Time trends in the aetiology of prosthetic joint infections: a multicentre cohort study

It is important to know the spectrum of the microbial aetiology of prosthetic joint infections (PJIs) to guide empiric treatment and establish antimicrobial prophylaxis in joint replacements. There are no available data based on large contemporary patient cohorts. We sought to characterize the causative pathogens of PJIs and to evaluate trends in the microbial aetiology. We hypothesized that the frequency of antimicrobial-resistant organisms in PJIs has increased in the recent years. We performed a cohort study in 19 hospitals in Spain, from 2003 to 2012. For each 2-year period (2003-2004 to 2011-2012), the incidence of microorganisms causing PJIs and multidrug-resistant bacteria was assessed. Temporal trends over the study period were evaluated. We included 2524 consecutive adult patients with a diagnosis of PJI. A microbiological diagnosis was obtained for 2288 cases (90.6%). Staphylococci were the most common cause of infection (1492, 65.2%). However, a statistically significant rising linear trend was observed for the proportion of infections caused by Gram-negative bacilli, mainly due to the increase in the last 2-year period (25% in 2003-2004, 33.3% in 2011-2012; p 0.024 for trend). No particular species contributed disproportionally to this overall increase. The percentage of multidrug-resistant bacteria PJIs increased from 9.3% in 2003-2004 to 15.8% in 2011-2012 (p 0.008), mainly because of the significant rise in multidrug-resistant Gram-negative bacilli (from 5.3% in 2003-2004 to 8.2% in 2011-2012; p 0.032). The observed trends have important implications for the management of PJIs and prophylaxis in joint replacements.

Staphylococcus aureus bacteremic pneumonia

Staphylococcus aureus bacteremic pneumonia is an uncommon cause of hospitalization, with a high mortality rate. However, published reports are scarce and have included a small number of cases. All patients with S. aureus bacteremic pneumonia were prospectively collected in our institution from 2000 to 2014, and a retrospective revision was performed to identify risk factors associated with methicillin resistance and to update the mortality of this entity. A total of 98 patients were admitted: 57.1 % were due to methicillin-susceptible S. aureus (MSSA) and 42.8 % due to methicillin-resistant S. aureus (MRSA). In 40 patients (40.8 %), the infection was community acquired. Thirteen were ventilator-associated pneumonia episodes. The most frequent comorbidities were chronic lung disease (34.7 %), chronic renal failure (31.6 %), diabetes mellitus (29.6 %), and cardiovascular disease (31.6 %). Septic shock was present in 46 patients (46.9 %). The 30-day mortality was 46.9 %. MRSA infections occurred in older patients, more frequently with cardiovascular diseases, and they had received antibiotic treatment in the previous month more often than MSSA-infected patients. Patients with infection due to MSSA presented more frequently with septic shock, but they received more frequently appropriate empirical antibiotic therapy than patients with MRSA pneumonia (96 % vs. 38.1 %), and no differences in mortality were observed between both groups. In conclusion, S. aureus bacteremic pneumonia is a severe infection that, nowadays, affects people with comorbidities and the mortality is still high.

Clinical and microbiological findings in prosthetic joint replacement due to aseptic loosening

OBJECTIVES

A role for microorganisms in aseptic prosthetic loosening (AL) is postulated. We analyse the microbiological and clinical findings of patients with suspected AL, and compare them with patients with chronic prosthetic joint infection (PJI).

METHODS

Prospective study (2011-2012) of patients with presumed AL. Evaluation of tissue samples (≥5; TS) at the time of surgery and sonication fluid (SF) of prosthesis.

RESULTS

According to positive culture in TS/SF, 89 patients were divided into: Group1: (≥2 positive-TS; n = 12); Group2: single positive-TS and concordant SF (n = 10); Group3: one positive or non-concordant TS or SF (n = 38); and Group4: cultures negative (n = 29). Positive-SF was always concordant with TS in Group 1 (75%); it was positive in 74% in Group 3. Median months (prosthesis-age: implantation to revision arthroplasty) for PJI and Group 1-4 was 21, 46, 65, 63 and 81, respectively (P < 0.001); they also had a different dynamic trend in prosthesis failure (P < 0.001).

CONCLUSIONS

Several patients with suspected AL are misdiagnosed PJI. Results from SF correlated well with TS in Group 1, led us to consider single positive-TS as significant (Group 2) and to suggest that microorganisms were on the prosthesis (Group 3). We observed a correlation between microbiology and prosthesis-age, which supports that early loosening is more often caused by hidden PJI than late loosening.

