Impact of a multidisciplinary management team on clinical outcome in ICU patients affected by Gram-negative bloodstream infections: a pre-post quasi-experimental study.

BACKGROUND: Bloodstream infections (BSIs) by Gram-negative pathogens play a major role in intensive care patients, both in terms of prevalence and severity, especially if multi-drug resistant pathogens are involved. Early appropriate antibiotic therapy is therefore a cornerstone in the management of these patients, and growing evidence shows that implementation of a multidisciplinary team may improve patients' outcomes. Our aim was to evaluate the clinical and microbiological impact of the application of a multidisciplinary team on critically ill patients. METHODS: Pre-post study enrolling critically ill patients with Gram negative bloodstream infection in intensive care unit. In the pre-intervention phase (from January until December 2018) patients were managed with infectious disease consultation on demand, in the post-intervention phase (from January until December 2022) patients were managed with a daily evaluation by a multidisciplinary team composed of intensivist, infectious disease physician, clinical pharmacologist and microbiologist. RESULTS: Overall, 135 patients were enrolled during the study period, of them 67 (49.6%) in the pre-intervention phase and 68 (50.4%) in the post-intervention phase. Median age was 67 (58-75) years, sex male was 31.9%. Septic shock, the need for continuous renal replacement therapy and mechanical ventilation at BSI onset were similar in both groups, no difference of multidrug-resistant organisms (MDRO) prevalence was observed. In the post-phase, empirical administration of carbapenems decreased significantly (40.3% vs. 62.7%, p = 0.02) with an increase of appropriate empirical therapy (86.9% vs. 55.2%, p < 0.001) and a decrease of overall antibiotic treatment (12 vs. 16 days, p < 0.001). Despite no differences in delta SOFA and all-cause 30-day mortality, a significant decrease in microbiological failure (10.3% vs. 29.9%, p = 0.005) and a new-onset 30-day MDRO colonization (8.3% vs. 36.6%, p < 0.001) in the post-phase was reported. At multivariable analysis adjusted for main covariates, the institution of a multidisciplinary management team (MMT) was found to be protective both for new MDRO colonization [OR 0.17, 95%CI(0.05-0.67)] and microbiological failure [OR 0.37, 95%CI (0.14-0.98)]. CONCLUSIONS: The institution of a MMT allowed for an optimization of antimicrobial treatments, reflecting to a significant decrease in new MDRO colonization and microbiological failure among critically ill patients.

An Improvement in the Antimicrobial Resistance Patterns of Urinary Isolates in the Out-Of-Hospital Setting following Decreased Community Use of Antibiotics during the COVID-19 Pandemic.

After the onset of COVID-19 pandemic, a decrease in antibiotic consumption in the out-of-hospital setting was observed. However, data about the impact of this reduction on antimicrobial resistance are lacking. The aim of this study was to assess antibiotic consumption and antibiotic resistance at the community level in an Italian province before and after the beginning of the COVID-19 pandemic. We carried out an observational study, comparing antibiotic consumption in the community during 2019 and 2020 and the antibiotic resistance patterns of Enterobacterales cultured from urine samples from the out-of-hospital setting during the first semester of 2020 and 2021. Overall, antibiotic consumption decreased by 28% from 2019 to 2020 (from 13.9 to 9.97 DDD/1000 inhabitants/day). The main reductions involved penicillins (ATC J01C, from 6.9 to 4.8 DDD/1000 inhabitants/day, −31%), particularly amoxicillin/clavulanate (ATC J01CR02, −30%) and amoxicillin (J01CA04, −35.2%). Overall, 6445 strains of Enterobacterales were analyzed; in 2020, the susceptibility rate of amoxicillin/clavulanate increased from 57.5% to 87% among isolates from the primary care setting (p < 0.001) and from 39% to 72% (p < 0.001) among isolates from LTCF. The reduction in the community use of antibiotics observed in 2020 was followed by a change in the antimicrobial resistance patterns of urinary isolates.

The burden of colonization and infection by carbapenemase-producing Enterobacteriaceae in the neuro-rehabilitation setting: a prospective six-year experience.

We describe the high burden of carbapenemase-producing Enterobacteriaceae (CPE) colonization and infection in a neuro-rehabilitation hospital in Italy over a 6-year period. Overall, 9.3% of patients were found to be CPE carriers on admission; the rates of CPE in-hospital acquisition and CPE-BSI were 9.2 and 2.9 cases per 10,000 patient days, respectively.

Impact on Mortality of a Bundle for the Management of Enterococcal Bloodstream Infection.

