Clinical and bacterial characteristics of Pseudomonas aeruginosa affecting the outcome of patients with bacteraemic pneumonia.

Few studies have assessed the clinical and bacterial characteristics of Pseudomonas aeruginosa (PA) bacteraemic pneumonia (BP) episodes. This study analysed all non-duplicate PA-BP episodes from a tertiary hospital in 2013-2017. Epidemiology, clinical data, antimicrobial therapy and outcomes were recorded. Whole-genome sequencing was performed on PA blood isolates. The impact on early and late overall mortality of host, antimicrobial treatment and pathogen factors was assessed by multivariate logistic regression analysis. Of 55 PA-BP episodes, 32 (58.2%) were caused by extensively drug-resistant (XDR) PA. ST175 (32.7%) and ST235 (25.5%) were the most frequent high-risk clones. ß-Lactamases/carbapenemases were detected in 29 isolates, including blaVIM-2 (27.2%) and blaGES type (25.5%) [blaGES-5 (20.0%), blaGES-1 (3.6%) and blaGES-20 (1.8%)]. The most prevalent O-antigen serotypes were O4 (34.5%) and O11 (30.9%). Overall, an extensive virulome was identified in all isolates. Early mortality (56.4%) was independently associated with severe neutropenia (aOR = 4.64, 95% CI 1.11-19.33; P = 0.035) and inappropriate empirical antimicrobial therapy (aOR = 5.71, 95% CI 1.41-22.98; P = 0.014). Additionally, late mortality (67.3%) was influenced by septic shock (aOR = 8.85, 95% CI 2.00-39.16; P = 0.004) and XDR phenotype (aOR = 5.46, 95% CI 1.25-23.85; P = 0.024). Moreover, specific genetic backgrounds [ST235, blaGES, gyrA (T83I), parC (S87L), exoU and O11 serotype] showed significant differences in patient outcomes. Our results confirm the high mortality associated with PA-BP. Besides relevant clinical characteristics and inappropriate empirical therapy, bacteria-specific genetics factors, such as XDR phenotype, adversely affect the outcome of PA-BP.

Evaluationof the New Outer Membrane Protein A Epitope-based Vaccines for Mice Model of Acinetobacter baumannii Associated Pneumonia and Sepsis Infection.

Nosocomial infections caused by Acinetobacter baumannii (A. baumannii) nosocomial infections caused by Acinetobacter baumannii (A. baumannii) are considered as a global serious problem in hospitalized patients because of emerging antibiotic resistance. Immunotherapy approaches are promising to prevent such infections. In our previous study, five antigenic epitopes of outer membrane protein A (OmpA), as the most dangerous virulence molecule in A. baumanii, were predicted in silico. In this study, the investigators evaluated some immunological aspects of the peptides. Five peptides were separately injected into C5BL/6 mice; then the cytokine production (interleukin-4 and interferon-gamma) of splenocytes and opsonophagocytic activity of immunized serum were assessed. To identify the protective function of the peptides, animal models of sepsis and pneumonia infections were actively and passively immunized with selected peptides and pooled sera of immunized mice, respectively. Then, survival rates of them were compared with the non-infected controls. Based on the results, activated spleen cells in P127 peptide-immunized mice exhibited an increase level of IFN-γ compared with the other experimental groups, but not about the IL-4 concentration. The results of opsonophagocytic assay revealed an appropriate killing activity of produced antibodies against A. baumannii in a dose-dependent manner. Further, the survival rates of the mice under passive immunization with the immunized sera or active immunization with P127 peptide were significantly more than those in the control group. Moreover, the survival rate of the P127 peptide immunized group was considerably higher than that among the other peptide-immunized group. In conclusion, findings indicated that peptides derived from outer membrane protein-A can be used as a promising tool for designing the epitope-based vaccines against infections caused by A. baumannii.

Pulmonary mycobacterial infection is associated with increased mortality in patients with acute respiratory distress syndrome.

