Procalcitonin and C-reactive protein to rule out early bacterial coinfection in COVID-19 critically ill patients.

PURPOSE: Although the prevalence of community-acquired respiratory bacterial coinfection upon hospital admission in patients with coronavirus disease 2019 (COVID-19) has been reported to be < 5%, almost three-quarters of patients received antibiotics. We aim to investigate whether procalcitonin (PCT) or C-reactive protein (CRP) upon admission could be helpful biomarkers to identify bacterial coinfection among patients with COVID-19 pneumonia. METHODS: We carried out a multicentre, observational cohort study including consecutive COVID-19 patients admitted to 55 Spanish intensive care units (ICUs). The primary outcome was to explore whether PCT or CRP serum levels upon hospital admission could predict bacterial coinfection among patients with COVID-19 pneumonia. The secondary outcome was the evaluation of their association with mortality. We also conducted subgroups analyses in higher risk profile populations. RESULTS: Between 5 February 2020 and 21 December 2021, 4076 patients were included, 133 (3%) of whom presented bacterial coinfection. PCT and CRP had low area under curve (AUC) scores at the receiver operating characteristic (ROC) curve analysis [0.57 (95% confidence interval (CI) 0.51-0.61) and 0.6 (95% CI, 0.55-0.64), respectively], but high negative predictive values (NPV) [97.5% (95% CI 96.5-98.5) and 98.2% (95% CI 97.5-98.9) for PCT and CRP, respectively]. CRP alone was associated with bacterial coinfection (OR 2, 95% CI 1.25-3.19; p = 0.004). The overall 15, 30 and 90 days mortality had a higher trend in the bacterial coinfection group, but without significant difference. PCT ≥ 0.12 ng/mL was associated with higher 90 days mortality. CONCLUSION: Our study suggests that measurements of PCT and CRP, alone and at a single time point, are not useful for ruling in or out bacterial coinfection in viral pneumonia by COVID-19.

Multiplex protein profiling of bronchial aspirates reveals disease-, mortality- and respiratory sequelae-associated signatures in critically ill patients with ARDS secondary to SARS-CoV-2 infection.

Introduction: Bronchial aspirates (BAS) obtained during invasive mechanical ventilation (IMV) constitutes a useful tool for molecular phenotyping and decision making. Aim: To identify the proteomic determinants associated with disease pathogenesis, all-cause mortality and respiratory sequelae in BAS samples from critically ill patients with SARS-CoV-2-induced ARDS. Methods: Multicenter study including 74 critically ill patients with COVID-19 and non-COVID-19 ARDS. BAS were obtained by bronchoaspiration after IMV initiation. Three hundred sixty-four proteins were quantified using proximity extension assay (PEA) technology. Random forest models were used to assess predictor importance. Results: After adjusting for confounding factors, CST5, NADK, SRPK2 and TGF-α were differentially detected in COVID-19 and non-COVID-19 patients. In random forest models for COVID-19, CST5, DPP7, NADK, KYAT1 and TYMP showed the highest variable importance. In COVID-19 patients, reduced levels of ENTPD2 and PTN were observed in nonsurvivors of ICU stay, even after adjustment. AGR2, NQO2, IL-1α, OSM and TRAIL showed the strongest associations with in-ICU mortality and were used to construct a protein-based prediction model. Kaplan-Meier curves revealed a clear separation in mortality risk between subgroups of PTN, ENTPD2 and the prediction model. Cox regression models supported these findings. In survivors, the levels of FCRL1, NTF4 and THOP1 in BAS samples obtained during the ICU stay correlated with lung function (i.e., DLCO levels) 3 months after hospital discharge. Similarly, Flt3L and THOP1 levels were correlated with radiological features (i.e., TSS). These proteins are expressed in immune and nonimmune lung cells. Poor host response to viral infectivity and an inappropriate reparative mechanism seem to be linked with the pathogenesis of the disease and fatal outcomes, respectively. Conclusion: BAS proteomics identified novel factors associated with the pathology of SARS-CoV-2-induced ARDS and its adverse outcomes. BAS-based protein testing emerges as a novel tool for risk assessment in the ICU.

Resistance mechanisms and molecular epidemiology of Pseudomonas aeruginosa strains from patients with bronchiectasis.

