Clinical practice. Community-acquired pneumonia

Bacterial infection adversely increases the risk of decompensation in patients with hepatitis B virus-related compensated cirrhosis: a retrospective study

BACKGROUND

Hepatitis B virus related compensated cirrhosis generally has a favorable prognosis until decompensation occurs. Bacterial infections are prevalent in Hepatitis B virus related decompensated cirrhosis.Bacterial infection and decompensated hepatitis B cirrhosis are mutually reinforcing. And it also interacts with and promotes certain decompensation-related events. However, the impact of bacterial infections on the progression from compensated to decompensated cirrhosis in Hepatitis B patients remains unclear.

METHODS

We retrospectively analyzed the baseline characteristics of 1,011 patients with Hepatitis B virus related compensated cirrhosis. Using time-dependent regression analysis, we evaluated whether bacterial infections increase the risk of decompensation, defined as the occurrence of ascites, hepatic encephalopathy, or variceal bleeding.

RESULTS

A total of 1,011 patients were retrospectively analyzed over a median follow-up period of 79 months. Bacterial infections were observed in 89 patients (8.8%). Respiratory and urinary tract infections were the most common bacterial infections.Decompensation occurred in 44.9% of patients with bacterial infections, compared to 9% of those without BIs. Patients with bacterial infections had a higher risk of decompensation ([OR] 1.024; 95% CI 1.016-1.032; p < 0.001) than those without bacterial infections.

CONCLUSION

Our findings suggest that bacterial infections have a significant impact on the progression of hepatitis B virus related compensated cirrhosis, notably increasing the risk of decompensation.

Diagnostic test accuracy of cellular analysis of bronchoalveolar lavage fluid in distinguishing pulmonary infectious and non-infectious diseases in patients with pulmonary shadow

Purpose

This study aims to assess the diagnostic accuracy of cellular analysis of bronchoalveolar lavage fluid (BALF) in distinguishing between pulmonary infectious and non-infectious diseases in patients with pulmonary shadows. Additionally, it will develop and validate a novel scoring system based on a nomogram for the purpose of differential diagnosis.

Methods

A retrospective analysis was conducted involving data from 222 patients with pulmonary shadows, whose etiological factors were determined at our institution. The cohort was randomly allocated into a training set comprising 155 patients and a validation set of 67 patients, (ratio of 7:3), the least absolute shrinkage and selection operator (LASSO) regression model was applied to optimize feature selection for the model. Multivariable logistic regression analysis was applied to construct a predictive model. The receiver operating characteristic curve (ROC) and calibration curve were utilized to assess the prediction accuracy of the model. Decision curve analysis (DCA) and clinical impact curve (CIC) were employed to evaluate the clinical applicability of the model. Moreover, model comparison was set to evaluate the discrimination and clinical usefulness between the nomogram and the risk factors.

Results

Among the relevant predictors, the percentage of neutrophils in BALF (BALF NP) exhibited the most substantial differentiation, as evidenced by the largest area under the ROC curve (AUC = 0.783, 95% CI: 0.713-0.854). A BALF NP threshold of ≥16% yielded a sensitivity of 72%, specificity of 70%, a positive likelihood ratio of 2.07, and a negative likelihood ratio of 0.38. LASSO and multivariate regression analyses indicated that BALF NP (p < 0.001, OR = 1.04, 95% CI: 1.02-1.06) and procalcitonin (p < 0.021, OR = 52.60, 95% CI: 1.83-1510.06) serve as independent predictors of pulmonary infection. The AUCs for the training and validation sets were determined to be 0.853 (95% CI: 0.806-0.918) and 0.801 (95% CI: 0.697-0.904), respectively, with calibration curves demonstrating strong concordance. The DCA and CIC analyses indicated that the nomogram model possesses commendable clinical applicability. In models comparison, ROC analyses revealed that the nomogram exhibited superior discriminatory accuracy compared to alternative models, with DCA further identifying the nomogram as offering the highest net benefits across a broad spectrum of threshold probabilities.

Conclusion

BALF NP ≥16% serves as an effective discriminator between pulmonary infectious and non-infectious diseases in patients with pulmonary shadows. We have developed a nomogram model incorporating BALF NP and procalcitonin (PCT), which has proven to be a valuable tool for predicting the risk of pulmonary infections. This model holds significant potential to assist clinicians in making informed treatment decisions.

Antibacterial effects of Kampo products against pneumonia causative bacteria

Community-acquired pneumonia is caused primarily by bacterial infection. For years, antibiotic treatment has been the standard of care for patients with bacterial pneumonia, although the emergence of antimicrobial-resistant strains is recognized as a global health issue. The traditional herbal medicine Kampo has a long history of clinical use and is relatively safe in treating various diseases. However, the antimicrobial effects of Kampo products against pneumonia-causative bacteria remain largely uncharacterized. In this study, we investigated the bacteriological efficacy of 11 Kampo products against bacteria commonly associated with pneumonia. Sho-saiko-To (9), Sho-seiryu-To (19), Chikujo-untan-To (91) and Shin'i-seihai-To (104) inhibited the growth of S. pneumoniae serotype 3, a highly virulent strain that causes severe pneumonia. Also, the growth of S. pneumoniae serotype 1, another highly virulent strain, was suppressed by treatment with Sho-saiko-To (9), Chikujo-untan-To (91), and Shin'i-seihai-To (104). Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against these strains ranged from 6.25-50 mg/mL and 12.5-25 mg/mL, respectively. Furthermore, Sho-saiko-To (9), Chikujo-untan-To (91), and Shin'i-seihai-To (104) suppressed the growth of antibiotic-resistant S. pneumoniae isolates. Additionally, Sho-saiko-To (9) and Shin'i-seihai-To (104) showed growth inhibition activity against Staphylococcus aureus, another causative agent for pneumonia, with MIC ranging from 6.25-12.5 mg/mL. These results suggest that some Kampo products have antimicrobial effects against S. pneumoniae and S. aureus, and that Sho-saiko-To (9) and Shin'i-seihai-To (104) are promising medicines for treating pneumonia caused by S. pneumoniae and S. aureus infection.

Current Diagnostic Techniques for Pneumonia: A Scoping Review

Community-acquired pneumonia is one of the most lethal infectious diseases, especially for infants and the elderly. Given the variety of causative agents, the accurate early detection of pneumonia is an active research area. To the best of our knowledge, scoping reviews on diagnostic techniques for pneumonia are lacking. In this scoping review, three major electronic databases were searched and the resulting research was screened. We categorized these diagnostic techniques into four classes (i.e., lab-based methods, imaging-based techniques, acoustic-based techniques, and physiological-measurement-based techniques) and summarized their recent applications. Major research has been skewed towards imaging-based techniques, especially after COVID-19. Currently, chest X-rays and blood tests are the most common tools in the clinical setting to establish a diagnosis; however, there is a need to look for safe, non-invasive, and more rapid techniques for diagnosis. Recently, some non-invasive techniques based on wearable sensors achieved reasonable diagnostic accuracy that could open a new chapter for future applications. Consequently, further research and technology development are still needed for pneumonia diagnosis using non-invasive physiological parameters to attain a better point of care for pneumonia patients.

Investigating causal associations between pneumonia and lung cancer using a bidirectional mendelian randomization framework

BACKGROUND

Pneumonia and lung cancer are both major respiratory diseases, and observational studies have explored the association between their susceptibility. However, due to the presence of potential confounders and reverse causality, the comprehensive causal relationships between pneumonia and lung cancer require further exploration.

METHODS

Genome-wide association study (GWAS) summary-level data were obtained from the hitherto latest FinnGen database, COVID-19 Host Genetics Initiative resource, and International Lung Cancer Consortium. We implemented a bidirectional Mendelian randomization (MR) framework to evaluate the causal relationships between several specific types of pneumonia and lung cancer. The causal estimates were mainly calculated by inverse-variance weighted (IVW) approach. Additionally, sensitivity analyses were also conducted to validate the robustness of the causalty.

RESULTS

In the MR analyses, overall pneumonia demonstrated a suggestive but modest association with overall lung cancer risk (Odds ratio [OR]: 1.21, 95% confidence interval [CI]: 1.01 - 1.44, P = 0.037). The correlations between specific pneumonia types and overall lung cancer were not as significant, including bacterial pneumonia (OR: 1.07, 95% CI: 0.91 - 1.26, P = 0.386), viral pneumonia (OR: 1.00, 95% CI: 0.95 - 1.06, P = 0.891), asthma-related pneumonia (OR: 1.18, 95% CI: 0.92 - 1.52, P = 0.181), and COVID-19 (OR: 1.01, 95% CI: 0.78 - 1.30, P = 0.952). Reversely, with lung cancer as the exposure, we observed that overall lung cancer had statistically crucial associations with bacterial pneumonia (OR: 1.08, 95% CI: 1.03 - 1.13, P = 0.001) and viral pneumonia (OR: 1.09, 95% CI: 1.01 - 1.19, P = 0.037). Sensitivity analysis also confirmed the robustness of these findings.

CONCLUSION

This study has presented a systematic investigation into the causal relationships between pneumonia and lung cancer subtypes. Further prospective study is warranted to verify these findings.

Melatonin-induced upregulation of telomerase activity interferes with macrophage mitochondrial metabolism and suppresses NLRP3 inflammasome activation in the treatment of Pneumonia

Objective

This study aims to investigate the effects of melatonin-induced upregulation of telomerase activity on mitochondrial metabolism and NLRP3 inflammasome activation in macrophages, with the ultimate goal of elucidating potential therapeutic implications for pneumonia treatment.

