Mechanisms of action and clinical application of macrolides as immunomodulatory medications. Clin Microbiol Rev. 2010;23:590-615. [PMID: 20610825 DOI: 10.1128/cmr.00078-09]

Breaking boundaries: the advancements in transdermal delivery of antibiotics

Transdermal drug delivery systems (TDDS) for antibiotics have seen significant advances in recent years that aimed to improve the efficacy and safety of these drugs. TDDS offer many advantages over other conventional delivery systems such as non-invasiveness, controlled-release pattern, avoidance of first-pass metabolism. The objective of this review is to provide an overview on the recent advances in the TDDS of different groups of antibiotics including β-lactams, tetracyclines, macrolides, and lincosamides, utilized for their effective delivery through the skin and to explore the challenges associated with this field. The majority of antibiotics do not have favorable properties for passive transdermal delivery. Thus, novel strategies have been employed to improve the delivery of antibiotics through the skin, such as the use of nanotechnology (nanoparticles, solid-lipid nanoparticles, nanoemulsions, vesicular carriers, and liposomes) or the physical enhancement techniques like microneedles and ultrasound. In conclusion, the transdermal delivery systems could be a promising method for delivering antibiotics that have the potential to improve patient outcomes and enhance the efficacy of drugs. Further research and development are still needed to explore the potential of delivering more antibiotic drugs by using various transdermal drug delivery approaches.

The associations among peptic ulcer disease, Helicobacter pylori infection, and abdominal aortic aneurysms: A nationwide population-based cohort study

BACKGROUND

There are overlapping risk factors and underlying molecular mechanisms for both peptic ulcer disease (PUD) and abdominal aortic aneurysm (AAA). Despite improvements in the early diagnosis and treatment of AAA, ruptured AAAs continue to cause a substantial number of deaths. Helicobacter pylori are Gram-negative, microaerophilic bacteria that are now recognized as the main cause of PUD. H. pylori infection (HPI) is associated with an increased risk of certain cardiovascular diseases. HPIs can be treated with at least two different antibiotics to prevent bacteria from developing resistance to one particular antibiotic.

METHODS

We conducted a population-based cohort study using the National Health Insurance Research Database to evaluate whether associations exist among PUD, HPI, and eradication therapy for HPI and AAA. The primary outcome of this study was the cumulative incidence of AAA among patients with or without PUD and HPI during the 14-year follow-up period.

RESULTS

Our analysis included 7003 patients with PUD/HPI, 7003 patients with only PUD, and another 7003 age-, sex-, and comorbidity-matched controls from the database. We found that patients with PUD/HPI had a significantly increased risk of AAA compared to those with PUD alone and matched controls. The patients who had PUD/HPI had a significantly higher cumulative risk of developing AAA than those with PUD and the comparison group (2.67 % vs. 1.41 % vs. 0.73 %, respectively, p < 0.001). Among those patients with PUD/HPI, patients who had eradication therapy had a lower incidence of AAA than those without eradication therapy (2.46 % vs. 3.88 %, p = 0.012).

CONCLUSIONS

We revealed an association among PUD, HPI, and AAA, even after adjusting for age, sex, comorbidities, and annual medical follow-up visits. Notably, we found that HPI eradication therapy reduced the incidence of AAA among patients with PUD.

Prevalence and Risk Factors for Antimicrobial Resistance of Mycoplasma genitalium Infections in a High-Risk Population

Background/Objectives:Mycoplasma genitalium (MG) infections and antibiotic resistance are increasing in prevalence while treatment options are limited. Limited data exist regarding MG resistance in Israel. Our aim was to study the prevalence of MG resistance in a sexually transmitted infection (STI) clinic in Israel. Methods: We performed a single-center retrospective study among patients attending an STI clinic during 2019-2020. MG isolates were tested to detect their resistance to azithromycin and fluoroquinolones (FQs) using commercial kits (Allplex™ MG & AziR Assay, Allplex™ MG & MoxiR Assay). We collected patient data regarding the risk factors for STIs and resistance. A multivariate logistic regression model was used to identify the risk factors for resistance. Results: Of the 142 patients who tested positive for MG, 50 (35.2%) and 22 (15.5%) had resistant mutations to azithromycin and FQ, respectively, and 13 (9.2%) showed resistance to both agents. In a multivariate logistic regression model, men who have sex with men (RR 7.01 95% CI 3.00-16.33) and past STIs (RR 2.33 95% CI 1.01-5.34) were independent risk factors for azithromycin resistance. Conclusions: We found a high prevalence of azithromycin resistance and, to a lesser degree, FQ resistance. These findings may help design the treatment guidelines and support routine resistance testing in high-risk populations.

Impact of long-term macrolide therapy on the evaluation indicator of outpatient oral antimicrobial use according to the AWaRe classification

The WHO recently proposed a new indicator for judging the appropriateness of antimicrobial selection according to the AWaRe classification. Although macrolides are often administered for long-term macrolide therapy, the impact of this therapy on the indicator remains unclear. This study examined the impact of this therapy on the indicator for outpatient oral antimicrobial use. Using the JMDC claims database, outpatients who were prescribed an oral antimicrobial at least once between January and December 2022 (n = 2.66 million) were included in the study. The ratio of patient numbers and antimicrobial usage (AMU) were calculated based on age group (<15, 15-64, and ≥65 years) and prescription days (1-15, 16-30, 31-60, 61-90, and ≥91 days), and AMU of each drug was corrected for defined daily doses and classified according to the AWaRe. Patients with chronic airway disease for whom macrolides were prescribed for 91 days and more were defined as long-term macrolide therapy. Macrolides accounted for more than 30 % of total oral AMU in all age groups. In the elderly, 11.2 % of patients were prescribed macrolides for 91 days or more, accounting for 66.4 % of macrolide use. With regard to diseases that were associated with macrolide prescriptions, the percentage of patients prescribed for chronic airway diseases increased as the number of days of prescription increased. These results suggest that the impact of long-term macrolide therapy should be considered when assessing the appropriateness of outpatient oral AMU according to the AWaRe classification.

An in-depth analysis of COVID-19 treatment: Present situation and prospects

Coronavirus disease 2019 (COVID-19) the most contagious infection caused by the unique type of coronavirus known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), produced a global pandemic that wreaked havoc on the health-care system, resulting in high morbidity and mortality. Several methods were implemented to tackle the virus, including the repurposing of existing medications and the development of vaccinations. The purpose of this article is to provide a complete summary of the current state and future possibilities for COVID-19 therapies. We describe the many treatment classes, such as antivirals, immunomodulators, and monoclonal antibodies, that have been repurposed or developed to treat COVID-19. We also looked at the clinical evidence for these treatments, including findings from observational studies and randomized-controlled clinical trials, and highlighted the problems and limitations of the available evidence. Furthermore, we reviewed existing clinical trials and prospective COVID-19 therapeutic options, such as novel medication candidates and combination therapies. Finally, we discussed the long-term consequences of COVID-19 and the importance of ongoing research into the development of viable treatments. This review will help physicians, researchers, and policymakers to understand the prevention and mitigation of COVID-19.

Clarithromycin attenuates airway epithelial-mesenchymal transition in ovalbumin-induced asthmatic mice through modulation of Kv1.3 channels and PI3K/Akt signaling

Airway epithelial-mesenchymal transition (EMT) is the important pathological feature of airway remodeling in asthma. While macrolides are not commonly used to treat asthma, they have been shown to have protective effects on the airways, in which mechanisms are not yet fully understood. This study aims to investigate the impact of clarithromycin on airway EMT in asthma and its potential mechanism. The results revealed an increase in Kv1.3 expression in the airways of ovalbumin (OVA)-induced asthmatic mice, with symptoms and pathological changes being alleviated after treatment with the Kv1.3 inhibitor 5-(4-phenoxybutoxy)psoralen (PAP-1). Clarithromycin was found to attenuate airway epithelial-mesenchymal transition through the inhibition of Kv1.3 and PI3K/Akt signaling. Further experiments in vitro confirmed that PAP-1 could mitigate EMT by modulating the PI3K/Akt signaling in airway epithelial cells undergoing transformation into mesenchymal cells. These findings confirmed that clarithromycin might have a certain protective effect on asthma-related airway remodeling and represent a promising treatment strategy.

