Addition of a macrolide to a beta-lactam-based empirical antibiotic regimen is associated with lower in-hospital mortality for patients with bacteremic pneumococcal pneumonia

Analysis of the effectiveness of combination antimicrobial therapy for Legionnaires' disease: A nationwide inpatient database study

OBJECTIVES

The effectiveness of monotherapy and combination therapy with quinolones and macrolides for treating Legionnaires' disease remains uncertain; this study aimed to assess the comparative effectiveness of three treatment approaches.

METHODS

Using a nationwide inpatient database, we analyzed 3560 eligible patients hospitalized for Legionnaires' disease between April 1, 2014, and March 31, 2021; patients were divided into combination therapy, quinolone monotherapy, and macrolide monotherapy groups according to the antibiotics administered within 2 days of admission. We compared in-hospital mortality, total hospitalization costs, and length of stay across these groups using multiple propensity score analysis with inverse probability of treatment weighting.

RESULTS

Of the 3560 patients, there were 564 (15.8%), 2221 (62.4%), and 775 (21.8%) patients in the combination therapy, quinolone monotherapy, and macrolide monotherapy groups, respectively. No significant differences were observed in in-hospital mortality between combination therapy and quinolone monotherapy groups, and between combination therapy and macrolide monotherapy groups. There were no significant differences in total hospitalization costs or length of stay among the three groups.

CONCLUSION

The study suggests that there may not be a significant advantage in using a combination of quinolones and macrolides over monotherapy for the treatment of Legionnaires' disease. Given the potential for increased side effects, careful consideration is advised when choosing this combination therapy.

Azalomycin F4a targets peptidoglycan synthesis of Gram-positive bacteria revealed by high-throughput CRISPRi-seq analysis

Azalomycin F4a is a promising 36-membered polyhydroxy macrolide that shows antibacterial activity against drug-resistant Gram-positive bacteria, but its exact working mechanism remains to be elusive. Here, we isolated the azalomycin F4a product from a Streptomyces solisilvae and demonstrated its antibacterial activity against Gram-positive pathogens including Streptococcus pneumoniae, Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA). We further showed that combination of azalomycin F4a with methicillin has an additive antimicrobial effect on MRSA, where the minimal inhibitory concentrations (MIC) of methicillin to MRSA was decreased by 1000-fold in the presence of sublethal concentration of azalomycin F4a. A CRISPRi-seq based whole genome screen was employed to identify the potential targets of azalomycin F4a, which revealed that peptidoglycan synthesis (PGS) was inhibited by azalomycin F4a. Furthermore, azalomycin F4a treatment could significantly impair S. aureus biofilm formation. Our research highlights that cell wall synthesis is an additional target for novel classes of macrolide besides ribosome.

Advancements in the Management of Severe Community-Acquired Pneumonia: A Comprehensive Narrative Review

Pneumonia, classified as a lower respiratory tract illness, affects different parts of the bronchial system as well as alveoli and can present with varying severities depending on co-morbidities and causative pathogens. It can be broadly classified using the setting in which it was acquired, namely the community or hospital setting, the former being more common and spreading through person-to-person droplet transmission. Community-acquired pneumonia (CAP) is currently the fourth leading cause of death worldwide, and its high mortality makes continual insight into the management of the condition worthwhile. This review explores the literature specifically for severe CAP (sCAP) and delves into the diagnosis, various modalities of treatment, and management of the condition. This condition can be defined as pneumonia requiring mechanical ventilation in the ICU and/or presenting with sepsis and organ failure due to pneumonia. The disease process is characterized by inflammation of the lung parenchyma, initiated by a combination of pathogens and lowered local defenses. Acute diagnosis of the condition is vital in reducing negative patient outcomes, namely through clinical presentation, blood/sputum cultures, imaging modalities such as computed tomography scan, and inflammatory markers, identifying common causative pathogens such as Streptococcus pneumoniae, rhinovirus, Legionella, and viral influenza. Pathogens such as Escherichia coli should also be investigated in patients with chronic obstructive pulmonary disease. The mainstay of treating sCAP includes rapid ICU admission once a diagnosis has been confirmed, initiating sepsis protocol, and treatment with combined empiric antibiotic regimens consisting of beta-lactams and macrolides. Corticosteroid use alongside antibiotics shows promise in reducing inflammation, but its use has to be judged on a case-by-case basis. New drugs such as omadacycline, delafloxacin, and zabofloxacin have shown valid evidence for the treatment of resistant causative organisms. The main guidelines for preventing sCAP include maintaining a healthy lifestyle, and annual pneumococcal and influenza vaccines are recommended for the most vulnerable patient groups, such as those with COPD and immunosuppression.

Ceftaroline: Systematic Review of Clinical Uses and Emerging Drug Resistance

OBJECTIVE

To assess the success rates of off-label uses of ceftaroline for infections caused by methicillin-resistant Staphylococcus aureus (MRSA) and evaluate emerging ceftaroline resistance.

DATA SOURCES

We queried PubMed/MEDLINE, with the search term "Ceftaroline." Articles were restricted to the English language and year of publication (January 1, 2009-January 31, 2022).

STUDY SELECTION AND DATA EXTRACTION

Clinical trials, observational studies, and case reports that reported efficacy, safety, pharmacokinetics, use in MRSA infections other than acute bacterial skin infection and community-acquired pneumonia, and ceftaroline resistance were selected.

DATA SYNTHESIS

The search pooled 103 publications and all abstracts were reviewed. Forty-six articles that reported efficacy, safety, pharmacokinetics, or off-label use in multiple patients and 7 articles on ceftaroline resistance are used in this review. Ceftaroline has been approved for treatment of acute skin/soft tissue infection and community-acquired pneumonia. Ceftaroline's efficacy in off-label infections ranged from 66.7% to 87.3% depending on the types of infection. There were 14 documented cases of ceftaroline resistance associated with PBP2a changes.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

Case series and observational studies have documented success with ceftaroline alone or in combination with vancomycin or daptomycin for treatment of MRSA bone and joint, endovascular, diabetic foot infections, and bacteremia from other causes.

CONCLUSION

Despite the lack of randomized controlled trials, ceftaroline is used as salvage therapy for different MRSA infections. The data from case series and observational studies are promising but ceftaroline should be used judiciously as ceftaroline-resistant MRSA begin to emerge.

The Effect of Macrolides on Mortality in Bacteremic Pneumococcal Pneumonia: A Retrospective, Nationwide Cohort Study, Israel, 2009-2017

BACKGROUND

Previous cohort studies of pneumonia patients reported lower mortality with advanced macrolides. Our aim was to characterize antibiotic treatment patterns and assess the role of quinolones or macrolides in empirical therapy.

MATERIALS

An historical cohort, 1 July 2009 to 30 June 2017, included, through active surveillance, all culture-confirmed bacteremic pneumococcal pneumonia (BPP) among adults in Israel. Cases without information on antibiotic treatment were excluded. Logistic regression analysis was used to assess independent predictors of in-hospital mortality.

