Clinical sub-phenotypes of Staphylococcus aureus bacteraemia.

BACKGROUND: Staphylococcus aureus bacteraemia (SAB) is a clinically heterogeneous disease. The ability to identify sub-groups of patients with shared traits (sub-phenotypes) is an unmet need that could allow patient stratification for clinical management and research. We aimed to test the hypothesis that clinically-relevant sub-phenotypes can be reproducibly identified amongst patients with SAB. METHODS: We studied three cohorts of hospitalised adults with monomicrobial SAB: a UK retrospective observational study (Edinburgh cohort, n=458), the UK ARREST randomised trial (n=758), and the Spanish SAFO randomised trial (n=214). Latent class analysis was used to identify sub-phenotypes using routinely-collected clinical data, without considering outcomes. Mortality and microbiologic outcomes were then compared between sub-phenotypes. RESULTS: Included patients had predominantly methicillin-susceptible SAB (1366/1430,95.5%). We identified five distinct, reproducible clinical sub-phenotypes: (A) SAB associated with older age and comorbidity, (B) nosocomial intravenous catheter-associated SAB in younger people without comorbidity, (C) community-acquired metastatic SAB, (D) SAB associated with chronic kidney disease, and (E) SAB associated with injection drug use. Survival and microbiologic outcomes differed between the sub-phenotypes. 84-day mortality was highest in sub-phenotype A, and lowest in B and E. Microbiologic outcomes were worse in sub-phenotype C. In a secondary analysis of the ARREST trial, adjunctive rifampicin was associated with increased 84-day mortality in sub-phenotype B and improved microbiologic outcomes in sub-phenotype C. CONCLUSIONS: We have identified reproducible and clinically-relevant sub-phenotypes within SAB, and provide proof-of-principle of differential treatment effects. Through clinical trial enrichment and patient stratification, these sub-phenotypes could contribute to a personalised medicine approach to SAB.

Effect of a bundle intervention on adherence to quality-of-care indicators and on clinical outcomes in patients with Staphylococcus aureus bacteraemia hospitalized in non-referral community hospitals.

BACKGROUND: Although a significant number of cases of Staphylococcus aureus bacteraemia (SAB) are managed at non-referral community hospitals, the impact of a bundle-of-care intervention in this setting has not yet been explored. METHODS: We performed a quasi-experimental before-after study with the implementation of a bundle of care for the management of SAB at five non-referral community hospitals and a tertiary care university hospital. Structured recommendations for the five indicators selected to assess quality of care were provided to investigators before the implementation of the bundle and monthly thereafter. Primary endpoints were adherence to the bundle intervention and treatment failure, defined as death or relapse at 90 days of follow-up. RESULTS: One hundred and seventy patients were included in the pre-intervention period and 103 in the intervention period. Patient characteristics were similar in both periods. Multivariate analysis controlling for potential confounders showed that performance of echocardiography was the only factor associated with improved adherence to the bundle in the intervention period (adjusted OR 2.13; 95% CI 1.13-4.02). Adherence to the bundle, performance of follow-up blood cultures, and adequate duration of antibiotic therapy for complicated SAB presented non-significant improvements. The intervention was not associated with a lower rate of 90 day treatment failure (OR 1.11; 95% CI 0.70-1.77). CONCLUSIONS: A bundle-of-care intervention for the management of SAB at non-referral community hospitals increased adherence to quality indicators, but did not significantly reduce rates of 90 day mortality or relapse.

Quality check: concordance between two monitoring systems for postoperative organ/space-surgical site infections in rectal cancer surgery. Linkage of data from the Catalan Cancer Plan and the VINCat infection surveillance programme.