Materials and methods

Macrophages were treated with melatonin to assess its impact on telomerase activity. Mitochondrial function was evaluated through the measurement of reactive oxygen species (ROS) levels and cellular energy production. NLRP3 inflammasome activation was assessed by examining the production of inflammatory cytokines, such as interleukin-1β (IL-1β). The expression levels of key proteins involved in mitochondrial metabolism and NLRP3 inflammasome signaling were also analyzed.

Results

Our findings demonstrated that melatonin treatment significantly upregulated telomerase activity in macrophages. This was associated with a reduction in ROS levels and enhanced cellular energy production, indicating improved mitochondrial function. Moreover, melatonin treatment suppressed NLRP3 inflammasome activation, resulting in reduced secretion of IL-1β. The expression levels of proteins involved in mitochondrial metabolism and NLRP3 inflammasome signaling were modulated by melatonin.

Conclusion

These results suggest that melatonin-induced upregulation of telomerase activity can interfere with mitochondrial metabolism and inhibit NLRP3 inflammasome activation in macrophages. This indicates a potential therapeutic role for melatonin in the treatment of pneumonia. Understanding the molecular mechanisms underlying these effects may lead to the development of novel therapeutic strategies targeting mitochondria and NLRP3 inflammasome activation for the management of pneumonia. Further investigations are warranted to fully uncover the therapeutic potential of melatonin and its implications for pneumonia treatment.

Accuracy of Thoracic Ultrasonography for the Diagnosis of Pediatric Pneumonia: A Systematic Review and Meta-Analysis

As an emerging imaging technique, thoracic ultrasonography (TUS) is increasingly utilized in the diagnosis of lung diseases in children and newborns, especially in emergency and critical settings. This systematic review aimed to estimate the diagnostic accuracy of TUS in childhood pneumonia. We searched Embase, PubMed, and Web of Science for studies until July 2023 using both TUS and chest radiography (CR) for the diagnosis of pediatric pneumonia. Two researchers independently screened the literature based on the inclusion and exclusion criteria, collected the results, and assessed the risk of bias using the Diagnostic Accuracy Study Quality Assessment (QUADAS) tool. A total of 26 articles met our inclusion criteria and were included in the final analysis, including 22 prospective studies and four retrospective studies. The StataMP 14.0 software was used for the analysis of the study. The overall pooled sensitivity was 0.95 [95% confidence intervals (CI), 0.92-0.97] and the specificity was 0.94 [95% CI, 0.88-0.97], depicting a good diagnostic accuracy. Our results indicated that TUS was an effective imaging modality for detecting pediatric pneumonia. It is a potential alternative to CXR and a follow-up for pediatric pneumonia due to its simplicity, versatility, low cost, and lack of radiation hazards.

A Review of the Resistance Mechanisms for β-Lactams, Macrolides and Fluoroquinolones among Streptococcus pneumoniae

Streptococcus pneumoniae (S. pneumoniae) is a bacterial species often associated with the occurrence of community-acquired pneumonia (CAP). CAP refers to a specific kind of pneumonia that occurs in individuals who acquire the infection outside of a healthcare setting. It represents the leading cause of both death and morbidity on a global scale. Moreover, the declaration of S. pneumoniae as one of the 12 leading pathogens was made by the World Health Organization (WHO) in 2017. Antibiotics like β-lactams, macrolides, and fluoroquinolones are the primary classes of antimicrobial medicines used for the treatment of S. pneumoniae infections. Nevertheless, the efficacy of these antibiotics is diminishing as a result of the establishment of resistance in S. pneumoniae against these antimicrobial agents. In 2019, the WHO declared that antibiotic resistance was among the top 10 hazards to worldwide health. It is believed that penicillin-binding protein genetic alteration causes β-lactam antibiotic resistance. Ribosomal target site alterations and active efflux pumps cause macrolide resistance. Numerous factors, including the accumulation of mutations, enhanced efflux mechanisms, and plasmid gene acquisition, cause fluoroquinolone resistance. Furthermore, despite the advancements in pneumococcal vaccinations and artificial intelligence (AI), it is not feasible for individuals to rely on them indefinitely. The ongoing development of AI for combating antimicrobial resistance necessitates more research and development efforts. A few strategies can be performed to curb this resistance issue, including providing educational initiatives and guidelines, conducting surveillance, and establishing new antibiotics targeting another part of the bacteria. Hence, understanding the resistance mechanism of S. pneumoniae may aid researchers in developing a more efficacious antibiotic in future endeavors.

Impact of Angiotensin Receptor Blockers Use on In-Hospital Mortality in Community-Acquired Pneumonia Patients with Hypertension

Introduction

This study aimed to explore the association of angiotensin receptor blockers (ARBs) use with in-hospital mortality among Chinese patients with hypertension hospitalized with community-acquired pneumonia (CAP).

Methods

This study was conducted from January 2014 to January 2017, and data from patients with hypertension hospitalized with CAP were analyzed retrospectively. Multivariable logistic regression and propensity score matching (PSM) were used to investigate any association.

Results

1,510 patients were included in this study. The crude in-hospital mortality was significantly lower in patients with ARBs use (4.2% vs. 12.5%, p < 0.001). In the extended multivariable logistic models, the odds ratios (ORs) of ARBs use were consistently significant in all six models (OR range 0.27-0.48, p < 0.05 for all). After subgroup analysis, ARBs use remained a potentially protective factor against in-hospital mortality, and no interaction was detected. After PSM, the in-hospital mortality remained significantly lower in the ARBs use group (4.2% vs. 10.9%, p = 0.002). In the univariate analysis, using ARBs was associated with in-hospital mortality (PSM OR, 0.36; 95% CI, 0.19-0.68; p = 0.002). Additionally, compared with the control group, ARBs use did not significantly increase the risk of acute kidney injury (12.4% vs. 10.9%, p = 0.628), renal replacement therapy (0.6% vs. 0.3%, p = 1.000), and hyperkalemia (1.8% vs. 2.1%, p = 1.000).

Conclusion

Although residual confounding cannot be excluded, the use of ARBs was associated with lower in-hospital mortality in Chinese patients with hypertension hospitalized with CAP.

Trends of legionellosis reported in Jeju Province, Republic of Korea, 2015-2022

BACKGROUND

The number of reported cases of Legionnaires' disease (LD) in the Republic of Korea surged nationally in 2016; however, in 2022, this number was higher in Jeju Province than the previous national peak. A descriptive epidemiological study was conducted to analyze trends in the incidence of reported LD cases in Jeju Island from 2015 to 2022.

METHODS

The data for this study were obtained from case reports submitted to the Korea Disease Control and Prevention Agency through its Disease and Health Integrated Management System. The selection criteria were cases or suspected cases of LD reported among Jeju residents between 2015 and 2022. The 95% confidence interval of the crude incidence rate was calculated using the Poisson distribution.

RESULTS

Since 2020, the incidence rate of LD in Jeju has risen sharply, showing a statistically significant difference from the national incidence rate. A particular medical institution in Jeju reported a significant number of LD cases. Screening with the urine antigen test (UAT) also increased significantly.

CONCLUSION

Our findings indicate that the rapid increase in cases of LD in Jeju Province since 2020 was due to the characteristics of medical-care use among Jeju residents, which were focused on a specific medical institution. According to their clinical practice guidelines, this medical institution conducted UATs to screen patients suspected of pneumonia.

Differential metabolic host response to pathogens associated with community-acquired pneumonia

Background

Metabolic changes induced by the host immune response to pathogens found in patients with community-acquired pneumonia (CAP) may provide insight into its pathogenesis. In this study, we characterized differences in the host metabolic response to common CAP-associated pathogens.

Method

Targeted metabolomic profiling was performed on serum samples obtained from hospitalized CAP patients (n = 119) at admission. We quantified 347 unique metabolites across multiple biochemical classes, including amines, acylcarnitines, and signaling lipids. We evaluated if unique associations between metabolite levels and specific CAP-associated pathogens could be identified.

Results

Several acylcarnitines were found to be elevated in C. burnetii and herpes simplex virus and lowered in M. pneumoniae as compared to other pathogens. Phenylalanine and kynurenine were found elevated in L. pneumophila as compared to other pathogens. S-methylcysteine was elevated in patients with M. pneumoniae, and these patients also showed lowered cortisol levels in comparison to almost all other pathogens. For the herpes simplex virus, we observed a unique elevation of eicosanoids and several amines. Many lysophosphatidylcholines showed an altered profile in C. burnetii versus S. pneumoniae, L. pneumophila, and respiratory syncytial virus. Finally, phosphatidylcholines were negatively affected by the influenza virus in comparison to S. pneumoniae.

Conclusions

In this exploratory analysis, metabolites from different biochemical classes were found to be altered in serum samples from patients with different CAP-associated pathogens, which may be used for hypothesis generation in studies on differences in pathogen host response and pathogenesis of CAP.

Effect of diagnosis level of certainty on adherence to antibiotics' guidelines in ED patients with pneumonia: a post-hoc analysis of an interventional trial

BACKGROUND AND IMPORTANCE

Clinical diagnosis of community-acquired pneumonia (CAP) is difficult to establish with certainty. Adherence to antibiotic guidelines independently affects the prognosis of CAP patients.

