Proteomic analysis from skin swabs reveals a new set of proteins identifying skin impairment in atopic dermatitis.

Atopic Dermatitis (AD) is a common inflammatory skin disease characterized by skin and systemic inflammation, and barrier dysfunction. Herein, we investigate the proteomic profile of AD skin barrier to identify a unique signature with an easy-performed sampling approach. We enrolled 8 moderate-to-severe AD patients and 8 age- and gender-matched healthy controls. Swabs were obtained from non-lesional skin of retroauricular area and antecubital fold. Peptide mixtures obtained through protein precipitation and in-solution digestion were analysed using NanoLC-MS/MS. Label-free quantification and statistical analysis were conducted in MaxQuant and Perseus. Bioinformatics analysis was performed using Gene Ontology and STRING. We identified 908 proteins and 35 differentially expressed proteins were selected (fold change 2, FDR < 0.05). Particularly, AD skin showed downregulation of skin hydration factors, structural and epidermal proteins, abnormalities in protease-proteasome complex and lipid metabolism profile. Imbalance of antioxidant and inflammatory processes, along with TDRD15 upregulation was also observed. Our result showed partial overlap with skin biopsy/tape-strips studies, showing the reliability of our sampling approach which could be an easier method of detection of hallmark barrier proteins in AD. Furthermore, we displayed a new differentially expressed set of proteins, not yet explored in AD which can have a potential role in AD pathomechanisms.

Vasculitis changes in COVID-19 survivors with persistent symptoms: an [18F]FDG-PET/CT study.

PURPOSE: Several patients experience unexplained persistent symptoms after SARS-CoV-2 recovering. We aimed at evaluating if 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) was able to demonstrate a persistent inflammatory process. METHODS: Recovered adult COVID-19 patients, who complained unexplained persisting symptoms for more than 30 days during the follow-up visits, were invited to participate in the study. Patients fulfilling inclusion criteria were imaged by [18F]FDG positron emission tomography/computed tomography ([18F]FDG-PET/CT). Whole-body [18F]FDG-PET/CT, performed according to good clinical practice, was qualitatively (comparison with background/liver) and semi-quantitatively (target-to-blood pool ratio calculated as average SUVmax artery/average SUVmean inferior vena cava) analyzed. Negative follow-up [18F]FDG-PET/CT images of oncologic patients matched for age/sex served as controls. Mann-Whitney test was used to test differences between groups. SPSS version 26 was used for analyses. RESULTS: Ten recovered SARS-CoV-2 patients (seven male and three females, median age 52 years, range 46-80) with persisting symptoms were enrolled in the study. Common findings at visual analysis were increased [18F]FDG uptake in bone marrow and blood vessels (8/10 and 6/10 cases, respectively). [18F]FDG uptake in bone marrow did not differ between cases and controls (p = 0.16). The total vascular score was similar in the two groups (p = 0.95). The target-to-blood pool ratio resulted higher in recovered SARS-CoV-2 patients than in controls. CONCLUSION: Although the total vascular score was similar in the two groups, the target-to-blood pool ratio was significantly higher in three vascular regions (thoracic aorta, right iliac artery, and femoral arteries) in the recovered COVID-19 cohort than in controls, suggesting that SARS-CoV-2 induces vascular inflammation, which may be responsible for persisting symptoms.

Long COVID hallmarks on [18F]FDG-PET/CT: a case-control study.