ABSTRACT: Although pulmonary mycobacterial infection is associated with acute respiratory distress syndrome (ARDS) in critically ill patients, its clinical implication on patients with ARDS has not been clearly elucidated. The aim of study was to investigate the clinical significance of pulmonary mycobacterial infection in patients with ARDS.Between January 2014 and April 2019, medical records of 229 patients with ARDS who met the Berlin criteria and received invasive mechanical ventilation in medical intensive care unit were reviewed. Clinical characteristics and the rate of mortality between patients with and without pulmonary mycobacterial infection were compared. Factors associated with a 28-day mortality were analyzed statistically.Twenty two (9.6%) patients were infected with pulmonary mycobacteria (18 with tuberculosis and 4 with non-tuberculous mycobacteria). There were no differences in baseline characteristics, the severity of illness scores. Other than a higher rate of renal replacement therapy required in those without pulmonary mycobacterial infection, the use of adjunctive therapy did not differ between the groups. The 28- day mortality rate was significantly higher in patients with pulmonary mycobacterial infection (81.8% vs 58%, P = .019). Pulmonary mycobacterial infection was significantly associated with 28-day mortality (hazard ratio 1.852, 95% confidence interval 1.108-3.095, P = .019).Pulmonary mycobacterial infection was associated with increased 28-day mortality in patients with ARDS.

Association between mortality and highly antimicrobial-resistant bacteria in intensive care unit-acquired pneumonia.

Data on the relationship between antimicrobial resistance and mortality remain scarce, and this relationship needs to be investigated in intensive care units (ICUs). The aim of this study was to compare the ICU mortality rates between patients with ICU-acquired pneumonia due to highly antimicrobial-resistant (HAMR) bacteria and those with ICU-acquired pneumonia due to non-HAMR bacteria. We conducted a multicenter, retrospective cohort study using the French National Surveillance Network for Healthcare Associated Infection in ICUs ("REA-Raisin") database, gathering data from 200 ICUs from January 2007 to December 2016. We assessed all adult patients who were hospitalized for at least 48 h and presented with ICU-acquired pneumonia caused by S. aureus, Enterobacteriaceae, P. aeruginosa, or A. baumannii. The association between pneumonia caused by HAMR bacteria and ICU mortality was analyzed using the whole sample and using a 1:2 matched sample. Among the 18,497 patients with at least one documented case of ICU-acquired pneumonia caused by S. aureus, Enterobacteriaceae, P. aeruginosa, or A. baumannii, 3081 (16.4%) had HAMR bacteria. The HAMR group was associated with increased ICU mortality (40.3% vs. 30%, odds ratio (OR) 95%, CI 1.57 [1.45-1.70], P < 0.001). This association was confirmed in the matched sample (3006 HAMR and 5640 non-HAMR, OR 95%, CI 1.39 [1.27-1.52], P < 0.001) and after adjusting for confounding factors (OR ranged from 1.34 to 1.39, all P < 0.001). Our findings suggest that ICU-acquired pneumonia due to HAMR bacteria is associated with an increased ICU mortality rate, ICU length of stay, and mechanical ventilation duration.

Etiology, Clinical Course, and Outcomes of Pneumonia in the Elderly: A Retrospective and Prospective Cohort Study in Thailand.