OBJECTIVE

We aimed to determine whether guidelines' adherence was related to CAP diagnosis level of certainty and could be reinforced accordingly to diagnosis improvement.

DESIGN

Secondary analysis of a prospective, multicenter study, which evaluated the impact of early thoracic CT scan on diagnosis and therapeutic plan in patients with clinically suspected CAP visiting emergency departments.

SETTING AND PARTICIPANTS

In total 319 patients with clinically suspected CAP were enrolled in four emergency departments, Paris, France, between Nov 2011 and Jan 2013.

OUTCOME MEASURES AND ANALYSIS

We evaluated guidelines' adherence before and after CT scan and its relationship with CAP diagnosis level of certainty. Antibiotics were categorized as adherent according to 2010 French guidelines. CAP diagnosis level of certainty was prospectively classified by the emergency physicians based on a Likert scale as excluded, possible, probable or definite before and immediately after the CT scan. These classifications and therapeutic plans were also completed by an independent adjudication committee. Determinants of adherence were assessed using Poisson regression with robust variance.

MAIN RESULTS

Adherence to guidelines increased from 34.2% before CT scan to 51.3% after CT scan [difference 17.1% (95% CI, 9.5-24.7)], meanwhile CAP diagnosis with high level of certainty (definite and excluded CAP) increased from 46.1 to 79.6% [difference 33.5% (95% CI, 26.5-40.5)]. Diagnosis level of certainty before CT scan was the strongest determinant of adherence in multivariate analysis (RR, 2.63; 95% CI, 1.89-3.67).

CONCLUSION

Antibiotic guidelines' adherence was poor and positively related to CAP diagnosis level of certainty. The results suggest that improvements in CAP diagnosis may increase adherence to antibiotic guidelines. Clinical trial registered with www.clinicaltrials.gov (NCT01574066).

A Nomogram for Early Diagnosis of Community-Acquired Pneumonia Based on Bronchoalveolar Lavage Fluid Metabolomics

Purpose

There is a high disease burden associated with community-acquired pneumonia (CAP) around the world. A timely and correct diagnosis of CAP can facilitate early treatment and prevent illness progression. The present study aimed to find some novel biomarkers of CAP by metabolic analysis and construct a nomogram model for precise diagnosis and individualized treatment of CAP patients.

Patients and Methods

42 CAP patients and 20 controls were enrolled in this study. The metabolic profiles of bronchoalveolar lavage fluid (BALF) samples were identified by untargeted LC-MS/MS analysis. With a VIP score ≥ 1 in OPLS-DA analysis and P < 0.05, the significantly dysregulated metabolites were estimated as potential biomarkers of CAP, which were further included in the construction of the diagnostic prediction model along with laboratory inflammatory indexes via stepwise backward regression analysis. Discrimination, calibration, and clinical applicability of the nomogram were evaluated by the C-index, the calibration curve, and the decision curve analysis (DCA) estimated by bootstrap resampling.

Results

The metabolic profiles differed obviously between CAP patients and healthy controls, as shown by PCA and OPLS-DA plots. Seven metabolites significantly dysregulated in CAP were established: dimethyl disulfide, oleic acid (d5), N-acetyl-a-neuraminic acid, pyrimidine, choline, LPC (12:0/0:0) and PA (20:4/2:0). Multivariate logistic regression revealed that the expression levels of PA (20:4/2:0), N-acetyl-a-neuraminic acid, and CRP were associated with CAP. After being validated by bootstrap resampling, this model showed satisfactory diagnostic performance.

Conclusion

A novel nomogram prediction model containing metabolic potential biomarkers in BALF that was developed for the early diagnosis of CAP offers insights into the pathogenesis and host response in CAP.

C-Reactive Protein as a Predictor of Survival and Length of Hospital Stay in Community-Acquired Pneumonia

Introduction: Community-acquired pneumonia (CAP) presents high mortality rates and high healthcare costs worldwide. C-reactive protein (CRP) has been widely used as a biomarker for the management of CAP. We evaluated the performance of CRP threshold values and ΔCRP as predictors of CAP survival and length of hospital stay. Methods: A total of 173 adult patients with CAP were followed for up to 30 days. We measured serum CRP levels on days 1, 4, and 7 (D1, D4, and D7) of hospitalization, and their variations between different days were calculated (ΔCRP). A multivariate logistic regression model was created with CAP 30-day survival and length of hospital stay as dependent variables, and absolute CRP values and ΔCRP, age, sex, smoking habit (pack-years), pO2/FiO2 ratio on D1, WBC on D1, and CURB-65 score as independent variables. Results: A total of six patients with CAP died (30-day mortality 3.47%). No difference was found in CRP levels and ΔCRP between survivors and non-survivors. Using a cut-off level of 9 mg/dL, the AUC (95% CI) for the prediction of survival of CRP on D4 and D7 were 0.765 (0.538−0.992) and 0.784 (0.580−0.989), respectively. A correlation between CRP values on any day and length of hospital stay was found, with it being stronger for CRPD4 and CRPD7 (p < 0.0001 and p = 0.0024, respectively). A reduction of CRP > 50% from D1 to D4 was associated with 4.11 fewer days of hospitalization (p = 0.0308). Conclusions: CRP levels on D4 and D7, but not ΔCRP, could fairly predict CAP survival. A reduction of CRP > 50% by the fourth day of hospitalization could predict a shorter hospital stay.

N-myc and STAT interactor is a novel biomarker of severity in community-acquired pneumonia: a prospective study

Objectives

To tested the ability of N-myc and STAT interactor (NMI) levels in patients with community-acquired pneumonia (CAP) to predict the severity of the disease.

Methods

Prospective observational analysis of patients with CAP was performed. The NMI levels in serum of 394 CAP patients on admission were measured by immunoassay. Thirty-day mortality and intensive care unit (ICU) admission were set as clinical outcomes. The predicting value of NMI for clinical outcomes was determined by receiver operating characteristic curve and logistic regression analysis. The internal validity was assessed using cross-validation with bootstrap resampling.

Results

NMI was an independent risk factor for both 30-day mortality and admission to ICU for CAP patients. The area under curve (AUC) of NMI to predict mortality was 0.91 (95% CI: 0.86–0.96), and that to predict ICU admission was 0.92 (95% CI: 0.88–0.97), significantly higher than that of other biomarkers including procalcitonin and C-reactive protein. The proportion of clinical outcomes notably rose as NMI levels elevated (P < 0.001). The AUCs of the new score systems including NMI (N-PSI and N-CURB65 score) to predict outcomes were significantly higher than the original score systems.

Conclusions

NMI is a novel biomarker for predicting CAP severity superior to former biomarkers in 30-day mortality and ICU admission.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-02139-x.

Antibacterial Activity of Electrospun Polyacrylonitrile Copper Nanoparticle Nanofibers on Antibiotic Resistant Pathogens and Methicillin Resistant Staphylococcus aureus (MRSA)

Bacteria induced diseases such as community-acquired pneumonia (CAP) are easily transmitted through respiratory droplets expelled from a person’s nose or mouth. It has become increasingly important for researchers to discover materials that can be implemented in in vitro surface contact settings which disrupt bacterial growth and transmission. Copper (Cu) is known to have antibacterial properties and have been used in medical applications. This study investigates the antibacterial properties of polyacrylonitrile (PAN) based nanofibers coated with different concentrations of copper nanoparticles (CuNPs). Different concentrations of copper sulfate (CuSO₄) and polyacrylonitrile (PAN) were mixed with dimethylformamide (DMF) solution, an electrospinning solvent that also acts as a reducing agent for CuSO₄, which forms CuNPs and Cu ions. The resulting colloidal solutions were electrospun into nanofibers, which were then characterized using various analysis techniques. Methicillin-Resistant isolates of Staphylococcus aureus, an infective strain that induces pneumonia, were incubated with cutouts of various nanocomposites using disk diffusion methods on Luria-Bertani (LB) agar to test for the polymers’ antibacterial properties. Herein, we disclose that PAN-CuNP nanofibers have successfully demonstrated antibacterial activity against bacteria that were otherwise resistant to highly effective antibiotics. Our findings reveal that PAN-CuNP nanofibers have the potential to be used on contact surfaces that are at risk of contracting bacterial infections, such as masks, in vivo implants, or surgical intubation.

Contribution of clinical severity and geriatric risk factors in predicting short-term mortality of older hospitalized pneumonia patients: the Pneumonia in Italian Acute Care for Elderly units (PIACE) study

BACKGROUND

Clinical severity of pneumonia in older persons increases the risk for short-term mortality. Comprehensive geriatric assessment (CGA) may provide further insight in prognostic stratification.

AIMS

To investigate whether CGA may improve prognostic stratification among older patients with pneumonia admitted to hospital.

METHODS

Our series consisted of 318 consecutive patients hospitalized for pneumonia in a multicenter observational study. Disease severity was assessed by Sequential Organ Failure Assessment (SOFA) and Pneumonia Severity Index (PSI). CGA included the occurrence of delirium, Basic Activities of Daily Living (BADL) disability, cognitive impairment at Short Portable Mental Status Questionnaire (SPMSQ) and overall comorbidity assessed by Cumulative Illness Rating Scale (CIRS). The outcomes were in-hospital and post-discharge 3 month mortality. Statistical analysis was carried out by Cox regression, area under receiver operating curve (AUC) and net reclassification index (NRI).