PURPOSE: The present study hypothesised that whole-body [18F]FDG-PET/CT might provide insight into the pathophysiology of long COVID. METHODS: We prospectively enrolled 13 adult long COVID patients who complained for at least one persistent symptom for >30 days after infection recovery. A group of 26 melanoma patients with negative PET/CT matched for sex/age was used as controls (2:1 control to case ratio). Qualitative and semi-quantitative analysis of whole-body images was performed. Fisher exact and Mann-Whitney tests were applied to test differences between the two groups. Voxel-based analysis was performed to compare brain metabolism in cases and controls. Cases were further grouped according to prevalent symptoms and analysed accordingly. RESULTS: In 4/13 long COVID patients, CT images showed lung abnormalities presenting mild [18F]FDG uptake. Many healthy organs/parenchyma SUVs and SUV ratios significantly differed between the two groups (p ≤ 0.05). Long COVID patients exhibited brain hypometabolism in the right parahippocampal gyrus and thalamus (uncorrected p < 0.001 at voxel level). Specific area(s) of hypometabolism characterised patients with persistent anosmia/ageusia, fatigue, and vascular uptake (uncorrected p < 0.005 at voxel level). CONCLUSION: [18F]FDG PET/CT acknowledged the multi-organ nature of long COVID, supporting the hypothesis of underlying systemic inflammation. Whole-body images showed increased [18F]FDG uptake in several "target" and "non-target" tissues. We found a typical pattern of brain hypometabolism associated with persistent complaints at the PET time, suggesting a different temporal sequence for brain and whole-body inflammatory changes. This evidence underlined the potential value of whole-body [18F]FDG PET in disclosing the pathophysiology of long COVID.

Neuromonitoring of delirium with quantitative pupillometry in sedated mechanically ventilated critically ill patients.

BACKGROUND: Intensive care unit (ICU) delirium is a frequent secondary neurological complication in critically ill patients undergoing prolonged mechanical ventilation. Quantitative pupillometry is an emerging modality for the neuromonitoring of primary acute brain injury, but its potential utility in patients at risk of ICU delirium is unknown. METHODS: This was an observational cohort study of medical-surgical ICU patients, without acute or known primary brain injury, who underwent sedation and mechanical ventilation for at least 48 h. Starting at day 3, automated infrared pupillometry-blinded to ICU caregivers-was used for repeated measurement of the pupillary function, including quantitative pupillary light reflex (q-PLR, expressed as % pupil constriction to a standardized light stimulus) and constriction velocity (CV, mm/s). The relationship between delirium, using the CAM-ICU score, and quantitative pupillary variables was examined. RESULTS: A total of 59/100 patients had ICU delirium, diagnosed at a median 8 (5-13) days from admission. Compared to non-delirious patients, subjects with ICU delirium had lower values of q-PLR (25 [19-31] vs. 20 [15-28] %) and CV (2.5 [1.7-2.8] vs. 1.7 [1.4-2.4] mm/s) at day 3, and at all additional time-points tested (p < 0.05). After adjusting for the SOFA score and the cumulative dose of analgesia and sedation, lower q-PLR was associated with an increased risk of ICU delirium (OR 1.057 [1.007-1.113] at day 3; p = 0.03). CONCLUSIONS: Sustained abnormalities of quantitative pupillary variables at the early ICU phase correlate with delirium and precede clinical diagnosis by a median 5 days. These findings suggest a potential utility of quantitative pupillometry in sedated mechanically ventilated ICU patients at high risk of delirium.

Cytokine Pathways and Investigational Target Therapies in Hidradenitis Suppurativa.

BACKGROUND: Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease affecting areas with a high density of apocrine glands and characterized by subcutaneous nodules that may evolve into fistulas with pus secretion. METHODS: The aim of this review is to investigate all current knowledge on cytokine regulation in the pathogenesis of HS. A systematic literature research using the words "cytokine", "interleukin", "pathway", and "hidradenitis suppurativa" was performed in PubMed/Medline and Scopus/Embase databases. A search of the clinicaltrials.gov website for interventional recruiting and completed trials including the term "hidradenitis suppurativa" was also performed up to August 2020. We will discuss the pathogenetic role of various cytokines in HS and potential therapeutic targets for this debilitating disease. RESULTS: The pathophysiology underlying this complex condition has not been clearly defined. An upregulation of various cytokines, such as tumor necrosis factor alpha (TNF-α), interleukin (IL)-1, IL-17, IL-23, and other molecules seems to be related to this inflammatory condition. Various cells, such as lymphocytes T Helper 1 and 17 and keratinocytes seem to be involved in the genesis of this condition. CONCLUSIONS: Several future studies and clinical trials are necessary in order to have new knowledge about HS and to properly treat this complex condition.