Current time-to-positivity of blood cultures in febrile neutropenia: a tool to be used in stewardship de-escalation strategies

OBJECTIVES

We aimed to describe the current time-to-positivity (TTP) of blood cultures in individuals with onco-haematological diseases with febrile neutropenia. We assessed the probability of having a multidrug-resistant Gram-negative bacilli (MDR-GNB) bloodstream infection (BSI) 24 h after cultures were taken, to use this information for antibiotic de-escalation strategies.

METHODS

BSI episodes were prospectively collected (2003-2017). When a patient experienced more than one BSI, only one episode was randomly chosen. Time elapsed from the beginning of incubation to a positive reading was observed; TTP was recorded when the first bottle had a positive result.

RESULTS

Of the 850 patient-unique episodes, 323 (38%) occurred in acute leukaemia, 185 (21.8%) in non-Hodgkin's lymphoma and 144 (16.9%) in solid neoplasms. Coagulase-negative staphylococci (225; 26.5%), Escherichia coli (207; 26.1%), Pseudomonas aeruginosa (136; 16%), Enterococcus spp. (81; 9.5%) and Klebsiella pneumoniae (67; 7.9%), were the most frequent microorganisms isolated. MDR-GNB were documented in 126 (14.8%) episodes. Median TTP was 12 h (interquartile range 9-16.5 h). Within the first 24 h, 92.1% of blood cultures were positive (783/850). No MDR-GNB was positive over 24 h. Of the 67 (7.9%) episodes with a TTP ≥24 h, 25 (37.3%) occurred in patients who were already receiving active antibiotics against the isolated pathogen. Most common isolations with TTP ≥24 h were coagulase-negative staphylococci, candidaemia and a group of anaerobic GNB.

CONCLUSIONS

Currently, the vast majority of BSI in individuals with onco-haematological diseases with febrile neutropenia have a TTP <24 h, including all episodes caused by MDR-GNB. Our results support reassessing empiric antibiotic treatment in neutropenic patients at 24 h, to apply antibiotic stewardship de-escalation strategies.

Predictors of multidrug-resistant Pseudomonas aeruginosa in neutropenic patients with bloodstream infection

OBJECTIVES

To assess risk factors for multidrug-resistant Pseudomonas aeruginosa (MDR-PA) infection in neutropenic patients.

METHODS

Single-centre retrospective analysis of consecutive bloodstream infection (BSI) episodes (2004-2017, Barcelona). Two multivariate regression models were used at BSI diagnosis and P. aeruginosa detection. Significant predictors were used to establish rules for stratifying patients according to MDR-PA BSI risk.

RESULTS

Of 661 Gram-negative BSI episodes, 190 (28.7%) were caused by P. aeruginosa (70 MDR-PA). Independent factors associated with MDR-PA among Gram-negative organisms were haematological malignancy (OR 3.30; 95% CI 1.15-9.50), pulmonary source of infection (OR 7.85; 95% CI 3.32-18.56), nosocomial-acquired BSI (OR 3.52; 95% CI 1.74-7.09), previous antipseudomonal cephalosporin (OR 13.66; 95% CI 6.64-28.10) and piperacillin/tazobactam (OR 2.42; 95% CI 1.04-5.63), and BSI occurring during ceftriaxone (OR 4.27; 95% CI 1.15-15.83). Once P. aeruginosa was identified as the BSI aetiological pathogen, nosocomial acquisition (OR 7.13; 95% CI 2.87-17.67), haematological malignancy (OR 3.44; 95% CI 1.07-10.98), previous antipseudomonal cephalosporin (OR 3.82; 95% CI 1.42-10.22) and quinolones (OR 3.97; 95% CI 1.37-11.48), corticosteroids (OR 2.92; 95% CI 1.15-7.40), and BSI occurring during quinolone (OR 4.88; 95% CI 1.58-15.05) and β-lactam other than ertapenem (OR 4.51; 95% CI 1.45-14.04) were independently associated with MDR-PA. Per regression coefficients, 1 point was assigned to each parameter, except for nosocomial-acquired BSI (3 points). In the second analysis, a score >3 points identified 60 (86.3%) out of 70 individuals with MDR-PA BSI and discarded 100 (84.2%) out of 120 with non-MDR-PA BSI.