RESULTS

Overall, 53 patients died during hospitalization and 52 after discharge. Delirium, SOFA score and admission BADL disability were significant predictors of in-hospital mortality. SOFA score, CIRS, previous long-term oxygen therapy and discharge BADL dependency significantly predicted post-discharge mortality. The accuracy of SOFA in predicting in-hospital and post-discharge mortality was fair (AUC = 0.685, 95% CI = 0.610-0.761 and AUC = 0.663, 95% CI = 0.593-0.734, respectively). BADL dependency and delirium improved predictive accuracy for in-hospital mortality (ΔAUC = 0.144, 95% CI = 0.062-0.227, p < 0.001), while pre-admission oxygen therapy, CIRS and BADL dependency improved predictivity for 3 month mortality (ΔAUC = 0.177, 95% CI = 0.102-0.252, p < 0.001).

DISCUSSION

Among older pneumonia patients, prognostic stratification obtained by clinical severity indexes is significantly improved by CGA risk factors.

CONCLUSIONS

CGA provides important information for prognostic stratification and clinical management of older pneumonia patients.

Clinical Characteristics of COVID-19 Patients and Application to an Artificial Intelligence System for Disease Surveillance

During the coronavirus disease (COVID-19) pandemic, we admitted suspected or confirmed COVID-19 patients to our isolation wards between 2 March 2020 and 4 May 2020, following a well-designed and efficient assessment protocol. We included 217 patients suspected of COVID-19, of which 27 had confirmed COVID-19. The clinical characteristics of these patients were used to train artificial intelligence (AI) models such as support vector machine (SVM), decision tree, random forest, and artificial neural network for diagnosing COVID-19. When analyzing the performance of the models, SVM showed the highest sensitivity (SVM vs. decision tree vs. random forest vs. artificial neural network: 100% vs. 42.86% vs. 28.57% vs. 71.43%), while decision tree and random forest had the highest specificity (SVM vs. decision tree vs. random forest vs. artificial neural network: 88.37% vs. 100% vs. 100% vs. 94.74%) in the diagnosis of COVID-19. With the aid of AI models, physicians may identify COVID-19 patients earlier, even with few baseline data available, and segregate infected patients earlier to avoid hospital cluster infections and to ensure the safety of medical professionals and ordinary patients in the hospital.

Myotubularin-related protein protects against neuronal degeneration mediated by oxidative stress or infection

Microbial infections have been linked to the onset and severity of neurodegenerative diseases such as amyotrophic lateral sclerosis, multiple sclerosis, Alzheimer's disease, but the underlying mechanisms remain largely unknown. Here, we used a genetic screen for genes involved in protection from infection-associated neurodegeneration and identified the gene mtm-10. We then validated the role of the encoded myotubularin-related protein, MTM-10, in protecting the dendrites of Caenorhabditis elegans from degeneration mediated by oxidative stress or Pseudomonas aeruginosa infection. Further experiments indicated that mtm-10 is expressed in the AWC neurons of C. elegans, where it functions in a cell-autonomous manner to protect the dendrite degeneration caused by pathogen infection. We also confirm that the changes observed in the dendrites of the animals were not because of premature death or overall sickness. Finally, our studies indicated that mtm-10 functions in AWC neurons to preserve chemosensation after pathogen infection. These results reveal an essential role for myotubularin-related protein 10 in the protection of dendrite morphology and function against the deleterious effects of oxidative stress or infection.

An immunoinformatics-based designed multi-epitope candidate vaccine (mpme-VAC/STV-1) against Mycoplasma pneumoniae

Pneumonia is a serious global health problem that accounts for over one million deaths annually. Among the main microorganisms causing pneumonia, Mycoplasma pneumoniae is one of the most common ones for which a vaccine is immediately required. In this context, a multi-epitope vaccine against this pathogen could be the best option that can induce effective immune response avoiding any serious adverse reactions. In this study, using an immunoinformatics approach we have designed a multi-epitope vaccine (mpme-VAC/STV-1) against M. pneumoniae. Our designed mpme-VAC/STV-1 is constructed using CTL (cytotoxic T lymphocyte), HTL (Helper T lymphocyte), and B-cell epitopes. These epitopes are selected from the core proteins of 88 M. pneumoniae genomes that were previously identified through reverse vaccinology approaches. The epitopes were filtered according to their immunogenicity, population coverage, and several other criteria. Sixteen CTL/B- and thirteen HTL/B- epitopes that belong to 5 core proteins were combined together through peptide linkers to develop the mpme-VAC/STV-1. The heat-labile enterotoxin from E. coli was used as an adjuvant. The designed mpme-VAC/STV-1 is predicted to be stable, non-toxic, non-allergenic, non-host homologous, and with required antigenic and immunogenic properties. Docking and molecular dynamic simulation of mpme-VAC/STV-1 shows that it can stimulate TLR2 pathway mediated immunogenic reactions. In silico cloning of mpme-VAC/STV-1 in an expression vector also shows positive results. Finally, the mpme-VAC/STV-1 also shows promising efficacy in immune simulation tests. Therefore, our constructed mpme-VAC/STV-1 could be a safe and effective multi-epitope vaccine for immunization against pneumonia. However, it requires further experimental and clinical validations.

Development and validation of a new scoring system for prognostic prediction of community-acquired pneumonia in older adults

The discriminative power of CURB-65 for mortality in community-acquired pneumonia (CAP) is suspected to decrease with age. However, a useful prognostic prediction model for older patients with CAP has not been established. This study aimed to develop and validate a new scoring system for predicting mortality in older patients with CAP. We recruited two prospective cohorts including patients aged ≥ 65 years and hospitalized with CAP. In the derivation (n = 872) and validation cohorts (n = 1,158), the average age was 82.0 and 80.6 years and the 30-day mortality rate was 7.6% (n = 66) and 7.4% (n = 86), respectively. A new scoring system was developed based on factors associated with 30-day mortality, identified by multivariate analysis in the derivation cohort. This scoring system named CHUBA comprised five variables: confusion, hypoxemia (SpO₂ ≤ 90% or PaO₂ ≤ 60 mmHg), blood urea nitrogen ≥ 30 mg/dL, bedridden state, and serum albumin level ≤ 3.0 g/dL. With regard to 30-day mortality, the area under the receiver operating characteristic curve for CURB-65 and CHUBA was 0.672 (95% confidence interval, 0.607–0.732) and 0.809 (95% confidence interval, 0.751–0.856; P < 0.001), respectively. The effectiveness of CHUBA was statistically confirmed in the external validation cohort. In conclusion, a simpler novel scoring system, CHUBA, was established for predicting mortality in older patients with CAP.

Association between neutrophil to lymphocyte ratio and mortality among community acquired pneumonia patients: a meta-analysis

The neutrophil to lymphocyte ratio (NLR)is an emerging biomarker used in the prognosis of many conditions. We aimed to conduct a meta-analysis to assess the prognostic accuracy of the NLR in determining mortality in patients with Community acquired pneumonia (CAP). The Pubmed, EBSCO, and Scopus databases were searched to find all relevant articles. 10 articles with 5220 patients were included. The pooled area under the curve (AUC) of NLR admission levels to predict 30-Day mortality of CAP patients was 0.706; 95% CI (0.631 to 0.781), while the pooled AUC of NLR levels taken at 3-5 days was 0.882; 95% CI (0.818 to 0.945). Meta analysis also showed a significant difference in the NLR between the Survivors and 30-Day non-survivors. This difference was greater when NLR levels were taken at 3-5 days; Standardized mean difference (SMD) = 1.646; 95% CI (0.451 to 2.840) compared to NLR levels at admission SMD = 1.139; 95% CI (0.514 to 1.764). These results show that the NLR has potential to be incorporated in the routine assessment and stratification of CAP patients, especially in the early-stage evolution (3-5 days), keeping in mind the availability and cost effectiveness of this test.

Towards Understanding COVID-19: Molecular Insights, Co-infections, Associated Disorders, and Aging

BACKGROUND

COVID-19 can be related to any diseases caused by microbial infection(s) because 1) co-infection with COVID-19-related virus and other microorganism(s) and 2) because metabolites produced by microorganisms such as bacteria, fungi, and protozoan can be involved in necrotizing pneumonia and other necrotizing medical conditions observed in COVID-19.

OBJECTIVE

By way of illustration, the microbial metabolite of aromatic amino acid tryptophan, a biogenic amine tryptamine inducing neurodegeneration in cell and animal models, also induces necrosis.

METHODS

This report includes analysis of COVID-19 positivity by zip codes in Florida and relation of the positivity to population density, possible effect of ecological and social factors on spread of COVID-19, autopsy analysis of COVID-19 cases from around the world, serum metabolomics analysis, and evaluation of autoantigenome related to COVID-19.

RESULTS

In the present estimations, COVID-19 positivity percent per zip code population varied in Florida from 4.65% to 44.3% (February 2021 data). COVID-19 analysis is partially included in my book Microbial Metabolism and Disease (2021). The autoantigenome related to COVID-19 is characterized by alterations in protein biosynthesis proteins including aminoacyl-tRNA synthetases. Protein biosynthesis alteration is a feature of Alzheimer's disease. Serum metabolomics of COVID-19 positive patients show alteration in shikimate pathway metabolism, which is associated with the presence of Alzheimer's disease-associated human gut bacteria.

CONCLUSION

Such alterations in microbial metabolism and protein biosynthesis can lead to toxicity and neurodegeneration as described earlier in my book Protein Biosynthesis Interference in Disease (2020).