Protocolized Brain Oxygen Optimization in Subarachnoid Hemorrhage.

BACKGROUND: Brain tissue hypoxia (PbtO2 < 20 mmHg) is common after subarachnoid hemorrhage (SAH) and associated with poor outcome. Recent data suggest that brain oxygen optimization is feasible and reduces the time spent with PbtO2 < 20 mmHg from 45 to 16% in patients with severe traumatic brain injury. Here, we intended to quantify the brain tissue hypoxia burden despite implementation of a protocolized treatment approach in poor-grade SAH patients and to identify the simultaneous occurrence of pathologic values potentially amenable to treatment. METHODS: We present a bi-centric observational cohort study including 100 poor-grade SAH patients admitted to two tertiary care centers who underwent multimodal brain monitoring and were managed with a PbtO2-targeted protocolized approach. PbtO2 optimization (≥ 20 mmHg) included a stepwise neuro-intensive care approach, aiming to prevent low cerebral perfusion pressure (CPP), and blood hemoglobin, and to keep normocapnia, normoxemia, and normothermia. Based on routine blood gas analysis, hemoglobin, PaCO2, and PaO2 data were matched to 2-h averaged data of continuous CPP, PbtO2, core temperature, and to hourly cerebral microdialysis (CMD) samples over the first 11 days. RESULTS: Patients had a Glasgow Coma Scale of 3 (IQR 3-4) and were 58 years old (IQR 48-66). Overall incidence of brain tissue hypoxia was 25%, which was not different between both sites despite differences in the treatment approach. During brain tissue hypoxia, episodes of CPP < 70 mmHg (27%), PaCO2 < 35 mmHg (19%), PaO2 < 80 mmHg (14%), Hb < 9 g/dL (11%), metabolic crisis (CMD-lactate/pyruvate ratio > 40, and CMD-glucose < 0.7 mmol/L; 7%), and temperature > 38.3 °C (4%) were common. CONCLUSIONS: Our results demonstrate that brain tissue hypoxia remains common despite implementation of a PbtO2-targeted therapy in poor-grade SAH patients, suggesting room for further optimization.

Activation of Cell-Penetrating Peptides with Ionpair-π Interactions and Fluorophiles.

In this report, we elaborate on two new concepts to activate arginine-rich cell-penetrating peptides (CPPs). Early on, we have argued that repulsion-driven ion-pairing interactions with anionic lipids account for their ability to move across hydrophobic cell membranes and that hydrophobic anions such as pyrenebutyrate can accelerate this process to kinetically outcompete endosomal capture. The original explanation that the high activity of pyrenebutyrate might originate from ionpair-π interactions between CPP and activator implied that replacement of the π-basic pyrene with polarized push-pull aromatics should afford more powerful CPP activators. To elaborate on this hypothesis, we prepared a small collection of anionic amphiphiles that could recognize cations by ionpair-π interactions. Consistent with theoretical predictions, we find that parallel but not antiparallel ionpair-π interactions afford operational CPP activators in model membranes and cells. The alternative suggestion that the high activity of pyrenebutyrate might originate from self-assembly in membranes was explored with perfluorinated fatty acids. Their fluorophilicity was expected to promote self-assembly in membranes, while their high acidity should prevent charge neutralization in response to self-assembly, i.e., generate repulsion-driven ion-pairing interactions. Consistent with these expectations, we find that perfluorinated fatty acids are powerful CPP activators in HeLa cells but not in model membranes. These findings support parallel ionpair-π interactions and repulsion-driven ion pairing with self-assembled fluorophiles as innovative concepts to activate CPPs. These results also add much corroborative support for counterion-mediated uptake as the productive mode of action of arginine-rich CPPs.