Pneumonia is a leading cause of hospitalization and death among elderly adults. We performed a retrospective and prospective observational study to describe the etiology, clinical course, and outcomes of pneumonia for patients 60 years and older in Thailand. We enrolled 490 patients; 440 patients were included in the retrospective study and 50 patients were included in the prospective study. The CURB-65 score and a modified SMART-COP score (SMART-CO score) were used to assess disease severity. The median patient age was 80 years (interquartile range, 70-87 years); 51.2% were men. Klebsiella pneumoniae (20.4%) and Pseudomonas aeruginosa (15.5%) were the most common causative agents of pneumonia. A significant minority (23%) of patients were admitted to the intensive care unit (ICU), and mortality among this subset of patients was 45%. Most patients (80.8%) survived and were discharged from the hospital. The median duration of hospitalization was 8 days (interquartile range, 4-16 days). In contrast, 17.6% of patients died while undergoing care and 30-day mortality was 14%. Factors significantly associated with mortality were advanced age (P = 0.004), male sex (P = 0.005), multiple bacterial infections (P = 0.007; relative risk [RR], 1.88; 95% confidence interval [CI], 1.19-2.79), infection with multi-drug-resistant/extended-spectrum B-lactamase-producing organisms (P < 0.001; RR, 2.82; 95% CI, 1.83-4.85), ICU admission (P < 0.001; RR, 1.8; 95% CI, 1.4-2.3), and complications of pneumonia (P < 0.001; RR, 2.5; 95% CI, 1.8-3.4). Patients with higher SMART-CO and CURB-65 scores had higher rates of ICU admission and higher 30-day mortality rates (P < 0.001). These results emphasize the importance of Gram-negative bacteria, particularly K. pneumoniae and P. aeruginosa, as major causes of pneumonia among the elderly in contrast to other reports, Streptococcus pneumoniae is a common cause of pneumonia among elderly individuals worldwide. The SMART-COP and CURB-65 scores were developed to assess pneumonia severity and predict mortality of young adults with pneumonia. Few studies have examined the appropriateness of these scores for elderly patients with multiple comorbidities. A limited number of studies have used modified versions of these scores among elderly individuals. We found that Gram-negative bacteria has a major role in the etiology of pneumonia among elderly individuals in Southeast Asia. A significant proportion of elderly individuals with low CURB-65 scores were admitted to the hospital, indicating that hospital admission may reflect fragility among elderly individuals with low CURB-65 scores. The modified SMART-COP score (SMART-CO score) sufficiently predicted intensive care unit admission and the need for intensive vasopressor or respiratory support. A SMART-CO score ≥ 7 accurately predicted 30-day mortality.

Elastase Activity From Pseudomonas aeruginosa Respiratory Isolates and ICU Mortality.

BACKGROUND: Pseudomonas aeruginosa (PA) is a common cause of respiratory infection and morbidity. Pseudomonas elastase is an important virulence factor regulated by the lasR gene. Whether PA elastase activity is associated with worse clinical outcomes in ICU patients is unknown. RESEARCH QUESTION: Is there an association between PA elastase activity and worse host outcomes in a cohort of ICU patients? METHODS: PA respiratory isolates from 238 unique ICU patients from two tertiary-care centers within the University of Pittsburgh Medical Center health system were prospectively collected and screened for total protease and elastase activity, biofilm production, antimicrobial resistance, and polymicrobial status. The association between pathogen characteristics and 30-day and 90-day mortality was calculated using logistic regression. For subgroup analysis, two patterns of early (≤72 h) and late sample (>72 h) collection from the index ICU admission were distinguished using a finite mixture model. Lung inflammation and injury was evaluated in a mouse model using a PA high elastase vs low elastase producer. RESULTS: PA elastase activity was common in ICU respiratory isolates representing 75% of samples and was associated with increased 30-day mortality (adjusted OR [95% CI]: 1.39 [1.05-1.83]). Subgroup analysis demonstrated that elastase activity was a risk factor for 30- and 90-day mortality in the early sample group, whereas antimicrobial resistance was a risk factor for 90-day mortality in the late sample group. Whole genome sequencing of high and low elastase producers showed that predicted loss-of-function lasR genotypes were less common among high elastase producers. Mice infected with a high elastase producer showed increased lung bacterial burden and inflammatory profile compared with mice infected with a low elastase producer. INTERPRETATION: Elastase activity is associated with 30-day ICU mortality. A high elastase producing clinical isolate confers increased lung tissue inflammation compared with a low elastase producer in vivo.

Management of possible serious bacterial infection in young infants where referral is not possible in the context of existing health system structure in Ibadan, South-west Nigeria.

