Community-acquired pneumonia: An overview

Improvement of pneumococcal pneumonia diagnosis using quantitative real-time PCR targeting lytA in adult patients: a prospective cohort study

OBJECTIVES

The aim of the study was to assess the performance of real-time PCR targeting the lytA gene (rtPCR-lytA) in plasma, urine and nasopharyngeal (NP) samples for the diagnosis of pneumococcal community-acquired pneumonia (P-CAP).

METHODS

Prospective observational study including all consecutive adults with CAP from November 2015 to May 2017. P-CAP was defined if pneumococcus was identified using conventional methods (CM) and/or a positive rtPCR-lytA was detected in blood, urine or NP samples (NP cut-off ≥8000 copies/mL). Diagnostic performance of each test was calculated.

RESULTS

A total of 133 individuals with CAP were included. Of these, P-CAP was diagnosed in 62 (46.6%). The proportion of P-CAP diagnosed by rtPCR-lytA methods was significantly higher than that diagnosed by CM (87.1% versus 59.7%, p 0.005). The rtPCR-lytA identified Streptococcus pneumoniae in 25 patients (40.3% of all individuals with P-CAP) whose diagnosis would have been missed by CM. NP-rtPCR-lytA allowed diagnosis of 62.3% of P-CAP. A nasopharyngeal colonization density ≥2351 copies/mL predicted P-CAP diagnosis (area under the curve = 0.82, sensitivity 83.3%, specificity 80.9%). There was a positive correlation between increasing bacterial load in blood and CURB-65 score (Spearman correlation coefficient r = 0.4, p 0.001), pneumonia severity index (r = 0.3, p 0.02) and time to clinical stability (r = 0.33, p 0.01). Median bacterial load in blood was higher in P-CAP patients with bacteraemia (0.65 × 10³ versus 0 × 10³ copies/mL, p 0.002), intensive care unit admission (0.68 × 10³ versus 0 × 10³ copies/mL, p 0.04) or mechanical ventilation (7.45 × 10³ versus 0 × 10³ copies/mL, p 0.04).

CONCLUSIONS

The use of rtPCR-lytA methods significantly increased the diagnosis of P-CAP compared with CM. Nasopharyngeal swabs rtPCR-lytA detection, with an accurate cut-off value, was the most promising among molecular methods for the diagnosis of P-CAP.

LncRNA NEAT1 Regulates Infantile Pneumonia by Sponging miR-146b

This study designed to investigate the potential role of lncRNA NEAT1/miR-146b in infantile pneumonia. In this study, 58 children with pneumonia and 58 healthy children collected for routine examination from December 2016 to January 2019. The lncRNA NEAT1 and miR-146b expression levels were detected by qPCR in both groups. The pneumonia model was established by inducing human embryonic lung fibroblasts HFL1 with LPS, and then transfected with lncRNA NEAT1 inhibition and miR-146b over-expression vector to observe the effect on cell viability and apoptosis after induction. Starbase predicted the binding site between lncRNA NEAT1 and miR-146b, and the targeted relationship between them was detected by dual luciferase reporter gene. The relative expression of lncRNA NEAT1 in serum of infantile pneumonia was up-regulated. Knocking down lncRNA NEAT1 promotes cell growth and reduces apoptosis in LPS-induced HFL1 cells. Results showed that the fluorescence activity of lncRNA NEAT1 obviously reduced when combined with miR-146b. In conclusion, the relative expression of miR-146b in serum of infantile pneumonia decreased, and over-expressing it could promote LPS-induced cell viability and reduce apoptosis. Taken together, this study demonstrated that the lncRNA NEAT1 regulates infantile pneumonia by sponging miR-146b.

Upregulated-gene expression of pro-inflammatory cytokines, oxidative stress and apoptotic markers through inflammatory, oxidative and apoptosis mediated signaling pathways in Bovine Pneumonia

Pneumonia is the acute inflammation of lung tissue and is multi-factorial in etiology. Staphylococcus aureus (S. aureus) is a harmful pathogen present as a normal flora of skin and nares of dairy cattle. In bovine pneumonia, S. aureus triggers to activates Toll-Like Receptors (TLRs), that further elicits the activation of the inflammation via NF-κB pathway, oxidative stress and apoptotic pathways. In the current study, pathogen-associated gene expression of the pro-inflammatory cytokines, oxidative stress and apoptotic markers in the lung tissue of cattle was explored in bovine pneumonia. Fifty lung samples collected from abattoir located in Wuhan city, Hubei, China. Histopathologically, thickening of alveolar wall, accumulation of inflammatory cells and neutrophils in perivascular space, hyperemia, hemorrhages and edema were observed in infected lungs as compared to non-infected lung samples. Furthermore, molecular identification and characterization were carried by amplification of S. aureus-specific nuc gene (270 base pairs) from the infected and non-infected lung samples to identify the S. aureus. Moreover, qPCR results displayed that relative mRNA levels of TLR2, TLR4, pro-inflammatory gene (IL-1β, IL-6 and TNF-α) and apoptosis-associated genes (Bax, caspase-3 and caspase-9) were up-regulated except Bcl-2, which is antiapoptotic in nature, and oxidative stress related genes (Nrf2, NQO1, HO-1 and GCLC) which was down-regulated in infected pulmonary group. The relative protein expression of NF-κB, mitochondria-mediated apoptosis gene was up-regulated while Bcl-2 and Nrf2 pathway genes were downregulated in infected cattle lungs. Our findings revealed that genes expression levels of inflammatory mediators, oxidative stress and apoptosis were associated with host immunogenic regulatory mechanisms in the lung tissue during infection. Conclusively, the present study provides insights of active immune response via TLRs-mediated inflammatory, oxidative damage, and apoptotic paradox.

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.

The clinical path to deliver encapsulated phages and lysins

The global emergence of multidrug-resistant pathogens is shaping the current dogma regarding the use of antibiotherapy. Many bacteria have evolved to become resistant to conventional antibiotherapy, representing a health and economic burden for those afflicted. The search for alternative and complementary therapeutic approaches has intensified and revived phage therapy. In recent decades, the exogenous use of lysins, encoded in phage genomes, has shown encouraging effectiveness. These two antimicrobial agents reduce bacterial populations; however, many barriers challenge their prompt delivery at the infection site. Encapsulation in delivery vehicles provides targeted therapy with a controlled compound delivery, surpassing chemical, physical and immunological barriers that can inactivate and eliminate them. This review explores phages and lysins' current use to resolve bacterial infections in the respiratory, digestive, and integumentary systems. We also highlight the different challenges they face in each of the three systems and discuss the advances towards a more expansive use of delivery vehicles.