CONCLUSIONS

A simple score based on demographic and clinical factors allows stratification of individuals with bacteraemia according to their risk of MDR-PA BSI, and may help facilitate the use of rapid MDR-detection tools and improve early antibiotic appropriateness.

Risk factors associated with high linezolid trough plasma concentrations

AIM

The major concern of linezolid is the adverse events. High linezolid trough serum concentration (Cmin) has been associated with toxicity. The aim of this study was to analyze factors associated with high Cmin.

METHODS

Main clinical characteristics of 104 patients treated with 600 mg/12 hours of linezolid were retrospectively reviewed. Samples were obtained just before the next dose after at least three doses and within the first 8 days of treatment. High Cmin was considered when it was >8 mg/L. Univariate and multivariate analysis were performed.

RESULTS

34.6% patients had a Cmin >8 mg/L, and they were older and had more frequently an estimated glomerular filtration by MDRD <40 mL/min. There were more patients co-treated with rifampin in the group with low Cmin. The only factor independently associated with Cmin >8 was the renal function. Patients with an eGF < 40 mL/min had significantly higher Cmin than those with eGF > 80 mL/min (OR: 4.273) and there was a trend towards a high Cmin in patients with eGF between 40-80 mL/min (OR: 2.109).

CONCLUSIONS

High Cmin were frequent, especially in patients with MDRD <40 mL/min. Therapeutic drug monitoring could be useful to avoid toxicity in patients with renal dysfunction.

Real-life use of remdesivir in hospitalized patients with COVID-19

Objective

Controversial results on remdesivir efficacy have been reported. We aimed to report our real-life experience with the use of remdesivir from its availability in Spain.

Methods

We performed a descriptive study of all patients admitted for ≥48 hours with confirmed COVID-19 who received remdesivir between the 1st of July and the 30th of September 2020.

Results

A total of 123 patients out of 242 admitted with COVID-19 at our hospital (50.8%) received remdesivir. Median age was 58 years, 61% were males and 56.9 % received at least one anti-inflammatory treatment. No adverse events requiring remdesivir discontinuation were reported. The need of intensive care unit admission, mechanical ventilation and 30-days mortality were 19.5%, 7.3% and 4.1%, respectively.

Conclusion

In our real-life experience, the use of remdesivir in hospitalized patients with COVID-19 was associated with a low mortality rate and good safety profile.

Performance of differential time to positivity as a routine diagnostic test for catheter-related bloodstream infections: a single-centre experience

OBJECTIVE

To assess the performance of differential time to positivity (DTP) for the diagnosis of catheter-related bloodstream infections (CRBSI).

METHODS

From all episodes of bloodstream infections (BSI) diagnosed during a 15-year period (2003-17) those in which a paired set of blood cultures drawn from a catheter and a peripheral vein were positive for the same microorganism and had a clinically and/or microbiologically defined source were selected. To assess diagnostic discrimination ability and accuracy of DTP for CRBSI, area under the receiver operating characteristic curves (AUC) and performance characteristics of a DTP ≥2 h were computed.

RESULTS

A total of 512 BSI were included, of which 302 (59%) were CRBSI. Discrimination ability of DTP was low for Staphylococcus aureus (AUC 0.656 ± 0.06), coagulase-negative staphylococci (AUC 0.618 ± 0.081), enterococci (AUC 0.554 ± 0.117) and non-AmpC-producing Enterobacteriaceae (AUC 0.653 ± 0.053); moderate for Pseudomonas aeruginosa (AUC 0.841 ± 0.073), and high for AmpC-producing Enterobacteriaceae (AUC 0.944 ± 0.039). For the entire sample, DTP had a low-to-moderate discrimination ability (AUC 0.698 ± 0.024). A DTP ≥2 h has a low sensitivity for coagulase-negative staphylococci (60%) and very low for S. aureus (34%), enterococci (40%) and non-AmpC-producing Enterobacteriaceae (42%). A DTP cut-off of 1 h improved sensitivity (90%) for AmpC-producing Enterobacteriaceae.

CONCLUSIONS

Differential time to positivity performs well for diagnosing CRBSI only when AmpC-producing Enterobacteriaceae and P. aeruginosa are involved. Performance is low for common Gram-positive organisms and non-AmpC-producing enteric bacilli; a negative test should not be used to rule out CRBSI due to these microorganisms. A DTP ≥1 h may improve accuracy for AmpC-producing Enterobacteriaceae, particularly Enterobacter spp.

