Emerging antibiotics for community-acquired pneumonia

Diterpene Coronarin Attenuates Lipopolysaccharide-Induced Acute Lung Injury in Both In Vivo and In Vitro Models

Acute lung injury (ALI) is a clinical condition occurs due to severe systemic inflammatory response for clinical stimulus like pneumonia, sepsis, trauma, aspiration, inhalation of toxic gases, and pancreatitis. Disruption of alveolar barriers, activation of macrophages, infiltration of neutrophils, and proinflammatory cytokines are the vital events occurs during ALI. The drugs which inhibit these inflammatory response can protect lungs from inflammatory insults. In this study, we examined the potency of phytochemical coronarin, a diterpene which have been proven to possess anti-inflammatory, antioxidant, antiangiogenic, and antitumor activities. Healthy BALB/c mice were induced to acute lung injury with intra-tracheal administration of LPS and then treated with 5 and 10 mg/kg concentration of coronarin. The wet/dry lung weight of mice were estimated to assess the induction of pulmonary edema. BALF fluid was analyzed for protein concentrations and immune cells count. Myeloperoxidase activity and levels of chemokines MCP-2 and MIP-2, iNOS, COX-2, and PGE-2 were quantified to assess the immunomodulatory effect of coronarin against LPS-induced ALI. The levels of proinflammatory cytokines was measured to examine the anti-inflammatory property of coronarin, and it was confirmed with histopathological analysis of the lung tissue. Murine RAW 264.7 cells were utilized for the in vitro analysis. Cell cytoxicity and cytoprotective property of coronarin was assessed with MTT assay in LPS-treated Murine RAW 264.7. The anti-inflammatory property of coronarin was further confirmed in in vitro condition by estimating the levels of pro-inflammatory cytokines in coronarin-treated and untreated LPS-induced cells. Overall, our in vivo and in vitro results confirm coronarin significantly inhibited the infiltration of neutrophils prevented immunodulatory activity and synthesis of proinflammatory cytokines and alleviated the acute lung injury induced by LPS. Coronarin is a potent anti-inflammatory drug which can be subjected to further research to be prescribed as drug for ALI.

New Guidelines for Severe Community-acquired Pneumonia

In 2023, the new European guidelines on severe community-acquired pneumonia, providing clinical practice recommendations for the management of this life-threatening infection, characterized by a high burden of mortality, morbidity, and costs for the society. This review article aims to summarize the principal evidence related to eight different questions covered in the guidelines, by also highlighting the future perspectives for research activity.

Antibiotic Strategies for Severe Community-Acquired Pneumonia

Despite advancements in health systems and intensive care unit (ICU) care, along with the introduction of novel antibiotics and microbiologic techniques, mortality rates in severe community-acquired pneumonia (sCAP) patients have not shown significant improvement. Delayed admission to the ICU is a major risk factor for higher mortality. Apart from choosing the appropriate site of care, prompt and appropriate antibiotic therapy significantly affects the prognosis of sCAP. Treatment regimens involving ceftaroline or ceftobiprole are currently considered the best options for managing patients with sCAP. Additionally, several other molecules, such as delafloxacin, lefamulin, and omadacycline, hold promise as therapeutic strategies for sCAP. This review aims to provide a comprehensive summary of the key challenges in managing adults with severe CAP, focusing on essential aspects related to antibiotic treatment and investigating potential strategies to enhance clinical outcomes in sCAP patients.

Novel pyridinium cationic pleuromutilin analogues overcoming bacterial multidrug resistance

A series of pyridinium cation-substituted pleuromutilin analogues were designed, synthesized and evaluated for their antibacterial activities in vitro and in vivo. Most derivatives showed potent antibacterial activities, especially e4 that displayed the highest antibacterial activity against multi-drug resistant bacteria and was subjected to time-kill kinetics, resistance studies, cytotoxicity and molecular docking assays. Molecular docking results, scanning electron microscopy and o-nitrophenyl-β-galactopyranoside tests showed that e4 not only inhibited bacterial protein synthesis but also disrupted bacterial cell walls. Compound e4 showed an ED₅₀ of 5.68 mg/kg against multi-drug resistant Staphylococcus aureus in infected mice model. In in vivo and in vitro toxicity tests, e4 showed low toxic effects with an LD₅₀ of 879 mg/kg to mice. These results suggest that compound e4 may be considered as a new therapeutic candidate for bacterial infections.