BACKGROUND: Non-cystic fibrosis bronchiectasis (BE) is a chronic structural lung condition that facilitates chronic colonization by different microorganisms and courses with recurrent respiratory infections and frequent exacerbations. One of the main pathogens involved in BE is Pseudomonas aeruginosa. OBJECTIVES: To determine the molecular mechanisms of resistance and the molecular epidemiology of P. aeruginosa strains isolated from patients with BE. METHODS: A total of 43 strains of P. aeruginosa were isolated from the sputum of BE patients. Susceptibility to the following antimicrobials was analysed: ciprofloxacin, meropenem, imipenem, amikacin, tobramycin, aztreonam, piperacillin/tazobactam, ceftazidime, ceftazidime/avibactam, ceftolozane/tazobactam, cefepime and colistin. The resistance mechanisms present in each strain were assessed by PCR, sequencing and quantitative RT-PCR. Molecular epidemiology was determined by MLST. Phylogenetic analysis was carried out using the eBURST algorithm. RESULTS: High levels of resistance to ciprofloxacin (44.19%) were found. Mutations in the gyrA, gyrB, parC and parE genes were detected in ciprofloxacin-resistant P. aeruginosa strains. The number of mutated QRDR genes was related to increased MIC. Different ß-lactamases were detected: blaOXA50, blaGES-2, blaIMI-2 and blaGIM-1. The aac(3)-Ia, aac(3)-Ic, aac(6″)-Ib and ant(2″)-Ia genes were associated with aminoglycoside-resistant strains. The gene expression analysis showed overproduction of the MexAB-OprM efflux system (46.5%) over the other efflux system. The most frequently detected clones were ST619, ST676, ST532 and ST109. CONCLUSIONS: Resistance to first-line antimicrobials recommended in BE guidelines could threaten the treatment of BE and the eradication of P. aeruginosa, contributing to chronic infection.

Cardiovascular Events During and After Bronchiectasis Exacerbations and Long-term Mortality.

BACKGROUND: Population-based and retrospective studies have shown that risk for cardiovascular events such as arrythmias, ischemic episodes, or heart failure, increase during and after bronchiectasis exacerbations. RESEARCH QUESTION: What are the risk factors for cardiovascular events (CVE) during and after bronchiectasis exacerbations and their impact on mortality? STUDY DESIGN AND METHODS: This was a post hoc retrospective analysis of a prospective observational study of 250 patients with bronchiectasis at two tertiary care hospitals. Only the first exacerbation was considered for each patient, collecting demographic, comorbidity, and severity data. The main outcomes were the appearance of CVE and mortality. Risk factors for CVE were analyzed using a semi-competing risks model. RESULTS: During a median follow-up of 35 months, 74 (29.6%) patients had a CVE and 93 (37.2%) died. Semi-competing risk analysis indicated that age, arterial hypertension, COPD, and potentially severe exacerbations significantly increased the risk for developing CVE. Compared with patients without CVE, those with CVE had higher mortality. INTERPRETATION: Demographic factors and comorbidities are risk factors for the development of CVE after an acute exacerbation of bronchiectasis. The appearance of CVE worsens long-term prognosis.

Pseudomonas aeruginosa in Bronchiectasis.

Pseudomonas aeruginosa (PA) in patients with bronchiectasis (BE) is associated with a poor outcome and quality of life, and its presence is considered a marker of disease severity. This opportunistic pathogen is known for its ability to produce biofilms on biotic or abiotic surfaces and to survive environmental stress exerted by antimicrobials, inflammation, and nutrient or oxygen depletion. The presence of PA biofilms has been linked to chronic respiratory infection in cystic fibrosis but not in BE. There is considerable inconsistency in the reported infection/eradication rates of PA and chronic PA. In addition, inadequate antimicrobial treatment may potentiate the progression from intermittent to chronic infection and also the emergence of antibiotic resistance. A better comprehension of the pathophysiology of PA infections and its implications for BE is urgently needed. This can drive improvements in diagnostic accuracy, can move us toward a new consensus definition of chronic infection, can better define the follow-up of patients at risk of PA, and can achieve more successful eradication rates. In addition, the new technological advances regarding molecular diagnostics, -omics, and biomarkers require us to reconsider our traditional concepts.

Aetiological diagnosis in new adult outpatients with bronchiectasis:role of predictors derived from real life experience.