T-B cell epitope peptides induce protective immunity against Mycoplasma pneumoniae respiratory tract infection in BALB/c mice

Mycoplasma pneumoniae is the most common pathogen of community-acquired pneumonia in humans. Due to its high rates of antibiotic resistance, vaccination has become the best method to control the dissemination of M. pneumoniae. The recombinant carboxyl terminus of the P1 (P1C) protein is an immunodominant antigen, but it has negative effects such as poor stability and lower purity. In the current study, T-B epitopes of the P1C protein were predicted according to bioinformatics analysis and assessed for efficacy in peptide vaccination. BALB/c mice were subcutaneously inoculated with the T-B epitope peptides four times and then infected with M. pneumoniae through the respiratory tract. The results showed that the T-B epitope peptides of the P1C protein (P1C_103-117, P1C_155-169, P1C_224-238 and P1C_244-258) induced strong antigen-specific serum antibody responses and cellular immune responses with high levels of serum IgG, IgA antibodies and Th1-biased (IFN-γ and IL-2) cytokines. Immunization with T-B epitope peptides significantly reduced the M. pneumoniae burden and the degree of inflammation in the challenged mice. Furthermore, the levels of IFN-γ and TNF-α in the supernatants of lung homogenates were observably reduced compared to those in the PBS group. Overall, our findings demonstrate that T-B epitopes (P1C_103-117, P1C_155-169, P1C_224-238 and P1C_244-258) play significant roles in the P1C protein and can be used to induce powerful humoral and cellular immune responses to provide significant protection against M. pneumoniae pulmonary infection, which provides new insight into the design of potential multiepitope vaccines to prevent host infection by M. pneumoniae.

[The use of a new semi-quantitative rapid test for procalcitonin in the diagnosis of multisegmental community-acquired pneumonia]

AIM

Evaluation of the possibilities of a new semi-quantitative rapid test for procalcitonin in the diagnosis of multisegmental community-acquired pneumonia.

MATERIALS AND METHODS

A one-stage comparative study involved 123 patients hospitalized in a hospital with a confirmed diagnosis of community-acquired pneumonia. The mean age of the patients was 49.521.0 (MSD) years. On the first day of hospitalization, all patients underwent a general clinical examination, chest x-ray, and a plasma procalcitonin level was determined using a semi-quantitative rapid test.

RESULTS

Indicators of a new semi-quantitative rapid test for procalcitonin of at least 2 ng/ml are directly related to laboratory and instrumental indicators reflecting the severity of community-acquired pneumonia, namely, the severity of respiratory failure (p=0.001), respiratory rate (p=0.001), and heart rate contractions (p=0.001), systolic blood pressure (p=0.025), oxygen saturation (p=0,001), erythrocyte sedimentation rate (p=0.021), fibrinogen (p=0.003) and high CRB-65 scores (p=0.001). They are also associated with multisegmental community-acquired pneumonia (2=4.7; p=0.030) and complications of this disease, such as hydrothorax (p=0.029) and death (2=22.1; p=0.001).

CONCLUSION

Using a new semi-quantitative rapid test for procalcitonin allows you to optimize the diagnosis of complications of community-acquired pneumonia and determine the high risk of multisegmental pneumonia.

The impact of 10-valent pneumococcal conjugate vaccine upon hospitalization rate of children with pneumonia in different Brazilian administrative regions

BACKGROUND

Streptococcus pneumoniae is the most frequent bacterial causative agent of pneumonia. Due to its significant contribution to the morbidity and mortality profile and the country's economy, the 10-valent pneumococcal vaccine (PCV10) was introduced in Brazil in 2010. Brazil is divided into five administrative regions which differ in social-economic indices among each other. Estimates of PCV10 impact on hospitalization rates due to pneumonia stratified by distinct Brazilian regions are limited. We assessed this issue.

METHODS

This is a population-based ecological investigation. Data about hospitalizations due to pneumonia, asthma or urinary tract infection (UTI) among patients aged under 20 years in the pre-exposure (2003-2009) and in the post-exposure (2011-2017) periods were retrieved from the National Health System - Hospital Information System (SIH-SUS) database. The total resident population by age group in each year was retrieved from the Brazilian Institute for Geography and Statistics database. Hospitalization rates were estimated for each Brazilian region and the rates obtained in the pre-exposure and in the post-exposure periods were compared by Prais-Winsten regression. The Human Development Index (HDI) evolved differently in the distinct regions during the study period.

RESULTS

Overall, hospitalization rates due to pneumonia declined by 34.5%. Similar trends were observed for hospitalization rates due to asthma and UTI. The same pattern was observed in each Brazilian region. However, the North region was the only one that presented an exponential incidence decline pattern, which could be explained by PCV10 implementation (declined by 10.8% in the quadratic regression, p < 0.01). Only in the North region, significant decline was observed among patients aged 0-4 years (-12.5%; p = 0.01), 5-9 years (-38.5%; p < 0.01) or 10-14 years (-10.7%; p = 0.03).

CONCLUSION

Significant variation in the downward trend of hospitalization rate was only found in the North region, which evolved from very low HDI in 2003; medium HDI in 2010 to high HDI in 2017.

Nanoparticle-mediated pulmonary drug delivery: state of the art towards efficient treatment of recalcitrant respiratory tract bacterial infections

Recalcitrant respiratory tract infections caused by bacteria have emerged as one of the greatest health challenges worldwide. Aerosolized antimicrobial therapy is becoming increasingly attractive to combat such infections, as it allows targeted delivery of high drug concentrations to the infected organ while limiting systemic exposure. However, successful aerosolized antimicrobial therapy is still challenged by the diverse biological barriers in infected lungs. Nanoparticle-mediated pulmonary drug delivery is gaining increasing attention as a means to overcome the biological barriers and accomplish site-specific drug delivery by controlling release of the loaded drug(s) at the target site. With the aim to summarize emerging efforts in combating respiratory tract infections by using nanoparticle-mediated pulmonary delivery strategies, this review provides a brief introduction to the bacterial infection-related pulmonary diseases and the biological barriers for effective treatment of recalcitrant respiratory tract infections. This is followed by a summary of recent advances in design of inhalable nanoparticle-based drug delivery systems that overcome the biological barriers and increase drug bioavailability. Finally, challenges for the translation from exploratory laboratory research to clinical application are also discussed and potential solutions proposed.

Incidence and related factors of hypoxia associated with elderly femoral neck fractures in the emergency department setting

Aim

Femoral neck fractures in elderly patients needing oxygen therapy are often encountered in the emergency department. This single‐center, retrospective, observational study aimed to examine the frequency, cause, and factors related to hypoxia in elderly patients with femoral neck fractures.

Methods

We analyzed data from 241 patients admitted to Okayama Saiseikai General Hospital (Okayama, Japan) from April 2016 to March 2019. Hypoxia was defined as PaO₂ / FiO₂ ratio under 300. The independent factors for hypoxia were determined by multiple logistic regression analysis.

Results

There were 194 patients who met the study inclusion criteria, 148 in the non‐hypoxia group and 46 in the hypoxia group. The hypoxia group included patients with pneumonia (n = 3), chronic obstructive pulmonary disease (n = 2), pulmonary edema (n = 1), and pulmonary embolization (n = 1). The cause of hypoxia was undetermined in 39 cases. However, occult fat embolism syndrome was suspected in 29 of these 39 cases based on Gurd and Wilson criteria after considering clinical examination results. Barthel indexes were significantly lower in the hypoxia group on discharge. Age (adjusted odds ratio [OR] 1.07; 95% confidence interval [CI], 1.00–1.14; P = 0.038), D‐dimer (adjusted OR 1.02; 95% CI, 1.00–1.03; P = 0.005), and transtricuspid pressure gradient (adjusted OR 1.03; 95% CI, 1.00–1.07; P = 0.015) were independently associated with the hypoxia.