RESULTS

A total of 2016 patients with BPP were identified. The median age was 67.2 years (interquartile range [IQR] 53.2-80.6); 55.1% were men. Lobar pneumonia was present in 1440 (71.4%), multi-lobar in 576 (28.6%). Median length of stay was 6 days (IQR 4-11). A total of 1921 cases (95.3%) received empiric antibiotics with anti-pneumococcal coverage: ceftriaxone, in 1267 (62.8%). Coverage for atypical bacteria was given to 1159 (57.5%), 64% of these, with macrolides. A total of 372 (18.5%) required mechanical ventilation, and 397 (19.7%) died. Independent predictors of mortality were age (odds ratio [OR] 1.051, 95% confidence interval [CI] 1.039, 1.063), being at high-risk for pneumococcal disease (OR 2.040, 95% CI 1.351, 3.083), multi-lobar pneumonia (OR 2.356, 95% CI 1.741, 3.189). Female sex and macrolide therapy were predictors of survival: (OR 0.702, 95% CI .516, .955; and OR 0.554, 95% CI .394, .779, respectively). Either azithromycin or roxithromycin treatment for as short as two days was predictor of survival. Quinolone therapy had no effect.

CONCLUSIONS

Empirical therapy with macrolides reduced odds for mortality by 45%. This effect was evident with azithromycin and with roxithromycin. The effect did not require a full course of therapy.

Community-Acquired Pneumonia

Community-acquired pneumonia is an important cause of morbidity and mortality. It can be caused by bacteria, viruses, or fungi and can be prevented through vaccination with pneumococcal, influenza, and COVID-19 vaccines. Diagnosis requires suggestive history and physical findings in conjunction with radiographic evidence of infiltrates. Laboratory testing can help guide therapy. Important issues in treatment include choosing the proper venue, timely initiation of the appropriate antibiotic or antiviral, appropriate respiratory support, deescalation after negative culture results, switching to oral therapy, and short treatment duration.

Comparison of prognostic factors between bacteraemic and non-bacteraemic critically ill immunocompetent patients in community-acquired severe pneumococcal pneumonia: a STREPTOGENE sub-study

Background

The presence of bacteraemia in pneumococcal pneumonia in critically ill patients does not appear to be a strong independent prognostic factor in the existing literature. However, there may be a specific pattern of factors associated with mortality for ICU patients with bacteraemic pneumococcal community-acquired pneumonia (CAP). We aimed to compare the factors associated with mortality, according to the presence of bacteraemia or not on admission, for patients hospitalised in intensive care for severe pneumococcal CAP.

Methods

This was a post hoc analysis of data from the prospective, observational, multicentre STREPTOGENE study in immunocompetent Caucasian adults admitted to intensive care in France between 2008 and 2012 for pneumococcal CAP. Patients were divided into two groups based on initial blood culture (positive vs. negative) for Streptococcus pneumoniae. The primary outcome was hospital mortality, which was compared between the two groups using odds ratios according to predefined variables to search for a prognostic interaction present in bacterial patients but not non-bacteraemic patients. Potential differences in the distribution of serotypes between the two groups were assessed. The prognostic consequences of the presence or not of initial bi-antibiotic therapy were assessed, specifically in bacteraemic patients.

Results

Among 614 included patients, 274 had a blood culture positive for S. pneumoniae at admission and 340 did not. The baseline difference between the groups was more frequent leukopaenia (26% vs. 14%, p = 0.0002) and less frequent pre-hospital antibiotic therapy (10% vs. 16.3%, p = 0.024) for the bacteraemic patients. Hospital mortality was not significantly different between the two groups (p = 0.11). We did not observe any prognostic factors specific to the bacteraemic patient population, as the statistical comparison of the odds ratios, as an indication of the association between the predefined prognostic parameters and mortality, showed them to be similar for the two groups. Bacteraemic patients more often had invasive serotypes but less often serotypes associated with high case fatality rates (p = 0.003). The antibiotic regimens were similar for the two groups. There was no difference in mortality for patients in either group given a beta-lactam alone vs. a beta-lactam combined with a macrolide or fluoroquinolone.

Conclusion

Bacteraemia had no influence on the mortality of immunocompetent Caucasian adults admitted to intensive care for severe pneumococcal CAP, regardless of the profile of the associated prognostic factors.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-021-00936-z.

Comparative efficacy of azithromycin versus clarithromycin in combination with beta-lactams to treat community-acquired pneumonia in hospitalized patients: a systematic review

OBJECTIVE

The objective was to compare the efficacy of azithromycin and clarithromycin in combination with beta-lactams to treat community-acquired pneumonia among hospitalized adults.

METHODS

Five databases (PubMed, Google Scholar, Trip, Medline, and Clinical Key) were searched to identify randomized clinical trials with patients exposed to azithromycin or clarithromycin in combination with a beta-lactam. All articles were critically reviewed for inclusion in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

Seven clinical trials were included. The treatment success rate for azithromycin-beta-lactam after 10 to 14 days was 87.55% and that for clarithromycin-beta-lactam after 5 to 7 days of therapy was 75.42%. Streptococcus pneumoniae was commonly found in macrolide groups, with 130 and 80 isolates in the clarithromycin-based and azithromycin-based groups, respectively. The length of hospital stay was an average of 8.45 days for patients receiving a beta-lactam-azithromycin combination and 7.25 days with a beta-lactam-clarithromycin combination.

CONCLUSION

Macrolide inter-class differences were noted, with a higher clinical success rate for azithromycin-based combinations. However, a shorter length of hospital stay was achieved with a clarithromycin-beta-lactam regimen. Thus, a macrolide combined with a beta-lactam should be chosen using susceptibility data from the treating facility.

Lemierre's syndrome caused by Klebsiella pneumoniae: A case report

BACKGROUND

Lemierre's syndrome is a disease that causes anaerobic sepsis, internal jugular vein thrombosis, and septic embolism in the lungs and other organs after acute oropharyngeal infection. It was named after André-Alfred Lemierre in 1936.

CASE SUMMARY

Here, we have reported a case of Lemierre’s syndrome in a 56-year-old female patient who presented with a sore throat. The patient had septic shock, had not voided, and had severe hyperglycemia at the time of her visit. Imaging tests revealed bilateral pneumonia, pleural effusion, pulmonary embolism, and renal vein thrombosis. The patient was admitted to the intensive care unit and placed on mechanical ventilation due to acute respiratory distress syndrome. Continuous renal replacement therapy was administered to treat renal failure with anuria. Klebsiella pneumoniae was cultured from blood and sputum samples. After reviewing various results, the patient was ultimately diagnosed with Lemierre’s syndrome. The patient was treated with appropriate antibiotics and thrombolytic agents. She was discharged from the hospital after recovery.

CONCLUSION

Lemierre’s syndrome is associated with a high mortality rate. Therefore, clinicians should be familiar with the signs and symptoms of this disease as well as the preemptive examinations, procedures, and treatments.

Cracking the Challenge of Antimicrobial Drug Resistance with CRISPR/Cas9, Nanotechnology and Other Strategies in ESKAPE Pathogens

Antimicrobial resistance is mushrooming as a silent pandemic. It is considered among the most common priority areas identified by both national and international agencies. The global development of multidrug-resistant strains now threatens public health care improvement by introducing antibiotics against infectious agents. These strains are the product of both continuous evolution and unchecked antimicrobial usage (AMU). The ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) are the leading cause of nosocomial infections throughout the world. Most of them are now multidrug-resistant, which pose significant challenges in clinical practice. Understanding these bacteria’s resistance mechanisms is crucial for developing novel antimicrobial agents or other alternative tools to fight against these pathogens. A mechanistic understanding of resistance in these pathogens would also help predict underlying or even unknown mechanisms of resistance of other emerging multidrug-resistant pathogens. Research and development to find better antibacterial drugs and research on tools like CRISPER-Cas9, vaccines, and nanoparticles for treatment of infections that can be further explored in the clinical practice health sector have recognized these alternatives as essential and highly effective tools to mitigate antimicrobial resistance. This review summarizes the known antimicrobial resistance mechanisms of ESKAPE pathogens and strategies for overcoming this resistance with an extensive overview of efforts made in this research area.