BACKGROUND: The Catalan Cancer Plan (CCP) undertakes periodic audits of cancer treatment outcomes, including organ/space surgical site infections (O/S-SSI) rates, while the Catalan Healthcare-associated Infections Surveillance Programme (VINCat) carries out standardized prospective surveillance of surgical site infections (SSI) in colorectal surgery. This cohort study aimed to assess the concordance between these two monitoring systems for O/S-SSI following primary rectal cancer surgery. METHODS: The study compared O/S-SSI incidence data from CCP clinical audits versus the VINCat Programme in patients undergoing surgery for primary rectal cancer, in 2011-12 and 2015-16, in publicly funded centres in Spain. The main outcome variable was the incidence of O/S-SSI in the first 30 days after surgery. Concordance between the two registers was analysed using Cohen's kappa. Discordant cases were reviewed by an expert, and the main reasons for discrepancies evaluated. RESULTS: Pooling data from both databases generated a sample of 2867 patients. Of these, O/S-SSI was detected in 414 patients-235 were common to both registry systems, with satisfactory concordance (κ = 0.69, 95% confidence interval 0.65-0.73). The rate of discordance from the CCP (positive cases in VINCat and negative in CCP) was 2.7%, and from VINCat (positive in CCP and negative in VINCat) was 3.6%. External review confirmed O/S-SSI in 66.2% of the cases in the CCP registry and 52.9% in VINCat. CONCLUSIONS: This type of synergy shows the potential of pooling data from two different information sources with a satisfactory level of agreement as a means to improving O/S-SSI detection. CLINICALTRIALS: gov Identifier: NCT06104579. Registered 30 November 2023.

Effects of the COVID-19 Pandemic on Incidence and Epidemiology of Catheter-Related Bacteremia, Spain.

We compared hospital-acquired catheter-related bacteremia (CRB) episodes diagnosed at acute care hospitals in Catalonia, Spain, during the COVID-19 pandemic in 2020 with those detected during 2007-2019. We compared the annual observed and predicted CRB rates by using the negative binomial regression model and calculated stratified annual root mean squared errors. A total of 10,030 episodes were diagnosed during 2007-2020. During 2020, the observed CRB incidence rate was 0.29/103 patient-days, whereas the predicted CRB rate was 0.14/103 patient-days. The root mean squared error was 0.153. Thus, a substantial increase in hospital-acquired CRB cases was observed during the COVID-19 pandemic in 2020 compared with the rate predicted from 2007-2019. The incidence rate was expected to increase by 1.07 (95% CI 1-1.15) for every 1,000 COVID-19-related hospital admissions. We recommend maintaining all CRB prevention efforts regardless of the coexistence of other challenges, such as the COVID-19 pandemic.

Trends in the epidemiology of catheter-related bloodstream infections; towards a paradigm shift, Spain, 2007 to 2019.

BackgroundCatheter-related bloodstream infections (CRBSI) are frequent healthcare-associated infections and an important cause of death.AimTo analyse changes in CRBSI epidemiology observed by the Infection Control Catalan Programme (VINCat).MethodsA cohort study including all hospital-acquired CRBSI episodes diagnosed at 55 hospitals (2007-2019) in Catalonia, Spain, was prospectively conducted. CRBSI incidence rates were adjusted per 1,000 patient days. To assess the CRBSI rate trend per year, negative binomial models were used, with the number of events as the dependent variable, and the year as the main independent variable. From each model, the annual rate of CRBSI diagnosed per 1,000 patient days and the incidence rate ratio (IRR) with its 95% confidence intervals (CI) were reported.ResultsDuring the study, 9,290 CRBSI episodes were diagnosed (mean annual incidence rate: 0.20 episodes/1,000 patient days). Patients' median age was 64.1 years; 36.6% (3,403/9,290) were female. In total, 73.7% (n = 6,845) of CRBSI occurred in non-intensive care unit (ICU) wards, 62.7% (n = 5,822) were related to central venous catheter (CVC), 24.1% (n = 2,236) to peripheral venous catheters (PVC) and 13.3% (n = 1,232) to peripherally-inserted central venous catheters (PICVC). Incidence rate fell over the study period (IRR: 0.94; 95%CI: 0.93-0.96), especially in the ICU (IRR: 0.88; 95%CI: 0.87-0.89). As a whole, while episodes of CVC CRBSI fell significantly (IRR: 0.88; 95%CI: 0.87-0.91), peripherally-inserted catheter CRBSI (PVC and PICVC) rose, especially in medical wards (IRR PICVC: 1.08; 95%CI: 1.05-1.11; IRR PVC: 1.03; 95% 1.00-1.05).ConclusionsOver the study, CRBSIs associated with CVC and diagnosed in ICUs decreased while episodes in conventional wards involving peripherally-inserted catheters increased. Hospitals should implement preventive measures in conventional wards.