Combination effect of azithromycin with TCM preparation Xiyanping injection against Klebsiella pneumoniae infection in rats

BACKGROUND

Klebsiella pneumoniae is known as one of the most principal opportunistic human pathogens. Although antibiotics such as the first-line agent azithromycin (AZM) usually are efficient for the treatment of K. pneumonia-related infections, growing threat from antibiotic resistance has become a major challenge. Various preparations based on traditional Chinese medicine (TCM) clinical experience have been developed to help combat such a global public health threat, including Xiyanping injection (XYP) that is made from the natural product andrographolide with potent heat-clearing and toxin-resolving functions.

PURPOSE

The present study aimed to demonstrate the therapeutic potential, as well as the action of mechanism of AZM in combination with XYP against K. pneumonia infection in rats.

METHODS

Pneumonia model of K. pneumoniae infection in rats was established and subjected to various treatments. The lung histopathological lesions were evaluated. ELISA and Griess techniques were used to determine the level of crucial cytokines. The protein expressions of MAPKs and NF-κB pathways were analyzed by Western blotting.

RESULTS

The combination in vivo could significantly inhibit the proliferation of K. pneumoniae in lung, improve the pathological changes of lung and reduce inflammatory factors in lung homogenate and bronchoalveolar lavage fluid, mainly by inactivating MAPKs and NF-κB signaling pathways. Combination therapy caused one-fold increase in apparent distribution volume of AZM in rats after multiple dosing, along with a significant increase of AZM level in lungs but obvious decrease in livers.

CONCLUSION

The combination therapy of AZM and XYP showed increased antibacterial and anti-inflammatory properties, indicating that it might be used to treat K. pneumoniae infection.

Pneumonia Update for Emergency Clinicians

Purpose of Review

Many new concepts in diagnosis, management, and risk stratification of patients with pneumonia have been described recently. The COVID pandemic made importance of viruses as dangerous pathogens of pneumonia quite clear while several non-invasive measures for patients with respiratory failure gained a more wide-spread usage.

Recent Findings

Studies continue to examine feasibility of bedside ultrasound as a tool in accurate diagnosis of pneumonia in the emergency department, and several new antibiotics have been approved for treatment while others are in late-stage clinical trials. Additionally, the Infectious Diseases Society, American Thoracic Society, and their European counterparts published updated guidelines in recent years. For differences important to emergency medicine clinicians and new emphasis as compared to the prior guidelines, please see Table 1. Several new antibiotics have been approved recently but remain relatively unknown to emergency clinicians as their use is frequently restricted to infectious disease specialists.Table 1

Clinical Efficacy Protocol of Yinhuapinggan Granules: A Randomized, Double-Blind, Parallel, and Controlled Clinical Trial Program for the Intervention of Community-Acquired Drug-Resistant Bacterial Pneumonia as a Complementary Therapy