Invasive Pneumococcal Disease in a Patient With COVID-19: A Case Report

The spread of the new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19), has resulted in a global health pandemic and caused profound morbidity and mortality worldwide. The virus is known to cause severe hypoxemic respiratory failure and has been associated with extrapulmonary manifestations and end-organ dysfunction in the setting of extensive inflammatory response. Recently, the association between COVID-19 and pneumococcal pneumonia co-infection or superinfections has gained increasing interest. In this report, we present the case of a 58-year-old man with a past medical history significant for pulmonary tuberculosis, diagnosed over two decades ago, who presented with pleuritic chest pain, myalgia, intermittent fevers, chills, and productive cough and was found to have invasive pneumococcal disease and COVID-19. To our knowledge, this is the first reported case of invasive pneumococcal infection in a patient with COVID-19.

C-Reactive Protein-Based Strategy to Reduce Antibiotic Dosing for the Treatment of Pneumococcal Infection

C-reactive protein (CRP) is a component of innate immunity. The concentration of CRP in serum increases in microbial infections including Streptococcus pneumoniae infection. Employing a mouse model of pneumococcal infection, it has been shown that passively administered human wild-type CRP protects mice against infection, provided that CRP is injected into mice within two hours of administering pneumococci. Engineered CRP (E-CRP) molecules have been reported recently; unlike wild-type CRP, passively administered E-CRP protected mice against infection even when E-CRP was injected into mice after twelve hours of administering pneumococci. The current study was aimed at comparing the protective capacity of E-CRP with that of an antibiotic clarithromycin. We established a mouse model of pneumococcal infection in which both E-CRP and clarithromycin, when used alone, provided minimal but equal protection against infection. In this model, the combination of E-CRP and clarithromycin drastically reduced bacteremia and increased survival of mice when compared to the protective effects of either E-CRP or clarithromycin alone. E-CRP was more effective in reducing bacteremia in mice treated with clarithromycin than in untreated mice. Also, there was 90% reduction in antibiotic dosing by including E-CRP in the antibiotic-treatment for maximal protection of infected mice. These findings provide an example of cooperation between the innate immune system and molecules that prevent multiplication of bacteria, and that should be exploited to develop novel combination therapies for infections against multidrug-resistant pneumococci. The reduction in antibiotic dosing by including E-CRP in the combination therapy might also resolve the problem of developing antibiotic resistance.

Progress in the mechanism and targeted drug therapy for COPD

Chronic obstructive pulmonary disease (COPD) is emphysema and/or chronic bronchitis characterised by long-term breathing problems and poor airflow. The prevalence of COPD has increased over the last decade and the drugs most commonly used to treat it, such as glucocorticoids and bronchodilators, have significant therapeutic effects; however, they also cause side effects, including infection and immunosuppression. Here we reviewed the pathogenesis and progression of COPD and elaborated on the effects and mechanisms of newly developed molecular targeted COPD therapeutic drugs. Among these new drugs, we focussed on thioredoxin (Trx). Trx effectively prevents the progression of COPD by regulating redox status and protease/anti-protease balance, blocking the NF-κB and MAPK signalling pathways, suppressing the activation and migration of inflammatory cells and the production of cytokines, inhibiting the synthesis and the activation of adhesion factors and growth factors, and controlling the cAMP-PKA and PI3K/Akt signalling pathways. The mechanism by which Trx affects COPD is different from glucocorticoid-based mechanisms which regulate the inflammatory reaction in association with suppressing immune responses. In addition, Trx also improves the insensitivity of COPD to steroids by inhibiting the production and internalisation of macrophage migration inhibitory factor (MIF). Taken together, these findings suggest that Trx may be the ideal drug for treating COPD.

Treatment of severe pneumonia by hinokitiol in a murine antimicrobial-resistant pneumococcal pneumonia model

Streptococcus pneumoniae is often isolated from patients with community-acquired pneumonia. Antibiotics are the primary line of treatment for pneumococcal pneumonia; however, rising antimicrobial resistance is becoming more prevalent. Hinokitiol, which is isolated from trees in the cypress family, has been demonstrated to exert antibacterial activity against S. pneumoniae in vitro regardless of antimicrobial resistance. In this study, the efficacy of hinokitiol was investigated in a mouse pneumonia model. Male 8-week-old BALB/c mice were intratracheally infected with S. pneumoniae strains D39 (antimicrobial susceptible) and NU4471 (macrolide resistant). After 1 h, hinokitiol was injected via the tracheal route. Hinokitiol significantly decreased the number of S. pneumoniae in the bronchoalveolar lavage fluid (BALF) and the concentration of pneumococcal DNA in the serum, regardless of whether bacteria were resistant or susceptible to macrolides. In addition, hinokitiol decreased the infiltration of neutrophils in the lungs, as well as the concentration of inflammatory cytokines in the BALF and serum. Repeated hinokitiol injection at 18 h intervals showed downward trend in the number of S. pneumoniae in the BALF and the concentration of S. pneumoniae DNA in the serum with the number of hinokitiol administrations. These findings suggest that hinokitiol reduced bacterial load and suppressed excessive host immune response in the pneumonia mouse model. Accordingly, hinokitiol warrants further exploration as a potential candidate for the treatment of pneumococcal pneumonia.

Exploring metabolic adaptation of Streptococcus pneumoniae to antibiotics

The Gram-positive bacterium Streptococcus pneumoniae is one of the common causes of community acquired pneumonia, meningitis, and otitis media. Analyzing the metabolic adaptation toward environmental stress conditions improves our understanding of its pathophysiology and its dependency on host-derived nutrients. In this study, extra- and intracellular metabolic profiles were evaluated to investigate the impact of antimicrobial compounds targeting different pathways of the metabolome of S. pneumoniae TIGR4Δcps. For the metabolomics approach, we analyzed the complex variety of metabolites by using ¹H NMR, HPLC-MS, and GC–MS as different analytical techniques. Through this combination, we detected nearly 120 metabolites. For each antimicrobial compound, individual metabolic effects were detected that often comprised global biosynthetic pathways. Cefotaxime altered amino acids metabolism and carbon metabolism. The purine and pyrimidine metabolic pathways were mostly affected by moxifloxacin treatment. The combination of cefotaxime and azithromycin intensified the stress response compared with the use of the single antibiotic. However, we observed that three cell wall metabolites were altered only by treatment with the combination of the two antibiotics. Only moxifloxacin stress-induced alternation in CDP-ribitol concentration. Teixobactin-Arg10 resulted in global changes of pneumococcal metabolism. To meet the growing requirements for new antibiotics, our metabolomics approach has shown to be a promising complement to other OMICs investigations allowing insights into the mode of action of novel antimicrobial compounds.