A Care Bundle Intervention to Prevent Surgical Site Infections After a Craniotomy.

BACKGROUND: Although surgical site infections after a craniotomy (SSI-CRANs) are a serious problem that involves significant morbidity and costs, information on their prevention is scarce. We aimed to determine whether the implementation of a care bundle was effective in preventing SSI-CRANs. METHODS: A historical control study was used to evaluate the care bundle, which included a preoperative shower with 4% chlorhexidine soap, appropriate hair removal, adequate preoperative systemic antibiotic prophylaxis, the administration of 1 g of vancomycin powder into the subgaleal space before closing, and a postoperative dressing of the incisional surgical wound with a sterile absorbent cover. Patients were divided into 2 groups: preintervention (January 2013 to December 2015) and intervention (January 2016 to December 2017). The primary study end point was the incidence of SSI-CRANs within 1 year postsurgery. Propensity score matching was performed, and differences between the 2 study periods were assessed using Cox regression models. RESULTS: A total of 595 and 422 patients were included in the preintervention and intervention periods, respectively. The incidence of SSI-CRANs was lower in the intervention period (15.3% vs 3.5%; P < .001). Using a propensity score model, 421 pairs of patients were matched. The care bundle intervention was independently associated with a reduced incidence of SSI-CRANs (adjusted odds ratio, 0.23; 95% confidence interval, .13-.40; P < .001). CONCLUSIONS: The care bundle intervention was effective in reducing SSI-CRAN rates. The implementation of this multimodal preventive strategy should be considered in centers with high SSI-CRAN incidences.

Daptomycin Plus Fosfomycin Versus Daptomycin Alone for Methicillin-resistant Staphylococcus aureus Bacteremia and Endocarditis: A Randomized Clinical Trial.

BACKGROUND: We aimed to determine whether daptomycin plus fosfomycin provides higher treatment success than daptomycin alone for methicillin-resistant Staphylococcus aureus (MRSA) bacteremia and endocarditis. METHODS: A randomized (1:1) phase 3 superiority, open-label, and parallel group clinical trial of adult inpatients with MRSA bacteremia was conducted at 18 Spanish hospitals. Patients were randomly assigned to receive either 10 mg/kg of daptomycin intravenously daily plus 2 g of fosfomycin intravenously every 6 hours, or 10 mg/kg of daptomycin intravenously daily. Primary endpoint was treatment success 6 weeks after the end of therapy. RESULTS: Of 167 patients randomized, 155 completed the trial and were assessed for the primary endpoint. Treatment success at 6 weeks after the end of therapy was achieved in 40 of 74 patients who received daptomycin plus fosfomycin and in 34 of 81 patients who were given daptomycin alone (54.1% vs 42.0%; relative risk, 1.29 [95% confidence interval, .93-1.8]; P = .135). At 6 weeks, daptomycin plus fosfomycin was associated with lower microbiologic failure (0 vs 9 patients; P = .003) and lower complicated bacteremia (16.2% vs 32.1%; P = .022). Adverse events leading to treatment discontinuation occurred in 13 of 74 patients (17.6%) receiving daptomycin plus fosfomycin, and in 4 of 81 patients (4.9%) receiving daptomycin alone (P = .018). CONCLUSIONS: Daptomycin plus fosfomycin provided 12% higher rate of treatment success than daptomycin alone, but this difference did not reach statistical significance. This antibiotic combination prevented microbiological failure and complicated bacteremia, but it was more often associated with adverse events. CLINICAL TRIALS REGISTRATION: NCT01898338.