A novel 12-membered ring non-antibiotic macrolide EM982 attenuates cytokine production by inhibiting IKKβ and IκBα phosphorylation

Antimicrobial resistance poses a serious threat to human health worldwide and its incidence continues to increase owing to the overuse of antibiotics and other factors. Macrolide antibiotics such as erythromycin (EM) have immunomodulatory effects in addition to their antibacterial activity. Long-term, low-dose administration of macrolides has shown clinical benefits in treating non-infectious inflammatory respiratory diseases. However, this practice may also increase the emergence of drug-resistant bacteria. In this study, we synthesized a series of EM derivatives, and screened them for two criteria: (i) lack of antibacterial activity and (ii) ability to suppress tumor necrosis factor-α (TNF-α) production in THP-1 cells stimulated with lipopolysaccharide. Among the 37 synthesized derivatives, we identified a novel 12-membered ring macrolide EM982 that lacked antibacterial activity against Staphylococcus aureus and suppressed the production of TNF-α and other cytokines. The effects of EM982 on Toll-like receptor 4 (TLR4) signaling were analyzed using a reporter assay and Western blotting. The reporter assay showed that EM982 suppressed the activation of transcription factors, NF-κB and/or activator protein 1 (AP-1), in HEK293 cells expressing human TLR4. Western blotting showed that EM982 inhibited the phosphorylation of both IκB kinase (IKK) β and IκBα, which function upstream of NF-κB, whereas it did not affect the phosphorylation of p38 mitogen-activated protein kinase, extracellular signal-regulated kinase, and c-Jun N-terminal kinase, which act upstream of AP-1. These results suggest that EM982 suppresses cytokine production by inhibiting phosphorylation of IKKβ and IκBα, resulting in the inactivation of NF-κB.

Azithromycin for Pediatric Critical Asthma: A Multicenter Retrospective Cohort Study

OBJECTIVES

To characterize the prescribing trends and clinical outcomes related to azithromycin (AZI) among children hospitalized for critical asthma (CA).

METHODS

We performed a multicenter, retrospective cohort study using the Pediatric Health Information Systems registry of children 3 to 17 years of age hospitalized in a PICU for CA from January 2011 to December 2022. We excluded for alternative indications for AZI (eg, atypical pneumonia, B. pertussis infection, acute otitis media, acute sinusitis, pharyngitis/tonsillitis, and urethritis). The primary outcome was AZI prescribing rate by hospital and calendar year (trends assessed by Joinpoint regression). Cohorts with and without AZI exposure were further characterized by demographics, CA treatments, and inpatient outcomes using descriptive and comparative (ie, χ2 and Wilcoxon rank tests) statistics.

RESULTS

Of the 47 797 children studied, 9901 (20.7%) were prescribed AZI with a downward annual trend noted from 34.7% in 2011% to 12.4% in 2022 (-1.7% per year, R2 = 0.91). Median institutional AZI prescribing rate was 19.2% (interquartile range [IQR] 11.7%-28%; total range 5.6%-60%). Compared with children not prescribed AZI, those prescribed AZI were older (median 8.3 [IQR 5.7-11.6] vs 7.3 [4.9-10.8] years, P < .001) and experienced a more severe clinical trajectory with greater rates of bilevel positive airway pressure ventilation (19.7% vs 12.6%, P < .001), invasive ventilation (22.1% vs 13.5%, P < .001), extracorporeal life support (0.8% vs 0.1%, P < .001), and median length of stay (4 [IQR 3-6] vs 3 [IQR 2-4] days, P < .001).

CONCLUSIONS

Between 2011 and 2022, 20.7% of children hospitalized for CA were prescribed AZI notwithstanding the absence of trial-derived efficacy or safety data for this indication and population.

Analyzing atomic scale structural details and nuclear spin dynamics of four macrolide antibiotics: erythromycin, clarithromycin, azithromycin, and roxithromycin

The current investigation centers on elucidating the intricate molecular architecture and dynamic behavior of four macrolide antibiotics, specifically erythromycin, clarithromycin, azithromycin, and roxithromycin, through the application of sophisticated solid-state nuclear magnetic resonance (SSNMR) methodologies. We have measured the principal components of chemical shift anisotropy (CSA) parameters, and the site-specific spin-lattice relaxation time at carbon nuclei sites. To extract the principal components of CSA parameters, we have employed 13C 2DPASS CP-MAS SSNMR experiments at two different values of magic angle spinning (MAS) frequencies, namely 2 kHz and 600 Hz. Additionally, the spatial correlation between 13C and 1H nuclei has been investigated using 1H-13C frequency switched Lee-Goldburg heteronuclear correlation (FSLGHETCOR) experiment at a MAS frequency of 24 kHz. Our findings demonstrate that the incorporation of diverse functional groups, such as the ketone group and oxime group with the lactone ring, exerts notable influences on the structure and dynamics of the macrolide antibiotic. In particular, we have observed a significant decrease in the spin-lattice relaxation time of carbon nuclei residing on the lactone ring, desosamine, and cladinose in roxithromycin, compared to erythromycin. Overall, our findings provide detailed insight into the relationship between the structure and dynamics of macrolide antibiotics, which is eventually correlated with their biological activity. This knowledge can be utilized to develop new and more effective drugs by providing a rational basis for drug discovery and design.

In Vivo Immune-Modulatory Activity of Lefamulin in an Influenza Virus A (H1N1) Infection Model in Mice

Lefamulin is a first-in-class systemic pleuromutilin antimicrobial and potent inhibitor of bacterial translation, and the most recent novel antimicrobial approved for the treatment of community-acquired pneumonia (CAP). It exhibits potent antibacterial activity against the most prevalent bacterial pathogens that cause typical and atypical pneumonia and other infectious diseases. Early studies indicate additional anti-inflammatory activity. In this study, we further investigated the immune-modulatory activity of lefamulin in the influenza A/H1N1 acute respiratory distress syndrome (ARDS) model in BALB/c mice. Comparators included azithromycin, an anti-inflammatory antimicrobial, and the antiviral oseltamivir. Lefamulin significantly decreased the total immune cell infiltration, specifically the neutrophils, inflammatory monocytes, CD4+ and CD8+ T-cells, NK cells, and B-cells into the lung by Day 6 at both doses tested compared to the untreated vehicle control group (placebo), whereas azithromycin and oseltamivir did not significantly affect the total immune cell counts at the tested dosing regimens. Bronchioalveolar lavage fluid concentrations of pro-inflammatory cytokines and chemokines including TNF-α, IL-6, IL-12p70, IL-17A, IFN-γ, and GM-CSF were significantly reduced, and MCP-1 concentrations were lowered (not significantly) by lefamulin at the clinically relevant 'low' dose on Day 3 when the viral load peaked. Similar effects were also observed for oseltamivir and azithromycin. Lefamulin also decreased the viral load (TCID50) by half a log10 by Day 6 and showed positive effects on the gross lung pathology and survival. Oseltamivir and lefamulin were efficacious in the suppression of the development of influenza-induced bronchi-interstitial pneumonia, whereas azithromycin did not show reduced pathology at the tested treatment regimen. The observed anti-inflammatory and immune-modulatory activity of lefamulin at the tested treatment regimens highlights a promising secondary pharmacological property of lefamulin. While these results require confirmation in a clinical trial, they indicate that lefamulin may provide an immune-modulatory activity beyond its proven potent antibacterial activity. This additional activity may benefit CAP patients and potentially prevent acute lung injury (ALI) and ARDS.

Augmentation of Therapeutic Efficacy of Extraction of Causative Teeth by Irrigation for Odontogenic Maxillary Sinusitis

BACKGROUND/AIM

Odontogenic maxillary sinusitis is a clinically popular disease, but radical surgery and endoscopic surgery are often required. In the present study, we compared for the first time the therapeutic efficacy of the extraction of causative teeth with or without irrigation of the extraction fossa.

PATIENTS AND METHODS

A total of 60 patients underwent extraction of causative tooth. Among them, 34 patients underwent irrigation, while other 26 patients did not. Based on computed tomography (CT) images, treatment efficacy was quantified by the percentage of the remaining maxillary sinus mucosal lesions. The extent of therapeutic efficacy was evaluated following five grades, based on the percentage of remaining lesions: Grade 1 (0%) (disappearance of lesions), Grade 2 (roughly 10%), Grade 3 (roughly 30%), Grade 4 (approximately 50%) and Grade 5 (100%) (no improvement of the lesions).

RESULTS

Irrigation significantly augmented the therapeutic efficacy of tooth extraction for maxillary sinus mucosal lesions (mean grade: decreasing from 3.27 to 1.35).

CONCLUSION

The combination of tooth extraction and irrigation may contribute to the reduction of the necessity of surgery for the maxillary sinuses.

Azithromycin for acute bronchiolitis and wheezing episodes in children - a systematic review with meta-analysis

BACKGROUND

The aim of this systematic review and meta-analysis was to analyse the efficacy of azithromycin in acute bronchiolitis and wheezing.

METHODS

PubMed, Scopus, and Web of Science databases were searched for randomized controlled trials comparing azithromycin to placebo in children <2 years of age. Main outcomes were progress of acute wheezing episode and recurrence of wheezing. We used random-effects model to calculate mean difference (MD) with 95% confidence interval (CI) or risk ratios (RR) with CI.

RESULTS

We screened 1604 abstracts and included 7 studies. Risk of bias was low in three and had some concerns in four studies. Need for intensive care unit treatment was assessed in four studies (446 children) and the risk difference was 0.0% (CI -2.0 to 2.0; low quality evidence). Hospitalization duration was -0.27 days shorter in the azithromycin group (MD-0.27, CI -0.47 to -0.07; three studies; moderate quality evidence). Azithromycin did not prevent recurrence of wheezing (RR 0.84, CI 0.45-1.56; three studies), hospital readmissions (RR 1.14, CI 0.82-1.60; four studies).