Antimicrobial Therapy in the Context of the Damage-Response Framework: the Prospect of Optimizing Therapy by Reducing Host Damage

By design, antimicrobial agents act directly on microbial targets. These drugs aim to eliminate microbes and are remarkably effective against susceptible organisms. Nonetheless, some patients succumb to infectious diseases despite appropriate antimicrobial therapy. Today, with very few exceptions, physicians select antimicrobial therapy based on its activity against the targeted organism without consideration of how the regimen affects patients' immune responses. An important concept to emerge in the past few decades is that immune responses to microbes can be detrimental by enhancing host damage, which can translate into clinical disease. A central tenet of the damage-response framework (DRF) of microbial pathogenesis is that the relevant outcome of host-microbe interaction is the damage that occurs in the host, which can be due to microbial factors, host factors, or both. Given that host damage can make patients sick, reducing it should be a goal of treating infectious diseases. Inflammation and damage that stem from the host response to an infectious disease can increase during therapy with some antimicrobial agents and decrease during therapy with others. When a patient cannot eliminate a microbe with their own immune response, antimicrobial therapy is essential for microbial elimination, and yet it can affect the inflammatory response. In this essay, we discuss antimicrobial therapy in the context of the DRF and propose that consideration of the DRF may help tailor therapy to a patient's need to augment or reduce inflammation.

Azithromycin combination therapy for community-acquired pneumonia: propensity score analysis

Whether macrolide combination therapy reduces the mortality of patients with severe community-acquired pneumonia (CAP) hospitalized in the non-intensive care unit (ICU) remains unclear. Therefore, we investigated the efficacy of adding azithromycin to β-lactam antibiotics for such patients. This prospective cohort study enrolled consecutive patients with CAP hospitalized in the non-ICU between October 2010 and November 2016. The 30-day mortality between β-lactam and azithromycin combination therapy and β-lactam monotherapy was compared in patients classified as mild to moderate and severe according to the CURB-65, Pneumonia Severity Index (PSI), and Infectious Diseases Society of America (IDSA)/American Thoracic Society (ATS) criteria. Inverse probability of treatment weighting (IPTW) analysis was used to reduce biases. Based on the CURB-65 and PSI, combination therapy did not significantly reduce the 30-day mortality in either group (179 patients in the combination group, 952 in the monotherapy group). However, based on the IDSA/ATS criteria, combination therapy significantly reduced the 30-day mortality in patients with severe (odds ratio [OR] 0.12, 95% confidence interval [CI] 0.007–0.57), but not non-severe pneumonia (OR 1.85, 95% CI 0.51–5.40); these results were similar after IPTW analysis. Azithromycin combination therapy significantly reduced the mortality of patients with severe CAP who met the IDSA/ATS criteria.

Survival benefit associated with clarithromycin in severe community-acquired pneumonia: A matched comparator study

Although analysis of retrospective studies has documented survival benefit from the addition of a macrolide to the treatment regimen for community-acquired pneumonia (CAP), no data are available to determine if there is differential efficacy between members of the macrolide family. In order to investigate this, an analysis was undertaken of data from 1174 patients with CAP who met the new Sepsis-3 definitions and were enrolled prospectively in the data registry of the Hellenic Sepsis Study Group. Four well-matched treatment groups were identified with 130 patients per group: clarithromycin and β-lactam; azithromycin and β-lactam; respiratory fluoroquinolone and β-lactam monotherapy. The primary endpoint was comparison of the effects of clarithromycin with β-lactam monotherapy on 28-day mortality. The secondary endpoint was resolution of CAP. Mortality rates for the clarithromycin, azithromycin, respiratory fluoroquinolone and β-lactam groups were 20.8%, 33.8% (P=0.026 vs clarithromycin), 32.3% (P=0.049 vs clarithromycin) and 36.2% (P=0.009 vs clarithromycin), respectively. After stepwise Cox regression analysis among all groups, clarithromycin was the only treatment modality associated with a favourable outcome (hazard ratio 0.61; P=0.021). CAP resolved in 73.1%, 65.9% (P=0.226 vs clarithromycin), 58.5% (P=0.009 vs clarithromycin) and 61.5% (P=0.046 vs clarithromycin) of patients, respectively. It is concluded that the addition of clarithromycin to the treatment regimen of patients with severe CAP leads to better survival rates.

Pharmacotherapy of Lower Respiratory Tract Infections in Elderly-Focused on Antibiotics

Lower respiratory tract infections (LRTIs) refer to the inflammation of the trachea, bronchi, bronchioles, and lung tissue. Old people have an increased risk of developing LRTIs compared to young adults. The prevalence of LRTIs in the elderly population is not only related to underlying diseases and aging itself, but also to a variety of clinical issues, such as history of hospitalization, previous antibacterial therapy, mechanical ventilation, antibiotic resistance. These factors mentioned above have led to an increase in the prevalence and mortality of LRTIs in the elderly, and new medical strategies targeting LRTIs in this population are urgently needed. After a systematic review of the current randomized controlled trials and related studies, we recommend novel pharmacotherapies that demonstrate advantages for the management of LRTIs in people over the age of 65. We also briefly reviewed current medications for respiratory communicable diseases in the elderly. Various sources of information were used to ensure all relevant studies were included. We searched Pubmed, MEDLINE (OvidSP), EMBASE (OvidSP), and ClinicalTrials.gov. Strengths and limitations of these drugs were evaluated based on whether they have novelty of mechanism, favorable pharmacokinetic/pharmacodynamic profiles, avoidance of interactions and intolerance, simplicity of dosing, and their ability to cope with challenges which was mainly evaluated by the primary and secondary endpoints. The purpose of this review is to recommend the most promising antibiotics for treatment of LRTIs in the elderly (both in hospital and in the outpatient setting) based on the existing results of clinical studies with the novel antibiotics, and to briefly review current medications for respiratory communicable diseases in the elderly, aiming to a better management of LRTIs in clinical practice.

Severe community-acquired pneumonia in general medical wards: outcomes and impact of initial antibiotic selection

Background

Most international guidelines recommend empirical therapy for community-acquired pneumonia (CAP) to be based on site of care. Some patients with severe CAP are managed in general wards because of limited intensive care unit (ICU) bed or because of unrecognition of the pneumonia severity. Appropriate initial antibiotic treatment for severe CAP outside ICU has not yet been established. This study aimed to determine the prevalence and the impact of initial antibiotic selection on the outcomes of patients with severe CAP who were admitted and managing in general wards.

Methods

This prospective observational study included consecutive patients hospitalized for presumed CAP in general wards over a 1-year period. Severe CAP was identified using the 2007 Infectious Diseases Society of America (IDSA)/American Thoracic Society (ATS) criteria. Initial antibiotic treatment in the first 24 h were collected. The primary outcome was the rate of unfavorable outcome (composite outcome of treatment failure and in-hospital death). The secondary outcome was the number of hospital-free days assessed 30 days after enrollment into the study.

Results

There were 94 patients hospitalized with CAP of which 50 (53.2%) patients were compatible with severe CAP. An etiologic diagnosis was found in 43 (45.8%) patients. The most common pathogens identified in patients with severe CAP were Staphylococcus aureus (28.6%) and Klebsiella pneumoniae (28.6%), followed by Pseudomonas aeruginosa (17.9%). Patients with severe CAP had significantly more positive blood culture than patients with non-severe CAP (24% VS 4.5%; p = .008). Initial antibiotic treatment were discordant with the IDSA/ATS guidelines in 42% of all patients hospitalized with CAP, and 52% of patients with severe CAP. Multivariate analysis revealed that age (OR 1.1, 95% CI 1.01–1.1) and initial antibiotic treatment discordant to guidelines for severe CAP in ICU (OR 4.6, 95% CI 1.3–17.1) were independent risk factors of the unfavorable outcome of patients with severe CAP. Patients with unfavorable outcome had lower number of hospital-free days than patients with favorable outcome (5.2 ± 8 days VS 18 ± 7.1 days; p < .001).