Risk factors for enterococcal urinary tract infections: a multinational, retrospective cohort study.

Complicated urinary tract infection (cUTI) is a frequent cause of morbidity. In this multinational retrospective cohort study, we aimed to demonstrate risk factors for enterococcal UTI. Univariate and multivariate analyses of risk factors for enterococcal infection were performed. Among 791 hospitalized patients with cUTI, enterococci accounted for approximately 10% of cases (78/791). Risk factors for enterococcal UTI in multivariable analysis were male gender, age range of 55-75 years, catheter-associated UTI, and urinary retention. This information may assist treating physicians in their decision-making on prescribing empiric anti-enterococcus treatment to hospitalized patients presenting with cUTI and thus improve clinical outcomes.

Impact of ß-Lactam and Daptomycin Combination Therapy on Clinical Outcomes in Methicillin-susceptible Staphylococcus aureus Bacteremia: A Propensity Score-matched Analysis.

BACKGROUND: Mortality rates from Staphylococcus aureus bacteremia are high and have only modestly improved in recent decades. We compared the efficacies of a ß-lactam in combination with daptomycin (BL/D-C) and ß-lactam monotherapy (BL-M) in improving clinical outcomes in methicillin-susceptible S. aureus (MSSA) bacteremia. METHODS: A retrospective cohort study of MSSA bacteremia was performed in a tertiary hospital from January 2011 to December 2017. Patients receiving BL/D-C and BL-M were compared to assess 7-, 30-, and 90-day mortality rates. A 1:2 propensity score matching analysis was performed. Differences were assessed using Cox regression models. RESULTS: Of the 514 patients with MSSA bacteremia, 164 were excluded as they had received combination therapies other than BL/D-C, had pneumonia, or died within 48 hours of admission. Of the remaining 350 patients, 136 and 214 received BL/D-C and BL-M, respectively. BL/D-C patients had higher Pitt scores and persistent bacteremia more often than BL-M patients. In the raw analysis, there were no differences in mortality rates between groups. After propensity score matching, there were no significant differences between the BL/D-C (110 patients) and BL-M (168 patients) groups for all-cause mortality rates at 7 days (8.18% vs 7.74%; P = 1.000), 30 days (17.3% vs 16.1%; P = .922), and 90 days (22.7% vs 23.2%; P = 1.000), even in a subanalysis of patients with high-risk source of infection and in a subgroup excluding catheter-related bacteremia. CONCLUSIONS: BL/D-C failed to reduce mortality rates in patients with MSSA bacteremia. Treatment strategies to improve survival in MSSA bacteremia are urgently needed.

Risk Factors for Treatment Failure and Mortality Among Hospitalized Patients With Complicated Urinary Tract Infection: A Multicenter Retrospective Cohort Study (RESCUING Study Group).