An evidence-based bundle improves the quality of care and outcomes of patients with candidaemia

Background

Candidaemia is a leading cause of bloodstream infections in hospitalized patients all over the world. It remains associated with high mortality.

Objectives

To assess the impact of implementing an evidence-based package of measures (bundle) on the quality of care and outcomes of candidaemia.

Methods

A systematic review of the literature was performed to identify measures related to better outcomes in candidaemia. Eight quality-of-care indicators (QCIs) were identified and a set of written recommendations (early treatment, echinocandins in septic shock, source control, follow-up blood culture, ophthalmoscopy, echocardiography, de-escalation, length of treatment) was prospectively implemented. The study was performed in 11 tertiary hospitals in Spain. A quasi-experimental design before and during bundle implementation (September 2016 to February 2018) was used. For the pre-intervention period, data from the prospective national surveillance were used (May 2010 to April 2011).

Results

A total of 385 and 263 episodes were included in the pre-intervention and intervention groups, respectively. Adherence to all QCIs improved in the intervention group. The intervention group had a decrease in early (OR 0.46; 95% CI 0.23–0.89; P = 0.022) and overall (OR 0.61; 95% CI 0.4–0.94; P = 0.023) mortality after controlling for potential confounders.

Conclusions

Implementing a structured, evidence-based intervention bundle significantly improved patient care and early and overall mortality in patients with candidaemia. Institutions should embrace this objective strategy and use the bundle as a means to measure high-quality medical care of patients.

Effectiveness of sequential intravenous-to-oral antibiotic switch therapy in hospitalized patients with gram-positive infection: the SEQUENCE cohort study

Switching from intravenous to oral antibiotic therapy may improve inpatient management and reduce hospital stays and the complications of intravenous treatment. We aimed to assess the effectiveness of intravenous-to-oral antibiotic switch therapy and an early discharge algorithm in hospitalized patients with gram-positive infection. We performed a prospective cohort study with a retrospective comparison cohort, recruited from eight tertiary, acute-care Spanish referral hospitals. All patients included had culture-confirmed methicillin-resistant gram-positive infection, or methicillin-susceptible gram-positive infection and beta-lactam allergy and had received intravenous treatment with glycopeptides, lipopeptides, or linezolid. The study comprised two cohorts: the prospective cohort to assess the effectiveness of a sequential intravenous-to-oral antibiotic switch algorithm and early discharge, and a retrospective cohort in which the algorithm had not been applied, used as the comparator. A total of 247 evaluable patients were included; 115 in the prospective and 132 in the retrospective cohort. Forty-five retrospective patients (34 %) were not changed to oral antibiotics, and 87 (66 %) were changed to oral antibiotics without following the proposed algorithm. The duration of hospitalization was significantly shorter in the prospective cohort compared to the retrospective group that did not switch to oral drugs (16.7 ± 18.7 vs 23 ± 13.4 days, P  < 0.001). No differences were observed regarding the incidence of catheter-related bacteraemia (4.4 % vs 2.6 %, P = 0.621). Our results suggest that an intravenous-to-oral antibiotic switch strategy is effective for reducing the length of hospital stay in selected hospitalized patients with gram-positive infection.

Effectiveness of combination therapy versus monotherapy with a third-generation cephalosporin in bacteraemic pneumococcal pneumonia: A propensity score analysis

OBJECTIVE

Combining a macrolide or a fluoroquinolone to beta-lactam regimens in the treatment of patients with moderate to severe community-acquired pneumonia is recommended by the international guidelines. However, the information in patients with bacteraemic pneumococcal pneumonia is limited.

METHODS

A propensity score technique was used to analyze prospectively collected data from all patients with bacteraemic pneumococcal pneumonia admitted from 2000 to 2015 in our institution, who had received empirical treatment with third-generation cephalosporin in monotherapy or plus macrolide or fluoroquinolone.

RESULTS

We included 69 patients in the monotherapy group and 314 in the combination group. After adjustment by PS for receiving monotherapy, 30-day mortality (OR 2.89; 95% CI 1.07-7.84) was significantly higher in monotherapy group. A higher 30-day mortality was observed in monotherapy group in both 1:1 and 1:2 matched samples although it was statistically significant only in 1:2 sample (OR: 3.50 (95% CI 1.03-11.96), P = 0.046).