Conclusions

Patients with severe CAP outside ICU should be recognized for appropriate initial antibiotic selection to improve outcomes.

Efficacy of Azithromycin in a Mouse Pneumonia Model against Hospital-Acquired Methicillin-Resistant Staphylococcus aureus

The use of macrolides against pneumonia has been reported to improve survival; however, little is known about their efficacy against methicillin-resistant Staphylococcus aureus (MRSA) pneumonia. In this study, we investigated the effect of azithromycin (AZM) and compared it with that of vancomycin (VCM) and daptomycin (DAP) in a murine model of MRSA pneumonia. Mice were infected with MRSA by intratracheal injection and then treated with AZM, VCM, or DAP. The therapeutic effect of AZM, in combination or not with the other drugs, was compared in vivo, whereas the effect of AZM on MRSA growth and toxin mRNA expression was evaluated in vitro. In vivo, the AZM-treated group showed significantly longer survival and fewer bacteria in the lungs 24 h after infection than the untreated group, as well as the other anti-MRSA drug groups. No significant decrease in cytokine levels (interleukin-6 [IL-6] and macrophage inflammatory protein-2 [MIP-2]) in bronchoalveolar lavage fluid or toxin expression levels (α-hemolysin [Hla] and staphylococcal protein A [Spa]) was observed following AZM treatment. In vitro, AZM suppressed the growth of MRSA in late log phase but not in stationary phase. No suppressive effect against toxin production was observed following AZM treatment in vitro In conclusion, contrary to the situation in vitro, AZM was effective against MRSA growth in vivo in our pneumonia model, substantially improving survival. The suppressive effect on MRSA growth at the initial stage of pneumonia could underlie the potential mechanism of AZM action against MRSA pneumonia.

Guidelines to Manage Community-Acquired Pneumonia

Few guidelines have greater acceptance than that for management of community-acquired pneumonia (CAP). Despite this, areas remain controversial, and new challenges continue to emerge. Current guidelines differ from those of northern European countries predominantly in need for macrolide combination with β-lactams for hospitalized, non-intensive care unit patients. A preponderance of evidence favors combination therapy. Challenges for current and future CAP guidelines include new antibiotic classes, emergence of viruses as major causes for CAP, new diagnostic modalities, alternative risk stratification for pathogens resistant to usual CAP antibiotics, and evidence-based management of severe CAP, including immunomodulatory therapy such as corticosteroids.

Recommendations and guidelines for the treatment of pneumonia in Taiwan

Pneumonia is a leading cause of death worldwide, ranking third both globally and in Taiwan. This guideline was prepared by the 2017 Guidelines Recommendations for Evidence-based Antimicrobial agents use in Taiwan (GREAT) working group, formed under the auspices of the Infectious Diseases Society of Taiwan (IDST). A consensus meeting was held jointly by the IDST, Taiwan Society of Pulmonary and Critical Care Medicine (TSPCCM), the Medical Foundation in Memory of Dr. Deh-Lin Cheng, the Foundation of Professor Wei-Chuan Hsieh for Infectious Diseases Research and Education and CY Lee's Research Foundation for Pediatric Infectious Diseases and Vaccines. The final guideline was endorsed by the IDST and TSPCCM. The major differences between this guideline and the 2007 version include the following: the use of GRADE methodology for the evaluation of available evidence whenever applicable, the specific inclusion of healthcare-associated pneumonia as a category due to the unique medical system in Taiwan and inclusion of recommendations for treatment of pediatric pneumonia. This guideline includes the epidemiology and recommendations of antimicrobial treatment of community-acquired pneumonia, hospital-acquired pneumonia, ventilator-associated pneumonia, healthcare-associated pneumonia in adults and pediatric pneumonia.

Effect of Combined β-Lactam/Macrolide Therapy on Mortality According to the Microbial Etiology and Inflammatory Status of Patients With Community-Acquired Pneumonia

BACKGROUND

Antibiotic combinations that include macrolides have shown lower mortality rates than β-lactams in monotherapy or combined with fluoroquinolones in patients with community-acquired pneumonia (CAP). However, this effect has not been studied according to the levels of C-reactive protein in CAP with identified microbial cause. In patients with CAP and known microbial cause we aimed to evaluate 30-day mortality of a β-lactam plus macrolide (BL + M) compared with a fluoroquinolone alone or with a β-lactam (FQ ± BL).

METHODS

We analyzed a prospective observational cohort of patients with CAP admitted to the Hospital Clinic of Barcelona between 1996 and 2016. We included only patients with known microbial cause.

RESULTS

Of 1,715 patients (29%) with known etiology, a total of 932 patients (54%) received BL + M. Despite lower crude mortality in the BL + M group in the overall population (BL + M, 5% vs FQ ± BL, 8%; P = .015), after adjustment by a propensity score and baseline characteristics, the combination of BL + M had a protective effect on mortality only in patients with high inflammatory response (C-reactive protein, > 15 mg/dL) and pneumococcal CAP (adjusted OR, 0.28; 95% CI, 0.09-0.93). No benefits on mortality were observed for the population without high inflammatory response and pneumococcal CAP or with other etiologies.

CONCLUSIONS

The combination of a β-lactam with a macrolide was associated with decreased mortality in patients with pneumococcal CAP and in patients with high systemic inflammatory response. When both factors occurred together, BL + M was protective for mortality in the multivariate analysis.

Synthesis and evaluation of biological activity for dual-acting antibiotics on the basis of azithromycin and glycopeptides

One of the promising directions of the combined approach is the design of dual-acting antibiotics - heterodimeric structures on the basis of antimicrobial agents of different classes. In this study a novel series of azithromycin-glycopeptide conjugates were designed and synthesized. The structures of the obtained compounds were confirmed using NMR spectroscopy and mass spectrometry data including MS/MS analysis. All novel hybrid antibiotics were found to be either as active as azithromycin and vancomycin against Gram-positive bacterial strains or have superior activity in comparison with their parent antibiotics. One compound, eremomycin-azithromycin conjugate 16, demonstrated moderate activity against Enterococcus faecium and Enterococcus faecalis strains resistant to vancomycin, and equal to vancomycin's activity for the treatment of mice with Staphylococcus aureus sepsis.

Macrolide therapy is associated with lower mortality in community-acquired bacteraemic pneumonia

BACKGROUND

Community-acquired pneumonia (CAP) has a potential complication of bacteremia. The objective of this study was to define the clinical outcomes of patients with CAP and bacteremia treated with and without a macrolide.

MATERIALS AND METHODS

Secondary analysis of the Community-Acquired Pneumonia Organization database of hospitalized patients with CAP. Patients with a positive blood culture were categorized based on the presence or absence of a macrolide in their initial antimicrobial regimen, and severity of their CAP. Outcomes included in-hospital all-cause mortality, 30-day mortality, length of stay, and time to clinical stability.