Background: Community-acquired bacterial pneumonia (CABP) is an important health care concern in the worldwide, and is associated with significant morbidity, mortality, and health care expenditure. Streptococcus pneumoniae is the most frequent causative pathogen of CABP. Common treatment for hospitalized patients with CABP is empiric antibiotic therapy using β-lactams in combination with macrolides, respiratory fluoroquinolones, or tetracyclines. However, overuse of antibiotics has led to an increased incidence of drug-resistant S. pneumoniae, exacerbating the development of community-acquired drug-resistant bacterial pneumonia (CDBP) and providing a challenge for physicians to choose empirical antimicrobial therapy. Methods: Traditional Chinese medicine (TCM) is widely used as a complementary treatment for CDBP. Yinhuapinggan granules (YHPG) is widely used in the adjuvant treatment of CDBP. Experimental studies and small sample clinical trials have shown that YHPG can effectively reduce the symptoms of CDBP. However, there is a lack of high-quality clinical evidence for the role of YHPG as a complementary drug in the treatment of CDBP. Here, we designed a randomized, double-blind, placebo-controlled clinical trial to explore the efficacy and safety of YHPG. A total of 240 participants will be randomly assigned to the YHPG or placebo group in a 1:1 ratio. YHPG and placebo will be added to standard treatment for 10 days, followed by 56 days of follow-up. The primary outcome is the cure rate of pneumonia, and the secondary outcomes includes conversion rate of severe pneumonia, lower respiratory tract bacterial clearance, lactic acid (LC) clearance rate, temperature, C-reactive protein (CRP), criticality score (SMART-COP score), acute physiological and chronic health assessment system (APACHEII score) and clinical endpoint events. Adverse events will be monitored throughout the trial. Data will be analyzed according to a pre-defined statistical analysis plan. This research will disclose the efficacy of YHPG in acquired drug-resistant pneumonia. Clinical Trial Registration: https://clinicaltrials.gov, identifier ChiCTR2100047501.

Antibiotic stewardship programmes had a low impact on prescribing for acute respiratory tract infections in children

Aim

This mini review summarises the available data on antibiotic stewardship programmes (ASP) for acute respiratory tract infections (ARTI) in paediatric outpatients, particularly the implementation and impact of programmes.

Methods

PubMed was searched from 1 January 2012 to 31 December 2021 for papers with abstracts that used the terms respiratory tract infection, antibiotic, child and guideline. We then saw how many of these included the individual terms impact, implementation or stewardship. After exclusions, we included 10 papers that were published in English on children treated as outpatients for ARTIs. All of these included data on implementing and assessing the impact of ASPs.

Results

The primary care data were mainly from the United States. The ASP programmes did not influence antibiotic prescription rates, but broad‐spectrum antibiotics decreased by 43–48%. The emergency department data were mainly from France and the antibiotic prescription rate decreased by 31–35% and the rate for broad‐spectrum antibiotics by 63–71%. A nationwide register‐based study from France confirmed these results.

Conclusion

ASPs had a low impact on overall antibiotic prescription rates and a modest impact on prescribing broad‐spectrum antibiotics. The implementation of ASP protocols needs further development, and more research is necessary on barriers to complying with ASPs.

Choosing antibiotic therapy for severe community-acquired pneumonia

PURPOSE OF REVIEW

Community-acquired pneumonia (CAP) is known as a major worldwide health concern considering it has been shown to account for 78% of infection-related deaths in the USA. It is a common cause for hospitalization with a continued incidence rise in the elderly, high mortality rate and long-term sequelae in critically ill patients. Severe CAP (sCAP) is an accepted terminology used to describe ICU admitted patients with CAP. The aim of this review is to further report on the major advances in treatment for patients with sCAP including new antibiotic treatments despite macrolide resistance as seen in the ICU, and multifaceted antibiotic stewardship interventions that may lead to the reduction broad-spectrum antibiotic use in CAP.

RECENT FINDINGS

We aim to examine the most recent findings in order to determine appropriate empirical antibiotic choices, timing regimens and evidence for clinical effectiveness. This will be addressed by focusing on the use combination therapies, the usefulness of severity scores and the difficulty to treat multidrug-resistant pathogens, including gram negatives such as Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus. Relevant reports referenced within included randomized controlled trials, meta-analyses, observational studies, systematic reviews and international guidelines where applicable.

SUMMARY

New antibiotics have been recently launched with direct agent-specific properties that have been shown to avoid the overuse of previous broad-spectrum antibiotics when treating patients sCAP. Although narrow-spectrum antibiotics are now recommended and imperative in improving a patients' prognosis, there are also some considerations when prescribing antibiotics that are beyond the spectrum. There is a need to implement effective policies of de-escalation to avoid antibiotic resistance and the risk for developing subsequent infections by combining informed clinical judgement and the application of biomarkers. Reaching clinical stability and avoidance of treatment failure are the most important pillars in treatment success.

