Understanding the diagnosis of catheter-related bloodstream infection: real-time monitoring of biofilm growth dynamics using time-lapse optical microscopy

Background

The differential time to positivity (DTTP) technique is recommended for the conservative diagnosis of catheter-related bloodstream infection (C-RBSI). The technique is based on a 120-minute difference between microbial growth in blood drawn through the catheter and blood drawn through a peripheral vein. However, this cut-off has failed to confirm C-RBSI caused by Candida spp. and Staphylococcus aureus.

Objective

We hypothesized that the biofilm of both microorganisms disperses faster than that of other microorganisms and that microbial load is rapidly equalized between catheter and peripheral blood. Therefore, our aim was to compare the biofilm dynamics of various microorganisms.

Methods

Biofilm of ATCC strains of methicillin-resistant Staphylococcus epidermidis, methicillin-susceptible S. aureus, Enterococcus faecalis, Escherichia coli and Candida albicans was grown on silicon disks and analyzed using time-lapse optical microscopy. The time-lapse images of biofilms were processed using ImageJ2 software. Cell dispersal time and biofilm thickness were calculated.

Results

The mean (standard deviation) dispersal time in C. albicans and S. aureus biofilms was at least nearly 3 hours lower than in biofilm of S. epidermidis, and at least 15 minutes than in E. faecalis and E. coli biofilms.

Conclusion

Our findings could explain why early dissemination of cells in C. albicans and S. aureus prevents us from confirming or ruling out the catheter as the source of the bloodstream infection using the cut-off of 120 minutes in the DTTP technique. In addition, DTTP may not be sufficiently reliable for E. coli since their dispersion time is less than the cut-off of 120 minutes.

Lower risk of bloodstream infections for peripherally inserted central catheters compared to central venous catheters in critically ill patients

Background

Peripherally inserted central venous catheters (PICCs) serve as an alternative to short-term central venous catheters (CVCs) for providing intravenous access in hospitalized patients. Although a number of studies suggest that PICCs are associated with a lower risk of central line-associated bloodstream infections (CLABSIs) than CVCs, recent data concerning specific patient groups support the contrary. In this regard, we are comparing CVC- and PICC-related CLABSI rates developed in a selected group of critically ill inpatients and evaluating the CLABSI microbiological distribution.

Methods

The study was conducted at a tertiary care hospital in Greece between May 2017 and May 2019. We performed a two-year retrospective analysis of the data collected from medical records of consecutive adult patients who underwent PICC or CVC placement.

Results

A total of 1187 CVCs placed for 9774 catheter-days and 639 PICCs placed for 11,110 catheter-days, were reported and analyzed during the study period. Among CVCs, a total of 59 (4.9%) CLABSIs were identified, while among PICCs, 18 (2.8%) cases presented CLABSI (p = 0.029). The CLABSI incidence rate per 1,000 catheter-days was 6.03 for CVC group and 1.62 for PICC group (p < 0.001). The CLABSI rate due to multidrug-resistant organisms (MDROs) among the two groups was 3.17 in CVC group and 0.36 in PICC group (p < 0.001). Within CLABSI-CVC group, the most common microorganism detected was MDR Acinetobacter baumannii (27.1%) followed by MDR Klebsiella pneumoniae (22%). In CLABSI-PICC group, the predominant microorganism was Candida spp. (33.3%) followed by non-MDR gram-negative pathogens (22.2%).

Conclusions

PICC lines were associated with significantly lower CLABSI rates comparing to CVC although they were in place longer than CVC lines. Given their longer time to the development of infection, PICCs may be a safer alternative for prolonged inpatient IV access. The high prevalence of CLABSI-MDROs depicts the local microbial ecology, emphasizing the need of public health awareness.

Treatment duration for central line-associated infection caused by Enterococcus spp.: a retrospective evaluation of a multicenter cohort

Objective of this study was to assess the appropriate treatment duration for enterococcal central line-associated bloodstream infections (CLABSIs). This observational, retrospective, multicenter study conducted between 2011 and 2019 enrolled all hospitalized patients with monomicrobial enterococcal CLABSI. Those with infective endocarditis and non-survivors at least 7 days from index blood culture (BC) were excluded. Primary endpoint was 30-day mortality. We enrolled 113 patients, of whom 59% were male, median age was 64 (SD ± 15) and median Charlson's index score 5 (IQR 3-8). Enterococcus faecalis and Enterococcus faecium were found in 51% and 44% of cases, respectively. Median treatment duration was 11 days (IQR 6-17), and 32% of patients (n = 36) received ≤ 7 days. Characteristics of patients receiving more or less than 7 days of treatment were similar. Central line was removed in 82% (n = 93) of cases within a median of 3 days (1-8). At both uni- and multivariate analysis, duration of antibiotic treatment > 7 days was not associated with 30-day mortality [HR 0.41 (95% CI, 0.13-1.24), p = 0.12] even after adjustment with propensity score [HR 0.47 (95% CI 0.17-1.26), p = 0.13]. A 7-day treatment course appears to be safe in non-complicated enterococcal CLABSIs.