RESULTS

Among 549 patients with CAP and bacteremia, 247 (45%) were treated with a macrolide and 302 (55%) were not. The primary pathogen was Streptococcus pneumoniae (74%). Poisson regression with robust error variance models were used to compare the adjusted effects of each study group on the outcomes. The unadjusted 30-day mortality was 18.4% in the macrolide group, and 29.6% in the non-macrolide group (adjusted relative risk (aRR)0.81; 95% confidence interval (CI)0.50-1.33; P = 0.41). Unadjusted in-hospital all-cause mortality was 7.3% in the macrolide group, and 18.9% in the non-macrolide group (aRR 0.54, 95% CI 0.30-0.98; P = 0.043). Length of stay and time to clinical stability were not significantly different.

CONCLUSIONS

In-hospital mortality, but not 30-day mortality, was significantly better in the macrolide group. Our data support the use of a macrolide in hospitalized patients with CAP and bacteraemia.

Guideline for Antibiotic Use in Adults with Community-acquired Pneumonia

Community-acquired pneumonia is common and important infectious disease in adults. This work represents an update to 2009 treatment guideline for community-acquired pneumonia in Korea. The present clinical practice guideline provides revised recommendations on the appropriate diagnosis, treatment, and prevention of community-acquired pneumonia in adults aged 19 years or older, taking into account the current situation regarding community-acquired pneumonia in Korea. This guideline may help reduce the difference in the level of treatment between medical institutions and medical staff, and enable efficient treatment. It may also reduce antibiotic resistance by preventing antibiotic misuse against acute lower respiratory tract infection in Korea.

Treatment and prevention of invasive pneumococcal disease

Invasive pneumococcal disease is a severe infection that mainly affects patients with associated comorbidity. The paediatric conjugate vaccination has resulted in a change in the adult vaccination strategy. The antibiotic resistance of pneumococcus is not currently a severe problem. Nevertheless, the World Health Organisation has included pneumococcus among the bacteria whose treatment requires the introduction of new drugs, such as ceftaroline and ceftobiprole. Although the scientific evidence is still limited, the combination of beta-lactams and macrolides is recommended as empiric therapy for bacteraemic pneumococcal pneumonia.

Effectiveness of combination therapy versus monotherapy with a third-generation cephalosporin in bacteraemic pneumococcal pneumonia: A propensity score analysis

OBJECTIVE

Combining a macrolide or a fluoroquinolone to beta-lactam regimens in the treatment of patients with moderate to severe community-acquired pneumonia is recommended by the international guidelines. However, the information in patients with bacteraemic pneumococcal pneumonia is limited.

METHODS

A propensity score technique was used to analyze prospectively collected data from all patients with bacteraemic pneumococcal pneumonia admitted from 2000 to 2015 in our institution, who had received empirical treatment with third-generation cephalosporin in monotherapy or plus macrolide or fluoroquinolone.

RESULTS

We included 69 patients in the monotherapy group and 314 in the combination group. After adjustment by PS for receiving monotherapy, 30-day mortality (OR 2.89; 95% CI 1.07-7.84) was significantly higher in monotherapy group. A higher 30-day mortality was observed in monotherapy group in both 1:1 and 1:2 matched samples although it was statistically significant only in 1:2 sample (OR: 3.50 (95% CI 1.03-11.96), P = 0.046).

CONCLUSIONS

Our study suggests that in bacteraemic pneumococcal pneumonia, empirical therapy with a third-generation cephalosporin plus a macrolide or a fluoroquinolone is associated with a lower mortality rate than beta-lactams in monotherapy. These results support the recommendation of combination therapy in patients requiring admission with moderate to severe disease.

A model for predicting bacteremia in patients with community-acquired pneumococcal pneumonia: a retrospective observational study

Background

Pneumococcal pneumonia causes high morbidity and mortality among adults. This study aimed to identify risk factors for bacteremic pneumococcal pneumonia, and to construct a prediction model for the development of bacteremia in patients with community-acquired pneumococcal pneumonia.

Methods

We retrospectively analyzed data from patients hospitalized with community-acquired pneumococcal pneumonia between April 2007 and August 2015. Logistic regression models were applied to detect risk factors for pneumococcal bacteremia, and a receiver operating characteristic curve was used to devise a prediction model.

Results

Based on the results of sputum cultures, urine antigen tests, and/or blood cultures, 389 patients were diagnosed with pneumococcal pneumonia, 46 of whom had bacteremia. In the multivariate analysis, age < 65 years, serum albumin level < 3.0 g/dL, need for intensive respiratory or vasopressor support (IRVS), and C-reactive protein level > 20 mg/dL were identified as independent risk factors for the development of pneumococcal bacteremia. The bacteremia prediction score based on receiver operating characteristic curve analysis had a sensitivity of 0.74 and a specificity of 0.78 in patients with two risk factors. The area under the receiver operating characteristic curve was 0.77 (95% confidence interval (CI), 0.70–0.85).

Conclusions

Age < 65 years, hypoalbuminemia, IRVS, and high C-reactive protein level on admission are independent risk factors for the development of bacteremia in patients with community-acquired pneumococcal pneumonia. A prediction model based on these four risk factors could help to identify patients with community-acquired pneumococcal pneumonia at high risk of developing bacteremia; this can be used to guide antibiotic choices.

Trial registration

UMIN-CTR UMIN 000004353. Registered 7 October 2010. Retrospectively registered.

The dilemma of monotherapy or combination therapy in community-acquired pneumonia

SCOPE

To study the factors associated with mortality in hospitalized patients with community-acquired pneumonia treated with monotherapy or combination therapy.

METHODS

PubMed and Scopus were searched. Patients receiving macrolides, β-lactams and fluoroquinolones, as monotherapy or in combination, were included. Meta-analyses and meta-regressions were performed.

RESULTS

Fifty studies were included. Overall, monotherapy was not associated with higher mortality than combination (RR 1.14, 95% CI 0.99-1.32, I² 84%). Monotherapy was associated with higher mortality than combination in North American and retrospective studies. β-lactam monotherapy was associated with higher mortality than β-lactam/macrolide combination in the primary (1.32, 1.12-1.56, I² 85%) and most sensitivity analyses. There was no difference in mortality between fluoroquinolone monotherapy and β-lactam/macrolide combination (0.98, 0.78-1.23, I² 73%). In meta-regressions, the moderators that could partially explain the observed statistical heterogeneity were the frequency of cancer patients (P = .03) and Pneumonia Severity Index score IV (P = .008).

CONCLUSION

Due to the considerable heterogeneity and inclusion of unadjusted data, it is difficult to recommend a specific antibiotic regimen over another. Specific antibiotic regimens, study design and the characteristics of the population under study seem to influence the reported outcomes.

Impact of antibiotic therapy in severe community-acquired pneumonia: Data from the Infauci study

Antibiotic therapy (AT) is the cornerstone of the management of severe community-acquired pneumonia (CAP). However, the best treatment strategy is far from being established. To evaluate the impact of different aspects of AT on the outcome of critically ill patients with CAP, we performed a post hoc analysis of all CAP patients enrolled in a prospective, observational, multicentre study. Of the 502 patients included, 76% received combination therapy, mainly a β-lactam with a macrolide (80%). AT was inappropriate in 16% of all microbiologically documented CAP (n=177). Hospital and 6months mortality were 34% and 35%. In adjusted multivariate logistic regression analysis, combination AT with a macrolide was independently associated with a reduction in hospital (OR 0.17, 95%CI 0.06-0.51) and 6months (OR 0.21, 95%CI 0.07-0.57) mortality. Prolonged AT (>7days) was associated with a longer ICU (14 vs. 7days; p<0.001) and hospital length of stay (LOS) (25 vs. 17days; p<0.001). Combination AT with a macrolide may be the most suitable AT strategy to improve both short and long term outcome of severe CAP patients. AT >7days had no survival benefit and was associated with a longer LOS.