Conclusion

We found that hypoxia, including undetermined hypoxia, was commonly encountered in the emergency department. Hypoxia in elderly patients with femoral neck fractures was associated with age, D‐dimer, and transtricuspid pressure gradient and needs further investigation.

Efficacy and safety of yinqiao powder combined with western medicine in the treatment of pneumonia: A systematic review and meta-analysis

Objective

This review aimed at systematically evaluating the efficacy and safety of Yinqiao powder combined with western medicine in the treatment of pneumonia.

Methods

A systematic search for randomized controlled trials (RCTs) focusing on pneumonia treatment using a combination of Yinqiao powder and western medicine was performed in PubMed, the Cochrane Library, EMBASE, Web of Science, CNKI, Wanfang, Weipu (VIP) and CBM. The retrieval time limit was from the establishment of the database to June 2020. Two researchers independently screened the literature, extracted the data and evaluated the bias risk of the included studies. A meta-analysis was performed using RevMan5.3 software. Quality of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

Result

Fifteen RCTs involving 1705 patients were included in the analysis. The meta-analysis results revealed the total effective rate of the treatment group [RR = 1.21, 95% CI (1.15, 1.27), P < 0.00001], bacterial clearance rate [RR = 1.13, 95% CI (1.05, 1.22), P = 0.001], adverse reactions [RR = 0.54, 95% CI (0.38, 0.76), P = 0.0005]. There were statistically significant differences in the cooling time, T cell number, procalcitonin (PCT) and C-reactive protein (CRP) value decline rate (P < 0.05). There was no statistically significant difference in the decline rate of neutrophils and leukocytes (P > 0.05).

Conclusion

The current evidence indicated that the Yinqiao powder combined with western medicine can improve total efficiency in the treatment of pneumonia patients. The combination therapy performed better when compared to western medicine alone in the cooling time, bacterial clearance rate, T cell count, decline rates of CRP and PCT as well as in the incidences of adverse reactions. However, there was no significant difference in the decline rates of neutrophils and leucocytes between the two groups. The funnel plot, Egger's test and Begg's test indicated publication bias, which may be associated with unpublished negative study results. Due to the limitation of the quality and quantity of the included studies, more high-quality studies should be performed to verify our conclusions.

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This study comprehensively evaluated the efficacy of Yinqiao powder in the treatment of pneumonia.

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This study will provide evidence-based basis for the treatment of pneumonia with traditional Chinese medicine.

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This study can provide reference for the treatment of COVID-19.

Features and associated factors of bacterial skin infections in hospitalized patients with pemphigus: a single-center retrospective study

BACKGROUND

Infections were the primary cause of death (34.3-55.5%) in patients with pemphigus. Skin was usually the origin of infections. The study aimed to explore features and associated factors of bacterial skin infections (BSIs) in inpatients with pemphigus.

METHODS

One hundred and seventy-seven inpatients with pemphigus hospitalizing from November 2014 to April 2019 were continuously recruited through Peking University First Hospital's inpatient records inpatients with pemphigus hospitalizing from November 2014 to April 2019 were continuously recruited through Peking University First Hospital's inpatient records. Then, we retrieved the clinical and laboratory data to explore the characteristics and associated factors of BSIs.

RESULTS

Of patients enrolled, pemphigus vulgaris (PV, n = 142) and pemphigus foliaceus (PF, n = 9) were most common, followed by pemphigus erythematosus (PE, n = 25) and pemphigus vegetans (Pveg, n = 1). Eighty-seven of 177 (49.2%) inpatients developed BSIs, and they had a longer length of stay compared with inpatients without BSIs (median: 18.9 vs. 14.1 days, p = 0.008). Staphylococcus aureus was the most common bacteria (71.3%, 62/87) and highly resistant to penicillin (91.9%, 57/62). Higher levels of anti-Dsg1 autoantibodies (> 124.2 U/mL) (p < 0.001, odds ratio [OR] = 3.564, 95% confidence interval [CI]: 1.784-7.123) and anti-Dsg3 autoantibodies (> 169.5 U/mL) (p = 0.03, OR = 2.074, 95% CI: 1.084-3.969) were underlying risk factors of BSIs when analyzed by binary regression analysis. As for Gram's stain of bacteria, females had a lower rate of Gram-positive infections (p = 0.03). Patients using oral antibiotics (p = 0.05) had a higher rate of Gram-negative infections. Inpatients who were hospitalized in other hospitals within 2 weeks before the current admission had a higher rate of Gram-negative and co-infections (p = 0.03).

CONCLUSIONS

Inpatients with pemphigus had a high incidence of BSIs. Some factors were associated with the susceptibility of BSIs and bacterial species.

Comparison of the Clinical Characteristics and Severity of Influenza and Non-influenza Respiratory Virus-Related Pneumonia in China: A Multicenter, Real-World Study

Purpose

Respiratory viruses are important etiologies of community-acquired pneumonia (CAP). However, the impact of different RVs on the outcomes of CAP is not well elucidated. This study aims to compare the clinical features and severity of influenza (Flu-p) and non-influenza respiratory viruses-related pneumonia (NIRVs-p) onset in the community among immunocompetent adults.

Methods

The data of the patients hospitalized with laboratory-confirmed RVs-p were retrospectively reviewed from five teaching hospitals in China from January 2013 to May 2019. Univariate and multivariate logistic regressions were performed to compare the clinical characteristics and outcomes between Flu-p and NIRVs-p.

Results

A total of 1079 patients with Flu-p and 341 patients with NIRVs-p were included in this study. A multivariate logistic regression model revealed chronic pulmonary disease [odd ratio (OR) 0.341, 95% confidence interval (CI) 0.225–0.515, p < 0.001], solid malignant tumor (OR 0.330, 95% CI 0.163–0.668, p = 0.002), myalgia (OR 1.697, 95% CI 1.236–2.330, p < 0.001), lymphocytes <0.8×10⁹/L (OR 10.811, 95% CI 6.949–16.818, p < 0.001) and blood albumin <35 g/L (OR 0.327, 95% CI 0.242–0.442, p < 0.001) were predictors for Flu-p. After adjusting for confounders, the multivariate logistic regression analysis confirmed that influenza B-related pneumonia (FluB-p) (OR 0.419, 95% CI 0.272–0.646, p < 0.001) and NIRVs-p (OR 0.260, 95% CI 0.158–0.467, p < 0.001) were associated with a decreased risk of 30-day mortality compared with the influenza A-related pneumonia (FluA-p).

Conclusion

Our results showed that patients with FluA-p experience a more severe disease than those with FluB-p and NIRVs-p. Some clinical features are helpful to distinguish between NIRVs-p and Flu-p.

Derivation and validation of a prediction rule for mortality of patients with respiratory virus-related pneumonia (RV-p score)

Background:

Respiratory viruses are important etiologies of community-acquired pneumonia. However, current knowledge on the prognosis of respiratory virus-related pneumonia (RV-p) is limited. Thus, here we aimed to establish a clinical predictive model for mortality of patients with RV-p.