INTRODUCTION: Neonatal infections contribute substantially to infant mortality in Nigeria and globally. Management requires hospitalization, which is not accessible to many in low resource settings. World Health Organization developed a guideline to manage possible serious bacterial infection (PSBI) in young infants up to two months of age when a referral is not feasible. We evaluated the feasibility of implementing this guideline to achieve high coverage of treatment. METHODS: This implementation research was conducted in out-patient settings of eight primary health care centres (PHC) in Lagelu Local Government Area (LGA) of Ibadan, Oyo State, Nigeria. We conducted policy dialogue with the Federal and State officials to adopt the WHO guideline within the existing programme setting and held orientation and sensitization meetings with communities. We established a Technical Support Unit (TSU), built the capacity of health care providers, supervised and mentored them, monitored the quality of services and collected data for management and outcomes of sick young infants with PSBI signs. The Primary Health Care Directorate of the state ministry and the local government led the implementation and provided technical support. The enablers and barriers to implementation were documented. RESULTS: From 1 April 2016 to 31 July 2017 we identified 5278 live births and of these, 1214 had a sign of PSBI. Assuming 30% of births were missed due to temporary migration to maternal homes for delivery care and approximately 45% cases came from outside the catchment area due to free availability of medicines, the treatment coverage was 97.3% (668 cases/6861 expected births) with an expected 10% PSBI prevalence within the first 2 months of life. Of 1214 infants with PSBI, 392 (32%) infants 7-59 days had only fast breathing (pneumonia), 338 (27.8%) infants 0-6 days had only fast breathing (severe pneumonia), 462 (38%) presented with signs of clinical severe infection (CSI) and 22 (1.8%) with signs of critical illness. All but two, 7-59 days old infants with pneumonia were treated with oral amoxicillin without a referral; 80% (312/390) adhered to full treatment; 97.7% (381/390) were cured, and no deaths were reported. Referral to the hospital was not accepted by 87.7% (721/822) families of infants presenting with signs of PSBI needing hospitalization (critical illness 5/22; clinical severe infection; 399/462 and severe pneumonia 317/338). They were treated on an outpatient basis with two days of injectable gentamicin and seven days of oral amoxicillin. Among these 81% (584/721) completed treatment; 97% (700/721) were cured, and three deaths were reported (two with critical illness and one with clinical severe infection). We identified health system gaps including lack of staff motivation and work strikes, medicines stockouts, sub-optimal home visits that affected implementation. CONCLUSIONS: When a referral is not feasible, outpatient treatment for young infants with signs of PSBI is possible within existing programme structures in Nigeria with high coverage and low case fatality. To scale up this intervention successfully, government commitment is needed to strengthen the health system, motivate and train health workers, provide necessary commodities, establish technical support for implementation and strengthen linkages with communities. REGISTRATION: Trial is registered on Australian New Zealand Clinical Trials Registry (ANZCTR) ACTRN12617001373369.

Amikacin nebulization for the adjunctive therapy of gram-negative pneumonia in mechanically ventilated patients: a systematic review and meta-analysis of randomized controlled trials.

Treatment of ventilated patients with gram-negative pneumonia (GNP) is often unsuccessful. We aimed to assess the efficacy and safety of nebulized amikacin (NA) as adjunctive therapy to systemic antibiotics in this patient population. PubMed, Embase, China national knowledge infrastructure, Wanfang, and the Cochrane database were searched for randomized controlled trials (RCTs) investigating the effect of NA as adjunctive therapy in ventilated adult patients with GNP. Heterogeneity was explored using subgroup analysis and sensitivity analysis. The Grading of recommendations assessment, development, and evaluation approach was used to assess the certainty of the evidence. Thirteen RCTs with 1733 adults were included. The pooled results showed NA had better microbiologic eradication (RR = 1.51, 95% CI 1.35 to 1.69, P < 0.0001) and improved clinical response (RR = 1.23; 95% CI 1.13 to 1.34; P < 0.0001) when compared with control. Meanwhile, overall mortality, pneumonia associated mortality, duration of mechanical ventilation, length of stay in ICU and change of clinical pneumonia infection scores were similar between NA and control groups. Additionally, NA did not add significant nephrotoxicity while could cause more bronchospasm. The use of NA adjunctive to systemic antibiotics therapy showed better benefits in ventilated patients with GNP. More well-designed RCTs are still needed to confirm our results.