Role of preoperative biliary stents, bile contamination and antibiotic prophylaxis in surgical site infections after pancreaticoduodenectomy.

BACKGROUND: The routine use of preoperative biliary drainage before pancreaticoduodenectomy (PD) remains controversial. This observational retrospective study compared stented and non-stented patients undergoing PD to assess any differences in post-operative morbidity and mortality. METHODS: A total of 180 consecutive patients who underwent PD and had intra-operative bile cultures performed between January 2010 and February 2013 were retrospectively identified. All patients received peri-operative intravenous antibiotic prophylaxis, primarily cefazolin. RESULTS: Overall incidence of post-operative surgical complications was 52.3 %, with no difference between stented and non-stented patients (53.4 % vs. 51.1 %; p = 0.875). However, stented patients had a significantly higher incidence of deep incisional surgical site infections (SSIs) (p = 0.038). In multivariate analysis, biliary stenting was confirmed as a risk factor for deep incisional SSIs (p = 0.044). Significant associations were also observed for cardiac disease (p = 0.010) and BMI ≥25 kg/m(2) (p = 0.045). Enterococcus spp. were the most frequent bacterial isolates in bile (74.5 %) and in drain fluid (69.1 %). In antimicrobial susceptibilty testing, all Enterococci isolates were cefazolin-resistant. CONCLUSION: Given the increased risk of deep incisional SSIs, preoperative biliary stenting in patients underging PD should be used only in selected patients. In stented patients, an antibiotic with anti-enterococcal activity should be chosen for PD prophylaxis.

Role of C-Reactive Protein Assessment as Early Predictor of Surgical Site Infections Development after Pancreaticoduodenectomy.

BACKGROUND: Surgical site infections (SSIs) are extremely common in pancreatic surgery and explain its considerable morbidity and mortality, even in tertiary centers. Early detection of these complications, with the help of laboratory assays, improve clinical outcome. The aim of the present study is to evaluate C-reactive protein (CRP) diagnostic accuracy as early predictor of SSIs after pancreaticoduodenectomy (PD). METHODOLOGY: We considered 251 consecutive PD. We prospectively recorded preoperative clinical and anthropometric data, intraoperative details and the postoperative outcome. In the first pool of consecutive patients (n = 150), we analyzed CRP levels from postoperative day 1 to 7 and investigated the prediction of SSIs. We then validated the diagnostic accuracy on the following 101 consecutive cases. RESULTS: At multivariate analysis, high BMI and preoperative biliary stenting appeared to be independently associated with SSIs and organ-space SSI development. The CRP cutoff of 17.27 mg/dl on postoperative day 3 (78% sensitivity, 79% specificity) and of 14.72 mg/dl on postoperative day 4 (87% sensitivity, 82% specificity) was in a position to predict the course of 78.2 and 80.2% of patients, respectively. CONCLUSIONS: CRP on postoperative days 3 and 4 seems able to predict postoperative course, selecting patients deserving intensification of diagnostic assessment; patients not satisfying these conditions could be reasonably directed toward early discharge.

The long Pentraxin PTX3 serves as an early predictive biomarker of co-infections in COVID-19.