Combination therapy with ampicillin and azithromycin improved outcomes in a mouse model of group B streptococcal sepsis

BACKGROUND

Evidence suggests that β-lactam monotherapy of streptococcal infections may incite stronger inflammation and is inferior to combination therapy with macrolides. We hypothesized that use of macrolides alone or in combination with a β-lactam for group B streptococcal (GBS) sepsis would improve outcomes by reducing inflammation.

METHODS

TNF-α was measured from supernatants of RAW 264.7 cells stimulated with GBS isolates, in presence of four treatment regimens: ampicillin alone, azithromycin alone, or combination of azithromycin plus ampicillin. Mouse model of GBS sepsis was developed and treated with same four regimens. Clinical sepsis scores were monitored; serum cytokines (TNF-α, IL-6, IL-10) and chemokines (MIP-1α) were measured at the end.

RESULTS

GBS isolates exposed to azithromycin or combination (compared to ampicillin alone) stimulated less TNF production in vitro. In the murine sepsis model, mortality was lower along with decreased sepsis scores in mice treated with combination therapy. Mean serum IL-6 was lower in mice treated with azithromycin alone (66±52 pg/ml) or combination of ampicillin plus azithromycin (52±22 pg/ml) compared to ampicillin alone (260±160 pg/ml) (p<0.005).

CONCLUSIONS

Combination therapy of ampicillin+azithromycin improved outcomes in a murine GBS sepsis model; this therapeutic approach deserves additional study.

The order of administration of macrolides and beta-lactams may impact the outcomes of hospitalized patients with community-acquired pneumonia: results from the community-acquired pneumonia organization

BACKGROUND

The beneficial effect of macrolides for the treatment of community-acquired pneumonia (CAP) in combination with beta-lactams may be due to their anti-inflammatory activity. In patients with pneumococcal meningitis, the use of steroids improves outcomes only if they are administered before beta-lactams. The objective of this study was to compare outcomes in hospitalized patients with CAP when macrolides were administered before, simultaneously with, or after beta-lactams.

METHODS

Secondary data analysis of the Community-Acquired Pneumonia Organization (CAPO) International Cohort Study database. Study groups were defined based on the sequence of administration of macrolides and beta-lactams. The study outcomes were time to clinical stability (TCS), length of stay (LOS) and in-hospital mortality. Accelerated failure time models were used to evaluate the adjusted impact of sequential antibiotic administration and time-to-event outcomes, while a logistic regression model was used to evaluate their adjusted impact on mortality.

RESULTS

A total of 99 patients were included in the macrolide before group and 305 in the macrolide after group. Administration of a macrolide before a beta-lactam compared to after a beta-lactam reduced TCS (3 vs. 4 days, p = .011), LOS (6 vs. 7 days, p = .002) and mortality (3 vs. 7.2%, p = .228).

CONCLUSIONS

The administration of macrolides before beta-lactams was associated with a statistically significant decrease in TCS and LOS and a non-statistically significant decrease in mortality. The beneficial effect of macrolides in hospitalized patient with CAP may occur only if administered before beta-lactams.

Ceftriaxone versus ceftriaxone plus a macrolide for community-acquired pneumonia in hospitalized patients with HIV/AIDS: a randomized controlled trial

OBJECTIVES

To evaluate if treatment with ceftriaxone and a macrolide, improved patient outcome when compared with monotherapy with ceftriaxone, in hospitalized patients with human immunodeficiency virus/acquired immunodeficient syndrome (HIV/AIDS) with community-acquired pneumonia (CAP).

METHODS

Adult patients with HIV hospitalized due to suspected CAP were randomized to receive one of two regimens, ceftriaxone plus macrolide or ceftriaxone plus placebo, at a 1:1 proportion (Brazilian Clinical Trials Registry: RBR-8wtq2b). The primary outcome was in-hospital mortality and the secondary outcomes were mortality within 14 days, need for vasoactive drugs, need for mechanical ventilation, time to clinical stability and length of hospitalization.

RESULTS

A total of 227 patients were randomized, two were excluded after randomization; 225 patients were analysed (112 receiving ceftriaxone plus placebo and 113 receiving ceftriaxone plus macrolide). The frequency of the primary outcome, in-hospital mortality, was not statistically different between the regimens: 12/112 (11%) patients who received ceftriaxone plus placebo and 17/113 (15%) who received ceftriaxone plus macrolide died during hospitalization (hazard ratio 1.22, 95% CI 0.57-2.59). We did not find differences between the regimens for any of the secondary outcomes, including mortality within 14 days, which occurred in 5/112 (4%) patients with ceftriaxone plus placebo and in 12/113 (11%) patients with ceftriaxone plus macrolide (relative risk 2.38, 95% CI 0.87-6.53).

CONCLUSIONS

Among hospitalized patients with HIV/AIDS with CAP, treatment with ceftriaxone and a macrolide did not improve patient outcomes, when compared with ceftriaxone monotherapy.

Using cluster analysis of cytokines to identify patterns of inflammation in hospitalized patients with community-acquired pneumonia: a pilot study

INTRODUCTION

Patients with severe community-acquired pneumonia (CAP) are believed to have an exaggerated inflammatory response to bacterial infection. Therapies aiming to modulate the inflammatory response have been largely unsuccessful, perhaps reflecting that CAP is a heterogeneous disorder that cannot be modulated by a single anti-inflammatory approach. We hypothesize that the host inflammatory response to pneumonia may be characterized by distinct cytokine patterns, which can be harnessed for personalized therapies.

METHODS

Here, we use hierarchical cluster analysis of cytokines to examine if patterns of inflammatory response in 13 hospitalized patients with CAP can be defined. This was a secondary data analysis of the Community-Acquired Pneumonia Inflammatory Study Group (CAPISG) database. The following cytokines were measured in plasma and sputum on the day of admission: interleukin (IL)-1β, IL-1 receptor antagonist (IL-1ra), IL-6, CXCL8 (IL-8), IL-10, IL-12p40, IL-17, interferon (IFN)γ, tumor necrosis factor (TNF)α, and CXCL10 (IP-10). Hierarchical agglomerative clustering algorithms were used to evaluate clusters of patients within plasma and sputum cytokine determinations.

RESULTS

A total of thirteen patients were included in this pilot study. Cluster analysis identified distinct inflammatory response patterns of cytokines in the plasma, sputum, and the ratio of plasma to sputum.

CONCLUSIONS

Inflammatory response patterns in plasma and sputum can be identified in hospitalized patients with CAP. Characterization of the local and systemic inflammatory response may help to better discriminate patients for enrollment into clinical trials of immunomodulatory therapies.

Using cluster analysis of cytokines to identify patterns of inflammation in hospitalized patients with community-acquired pneumonia: a pilot study

INTRODUCTION

Patients with severe community-acquired pneumonia (CAP) are believed to have an exaggerated inflammatory response to bacterial infection. Therapies aiming to modulate the inflammatory response have been largely unsuccessful, perhaps reflecting that CAP is a heterogeneous disorder that cannot be modulated by a single anti-inflammatory approach. We hypothesize that the host inflammatory response to pneumonia may be characterized by distinct cytokine patterns, which can be harnessed for personalized therapies.