Peripherally inserted central venous catheters decrease central line-associated bloodstream infections and change microbiological epidemiology in adult hematology unit: a propensity score-adjusted analysis

Peripherally inserted central venous catheters (PICCs) have a potential advantage in preventing central line-associated bloodstream infection (CLABSI) compared with the centrally inserted ones (CICCs). However, due to a limited number of studies with insufficient statistical evaluation, the superiority of PICCs is difficult to be generalized in adult hematology unit. We conducted a single-center retrospective study and compared the risk of CLABSI between 472 CICCs and 557 PICCs inserted in adult patients with hematological disorders through conventional multivariate models and a propensity score-adjusted analysis. The overall CLABSI incidence in CICCs and PICCs was 5.11 and 3.29 per 1000 catheter days (P = 0.024). The multivariate Cox regression analysis (hazard ratio [HR]: 0.48; 95% confidence interval [CI]: 0.31-0.75; P = 0.001) and Fine-Gray subdistribution analysis (HR: 0.59; 95% CI: 0.37-0.93; P = 0.023) demonstrated that PICC was independently associated with a reduced risk of CLABSI. Moreover, the stabilized inverse probability of treatment weighting analysis, which further reduced the selection bias between CICCs and PICCs, showed that PICCs significantly prevented CLABSI (HR: 0.58; 95% CI: 0.35-0.94; P = 0.029). Microbiologically, PICCs showed a significant decrease in gram-positive cocci (P = 0.001) and an increase in gram-positive bacilli (P = 0.002) because of a remarkable reduction in Staphylococci and increase in Corynebacterium species responsible for CLABSI. Our study confirmed that PICC was a superior alternative to CICC in preventing CLABSI in the adult hematology unit, while it posed a microbiological shift in local epidemiology.

Changing epidemiology of catheter-related bloodstream infections in neutropenic oncohematological patients

Background

We aimed to describe the epidemiology of catheter-related bloodstream infections (CRBSIs) in onco-hematological neutropenic patients during a 25-year study period, to evaluate the risk factors for Gram-negative bacilli (GNB) CRBSI, as well as rates of inappropriate empirical antibiotic treatments (IEAT) and mortality.

Materials/Methods

All consecutive episodes of CRBSIs were prospectively collected (1994–2018). Changing epidemiology was evaluated comparing five-year time spans. A multivariate regression model was built to evaluate risk factors for GNB CRBSIs.

Results

482 monomicrobial CRBSIs were documented. The proportion of CRBSIs among all BSIs decreased over time from 41.2% to 15.8% (p<0.001). CRBSIs epidemiology has been changing: the rate of GNB increased over time (from 11.9% to 29.4%; p<0.001), as well as the absolute number and rate of multidrug-resistant (MDR) GNB (from 9.5% to 40.0%; p = 0.039). P. aeruginosa increased and comprised up to 40% of all GNB. Independent factors related with GNB-CRBSIs were: longer duration of in-situ catheter (OR 1.007; 95%CI 1.004–1.011), older age (OR 1.016; 95%CI 1.001–1.033), prior antibiotic treatment with penicillins (OR 2.716; 95%CI 1.306–5.403), and current antibiotic treatment with glycopeptides (OR 1.931; 95%CI 1.001–3.306). IEATs were administered to 30.7% of patients, with the highest percentage among MDR P. aeruginosa (76.9%) and S. maltophillia (92.9%). Mortality rate was greater among GNB than GPC-CRBSI (14.4% vs 5.4%; p = 0.002), with mortality increasing over time (from 4.5% to 11.2%; p = 0.003).

Conclusion

A significant shift towards GNB-CRBSIs was observed. Secondarily, and coinciding with an increasing number of GNB-MDR infections, mortality increased over time.

Microbial epidemiology and risk factors for relapse in gram-negative bacteria catheter-related bloodstream infection with a pilot prospective study in patients with catheter removal receiving short-duration of antibiotic therapy

Background

Infectious Diseases Society of America (IDSA) guidelines suggest 7–14 days’ duration of antibiotic treatment for uncomplicated Gram-negative bacteria (GNB) catheter-related bloodstream infection (CRBSI). The objectives of this study were to review microbial epidemiology, to determine rate and risk factors for relapse, and to compare clinical outcomes in patients receiving long- versus short-duration antibiotic therapy.