Exploration of structural requirements for azole chemicals towards human aromatase CYP19A1 activity: Classification modeling, structure-activity relationships and read-across study

Human aromatase, also called CYP19A1, plays a major role in the conversion of androgens into estrogens. Inhibition of aromatase is an important target for estrogen receptor (ER)-responsive breast cancer therapy. Use of azole compounds as aromatase inhibitors is widespread despite their low selectivity. A toxicological evaluation of commonly used azole-based drugs and agrochemicals with respect to CYP19A1is currently requested by the European Union- Registration, Evaluation, Authorization and Restriction of Chemicals (EU-REACH) regulations due to their potential as endocrine disruptors. In this connection, identification of structural alerts (SAs) is an effective strategy for the toxicological assessment and safe drug design. The present study describes the identification of SAs of azole-based chemicals as guiding experts to predict the aromatase activity. Total 21 SAs associated with aromatase activity were extracted from dataset of 326 azole-based drugs/chemicals obtained from Tox21 library. A cross-validated classification model having high accuracy (error rate 5%) was proposed which can precisely classify azole chemicals into active/inactive toward aromatase. In addition, mechanistic details and toxicological properties (agonism/antagonism) of azoles with respect to aromatase were explored by comparing active and inactive chemicals using structure-activity relationships (SAR). Lastly, few structural alerts were applied to form chemical categories for read-across applications.

The remaining unsolved problems for rational antibiotic therapy use in pediatric community-acquired pneumonia

INTRODUCTION

Despite availability of several official guidelines, not all the problems related to the most effective and safe use of antibiotics in children with community-acquired pneumonia (CAP) have been solved. Presently, too many children receive unneeded antibiotics or, when antibiotics are mandatory, the choice of the drug is not appropriate.

AREAS COVERED

In this paper, the authors discuss the remaining unsolved problems for rational antibiotic therapy use in pediatric community-acquired pneumonia and provide their expert perspectives.

EXPERT OPINION

Further improvement in pediatric CAP management could be derived from physician education on antibiotic use and a larger use, particularly in office practice, of point of care testing or new technologies (i.e. artificial intelligence) to define etiology of a lower respiratory infection. However, recommendations regarding the duration of antibiotic therapy vary largely because of the absence of reliable data on the optimal CAP treatment according to the bacterial etiology of the disease, its severity, and child characteristics. Available evidence seems to confirm that a short course of antibiotics, approximately 5 days, can be effective and lead to results not substantially different from those obtained with prolonged-course antibiotic therapy, at least in patients with mild to moderate disease.

Delafloxacin for the treatment of adult patients with community-acquired bacterial pneumonia

INTRODUCTION

Delafloxacin is a novel fluoroquinolone with peculiar characteristics such as a weak acid character, frequent in vitro activity against methicillin-resistant Staphylococcus aureus (MRSA), and a low potential for resistance selection compared with other fluoroquinolones.

AREAS COVERED

The present narrative review summarizes the available data on the use of delafloxacin for the treatment of community-acquired bacterial pneumonia (CABP).

EXPERT OPINION

Delafloxacin is a novel fluoroquinolone with a unique profile and some interesting characteristics for the treatment of CABP, such as its marked activity against gram-positive bacteria, including MRSA, the possible use as monotherapy (owing to anti-Gram-negative and anti-atypical bacteria activity), the retained activity against many Gram-positive organisms resistant to other fluoroquinolones, and the availability of both oral and intravenous formulations. The results of the DEFINE-CABP phase-3 randomized controlled trial have shown noninferiority of delafloxacin vs. moxifloxacin for the treatment of CABP, thereby providing a further option for this indication. Against this background, future post-marketing experiences remain of crucial importance for further refining the place in therapy of delafloxacin in the real-life management algorithms of CABP, either as first-line option or step-down/outpatient treatment.