Methods:

A total of 1431 laboratory-confirmed patients with RV-p, including 1169 and 262 patients from respective derivation and validation cohorts from five teaching hospitals in China were assessed between January 2010 and December 2019. A prediction rule was established on the basis of risk factors for 30-day mortality of patients with RV-p from the derivation cohort using a multivariate logistic regression model.

Results:

The 30-day mortality of patients with RV-p was 16.8% (241/1431). The RV-p score was composed of nine predictors (including respective points of mortality risk): (a) age ⩾65 years (1 point); (b) chronic obstructive pulmonary disease (1 point); (c) mental confusion (1 point); (d) blood urea nitrogen (1 point); (e) cardiovascular disease (2 points); (f) smoking history (2 points); (g) arterial pressure of oxygen/fraction of inspiration oxygen (P_aO₂/FiO₂) < 250 mmHg (2 points); (h) lymphocyte counts <0.8 × 10⁹/L (2 points); (i) arterial PH < 7.35 (3 points). A total of six points was used as the cut-off value for mortality risk stratification. Our model showed a sensitivity of 0.831 and a specificity of 0.783. The area under the receiver operating characteristic curve was more prominent for RV-p scoring [0.867, 95% confidence interval (CI)0.846–0.886] when compared with both pneumonia severity index risk (0.595, 95% CI 0.566–0.624, p < 0.001) and CURB-65 scoring (0.739, 95% CI 0.713–0.765, p < 0.001).

Conclusion:

RV-p scoring was able to provide a good predictive accuracy for 30-day mortality, which accounted for a more effective stratification of patients with RV-p into relevant risk categories and, consequently, help physicians to make more rational clinical decisions.

The reviews of this paper are available via the supplemental material section.

Advanced engineering of third-generation lysins and formulation strategies for clinical applications

One of the possible solutions for the current antibiotic resistance crisis may be found in (often bacteriophage-derived) peptidoglycan hydrolases. The first clinical trials of these natural enzymes, coined here as first-generation lysins, are currently ongoing. Moving beyond natural endolysins with protein engineering established the second generation of lysins. In second-generation lysins, the focus lies on improving antibacterial and biochemical properties such as antimicrobial activity and stability, as well as expanding their activities towards Gram-negative pathogens. However, solutions to particular key challenges regarding clinical applications are only beginning to emerge in the third generation of lysins, in which protein and biochemical engineering efforts focus on improving properties relevant under clinical conditions. In addition, increasingly advanced formulation strategies are developed to increase the bioavailability, antibacterial activity, and half-life, and to reduce pro-inflammatory responses. This review focuses on third-generation and advanced formulation strategies that are developed to treat infections, ranging from topical to systemic applications. Together, these efforts may fully unlock the potential of lysin therapy and will propel it as a true antibiotic alternative or supplement.

Development and Implementation of a Clinical Pathway to Reduce Inappropriate Admissions Among Patients with Community-Acquired Pneumonia in a Private Health System in Brazil: An Observational Cohort Study and a Promising Tool for Efficiency Improvement

Purpose

Patients with community-acquired pneumonia (CAP) at low risk of death by CURB-65 scoring system are usually unnecessarily treated as inpatients generating additional economic and clinical burden. We aimed to implement an evidence-based clinical pathway to reduce hospital admissions of low-risk CAP and investigate factors related to mortality and readmissions within 30 days.

Patients and Methods

From November 2015 to August 2017, a clinical pathway was implemented at 20 hospitals. We included patients aged >18 years, with a diagnosis of CAP by the attendant physician. The main outcome was the monthly proportion of low-risk CURB-65 admission after the implementation of the clinical pathway. Logistic regression models were performed to assess variables associated with mortality and readmission in the admitted population within 30 days.

Results

We included 10,909 participants with suspected CAP. The proportion of low-risk CAP admitted decreased from 22.1% to 12.8% in the period. Among participants with low risk, there has been no perceptible increase in deaths (0.80%) or readmissions (6.92%). Regression analysis identified that CURB-65 variables, presence of pleural effusion (OR= 1.74; 95%CI=1.08–2.8; p=0.02) and leucopenia (OR= 2.47; 95%CI=1.11–5.48; p=0.02) were independently associated with 30-day mortality, whereas a prolonged hospital stay (OR= 2.09; 95%CI=1.14–3.83; p=0.01) was associated with 30-day readmission in the low-risk population.

Conclusion

The implementations of a clinical pathway diminished the proportion of low-risk CAP admissions with no apparent increase in clinical outcomes within 30 days. Nonetheless, additional factors influence the clinical decision about the site of care management in low-risk CAP.

Anemoside B4 protects against Klebsiella pneumoniae- and influenza virus FM1-induced pneumonia via the TLR4/Myd88 signaling pathway in mice

Background

Pneumonia refers to the inflammation of the terminal airway, alveoli and pulmonary interstitium, which can be caused by pathogenic microorganisms, physical and chemical factors, immune damage, and drugs. Anemoside B4, the major ingredient of Pulsatilla chinensis (Bunge) Regel, exhibited anti-inflammatory activity. However, the therapeutic effect of anemoside B4 on pneumonia has not been unraveled. This study aims to investigate that anemoside B4 attenuates the inflammatory responses in Klebsiella pneumonia (KP)- and influenza virus FM1 (FM1)-induced pneumonia mice model.

Methods

The network pharmacology and molecular docking assays were employed to predict the targets of anemoside B4’s treatment of pneumonia. Two models (bacterial KP-infected mice and virus FM1-infected mice) were employed in our study. BALB/c mice were divided into six groups: control, model group (KP-induced pneumonia or FM1-induced pneumonia), anemoside B4 (B4)-treated group (2.5, 5, 10 mg/kg), and positive drug group (ribavirin or ceftriaxone sodium injection). Blood samples were collected for hematology analysis. The effects of B4 on inflammation-associated mediators were investigated by Enzyme-linked immunosorbent assay (ELISA) and hematoxylin and eosin staining (HE) staining. Proteins expression was quantified by western blotting.

Results

The network results indicated that many pro-inflammatory cytokines such as tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) participated in anemoside B4’s anti-inflammatory activity. The counts of neutrophil (NEU) and white blood cell (WBC), the level of myeloperoxidase (MPO), and the release of pro-inflammatory cytokines TNF-α, IL-1β, and IL-6 increased by KP or FM1 infection, which were reversed by anemoside B4. In addition, anemoside B4 significantly suppressed the FM1-induced expression of toll-like receptor 4 (TLR4), myeloid differential protein-88 (MyD88), and myeloid differentiation protein-2 (MD-2), which were further validated by molecular docking data that anemoside B4 bound to bioactive sites of TLR4. Therefore, anemoside B4 exhibited a significant therapeutic effect on pneumonia via the TLR4/MyD88 pathway.

Conclusion

Our findings demonstrated that anemoside B4 attenuates pneumonia via the TLR4/Myd88 signaling pathway, suggesting that anemoside B4 is a promising therapeutic candidate for bacterial-infected or viral-infected pneumonia.