Methods

A retrospective phase 1 study was conducted between January 2010 and October 2016 to review microbial epidemiology and to determine the incidence of and risk factors for relapse in patients with GNB CRBSI, according to the IDSA guidelines diagnostic criteria. In phase 2 of the study, patients without risk factors for relapse between November 2016 and October 2017 were prospectively recruited to receive antibiotic therapy for 7 days after catheter removal. Matched patients from the retrospective phase 1 study who had received antibiotic therapy for ≥14 days were selected as a phase 2 control group to compare outcomes.

Results

In phase 1, three most common pathogens identified among 174 cases were Pseudomonas aeruginosa (22.0%), Klebsiella pneumoniae (16.7%), and Stenotrophomonas maltophilia (13.4%). Eighty-nine episodes of infection occurred while patients were receiving antibiotic therapy. Of 140 cases, the relapse rate was 6.4%. Catheter retention was the only risk factor strongly associated with relapse (odds ratio = 145.32; 95% confidence interval 12.66–1667.37, P < 0.001). In phase 2, 11 patients with catheter removal were prospectively recruited to receive short-duration therapy. The number of patients with relapse receiving long- or short-duration therapy was 1 (3%) and 0 (0%), respectively (P = 1.000).

Conclusions

For the management of patients with uncomplicated GNB CRBSI, empiric broad-spectrum antibiotic therapy with adequate coverage of P. aeruginosa should be chosen. Catheter removal should be performed to prevent relapse and shortening the duration of treatment could be considered.

Trial registration

Thai Clinical Trial Registry: TCTR20190914001. Retrospectively registered on 13 September 2019.

The Profile of Microorganisms Responsible for Port-Related Bacteremia in Pediatric Hemato-Oncological Patients

Patients with pediatric cancer face an increased risk of infections. In most cases, these infections are associated with the use of a long-term central venous catheter. This study describes the epidemiology of a port-associated bacteremia as well as a profile of microorganisms responsible for port-associated bloodstream infections (PABSIs) in pediatric patients with cancer treated in a single center. The retrospective analysis included patients with cancer who had implanted a port, hospitalized between 2010 and 2015 at the Department of Pediatric Oncology, Hematology and Bone Marrow Transplantation, Poznan University of Medical Sciences. The medical records of patients were reviewed for demographic characteristics, diagnosis, port-related complications, and their management. Data were collected from patients' electronic medical records containing complete information on medical examinations and supplementary tests, diagnosis, timing, and type of port-associated complications. In a study period, 277 ports were inserted to 241 patients. A total of 183 094 catheter days were analyzed. Sixteen patients had more than 1 insertion of a port. The commonest observed complication was PABSI (40.07%) and the incidence density was 0.6 per 1000 port-days. Staphylococcus was the most commonly isolated organisms from patients with PABSI. From all port-associated complications, bloodstream infections and mechanical complications were the most often observed complications. The commonest pathogens responsible for PABSI were coagulase-negative staphylococci. Pathogens resistant to standard antibiotic treatment play an important role in PABSI, with methicillin-resistant Staphylococcus epidermidis being the predominant pathogen. Port-associated bloodstream infections are a common reason for preterm removal of a port.

Practice Guidelines for Central Venous Access 2020

These practice guidelines update the Practice Guidelines for Central Venous Access: A Report by the American Society of Anesthesiologists Task Force on Central Venous Access, adopted by the American Society of Anesthesiologists in 2011 and published in 2012. These updated guidelines are intended for use by anesthesiologists and individuals under the supervision of an anesthesiologist and may also serve as a resource for other physicians, nurses, or healthcare providers who manage patients with central venous catheters.

Supplemental Digital Content is available in the text.

Is heparinized 40% ethanol lock solution efficient for reducing bacterial and fungal biofilms in an in vitro model?

Background

We applied an in vitro model to evaluate the efficacy of a heparinized 40% ethanol-based lock solution in a wide variety of clinical isolates causing C-RBSI.

Methods

A total of 100 clinical strains were collected retrospectively from the blood of patients with C-RBSI. The reduction in biomass and metabolic activity of biofilms was measured using the crystal violet (CV) assay and XTT assay, respectively. Regrowth inhibition (RI) was measured within 24 hours and 72 hours of ethanol lock therapy. Percentage reduction of ≥ 85% in RI was considered to be successful.