Antibiotic therapy in children with community-acquired pneumonia

PubMed was reviewed on antibiotic treatment of community-acquired pneumonia (CAP) in children for the years 2011-2020, and three clinical trials in high-income and eight in low-income countries were found. Prospective studies combining laboratory and clinical findings for steering of antibiotic treatment found that five-day courses were equally effective as longer courses. No new antibiotics were launched for children's CAP during the last 10 years. Five-day courses are equally effective as 7- to 10-day courses for CAP in children. Stewardship of antibiotics needs lessening of exposure to antibiotics by better targeting their use and by shortening the lengths of antibiotic courses.

The mechanism of nicotinamide on reducing acute lung injury by inhibiting MAPK and NF-κB signal pathway

Background

Acute lung injury is an important factor that leads to the death of patients with pneumonia. Previous studies have shown that nicotinamide (NAM) plays a role in reducing cell damage, so this study explored the mechanism by which NAM functions in acute lung injury.

Methods

We explored the mechanism by which NAM affects acute lung injury in vivo and in vitro by qRT-PCR, western blotting and ELISA.

Results

The results showed that NAM could significantly reduce lung injury and proinflammatory mediator accumulation. Further mechanistic studies showed that NAM could significantly inhibit the MAPK and AKT/NF-κB signaling pathways.

Conclusion

These results suggested that NAM may reduce the release of proinflammatory mediators by inhibiting the MAPK and AKT/NF-κB signaling pathways and ultimately alleviate lung injury.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10020-021-00376-2.

Community-acquired pneumonia

Community-acquired pneumonia is not usually considered a high-priority problem by the public, although it is responsible for substantial mortality, with a third of patients dying within 1 year after being discharged from hospital for pneumoniae. Although up to 18% of patients with community-acquired pneumonia who were hospitalised (admitted to hospital and treated there) have at least one risk factor for immunosuppression worldwide, strong evidence on community-acquired pneumonia management in this population is scarce. Several features of clinical management for community-acquired pneumonia should be addressed to reduce mortality, morbidity, and complications related to community-acquired pneumonia in patients who are immunocompetent and patients who are immunocompromised. These features include rapid diagnosis, microbiological investigation, prevention and management of complications (eg, respiratory failure, sepsis, and multiorgan failure), empirical antibiotic therapy in accordance with patient's risk factors and local microbiological epidemiology, individualised antibiotic therapy according to microbiological data, appropriate outcomes for therapeutic switch from parenteral to oral antibiotics, discharge planning, and long-term follow-up. This Seminar offers an updated view on community-acquired pneumonia in adults, with suggestions for clinical and translational research.

Community-acquired pneumonia: Trends in and research on drug resistance and advances in new antibiotics

Community-acquired pneumonia (CAP) refers to infectious inflammation of the lung parenchyma developing outside of a hospital. CAP has quite a high mortality and morbidity rate worldwide, and especially among elderly patients. The increasing burden of CAP is due to antibiotic resistance, the growth of the elderly population, and underlying comorbidities. Streptococcus pneumoniae remains the most common bacterial pathogen causing CAP, but multi-drug resistance bacteria and potential pathogens have increased the difficulty and challenges of managing CAP. Although preventive measures, diagnostic techniques, and treatment strategies are constantly advancing and improving, the susceptibility of multi-drug resistant pathogens, such as including Methicillin-Resistant Staphylococcus aureus (MRSA), Klebsiella pneumoniae, and Pseudomonas aeruginosa, has not improved significantly in recent decades, thus highlighting the importance and necessity of developing new antibiotics for the treatment of CAP. New antimicrobials have been approved over the past few years that will expand treatment options for CAP, and especially for patients with potential comorbidities. This situation also offers the chance to reduce the abuse of antibiotics, their toxicities, and their adverse reactions and to provide effective personalized antibiotic treatment.