BACKGROUND: In adult patients with bronchiectasis (BE) the identification of the underlying aetiology may be difficult. In a new patient with BE the performance of a panel of tests is recommended, even though this practice may be expensive and the level of evidence supporting is low. We aimed to identify a panel of variables able to predict the aetiological diagnosis of BE. METHODS: Our prospective study derived from our real-life experience on the management of adult stable BE outpatients. We recorded variables concerning clinical, radiological, microbiological and laboratory features. We identified five groups of aetiological diagnosis of BE (idiopathic, post-infective, COPD, asthma and non-common diseases [immunodeficiency or other rare conditions]). Multivariate models were used to identify predictors of each aetiological diagnosis. The suitability of performing a specific test for the diagnosis was also considered. RESULTS: We enrolled 354 patients with a new diagnosis of BE. Patients with different aetiological causes differed significantly with regard to age, sex, smoking habit, comorbidities, dyspnoea perception, airflow obstruction and severity scores. Various predictors were assessed, including sex, previous respiratory infections, diffuse localization of BE, risk scores, and laboratory variables (sodium and eosinophils). The levels of autoantibodies or immunoglobulins were reserved for the diagnosis of non-common disease. CONCLUSION: Our research confirms that some predictors are specific for the aetiological diagnosis of BE. The possibility of integrating this information may represent a useful tool for the diagnosis. The execution of certain specific tests should be reserved for patients with a non-common disease.

Systemic Inflammation during and after Bronchiectasis Exacerbations: Impact of Pseudomonas aeruginosa.

Bronchiectasis is a chronic structural disease associated with exacerbations that provoke systemic inflammation. We aimed to evaluate the systemic acute proinflammatory cytokine and its biomarker profiles during and after exacerbations and its relationship with the severity of episode, microbiological findings, and the bronchiectasis severity index. This prospective observational study compared exacerbation and stable groups. Cytokine (interleukins (IL)-17a, IL-1ß, IL-6, IL 8; tumor necrosis factor-alpha (α)) and high-sensitivity C-reactive protein (hsCRP) levels were determined by multiplex analysis on days 1, 5, 30, and 60 in the exacerbation group and on day 1 in the stable group. We recruited 165 patients with exacerbations, of which 93 were severe (hospitalized). Proinflammatory systemic IL-17a, IL-1ß, IL-8, and tumor necrosis factor-α levels increased similarly on days 1 and 5 in severe and non-severe episodes, but on day 30, IL-17a, IL-8, and IL-6 levels were only increased for severe exacerbations. The highest IL-17a level occurred in patients with chronic plus the acute isolation of Pseudomonas aeruginosa. At 30 days, severe exacerbations were independently associated with higher levels of IL-17 (Odds ratio (OR) 4.58), IL-6 (OR 4.89), IL-8 (OR 3.08), and hsCRP (OR 6.7), adjusted for age, the bronchiectasis severity index, and treatment duration. Exacerbations in patients with chronic P. aeruginosa infection were associated with an increase in IL-17 and IL-6 at 30 days (ORs 7.47 and 3.44, respectively). Severe exacerbations elicit a higher systemic proinflammatory response that is sustained to day 30. Patients with chronic P. aeruginosa infection had impaired IL-17a reduction. IL-17a could be a useful target for measuring systemic inflammation.

Association between physical activity and risk of hospitalisation in bronchiectasis.

BACKGROUND: Patients with bronchiectasis have a less active lifestyle than healthy peers, but the association with hospital admission has not been explored. The aim of this study was to investigate the association between 1) any physical activity variable; and 2) sedentary time, with hospitalisation due to exacerbation in adults with bronchiectasis. METHODS: In this prospective observational study, baseline lung function, quality of life, exercise tolerance, severity of bronchiectasis and physical activity were recorded. Physical activity was objectively assessed over a week using a SenseWear armband and the results were expressed in steps·day-1 and sedentary time. Number of hospitalisations due to a bronchiectasis exacerbation and time to first event were recorded after 1-year follow-up. RESULTS: Sixty-four patients with bronchiectasis were analysed, of whom 15 (23%) were hospitalised during the follow-up. Hospitalised patients showed poor baseline clinical and severity outcomes, fewer steps walked per day and more sedentary behaviour than the non-hospitalised group. Patients who walked ≤6290 steps·day-1 or spent ≥7.8 h·day-1 in sedentary behaviour had an increased risk of hospital admission due to bronchiectasis exacerbation at 1-year follow-up. Specifically, ≥7.8 h·day-1 of sedentary behaviour was associated with a 5.9-fold higher risk of hospital admission in the following year. CONCLUSIONS: Low levels of physical activity and high sedentary time at baseline were associated with a higher risk of hospitalisation due to bronchiectasis exacerbation. If these findings are validated in future studies, it might be appropriate to include physical activity and sedentary behaviour as an item in severity scores.