Background: Complicated urinary tract infections (cUTIs) are responsible for a major share of all antibiotic consumption in hospitals. We aim to describe risk factors for treatment failure and mortality among patients with cUTIs. Methods: A multinational, multicentre retrospective cohort study, conducted in 20 countries in Europe and the Middle East. Data were collected from patients' files on hospitalised patients with a diagnosis of cUTI during 2013-2014. Primary outcome was treatment failure, secondary outcomes included 30 days all-cause mortality,among other outcomes. Multivariable analysis using a logistic model and the hospital as a random variable was performed to identify independent predictors for these outcomes. Results: A total of 981 patients with cUTI were included. Treatment failure was observed in 26.6% (261/981), all cause 30-day mortality rate was 8.7% (85/976), most of these in patients with catheter related UTI (CaUTI). Risk factors for treatment failure in multivariable analysis were ICU admission (OR 5.07, 95% CI 3.18-8.07), septic shock (OR 1.92, 95% CI 0.93-3.98), corticosteroid treatment (OR 1.92, 95% CI 1.12-3.54), bedridden (OR 2.11, 95%CI 1.4-3.18), older age (OR 1.02, 95% CI 1.0071.03-), metastatic cancer (OR 2.89, 95% CI 1.46-5.73) and CaUTI (OR 1.48, 95% CI 1.04-2.11). Management variables, such as inappropriate empirical antibiotic treatment or days to starting antibiotics were not associated with treatment failure or 30-day mortality. More patients with pyelonephritis were given appropriate empirical antibiotic therapy than other CaUTI [110/171; 64.3% vs. 116/270; 43%, p <0.005], nevertheless, this afforded no advantage in treatment failure rates nor mortality in these patients. Conclusions: In patients with cUTI we found no benefit of early appropriate empirical treatment on survival rates or other outcomes. Physicians might consider supportive treatment and watchful waiting in stable patients until the causative pathogen is defined.

The Combination of Daptomycin and Fosfomycin Has Synergistic, Potent, and Rapid Bactericidal Activity against Methicillin-Resistant Staphylococcus aureus in a Rabbit Model of Experimental Endocarditis.

We investigated whether the addition of fosfomycin or cloxacillin to daptomycin provides better outcomes in the treatment of methicillin-resistant Staphylococcus aureus (MRSA) experimental aortic endocarditis in rabbits. Five MRSA strains were used to perform in vitro time-kill studies using standard (106) and high (108) inocula. Combined therapy was compared to daptomycin monotherapy treatment in the MRSA experimental endocarditis model. A human-like pharmacokinetics model was applied, and the equivalents of cloxacillin at 2 g/4 h, fosfomycin at 2 g/6 h, and daptomycin at 6 to 10 mg/kg/day were administered intravenously. A combination of daptomycin and either fosfomycin or cloxacillin was synergistic in the five strains tested at both inocula. A bactericidal effect was detected in four of five strains tested with both combinations. The MRSA-277 strain (vancomycin MIC, 2 µg/ml) was used for the experimental endocarditis model. Daptomycin plus fosfomycin significantly improved the efficacy of daptomycin monotherapy at 6 mg/kg/day in terms of both the proportion of sterile vegetations (100% versus 72%, P = 0.046) and the decrease in the density of bacteria within the vegetations (P = 0.025). Daptomycin plus fosfomycin was as effective as daptomycin monotherapy at 10 mg/kg/day (100% versus 93%, P = 1.00) and had activity similar to that of daptomycin plus cloxacillin when daptomycin was administered at 6 mg/kg/day (100% versus 88%, P = 0.48). Daptomycin nonsusceptibility was not detected in any of the isolates recovered from vegetations. In conclusion, for the treatment of MRSA experimental endocarditis, the combination of daptomycin plus fosfomycin showed synergistic and bactericidal activity.

High vancomycin MICs predict the development of infective endocarditis in patients with catheter-related bacteraemia due to methicillin-resistant Staphylococcus aureus.