Results

Ethanol lock was more effective in reducing metabolic activity than in reducing biomass (83% vs. 50%, respectively). Percentages of RI diminished as regrowth was prolonged (57% for 24 hours and 17% for 72 hours of regrowth). No statistically significant intraspecies differences were found in biofilm reduction or in RI (p>0.05).

Conclusions

The use of heparinized 40% ethanol lock solution for 72 hours significantly reduced biomass and metabolic activity in clinical isolates from patients with C-RBSI. However, as biofilm has an important regrowth rate, 40% ethanol solution was not able to fully eradicate biofilm in vitro.

Catheter-related infections: does the spectrum of microbial causes change over time? A nationwide surveillance study

OBJECTIVES

To estimate the incidence and epidemiology of catheter-related bloodstream infections (CRBSIs) on a national scale by using prospective epidemiological data from the Swiss Antibiotic Resistance Surveillance System (ANRESIS).

DESIGN

Observational study.

SETTING

National surveillance from 2008 to 2015 of acute hospitals in Switzerland.

PARTICIPANTS

We included acute Swiss hospitals that sent blood cultures and catheter tip culture results on a regular basis during the entire study period to the ANRESIS database.

OUTCOME MEASURE

A catheter-related bloodstream infection (termed 'modified CRBSI', mCRBSI) was defined as isolating the same microorganism with identical antibiogram from ≥1 blood cultures (performed ±7 days around the catheter removal) as the one recovered from the catheter tip. Incidence rates of mCRBSI were calculated per 1000 admissions.

RESULTS

From 2008 to 2015, the mCRBSI incidence rate decreased from 0.83 to 0.58 episodes/1000 admissions (-6% per year, p<0.001). Coagulase-negative staphylococci, Staphylococcus aureus and fungi all exhibited decreasing trends, while rates of enterococci and Gram-negative bacteria remained stable.

CONCLUSIONS

The overall incidence of mCRBSI in Switzerland is decreasing; however, the incidence of mCRBSI due to Enterococci and Gram-negative micro-organisms did not change over time. These pathogens may grow in importance in catheter-related infections, which would have clinical implications for the choice of empirical treatment.

Short-Term Peripheral Venous Catheter-Related Bloodstream Infections: Evidence for Increasing Prevalence of Gram-Negative Microorganisms from a 25-Year Prospective Observational Study

The aim of this study was to describe the etiology and outcome of short-term peripheral venous catheter (PVC)-related bloodstream infections (PVCRBSI) in a 25-year period (1992 to 2016) and to identify predictive factors of Gram-negative PVCRBSI. This was a prospective observational study including all episodes of PVCRBSI. A multivariate logistic regression model adjusted for calendar year was built to explore factors associated with a Gram-negative bacterial etiology. Over the study period, 711 episodes of PVCRBSI were identified. Incidence rate of PVCRBSI increased from 0.06 to 0.13 episodes/1,000 patient-days. A Gram-negative bacterial etiology was demonstrated in 162 (22.8%) episodes. There was a significant increase in the proportion of Gram-negative infections (22.6% in 1992 to 1996 versus 33.2% in 2012 to 2016). Independent predictive factors of Gram-negative PVCRBSI were the following: being in the hospital for more than 7 days with a catheter in situ for more than 3 days (adjusted odds ratio [aOR], 1.80; 95% confidence interval [CI], 1.20 to 2.69), surgery in the previous month (aOR, 2.39; 95% CI, 1.40 to 4.09), and antimicrobial treatment with beta-lactams (aOR, 1.80; 95% CI, 1.16 to 2.78). In conclusion, we reported an increase in the prevalence of Gram-negative PVCRBSI over the last 25 years. Factors associated with a Gram-negative bacterial etiology were being in the hospital for more than 7 days with a catheter in situ for more than 3 days, having undergone surgery, and having received antimicrobial treatment with beta-lactams.

Trends of Bloodstream Infections in a University Greek Hospital during a Three-Year Period: Incidence of Multidrug-Resistant Bacteria and Seasonality in Gram-negative Predominance