CONCLUSIONS

Our study suggests that in bacteraemic pneumococcal pneumonia, empirical therapy with a third-generation cephalosporin plus a macrolide or a fluoroquinolone is associated with a lower mortality rate than beta-lactams in monotherapy. These results support the recommendation of combination therapy in patients requiring admission with moderate to severe disease.

Experience with the use of siltuximab in patients with SARS-CoV-2 infection

OBJECTIVE

The study aims to describe characteristics and clinical outcome of patients with SARS-CoV-2 infection that received siltuximab according to a protocol that aimed to early block the activity of IL-6 to avoid the progression of the inflammatory flare.

METHODS

Retrospective review of the first 31 patients with SARS-CoV-2 treated with siltuximab, in Hospital Clinic of Barcelona or Hospital Universitario Salamanca, from March to April 2020 with positive polymerase-chain reaction (PCR) from a nasopharyngeal swab.

RESULTS

The cohort included 31 cases that received siltuximab with a median (IQR) age of 62 (56-71) and 71% were males. The most frequent comorbidity was hypertension (48%). The median dose of siltuximab was 800 mg ranging between 785 and 900 mg. 7 patients received siltuximab as a salvage therapy after one dose of tocilizumab. At the end of the study, a total of 26 (83.9) patients had been discharged alive and the mortality rate was 16.1% but only 1 out of 24 that received siltuximab as a first line option (4%).

CONCLUSIONS

Siltuximab is a well-tolerated alternative to tocilizumab when administered as a first line option in patients with COVID-19 pneumonia within the first 10 days from symptoms onset and high C-reactive protein.

Tocilizumab reduces the risk of ICU admission and mortality in patients with SARS-CoV-2 infection

Objectives

In some patients the immune response triggered by SARS-CoV-2 is unbalanced, presenting an acute respiratory distress syndrome which in many cases requires intensive care unit (ICU) admission. The limitation of ICU beds has been one of the major burdens in the management around the world; therefore, clinical strategies to avoid ICU admission are needed. We aimed to describe the influence of tocilizumab on the need of transfer to ICU or death in non-critically ill patients.

Material and methods

A retrospective study of 171 patients with SARS-CoV-2 infection that did not qualify as requiring transfer to ICU during the first 24h after admission to a conventional ward, were included. The criteria to receive tocilizumab was radiological impairment, oxygen demand or an increasing of inflammatory parameters, however, the ultimate decision was left to the attending physician judgement. The primary outcome was the need of ICU admission or death whichever came first.

Results

A total of 77 patients received tocilizumab and 94 did not. The tocilizumab group had less ICU admissions (10.3% vs. 27.6%, P=0.005) and need of invasive ventilation (0 vs 13.8%, P=0.001). In the multivariable analysis, tocilizumab remained as a protective variable (OR: 0.03, CI 95%: 0.007-0.1, P=0.0001) of ICU admission or death.

Conclusions

Tocilizumab in early stages of the inflammatory flare could reduce an important number of ICU admissions and mechanical ventilation. The mortality rate of 10.3% among patients receiving tocilizumab appears to be lower than other reports. This is a non-randomized study and the results should be interpreted with caution.

Acquisition of resistant microorganisms and infections in HIV-infected patients admitted to the ICU

Whether critically ill human immunodeficiency virus (HIV)-infected patients are at risk of acquiring nosocomial infections and resistant or potentially resistant microorganisms (RPRMs) remains to be clarified. The aim was to compare the acquisition of RPRMs, infections and mortality in critically ill HIV-infected and non-infected patients. An observational, prospective cohort study of patients admitted to a medical intensive care unit (ICU) was undertaken. Swabbing of nares, pharynx and rectum, and culture of respiratory secretions were obtained within 48 h of admission and thrice weekly thereafter. Clinical samples were obtained as deemed necessary by the attending physician. Clinical variables, severity scores on admission and exposures during ICU stay were collected. Logistic regression was used to evaluate ICU mortality. Out of the 969 included patients, 64 (6.6%) were HIV-infected. These patients had a higher Acute Physiology and Chronic Health Evaluation (APACHE) II score on admission (19.5 ± 6.6 vs. 21.1 ± 5.4, p = 0.02), stayed longer in the care unit and were more exposed to several invasive devices and antibiotics. There were no differences in the rate of acquisition of RPRMs and the only difference in ICU-acquired infections was a significantly higher incidence of catheter-related bacteraemia (3% vs. 9%, p = 0.03). The ICU-related mortality was similar in both groups (14% vs. 16%, p = 0.70) and in HIV-infected patients, it tended to be associated with a lower CD4 cell count (p = 0.06). Despite a longer ICU stay, critically ill HIV-infected patients did not show a higher rate of RPRMs acquisition. The rate of ICU-acquired infection was similar between HIV-infected and non-infected patients, except for catheter-related bacteraemia, which was higher in the HIV-infected population. Mortality was similar in both groups.