Background: It has been suggested that there is an increased risk of treatment failure in episodes of MRSA bloodstream infection (BSI) caused by strains with high vancomycin MICs. However, it is unknown if this phenomenon may also act as a risk factor for the development of infective endocarditis (IE). Methods: We analysed 207 episodes of catheter-related (CR)-BSI recruited from June 2008 to December 2009 within a prospective study on MRSA BSI in 21 Spanish hospitals. Vancomycin susceptibility was centrally tested. The impact of high vancomycin MIC values (≥1.5 mg/L by Etest) on the subsequent development of IE was investigated by Cox regression. Results: High vancomycin MIC values were observed in 46.9% of the isolates. Initial therapy consisted of vancomycin [99 episodes (44.7%)], daptomycin [25 (12.1%)], linezolid [18 (8.7%)] and other antistaphylococcal agents [16 (7.7%)]. Haematogenous complications occurred in 41 patients (19.8%), including 10 episodes complicated by IE. Early (48 h) and late (30 day) all-cause mortality were 3.4% and 25.1%, respectively. High vancomycin MIC isolates were more common among patients that developed IE compared with those free from this complication [90.9% (9/10) versus 44.7% (88/197); P = 0.007]. This association remained significant after adjusting for multiple confounders (including initial antibiotic therapy and catheter removal) in different models (minimum hazard ratio: 9.18; 95% CI: 1.16-72.78; P = 0.036). There were no differences in mortality according to vancomycin MIC values. Conclusions: Decreased susceptibility to vancomycin acted as a predictor of the development of IE complicating MRSA CR-BSI.

Prevalence of healthcare-associated infections in long-term care facilities in Catalonia. VINCat Program. / Prevalencia de infección relacionada con la asistencia sanitaria en centros sanitarios de cuidados prolongados de Cataluña. Programa de Vigilancia de la Infección Nosocomial en Cataluña (VINCat).

INTRODUCTION: Long-term care facilities (LTCFs) have become receptors of patients with a high risk of healthcare-associated infections (HAIs). OBJECTIVE: To determine the prevalence of HAIs in LTCFs. METHOD: During the period 2011-2014 2 annual prevalence studies were performed according to Healthcare-associated infections in long-term-care facilities (HALT) study definitions and methodology. RESULTS: A total of 28,360 patients were included in the study. The overall prevalence rate of HAIs was 10.2%. Subacute units and palliative care units showed the highest rates, 22.3% and 18.7%, respectively. Main infections were respiratory tract infection (35.8%) and urinary tract infection (35.8%). CONCLUSION: These results were higher than other similar experiences, a fact that suggests the need to extend the specific strategies and programs to LTCFs, and ensuring a sufficient number of specialised staff in infection control.

High MICs for Vancomycin and Daptomycin and Complicated Catheter-Related Bloodstream Infections with Methicillin-Sensitive Staphylococcus aureus.

We investigated the prognostic role of high MICs for antistaphylococcal agents in patients with methicillin-sensitive Staphylococcus aureus catheter-related bloodstream infection (MSSA CRBSI). We prospectively reviewed 83 episodes from 5 centers in Spain during April 2011-June 2014 that had optimized clinical management and analyzed the relationship between E-test MICs for vancomycin, daptomycin, oxacillin, and linezolid and development of complicated bacteremia by using multivariate analysis. Complicated MSSA CRBSI occurred in 26 (31.3%) patients; MICs for vancomycin and daptomycin were higher in these patients (optimal cutoff values for predictive accuracy = 1.5 µg/mL and 0.5 µg/mL). High MICs for vancomycin (hazard ratio 2.4, 95% CI 1.2-5.5) and daptomycin (hazard ratio 2.4, 95% CI 1.1-5.9) were independent risk factors for development of complicated MSSA CRBSI. Our data suggest that patients with MSSA CRBSI caused by strains that have high MICs for vancomycin or daptomycin are at increased risk for complications.

Carbapenem-resistant and carbapenem-susceptible isogenic isolates of Klebsiella pneumoniae ST101 causing infection in a tertiary hospital.