BACKGROUND: COVID-19 clinical course is highly variable and secondary infections contribute to COVID-19 complexity. Early detection of secondary infections is clinically relevant for patient outcome. Procalcitonin (PCT) and C-reactive protein (CRP) are the most used biomarkers of infections. Pentraxin 3 (PTX3) is an acute phase protein with promising performance as early biomarker in infections. In patients with COVID-19, PTX3 plasma concentrations at hospital admission are independent predictor of poor outcome. In this study, we assessed whether PTX3 contributes to early identification of co-infections during the course of COVID-19. METHODS: We analyzed PTX3 levels in patients affected by COVID-19 with (n = 101) or without (n = 179) community or hospital-acquired fungal or bacterial secondary infections (CAIs or HAIs). FINDINGS: PTX3 plasma concentrations at diagnosis of CAI or HAI were significantly higher than those in patients without secondary infections. Compared to PCT and CRP, the increase of PTX3 plasma levels was associated with the highest hazard ratio for CAIs and HAIs (aHR 11.68 and 24.90). In multivariable Cox regression analysis, PTX3 was also the most significant predictor of 28-days mortality or intensive care unit admission of patients with potential co-infections, faring more pronounced than CRP and PCT. INTERPRETATION: PTX3 is a promising predictive biomarker for early identification and risk stratification of patients with COVID-19 and co-infections. FUNDING: Dolce & Gabbana fashion house donation; Ministero della Salute for COVID-19; EU funding within the MUR PNRR Extended Partnership initiative on Emerging Infectious Diseases (Project no. PE00000007, INF-ACT) and MUR PNRR Italian network of excellence for advanced diagnosis (Project no. PNC-E3-2022-23683266 PNC-HLS-DA); EU MSCA (project CORVOS 860044).

Quantitative Chest CT Analysis to Measure Short-Term Sequelae of COVID-19 Pneumonia: A Monocentric Prospective Study.

(1) Background: Quantitative CT analysis (QCT) has demonstrated promising results in the prognosis prediction of patients affected by COVID-19. We implemented QCT not only at diagnosis but also at short-term follow-up, pairing it with a clinical examination in search of a correlation between residual respiratory symptoms and abnormal QCT results. (2) Methods: In this prospective monocentric trial performed during the "first wave" of the Italian pandemic, i.e., from March to May 2020, we aimed to test the relationship between %deltaCL (variation of %CL-compromised lung volume) and variations of symptoms-dyspnea, cough and chest pain-at follow-up clinical assessment after hospitalization. (3) Results: 282 patients (95 females, 34%) with a median age of 60 years (IQR, 51-69) were included. We reported a correlation between changing lung abnormalities measured by QCT, and residual symptoms at short-term follow up after COVID-19 pneumonia. Independently from age, a low percentage of surviving patients (1-4%) may present residual respiratory symptoms at approximately two months after discharge. QCT was able to quantify the extent of residual lung damage underlying such symptoms, as the reduction of both %PAL (poorly aerated lung) and %CL volumes was correlated to their disappearance. (4) Conclusions QCT may be used as an objective metric for the measurement of COVID-19 sequelae.

Citrus bergamia: Kinetics of Antimicrobial Activity on Clinical Isolates.

BACKGROUND: The inappropriate use of antibiotics has increased selective pressure and the spread of multi-drug-resistant (MDR) pathogens, which reduces the possibility of effective treatment. A potential alternative therapeutic approach may be represented by essential oils, such as the distilled extract of bergamot (Citrus bergamia Risso et Poiteau). Such natural products exercise numerous biological activities, including antimicrobial effects. METHODS: This work aimed to evaluate the kinetics of the bactericidal and fungicidal activity of the distilled extract of bergamot on MDR bacteria and fungi from clinical specimens using the time-kill assay. Furthermore, the antimicrobial activity of the distilled extract of bergamot on the morphology and cellular organization of clinical pathogens was evaluated by confocal laser scanning microscopy. RESULTS: Our results demonstrated that the distilled extract of bergamot exhibited significant antimicrobial activity and a specific bactericidal effect against the bacterial and fungal strains tested. Furthermore, confocal microscope images clearly showed compromised membrane integrity, damage and cell death in bacterial samples treated with the distilled extract of bergamot. In addition, progressive alterations in cell-wall composition, cytoplasmic material and nucleus structure triggered by exposure to the distilled extract of bergamot were identified in the fungal samples considered. CONCLUSIONS: Our data suggest that the use of essential oils, such as distilled extract of bergamot (Citrus bergamia Risso et Poiteau), can represent a valid alternative therapeutic strategy to counteract antibiotic resistance of pathogens.