Ventilator-associated bacterial pneumonia in coronavirus 2019 disease, a retrospective monocentric cohort study.

INTRODUCTION: Severe coronavirus 2019 disease (CoViD-19) may lead to respiratory failure and mechanical ventilation. Therefore, ventilator associated pneumonia (VAP) may complicate the course of the disease. The aim of the current article was to investigate possible predictive factors for bacterial VAP on a retrospective manner, in a cohort of mechanically ventilated CoViD-19 patients. Additionally, determinant factors of lethality were analyzed. METHODS: Medical records of patients hospitalized in the intensive care units (ICU) at the university hospital UZ Brussel during the epidemic were reviewed. VAP was defined following the National Healthcare Safety Network 2017 criteria. Univariate and multivariate logistic regressions analyses were performed. RESULTS: Among the 39 patients included in the study, 54% were diagnosed with bacterial VAP. Case fatality rate was 44%, but 59% of the deceased patients had a do-not-resuscitate status. Multivariate logistic regression for prediction of VAP showed significant differences in duration of ICU hospitalization and in minimal lung compliance. Additional analyses were performed on CoViD-19 patients who were affected by bacterial respiratory superinfection. The responsible pathogens correspond to the commonly found bacteria in VAP. However, 71% of the isolated germs were multi-drug resistant and bacteraemia was reported in 38%. Multivariate analyses for prediction of lethality found significant difference in SOFA score. CONCLUSIONS: Mechanically ventilated CoViD-19 patients might frequently develop VAP. Longer ICU hospitalization was associated with pulmonary superinfection in the current cohort. Moreover, decreased minimal lung compliance was correlated to VAP and higher SOFA score at VAP diagnosis was associated with lethality.

Efficacy of adjunctive nebulized colistin in critically ill patients with nosocomial carbapenem-resistant Gram-negative bacterial pneumonia: a multi-centre observational study.

OBJECTIVES: To investigate the association between adjunctive nebulized colistin and treatment outcomes in critically ill patients with nosocomial carbapenem-resistant Gram-negative bacterial (CR-GNB) pneumonia. METHODS: This retrospective, multi-centre, cohort study included individuals admitted to the intensive care unit with nosocomial pneumonia caused by colistin-susceptible CR-GNB. Enrolled patients were divided into groups with/without nebulized colistin as adjunct to at least one effective intravenous antibiotic. Propensity score matching was performed in the original cohort (model 1) and a time-window bias-adjusted cohort (model 2). The association between adjunctive nebulized colistin and treatment outcomes was analysed. RESULTS: In total, 181 and 326 patients treated with and without nebulized colistin, respectively, were enrolled for analysis. The day 14 clinical failure rate and mortality rate were 41.4% (75/181) versus 46% (150/326), and 14.9% (27/181) versus 21.8% (71/326), respectively. In the propensity score-matching analysis, patients with nebulized colistin had lower day 14 clinical failure rates (model 1: 41% (68/166) versus 54.2% (90/166), p 0.016; model 2: 35.3% (41/116) versus 56.9% (66/116), p 0.001). On multivariate analysis, nebulized colistin was an independent factor associated with fewer day 14 clinical failures (model 1: adjusted odds ratio (aOR) 0.59, 95% CI 0.37-0.92; model 2: aOR 0.37, 95% CI 0.21-0.65). Nebulized colistin was not associated independently with a lower 14-day mortality rate in the time-dependent analysis in both models 1 and 2. CONCLUSIONS: Adjunctive nebulized colistin was associated with lower day 14 clinical failure rate, but not lower 14-day mortality rate, in critically ill patients with nosocomial pneumonia caused by colistin-susceptible CR-GNB.

Estrogen Alleviates Sex-Dependent Differences in Lung Bacterial Clearance and Mortality Secondary to Bacterial Pneumonia after Traumatic Brain Injury.