CONCLUSIONS

We found moderate quality evidence that azithromycin may reduce hospitalization duration. Low certainty evidence suggests that azithromycin does not reduce the need for intensive care unit treatment. Furthermore, azithromycin did not prevent wheezing recurrence.

IMPACT

Azithromycin may reduce hospitalization time in acute bronchiolitis and wheezing episodes among children aged less than two. Azithromycin administrated during the acute wheezing period, does not have preventive effect on wheezing recurrence. Azithromycin seemed to have similar adverse event profile than placebo. Future studies with clinically relevant outcomes, and sufficient sample sizes are needed, before implementing azithromycin into clinical use.

Chemoenzymatic synthesis of macrocyclic peptides and polyketides via thioesterase-catalyzed macrocyclization

Chemoenzymatic strategies that combine synthetic and enzymatic transformations offer efficient approaches to yield target molecules, which have been increasingly employed in the synthesis of bioactive natural products. In the biosynthesis of macrocyclic nonribosomal peptides, polyketides, and their hybrids, thioesterase (TE) domains play a significant role in late-stage macrocyclization. These domains can accept mimics of native substrates in vitro and exhibit potential for use in total synthesis. This review summarizes the recent advances of TE domains in the chemoenzymatic synthesis for these natural products that aim to address the common issues in classical synthetic approaches and increase synthetic efficiencies, which have the potential to facilitate further pharmaceutical research.

Marine Natural Products as Novel Treatments for Parasitic Diseases

Parasitic diseases including malaria, leishmaniasis, and trypanosomiasis have received significant attention due to their severe health implications, especially in developing countries. Marine natural products from a vast and diverse range of marine organisms such as sponges, corals, molluscs, and algae have been found to produce unique bioactive compounds that exhibit promising potent properties, including antiparasitic, anti-Plasmodial, anti-Leishmanial, and anti-Trypanosomal activities, providing hope for the development of effective treatments. Furthermore, various techniques and methodologies have been used to investigate the mechanisms of these antiparasitic compounds. Continued efforts in the discovery and development of marine natural products hold significant promise for the future of novel treatments against parasitic diseases.

Observational retrospective clinical study on clinical features of macrolide-resistant Mycoplasma pneumoniae pneumonia in Chinese pediatric cases

This study aimed to investigate differences in clinical characteristics and laboratory findings between children infected with Macrolide-Sensitive Mycoplasma pneumoniae (MSMP) and Macrolide-Resistant Mycoplasma pneumoniae (MRMP). Additionally, the research sought to identify laboratory markers for rapidly distinguishing refractory Mycoplasma pneumoniae pneumonia (RMPP) from ordinary Mycoplasma pneumoniae pneumonia (OMPP). In total, 265 Mycoplasma pneumoniae (MP) patients were included, with MRMP identified by specific point mutations in domain V of the 23S rRNA gene. A retrospective analysis compared the clinical courses and laboratory data, revealing that MRMP patients experienced prolonged febrile days (P = 0.004), elevated CRP levels (P < 0.001), and higher MP DNA loads than MSMP patients (P = 0.037). Based on clinical symptoms, MRMP was divided into RMPP (n = 56) and OMPP (n = 70), with RMPP demonstrating significantly increased IL-18, community-acquired respiratory distress syndrome (CARDS) toxins in nasopharyngeal aspirate, and serum CRP levels (P < 0.001; P = 0.006; P < 0.001). In conclusion, timely recognition of RMPP is crucial for enhancing prognosis. The identification of MRMP, coupled with proinflammatory cytokines such as IL-18, CARDS toxins, and CRP, emerges as promising markers with the potential to contribute significantly to diagnostic accuracy and prognosis assessment.

Effect of clarithromycin in a case of infantile bullous pemphigoid

Although rare, cases of infantile or childhood bullous pemphigoid are increasingly being reported in the literature. Treatment challenges, which are amplified in infancy, necessitate balancing efficacy and avoiding long-term risks. In this report, clarithromycin was successfully used to establish and maintain disease remission, offering insights into its immunomodulatory effects, making it a compelling steroid-sparing choice with a favorable side effect profile.

The clarithromycin-binding proteins NIPSNAP1 and 2 regulate cytokine production through mitochondrial quality control

The mechanism underlying the anti-inflammatory effect of macrolide antibiotics, such as clarithromycin (CAM), remains to be clarified. The CAM-binding proteins 4-nitrophenylphosphatase domain and non-neuronal synaptosomal associated protein 25 (SNAP25)-like protein homolog (NIPSNAP) 1 and 2 are involved in the immune response and mitochondrial homeostasis. However, the axis between CAM-NIPSNAP-mitochondria and Toll-like receptor (TLR) and their molecular mechanisms remain unknown. In this study, we sought to elucidate the relationship between mitochondrial homeostasis mediated by NIPSNAP1 and 2 and the immunomodulatory effect of CAM. NIPSNAP1 or 2 knockdown (KD) by RNA interference impaired TLR4-mediated interleukin-8 (IL-8) production. Similar impairment was observed upon treatment with mitochondrial function inhibitors. However, IL-8 secretion was not impaired in NIPSNAP1 and 2 individual knockout (KO) and double KO (DKO) cells. Moreover, the oxygen consumption rate (OCR) in mitochondria measured using a flex analyzer was significantly reduced in NIPSNAP1 or 2 KD cells, but not in DKO cells. CAM also dose-dependently reduced the OCR. These results indicate that CAM suppresses the IL-8 production via the mitochondrial quality control regulated by temporary functional inhibition of NIPSNAP1 and 2. Our findings provide new insight into the mechanisms underlying cytokine production, including the TLR-mitochondria axis, and the immunomodulatory effects of macrolides.

Overcoming Microbiome-Acquired Gemcitabine Resistance in Pancreatic Ductal Adenocarcinoma

Gastrointestinal cancers (GICs) are one of the most recurrent diseases in the world. Among all GICs, pancreatic cancer (PC) is one of the deadliest and continues to disrupt people's lives worldwide. The most frequent pancreatic cancer type is pancreatic ductal adenocarcinoma (PDAC), representing 90 to 95% of all pancreatic malignancies. PC is one of the cancers with the worst prognoses due to its non-specific symptoms that lead to a late diagnosis, but also due to the high resistance it develops to anticancer drugs. Gemcitabine is a standard treatment option for PDAC, however, resistance to this anticancer drug develops very fast. The microbiome was recently classified as a cancer hallmark and has emerged in several studies detailing how it promotes drug resistance. However, this area of study still has seen very little development, and more answers will help in developing personalized medicine. PC is one of the cancers with the highest mortality rates; therefore, it is crucial to explore how the microbiome may mold the response to reference drugs used in PDAC, such as gemcitabine. In this article, we provide a review of what has already been investigated regarding the impact that the microbiome has on the development of PDAC in terms of its effect on the gemcitabine pathway, which may influence the response to gemcitabine. Therapeutic advances in this type of GIC could bring innovative solutions and more effective therapeutic strategies for other types of GIC, such as colorectal cancer (CRC), due to its close relation with the microbiome.

Antibacterial and Anti-inflammatory Effects of Clarithromycin-Loaded Poly(l-Lactide) Membrane in Rabbit Postoperation Model of Chronic Rhinosinusitis

OBJECTIVE

Macrolide antibiotics are often used to prevent infection and inflammation after functional endoscopic sinus surgery for the treatment of chronic rhinosinusitis (CRS). The purpose of this study was to investigate the anti-inflammatory and antibacterial effects of the clarithromycin-loaded poly(-lactide) (CLA-PLLA) membrane and its mechanism.

STUDY DESIGN

Randomized controlled trial.

SETTING

Animal Experiment Center.

METHODS

We compared the difference between poly(l-lactide) (PLLA) and CLA-PLLA membranes by observing the morphology of fibrous scaffolds, measuring water contact angle, tensile strength, and drug release capacity, and evaluating the antimicrobial activity of CLA-PLLA. Twenty-four rabbits were divided into a PLLA group and a CLA-PLLA group after establishing CRS models. Another 5 normal rabbits comprised the control group. After 3 months, we placed the PLLA membrane in the nasal cavity of the PLLA group and the CLA-PLLA membrane in the CLA-PLLA group. Then, 14 days later, we evaluated the histological and ultrastructural changes in the sinus mucosa, protein, and messenger RNA (mRNA) levels of interleukin (IL)-4, IL-8, tumor necrosis factor-α, transforming growth factor-β1, α-smooth muscle actin, and type I collagen.

RESULTS

The CLA-PLLA membrane showed no significant difference in physical performance to the PLLA membrane, which continuously released 95% of the clarithromycin (CLA) for 2 months. The CLA-PLLA membrane had significant bacteriostatic properties that can improve the morphology of mucosal tissues, and inhibit protein and mRNA expression of inflammatory cytokines. In addition, CLA-PLLA also inhibited the expression of fibrosis-associated marker molecules.