BACKGROUND: In this study we describe the clinical and molecular characteristics of an outbreak due to carbapenem-resistant Klebsiella pneumoniae (CR-KP) producing CTX-M-15 and OXA-48 carbapenemase. Isogenic strains, carbapenem-susceptible K. pneumoniae (CS-KP) producing CTX-M-15, were also involved in the outbreak. RESULTS: From October 2010 to December 2012 a total of 62 CR-KP and 23 CS-KP were isolated from clinical samples of 42 patients (22 had resistant isolates, 14 had susceptible isolates, and 6 had both CR and CS isolates). All patients had underlying diseases and 17 of them (14 patients with CR-KP and 3 with CS-KP) had received carbapenems previously. The range of carbapenem MICs for total isolates were: imipenem: 2 to >32 µg/ml vs. <2 µg/ml; meropenem: 4 to >32 µg/ml vs. <2 µg/ml; and ertapenem: 8 to >32 µg/ml vs. <2 µg/ml. All the isolates were also resistant to gentamicin, ciprofloxacin, and cotrimoxazole. Both types of isolates shared a common PFGE pattern associated with the multilocus sequence type 101 (ST101). The bla CTX-M-15 gene was detected in all the isolates, whereas the bla OXA-48 gene was only detected in CR-KP isolates on a 70 kb plasmid. CONCLUSIONS: The clonal spread of K. pneumoniae ST101 expressing the OXA-48 and CTX-M-15 beta-lactamases was the cause of an outbreak of CR-KP infections. CTX-M-15-producing isolates lacking the bla OXA-48 gene coexisted during the outbreak.

Prevalence of methicillin-resistant Staphylococcus aureus colonization in HIV-infected patients in Barcelona, Spain: a cross-sectional study.

BACKGROUND: Colonization by community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has been found to be markedly more common in HIV-infected individuals in the USA. Studies evaluating the prevalence MRSA colonization in HIV-infected populations in Europe are scarce. The aim of this study was to investigate the prevalence of MRSA colonization in a cohort of HIV-infected patients in Barcelona, Spain. METHODS: Nasal and pharyngeal S. aureus carriage was assessed in a random sample of 190 patients from an outpatient HIV clinic. Nasal and pharyngeal swab specimens were obtained for staphylococcal culture from 190 and 110 patients respectively. All MRSA isolates were screened for Panton-Valentine leukocidin (PVL) genes by PCR. Molecular characterization of MRSA isolates was performed by multilocus sequence typing. Data related to HIV infection, healthcare exposure, and previously described risk factors for MRSA were collected from medical records and a questionnaire administered to each patient. RESULTS: The patients' characteristics were as follows: male, 83 %; median (IQR) age, 45 (39-49) years; intravenous drug users, 39 %; men who have sex with men, 32 %; heterosexual, 26 %; CD4 count, 528/µL (IQR 351-740); on antiretroviral therapy, 96 %; and undetectable plasma viral load, 80 %. Sixty-five patients (34 %) were colonized by S. aureus. MRSA colonization was found in 1 % and 2 % of nasal and pharyngeal samples respectively. No PVL positive MRSA strains were detected and all the MRSA isolates belonged to typical hospital-acquired clones. CONCLUSIONS: Our data suggest that CA-MRSA colonization is not currently a problem in HIV-infected individuals in our area.

Methicillin-resistant Staphylococcus aureus (MRSA) catheter-related bacteraemia in haemodialysis patients.