Traumatic brain injury (TBI) is the leading cause of injury-related death and disability in patients under the age of 46 years. Survivors of the initial injury often endure systemic complications such as pulmonary infection, and Pseudomonas aeruginosa is one of the most common causes of nosocomial pneumonia in intensive care units. Female patients are less likely to develop secondary pneumonia after TBI, and pre-clinical studies have revealed a salutary role for estrogen after trauma. Therefore, we hypothesized that female mice would experience less mortality after post-TBI pneumonia with P. aeruginosa. We employed a mouse model of TBI followed by P. aeruginosa pneumonia. Male mice had greater mortality and impaired lung bacterial clearance after post-TBI pneumonia compared with female mice. This was confirmed as a difference in sex hormones, as oophorectomized wild-type mice had mortality and lung bacterial clearance similar to male mice. There were differences in tumor necrosis factor-α secretion in male and female alveolar macrophages after P. aeruginosa infection. Finally, injection of male or oophorectomized wild-type female mice with estrogen restored lung bacterial clearance and prevented mortality. Our model of TBI followed by P. aeruginosa pneumonia is among the first to reveal sex dimorphism in secondary, long-term TBI complications.

Clinical Policy: Critical Issues in the Management of Adult Patients Presenting to the Emergency Department With Community-Acquired Pneumonia.

This clinical policy from the American College of Emergency Physicians is a revision of the 2009 "Clinical Policy: Critical Issues in the Management of Adult Patients Presenting to the Emergency Department With Community-Acquired Pneumonia." A writing subcommittee conducted a systematic review of the literature to derive evidence-based recommendations to answer the following clinical questions: (1) In the adult emergency department patient diagnosed with community-acquired pneumonia, what clinical decision aids can inform the determination of patient disposition? (2) In the adult emergency department patient with community-acquired pneumonia, what biomarkers can be used to direct initial antimicrobial therapy? (3) In the adult emergency department patient diagnosed with community-acquired pneumonia, does a single dose of parenteral antibiotics in the emergency department followed by oral treatment versus oral treatment alone improve outcomes? Evidence was graded and recommendations were made based on the strength of the available data.

One year after ICU admission for severe community-acquired pneumonia of bacterial, viral or unidentified etiology. What are the outcomes?

INTRODUCTION: Multiplex polymerase chain reaction (mPCR) for respiratory virus testing is increasingly used in community-acquired pneumonia (CAP), however data on one-year outcome in intensive care unit (ICU) patients with reference to the causative pathogen are scarce. MATERIALS AND METHODS: We performed a single-center retrospective study in 123 ICU patients who had undergone respiratory virus testing for CAP by mPCR and with known one-year survival status. Functional status including dyspnea (mMRC score), autonomy (ADL Katz score) and need for new home-care ventilatory support was assessed at a one-year post-ICU follow-up. Mortality rates and functional status were compared in patients with CAP of a bacterial, viral or unidentified etiology one year after ICU admission. RESULTS: The bacterial, viral and unidentified groups included 19 (15.4%), 37 (30.1%), and 67 (54.5%) patients, respectively. In multivariate analysis, one-year mortality in the bacterial group was higher compared to the viral group (HR 2.92, 95% CI 1.71-7.28, p = 0.02) and tended to be higher compared to the unidentified etiology group (p = 0.06); but no difference was found between the viral and the unidentified etiology group (p = 0.43). In 64/83 one-year survivors with a post-ICU follow-up consultation, there were no differences in mMRC score, ADL Katz score and new home-care ventilatory support between the groups (p = 0.52, p = 0.37, p = 0.24, respectively). Severe dyspnea (mMRC score = 4 or death), severe autonomy deficiencies (ADL Katz score ≤ 2 or death), and major adverse respiratory events (new home-care ventilatory support or death) were observed in 52/104 (50.0%), 47/104 (45.2%), and 65/104 (62.5%) patients, respectively; with no difference between the bacterial, viral and unidentified group: p = 0.58, p = 0.06, p = 0.61, respectively. CONCLUSIONS: CAP of bacterial origin had a poorer outcome than CAP of viral or unidentified origin. At one-year, impairment of functional status was frequently observed, with no difference according to the etiology.