CONCLUSION

The CLA-PLLA membrane released CLA slowly and continuously, providing antibacterial, anti-inflammatory, and antifibrotic effects in a rabbit model of postoperative CRS.

The Effectiveness and Safety of Long-Term Macrolide Therapy for COPD in Stable Status: A Systematic Review and Meta-Analysis

Background: Chronic obstructive pulmonary disease (COPD) is a prevalent condition with fewer treatments available as the severity increases. Previous systematic reviews have demonstrated the benefits of long-term macrolide use. However, the therapeutic differences between different macrolides and the optimal duration of use remain unclear. Methods: A systematic review and meta-analysis were conducted to assess the effectiveness of long-term macrolide use in reducing COPD exacerbations, compare the therapeutic differences among macrolides, and determine the appropriate treatment duration. Four databases (PubMed, Cochrane Library, Web of Science, and ICHU-SHI) were searched until 20 March 2023, and a random-effects model was used to calculate the pooled effect. Results: The meta-analysis included nine randomized controlled trials involving 1965 patients. The analysis revealed an odds ratio (OR) of 0.34 (95% confidence interval [CI] 0.19, 0.59, p < 0.001) for the reduction in exacerbation frequency. Notably, only azithromycin or erythromycin showed suppression of COPD exacerbations. The ORs for reducing exacerbation frequency per year and preventing hospitalizations were -0.50 (95% CI: -0.81, -0.19; p = 0.001) and 0.60 (95% CI: 0.3, 0.97; p = 0.04), respectively. Statistical analyses showed no significant differences between three- and six-month macrolide prescriptions. However, studies involving a twelve-month prescription showed an OR of 0.27 (95% CI: 0.11, 0.68; p = 0.005; I2 = 81%). Although a significant improvement in St George's Respiratory Questionnaire (SGRQ) total scores was observed with a mean difference of -4.42 (95% CI: -9.0, 0.16; p = 0.06; I2 = 94%), the minimal clinically important difference was not reached. While no adverse effects were observed between the two groups, several studies have reported an increase in bacterial resistance. Conclusions: Long-term use of azithromycin or erythromycin suppresses COPD exacerbations, and previous studies have supported the advantages of a 12-month macrolide prescription over a placebo.

Inherent Fluorescence Demonstrates Immunotropic Properties for Novel Janus Kinase 3 Inhibitors

There is a general question in small molecule pharmacology about how apparent compound concentrations in blood, plasma, and organs actually relate to actual amounts at the target site of a compound. In this study, we used inherently fluorescent JAK3 ligands and their macrolide conjugates to investigate the relationship between physical properties, apparent bulk concentration, and organ and subcellular distribution. In vitro uptake into immune cells suggested that much of the substance was associated with granules or organelles. Samples from murine pharmacokinetic studies were analyzed by both conventional mass spectrometry and cryofluorescence microscopy methods to show the distribution of a compound within organs and cells without artifacts of fixation. These observations confirm the uptake of granules observed in vitro. Data from macrolides carrying either a coumarin fluorophore or a JAK3 inhibitor were similar, suggesting that the distribution is directed by the properties of the larger macrolide. These data show a propensity for azalide macrolides to concentrate in the lung and gut epithelia and suggest that the plasma- or whole-blood-derived estimates of drug levels almost certainly underestimate concentrations of macrolides in the mucous membranes. Thus, their apparent efficacy at sub-bacteriostatic doses may reflect their higher levels in barrier layers.

Azithromycin Mechanisms of Action in CRS Include Epithelial Barrier Restoration and Type 1 Inflammation Reduction

OBJECTIVE

Previous in vitro transcriptomic profiling suggests azithromycin exerts its effects in patients with chronic rhinosinusitis (CRS) via modulation of type 1 inflammation and restoration of epithelial barrier function. We wished to verify these postulated effects using in vitro models of epithelial repair and in vivo transcriptional profiling.

STUDY DESIGN

Functional effects of azithromycin in CRS were verified using in vitro models of wounding. The mechanism of the effect of azithromycin was assessed in vivo using transcriptomic profiling.

SETTING

Academic medical center.

METHODS

Effects of azithromycin on the speed of epithelial repair were verified in a wounding model using primary nasal epithelial cells (pNEC) from CRS patients. Nasal brushings collected pre-and posttreatment during a placebo-controlled trial of azithromycin for CRS patients unresponsive to surgery underwent transcriptomic profiling to identify implicated pathways.

RESULTS

Administration of azithromycin improved the wound healing rates in CRS pNECs and prevented the negative effect of Staphylococcus aureus on epithelial repair. In vivo, response to azithromycin was associated with downregulation in pathways of type 1 inflammation, and upregulation of pathways implicated in the restoration of the cell cycle.

CONCLUSION

Restoration of healthy epithelial function may represent a major mode of action of azithromycin in CRS. In vitro models show enhanced epithelial repair, while in vivo transcriptomics shows downregulation of pathways type 1 inflammation accompanied by upregulation of DNA repair and cell-cycle pathways. The maximal effect in patients with high levels of type 1-enhanced inflammation suggests that azithromycin may represent a novel therapeutic option for surgery-unresponsive CRS patients.

The Impact of Long-Term Macrolide Exposure on the Gut Microbiome and Its Implications for Metabolic Control

Long-term low-dose macrolide therapy is now widely used in the treatment of chronic respiratory diseases for its immune-modulating effects, although the antimicrobial properties of macrolides can also have collateral impacts on the gut microbiome. We investigated whether such treatment altered intestinal commensal microbiology and whether any such changes affected systemic immune and metabolic regulation. In healthy adults exposed to 4 weeks of low-dose erythromycin or azithromycin, as used clinically, we observed consistent shifts in gut microbiome composition, with a reduction in microbial capacity related to carbohydrate metabolism and short-chain fatty acid biosynthesis. These changes were accompanied by alterations in systemic biomarkers relating to immune (interleukin 5 [IL-5], IL-10, monocyte chemoattractant protein 1 [MCP-1]) and metabolic (serotonin [5-HT], C-peptide) homeostasis. Transplantation of erythromycin-exposed murine microbiota into germ-free mice demonstrated that changes in metabolic homeostasis and gastrointestinal motility, but not systemic immune regulation, resulted from changes in intestinal microbiology caused by macrolide treatment. Our findings highlight the potential for long-term low-dose macrolide therapy to influence host physiology via alteration of the gut microbiome. IMPORTANCE Long-term macrolide therapy is widely used in chronic respiratory diseases although its antibacterial activity can also affect the gut microbiota, a key regulator of host physiology. Macrolide-associated studies on the gut microbiota have been limited to short antibiotic courses and have not examined its consequences for host immune and metabolic regulation. This study revealed that long-term macrolides depleted keystone bacteria and impacted host regulation, mediated directly by macrolide activity or indirectly by alterations to the gut microbiota. Understanding these macrolide-associated mechanisms will contribute to identifying the risk of long-term exposure and highlights the importance of targeted therapy for maintenance of the gut microbiota.

Therapeutic efficacy of tylvalosin combined with Poria cocos polysaccharides against porcine reproductive and respiratory syndrome

Porcine reproductive and respiratory syndrome (PRRS) is one of the most economically important infectious diseases of pigs worldwide. Vaccination and various management measures have been implemented to control PRRS. However, due to high genetic diversity and insufficient understanding of the pathogenesis and immunological mechanisms, PRRS is still a challenge to the pig industry. Therefore, it is important to develop novel strategies to combat PRRS virus (PRRSV) infection. In this study, our data show that tylvalosin, a third-generation animal-specific macrolide, could inhibit PRRSV replication in MARC-145 cells, and suppress the PRRSV-induced NF-κB activation and cytokines expression. The pig infection experiment further demonstrated that tylvalosin could significantly reduce the virus loads in serum and tissues, and alleviate lung lesions of pigs infected with highly pathogenic PRRSV strains. The fever and loss of daily gain (LoDG) of the pigs were decreased as well. Considering the feature of immune suppression of PRRSV, a combination of tylvalosin with the immunopotentiator Poria cocos polysaccharides (PCP) was developed. Pig experiment showed this combination had a better therapeutic efficacy against PRRSV infection than tylvalosin and PCP alone in attenuating lung lesions, alleviating fever, and suppressing cytokines production. This study suggests that tylvalosin has significant antiviral and anti-inflammatory effects against PRRSV infection, and the combination of tylvalosin and PCP provides a promising strategy for PRRS treatment.