METHODS

Here, we use hierarchical cluster analysis of cytokines to examine if patterns of inflammatory response in 13 hospitalized patients with CAP can be defined. This was a secondary data analysis of the Community-Acquired Pneumonia Inflammatory Study Group (CAPISG) database. The following cytokines were measured in plasma and sputum on the day of admission: interleukin (IL)-1β, IL-1 receptor antagonist (IL-1ra), IL-6, CXCL8 (IL-8), IL-10, IL-12p40, IL-17, interferon (IFN)γ, tumor necrosis factor (TNF)α, and CXCL10 (IP-10). Hierarchical agglomerative clustering algorithms were used to evaluate clusters of patients within plasma and sputum cytokine determinations.

RESULTS

A total of thirteen patients were included in this pilot study. Cluster analysis identified distinct inflammatory response patterns of cytokines in the plasma, sputum, and the ratio of plasma to sputum.

CONCLUSIONS

Inflammatory response patterns in plasma and sputum can be identified in hospitalized patients with CAP. Characterization of the local and systemic inflammatory response may help to better discriminate patients for enrollment into clinical trials of immunomodulatory therapies.

Host-directed therapies for infectious diseases: current status, recent progress, and future prospects

Despite extensive global efforts in the fight against killer infectious diseases, they still cause one in four deaths worldwide and are important causes of long-term functional disability arising from tissue damage. The continuing epidemics of tuberculosis, HIV, malaria, and influenza, and the emergence of novel zoonotic pathogens represent major clinical management challenges worldwide. Newer approaches to improving treatment outcomes are needed to reduce the high morbidity and mortality caused by infectious diseases. Recent insights into pathogen–host interactions, pathogenesis, inflammatory pathways, and the host's innate and acquired immune responses are leading to identification and development of a wide range of host-directed therapies with different mechanisms of action. Host-directed therapeutic strategies are now becoming viable adjuncts to standard antimicrobial treatment. Host-directed therapies include commonly used drugs for non-communicable diseases with good safety profiles, immunomodulatory agents, biologics (eg monoclonal antibodies), nutritional products, and cellular therapy using the patient's own immune or bone marrow mesenchymal stromal cells. We discuss clinically relevant examples of progress in identifying host-directed therapies as adjunct treatment options for bacterial, viral, and parasitic infectious diseases.

Beta-lactam plus macrolides or beta-lactam alone for community-acquired pneumonia: A systematic review and meta-analysis

It is unclear whether in the treatment of community-acquired pneumonia (CAP) beta-lactam plus macrolide antibiotics lead to better survival than beta-lactam alone. We report a systematic review and meta-analysis. Trials and observational studies published in English were included, if they provided sufficient data on odds ratio for all-cause mortality for a beta-lactam plus macrolide regimen compared with beta-lactam alone. Two investigators independently searched for eligible articles. Of 514 articles screened, 14 were included: two open-label randomized controlled trials (RCTs) comprising 1975 patients, one non-RCT interventional study comprising 1011 patients and 11 observational studies comprising 33 332 patients. Random-model meta-analysis yielded an odds ratio for all-cause death for beta-lactam plus macrolide compared with beta-lactam alone of 0.80 (95% CI 0.69-0.92, P = 0.002) with substantial heterogeneity (I(2)  = 59%, P for heterogeneity = 0.002). Severity-based subgroup analysis and meta-regression revealed that adding macrolide had a favourable effect on mortality only for severe CAP. Of the two RCTs, one suggested that macrolide plus beta-lactam lead to better outcome compared with beta-lactam alone, while the other did not. Subgrouping based on study design, that is, RCT versus non-RCT, which was almost identical to subgrouping based on severity, revealed substantial inter-subgroup heterogeneity. Compared with beta-lactam alone, beta-lactam plus macrolide may decrease all-cause death only for severe CAP. However, this conclusion is tentative because this was based mainly on observational studies.

Therapeutic strategies in pneumonia: going beyond antibiotics

Dysregulation of the innate immune system drives lung injury and its systemic sequelae due to breakdown of vascular barrier function, harmful hyperinflammation and microcirculatory failure, which contribute to the unfavourable outcome of patients with severe pneumonia. A variety of promising therapeutic targets have been identified and numerous innovative therapeutic approaches demonstrated to improve lung injury in experimental preclinical studies. However, at present specific preventive or curative strategies for the treatment of lung failure in pneumonia in addition to antibiotics are still missing. The aim of this mini-review is to give a short overview of some, but not all, adjuvant therapeutic strategies for pneumonia and its most important complications, sepsis and acute respiratory distress syndrome, and briefly discuss future perspectives.

Predictive and prognostic factors in patients with blood-culture-positive community-acquired pneumococcal pneumonia

In patients with pneumococcal community-acquired pneumonia (CAP), the risk factors for bacteraemia and its impact on outcomes are not fully elucidated. We aimed to compare characteristics of patients with blood-culture-positive versus blood-culture-negative pneumococcal CAP, and to characterise bacteraemic serotypes.We describe a prospective, observational study on nonimmunocompromised patients with pneumococcal CAP, from 1996 to 2013. We define severe pneumonia according to American Thoracic Society/Infectious Diseases Society of America guidelines.Of a total of 917 patients with pneumococcal CAP, 362 had blood-culture-positive pneumococcal pneumonia (BCPPP; 39%). High C-reactive protein (CRP) (≥20 mg·dL(-1)) (odds ratio (OR) 2.36, 95% CI 1.45-3.85), pleural effusion (OR 2.03, 95% CI 1.13-3.65) and multilobar involvement (OR 1.69, 95% CI 1.02-2.79) were independently associated with bacteraemic CAP, while nursing home resident (OR 0.12, 95% CI 0.01-1.00) was found as a protective factor. Despite the clinical differences, BCPPP showed similar outcomes to blood-culture-negative pneumococcal pneumonia (BCNPP). 14% of the serotypes (period 2006-2013) causing bacteraemia are included in pneumococcal conjugate vaccine PVC7, 74% in pneumococcal conjugate vaccine PVC13 and 83% in pneumococcal polysaccharide vaccine PPSV23.Pleural effusion, a high level of CRP and multilobar involvement predicted an increased risk of BCPPP. Although BCPPP patients were more severely ill at admission, mortality was not significantly greater than in BCNPP patients.

Precision medicine for the treatment of severe pneumonia in intensive care

Despite advances in its management, community-acquired pneumonia (CAP) remains the most important cause of sepsis-related mortality and the reason for many ICU admissions. Severity assessment is the cornerstone of CAP patient management and the attempts to ensure the best site of care and therapy. Survival depends on a combination of host factors (genetic, age, comorbidities, defenses), pathogens (virulence, serotypes) and drugs. To reduce CAP mortality, early adequate antibiotic therapy is fundamental. The use of combination therapy with a macrolide seems to improve the clinical outcome in the subset of patients with high inflammation due to immunomodulation. Guidelines on antibiotic therapy have been associated with beneficial effects, and studies of newer adjunctive drugs have produced promising results. This paper discusses the current state of knowledge regarding of precision medicine and the treatment of severe CAP patients.