The aim of the study was to assess the epidemiology, the incidence of multidrug-resistant bacteria and bloodstream infections' (BSIs) seasonality in a university hospital. This retrospective study was carried out in the University General Hospital of Patras, Greece, during 2011-13 y. Blood cultures from patients with clinical presentation suggestive of bloodstream infection were performed by the BacT/ALERT System. Isolates were identified by Vitek 2 Advanced Expert System. Antibiotic susceptibility testing was performed by the disk diffusion method and E-test. Resistance genes (mecA in staphylococci; vanA/vanB/vanC in enterococci; bla_KPC/bla_VIM/bla_NDM in Klebsiella spp.) were detected by PCR. In total, 4607 (9.7%) blood cultures were positive from 47451 sets sent to Department of Microbiology, representing 1732 BSIs. Gram-negative bacteria (52.3%) were the most commonly isolated, followed by Gram-positive (39.5%), fungi (6.6%) and anaerobes bacteria (1.8%). The highest contamination rate was observed among Gram-positive bacteria (42.3%). Among 330 CNS and 150 Staphylococcus aureus, 281 (85.2%) and 60 (40.0%) were mecA-positive, respectively. From 113 enterococci, eight were vanA, two vanB and two vanC-positives. Of the total 207 carbapenem-resistant Klebsiella pneumoniae (73.4%), 202 carried bla_KPC, four bla_KPC and bla_VIM and one bla_VIM. A significant increase in monthly BSIs' incidence was shown (R2: 0.449), which may be attributed to a rise of Gram-positive BSIs (R2: 0.337). Gram-positive BSIs were less frequent in spring (P < 0.001), summer (P < 0.001), and autumn (P < 0.001), as compared to winter months, while Gram-negative bacteria (P < 0.001) and fungi (P < 0.001) were more frequent in summer months. BSIs due to methicillin resistant S. aureus and carbapenem-resistant Gram-negative bacteria increased during the study period. The increasing incidence of BSIs can be attributed to an increase of Gram-positive BSI incidence, even though Gram-negative bacteria remained the predominant ones. Seasonality may play a role in the predominance of Gram-negative's BSI.

Clinical impact of delayed catheter removal for patients with central-venous-catheter-related Gram-negative bacteraemia

BACKGROUND

Gram-negative bacteria are increasingly the cause of catheter-related bloodstream infection (CRBSI), and the prevalence of multi-drug-resistant strains is rising rapidly. This study evaluated the impact of delayed central venous catheter (CVC) removal on clinical outcomes in patients with Gram-negative CRBSI.

METHODS

Between January 2007 and December 2016, patients with Gram-negative bacteraemia and CVC placement, from two tertiary care hospitals, were included retrospectively. Cases with CVC removal more than three days after onset of bacteraemia or without CVC removal were classified as having delayed CVC removal.

RESULTS

In total, 112 patients were included. Of these, 78 had CRBSI (43 definite and 35 probable) and 34 had Gram-negative bacteraemia from another source (non-CRBSI). Enterobacteriaceae were less common pathogens in patients with CRBSI than in patients with non-CRBSI (11.5% vs 41.3%; P<0.001). Delayed CVC removal was associated with increased 30-day mortality (40.5% vs 11.8%; P=0.01) in patients with Gram-negative CRBSI; this was not seen in patients with non-CRBSI (25.0% vs 14.3%; P>0.99). Delayed CVC removal [odds ratio (OR) 6.8], multi-drug-resistant (MDR) Gram-negative bacteraemia (OR 6.3) and chronic renal failure (OR 11.1) were associated with 30-day mortality in patients with CRBSI. The protective effect of early CVC removal on mortality was evident in the MDR group (48.3% vs 18.2%; P=0.03), but not in the non-MDR group (11.1% vs 0%; P=0.43).

CONCLUSION

CVCs should be removed early to improve clinical outcomes in patients with Gram-negative CRBSI, especially in settings where MDR isolates are prevalent.

The epidemiology, antibiograms and predictors of mortality among critically-ill patients with central line-associated bloodstream infections

BACKGROUND/PURPOSE

For high risk of central line-associated bloodstream infections (CLABSIs) in patients of intensive care units (ICUs) and scarcely epidemiology and therapeutic recommendations in Asia, we aimed to evaluate the annual change in epidemiology, antibiogram, and risk factors for 14-day mortality.

METHODS

A retrospective study of ICUs patients with CLABSIs at a medical center in Taiwan (2010-2016), where central line care bundle implemented since 2014, by reviewing clinical data, pathogens, and the antibiogram.

RESULTS

Gram-negative bacteria (59.3%) were main microorganisms of CLABSIs, and 9.0% of all GNB were MDROs. Acinetobacter spp., Enterobacter spp., and Stenotrophomonas maltophilia were the most frequently isolated. In multivariate analysis, malignancy, inadequate empirical antimicrobial therapy, inadequate definite antimicrobial therapy, and infection by fungi or multidrug-resistant organisms (MDROs) were associated with 14-day mortality (all p < 0.05). The CLABSI incidence rate decreased from 5.54 to 2.18 per 1000 catheter-day (from 2014 to 2015) with improved compliance to care bundle. Carbapenem and aminoglycoside were suitable empirical drugs in the hospital setting when GNB is predominant for CLABSI. Significant decreasing susceptibility of ampicillin/sulbactam in Enterobacter spp. (36.7%-0.0%), and ampicillin/sulbactam (12.5%-0.0%), ceftazidime (100.0%-52.9%), and tigecycline (87.5%-35.3%) in Serratia marcescens.