SARS-CoV-2-related pneumonia cases in pneumonia picture in Russia in March-May 2020: Secondary bacterial pneumonia and viral co-infections.

BACKGROUND: We are communicating the results of investigating statistics on SARS-CoV-2-related pneumonias in Russia: percentage, mortality, cases with other viral agents, cases accompanied by secondary bacterial pneumonias, age breakdown, clinical course and outcome. METHODS: We studied two sampling sets (Set 1 and Set 2). Set 1 consisted of results of testing 3382 assays of out-patients and hospital patients (5-88 years old) with community-acquired and hospital-acquired pneumonia of yet undetermined aetiology. Set 2 contained results of 1204 assays of hospital patients (12-94 years old) with pneumonia and COVID-19 already diagnosed by molecular biological techniques in test laboratories. The results were collected in twelve Russian cities/provinces in time range 2 March - 5 May 2020. Assays were analysed for 10 bacterial, 15 viral, 2 fungal and 2 parasitic aetiological agents. RESULTS: In Set 1, 4.35% of total pneumonia cases were related to SARS-CoV-2, with substantially larger proportion (18.75%) of deaths of pneumonia with COVID-19 diagnosed. However, studying Set 2, we revealed that 52.82% patients in it were also positive for different typical and atypical aetiological agents usually causing pneumonia. 433 COVID-19 patients (35.96%) were tested positive for various bacterial aetiological agents, with Streptococcus pneumoniae, Staphylococcus aureus and Haemophilus influenzae infections accounting for the majority of secondary pneumonia cases. CONCLUSIONS: SARS-CoV-2, a low-pathogenic virus itself, becomes exceptionally dangerous if secondary bacterial pneumonia attacks a COVID-19 patient as a complication. An essential part of the severest complications and mortality associated with COVID-19 in Russia in March-May 2020, may be attributed to secondary bacterial pneumonia and to a much less extent viral co-infections. The problem of hospital-acquired bacterial infection is exceptionally urgent in treating SARS-CoV-2 patients. The risk of secondary bacterial pneumonia and its further complications, should be given very serious attention in combating SARS-CoV-2.

Impact of reducing the duration of antibiotic treatment on the long-term prognosis of community acquired pneumonia.

BACKGROUND: The optimal duration of antibiotic treatment for community-acquired pneumonia (CAP) is not well established. The aim of this study was to assess the impact of reducing the duration of antibiotic treatment on long-term prognosis in patients hospitalized with CAP. METHODS: This was a multicenter study assessing complications developed during 1 year of patients previously hospitalized with CAP who had been included in a randomized clinical trial concerning the duration of antibiotic treatment. Mortality at 90 days, at 180 days and at 1 year was analyzed, as well as new admissions and cardiovascular complications. A subanalysis was carried out in one of the hospitals by measuring C-reactive protein (CRP), procalcitonin (PCT) and proadrenomedullin (proADM) at admission, at day 5 and at day 30. RESULTS: A total of 312 patients were included, 150 in the control group and 162 in the intervention group. Ninety day, 180 day and 1-year mortality in the per-protocol analysis were 8 (2.57%), 10 (3.22%) and 14 (4.50%), respectively. There were no significant differences between both groups in terms of 1-year mortality (p = 0.94), new admissions (p = 0.84) or cardiovascular events (p = 0.33). No differences were observed between biomarker level differences from day 5 to day 30 (CRP p = 0.29; PCT p = 0.44; proADM p = 0.52). CONCLUSIONS: Reducing antibiotic treatment in hospitalized patients with CAP based on clinical stability criteria is safe, without leading to a greater number of long-term complications.

Lipoprotein concentrations over time in the intensive care unit COVID-19 patients: Results from the ApoCOVID study.