Dryocrassin ABBA ameliorates Streptococcus pneumoniae-induced infection in vitro through inhibiting Streptococcus pneumoniae growth and neutralizing pneumolysin activity

To explore the role of dryocrassin ABBA (ABBA) in the prevention and treatment of Streptococcus pneumoniae (S. pneumoniae) infections in vitro, a minimal inhibitory concentration test, growth curve assay, hemolysis assay, BacLight LIVE/DEAD staining experiments, oligomerization inhibition assay, time-killing test, LDH release detection assay and cytotoxicity test were performed to evaluate the efficacy of ABBA against S. pneumoniae infections in vitro. The results indicated that ABBA treatment exists bactericidal effect on S. pneumoniae at a concentration of less than 8 μg/ml. Furthermore, ABBA was effective at inhibiting the oligomerization of pneumolysin (PLY) from reducing its hemolytic activity. Meanwhile, ABBA could ameliorate cell injury by neutralizing the biological activity of PLY without cytotoxicity. In summary, ABBA was a leading compound against S. pneumoniae infections through bactericidal effect and neutralizing PLY activity.

Community-Acquired Bacterial Pneumonia-Changing Epidemiology, Resistance Patterns, and Newer Antibiotics: Spotlight on Delafloxacin

Community-acquired pneumonia (CAP) is a major cause of morbidity and mortality both in the USA and globally. As the burden of CAP continues to increase due to several factors, the advances in its diagnosis, prevention, and treatment have taken on even greater interest and importance. The majority of CAP patients are treated empirically, and selection of appropriate antibiotic treatment is increasingly difficult because the epidemiology of CAP is changing, in part due to antimicrobial resistance, and the causative CAP pathogens differ between countries and regions. There is also an increasing prevalence of chronic co-morbid diseases among CAP patients. Treatment of CAP has become challenging because of these factors along with the varying safety profiles and efficacy of well-established antibiotics, as well as limited new therapeutic options. Recently, however, new antibiotics have been approved, which will expand the treatment options for CAP, particularly in those patients with underlying complications. Recently approved delafloxacin, an anionic fluoroquinolone, has a unique structure and distinct chemical characteristics; it demonstrated non-inferiority to moxifloxacin in a phase III clinical trial, but was shown to be superior to moxifloxacin at early clinical response in CAP patients who also have chronic obstructive pulmonary disease (COPD) or asthma as a co-morbidity, and in CAP patients who may have severe illness. Delafloxacin could offer an additional therapy against resistant isolates and among these difficult-to-treat patients. This review summarizes the development, latest research, and safety profile of the new antibiotic delafloxacin, and its potential future role in the treatment of CAP.

New cephalosporins for the treatment of pneumonia in internal medicine wards

The burden of hospital admission for pneumonia in internal medicine wards may not be underestimated; otherwise, cases of pneumonia are a frequent indication for antimicrobial prescriptions. Community- and hospital-acquired pneumonia are characterized by high healthcare costs, morbidity and non-negligible rates of fatality. The overcoming prevalence of resistant gram-negative and positive bacteria (e.g., methicillin-resistant Staphylococcus aureus, penicillin and ceftriaxone-resistant Streptococcus pneumoniae, extended-spectrum β-lactamases and carbapenemases producing Enterobacteriaceae) has made the most of the first-line agents ineffective for treating lower respiratory tract infections. A broad-spectrum of activity, favourable pulmonary penetration, harmlessness and avoiding in some cases a combination therapy, characterise new cephalosporins such as ceftolozane/tazobactam, ceftobiprole, ceftazidime/avibactam and ceftaroline. We aimed to summarise the role and place in therapy of new cephalosporins in community- and hospital-acquired pneumonia within the setting of internal medicine wards. The "universal pneumonia antibiotic strategy" is no longer acceptable for treating lung infections. Antimicrobial therapy should be individualized considering local antimicrobial resistance and epidemiology, the stage of the illness and potential host factors predisposing to a high risk for specific pathogens.