CONCLUSION

We identified Gram-negative bacteria as leading pathogens of CLABSIs in a Taiwan medical center, and good compliance to care bundle is associated with reduced CLABSI incidence rate. Malignancy, infection by MDROs or fungi, inadequate empirical or definite antimicrobial therapy are significant factors for 14-day mortality.

A Real-Time PCR Assay Based on 5.8S rRNA Gene (5.8S rDNA) for Rapid Detection of Candida from Whole Blood Samples

The prevalence of Candida in bloodstream infections (BSIs) has increased. To date, the identification of Candida in BSIs still mainly relies on blood culture and serological tests, but they have various limitations. Therefore, a real-time PCR assay for the detection of Candida from whole blood is presented. The unique primers/probe system was designed on 5.8S rRNA gene (5.8S rDNA) of Candida genus. The analytical sensitivity was determined by numbers of positive PCRs in 12 repetitions. At the concentration of 10(1) CFU/ml blood, positive PCR rates of 100 % were obtained for C. albicans, C. parapsilosis, C. tropicalis, and C. krusei. The detection rate for C. glabrata was 75 % at 10(1) CFU/ml blood. The reaction specificity was 100 % when evaluating the assay using DNA samples from clinical isolates and human blood. The maximum CVs of intra-assay and inter-assay for the detection limit were 1.22 and 2.22 %, respectively. To assess the clinical applicability, 328 blood samples from 82 patients were prospectively tested and real-time PCR results were compared with results from blood culture. Diagnostic sensitivity of the PCR was 100 % using as gold standard blood culture, and specificity was 98.4 %. Our data suggest that the developed assay can be used in clinical laboratories as an accurate and rapid screening test for the Candida from whole blood. Although further evaluation is warranted, our assay holds promise for earlier diagnosis of candidemia.

Central line-associated bloodstream infections among critically-ill patients in the era of bundle care

BACKGROUND/PURPOSE

Patients admitted to intensive care units (ICUs) are at high risk for central line-associated bloodstream infections (CLABSIs). Bundle care has been documented to reduce CLABSI rates in Western countries, however, few reports were from Asian countries and the differences in the epidemiology or outcomes of critically-ill patients with CLABSIs after implementation of bundle care remain unknown. We aimed to evaluate the incidence, microbiological characteristics, and factors associated with mortality in critically-ill patients after implementation of bundle care.

METHODS

Prospective surveillance was performed on patients admitted to ICUs at the National Taiwan University Hospital, Taipei, Taiwan from January 2012 to June 2013. The demographic, microbiological, and clinical data of patients who developed CLABSI according to the National Healthcare Safety Network definition were reviewed. A total of 181 episodes of CLABSI were assessed in 156 patients over 46,020 central-catheter days.

RESULTS

The incidence of CLABSI was 3.93 per 1000 central-catheter days. The predominant causative microorganisms isolated from CLABSI episodes were Gram-negative bacteria (39.2%), followed by Gram-positive bacteria (33.2%) and Candida spp. (27.6%). Median time from insertion of a central catheter to occurrence of CLABSI was 8 days. In multivariate analysis, the independent factors associated with mortality were higher Pitt bacteremia score [odds ratio (OR) 1.41; 95% confidence interval (CI) 1.18-1.68] and longer interval between onset of CLABSIs and catheter removal (OR 1.10; 95% CI 1.02-1.20), respectively.

CONCLUSION

In institutions with a high proportion of CLABSI caused by Gram-negative bacteria, severity of bacteremia and delay in catheter removal were significant factors associated with mortality.

Improving compliance with central venous catheter care bundles using electronic records

BACKGROUND

Health care associated infections are a major contributor to avoidable harm experienced by patients in modern health care settings. Recent reports suggest that electronic checklists for the documentation of a central line bundle may significantly enhance documented process compliance and help to reduce catheter-related bloodstream infection rates.

AIMS

This paper describes the use of our electronic tool to monitor and feedback process compliance in conjunction of introducing bespoke central line insertion packs to tackle catheter-related bloodstream infections in our intensive care unit in a medium-sized district general hospital.

