthcare.

Variations in catheter-related bloodstream infections rates based on local practices

BackgroundCatheter-related bloodstream infection (CRBSI) surveillance serves as a quality improvement measure that is often used to assess performance. We reviewed the total number of microbiological samples collected in three Belgian intensive care units (ICU) in 2009–2010, and we described variations in CRBSI rates based on two factors: microbiological documentation rate and CRBSI definition which includes clinical criterion for coagulase-negative Staphylococcus (CNS) episode.FindingsCRBSI rates were 2.95, 1.13 and 1.26 per 1,000 estimated catheter-days in ICUs A, B and C, respectively. ICU B cultured fewer microbiological samples and reported the lowest CRBSI rate. ICU C had the highest documentation rate but was assisted by support available from the laboratory for processing single CNS positive blood cultures. With the exclusion of clinical criterion, CRBSI rates would be reduced by 19%, 45% and 0% in ICUs A, B and C, respectively.ConclusionCRBSI rates may be biased by differences of blood culture sampling and CRBSI definition. These observations suggest that comparisons of CRBSI rates in different ICUs remain difficult to interpret without knowledge of local practices.

Hospital preparedness and clinical description of the 2009 influenza A (H1N1) pandemic in a Belgian tertiary hospital

We describe hospital preparedness, including costs, and clinical characteristics of the 2009 influenza A (H1N1) pandemic in adult patients in a Belgian tertiary care centre. A task force coordinated the overall management, including triage and hospitalisation. Between 1 June and 30 November 2009, 521 patients with influenza-like illness were admitted to the emergency ward. We reviewed data from 43 hospitalised patients with confirmed influenza A. Median age was 44 years (range: 21-79), with 84% patients having underlying disease. Eleven needed admission to intensive care unit (ICU) and one patient died. The financial impact of the epidemic was estimated at €75,691, and approximately half of these costs were related to the enhanced infection control practices. The Belgian 2009 influenza A (H1N1) pandemic, as described in a cohort of 43 hospitalised patients, was associated with a relatively high ICU admission rate of 26% and a fairly typical mortality rate of 3%. This retrospective study may help us refine the management of future epidemics.

Management and outcome of high-risk peritonitis: a retrospective survey 2005-2009.

OBJECTIVES To describe the clinical and microbiological aspects of high-risk peritonitis and to analyze their impact on its outcome. METHODS This was a retrospective review of all culture-positive peritonitis between October 1, 2005 and September 30, 2009. In accordance with recent Infectious Diseases Society of America (IDSA) guidelines, a group of high-risk peritonitis patients was selected based on age, severity of illness, underlying diseases, and acquisition of the infection. RESULTS Ninety-three patients with high-risk peritonitis were studied; these patients were divided into subgroups of those with community-associated disease (14%) and those with healthcare-associated disease (86%). The median age of patients was 66 (interquartile range (IQR) 22-95) years. The 30-day mortality rate was 25%. Subgroups differed in age (p=0.011), degree of comorbidity (p=0.023), severity of peritonitis (p=0.036), admission to the intensive care unit (ICU) (p=0.002), length of ICU stay (p<0.001), length of hospital stay (p<0.001), cure at day 30 (p=0.001), and adequate treatment (p=0.042). The microbiological etiology and resistance profiles were similar between the patient groups. Adequate empirical treatment was not related to a better outcome. Severity of disease (p=0.005) and the presence of enterococci (p=0.044) were independently associated with mortality. CONCLUSIONS The mode of acquisition influences severity and certain parameters of outcome in high-risk peritonitis, but not its microbiological etiology. The outcome seems to depend primarily on severity of peritonitis and much less on the adequacy of treatment.

Upper gastrointestinal bleeding related to emphysematous cholecystitis due to Clostridium perfringens

We describe the case of a 46-year-old man admitted for upper gastrointestinal bleeding in the context of cirrhosis. A deep bleeding duodenal ulcer was treated by sclerotherapy. Abdominal pain and fever lead us to perform an abdominal computed tomography, which demonstrated emphysematous cholecystitis. An emergency cholecystectomy was performed and antimicrobial therapy initiated. The patient recovered uneventfully. Links between ulcers and emphysematous cholecystitis are discussed.