Carriage of multidrug-resistant Gram-negative bacilli: duration and risk factors

Identification of risk factors influencing the duration of carriage of multidrug-resistant Gram-negative bacilli (MDR-GNB) may be useful for infection control. The aim of this study is to estimate the impact of several factors collected for routine hospital surveillance on the duration of carriage of selected MDR-GNB. From January 2015 to July 2021, patients with at least two clinical/surveillance samples positive for MDR-GNB different from ESBL-producing E. coli or AmpC - exclusively producing Enterobacterales were assessed. Microorganisms, age, number of admissions, clinical or rectal sample, sex, and admission service were evaluated as risk factors. Multivariate analysis was performed by a Cox proportional hazard model. A total of 1981 episodes of colonization were included. Involved microorganisms were ESBL-Klebsiella pneumoniae (KP) in 1057 cases (53.4%), other ESBL-non-E. coli Enterobacterales in 91 (4.6%), OXA-48-KP in 263 (13.3%), KPC-KP in 90 (4.5%), VIM-KP in 29 (1.5%), carbapenemase-producing non-KP Enterobacterales (CP-non-KP) in 124 (6.3%), and MDR Pseudomonas aeruginosa (MDR-PAER) in 327 (16.5%). No differences in duration of colonization were observed among ESBL-KP (median colonization time 320 days), ESBL-non-E. coli Enterobacterales (226 days), OXA48-KP (305 days), and MDR-PAER (321 days). For each group, duration of colonization was significantly longer than that of KPC-KP (median colonization time 60 days), VIM-KP (138 days), and CP-non-KP (71 days). Male sex (HR = 0.88; 95% CI 0.78-0.99), detection in Hepatology-Gastroenterology (HR = 0.71; 95% CI 0.54-0.93), clinical sample (HR = 0.61; 95% CI 0.53-0.69), and > 2 admissions after first detection (HR = 0.47; 95% CI 0.42-0.52) were independent predictors of longer carriage, whereas VIM-KP (HR = 1.61; 95% CI 1.04-2.48), KPC-KP (HR = 1.85; 95% CI 1.49-2.3), and CP-non-KP (HR = 1.92; 95% CI 1.49-2.47) were associated with shorter colonization time. Duration of colonization was significantly longer for ESBL-KP, other ESBL-non-E. coli Enterobacterales, OXA-48-KP, and MDR-PAER. For these microorganisms, prolonging surveillance up to 2.5-3 years should be considered. Male sex, clinical sample, multiple readmissions, admission service, and type of microorganism are independent predictors of the duration of carriage.

Comparison of acquisition of resistant microorganisms and infections in critically-ill patients with and without malignancies

BACKGROUND

Patients with malignancies are often considered at risk of acquiring infections by resistant or potentially resistant microorganisms (RPRMs). However, data supporting this contention is scarce. We have compared critically ill patients with haematological malignancies (HM), solid tumours (ST) and without cancer (NC) in terms of acquisition of RPRMs, infections and mortality.

METHODS

Observational, prospective cohort study of patients admitted to a medical intensive care unit (ICU). Swabbing of nares, pharynx and rectum, and culture of respiratory secretions were obtained within 48 h of admission and thrice weekly thereafter. Clinical samples were obtained as deemed necessary by the attending physician. Clinical variables, severity scores on admission and exposures during ICU stay were also collected. Multivariable logistic regression analysis was used to evaluate ICU mortality.

RESULTS

Out of 969 included patients 127 (13.1%) had HM and 93 (9.6%) had ST. Patients with malignancies were more frequently exposed to central venous catheterization, methylprednisolone, and any antipseudomonal antibiotic whereas they were less commonly exposed to invasive mechanical ventilation. Patients with HM were more often admitted with an infection. There were no differences among groups in terms of RPRMs acquisition during ICU stay or prevalence of ICU-acquired infections due to any microorganism, including RPRMs. Having a HM was an independent predictor of mortality regardless of APACHE II score.