Controlling Nutritional Status score: A novel prognostic marker for patients with community-acquired pneumonia

Objective:

We aimed to investigate the prevalence and prognostic value of malnutrition assessed by Controlling Nutritional Status score in community-acquired pneumonia patients.

Methods:

All adult patients admitted to our emergency department and hospitalized for community-acquired pneumonia were prospectively followed-up until hospital discharge or death. Nutritional status was assessed with the Controlling Nutritional Status score, which is based on serum albumin levels, total cholesterol levels, and lymphocyte counts. The primary study endpoint was complicated hospital course defined as need for mechanical ventilation, mortality, or intensive care unit admission.

Results:

Three hundred and five patients (mean age 68.6 ± 11.2 years and 51.8% female) were enrolled, and 40 patients (13.1%) had complicated hospitalizations. Older patients, patients with more comorbidities, and patients with higher Controlling Nutritional Status scores on admission were tended to have a higher rate of complications during their hospitalization. Multivariate analysis showed that older age (odds ratio 2.55, 95% confidence interval 1.41–4.64, p < 0.001), presence of diabetes (odds ratio 1.54; 95% confidence interval 1.09–3.65; p = 0.004), pneumonia severity index ⩾ 3 (odds ratio 1.27, 95% confidence interval 0.524–3.725, p = 0.035), and Controlling Nutritional Status score > 4 (odds ratio 2.23, 95% confidence interval 1.129–3.657, p = 0.001) were independent predictors of complicated hospitalizations.

Conclusion:

Malnutrition determined by Controlling Nutritional Status score predicts complications in hospitalized patients with community-acquired pneumonia.

Metabolomic profiling of microbial disease etiology in community-acquired pneumonia

Diagnosis of microbial disease etiology in community-acquired pneumonia (CAP) remains challenging. We undertook a large-scale metabolomics study of serum samples in hospitalized CAP patients to determine if host-response associated metabolites can enable diagnosis of microbial etiology, with a specific focus on discrimination between the major CAP pathogen groups S. pneumoniae, atypical bacteria, and respiratory viruses. Targeted metabolomic profiling of serum samples was performed for three groups of hospitalized CAP patients with confirmed microbial etiologies: S. pneumoniae (n = 48), atypical bacteria (n = 47), or viral infections (n = 30). A wide range of 347 metabolites was targeted, including amines, acylcarnitines, organic acids, and lipids. Single discriminating metabolites were selected using Student’s T-test and their predictive performance was analyzed using logistic regression. Elastic net regression models were employed to discover metabolite signatures with predictive value for discrimination between pathogen groups. Metabolites to discriminate S. pneumoniae or viral pathogens from the other groups showed poor predictive capability, whereas discrimination of atypical pathogens from the other groups was found to be possible. Classification of atypical pathogens using elastic net regression models was associated with a predictive performance of 61% sensitivity, 86% specificity, and an AUC of 0.81. Targeted profiling of the host metabolic response revealed metabolites that can support diagnosis of microbial etiology in CAP patients with atypical bacterial pathogens compared to patients with S. pneumoniae or viral infections.

Mid-Regional Proadrenomedullin and Mid-Regional Proatrial Natriuretic Peptide Clearance Predicts Poor Outcomes Better Than Single Baseline Measurements in Critically Ill Patients With Pneumonia: A Retrospective Cohort Study

Background We assessed the ability of baseline and serial measurements of mid-regional proadrenomedullin (MR-proADM) and mid-regional proatrial natriuretic peptide (MR-proANP) to predict 28-day mortality in critically ill patients with pneumonia compared with Acute Physiological and Chronic Health Evaluation IV (APACHE IV) model and Sequential Organ Failure Assessment (SOFA) score. Methodology Biomarkers were collected for the first five days in this retrospective observational cohort study. Biomarker clearance (as a percentage) was presented as biomarker decline in five days. We investigated the relationship between biomarkers and mortality in a multivariable Cox regression model. APACHE IV and SOFA were calculated after 24 hours from intensive care unit admission. Results In 153 critically ill patients with pneumonia, 28-day mortality was 26.8%. Values of baseline MR-proADM, MR-proANP, and APACHE IV were significantly higher in 28-day nonsurvivors, but not significantly different for SOFA score. Baseline MR-proADM and MR-proANP, APACHE IV, and SOFA had a low area under the curve in receiver operating characteristics (ROC) curves. No optimal cut-off points could be calculated. Biomarkers and severity scores were divided into tertiles. The highest tertiles baseline MR-proADM and MR-proANP were not significant predictors for 28-day mortality in a multivariable model with age and APACHE IV. SOFA was not a significant predictor in univariable analysis. Clearances of MR-proADM and MR-proANP were significantly higher in 28-day survivors. MR-proADM and MR-proANP clearances had similar low accuracy to identify nonsurvivors in ROC curves and were divided into tertiles. Low clearances of MR-proADM and MR-proANP (first tertiles) were significant predictors for 28-day mortality (hazard ratio [HR]: 2.38; 95% confidence interval [CI]: 1.21-4.70; p = 0.013 and HR: 2.27; 95% CI: 1.16-4.46; p = 0.017) in a model with age and APACHE IV. Conclusions MR-proADM and MR-proANP clearance performed better in predicting 28-day mortality in a model with age and APACHE IV compared with single baseline measurements in a mixed population of critically ill with pneumonia.

Community-acquired pneumonia: similarities and differences between European and American guidelines - A narrative review

Community-acquired pneumonia (CAP) is severe disease. Early prescription of an adequate treatment has a positive impact in the CAP outcome. Despite the evidence of existing relevant differences between CAP across geographical areas, general guidelines can be designed to be applied everywhere. Eight years have passed between the publication of the European (EG) and American (AG) CAP guidelines, thus the aim of this narrative review is to compare both guidelines and summarize their recommendations. The main similarity between both guidelines is the antibiotics recommendation with the exception that AG mention new antimicrobials that were not available at the time of EG publication. Both guidelines recommend against routinely adding steroids as an adjuvant treatment. Finally, both guidelines acknowledge that the decision to hospitalize a patient is clinical and should be complemented with an objective tool for risk assessment. EG recommend the CRB-65 while AG recommend the Pneumonia Severity Index (PSI). EG and AG share a similar core of recommendations and only differ in minor issues such as new antibiotics. Likewise, both guidelines recommend against the routine prescription of steroids as an adjuvant therapy.

Nefer, Sinuhe and clinical research assessing post COVID-19 condition

In the immortal classical novel by Finnish writer Mika Waltari (1908–1979) (figure 1), Nefer, a beautiful and cunning Egyptian courtesan, seduces and befools Sinuhe, the pharaoh's physician. Sinuhe is bewitched by her charms and sacrifices everything for her – even his parents’ house and grave – only to be cruelly rejected when Nefer tires of playing with him.

Clinical research studies reporting on post COVID-19 condition should follow some basic recommendations http://bit.ly/3h4OEIa

Acute cardiovascular events in patients with community acquired pneumonia: results from the observational prospective FADOI-ICECAP study

Background

The burden of cardiovascular (CV) complications in patients hospitalised for community-acquired pneumonia (CAP) is still uncertain. Available studies used different designs and different criteria to define CV complications. We assessed the cumulative incidence of acute of CV complications during hospitalisation for CAP in Internal Medicine Units (IMUs).

Methods

This was a prospective study carried out in 26 IMUs, enrolling patients consecutively hospitalised for CAP. Defined CV complications were: newly diagnosed heart failure, acute coronary syndrome, new onset of supraventricular or ventricular arrhythmias, new onset hemorrhagic or ischemic stroke or transient ischemic attack. Outcome measures were: in-hospital and 30-day mortality, length of hospital stay and rate of 30-day re-hospitalisation.

Results

A total of 1266 patients were enrolled, of these 23.8% experienced at least a CV event, the majority (15.5%) represented by newly diagnosed decompensated heart failure, and 75% occurring within 3 days. Female gender, a history of CV disease, and more severe pneumonia were predictors of CV events. In-hospital (12.2% vs 4.7%, p < 0.0001) and 30-day (16.3% vs 8.9%, p = 0.0001) mortality was higher in patients with CV events, as well as the re-hospitalisation rate (13.3% vs 9.3%, p = 0.002), and mean hospital stay was 11.4 ± 6.9 vs 9.5 ± 5.6 days (p < 0.0001). The occurrence of CV events during hospitalisation significantly increased the risk of 30-day mortality (HR 1.69, 95% CI 1.14–2.51; p = 0.009).

Conclusion

Cardiovascular events are frequent in CAP, and their occurrence adversely affects outcome. A strict monitoring might be useful to intercept in-hospital CV complications for those patients with higher risk profile.

Trial registration

NCT03798457

Registered 10 January 2019 - Retrospectively registered

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-05781-w.

Short-term exposure to air pollution and hospital admission for pneumonia: a systematic review and meta-analysis

BACKGROUND

Air pollution is a major issue that poses a health threat worldwide. Although several studies investigated the adverse effects of air pollution on various diseases, few have directly demonstrated the effects on pneumonia. Therefore, we performed a systematic review and meta-analysis on the associations between short-term exposure of air pollutants and hospital admission or emergency room (ER) visit for pneumonia.

METHODS

A literature search was performed using PubMed, Embase, and Web of Science up to April 10, 2020. Pooled estimates were calculated as % increase with 95% confidence intervals using a random-effects model. A sensitivity analysis using the leave-one-out method and subgroup analysis by region were performed.