Selective Inhibitors of Janus Kinase 3 Modify Responses to Lipopolysaccharides by Increasing the Interleukin-10-to-Tumor Necrosis Factor α Ratio

Janus kinase (JAK) inhibitors act at low doses (e.g., tofacitinib, 0.2-0.4 μmol/kg bid) in clinical use, suggesting an efficient underlying mode of action. We hypothesized that their effectiveness is due to their ability to raise the ratio of IL-10 to TNFα. Unlike other JAK isoforms, JAK3 is expressed mainly in hematopoietic cells and is essential for immune function. We used JAK3 selective inhibitors with preferential distribution to immune cells. Inhibition of JAK3 in human leukocytes reduced TNFα and IL-6 but maintained levels of IL-10, while pan-JAK inhibitors increased TNFα, IL-6, and IL-10. JAK1 is required for IL-10 receptor signaling, which suggests that, at exposure above the IC50 (55 nM for tofacitinib on JAK1), there is less feedback control of TNFα levels. This leads to self-limiting effects of JAK1 inhibitors and could place an upper limit on appropriate doses. In vivo, treating mice with JAK3 inhibitors before LPS administration decreased plasma TNFα and increased IL-10 above vehicle levels, suggesting that JAK3 inhibition may limit TNFα release by increasing IL-10 while leaving the IL-10 receptor functional. This mechanism should have general utility in controlling autoimmune diseases and can be conveniently observed by measuring the ratio of IL-10 to TNFα. In summary, our targeted, "leukotropic" inhibitors more effectively increased IL-10/TNFα ratios than unselective control compounds and could, therefore, be ideal for autoimmune therapy.

The Mechanism of Action and Clinical Efficacy of Low-Dose Long-Term Macrolide Therapy in Chronic Rhinosinusitis

Various chronic inflammatory airway diseases can be treated with low-dose, long-term (LDLT) macrolide therapy. LDLT macrolides can be one of the therapeutic options for chronic rhinosinusitis (CRS) due to their immunomodulatory and anti-inflammatory actions. Currently, various immunomodulatory mechanisms of the LDLT macrolide treatment have been reported, as well as their antimicrobial properties. Several mechanisms have already been identified in CRS, including reduced cytokines such as interleukin (IL)-8, IL-6, IL-1β, tumor necrosis factor-α, transforming growth factor-β, inhibition of neutrophil recruitment, decreased mucus secretion, and increased mucociliary transport. Although some evidence of effectiveness for CRS has been published, the efficacy of this therapy has been inconsistent across clinical studies. LDLT macrolides are generally believed to act on the non-type 2 inflammatory endotype of CRS. However, the effectiveness of LDLT macrolide treatment in CRS is still controversial. Here, we reviewed the immunological mechanisms related to CRS in LDLT macrolide therapy and the treatment effects according to the clinical situation of CRS.

Impact of Administering Intravenous Azithromycin within 7 Days of Hospitalization for Influenza Virus Pneumonia: A Propensity Score Analysis Using a Nationwide Administrative Database

The potential antimicrobial and anti-inflammatory effectiveness of azithromycin against severe influenza is yet unclear. We retrospectively investigated the effect of intravenous azithromycin administration within 7 days of hospitalization in patients with influenza virus pneumonia and respiratory failure. Using Japan's national administrative database, we enrolled and classified 5066 patients with influenza virus pneumonia into severe, moderate, and mild groups based on their respiratory status within 7 days of hospitalization. The primary endpoints were total, 30-day, and 90-day mortality rates. The secondary endpoints were the duration of intensive-care unit management, invasive mechanical ventilation, and hospital stay. The inverse probability of the treatment weighting method with estimated propensity scores was used to minimize data collection bias. Use of intravenous azithromycin was proportional to the severity of respiratory failure (mild: 1.0%, moderate: 3.1%, severe: 14.8%). In the severe group, the 30-day mortality rate was significantly lower with azithromycin (26.49% vs. 36.65%, p = 0.038). In the moderate group, the mean duration of invasive mechanical ventilation after day 8 was shorter with azithromycin; there were no significant differences in other endpoints between the severe and moderate groups. These results suggest that intravenous azithromycin has favorable effects in patients with influenza virus pneumonia using mechanical ventilation or oxygen.

Should Airway Interstitial Fluid Be Used to Evaluate the Pharmacokinetics of Macrolide Antibiotics for Dose Regimen Determination in Respiratory Infection?

Macrolide antibiotics are important drugs to combat infections. The pharmacokinetics (PK) of these drugs are essential for the determination of their optimal dose regimens, which affect antimicrobial pharmacodynamics and treatment success. For most drugs, the measurement of their concentrations in plasma/serum is the surrogate for drug concentrations in target tissues for therapy. However, for macrolides, simple reliance on total or free drug concentrations in serum/plasma might be misleading. The macrolide antibiotic concentrations of serum/plasma, interstitial fluid (ISF), and target tissue itself usually yield very different PK results. In fact, the PK of a macrolide antibiotic based on serum/plasma concentrations alone is not an ideal predictor for the in vivo efficacy against respiratory pathogens. Instead, the PK based on drug concentrations at the site of infection or ISF provide much more clinically relevant information than serum/plasma concentrations. This review aims to summarize and compare/discuss the use of drug concentrations of serum/plasma, airway ISF, and tissues for computing the PK of macrolides. A better understanding of the PK of macrolide antibiotics based on airway ISF concentrations will help optimize the antibacterial dose regimen as well as minimizing toxicity and the emergence of drug resistance in clinical practice.

Prospects for macrolide therapy of asthma and COPD

Macrolide compounds, many of which are derived from natural sources, all share a lactone ring structure, but of varying sizes. Their biological activities differ with structure and size but tend to overlap. Marketed macrolide drugs include immunosuppressives and antibiotics. Some of the latter have been shown to exert anti-inflammatory activities, due to direct effects on inflammatory cells and processes when used for respiratory infections. Consequently, azithromycin is included in clinical guidelines for COPD and asthma treatment, though it has the disadvantage, as an antibiotic, of increasing bacterial resistance. COPD and asthma, however, like several chronic inflammatory diseases involving other organs, are driven to a large extent by epithelial barrier dysfunction. Recently, azithromycin was shown to directly enhance epithelial barrier function and a new class of derivatives, barriolides, is under development with the lead indication COPD. It is thus likely that by circumventing antibiosis and acting on a crucial etiological disease process, this type of agent will open up a new, safer approach to COPD and asthma therapy with macrolides.

Case Series of Patients with Coronavirus Disease 2019 Pneumonia Treated with Hydroxychloroquine

The efficacy of hydroxychloroquine (HCQ) therapy, a previous candidate drug for coronavirus disease 2019 (COVID-19), was denied in the global guideline. The risk of severe cardiac events associated with HCQ was inconsistent in previous reports. In the present case series, we show the tolerability of HCQ therapy in patients treated in our hospital, and discuss the advantages and disadvantages of HCQ therapy for patients with COVID-19. A representative case was a 66-year-old woman who had become infected with severe acute respiratory syndrome coronavirus 2 and was diagnosed as having COVID-19 pneumonia via polymerase chain reaction. She was refractory to treatment with levofloxacin, lopinavir, and ritonavir, while her condition improved after beginning HCQ therapy without severe side effects. We show the tolerability of HCQ therapy for 27 patients treated in our hospital. In total, 21 adverse events occurred in 20 (74%) patients, namely, diarrhea in 11 (41%) patients, and elevated levels of both aspartate aminotransferase and alanine transaminase in 10 (37%) patients. All seven grade ≥ 4 adverse events were associated with the deterioration in COVID-19 status. No patients discontinued HCQ treatment because of HCQ-related adverse events. Two patients (7%) died of COVID-19 pneumonia. In conclusion, HCQ therapy that had been performed for COVID-19 was well-tolerated in our case series.

Azithromycin ameliorated cigarette smoke-induced airway epithelial barrier dysfunction by activating Nrf2/GCL/GSH signaling pathway

BACKGROUND

Airway epithelium is the first barrier against environmental insults, and epithelial barrier dysfunction caused by cigarette smoke (CS) is particularly relevant to chronic obstructive pulmonary disease (COPD) progression. Our study was to determine whether Azithromycin (AZI) ameliorates CS-induced airway epithelial barrier dysfunction and the underlying mechanisms.

METHODS

Primary bronchial epithelial cells (PBECs), human bronchial epithelial cells (HBECs), Sprague Dawley rats and nuclear factor erythroid 2-related factor 2 (Nrf2)-/- mice were pretreated with AZI and subsequently exposed to CS. Transepithelial electronic resistance (TEER), junction proteins as well as pro-inflammatory cytokines and apoptosis markers were examined to assess epithelial barrier dysfunction. Metabolomics study was applied to explore the underlying mechanism of AZI.

RESULTS

CS-induced TEER decline and intercellular junction destruction, accompanied with inflammatory response and cell apoptosis in PBECs were restored by AZI dose-dependently, which were also observed in CS-exposed rats. Mechanistically, GSH metabolism pathway was identified as the top differentially impacted pathway and AZI treatment upregulated the activities of glutamate cysteine ligase (GCL) and the contents of metabolites in GSH metabolic pathway. Furthermore, AZI apparently reversed CS-induced Nrf2 suppression, and similar effects on airway epithelial barrier dysfunction were also found for Nrf2 agonist tert-butylhydroquinone and vitamin C. Finally, deletion of Nrf2 in both HBECs and C57BL/6N mice aggravated CS-induced GSH metabolism imbalance to disrupt airway epithelial barrier and partially deprived the effects of AZI.