Compassionate use of meropenem/vaborbactam for infections caused by KPC-producing Klebsiella pneumoniae: a multicentre study.

Objectives: To explore the real-life performance of meropenem/vaborbactam for treating serious KPC-producing Klebsiella pneumoniae infections, including those resistant to ceftazidime/avibactam. Methods: A retrospective observational cohort study was conducted in 12 Italian hospitals. Enrolled patients had K. pneumoniae carbapenemase (KPC)-producing K. pneumoniae (KPC-Kp) infections (59.5% of which were ceftazidime/avibactam resistant). Patients who received ≥72 h of meropenem/vaborbactam therapy (with or without other antimicrobials) in a compassionate-use setting were included. Results: The 37 infections (all hospital-acquired) were mainly bacteraemic (BSIs, n = 23) or lower respiratory tract infections (LRTIs, n = 10). Clinical cure was achieved in 28 (75.6%) cases and microbiologically confirmed in all 25 with follow-up cultures. Three (10.7%) of the 28 clinical cures (all BSIs, 2/3 microbiologically confirmed) were followed by in-hospital recurrences after meropenem/vaborbactam was discontinued (median interval: 18 days). All three recurrences were susceptible to meropenem/vaborbactam and successfully managed with meropenem/vaborbactam combined with colistin or fosfomycin. Nine patients (24.3%) (all with BSIs or LRTIs) died in hospital with persistent signs of infection. Most were aged over 60 years, with high comorbidity burdens and INCREMENT scores ≥8. Only one had received meropenem/vaborbactam monotherapy. Six began meropenem/vaborbactam therapy >48 h after infection onset. Outcomes were unrelated to the isolate's ceftazidime/avibactam susceptibility status. The single adverse event observed consisted of severe leukopenia with thrombocytopenia. Conclusions: With the well-known limitations of real-life retrospective studies, our results support previous findings indicating that meropenem/vaborbactam therapy will be a safe, effective tool for managing serious KPC-Kp infections, including the increasing proportion displaying resistance to ceftazidime/avibactam.

What is the impact of SARS-CoV-2 pandemic on antimicrobial stewardship programs (ASPs)? The results of a survey among a regional network of infectious disease centres.

Discontinuation of antimicrobial stewardship programs (ASPs) and increased antibiotic use were described during SARS-CoV-2 pandemic. In order to measure COVID-19 impact on ASPs in a setting of high multidrug resistance organisms (MDRO) prevalence, a qualitative survey was designed. In July 2021, eighteen ID Units were asked to answer a questionnaire about their hospital characteristics, ASPs implementation status before the pandemic and impact of SARS-CoV-2 pandemic on ASPs after the 1st and 2nd pandemic waves in Italy. Nine ID centres (50%) reported a reduction of ASPs and in 7 cases (38.9%) these were suspended. After the early pandemic waves, the proportion of centres that restarted their ASPs was higher among the ID centres where antimicrobial stewardship was formally identified as a priority objective (9/11, 82%, vs 2/7, 28%). SARS-CoV-2 pandemic had a severe impact in ASPs in a region highly affected by COVID-19 and antimicrobial resistance but weaknesses related to the pre-existent ASPs might have played a role.

Role of Aryl Hydrocarbon Receptor Activation in Inflammatory Chronic Skin Diseases.

Aryl Hydrocarbon Receptor (AhR) is an evolutionary transcription factor which acts as a crucial sensor of different exogenous and endogenous molecules Recent data indicate that AhR is implicated in several physiological processes such as cell physiology, host defense, proliferation and differentiation of immune cells, and detoxification. Moreover, AhR involvement has been reported in the development and maintenance of several pathological conditions. In recent years, an increasing number of studies have accumulated highlighting the regulatory role of AhR in the physiology of the skin. However, there is evidence of both beneficial and harmful effects of AHR signaling. At present, most of the evidence concerns inflammatory skin diseases, in particular atopic dermatitis, psoriasis, acne, and hidradenitis suppurativa. This review exam-ines the role of AhR in skin homeostasis and the therapeutic implication of its pharmacological modulation in these cutaneous inflammatory diseases.