DESIGN AND METHODS

Continuous quality improvement programme with 'Plan-Do-Study-Act' cycles was implemented. The central venous catheter insertion and maintenance bundle was rolled out in 2007. To monitor compliance with the bundle elements, an electronic tool was designed as part of our bedside Clinical Information System. From 2009, regular quarterly feedback was provided on the number of central venous catheter lines inserted, compliance with the insertion and maintenance bundle and catheter-related bloodstream infection rate using the data collected through the Clinical Information System. We have also introduced dedicated line insertion trolleys and factory-prepared insertion packs. We used segmented regression analysis to assess the changes in the catheter-related bloodstream infection rate before and after implementation of the central venous catheter bundle.

RESULTS

Bundle compliance increased during the implementation period and reached over 95% within 6 months. We observed a significant reduction in the catheter-related bloodstream infection rate from 15.6/1000 days to 0.4/1000 days. Regression analysis showed that only the compliance had significant effect on the number and prevalence of catheter-related bloodstream infections.

CONCLUSION/IMPLICATIONS

Implementation of evidence-based care bundles reinforced by real-time feedback on the performance of caregivers can significantly reduce the rate of catheter-related bloodstream infection in the intensive care unit. Ensuring that change processes are seamlessly integrated in the workflow with minimal administrative burden is crucial to the quality improvement process.

Magnitude of enterococcal bacteremia in trauma patients admitted for intensive trauma care: a tertiary care experience from South asian country

Background:

Bloodstream infection (BSI) and bacteremias due to Enterococcus spp. are increasing worldwide with the current need to understand its causes among hospitalized trauma patients. Hence, the study was conducted.

Methodology:

A 3-year retrospective laboratory cum clinical based study was performed at a level I trauma center in India. Patients with health care associated enterococcal bacteremia were identified using the hospital database, their episodes of BSI/bacteremia calculated and their clinical records and treatment were noted.

Results:

A total of 104 nonrepetitive Enterococcus spp. was isolated of which Enterococcus faecium was the most common (52%). High-level resistance to gentamicin high-level aminoglycoside resistance was seen in all the Enterococcus spp. causing bacteremia, whereas a low resistance to vancomycin and teichoplanin was observed. Overall mortality was more in patients infected with vancomycin-resistant Enterococcus (5/11, 46%) compared to those with vancomycin sensitive Enterococcus (9/93, 10%); though no significant association of mortality with Enterococcus spp. bacteremia (P > 0.05) was seen. The rate of bacteremia due to Enterococcus spp. was 25.4 episodes/1,000 admissions (104/4,094) during the study period.

Conclusion:

Enterococcal bacteremia is much prevalent in trauma care facilities. Here, a microbiologist can act as a sentinel and help in preventing such infections.

Surveillance of catheter-related infections: the supplementary role of the microbiology laboratory

BACKGROUND

The burden of catheter-related infections (CRIs) in developing countries is severe. In South Africa, a standardised surveillance definition does not exist and the collection of catheter days is challenging. The aim of the study was to provide baseline data on the prevalence of CRIs and to describe the epidemiology of CRI events within a tertiary academic hospital.

METHODS

Surveillance was laboratory-based and conducted for a six month period. A microbiologically confirmed CRBSI (MC-CRBSI) event was defined as the isolation of the same microorganism from the catheter and concomitant blood cultures (BCs), within 48 h of catheter removal, which were not related to an infection at another site.

RESULTS

A total of 508 catheters, removed from 332 patients, were processed by the laboratory, of which only 50% (253/508 removed from 143/332 patients) of the catheters were accompanied by BCs within 48 h. Sixty-five episodes of MC-CRBSI in 57 patients were detected, involving 71 catheters and 195 microbial isolates. The institutional prevalence rate was 3.7 episodes per 1 000 admissions and 5.8 episodes per 10 000 in-patient days. Catheter day data was collected in only six wards of the hospital. The pooled laboratory incidence was 10.1 MC-CRBSI episodes per 1 000 catheter days, whereas the hospital-based central line-associated bloodstream infection (CLABSI) rate was pooled at 5.7 episodes per 1 000 catheter days. The majority of patients had an underlying gastro-intestinal condition (33%; 19/56) with a non-tunnelled, triple-lumen central venous catheter, placed in the subclavian vein (38%; 27/71). The most predominant pathogen was methicillin-resistant Staphylococcus epidermidis (28%; 55/195), followed by extensively-drug resistant Acinetobacter baumannii (18%; 35/195).

CONCLUSIONS

Catheter-related infection prevention and control efforts require urgent attention, not only to keep patients safe from preventable harm, but to prevent the spread of multidrug resistant microorganisms.