CONCLUSION

These findings suggest that the clinical benefits of AZI for COPD management are related with the protection of CS-induced airway epithelial barrier dysfunction via activating Nrf2/GCL/GSH pathway, providing potential therapeutic strategies for COPD.

Complex roles of TGF-β signaling pathways in lung development and bronchopulmonary dysplasia

As survival of extremely preterm infants continues to improve, there is also an associated increase in bronchopulmonary dysplasia (BPD), one of the most significant complications of preterm birth. BPD development is multifactorial resulting from exposure to multiple antenatal and postnatal stressors. BPD has both short-term health implications and long-term sequelae including increased respiratory, cardiovascular, and neurological morbidity. Transforming growth factor β (TGF-β) is an important signaling pathway in lung development, organ injury, and fibrosis and is implicated in the development of BPD. This review provides a detailed account on the role of TGF-β in antenatal and postnatal lung development, the effect of known risk factors for BPD on the TGF-β signaling pathway, and how medications currently in use or under development, for the prevention or treatment of BPD, affect TGF-β signaling.

"The effect of 48-weeks azithromycin therapy on levels of soluble biomarkers associated with HIV-associated chronic lung disease"

OBJECTIVES

HIV-associated immune activation contributes to chronic lung disease (CLD) in children and adolescents living with HIV. Azithromycin has immunomodulatory and anti-microbial properties that may be useful for treating HIV-associated CLD (HCLD). This study describes the effect of azithromycin on expression of plasma soluble biomarkers in children and adolescents with HCLD.

METHODS

This study was nested within a multi-site double-blind, placebo controlled, randomised controlled trial (RCT) of azithromycin in individuals aged 6-19 years with HCLD (defined as FEV1 z-score < -1) in Malawi and Zimbabwe (BREATHE (NCT02426112)). Participants were randomized 1:1 to once-weekly oral azithromycin with weight-based dosing, for 48 weeks, or placebo. Twenty-six plasma soluble biomarkers were measured on a MagPix Luminex instrument at enrolment, after 48-weeks of treatment and 24-weeks after treatment cessation. Mixed effects models were constructed to compare biomarker expression across treatment and placebo groups.

RESULTS

Weekly azithromycin was associated with reduced levels of C-Reactive Protein (CRP), E-Selectin, Matrix metalloproteinase 10 (MMP-10). Treatment effects for all soluble biomarkers were not sustained 24-weeks after treatment cessation with biomarker expression returning to pre-treatment levels.

CONCLUSIONS

We observed real-world effects of azithromycin on acute inflammation, neutrophil accumulation, and extracellular matrix degradation, that were not sustained after treatment cessation. These results are pertinent when using azithromycin for its immunomodulatory properties, or targeting pathways represented by the soluble biomarkers in this study.

Erythromycin Restores Osteoblast Differentiation and Osteogenesis Suppressed by Porphyromonas gingivalis Lipopolysaccharide

The macrolide erythromycin (ERM) inhibits excessive neutrophil accumulation and bone resorption in inflammatory tissues. We previously reported that the expression of developmental endothelial locus-1 (DEL-1), an endogenous anti-inflammatory factor induced by ERM, is involved in ERM action. Furthermore, DEL-1 is involved in the induction of bone regeneration. Therefore, in this study, we investigated whether ERM exerts an osteoblastogenic effect by upregulating DEL-1 under inflammatory conditions. We performed in vitro cell-based mechanistic analyses and used a model of Porphyromonas gingivalis lipopolysaccharide (LPS)-induced periodontitis to evaluate how ERM restores osteoblast activity. In vitro, P. gingivalis LPS stimulation suppressed osteoblast differentiation and bone formation. However, ERM treatment combined with P. gingivalis LPS stimulation upregulated osteoblast differentiation-related factors and Del1, indicating that osteoblast differentiation was restored. Alveolar bone resorption and gene expression were evaluated in a periodontitis model, and the results confirmed that ERM treatment increased DEL-1 expression and suppressed bone loss by increasing the expression of osteoblast-associated factors. In conclusion, ERM restores bone metabolism homeostasis in inflammatory environments possibly via the induction of DEL-1.

Antibiotic-Therapy-Induced Gut Dysbiosis Affecting Gut Microbiota-Brain Axis and Cognition: Restoration by Intake of Probiotics and Synbiotics

Antibiotic therapy through short-term or repeated long-term prescriptions can have several damaging effects on the normal microbiota of the gastrointestinal tract. Changes in microbiota could be multiple including decreased diversity of species in gut microbiota, changed metabolic activity, and the occurrence of antibiotic-resistant strains. Antibiotic-induced gut dysbiosis in turn can induce antibiotic-associated diarrhoea and recurrent infections caused by Clostridioides difficile. There is also evidence that the use of different chemical classes of antibiotics for the treatment of a variety of ailments can lead to several health issues including gastrointestinal, immunologic, and neurocognitive conditions. This review discusses gut dysbiosis, its symptoms and one important cause, which is antibiotic therapy for the induction of gut dysbiosis. Since the maintenance of good gut health is important for the well-being and functioning of physiological and cognitive activities through the normal gut-microbiota-brain relationship, the condition of dysbiosis is not desirable. Specific therapies are prescribed by medical practitioners for the cure of a variety of ailments, and, if the prescription of antibiotics becomes unavoidable, there is a possibility of the onset of gut dysbiosis as the side or after effects. Therefore, the restoration of imbalanced gut microbiota to its balanced condition becomes necessary. A healthy relationship between gut microbiota and the brain can be achieved with the introduction of probiotic strains into the gut in a practical and consumer-friendly way, such as consumption of food and beverages prepared with the use of characterised probiotic species, fermented foods as the potential biotics, or synbiotic supplements.

First-line antibiotic treatment in patients with localized extragastric mucosa-associated lymphoid tissue lymphoma

Between January 2010 and December 2015, we enrolled 28 patients with stage IEI/IIE1 extragastric mucosa-associated lymphoid tissue (MALT) lymphoma who received first-line antibiotic treatment, after informing them about the pros and cons of alternative therapies. In addition, during the same period, 64 patients with stage IE/IIE1 disease who received conventional treatment were selected as the control group. The most common primary sites were the ocular adnexal area (17 cases), followed by the salivary glands (four cases), pulmonary (three cases), and thyroid, trachea, larynx, and colon region (one case each). First-line antibiotic treatment resulted in an overall response rate of 57.1%: 12 patients achieved complete remission (CR), while four achieved partial remission (antibiotic-responsive tumors). Monoclonal gammopathy was significantly prevalent in antibiotic-unresponsive tumors than in antibiotic-responsive tumors (50.0% [6/12] vs. 12.5% [2/16], p = 0.044). After a median follow-up of 7 years, all patients with CR remained lymphoma-free, with 7-year event-free survival (EFS) and overall survival (OS) rates of 62.7% and 96.4%, respectively. The 7-year EFS and OS rates of patients who received conventional treatments were 73.1% and 91.1%, respectively. Compared with that noted in patients who received conventional treatment, antibiotic treatment was effective in some patients with localized extragastric MALT lymphoma.

Odhar H. Introducing Larger plate and Optimum Distribution Pattern in Microbiological assay

First, clinical sample antibiotic assay process. 1966, Appl. Microbiol. 14:2:170–177. This modified agar-disks diffusion experiment employs big glass plates to enable 81 replications per plate. With an agar punch, more than agar disks may be made fast. The savings in zone of inhibition (zoi) from high repeated concentrations of diverse antibiotics with big plates and agar-disks makes it economically possible to employ pooled any antibiotic concentrate. Methods for creating disk diffusion agar and inhibiting bacterial susceptibility degradation are provided. Preparing and maintaining assay organisms is described. Instead of diluting antibiotic tablets to a small range at various concentrations to spread the agar well, they are tested immediately to avoid contamination at the tested concentrations. This is conceivable owing to antibiotic mobility (dilution) and curvilinear computations between area and antibiotic concentrations. This approach has been adapted to many antibiotics. With this technology, vast numbers of antibiotic disks may be tested quickly and accurately. Solid media can be used for antimicrobial susceptibility testing. Solids tests are straightforward and affordable, but they aren't quantitative. Antimicrobial agent diffusion may impair the accuracy of plate-based tests. After applying the above, we evaluated this assumption using the "Eight Queens Puzzle Model" of antibiotic dispersion and a disc diffusion test to estimate the connection between agar depth and area of inhibition and to determine the ideal agar depth. Our studies with agar-diffusion in plates and agar thickness demonstrated that this model describes antibiotic zoi sizes accurately. However, linear regression to explain the link between agar thickness and growth inhibition zone for Staphylococcus aureus and Escherichia coli treated with various antibiotic discs, three groups, the first group (erythromycin) emerged-zone equal sizes for both bacteria. Both bacteria were susceptible to gentamicin and ceftriaxone. Ciprofloxacin's three-group model fit best. Streptomycin's residual deviation was the same for both bacteria. The concentration dependency in the streptomycin group was greater than linear, which may imply a range of low susceptibility rather than a single cut-off dose.