OBJECTIVE: In this study, we evaluated the effectiveness of a management bundle for Enterococcus spp bloodstream infection (E-BSI). METHOD: This was a single-center, quasi-experimental (pre/post) study. In the prephase (January 2014 to December 2015), patients with monomicrobial E-BSI were retrospectively enrolled. During the post- or intervention phase (January 2016 to December 2017), all patients with incident E-BSI were prospectively enrolled in a nonmandatory intervention arm comprising infectious disease consultation, echocardiography, follow-up blood cultures, and early targeted antibiotic treatment. Patients were followed up to 1 year after E-BSI. The primary outcome was 30-day mortality. RESULTS: Overall, 368 patients were enrolled, with 173 in the prephase and 195 in the postphase. The entire bundle was applied in 15% and 61% patients during the pre- and postphase, respectively (P < .001). Patients enrolled in the postphase had a significant lower 30-day mortality rate (20% vs 32%, P = .0042). At multivariate analysis, factors independently associated to mortality were age (hazard ratio [HR], 1.03; 95% confidence interval [CI], 1.00-1.05), intensive care unit admission (HR, 2.51; 95% CI, 1.18-3.89), and healthcare-associated (HR, 2.32; 95% CI, 1.05-5.16) and hospital-acquired infection (HR, 2.85; 95% CI, 1.34-4.76), whereas being enrolled in the postphase period (HR, 0.49; 95% CI, 0.32-0.75) was associated with improved survival. Results were consistent also in the subgroups with severe sepsis (HR, 0.37; 95% CI, 0.16-0.90) or healthcare-associated infections (HR, 0.53; 95% CI, 0.31-0.93). A significantly lower 1-year mortality was observed in patients enrolled in the postphase period (50% vs 68%, P < .001). CONCLUSIONS: The introduction of a bundle for the management of E-BSI was associated with improved 30-day and 1-year survival.

In vivo evolution of resistant subpopulations of KPC-producing Klebsiella pneumoniae during ceftazidime/avibactam treatment.

Objectives: KPC-producing Klebsiella pneumoniae (KPC-Kp) represent a serious problem worldwide. Herein, we describe the evolution of ceftazidime/avibactam resistance by sequencing longitudinal clinical isolates from a patient with KPC-Kp bloodstream infection undergoing ceftazidime/avibactam treatment. Methods: WGS was performed on one ceftazidime/avibactam-susceptible KPC-Kp (BOT-CA-S) and two phenotypically different ceftazidime/avibactam-resistant KPC-Kp with low (BOT-CA-R) and high (BOT-EMO) carbapenem MICs. The population diversity was assessed by the frequency of allele mutations and population analysis profiles (PAPs). Results: Phylogenetic analysis demonstrated clonal relatedness of the KPC-Kp isolates, all belonging to the clone ST1519. The D179Y mutation in blaKPC-3 was detected in both of the ceftazidime/avibactam-resistant KPC-Kp, whereas it was absent in the ceftazidime/avibactam-susceptible isolate. The mutation emerged independently in the two ceftazidime/avibactam-resistant isolates and was associated with a significant reduction in carbapenem MICs in BOT-CA-R, but not in BOT-EMO. WGS analysis revealed that the frequency of the D179Y mutation was 96.32% and 51.05% in BOT-CA-R and BOT-EMO, respectively. PAP results demonstrated that carbapenem resistance in BOT-EMO was due to the coexistence of mixed subpopulations harbouring WT and mutated blaKPC-3. A bacterial subpopulation with high ceftazidime/avibactam resistance for BOT-EMO KPC-Kp showed low carbapenem MICs, whereas a subpopulation with high meropenem resistance had a low MIC of ceftazidime/avibactam. Conclusions: Our analysis indicates that mixed subpopulations of ceftazidime/avibactam-resistant KPC-Kp emerge after ceftazidime/avibactam treatment. The evolution of different subpopulations that are highly resistant to ceftazidime/avibactam likely contributes to treatment failure, thereby highlighting the need for combination treatment strategies to limit selection of ceftazidime/avibactam-resistant KPC-Kp subpopulations.

Risk factors for recurrent carbapenem resistant Klebsiella pneumoniae bloodstream infection: a prospective cohort study.