RESULTS

A total of 21 studies were included in the analysis. Every 10 μg/m3 increment in PM2.5 and PM10 resulted in a 1.0% (95% CI: 0.5-1.5) and 0.4% (95% CI: 0.2-0.6) increase in hospital admission or ER visit for pneumonia, respectively. Every 1 ppm increase of CO and 10 ppb increase of NO2, SO2, and O3 was associated with 4.2% (95% CI: 0.6-7.9), 3.2% (95% CI: 1.3-5.1), 2.4% (95% CI: - 2.0-7.1), and 0.4% (95% CI: 0-0.8) increase in pneumonia-specific hospital admission or ER visit, respectively. Except for CO, the sensitivity analyses yielded similar results, demonstrating the robustness of the results. In a subgroup analysis by region, PM2.5 increased hospital admission or ER visit for pneumonia in East Asia but not in North America.

CONCLUSION

By combining the inconsistent findings of several studies, this study revealed the associations between short-term exposure of air pollutants and pneumonia-specific hospital admission or ER visit, especially for PM and NO2. Based on the results, stricter intervention policies regarding air pollution and programs for protecting human respiratory health should be implemented.

Successful treatment of 28 patients with coronavirus disease 2019 at a medical center in Taiwan

BACKGROUND

Coronavirus disease-2019 (COVID-19) is a worldwide pandemic. We present the clinical characteristics and outcomes of 28 COVID-19 patients treated in our hospital in Taiwan.

METHODS

Patients with COVID-19, confirmed by positive real-time reverse-transcriptase polymerase chain reaction results for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral nucleic acids from oropharyngeal swab specimens between February 4, 2020 and July 6, 2020, were enrolled. Their clinical characteristics and outcomes were reviewed.

RESULTS

Seventeen of the 28 patients (60.7%) had pneumonia. The most frequent symptoms were cough (n = 23, 82.1%) and fever (n = 17, 60.7%). The development of pneumonia was associated with age ≥40 years (p < 0.024), body mass index (BMI) ≥25 kg/m2 (p = 0.014), fever (p = 0.007), shortness of breath (p = 0.036), chills ((p = 0.047), and lower platelet counts (<200,000/μL) (p = 0.007). Increased quarantine duration was associated with age ≥40 years (p = 0.026), Charlson index ≥1 (p = 0.037), lower lymphocyte (<1500/uL; p = 0.028) or platelet counts (<200,000/μL) (p = 0.016), lower serum sodium (<140 mEq/L; p = 0.006), and higher C-reactive protein (CRP) level (≥1 mg/dl; p = 0.04). Treatment with hydroxychloroquine or in combination with other medicines did not reduce the quarantine duration. All 28 patients recovered with a median quarantine duration of 27.2 days.

CONCLUSION

COVID-19 patients with older age, higher BMI, fever, chills or shortness of breath, lower serum sodium level, lower platelet or lymphocyte count, and higher CRP level may be associated with developing pneumonia or longer quarantine duration.

Efficacy of Respiratory Physiotherapy Interventions for Intubated and Mechanically Ventilated Adults with Pneumonia: A Systematic Review and Meta-Analysis

Purpose: A systematic review was conducted to investigate the effect of respiratory physiotherapy on mortality, quality of life, functional recovery, intensive care length of stay, duration of ventilation, oxygenation, secretion clearance, and pulmonary mechanics for invasively ventilated adults with pneumonia. Method: Five databases were searched for randomized trials published between January 1995 and November 2018. Study quality was assessed using a standardized Joanna Briggs Institute critical appraisal tool, and Review Manager software was used to pool the studies. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to evaluate the level of certainty of the evidence. Results: A total of 14 studies of moderate quality included 251 subjects with pneumonia. Eight studies were pooled for meta-analysis. Interventions that increased inspiratory volume appeared to benefit secretion clearance by nearly 2 grams (mean difference [MD] 1.97; 95% CI: 0.80, 3.14; very low GRADE evidence) and increase static lung compliance immediately after treatment by more than 5 millilitres/centimetre H20 (MD 5.40 mL/cm H2O; 95% CI: 2.37, 8.43; very low GRADE evidence) or by more than 6 millilitres/centimetre H2O after a 20- to 30-minute delay (MD 6.86 mL/cm H2O; 95% CI: 2.86, 10.86; very low GRADE evidence). No adverse events were found. Conclusions: Respiratory physiotherapy that increases tidal volume may benefit secretion clearance and lung compliance in invasively ventilated adults with pneumonia, but its impact on other outcomes, including mortality, length of stay, and other patient-centred outcomes, is unclear, and further research is required.

The Microbiota-Gut-Brain Axis and Alzheimer's Disease: Neuroinflammation Is to Blame?

For years, it has been reported that Alzheimer’s disease (AD) is the most common cause of dementia. Various external and internal factors may contribute to the early onset of AD. This review highlights a contribution of the disturbances in the microbiota–gut–brain (MGB) axis to the development of AD. Alteration in the gut microbiota composition is determined by increase in the permeability of the gut barrier and immune cell activation, leading to impairment in the blood–brain barrier function that promotes neuroinflammation, neuronal loss, neural injury, and ultimately AD. Numerous studies have shown that the gut microbiota plays a crucial role in brain function and changes in the behavior of individuals and the formation of bacterial amyloids. Lipopolysaccharides and bacterial amyloids synthesized by the gut microbiota can trigger the immune cells residing in the brain and can activate the immune response leading to neuroinflammation. Growing experimental and clinical data indicate the prominent role of gut dysbiosis and microbiota–host interactions in AD. Modulation of the gut microbiota with antibiotics or probiotic supplementation may create new preventive and therapeutic options in AD. Accumulating evidences affirm that research on MGB involvement in AD is necessary for new treatment targets and therapies for AD.

Usefulness of circulating microRNAs miR-146a and miR-16-5p as prognostic biomarkers in community-acquired pneumonia

Introduction

Patients with community-acquired pneumonia (CAP) undergo a dysregulated host response that is related to mortality. MicroRNAs (miRNAs) participate in this response, but their expression pattern and their role as biomarkers in CAP have not been fully characterized.

Methods

A prospective observational study was performed in a cohort of 153 consecutive patients admitted to hospital with CAP. Clinical and analytical variables were collected, and the main outcome variable was 30-day mortality. Small RNA was purified from plasma of these patients obtained on the first day of admission, and miRNA expression was analyzed by RT-PCR. Univariate and multivariate analyses were carried out through the construction of a logistic regression model. The proposed model was compared with established prognostic clinical scales using ROC curve analysis.

Results

The mean age of the patients included was 74.7 years [SD 15.9]. Their mean PSI was 100.9 [SD 34.6] and the mean modified Charlson index was 2.9 [SD 3.0]. Both miR-146a and miR-16-5p showed statistically significant association with 30-day mortality after admission due to CAP (1.10 vs. 0.23 and 51.74 vs. 35.23, respectively), and this association remained for miR-16-5p in the multivariate analysis adjusted for age, gender and history of bronchoaspiration (OR 0.95, p = 0.021). The area-under-the-curve (AUC) of our adjusted multivariate model (AUC = 0.954 95%CI [0.91–0.99]), was better than those of prognostic scales such as PSI (AUC = 0.799 [0.69–0.91]) and CURB-65 (AUC = 0.722 [0.58–0.86]).

Conclusions

High levels of miR-146a-5p and miR-16-5p upon admission due to CAP are associated with lower mortality at 30 days of follow-up. Both miRNAs could be used as biomarkers of good prognosis in subjects hospitalized with CAP.

Impact of comprehensive molecular testing to reduce antibiotic use in community-acquired pneumonia (RADICAP): a randomised, controlled, phase IV clinical trial protocol

INTRODUCTION

Community-acquired pneumonia (CAP) continues to be a major health problem worldwide and is one of the main reasons for prescribing antibiotics. However, the causative agent is often not identified, resulting in antibiotic overtreatment, which is a key driver of antimicrobial resistance and adverse events. We aim to test the hypothesis that comprehensive molecular testing, compared with routine microbiological testing, would be effective in reducing antibiotic use in patients with CAP.

METHODS AND ANALYSIS

We will perform a randomised, controlled, open-label clinical trial with two parallel groups (1:1) at two tertiary hospitals between 2020 and 2022. Non-severely immunosuppressed adults hospitalised for CAP will be considered eligible. Patients will be randomly assigned to receive either the experimental diagnosis (comprehensive molecular testing plus routine microbiological testing) or standard diagnosis (only microbiological routine testing). The primary endpoint will be antibiotic consumption measured as days of antibiotic therapy per 1000 patient-days. Secondary endpoints will be de-escalation to narrower antibiotic treatment, time to switch from intravenous to oral antibiotics, days to reaching an aetiological diagnosis, antibiotic-related side effects, length of stay, days to clinical stability, intensive care unit admission, days of mechanical ventilation, hospital readmission up to 30 days after randomisation and death from any cause by 48 hours and 30 days after randomisation. We will need to include 440 subjects to be able to reject the null hypothesis that both groups have equal days of antibiotic therapy per 1000 patient-days with a probability >0.8.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from the Ethics Committee of Bellvitge Hospital (AC028/19) and from the Spanish Medicines and Medical Devices Agency, and it is valid for all participating centres under existing Spanish legislation. Results will be presented at international meetings and will be made available to patients, their caregivers and funders.

TRIAL REGISTRATION NUMBER

ClinicalTrials: NCT04158492. EudraCT: 2018-004880-29.