Clarithromycin for community-acquired pneumonia in adults: focus on anti-inflammatory properties

Aim. To evaluate clinical efficacy, anti-inflammatory and immunomodulatory activity of clarithromycin in adults with severe community-acquired pneumonia (sCAP). Materials and methods. A prospective observational study recruited adult hospitalized patients with verified sCAP. Clarithromycin was prescribed as a component of combination antibiotic therapy (ABT) with a -lactam antibiotic (AB). The choice of -lactam AB was carried out by the attending physician in accordance with national clinical guidelines and routine practice of the medical institution. Along with assessment clinical efficacy, the dynamics of inflammatory markers in blood serum was recorded: C-reactive protein, procalcitonin (PCT), tumor necrosis factor , interleukins 1-beta (IL-1) and interleukin 6 (IL-6). The total duration of ABT was 714 days. Results. Altogether 20 patients (13 males, 7 females) aged from 18 to 84 years old were enrolled. As a result of the use of combined ABT with -lactam AB and clarithromycin, a significant decrease in the level of C-reactive protein was noted by the 35th day of therapy (from 74.6 to 14.1 mg/l). An increase in serum PCT was observed in half of the patients; during treatment, the level of PCT significantly decreased. Similar dynamics was detected for IL-6 its content in the blood serum decreased by the time of the end of ABT by 6.8 times compared with the baseline. A decrease in the level of tumor necrosis factor to the reference value was observed in most patients already in the early stages by 35 days of ABT. The majority of patients showed positive dynamics of clinical signs and symptoms with resolution of respiratory failure and other complications of sCAP. In almost half of the patients, the criteria for clinical stability were achieved in the early stages, which made it possible to switch to oral ABT. Conclusion. The results of the study are consistent with literature data indicating a rapid decrease in inflammatory markers when clarithromycin is administered to patients with sCAP. Its results can be a starting point for comparative randomized trials assessing both clinical outcomes and immunological parameters when using different classes of antibiotics for the treatment of sCAP.

Immunomodulatory role of azithromycin: Potential applications to radiation-induced lung injury

Radiation-induced lung injury (RILI) including radiation-induced pneumonitis and radiation-induced pulmonary fibrosis is a side effect of radiotherapy for thoracic tumors. Azithromycin is a macrolide with immunomodulatory properties and anti-inflammatory effects. The immunopathology of RILI that results from irradiation is robust pro-inflammatory responses with high levels of chemokine and cytokine expression. In some patients, pulmonary interstitial fibrosis results usually due to an overactive immune response. Growing clinical studies recently proposed that the anti-inflammatory and immunomodulatory effects of azithromycin may benefit patients with acute lung injury. It has been shown potential benefits for patients with RILI in preclinical studies. Azithromycin has a variety of immunomodulatory effect to improve the process of disease, including inhibition of pro-inflammatory cytokines production participating in the regulatory function of macrophages, changes in autophagy, and inhibition of neutrophil influx. We review the published evidence of mechanisms of azithromycin, and focus on the potential effect of azithromycin on the immune response to RILI.

A Case of Multidrug-Resistant Klebsiella pneumoniae Treated with Carrimycin

One of the most pressing emerging issues in bacterial resistance is multidrug-resistant Klebsiella pneumoniae. The treatment of K. pneumoniae infections is often problematic because of the lack of available therapeutic options, leading to negative effects on morbidity, mortality, and healthcare-associated costs. Carrimycin is a macrolide antibiotic with good antibacterial effects. In this study, we report a patient diagnosed with multidrug-resistant K. pneumoniae infection who was treated with carrimycin. The patient presented with cough, expectoration, dyspnea, and severe hypoxemia requiring noninvasive ventilation. We successively used a variety of antibiotics, including meropenem, tigecycline, and polymyxin, with unsatisfactory results. Finally, we used carrimycin, and the patient's condition improved, resulting in hospital discharge. Therefore, for patients with multidrug-resistant K. pneumoniae infection that does not respond to conventional anti-infective treatments, carrimycin can be considered a treatment option.

Antibiotics with Antiviral and Anti-Inflammatory Potential Against Covid-19: A Review

In Covid-19 cases, elderly patients in long-term care facilities, children younger than five years with moderate symptoms, and patients admitted to ICU or with comorbidities are at a high risk of coinfection, as suggested by the evidence. Thus, in these patients, antibiotic therapy based on empirical evidence is necessary. Finding appropriate antimicrobial agents, especially with antiviral and anti-inflammatory properties, is a promising approach to target the virus and its complications, hyper-inflammation, and microorganisms resulting in co-infection. Moreover, indiscriminate use of antibiotics can be accompanied by Clostridioides difficile colitis, the emergence of resistant microorganisms, and adverse drug reactions, particularly kidney damage and QT prolongation. Therefore, rational administration of efficient antibiotics is an important issue. The main objective of the present review is to provide a summary of antibiotics with possible antiviral activity against SARS-CoV-2 and anti-immunomodulatory effects to guide scientists for further research. Besides, the findings can help health professionals in the rational prescription of antibiotics in Covid-19 patients with a high risk of co-infection.

Factors Associated with Extended-spectrum β-lactamase-producing Enterobacteria Isolated from Respiratory Samples

Objective Although extended-spectrum β-lactamase (ESBL)-producing bacteria are a global threat, as they may cause respiratory infection, the factors associated with the isolation of these bacteria from sputum remain unclear. We therefore explored the factors related to ESBL-producing Klebsiella pneumoniae and Escherichia coli isolated from sputum samples. Patients and Methods This study included consecutive patients admitted to our department from 2010 to 2021 with K. pneumoniae or E. coli isolated from their sputum. The patients were categorized into ESBL-producing and non-ESBL-producing groups, and the factors associated with ESBL-producing bacteria isolation were assessed using a binomial logistic regression analysis. Results We included 82 patients, and ESBL-producing pathogens were isolated from 23 (28%). The usage rates of cephem [odds ratio (OR) 4.000, 95% confidence interval (CI) 1.402-11.409, p=0.010], quinolone (OR 2.961, 95% CI 1.097-7.996, p=0.032), and macrolide (OR 4.273, 95% CI 1.518-12.028, p=0.006) in the past year were significantly higher in the ESBL-producing group than in the non-ESBL-producing group. The multivariate analysis revealed that the applications of cephem (adjusted OR: 4.130, 95% CI: 1.233-13.830, p=0.021) and macrolide (adjusted OR: 6.365, 95% CI: 1.922-21.077, p=0.002) was independently associated with the isolation of ESBL-producing bacteria. Conclusions A history of cephem and macrolide use can be considered a risk factor for ESBL-producing bacteria isolation from sputum samples. Physicians need to consider these risk factors when determining antibiotics for the treatment of patients with respiratory infections.

Targeting malaria parasites with novel derivatives of azithromycin

Introduction

The spread of artemisinin resistant Plasmodium falciparum parasites is of global concern and highlights the need to identify new antimalarials for future treatments. Azithromycin, a macrolide antibiotic used clinically against malaria, kills parasites via two mechanisms: 'delayed death' by inhibiting the bacterium-like ribosomes of the apicoplast, and 'quick-killing' that kills rapidly across the entire blood stage development.

Methods

Here, 22 azithromycin analogues were explored for delayed death and quick-killing activities against P. falciparum (the most virulent human malaria) and P. knowlesi (a monkey parasite that frequently infects humans).

Results

Seventeen analogues showed improved quick-killing against both Plasmodium species, with up to 38 to 20-fold higher potency over azithromycin after less than 48 or 28 hours of treatment for P. falciparum and P. knowlesi, respectively. Quick-killing analogues maintained activity throughout the blood stage lifecycle, including ring stages of P. falciparum parasites (<12 hrs treatment) and were >5-fold more selective against P. falciparum than human cells. Isopentenyl pyrophosphate supplemented parasites that lacked an apicoplast were equally sensitive to quick-killing analogues, confirming that the quick killing activity of these drugs was not directed at the apicoplast. Further, activity against the related apicoplast containing parasite Toxoplasma gondii and the gram-positive bacterium Streptococcus pneumoniae did not show improvement over azithromycin, highlighting the specific improvement in antimalarial quick-killing activity. Metabolomic profiling of parasites subjected to the most potent compound showed a build-up of non-haemoglobin derived peptides that was similar to chloroquine, while also exhibiting accumulation of haemoglobin-derived peptides that was absent for chloroquine treatment.

Discussion

The azithromycin analogues characterised in this study expand the structural diversity over previously reported quick-killing compounds and provide new starting points to develop azithromycin analogues with quick-killing antimalarial activity.

Reversible Bronchial Obstruction in Primary Ciliary Dyskinesia

BACKGROUND

Inhaled bronchodilators are frequently used among patients with primary ciliary dyskinesia (PCD), although neither the effectiveness nor the prevalence of their use is known, due to the paucity of relevant studies.

METHODS

This is a retrospective analysis of pre- and post-bronchodilator spirometry results, of patients with PCD from two centers. Correlations were examined of bronchodilator response, with asthma and atopy markers.