Mucoid Pseudomonas aeruginosa alters sputum viscoelasticity in patients with non-cystic fibrosis bronchiectasis.

INTRODUCTION AND AIM: Pseudomonas aeruginosa could acquire a mucoid phenotype due to mutations in mucA (mucoid Pseudomonas aeruginosa - mPA) that is a hallmark of poor prognosis in patients with bronchiectasis. Despite the higher prevalence of Pseudomonas aeruginosa in bronchiectasis, how mPA and non-mucoid Pseudomonas aeruginosa (non-mPA) phenotypes could affect viscoelastic properties of sputum is unknown. Our aim was to determine the relationship between Pseudomonas aeruginosa phenotypes isolation, the viscoelastic properties of sputum and the clinical outcomes in patients with bronchiectasis. METHODS: A cross-sectional study was conducted of sputum samples obtained by spontaneous expectoration and sent for microbiology and rheology analysis. Elasticity and viscosity were measured at two oscillatory frequencies (1 and 100 rad/s). Socio-demographic and clinical data were recorded. RESULTS: We analyzed 17 patients with mPA, 14 with non-mPA and 17 with no organism reported (NOR). Compared with the NOR group, the mPA group showed higher elasticity (median 10.30 vs. 5.70, p = 0.023), viscosity (2.40 vs. 1.50, p = 0.039), and stiffness (10.70 vs. 6.00, p = 0.024). Values in the mPA group tended to be higher compared with non-mPA. Clinically, the mPA group showed greater hospitalizations during the previous year and greater affected lobes than the non-mPA and NOR groups. CONCLUSIONS: The mPA phenotype is associated with increased elasticity, viscosity and stiffness of bronchiectatic sputum. Viscoelastic properties could be used as a marker of poor mucociliary clearance in mPA, with potentially important clinical implications.

Factors associated with hospitalization in bronchiectasis exacerbations: a one-year follow-up study.

BACKGROUND: Bronchiectasis (BE) is a chronic structural lung disease with frequent exacerbations, some of which require hospital admission though no clear associated factors have been identified. We aimed to evaluate factors associated with hospitalization due to exacerbations during a 1-year follow-up period. METHODS: A prospective observational study was performed in patients recruited from specialized BE clinics. We considered all exacerbations diagnosed and treated with antibiotics during a follow-up period of 1 year. The protocol recorded baseline variables, usual treatments, Bronchiectasis Severity Index (BSI) and FACED scores, comorbid conditions and prior hospitalizations. RESULTS: Two hundred and 65 patients were recruited, of whom 162 required hospital admission during the follow-up period. Independent risk factors for hospital admission were age, previous hospitalization due to BE, use of proton pump inhibitors, heart failure, FACED and BSI, whereas pneumococcal vaccination was a protective factor. The area under the receiver operator characteristic curve (AUC) was 0.799 for BSI model was 0.799, and 0.813 for FACED model. CONCLUSIONS: Previous hospitalization, use of proton pump inhibitors, heart failure along with BSI or FACED scores is associated factors for developing exacerbations that require hospitalization. Pneumococcal vaccination was protective. This information may be useful for the design of preventive strategies and more intensive follow-up plans.

Risk factors for multidrug-resistant pathogens in bronchiectasis exacerbations.