Lefamulin vs moxifloxacin for community-acquired bacterial pneumonia

Lefamulin is a novel pleuromutilin antibiotic with potent in vitro activity against key community-acquired bacterial pneumonia (CABP) pathogens. However, the clinical efficacy and safety of lefamulin for treating CABP remains unclear.An integrated analysis of 2 phase III trials investigating the clinical efficacy and safety of lefamulin vs moxifloxacin in the treatment of CABP was conducted.A total of 1289 patients (lefamulin group: 646 and moxifloxacin group: 643) were included in this analysis. The early clinical response rate was 89.3% and 90.5% among lefamulin and moxifloxacin group, respectively. Lefamulin was noninferior to moxifloxacin (89.3% vs 90.5%, RR: 0.99, 95% CI: 0.95-1.02, I = 0%). In terms of clinical response at test of cure, no significant difference was observed between the lefamulin and moxifloxacin groups (for modified intention to treat population, RR: 0.98, 95% CI: 0.94-1.02, I = 0%; for clinically evaluable population, RR: 0.96, 95% CI: 0.93-1.00, I = 0%). In the subgroup analysis, the early clinical response rate at early clinical assessment and clinical response rate at test of cure of lefamulin was similar to that of moxifloxacin across different subgpopulations and all baseline CABP pathogens. Lefamulin was associated with a similar risk of adverse events as moxifloxacin.Clinical efficacy and tolerability for lefamulin in the treatment of CABP were similar to those for moxifloxacin.

Correlation Between Serum Levels of 25-Hydroxyvitamin D and Severity of Community-Acquired Pneumonia in Hospitalized Patients Assessed by Pneumonia Severity Index: An Observational Descriptive Study

Introduction Pneumonia severity index (PSI) is a prognostic index used for estimating the possibility of death due to community-acquired pneumonia. Vitamin D is a fat-soluble vitamin, essential for calcium and phosphate homeostasis. Vitamin D also has antimicrobial properties and according to recent studies, its deficiency may be correlated to an increased frequency of respiratory infections. The serum concentration of 25-hydroxyvitamin D (25(OH)D) is the best vitamin D status index reflecting vitamin D produced in the skin and offered from food and dietary supplements. Methods The study involved patients, who fulfilled the criteria of community-acquired pneumonia. The exclusion criteria were: patients <18 years old, severely immunocompromised patients, patients with tuberculosis, patients with malabsorption disorders, nursing home residents, patients with a history of malignancy, chronic renal or liver disease, patients with congestive health failure or cerebrovascular disease, and patients receiving vitamin D as a supplement. The following parameters, recorded on admission, were evaluated: age, sex, co-morbidity, residence in a nursing home, duration of symptoms, clinical symptoms, confusion, blood gas analysis, chest radiograph (pleural effusion), and laboratory parameters. The patients were classified in risk classes according to the PSI. Blood samples were collected within the first 48 hours of hospitalization. The serum levels of 25-hydroxyvitamin D were determined by electrochemiluminescence binding assay in Roche Cobas 601 immunoassay analyzer and mean serum levels of 25-hydroxyvitamin D in each risk class were calculated. For statistical analysis, the statistical program SPSS for Windows version 17.0 (Statistical Package for the Social Sciences, SPSS Inc., Chicago, IL) was used. Results A total of 46 patients, 28 males and 18 females, with a mean age of 71.5±17.57 years, hospitalized with community-acquired pneumonia, were included. Sixteen patients (35%) had a severe deficiency, with 25(OH)D levels <10 ng/ml, 17 patients (37%) had moderate deficiency with 25(OH)D levels between 10-20 ng/ml, and 13 patients (28%) had insufficiency with 25(OH)D levels between 20-29 ng/ml. According to the PSI, four (8.7%) patients with a mean age of 53.75±15.43 years were classified as risk class I, 10 (21.7%) patients with a mean age of 54.7±14.82 years as class II, 10 (21.7%) patients with a mean age of 68.41±3.96 years as class III, 17 (37%) patients with a mean age of 84.82±9.73 years as class IV, and five (10.9%) patients with a mean age of 80.2±9.41 years as class V. The mean levels of 25(OH)D were 19.11±11.24 ng/ml in class I, 16.81±8.94 ng/ml in class II, 16.65±9.18 ng/ml in class III, 14.76±10.22 ng/ml in class IV, and 7.49±4.41 ng/ml in class V. There was a positive correlation between low levels of 25(OH)D and the pneumonia severity and statistically significant difference between the mean levels of 25(OH)D in class V (7.49±4.41 ng/ml) compared to overall mean levels in classes I, II, III and IV (16.15±9.49 ng/ml), with p<0.05. Conclusions According to our results, there was a positive association between low levels of 25-hydroxyvitamin D and community-acquired pneumonia severity assessed by PSI. The determination of 25-hydroxyvitamin-D status, mostly in patients >60 years old, may prevent severe community-acquired pneumonia.

Association of Azithromycin Use With Cardiovascular Mortality

IMPORTANCE

Azithromycin is one of the most commonly prescribed antibiotics in the US. It has been associated with an increased risk of cardiovascular death in some observational studies.

OBJECTIVE

To estimate the relative and absolute risks of cardiovascular and sudden cardiac death after an outpatient azithromycin prescription compared with amoxicillin, an antibiotic not known to increase cardiovascular events.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study included 2 large, diverse, community-based integrated care delivery systems with comprehensive capture of encounters and prescriptions from January 1, 1998, to December 31, 2014. The cohort included patients aged 30 to 74 years who had at least 12 months of health-plan enrollment prior to antibiotic exposure. The exclusion criteria were absence of prescription benefits, prescription for more than 1 type of study antibiotic within 10 days, hospitalization or nursing home residence, and serious medical conditions. Risk of cardiovascular death associated with azithromycin vs amoxicillin exposure was calculated after controlling for confounding factors using a propensity score. Data were analyzed from December 1, 2016, to March 30, 2020.

EXPOSURES

Outpatient prescription of azithromycin or amoxicillin.

MAIN OUTCOMES AND MEASURES

The primary outcomes were cardiovascular death and sudden cardiac death. An a priori subgroup analysis quantified the effects of azithromycin exposure among patients with increased baseline cardiovascular risk. The secondary outcomes were noncardiovascular death and all-cause mortality.

RESULTS

The study included 7 824 681 antibiotic exposures, including 1 736 976 azithromycin exposures (22.2%) and 6 087 705 amoxicillin exposures (77.8%), among 2 929 008 unique individuals (mean [SD] age, 50.7 [12.3] years; 1 810 127 [61.8%] women). Azithromycin was associated with a significantly increased hazard of cardiovascular death (hazard ratio [HR], 1.82; 95% CI, 1.23-2.67) but not sudden cardiac death (HR, 1.59; 95% CI, 0.90-2.81) within 5 days of exposure. No increases in risk were found 6 to 10 days after exposure. Similar results were observed in patients within the top decile of cardiovascular risk (HR, 1.71; 95% CI, 1.06-2.76). Azithromycin was also associated with an increased risk of noncardiovascular death (HR, 2.17; 95% CI, 1.44-3.26) and all-cause mortality (HR, 2.00; 95% CI, 1.51-2.63) within 5 days of exposure.

CONCLUSIONS AND RELEVANCE

These findings suggest that outpatient azithromycin use was associated with an increased risk of cardiovascular death and noncardiovascular death. Causality cannot be established, particularly for noncardiovascular death, owing to the likelihood of residual confounding.

New antibiotics for community-acquired pneumonia

PURPOSE OF REVIEW

This review provides the rationale for the development of new antibiotics to treat community-acquired pneumonia (CAP). It also provides an overview of the new antibiotics targeting CAP that have recently received approval by the regulatory agencies, and those antibiotics that are in the development pipeline.

RECENT FINDINGS

CAP is one of the most common reasons for hospitalization and carries a significant morbidity and risk of mortality. Increasing antibiotic resistance amongst the common bacterial pathogens associated with CAP, especially staphylococci and Streptococcus pneumoniae, has made the empiric treatment of this infection increasingly problematic. Moreover, failure of initial empiric therapy to cover the causative agents associated with CAP can be associated with worse clinical outcomes. There have been several antibiotics newly approved or in development for the treatment of CAP. These agents include delafloxacin, omadacycline, lefamulin, solithromycin, nemonoxacin, and ceftaroline. Their major advantages include activity against methicillin-resistant Staphylococcus aureus and macrolide-resistant Strep. pneumoniae.

SUMMARY

CAP continues to be an important infection because of its impact on patient outcomes especially in the elderly and immunocompromised hosts. The availability of new antibiotics offers an opportunity for enhanced empiric treatment of the antibiotic-resistant bacterial pathogens associated with CAP.

Diagnostic value of pentraxin 3 in respiratory tract infections: A meta-analysis

BACKGROUND

Pentraxin 3 is an acute inflammatory protein of the long pentraxin subfamily. A meta-analysis was performed to assess diagnostic accuracy of pentraxin 3 for respiratory tract infections.

METHODS

We identify studies examining diagnostic value of pentraxin 3 for respiratory tract infections by searching Pubmed, Web of Knowledge, and Cochrane Library. The sensitivity, specificity, negative likelihood ratio (LR), positive LR, and diagnostic odds ratio were pooled. The area under the summary receiver operator characteristic (SROC) curve and Q point value (Q*) were calculated.