To assess risk factors for recurrent carbapenem-resistant Klebsiella pneumoniae bloodstream-infection (CR-KP BSI), we performed a prospective observational cohort study of all consecutive adult patients cured of a CR-KP BSI at our hospital over a six-year period (June 2010 to June 2016). Maximum follow-up per patient was 180 days from the index blood cultures (BCs). Recurrent CR-KP BSI was defined as new evidence of positive BCs in patients with documented clinical response after completing a course of anti-CR-KP therapy. Univariate and multivariate cause-specific Cox proportional hazards analysis were performed. During the study period 249 patients were diagnosed with a CR-KP BSI, 193 were deemed as cured within 14 days after index BCs and were analysed. Recurrence occurred in 32/193 patients (16.6%) within a median of 35 (IQR 25-45) days after index BCs. All but one of the recurrences occurred within 60 days after the index BCs. Comparison of recurrent and non-recurrent cases showed significant differences for colistin use (84.4% vs. 62.2%, p = 0.01), meropenem-colistin-tigecycline regimen (43.8% vs. 24.8%, p = 0.03) and length of therapy for the index BSI episode (median 18 vs. 14 days, p = 0.004). All-cause 180-day mortality (34.4% vs. 16.1%, p = 0.02) was higher in recurrent cases. In the multivariate analysis, the only independent variable was source control as a protective factor for recurrence. Recurrence is frequent among patients cured of a CR-KP BSI and is associated with higher long-term mortality. When feasible, source control is mandatory to avoid recurrence. The role of antibiotic treatment should be further investigated in large multicentre studies.

Infectious Diseases Team for the Early Management of Severe Sepsis and Septic Shock in the Emergency Department.

Background: The impact on patient survival of an infectious disease (ID) team dedicated to the early management of severe sepsis/septic shock (SS/SS) in Emergency Department (ED) has yet to be assessed. Methods: A quasiexperimental pre-post study was performed at the general ED of our hospital. During the pre phase (June 2013-July 2014), all consecutive adult patients with SS/SS were managed according to the standard of care, data were prospectively collected. During the post phase (August 2014-October 2015), patients were managed in collaboration with a dedicated ID team performing a bedside patient evaluation within 1 hour of ED arrival. Results: Overall, 382 patients were included, 195 in the pre phase and 187 in the post phase. Median age was 82 years (interquartile range, 70-88). The most common infection sources were lung (43%) and urinary tract (17%); in 22% of cases, infection source remained unknown. During the post phase, overall compliance with the Surviving Sepsis Campaign (SSC) bundle and appropriateness of initial antibiotic therapy improved from 4.6% to 32% (P < .001) and from 30% to 79% (P < .001), respectively. Multivariate analysis showed that predictors of all-cause 14-day mortality were quick sepsis-related organ failure assessment ≥2 (hazard ratio [HR], 1.68; 95% confidence interval [CI], 1.15-2.45; P = .007), serum lactate ≥2 mmol/L (HR, 2.13; 95% CI, 1.39-3.25; P < .001), and unknown infection source (HR, 2.07; 95% CI, 1.42-3.02; P < .001); being attended during the post phase was a protective factor (HR, 0.64; 95% CI, 0.43-0.94; P = .026). Conclusion: Implementation of an ID team for the early management of SS/SS in the ED improved the adherence to SSC recommendations and patient survival.

Leukocyte presence does not increase microbicidal activity of Platelet-rich Plasma in vitro.

BACKGROUND: Human platelets are a rich reservoir of molecules that promote regenerative processes and microbicidal activity. This activity might be increased by concentration in platelet-rich plasma (PRP) products and modulated by the presence of leukocytes. Despite extensive use in clinical procedures, only few studies have investigated PRP's real microbicidal potential. Therefore, this study aimed at comparing the in vitro microbicidal activity of platelets and leukocyte-enriched PRP (L-PRP) to pure platelet-rich plasma (P-PRP) and the contribution of leukocytes to microbicidal properties. Antimicrobial effects of P- and L-PRP were tested against Escherichia Coli, Staphylococcus Aureus, Klebsiella Pneumoniae, Pseudomonas Aeruginosa and Enterococcus Faecalis. Furthermore, L-PRP was frozen (L-PRP cryo) to assess whether the preparation maintained in vitro characteristics. Microbicidal proteins released by the three preparations were also evaluated. RESULTS: L-PRP, L-PRP cryo and P-PRP generally induced comparable bacterial growth inhibition for up to 4 h' incubation, range 1-4 log. MIP-1α, RANTES, GRO-α, IL-8, NAP-2, SDF-1α and IL-6 showed strong microbicidal potential. CONCLUSIONS: We found in vitro antibacterial activity of L-PRP and P-PRP and the possibility to cryopreserve L-PRP, without important changes to its effectiveness; similar microbicidal activity between preparations containing or not leukocytes; and the contribution of three new molecules (NAP-2, SDF-1α and IL-6).

Platelet-rich plasma affects bacterial growth in vitro.