The Implication of Oxidative Stress and AMPK-Nrf2 Antioxidative Signaling in Pneumonia Pathogenesis

It is widely recognized that chemical, physical, and biological factors can singly or synergistically evoke the excessive production of oxidative stress in pulmonary tissue that followed by pulmonary lesions and pneumonia. In addition, metabolic and endocrine disorder-induced diseases such as diabetes and obesity often expressed higher susceptibility to pulmonary infections, and presented severe symptoms which increasing the mortality rate. Therefore, the connection between the lesion of the lungs and the metabolic/endocrine disorders is an interesting and essential issue to be addressed. Studies have noticed a similar pathological feature in both infectious pneumonia and metabolic disease-intercurrent pulmonary lesions, that is, from the view of molecular pathology, the accumulation of excessive reactive oxygen species (ROS) in pulmonary tissue accompanying with activated pro-inflammatory signals. Meanwhile, Adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) and nuclear factor erythroid-2-related factor 2 (Nrf2) signaling plays important role in metabolic/endocrine homeostasis and infection response, and it's closely associated with the anti-oxidative capacity of the body. For this reason, this review will start from the summary upon the implication of ROS accumulation, and to discuss how AMPK-Nrf2 signaling contributes to maintaining the metabolic/endocrine homeostasis and attenuates the susceptibility of pulmonary infections.

The long search for a serotype independent pneumococcal vaccine

Introduction: Serotype replacement - a consequence of polysaccharide vaccine use - will continue to drive the inclusion of new serotypes on conjugate vaccines, increasing production complexity and costs, and making an already expensive vaccine less accessible to developing countries, where prevalence is higher and resources available for health systems, scarcer. Serotype-independent formulations are a promising option, but so far they have not been successful in reducing colonization/transmission.Areas covered: Protein-based and whole-cell vaccine candidates studied in the past 30 years. Challenges for serotype-independent vaccine development and alternative approaches.Expert opinion: Clinical trials performed so far demonstrated the importance to establish more reliable animal models and better correlates of protection. Defining appropriate endpoints for clinical trials of serotype-independent vaccine candidates has been a challenge. Inhibition of colonization has been evaluated, but concern on the extent of bacterial elimination is still a matter of debate. Challenges on establishing representative sites for clinical trials, sample sizes and appropriate age groups are discussed. On a whole, although many challenges will have to be overcome, establishing protein-based antigens as serotype-independent vaccines is still the best alternative against the huge burden of pneumococcal diseases in the world.

Long non-coding RNA SNHG16 promotes lipopolysaccharides-induced acute pneumonia in A549 cells via targeting miR-370-3p/IGF2 axis

BACKGROUND

Pneumonia is an infectious lung inflammation in children with high mortality and morbidity rates. Small nucleolar RNA host gene 16 (SNHG16) has been verified to accelerate the progression of acute pneumonia. However, the role of SNHG16 in acute pneumonia has not yet been fully elucidated. The study was aimed to explore the regulatory mechanism of SNHG16 in LPS-induced acute pneumonia in A549 cells.

METHODS

The levels of SNHG16, miR-370-3p and IGF2 in serum samples and LPS-induced A549 cells were detected by quantitative real-time polymerase chain reaction (qRT-PCR). The cell viability and apoptosis of A549 cells were examined by Cell Counting Kit-8 (CCK-8) assay and flow cytometer, respectively. The levels of interleukin 1β (IL-1β), interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α) were determined by enzyme-linked immunosorbent assay (ELISA). The binding relationships among SNHG16, miR-370-3p and IGF2 were predicted by online database and verified by Dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. The protein levels of IGF2 were tested by Western blot.

RESULTS

SNHG16 and IGF2 were upregulated while miR-370-3p was downregulated in serum of acute pneumonia patients and LPS-induced A549 cells. SNHG16 regulated proliferation, apoptosis and inflammatory cytokines by inhibiting miR-370-3p in LPS-induced A549 cells. MiR-370-3p targeted IGF2 and inhibited LPS-induced inflammatory injury via IGF2 in A549 cells. Furthermore, SNHG16 was verified to promote IGF2 expression by sponging miR-370-3p in A549 cells.

CONCLUSION

SNHG16 impeded cell viability and promoted apoptosis, inflammatory injury by targeting IGF2 mediated by miR-370-3p in LPS-induced A549 cells.

Macrolide-Resistant Mycoplasma pneumoniae in the United States as Determined from a National Surveillance Program

There are sparse data to indicate the extent that macrolide-resistant Mycoplasma pneumoniae (MRMp) occurs in the United States or its clinical significance. Between 2015 and 2018, hospitals in 8 states collected and stored respiratory specimens that tested positive for M. pneumoniae and sent them to the University of Alabama at Birmingham, where real-time PCR was performed for detection of 23S rRNA mutations known to confer macrolide resistance. MRMp was detected in 27 of 360 specimens (7.5%). MRMp prevalence was significantly higher in the South and East (18.3%) than in the West (2.1%). A2063G was the predominant 23S rRNA mutation detected. MICs for macrolide-susceptible M. pneumoniae (MSMp) were ≤0.008 μg/ml, whereas MICs for MRMp were 16 to 32 μg/ml. Patients with MRMp infection were more likely to have a history of immunodeficiency or malignancy. Otherwise, there were no other significant differences in the clinical features between patients infected with MRMp and those infected with MSMp, nor were there any differences in radiographic findings, hospitalization rates, viral coinfections, the mean duration of antimicrobial treatment, or clinical outcomes. There was no significant change in MRMp incidence over time or according to age, sex, race/ethnicity, or status as an inpatient or an outpatient. Patients with MRMp were more likely to have received a macrolide prior to presentation, and their treatment was more likely to have been changed to a fluoroquinolone after presentation. This is the first national surveillance program for M. pneumoniae in the United States. Additional surveillance is needed to assess the clinical significance of MRMp and to monitor changes in MRMp prevalence.

Disease severity and clinical outcomes of community-acquired pneumonia caused by non-influenza respiratory viruses in adults: a multicentre prospective registry study from the CAP-China Network