BACKGROUND: Non-cystic fibrosis bronchiectasis is a chronic structural lung condition that courses with recurrent infectious exacerbations that lead to frequent antibiotic treatment making this population more susceptible to acquire pathogens with antibiotic resistance. We aimed to investigate risk factors associated with isolation of multidrug-resistant pathogens in bronchiectasis exacerbations. METHODS: A prospective observational study was conducted in two tertiary-care hospitals, enrolling patients when first exacerbation appeared. Multidrug-resistance was determined according to European Centre of Diseases Prevention and Control classification. RESULTS: Two hundred thirty three exacerbations were included and microorganisms were isolated in 159 episodes. Multidrug-resistant pathogens were found in 20.1% episodes: Pseudomonas aeruginosa (48.5%), methicillin-resistant Staphylococcus aureus (18.2%) and Extended spectrum betalactamase + Enterobacteriaceae (6.1%), and they were more frequent in exacerbations requiring hospitalization (24.5% vs. 10.2%, p: 0.016). Three independent multidrug-resistant risk factors were found: chronic renal disease (Odds ratio (OR), 7.60, 95% CI 1.92-30.09), hospitalization in the previous year (OR, 3.88 95% CI 1.37-11.02) and prior multidrug-resistant isolation (OR, 5.58, 95% CI 2.02-15.46). The proportion of multidrug-resistant in the 233 exacerbations was as follows: 3.9% in patients without risk factors, 12.6% in those with 1 factor and 53.6% if ≥2 risk factors. CONCLUSIONS: Hospitalization in the previous year, chronic renal disease, and prior multidrug-resistant isolation are risk factors for identification multidrug-resistant pathogens in exacerbations. This information may assist clinicians in choosing empirical antibiotics in daily clinical practice.

Intensive care unit-acquired pneumonia due to Pseudomonas aeruginosa with and without multidrug resistance.

OBJECTIVE: Pseudomonas aeruginosa often presents multi-drug resistance (MDR) in intensive care unit (ICU)-acquired pneumonia (ICUAP), possibly resulting in inappropriate empiric treatment and worse outcomes. We aimed to identify patients with ICUAP at risk for these pathogens in order to improve treatment selection and outcomes. METHODS: We prospectively assessed 222 consecutive immunocompetent ICUAP patients confirmed microbiologically. We determined the characteristics, risk factors, systemic inflammatory response and outcomes of P. aeruginosa pneumonia (Pa-ICUAP), compared to other aetiologies. We also compared patients with MDR vs. non-MDR Pa-ICUAP. RESULTS: Pseudomonas aeruginosa was the most frequent aetiology (64, 29%); 22 (34%) cases had MDR. Independent predictors for Pa-ICUAP were prior airway colonization by P. aeruginosa, previous antibiotic treatment, solid cancer and shock; alcohol abuse and pleural effusion were independently associated to lower risk for Pa-ICUAP. Chronic liver disease independently predicted MDR among Pa-ICUAP. The inflammatory biomarkers were similar between all groups. Patients with Pa-ICUAP had lower unadjusted 90-day survival (p = 0.049). However, the 90-day survival adjusted for confounding factors using a propensity score did not differ between all groups. CONCLUSION: Pseudomonas aeruginosa remains the most frequent aetiology of ICUAP, with high prevalence of MDR. These risk factors should be taken into account to avoid inappropriate empiric antibiotics for Pa-ICUAP. Pseudomonas aeruginosa, regardless multidrug resistance, was not associated with different propensity-adjusted survival.

Phenotypic shift in Pseudomonas aeruginosa populations from cystic fibrosis lungs after 2-week antipseudomonal treatment.

BACKGROUND: The influence of suppressive therapy on the different P. aeruginosa phenotypes harbored in the lungs of cystic fibrosis (CF) patients remains unclear. Our aim was to investigate the phenotypic changes (mucoidy, hypermutability, antibiotic resistance, transcriptomic profiles and biofilm) in P. aeruginosa populations before and after a 2-week course of suppressive antimicrobial therapy in chronically infected CF patients in Denmark. MATERIAL AND METHODS: Prospective observational clinical study. Sputum samples were assessed before and after treatment for P. aeruginosa, with regard to: a) colony-forming units (CFU/mL), b) frequency of mucoids and non-mucoids, c) resistance pattern to anti-pseudomonal drugs, d) hypermutability, e) transcriptomic profiles, and f) presence of biofilms. RESULTS: We collected 23 sputum samples (12 before antibiotic treatment and 11 after) and 77 P. aeruginosa from different CF patients. After treatment, the P. aeruginosa burden diminished but antimicrobial resistance to aztreonam, tobramycin and ceftazidime rose; non-mucoid phenotypes presented increased resistance to colistin, tobramycin, meropenem, and ciprofloxacin, and hypermutable phenotypes to ciprofloxacin. In spite of biofilm persistence, a down-regulation of genes involved in denitrification was detected. CONCLUSION: A 2-week course of suppressive therapy reduces P. aeruginosa lung colonization and influences nitrogen metabolism genes, but also promotes antimicrobial resistance while P. aeruginosa persists in biofilms.