BACKGROUND AIMS: Platelet-rich plasma (PRP), a blood derivative rich in platelets, is a relatively new technique used in tissue regeneration and engineering. The increased quantity of platelets makes this formulation of considerable value for their role in tissue healing and microbicidal activity. This activity was investigated against five of the most important strains involved in nosocomial infections (Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae and Streptococcus faecalis) to understand the prophylactic role of pure (P)-PRP. Microbicidal proteins released from activated P-PRP platelets were also determined. METHODS: The microbicidal activity of P-PRP and platelet-poor plasma (PPP) was evaluated on different concentrations of the five bacterial strains incubated for 1, 2, 4 and 18 h and plated on agar for 18-24 h. P-PRP and PPP-released microbicidal proteins were evaluated by means of multiplex bead-based immunoassays. RESULTS: P-PRP and PPP inhibited bacterial growth for up to 2 h of incubation. The effect of P-PRP was significantly higher than that of PPP, mainly at the low seeding concentrations and/or shorter incubation times, depending on the bacterial strain. Chemokine (C-C motif) ligand-3, chemokine (C-C motif) ligand-5 and chemokine (C-X-C motif) ligand-1 were the molecules mostly related to Pseudomonas aeruginosa, Staphylococcus aureus and Streptococcus faecalis inhibition. Escherichia coli and Klebsiella pneumoniae were less influenced. CONCLUSIONS: The present results show that P-PRP might supply an early protection against bacterial contaminations during surgical interventions because the inhibitory activity is already evident from the first hour of treatment, which suggests that physiological molecules supplied in loco might be important in the time frame needed for the activation of the innate immune response.

Outbreak of Citrobacter freundii carrying VIM-1 in an Italian Hospital, identified during the carbapenemases screening actions, June 2012.

OBJECTIVE: The identification of patients colonized or infected with carbapenemase-producing Enterobacteriaceae (CPE), in order to control and prevent the global spread of multidrug-resistant (MDR) pathogens. METHODS: From June 1 to June 15, 2012, eight Citrobacter freundii strains with reduced susceptibility to carbapenems were isolated from rectal swabs of hospitalized patients during active screening following the detection of a Klebsiella pneumoniae carbapenemase (KPC) -positive patient on the ward. All isolates were analyzed phenotypically and molecularly by PCR and sequencing. Genotype clustering was performed by multilocus sequence typing (MLST) analysis. RESULTS: The isolates showed high rates of multidrug resistance profile. A phenotypic assay for carbapenemase production suggested the presence of metallo-ß-lactamase (MBL). The blaVIM-1 gene was detected in all imipenem-resistant C. freundii isolates. MLST showed that the C. freundii isolates shared the same sequence type (ST). Phylogenetic analysis revealed a strict relationship with an ST5C. freundii isolate from a diarrhea patient in China. CONCLUSIONS: Our findings showed that the active surveillance program for CPE was useful, not only for the detection of KPC-producers, but also to identify and control the spread of other MDR pathogens that could expand the spectrum of circulating MDR pathogens.

Evaluation of phenotypic and genotypic approaches for the detection of class A and class B carbapenemases in Enterobacteriaceae.

The spread of carbapenemases in Enterobacteriaceae is among the most important issues in the antimicrobial resistance. The rapid and recent diffusion of class A and B carbapenemases determined the need of specific diagnostic tests able to detect with high sensitivity this type of resistance and to discriminate between the different enzymes. The aim of this study was to test two carbapenemase detection assays, the Rosco Synergic and the Hyplex polymerase chain reaction-enzyme-linked immunosorbent assays for screening carbapenemase-producing Enterobacteriaceae. The phenotypic and genotypic tests were evaluated among 108 clinical isolates, including Klebsiella pneumoniae carbapenemase (KPC) (n=50) and metallo-ß-lactamase- (MBL) (n=20), and AmpC- (n=10) producing Enterobacteriaceae. The commercial phenotypic assay showed a high sensitivity performance detecting all KPC and MBL producers, including New Delhi MBL 1 (NDM-1) strains. In addition, the Rosco Synergic assay was able to distinguish specifically between the different mechanisms that confer resistance to carbapenems in Enterobacteriaceae. We also demonstrated that the genotypic test was able to detect all the class A and B carbapenemases showing high sensitivity (100%) and specificity (98%) in a fast and reliable time. Based on these results, both the commercial phenotypic and the genotypic assays could be helpful as confirmatory and discriminatory tests for the detection of class A and class B carbapenemases.

Amiodarone-related pneumonitis and peripheral neuropathy in an elderly patient.

Amiodarone, which has been used since 1967 as an antiarrhythmic drug, gives rise to a variety of cardiac and extracardiac adverse side-effects. Among these, pulmonary toxicity is considered the most frequent and serious extracardiac side-effect, since it may occur in various atypical forms and often limits the drug's clinical use. We encountered a 67-year-old white male patient with suspected amiodarone pneumonitis characterized by multiple lung nodules associated with pleural and pericardial effusion and peripheral neuropathy. Because differential diagnosis with pulmonary infectious diseases may be extremely difficult, the attending physician should therefore bear in mind the possibility of amiodarone pneumonitis whenever the drug is given.