Although broad knowledge of influenza viral pneumonia has been established, the significance of non-influenza respiratory viruses in community-acquired pneumonia (CAP) and their impact on clinical outcomes remains unclear, especially in the non-immunocompromised adult population.Hospitalised immunocompetent patients with CAP were prospectively recruited from 34 hospitals in mainland China. Respiratory viruses were detected by molecular methods. Comparisons were conducted between influenza and non-influenza viral infection groups.In total, 915 out of 2336 adult patients with viral infection were enrolled in the analysis, with influenza virus (28.4%) the most frequently detected virus, followed by respiratory syncytial virus (3.6%), adenovirus (3.3%), human coronavirus (3.0%), parainfluenza virus (2.2%), human rhinovirus (1.8%) and human metapneumovirus (1.5%). Non-influenza viral infections accounted for 27.4% of viral pneumonia. Consolidation was more frequently observed in patients with adenovirus infection. The occurrence of complications such as sepsis (40.1% versus 39.6%; p=0.890) and hypoxaemia (40.1% versus 37.2%; p=0.449) during hospitalisation in the influenza viral infection group did not differ from that of the non-influenza viral infection group. Compared with influenza virus infection, the multivariable adjusted odds ratios of CURB-65 (confusion, urea >7 mmol·L^-1, respiratory rate ≥30 breaths·min^-1, blood pressure <90 mmHg (systolic) or ≤60 mmHg (diastolic), age ≥65 years) ≥3, arterial oxygen tension/inspiratory oxygen fraction <200 mmHg, and occurrence of sepsis and hypoxaemia for non-influenza respiratory virus infection were 0.87 (95% CI 0.26-2.84), 0.72 (95% CI 0.26-1.98), 1.00 (95% CI 0.63-1.58) and 1.05 (95% CI 0.66-1.65), respectively. The hazard ratio of 90-day mortality was 0.51 (95% CI 0.13-1.91).The high incidence of complications in non-influenza viral pneumonia and similar impact of non-influenza respiratory viruses relative to influenza virus on disease severity and outcomes suggest more attention should be given to CAP caused by non-influenza respiratory viruses.

Treatment with andrographolide sulfonate provides additional benefits to imipenem in a mouse model of Klebsiella pneumoniae pneumonia

Klebsiella pneumoniae is a primary cause of community-acquired and nosocomial respiratory infections, and K. pneumoniae resistance to the current treatment approach with carbapenem is worsening. Andrographolide is a natural diterpenoid from Andrographis paniculata that was shown to exert anti-inflammatory activity. We herein show that pretreatment with a water-soluble andrographolide sulfonate significantly attenuate lung injury and infiltration of inflammatory cells. Interestingly, mice receiving combined treatment with andrographolide sulfonate displayed perfect survival rate than the mice treatment with imipenem alone, and monocyte chemotactic protein 5 (MCP-5) level was decreased further. These findings suggest that andrographolide sulfonate could as a potential synergist for antibiotic treatment of bacteria-induced inflammation.

Atypical and Typical Bacteria in Children with Community Acquired Pneumonia

This study seeks to determine the pathogens in respiratory specimens and blood serum obtained from children who present with community acquired pneumonia (CAP) diagnosed on the basis of clinical and radiological evidence. The study group consisted of 46 hospitalized children aged 1-11 years. The material for research consisted of pharyngeal swabs and samples of blood serum. One hundred and thirty eight pharyngeal swabs were examined for the presence of C. pneumoniae antigen, C. pneumoniae DNA, and for typical pathogens. C. pneumoniae DNA was detected in pharyngeal swabs with nested PCR. Classical microbiological culture was used for detection of typical bacteria. ELISA test were used for detection anti-C. pneumoniae and anti-M. pneumoniae antibodies in the serum. C. pneumoniae DNA was identified in 10.9% of children. Positive culture for typical pathogens was observed in 8.7% of children. Specific anti-C. pneumoniae IgM antibodies were found in 8.7% of children, and IgG and IgA antibodies in 1 child each. Specific anti-M. pneumoniae IgG antibodies were found in 13.1% of children and IgM antibodies in 1 child. We conclude that the underlying bacterial etiology of CAP is rather rarely conclusively confirmed in children. Nonetheless, determining the etiology of CAP is essential for the choice of treatment to optimize the use and effectiveness of antimicrobials and to avoid adverse effect. Due to considerable variations in the power of detection of the type of atypical bacteria causing CAP, the search for the optimum diagnostic methods continues.

Peptidoglycan Recognition Protein 2 Regulates Neutrophil Recruitment Into the Lungs After Streptococcus pneumoniae Infection

Peptidoglycan (PGN) recognition proteins (PGLYRPs) are a highly conserved group of host defense proteins in insects and mammals that sense bacterial cell wall PGN and act bactericidally or cleave PGN by amidase function. Streptococcus (S.) pneumoniae is one of the top five killers worldwide and causes, e.g., pneumonia, endocarditis, meningitis and sepsis. S. pneumoniae accounts for approximately 1.5–2 million deaths every year. The risk of antibiotic resistance and a general poor prognosis in young children and elderly people have led to the need for new treatment approaches. To the best of our knowledge, there is no report on the relevance of PGLYRP2 in lung infections. Therefore, we infected mice deficient for PGLYRP2 transnasally with S. pneumoniae and examined the innate immune response in comparison to WT animals. As expected, PGLYRP2-KO animals had to be sacrificed earlier than their WT counterparts, and this was due to higher bacteremia. The higher bacterial load in the PGLYRP2-KO mice was accomplished with lower amounts of proinflammatory cytokines in the lungs. This led to an abolished recruitment of neutrophils into the lungs, the spread of bacteria and the subsequent aggravated course of the disease and early mortality of the PGLYRP2-KO mice. These data suggest a substantial role of PGLYRP2 in the early defense against S. pneumoniae infection, and PGLYRP2 might also affect other infections in the lungs.

Community-acquired Pneumonia Secondary to Legionella pneumophila and Streptococcus pneumoniae: A Rare Co-infection

Community-acquired pneumonia (CAP) is a frequent cause of hospitalization in adults. Streptococcus pneumoniae is the most commonly identified pathogen in CAP whereas Legionella pneumophilia is infrequently identified in CAP. Although co-infections have been previously described, the presence of both pneumococcus and legionella together is rare. We present a patient with positive urinary antigens for both Streptococcus pneumoniae and Legionella pneumophilia serogroup 1, indicating an unusual co-infection.

Urinary antigen testing in community-acquired pneumonia in adults: an update

INTRODUCTION

Community-acquired pneumonia (CAP) continues to be a leading cause of hospitalization and mortality worldwide. Streptococcus pneumoniae and Legionella pneumophila remain the major etiological agents and are responsible for a significant proportion of CAP mortality. Among diagnostic tests for CAP, urine antigen detection of S. pneumoniae and L. pneumophila is widely accepted due to the simplicity of collection and the rapidity of the test results. Areas covered: This comprehensive review outlines the urinary antigen tests available, discusses their sensitivity and specificity, and assesses the usefulness of their results as the basis for targeted therapy. Expert commentary: There have been advances in urine antigen detection tests for patients with CAP. New methodologies show greater sensitivity, detect S. pneumoniae and L. pneumophila in a single test, and also detect pneumococcal serotypes. In addition, urine antigen detection tests have shown a high specificity, which means that a positive result practically indicates the causative pathogen of CAP. Therefore, a positive result can lead to a targeted therapy that is likely to improve patient outcomes and reduce the risk of resistance and adverse events. However, well-designed studies are needed to evaluate the usefulness of urine antigen detection tests with regard to clinical outcomes.