CONCLUSION

Critically ill cancer patients did not show a higher rate of RPRMs acquisition nor ICU-acquired infections. Mortality was higher in the HM group and it was not accurately predicted on admission by APACHE II score.

Nanoactuator for Neuronal Optoporation

Light-driven modulation of neuronal activity at high spatial-temporal resolution is becoming of high interest in neuroscience. In addition to optogenetics, nongenetic membrane-targeted nanomachines that alter the electrical state of the neuronal membranes are in demand. Here, we engineered and characterized a photoswitchable conjugated compound (BV-1) that spontaneously partitions into the neuronal membrane and undergoes a charge transfer upon light stimulation. The activity of primary neurons is not affected in the dark, whereas millisecond light pulses of cyan light induce a progressive decrease in membrane resistance and an increase in inward current matched to a progressive depolarization and action potential firing. We found that illumination of BV-1 induces oxidation of membrane phospholipids, which is necessary for the electrophysiological effects and is associated with decreased membrane tension and increased membrane fluidity. Time-resolved atomic force microscopy and molecular dynamics simulations performed on planar lipid bilayers revealed that the underlying mechanism is a light-driven formation of pore-like structures across the plasma membrane. Such a phenomenon decreases membrane resistance and increases permeability to monovalent cations, namely, Na+, mimicking the effects of antifungal polyenes. The same effect on membrane resistance was also observed in nonexcitable cells. When sustained light stimulations are applied, neuronal swelling and death occur. The light-controlled pore-forming properties of BV-1 allow performing "on-demand" light-induced membrane poration to rapidly shift from cell-attached to perforated whole-cell patch-clamp configuration. Administration of BV-1 to ex vivo retinal explants or in vivo primary visual cortex elicited neuronal firing in response to short trains of light stimuli, followed by activity silencing upon prolonged light stimulations. BV-1 represents a versatile molecular nanomachine whose properties can be exploited to induce either photostimulation or space-specific cell death, depending on the pattern and duration of light stimulation.

Time-to-positivity, type of culture media and oxidase test performed on positive blood culture vials to predict Pseudomonas aeruginosa in patients with Gram-negative bacilli bacteraemia

OBJECTIVE

The aim of this study was to determine the usefulness of oxidase test and time-to-positivity (TTP) in aerobic and anaerobic blood culture vials to detect the presence of Pseudomonas aeruginosa in patients with Gram-negative bacilli (GNB) bacteraemia.

METHODS

TTP was recorded for each aerobic and anaerobic blood culture vial of monomicrobial bacteraemia due to GNB. Oxidase test was performed in a pellet of the centrifuged content of the positive blood culture. An algorithm was developed in order to perform the oxidase test efficiently taking into account TTP and type of vial.

RESULTS

A total of 341 episodes of GNB bacteraemia were analysed. Sensitivity, specificity, positive predictive value and negative predictive value of the oxidase test performed on positive vials with GNB to predict P. aeruginosa were 95%, 99%, 91%, and 99%, respectively. When growth was first or exclusively detected in anaerobic vials, P. aeruginosa was never identified hence the performance of the oxidase test could be avoided. When growth was only or first detected in aerobic vials, a TTP≥8h predicted P. aeruginosa in 37% or cases (63 of 169), therefore oxidase test is highly recommended.

CONCLUSIONS

Oxidase test performed onto positive blood culture vials previously selected by TTP and type of vials is an easy and inexpensive way to predict P. aeruginosa. In most cases, this can lead to optimization of treatment in less than 24 hours.

Gel nail polish does not have a negative impact on the nail bacterial burden nor on the quality of hand hygiene with an alcohol-based hand rub

BACKGROUND

The bacterial burden on gel polished (GP) nails, standard polished (SP) nails and unpolished (UP) nails was evaluated before and after hand hygiene (HH) with alcohol-based hand rub.

METHODS

Three GP nails, two SP nails and five UP nails on both hands were analysed in 46 healthcare workers. Nail length was maintained at ≤2 mm during the study. Nail surface cultures were performed on blood agar plates before and after HH on days 1, 4, 7, 14 and 21 after application. Nail bacterial counts were estimated using a Poisson regression procedure, with nail polish group, participant, hand side, finger, evaluation day, and interaction between nail polish group and evaluation day as independent factors.