Micafungin at physiological serum concentrations shows antifungal activity against Candida albicans and Candida parapsilosis biofilms

We assessed the in vitro activity of micafungin against preformed Candida biofilms by measuring the concentration of drug causing the most fungal damage and inhibition of regrowth. We studied 37 biofilm-producing Candida spp. strains from blood cultures. We showed that micafungin was active against planktonic and sessile forms of Candida albicans strains and moderately active against Candida parapsilosis sessile cells. Concentrations of micafungin above 2 μg/ml were sufficiently high to inactivate regrowth of Candida sessile cells.

Ethanol lock therapy (E-Lock) in the prevention of catheter-related bloodstream infections (CR-BSI) after major heart surgery (MHS): a randomized clinical trial

BACKGROUND

Lock-therapy with antimicrobials has been used for the treatment and prevention of catheter-related bloodstream infections (CR-BSI). Experiences with Ethanol-Locks (E-locks) have included therapeutic interventions with variable results. Patients undergoing Major Heart Surgery (MHS) are a high-risk population for CR-BSI.The aim of this study was to assess the efficacy and tolerance to E-Locks in the prevention of CR-BSI of patients undergoing MHS.

METHODS AND FINDINGS

This is an academic, prospective, randomized, non-blinded and controlled clinical trial assessing the incidence of CR-BSI of patients with E-locks (E-lock) and the tolerance to the procedure in comparison with patients receiving conventional catheter-care (CCC). Patients undergoing MHS with intravascular catheters for more than 48 hours were randomly assigned into treatment or control group by a computer-generated list of randomly assigned numbers. In the treatment group, all their catheter lumens were locked with an ethanol solution at 70% for two hours, every three days (E-Locks). The control group received conventional catheter-care (CCC). Overall, 200 patients with 323 catheters were included in the study, which was stopped after 10 months due to adverse events. Of them, 179 catheters (113 patients) had E-Locks and 144 catheters (87 patients) were CCC. Euroscore Surgical Risk in both groups was 4.04 vs 4.07 p = 0.94 respectively. The results for the E-Locks and CCC were as follows: Incidence of CR-BSI/1000 days of exposure 2.1 vs 5.2 (p = 0.33), catheter tip colonization 14 (7.8%) vs 6 (4.2%) patients (p = 0.17), median length of hospital stay, 15 vs 16 days (p = 0.77). Seven patients (6.19%), all in the ethanol branch, had to discontinue the trial due to intolerance or adverse events.

CONCLUSIONS

We do not recommend prophylaxis of CR-BSI with ethanol-lock on a routine basis in patients undergoing Major Heart Surgery.

TRIAL REGISTRATION

Clinical Trials.gov NCT01229592.

Bugs, hosts and ICU environment: countering pan-resistance in nosocomial microbiota and treating bacterial infections in the critical care setting

ICUs are areas where resistance problems are the largest, and these constitute a major problem for the intensivist's clinical practice. Main resistance phenotypes among nosocomial microbiota are (i) vancomycin-resistance/heteroresistance and tolerance in grampositives (MRSA, enterococci) and (ii) efflux pumps/enzymatic resistance mechanisms (ESBLs, AmpC, metallo-betalactamases) in gramnegatives. These phenotypes are found at different rates in pathogens causing respiratory (nosocomial pneumonia/ventilator-associated pneumonia), bloodstream (primary bacteremia/catheter-associated bacteremia), urinary, intraabdominal and surgical wound infections and endocarditis in the ICU. New antibiotics are available to overcome non-susceptibility in grampositives; however, accumulation of resistance traits in gramnegatives has led to multidrug resistance, a worrisome problem nowadays. This article reviews microorganism/infection risk factors for multidrug resistance, suggesting adequate empirical treatments. Drugs, patient and environmental factors all play a role in the decision to prescribe/recommend antibiotic regimens in the specific ICU patient, implying that intensivists should be familiar with available drugs, environmental epidemiology and patient factors.

Catheter-related bloodstream infections caused by Gram-negative bacteria

From 2008 to 2010, patients with microbiologically confirmed Gram-negative catheter-related bloodstream infection (GN-CRBSI) were each compared with two randomly selected controls. We included 81 cases (17% of all CRBSI) and 162 controls with CRBSI caused by other pathogens. Incidence of GN-CRBSI was 0.53 episodes per 1000 admissions. Cases were more likely to have underlying neurological disease or gastrointestinal conditions, previous antimicrobial therapy and a shorter time to blood culture positivity. Surgery in the present admission (odds ratio: 3.5), P. aeruginosa (3.6) and a complicated bacteraemia (4.1) were related to a higher mortality rate. GN-CRBSI accounts for 17% of all CRBSI and should be taken into consideration in the empirical therapy of patients with the characteristics mentioned above.