Clinical evaluation of the loop-mediated isothermal amplification assay for the detection of common lower respiratory pathogens in patients with respiratory symptoms

Lower respiratory tract infections (LRTIs) are a substantial public health problem and a leading cause of significant morbidity and mortality worldwide. The aim of this study was to evaluate a commercially available loop-mediated isothermal amplification (LAMP) assay for the simultaneously detection of thirteen common lower respiratory pathogens in patients with respiratory symptoms. All participants age from 1 to 101 years old were recruited from inpatient or outpatient of Meizhou People's Hospital between October 2016 and March 2018. A total of 1767 sputum samples and 88 bronchoalveolar lavage fluid samples from patients with suspected LRTI were collected. For each sample, a parallel study using both routine bacterial culture-based and LAMP assays were carried out. In total, 810 (44.85%) out of the 1855 samples were found to be positive infected with respiratory pathogens by using the LAMP assays. Methicillin-resistant Staphylococcus aureus (MecA) was the most predominant bacterial pathogens, with proportions of 17.09% in sputum and 10.23% bronchoalveolar lavage fluid samples, respectively. The proportions of bacterial pathogen infection with Streptococcus pneumoniae (Spn) (24.24%) was relatively high in aged <15 group (P <.001) while the proportions of bacterial pathogen infection with MecA (22.89%) was relatively high in aged >60 group (P <.001). Bacterial pathogen infection with MecA having the highest prevalence with proportions of 17.81% and 13.94% in male and female, respectively. A statistically higher proportion of male group had bacterial pathogen infection with Pseudomonas aeruginosa (Pae) in this study (P = .035). Comparison of results between the LAMP assay and culture method was conducted and our results indicated that there was higher detection rate by the LAMP assay than the bacterial culture method. Comparison of the results obtained with the LAMP assay and those obtained by sequencing analysis, when the sequencing method was set to 100%, demonstrating that the LAMP assay is 100% specific and 95.50% sensitive. The technique of LAMP assay was proved to be a simple, sensitive, specific, convenient, and rapid method, which can be implemented for diagnosing pathogenic bacteria in patients with LRTIs in primary labs without any need for expensive equipment or specialized techniques in resource-limited areas of China.

Cytokine responses, microbial aetiology and short-term outcome in community-acquired pneumonia

BACKGROUND

The inflammatory response to community-acquired pneumonia (CAP) is orchestrated through activation of cytokine networks and the complement system. We examined the association of multiple cytokines and the terminal complement complex (TCC) with microbial aetiology, disease severity and short-term outcome.

MATERIALS AND METHODS

Plasma levels of 27 cytokines and TCC were analysed in blood samples obtained at hospital admission, clinical stabilization and 6-week follow-up from 247 hospitalized adults with CAP. Fourteen mediators were included in final analyses. Adverse short-term outcome was defined as intensive care unit (ICU) admission and 30-day mortality.

RESULTS

Cytokine and TCC levels were dynamic in the clinical course of CAP, with highest levels seen at admission for most mediators. Admission levels of cytokines and TCC did not differ between groups of microbial aetiology. High admission levels of IL-6 (odds ratio [OR] 1.47, 95% confidence interval [CI] 1.18-1.84, P = .001), IL-8 (OR 1.79, 95% CI 1.26-2.55, P = .001) and MIP-1β (OR 2.28, 95% CI 1.36-3.81, P = .002) were associated with a CURB-65 severity score of ≥3, while IL-6 (OR 1.37, 95% CI 1.07-1.74, P = .011) and MIP-1β (OR 1.86, 95% CI 1.03-3.36, P = .040) were associated with a high risk of an adverse short-term outcome.

CONCLUSIONS

In this CAP cohort, admission levels of IL-6, IL-8 and MIP-1β were associated with disease severity and/or adverse short-term outcome. Still, for most mediators, only nonsignificant variations in inflammatory responses were observed for groups of microbial aetiology, disease severity and short-term outcome.

Mycoplasma pneumoniae from the Respiratory Tract and Beyond

Mycoplasma pneumoniae is an important cause of respiratory tract infections in children as well as adults that can range in severity from mild to life-threatening. Over the past several years there has been much new information published concerning infections caused by this organism. New molecular-based tests for M. pneumoniae detection are now commercially available in the United States, and advances in molecular typing systems have enhanced understanding of the epidemiology of infections. More strains have had their entire genome sequences published, providing additional insights into pathogenic mechanisms. Clinically significant acquired macrolide resistance has emerged worldwide and is now complicating treatment. In vitro susceptibility testing methods have been standardized, and several new drugs that may be effective against this organism are undergoing development. This review focuses on the many new developments that have occurred over the past several years that enhance our understanding of this microbe, which is among the smallest bacterial pathogens but one of great clinical importance.

Simultaneous Detection of Nine Key Bacterial Respiratory Pathogens Using Luminex xTAG® Technology

Early diagnosis and treatment are crucial to the outcome of lower respiratory tract infections (LRTIs). In this study, we developed an assay combining multiplex PCR and Luminex technology (MPLT) for the detection of nine important respiratory bacterial pathogens, which frequently cause LRTIs. These were Streptococcus pneumoniae, Moraxella catarrhalis, Staphylococcus aureus, Streptococcus pyogenes, Haemophilus influenzae, Mycoplasma pneumoniae, Legionella spp., Pseudomonas aeruginosa, and Klebsiella pneumoniae. Through the hybridization reaction between two new synthesized multiplex PCR products and MagPlex-TAG Microspheres, we demonstrate that the detection limits for these nine pathogens were as low as 10²–10³ CFU/mL. Furthermore, 86 clinical bronchoalveolar lavage fluid specimens were used to evaluate this method. Compared with the results of nine simplex real-time PCR reactions targeting these nine pathogens, this MPLT assay demonstrated a high diagnostic accuracy for Streptococcus pneumoniae (sensitivity, 87.5% and specificity, 100%). Furthermore, sensitivity and specificity for the other eight pathogens all attained 100% diagnostic accuracy. In addition, the consistency between MPLT and the nine real-time PCR reactions exceeded 98.8%. In conclusion, MPLT is a high-throughput, labor-saving and reliable method with high sensitivity and specificity for identifying nine respiratory pathogens responsible for LRTIs. Indeed, this assay may be a promising supplement to conventional methods used to diagnose LRTIs.

Antibiotic stewardship in community-acquired pneumonia

INTRODUCTION

Community-acquired pneumonia (CAP) continues to be associated with significant mortality and morbidity. As with other infectious diseases, in recent years there has been a marked increase in resistance to the antibiotics commonly used against the pathogens that cause CAP. Antimicrobial stewardship denotes coordinated interventions to improve and measure the appropriate use of antibiotics by encouraging the selection of optimal drug regimens. Areas covered: Several elements can be applied to antibiotic stewardship strategies for CAP in order to maintain or improve patient outcomes. In this regard, antibiotic de-escalation, duration of antibiotic treatment, adherence to CAP guidelines recommendations about empirical treatment, and switching from intravenous to oral antibiotic therapy may each be relevant in this context. Antimicrobial stewardship strategies, such as prospective audit with intervention and feedback, clinical pathways, and dedicated multidisciplinary teams, that have included some of these elements have demonstrated improvements in antimicrobial use for CAP without negatively affecting clinical outcomes. Expert commentary: Although there are a limited number of randomized clinical studies addressing antimicrobial stewardship strategies in CAP, there is evidence that antibiotic stewardship initiatives can be securely applied, providing benefits to both healthcare systems and patients.