RESULTS

A total of 8 studies with 961 individuals were eligible for this meta-analysis. The pooled sensitivity of pentraxin 3 in diagnosis of respiratory tract infections was 0.78, the pooled specificity was 0.73, the area under the SROC curve was 0.84, and the Q* was 0.77. The area under the SROC curve of serum and bronchoalveolar lavage fluid (BALF) pentraxin 3 was 0.85 and 0.89, respectively. Meta-regression analysis revealed that cutoff value was the source of heterogeneity among the included studies. The Deek funnel plot test suggested no evidence of publication bias. Subgroup analyses showed that the area under the SROC curve of pentraxin 3 in diagnosis of ventilator-associated pneumonia (VAP) was 0.89.

CONCLUSION

Pentraxin 3 has a moderate accuracy for diagnosing respiratory tract infections and VAP. The overall diagnostic value of BALF level of pentraxin 3 is superior to its serum concentration.

Lymphocyte-To-Monocyte Ratio as the Best Simple Predictor of Bacterial Infection in Patients with Liver Cirrhosis

Background and aim: The aim of this study was to assess the diagnostic performance of new morphology-related indices and Child–Turcotte–Pugh (CTP) and Model for End-Stage Liver Disease (MELD) scores during hospitalization in predicting the onset of bacterial infection in patients with liver cirrhosis. Material and methods: A total of 171 patients (56.9% males; median age 59 years; total number of hospitalizations 209) with liver cirrhosis were included in this observational study. The diagnosis of cirrhosis was made on the basis of clinical, biochemical, ultrasonic, histological, and endoscopic findings. The neutrophil-to-lymphocyte ratio (NLR), lymphocyte-to-monocyte ratio (LMR), modified aspartate aminotransferase-to-platelet ratio index (APRI), aspartate aminotransferase-to-alanine aminotransferase ratio (AAR), Fibrosis-4 index (FIB-4), platelet-to-lymphocyte ratio (PLR), neutrophil-to-monocyte ratio (NMR), and CTP and MELD scores were calculated for the cases of patients with cirrhosis. Results: Bacterial infection was diagnosed in 60 of the 209 (28.7%) hospitalizations of patients with cirrhosis. The most common infections were urinary tract infection (UTI), followed by pneumonia and sepsis. The more severe the liver failure, the greater the bacterial infection prevalence and mortality. Patients with decompensated liver cirrhosis were infected more often than subjects with compensated cirrhosis (50.0% vs. 12.9%, p = 0.003). The calculated MELD score, CTP, NLR, LMR, AAR, monocyte count, and C-reactive protein (CRP) concentration were also related to the bacterial infection prevalence, and mortality areas under the curve (AUC) were 0.629, 0.687, 0.606, 0.715, 0.610, 0.648, and 0.685, respectively. The combined model with two variables (LMR and CTP) had the best AUC of 0.757. The most common bacteria isolated from patients with UTI were Escherichia coli, Enterococcus faecalis, and Klebsiella pneumonia. Gram-negative bacteria were also responsible for spontaneous bacterial peritonitis (SBP), and together with gram-positive streptococci and staphylococci, these microorganisms were isolated from blood cultures of patients with sepsis. Significant differences were found between CTP classification, MELD score, NLR, LMR, AAR, CRP, and PLR in patients with cirrhosis with, or without, bacterial infection. Conclusions: Bacterial infection prevalence is relatively high in patients with liver cirrhosis. Although all analyzed scores, including the LMR, NLR, aspartate aminotransferase (AST)/alanine aminotransferase (ALT), CRP, CTP, and MELD, allowed the prediction of bacterial occurrence, the LMR had the highest clinical utility, according to the area under the curve (AUC) and odds ratio (OR).

Next-generation sequencing diagnosis of severe pneumonia from fulminant psittacosis with multiple organ failure: a case report and literature review

This study includes a retrospective analysis of the diagnosis and treatment of a case of severe pneumonia from fulminant psittacosis with multiple organ failure. Next-generation sequencing (NGS) of the pathogen was conducted. The purpose of this study was to summarize the clinical, laboratory, and imaging characteristics of the case and to improve understanding of the value of NGS in the diagnosis of severe community-acquired pneumonia (CAP). Fulminant psittacosis can be manifested as severe pneumonia with rapid progression, acute respiratory distress syndrome, sepsis, and multiple organ failure. Imaging shows unilateral lung consolidation, which is difficult to differentiate from CAP caused by common pathogens. The NGS technology can early detect rare pathogens, thus reducing unnecessary use of antibiotics and shortening the course of the disease.

Community Acquired Pneumonia

Early identification of patients with severe community-acquired pneumonia (SCAP) who require ICU care is important as delayed transfer is associated with increased mortality. In such patients, aggressive diagnostic testing is warranted given the increased probability of detecting a pathogen resistant to usual empirical therapy. Despite aggressive culture and other routine diagnostic testing, the majority of cases of SCAP remain without a definitive etiology. Early coverage of S. pneumoniae, methicillin-susceptible S. aureus, and L. pneumophila is crucial and adequate in the absence of risk factors for drug-resistant pathogens. Combination antibiotics with a beta-lactam and either a macrolide or fluoroquinolone are strongly recommended. When methicillin-resistant Staphylococcus aureus is suspected, linezolid is superior to vancomycin.

Several aspects of managing severe CAP remain without consensus, including risk factors for multidrug resistant pathogens, need for suppression of exotoxin production, the role of procalcitonin, and adjunctive treatment with corticosteroids and extracorporeal membrane oxygenation.

Host-response biomarkers for the diagnosis of bacterial respiratory tract infections

Appropriate antibiotic treatment for respiratory tract infections (RTIs) necessitates rapid and accurate diagnosis of microbial etiology, which remains challenging despite recent innovations. Several host response-based biomarkers due to infection have been suggested to allow discrimination of bacterial and non-bacterial microbial RTI etiology. This review provides an overview of clinical studies that investigated the diagnostic performance of host-response proteomic biomarkers to identify RTI microbial etiology. Procalcitonin and C-reactive protein have been studied most extensively; whereof procalcitonin has demonstrated the strongest diagnostic performance compared to other biomarkers. Proadrenomedullin, soluble triggering receptor expressed on myeloid cells-1, neopterin and pentraxin-3 need more studies to confirm their diagnostic value. For syndecan-4 and lipocalin-2 currently insufficient evidence exists. Common limitations in several of the studies were the relatively small scale setting, heterogeneous patient population and the absence of statistical power calculation.

Steroid therapy and outcome of parapneumonic pleural effusions (STOPPE): Study protocol for a multicenter, double-blinded, placebo-controlled randomized clinical trial

BACKGROUND

Community-acquired pneumonia (CAP) is a major global disease. Parapneumonic effusions often complicate CAP and range from uninfected (simple) to infected (complicated) parapneumonic effusions and empyema (pus). CAP patients who have a pleural effusion at presentation are more likely to require hospitalization, have a longer length of stay and higher mortality than those without an effusion. Conventional management of pleural infection, with antibiotics and chest tube drainage, fails in about 30% of cases. Several randomized controlled trials (RCT) have evaluated the use of corticosteroids in CAP and demonstrated some potential benefits. Importantly, steroid use in pneumonia has an acceptable safety profile with no adverse impact on mortality. A RCT focused on pediatric patients with pneumonia and a parapneumonic effusion demonstrated shorter time to recovery. The effects of corticosteroid use on clinical outcomes in adults with parapneumonic effusions have not been tested. We hypothesize that parapneumonic effusions develop from an exaggerated pleural inflammatory response. Treatment with systemic steroids may dampen the inflammation and lead to improved clinical outcomes. The steroid therapy and outcome of parapneumonic pleural effusions (STOPPE) trial will assess the efficacy and safety of systemic corticosteroid as an adjunct therapy in adult patients with CAP and pleural effusions.

METHODS

STOPPE is a pilot multicenter, double-blinded, placebo-controlled RCT that will randomize 80 patients with parapneumonic effusions (2:1) to intravenous dexamethasone or placebo, administered twice daily for 48 hours. This exploratory study will capture a wide range of clinically relevant endpoints which have been used in clinical trials of pneumonia and/or pleural infection; including, but not limited to: time to clinical stability, inflammatory markers, quality of life, length of hospital stay, proportion of patients requiring escalation of care (thoracostomy or thoracoscopy), and mortality. Safety will be assessed by monitoring for the incidence of adverse events during the study.

DISCUSSION

STOPPE is the first trial to assess the efficacy and safety profile of systemic corticosteroids in adults with CAP and pleural effusions. This will inform future studies on feasibility and appropriate trial endpoints.

TRIAL REGISTRATION

ACTRN12618000947202 PROTOCOL VERSION:: version 3.00/26.07.18.

Animal Models of Pneumococcal pneumonia

Streptococcus pneumoniae remains the most common bacterial pathogen causing lower respiratory tract infections and is a leading cause of morbidity and mortality worldwide, especially in children and the elderly. Another important aspect related to pneumococcal infections is the persistent rate of penicillin and macrolide resistance. Therefore, animal models have been developed to better understand the pathogenesis of pneumococcal disease and test new therapeutic agents and vaccines. This narrative review will focus on the characteristics of the different animal pneumococcal pneumonia models. The assessment of the different animal models will include considerations regarding pneumococcal strains, microbiology properties, procedures used for bacterial inoculation, pathogenesis, clinical characteristics, diagnosis, treatment, and preventive approaches.