RESULTS

In total, 460 nails were evaluated: 92 SP nails (20%), 138 GP nails (30%) and 230 UP nails (50%). Before HH, SP nails were associated with a higher bacterial burden than GP nails on day 4, and with a higher bacterial burden than GP nails and UP nails on day 21 (with counts for UP nails higher than those for GP nails). After HH, SP nails had a higher bacterial burden than UP nails and GP nails on day 4, a higher bacterial burden than UP nails on day 14, and a higher bacterial burden than UP nails and GP nails on day 21.

CONCLUSIONS

Compared with UP nails, GP nails were not associated with a higher bacterial burden within 3 weeks of application, and even had a significantly lower bacterial burden before HH on day 21.

Successful prophylactic measures for the eradication of Staphylococcus aureus infections in elective hip primary and revision arthroplasty

INTRODUCTION

Staphylococcus aureus stands as the predominant etiological agent in postoperative acute prosthetic joint infections (PJI), contributing to 35-50% of reported cases. This study aimed to evaluate the efficacy of dual prophylaxis incorporating cefuroxime and teicoplanin, in combination with nasal decolonization utilizing 70% alcohol, and oral and body lavage with chlorhexidine.

MATERIAL AND METHODS

We conducted a retrospective review of electronic health records regarding primary and revision arthroplasties conducted at our institution from 2020 to 2021. Relevant variables linked to prosthetic joint infections (PJI) were documented until the latest follow-up.

RESULTS

A total of 539 operations (447 primary arthroplasties and 92 revision arthroplasties) were performed on 519 patients. There were 11 cases of postoperative acute PJI, resulting in infection rates of 1.6% for primary arthroplasties and 4.3% for revision surgeries. Infections were more prevalent in male patients, individuals with an ASA classification>II, and those undergoing longer operations (>90min). S. aureus was not isolated in any of the cases.

CONCLUSION

The prophylactic measures implemented in our institution have exhibited a high efficacy in preventing postoperative acute PJI caused by S. aureus.

Successful prophylactic measures for the eradication of Staphylococcus aureus infections in elective hip primary and revision arthroplasty

INTRODUCTION

Staphylococcus aureus stands as the predominant etiological agent in postoperative acute prosthetic joint infections (PJI), contributing to 35-50% of reported cases. This study aimed to evaluate the efficacy of dual prophylaxis incorporating cefuroxime and teicoplanin, in combination with nasal decolonization utilizing 70% alcohol, and oral and body lavage with chlorhexidine.

MATERIAL AND METHODS

We conducted a retrospective review of electronic health records regarding primary and revision arthroplasties conducted at our institution from 2020 to 2021. Relevant variables linked to prosthetic joint infections (PJI) were documented until the latest follow-up.

RESULTS

A total of 539 operations (447 primary arthroplasties and 92 revision arthroplasties) were performed on 519 patients. There were 11 cases of postoperative acute PJI, resulting in infection rates of 1.6% for primary arthroplasties and 4.3% for revision surgeries. Infections were more prevalent in male patients, individuals with an ASA classification>II, and those undergoing longer operations (>90min). S. aureus was not isolated in any of the cases.

CONCLUSION

The prophylactic measures implemented in our institution have exhibited a high efficacy in preventing postoperative acute PJI caused by S. aureus.

Strengths and weaknesses of computerized clinical decision support systems: insights from a digital control center (C3 COVID-19) for early and personalized treatment for COVID-19

Clinical Decision Support Systems (CDSS) are computer-based tools that leverage the analysis of large volumes of health data to assist healthcare professionals in making clinical decisions, whether preventive, diagnostic, or therapeutic. This review examines the impact of CDSS on clinical practice, highlighting both their potential benefits and their limitations and challenges. We detail the experience of clinical medical professionals in the development of a virtual control center for COVID-19 patients (C3 COVID-19) in Spain during the SARS-CoV-2 pandemic. This tool enabled real-time monitoring of clinical data for hospitalized COVID-19 patients, optimizing personalized and informed medical decision-making. CDSS can offer significant advantages, such as improving the quality of inpatient care, promoting evidence-based clinical and therapeutic decision-making, facilitating treatment personalization, and enhancing healthcare system efficiency and productivity. However, the implementation of CDSS presents challenges, including the need for physicians to become familiar with the systems and software, and the necessity for ongoing updates and technical support of the systems.