Proteomic Profile of EPS-Urine through FASP Digestion and Data-Independent Analysis.

Filter-aided sample protocol (FASP) is widely used for proteomics sample preparation because it allows to concentrate diluted samples and it is compatible with a wide variety of detergents. Bottom-up proteomics workflows like FASP increasingly rely on LC-MS/MS methods performed in data-independent analysis (DIA) mode, a scanning method that allows deep proteome coverage and low incidence of missing values. In this report, we will provide the details of a workflow that combines a FASP protocol, a double StageTip purification step and LC-MS/MS in DIA mode for urinary proteome mapping. As a model sample, we analyzed expressed prostatic secretions (EPS)-urine, a sample collected after a digital rectal exam (DRE), which is of interest in prostate cancer biomarker discovery studies.

Hospital-Acquired Infections in Critically Ill Patients With COVID-19.

BACKGROUND: Few small studies have described hospital-acquired infections (HAIs) occurring in patients with COVID-19. RESEARCH QUESTION: What characteristics in critically ill patients with COVID-19 are associated with HAIs and how are HAIs associated with outcomes in these patients? STUDY DESIGN AND METHODS: Multicenter retrospective analysis of prospectively collected data including adult patients with severe COVID-19 admitted to eight Italian hub hospitals from February 20, 2020, through May 20, 2020. Descriptive statistics and univariate and multivariate Weibull regression models were used to assess incidence, microbial cause, resistance patterns, risk factors (ie, demographics, comorbidities, exposure to medication), and impact on outcomes (ie, ICU discharge, length of ICU and hospital stays, and duration of mechanical ventilation) of microbiologically confirmed HAIs. RESULTS: Of the 774 included patients, 359 patients (46%) demonstrated 759 HAIs (44.7 infections/1,000 ICU patient-days; 35% multidrug-resistant [MDR] bacteria). Ventilator-associated pneumonia (VAP; n = 389 [50%]), bloodstream infections (BSIs; n = 183 [34%]), and catheter-related BSIs (n = 74 [10%]) were the most frequent HAIs, with 26.0 (95% CI, 23.6-28.8) VAPs per 1,000 intubation-days, 11.7 (95% CI, 10.1-13.5) BSIs per 1,000 ICU patient-days, and 4.7 (95% CI, 3.8-5.9) catheter-related BSIs per 1,000 ICU patient-days. Gram-negative bacteria (especially Enterobacterales) and Staphylococcus aureus caused 64% and 28% of cases of VAP, respectively. Variables independently associated with infection were age, positive end expiratory pressure, and treatment with broad-spectrum antibiotics at admission. Two hundred thirty-four patients (30%) died in the ICU (15.3 deaths/1,000 ICU patient-days). Patients with HAIs complicated by septic shock showed an almost doubled mortality rate (52% vs 29%), whereas noncomplicated infections did not affect mortality. HAIs prolonged mechanical ventilation (median, 24 days [interquartile range (IQR), 14-39 days] vs 9 days [IQR, 5-13 days]; P < .001), ICU stay (24 days [IQR, 16-41 days] vs 9 days [IQR, 6-14 days]; P = .003), and hospital stay (42 days [IQR, 25-59 days] vs 23 days [IQR, 13-34 days]; P < .001). INTERPRETATION: Critically ill patients with COVID-19 are at high risk for HAIs, especially VAPs and BSIs resulting from MDR organisms. HAIs prolong mechanical ventilation and hospitalization, and HAIs complicated by septic shock almost double mortality. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT04388670; URL: www.clinicaltrials.gov.