Efficacy and Safety of Adjunctive Corticosteroids Therapy for Severe Community-Acquired Pneumonia in Adults: An Updated Systematic Review and Meta-Analysis

BACKGROUND

Adjunctive corticosteroids therapy is an attractive option for community-acquired pneumonia (CAP) treatment. However, the effectiveness of adjunctive corticosteroids on mortality of CAP remains inconsistent, especially in severe CAP. We performed a meta-analysis to evaluate the efficacy and safety of adjunctive corticosteroids in severe CAP patients.

METHODS

Three databases of PubMed, EMBASE and Cochrane Library were searched for related studies published in English up to December, 2015. Randomized controlled trials (RCTs) of corticosteroids in hospitalized adults with severe CAP were included. Meta-analysis was performed by a random-effect model with STATA 11.0 software. We estimated the summary risk ratios (RRs) or effect size (ES) with its corresponding 95% confidence interval (95%CI) to assess the outcomes.

RESULTS

We included 8 RCTs enrolling 528 severe CAP patients. Adjunctive corticosteroids significantly reduced all-cause mortality (RR = 0.46, 95%CI: 0.28 to 0.77, p = 0.003), risk of adult respiratory distress syndrome (ARDS) (RR = 0.23, 95%CI: 0.07 to 0.80, p = 0.02) and need for mechanical ventilation (RR = 0.50, 95%CI: 0.27 to 0.92, p = 0.026). Adjunctive corticosteroids did not increase frequency of hyperglycemia requiring treatment (RR = 1.03, 95%CI: 0.61 to 1.72, p = 0.91) or gastrointestinal hemorrhage (RR = 0.66, 95%CI: 0.19 to 2.31, p = 0.52). In subgroup analysis by duration of corticosteroids, we found that prolonged corticosteroids therapy significantly reduced all-cause mortality (RR = 0.41, 95%CI: 0.20 to 0.83, p = 0.01) and length of hospital stay (-4.76 days, 95% CI:-8.13 to -1.40, p = 0.006).

CONCLUSIONS

Results from this meta-analysis suggested that adjunctive corticosteroids therapy was safe and beneficial for severe CAP. In addition, prolonged corticosteroids therapy was more effective. These results should be confirmed by adequately powered studies in the future.

Solithromycin for the treatment of community-acquired bacterial pneumonia

INTRODUCTION

Community-acquired pneumonia is a major public health problem worldwide. In recent years, there has been an increase in the frequency of resistance to the antimicrobials such as β-lactams or macrolides which have habitually been used against the causative pathogens. Solithromycin, a next-generation macrolide, is the first fluoroketolide with activity against most of the frequently isolated bacteria in community-acquired pneumonia, including typical and atypical bacteria as well as macrolide-resistant Streptococcus pneumoniae. Areas covered: A detailed assessment of the literature relating to the antimicrobial activity, pharmacokinetic/pharmacodynamic properties, efficacy, tolerability and safety of solithromycin for the treatment of community-acquired bacterial pneumonia Expert commentary: Recent randomized controlled phase II/III trials have demonstrated the equivalent efficacy of oral and intravenous solithromycin compared with fluoroquinolones in patients with lower mild-to-moderate respiratory infections, and have shown that systemic adverse events are comparable between solithromycin and alternative treatments. However, studies of larger populations which are able to identify infrequent adverse events are now needed to confirm these findings. On balance, current data supports solithromycin as a promising therapy for empirical treatment in adults with community-acquired bacterial pneumonia.

In Vivo Pharmacodynamic Target Assessment of Delafloxacin against Staphylococcus aureus, Streptococcus pneumoniae, and Klebsiella pneumoniae in a Murine Lung Infection Model

Delafloxacin is a broad-spectrum anionic fluoroquinolone under development for the treatment of bacterial pneumonia. The goal of the study was to determine the pharmacokinetic/pharmacodynamic (PK/PD) targets in the murine lung infection model for Staphylococcus aureus, Streptococcus pneumoniae, and Klebsiella pneumoniae Four isolates of each species were utilized for in vivo studies: for S. aureus, one methicillin-susceptible and three methicillin-resistant isolates; S. pneumoniae, two penicillin-susceptible and two penicillin-resistant isolates; K. pneumoniae, one wild-type and three extended-spectrum beta-lactamase-producing isolates. MICs were determined using CLSI methods. A neutropenic murine lung infection model was utilized for all treatment studies, and drug dosing was by the subcutaneous route. Single-dose plasma pharmacokinetics was determined in the mouse model after administration of 2.5, 10, 40, and 160 mg/kg. For in vivo studies, 4-fold-increasing doses of delafloxacin (range, 0.03 to 160 mg/kg) were administered every 6 h (q6h) to infected mice. Treatment outcome was measured by determining organism burden in the lung (CFU counts) at the end of each experiment (24 h). The Hill equation for maximum effect (Emax) was used to model the dose-response data. The magnitude of the PK/PD index, the area under the concentration-time curve over 24 h in the steady state divided by the MIC (AUC/MIC), associated with net stasis and 1-log kill endpoints was determined in the lung model for all isolates. MICs ranged from 0.004 to 1 mg/liter. Single-dose PK parameter ranges include the following: for maximum concentration of drug in serum (Cmax), 2 to 70.7 mg/liter; AUC from 0 h to infinity (AUC0-∞), 2.8 to 152 mg · h/liter; half-life (t1/2), 0.7 to 1 h. At the start of therapy mice had 6.3 ± 0.09 log10 CFU/lung. In control mice the organism burden increased 2.1 ± 0.44 log10 CFU/lung over the study period. There was a relatively steep dose-response relationship observed with escalating doses of delafloxacin. Maximal organism reductions ranged from 2 log10 to more than 4 log10 The median free-drug AUC/MIC magnitude associated with net stasis for each species group was 1.45, 0.56, and 40.3 for S. aureus, S. pneumoniae, and K. pneumoniae, respectively. AUC/MIC targets for the 1-log kill endpoint were 2- to 5-fold higher. Delafloxacin demonstrated in vitro and in vivo potency against a diverse group of pathogens, including those with phenotypic drug resistance to other classes. These results have potential relevance for clinical dose selection and evaluation of susceptibility breakpoints for delafloxacin for the treatment of lower respiratory tract infections involving these pathogens.

Relevant Cytokines in the Management of Community-Acquired Pneumonia

Community-acquired pneumonia (CAP) is the leading cause of infectious death in the world. Immune dysregulation during acute lung infection plays a role in lung injury and the systemic inflammatory response. Cytokines seem to be major players in severe lung infection cases. Here, we present a review of published papers in the last 3 years regarding this topic. The cytokine response during pneumonia is different in bacterial vs viral infections; some of these cytokines correlate with clinical severity scales such as CURB65 or SOFA. Treatment focused in the cytokine environment is an interesting area that could impact the prognosis of CAP. Some of the agents that have been studied as co-adjuvant therapy are corticosteroids, macrolides, and linezolid, but anyone of those have shown a clear or proven efficacy or have been recommended as a part of the standard of care for CAP. More studies designed to define the role of immunomodulatory agents, such as co-adjuvant therapy in pneumonia, are needed.