BACKGROUND: The aim of the study was to determine clinical and microbiological differences between patients with methicillin-resistant Staphylococcus aureus (MRSA) catheter-related bacteraemia (CRB) undergoing or not undergoing haemodialysis, and to compare outcomes. METHODS: Prospective multicentre study conducted at 21 Spanish hospitals of patients with MRSA bacteraemia diagnosed between June 2008 and December 2009. Patients with MRSA-CRB were selected. Data of patients on haemodialysis (HD-CRB) and those not on haemodialysis (non-HD-CRB) were compared. RESULTS: Among 579 episodes of MRSA bacteraemia, 218 (37.7%) were CRB. Thirty-four (15.6%) were HD-CRB and 184 (84.4%) non-HD-CRB. All HD-CRB patients acquired the infection at dialysis centres, while in 85.3% of the non-HD-CRB group the infection was nosocomial (p < .001). There were no differences in age, gender or severity of bacteraemia (Pitt score); comorbidities (Charlson score ≥ 4) were higher in the HD-CRB group than in the non-HD-CRB group (73.5% vs. 46.2%, p = .003). Although there were no differences in VAN-MIC ≥ 1.5 mg/L according to microdilution, using the E-test a higher rate of VAN-MIC ≥ 1.5 mg/L was observed in HD-CRB than in non-HD-CRB patients (63.3% vs. 44.1%, p = .051). Vancomycin was more frequently administered in the HD-CRB group than in the non-HD-CRB group (82.3% vs. 42.4%, p = <.001) and therefore the appropriate empirical therapy was significantly higher in HD-CRB group (91.2% vs. 73.9%, p = .029). There were no differences with regard to catheter removal (79.4% vs. 84.2%, p = .555, respectively). No significant differences in mortality rate were observed between both groups (Overall mortality: 11.8% vs. 27.2%, p = .081, respectively), but there was a trend towards a higher recurrence rate in HD-CRB group (8.8% vs. 2.2%, p = .076). CONCLUSIONS: In our multicentre study, ambulatory patients in chronic haemodialysis represented a significant proportion of cases of MRSA catheter-related bacteraemia. Although haemodialysis patients with MRSA catheter-related bacteraemia had significantly more comorbidities and higher proportion of strains with reduced vancomycin susceptibility than non-haemodialysis patients, overall mortality between both groups was similar.

Diagnosis and treatment of bacteremia and endocarditis due to Staphylococcus aureus. A clinical guideline from the Spanish Society of Clinical Microbiology and Infectious Diseases (SEIMC).

Both bacteremia and infective endocarditis caused by Staphylococcus aureus are common and severe diseases. The prognosis may darken not infrequently, especially in the presence of intracardiac devices or methicillin-resistance. Indeed, the optimization of the antimicrobial therapy is a key step in the outcome of these infections. The high rates of treatment failure and the increasing interest in the influence of vancomycin susceptibility in the outcome of infections caused by both methicillin-susceptible and -resistant isolates has led to the research of novel therapeutic schemes. Specifically, the interest raised in recent years on the new antimicrobials with activity against methicillin-resistant staphylococci has been also extended to infections caused by susceptible strains, which still carry the most important burden of infection. Recent clinical and experimental research has focused in the activity of new combinations of antimicrobials, their indication and role still being debatable. Also, the impact of an appropriate empirical antimicrobial treatment has acquired relevance in recent years. Finally, it is noteworthy the impact of the implementation of a systematic bundle of measures for improving the outcome. The aim of this clinical guideline is to provide an ensemble of recommendations in order to improve the treatment and prognosis of bacteremia and infective endocarditis caused by S. aureus, in accordance to the latest evidence published.

Executive summary of the diagnosis and treatment of bacteremia and endocarditis due to Staphylococcus aureus. A clinical guideline from the Spanish Society of Clinical Microbiology and Infectious Diseases (SEIMC).

Bacteremia and infective endocarditis caused by Staphylococcus aureus are common and severe diseases. Optimization of treatment is fundamental in the prognosis of these infections. The high rates of treatment failure and the increasing interest in the influence of vancomycin susceptibility in the outcome of infections caused by both methicillin-susceptible and -resistant isolates have led to research on novel therapeutic schemes. The interest in the new antimicrobials with activity against methicillin-resistant staphylococci has been extended to susceptible strains, which still carry the most important burden of infection. New combinations of antimicrobials have been investigated in experimental and clinical studies, but their role is still being debated. Also, the appropriateness of the initial empirical therapy has acquired relevance in recent years. The aim of this guideline is to update the 2009 guidelines and to provide an ensemble of recommendations in order to improve the treatment of staphylococcal bacteremia and infective endocarditis, in accordance with the latest published evidence.