INTRODUCTION: Severe acute respiratory syndrome coronavirus2 has caused a global pandemic of coronavirus disease 2019 (COVID-19). High-density lipoproteins (HDLs), particles chiefly known for their reverse cholesterol transport function, also display pleiotropic properties, including anti-inflammatory or antioxidant functions. HDLs and low-density lipoproteins (LDLs) can neutralize lipopolysaccharides and increase bacterial clearance. HDL cholesterol (HDL-C) and LDL cholesterol (LDL-C) decrease during bacterial sepsis, and an association has been reported between low lipoprotein levels and poor patient outcomes. The goal of this study was to characterize the lipoprotein profiles of severe ICU patients hospitalized for COVID-19 pneumonia and to assess their changes during bacterial ventilator-associated pneumonia (VAP) superinfection. METHODS: A prospective study was conducted in a university hospital ICU. All consecutive patients admitted for COVID-19 pneumonia were included. Lipoprotein levels were assessed at admission and daily thereafter. The assessed outcomes were survival at 28 days and the incidence of VAP. RESULTS: A total of 48 patients were included. Upon admission, lipoprotein concentrations were low, typically under the reference values ([HDL-C] = 0.7[0.5-0.9] mmol/L; [LDL-C] = 1.8[1.3-2.3] mmol/L). A statistically significant increase in HDL-C and LDL-C over time during the ICU stay was found. There was no relationship between HDL-C and LDL-C concentrations and mortality on day 28 (log-rank p = 0.554 and p = 0.083, respectively). A comparison of alive and dead patients on day 28 did not reveal any differences in HDL-C and LDL-C concentrations over time. Bacterial VAP was frequent (64%). An association was observed between HDL-C and LDL-C concentrations on the day of the first VAP diagnosis and mortality ([HDL-C] = 0.6[0.5-0.9] mmol/L in survivors vs. [HDL-C] = 0.5[0.3-0.6] mmol/L in nonsurvivors, p = 0.036; [LDL-C] = 2.2[1.9-3.0] mmol/L in survivors vs. [LDL-C] = 1.3[0.9-2.0] mmol/L in nonsurvivors, p = 0.006). CONCLUSION: HDL-C and LDL-C concentrations upon ICU admission are low in severe COVID-19 pneumonia patients but are not associated with poor outcomes. However, low lipoprotein concentrations in the case of bacterial superinfection during ICU hospitalization are associated with mortality, which reinforces the potential role of these particles during bacterial sepsis.

Severe respiratory viral infection induces procalcitonin in the absence of bacterial pneumonia.

INTRODUCTION: Procalcitonin expression is thought to be stimulated by bacteria and suppressed by viruses via interferon signalling. Consequently, during respiratory viral illness, clinicians often interpret elevated procalcitonin as evidence of bacterial coinfection, prompting antibiotic administration. We sought to evaluate the validity of this practice and the underlying assumption that viral infection inhibits procalcitonin synthesis. METHODS: We conducted a retrospective cohort study of patients hospitalised with pure viral infection (n=2075) versus bacterial coinfection (n=179). The ability of procalcitonin to distinguish these groups was assessed. In addition, procalcitonin and interferon gene expression were evaluated in murine and cellular models of influenza infection. RESULTS: Patients with bacterial coinfection had higher procalcitonin than those with pure viral infection, but also more severe disease and higher mortality (p<0.001). After matching for severity, the specificity of procalcitonin for bacterial coinfection dropped substantially, from 72% to 61%. In fact, receiver operating characteristic curve analysis showed that procalcitonin was a better indicator of multiple indices of severity (eg, organ failures and mortality) than of coinfection. Accordingly, patients with severe viral infection had elevated procalcitonin. In murine and cellular models of influenza infection, procalcitonin was also elevated despite bacteriologic sterility and correlated with markers of severity. Interferon signalling did not abrogate procalcitonin synthesis. DISCUSSION: These studies reveal that procalcitonin rises during pure viral infection in proportion to disease severity and is not suppressed by interferon signalling, in contrast to prior models of procalcitonin regulation. Applied clinically, our data suggest that procalcitonin represents a better indicator of disease severity than bacterial coinfection during viral respiratory infection.