RESULTS

Of 115 patients, 46 (40%) completed spirometry pre- and post-bronchodilation. Of these, 26 (56.5%) demonstrated reversible airway obstruction (increase in %FEV₁ predicted ≥ 10%). Obstruction reversibility was not found to be associated with a family history of asthma, blood eosinophil level, elevated IgE, or atopy symptoms. Of the 46 patients who completed bronchodilator spirometry, 29 (63%) were regularly using bronchodilators and inhaled corticosteroids.

CONCLUSIONS

More than half of patients with PCD presented with reversible airway obstruction, without any correlation to markers of personal or familial atopy. Inhaled bronchodilators and corticosteroid therapies are commonly used for treating PCD. Evaluating bronchodilator response should be considered, and its effectiveness should be further studied.

Electrospun Azithromycin-Laden Gelatin Methacryloyl Fibers for Endodontic Infection Control

This study was aimed at engineering photocrosslinkable azithromycin (AZ)-laden gelatin methacryloyl fibers via electrospinning to serve as a localized and biodegradable drug delivery system for endodontic infection control. AZ at three distinct amounts was mixed with solubilized gelatin methacryloyl and the photoinitiator to obtain the following fibers: GelMA+5%AZ, GelMA+10%AZ, and GelMA+15%AZ. Fiber morphology, diameter, AZ incorporation, mechanical properties, degradation profile, and antimicrobial action against Aggregatibacter actinomycetemcomitans and Actinomyces naeslundii were also studied. In vitro compatibility with human-derived dental pulp stem cells and inflammatory response in vivo using a subcutaneous rat model were also determined. A bead-free fibrous microstructure with interconnected pores was observed for all groups. GelMA and GelMA+10%AZ had the highest fiber diameter means. The tensile strength of the GelMA-based fibers was reduced upon AZ addition. A similar pattern was observed for the degradation profile in vitro. GelMA+15%AZ fibers led to the highest bacterial inhibition. The presence of AZ, regardless of the concentration, did not pose significant toxicity. In vivo findings indicated higher blood vessel formation, mild inflammation, and mature and thick well-oriented collagen fibers interweaving with the engineered fibers. Altogether, AZ-laden photocrosslinkable GelMA fibers had adequate mechanical and degradation properties, with 15%AZ displaying significant antimicrobial activity without compromising biocompatibility.

Pleiotropic effects of antibiotics on T cell metabolism and T cell-mediated immunity

T cells orchestrate adaptive and innate immune responses against pathogens and transformed cells. However, T cells are also the main adaptive effector cells that mediate allergic and autoimmune reactions. Within the last few years, it has become abundantly clear that activation, differentiation, effector function, and environmental adaptation of T cells is closely linked to their energy metabolism. Beyond the provision of energy equivalents, metabolic pathways in T cells generate building blocks required for clonal expansion. Furthermore, metabolic intermediates directly serve as a source for epigenetic gene regulation by histone and DNA modification mechanisms. To date, several antibiotics were demonstrated to modulate the metabolism of T cells especially by altering mitochondrial function. Here, we set out to systematically review current evidence about how beta-lactam antibiotics, macrolides, fluoroquinolones, tetracyclines, oxazolidinones, nitroimidazoles, and amphenicols alter the metabolism and effector functions of CD4+ T helper cell populations and CD8+ T cells in vitro and in vivo. Based on this evidence, we have developed an overview on how the use of these antibiotics may be beneficial or detrimental in T cell-mediated physiological and pathogenic immune responses, such as allergic and autoimmune diseases, by altering the metabolism of different T cell populations.

Unmet needs in pneumonia research: a comprehensive approach by the CAPNETZ study group

Introduction

Despite improvements in medical science and public health, mortality of community-acquired pneumonia (CAP) has barely changed throughout the last 15 years. The current SARS-CoV-2 pandemic has once again highlighted the central importance of acute respiratory infections to human health. The “network of excellence on Community Acquired Pneumonia” (CAPNETZ) hosts the most comprehensive CAP database worldwide including more than 12,000 patients. CAPNETZ connects physicians, microbiologists, virologists, epidemiologists, and computer scientists throughout Europe. Our aim was to summarize the current situation in CAP research and identify the most pressing unmet needs in CAP research.

Methods

To identify areas of future CAP research, CAPNETZ followed a multiple-step procedure. First, research members of CAPNETZ were individually asked to identify unmet needs. Second, the top 100 experts in the field of CAP research were asked for their insights about the unmet needs in CAP (Delphi approach). Third, internal and external experts discussed unmet needs in CAP at a scientific retreat.

Results

Eleven topics for future CAP research were identified: detection of causative pathogens, next generation sequencing for antimicrobial treatment guidance, imaging diagnostics, biomarkers, risk stratification, antiviral and antibiotic treatment, adjunctive therapy, vaccines and prevention, systemic and local immune response, comorbidities, and long-term cardio-vascular complications.

Conclusion

Pneumonia is a complex disease where the interplay between pathogens, immune system and comorbidities not only impose an immediate risk of mortality but also affect the patients’ risk of developing comorbidities as well as mortality for up to a decade after pneumonia has resolved. Our review of unmet needs in CAP research has shown that there are still major shortcomings in our knowledge of CAP.

Erythromycin: an alternative for the management of oral mucositis?

BACKGROUND

Oral mucositis (OM) is an important acute adverse effect of anticancer therapy. This condition presents high morbidity and may lead to the suspension of anticancer therapy.

MATERIAL AND METHODS

We reviewed the literature on the pathobiology of OM and the properties of erythromycin (EM), to consider the possibility of its use for the prevention and treatment of OM. We searched the PubMed, Scopus and Web of Science databases and selected complete articles published in English or Spanish that met the inclusion criteria. The search terms "erythromycin", "inflammation", "immunomodulation" and "oral mucositis" were used.

RESULTS

The control of free radicals, transcription factors and pro-inflammatory cytokines has been considered as the key to the management of OM. EM has the ability to modulate oxidative stress, acts on the transcriptional system and inhibits the production of several cytokines that have been directly implicated in OM pathobiology.

CONCLUSIONS

The present review suggests that EM could be effective in the treatment of OM. Experimental studies investigating the use of EM in OM should be encouraged.

Azithromycin and Ceftriaxone Differentially Activate NLRP3 in LPS Primed Cancer Cells

Background: Cancer patients are prescribed antibiotics, such as macrolides and lactamides, for infection treatment. However, the effect of these antibiotics on NLRP3 activation remains largely unknown. Method: Lung cancer (A549) and prostate cancer (PC3) cell lines were primed with lipopolysaccharide (LPS) to activate NLRP3 transcription. Cells were then treated with azithromycin (Az) or ceftriaxone (Cf). NLRP3 activation was analyzed by qPCR, Western blot, and ELISA. Cell growth and viability were assessed by real-time cell analysis and Annexin V expression. Levels of 41 cytokines were also analyzed using a multiplex assay. Results: LPS-Az activated transcription of NLRP3, Pro-CASP-1, and Pro-IL-1β in A549 cells, while failing to upregulate NLRP3 and Pro-IL-1β in PC3 cells. LPS-Az decreased the secretion of pro-inflammatory cytokines while it induced the pro-angiogenic factors in A549 and PC3 cells. In contrast, LPS-Cf suppressed the expression of NLRP3-associated genes, NLRP3 protein expression, the inflammatory cytokine secretion in A549 and PC3 cells. LPS-Az and LPS-Cf had a limited effect on cell growth and viability. Discussion: Our data suggest that Cf could suppress LPS induced NLRP3, which should be considered when selecting antibiotics for cancer treatment. In contrast, the effect of Az on LPS primed NLRP3 and the inflammatory cytokines production appears to depend on the cancer cell origin. Therefore, these data indicate that considerations are required when selecting Az for the treatment of cancer patients.

The Azithromycin Pro-Drug CSY5669 Boosts Bacterial Killing While Attenuating Lung Inflammation Associated with Pneumonia Caused by Methicillin-Resistant Staphylococcus aureus

Antibiotic resistance is a major problem, with methicillin-resistant Staphylococcus aureus (MRSA) being a prototypical example in surgical and community-acquired infections. S. aureus, like many pathogens, is immune evasive and able to multiply within host immune cells. Consequently, compounds that aid host immunity (e.g., by stimulating the host-mediated killing of pathogens) are appealing alternatives or adjuncts to classical antibiotics. Azithromycin is both an antibacterial and an immunomodulatory drug that accumulates in immune cells. We set out to improve the immunomodulatory properties of azithromycin by coupling the immune activators, nitric oxide and acetate, to its core structure. This new compound, designated CSY5669, enhanced the intracellular killing of MRSA by 45% ± 20% in monocyte-derived macrophages and by 55% ± 15% in peripheral blood leukocytes, compared with untreated controls. CSY5669-treated peripheral blood leukocytes produced fewer proinflammatory cytokines, while in both monocyte-derived macrophages and peripheral blood leukocytes, phagocytosis, ROS production, and degranulation were unaffected. In mice with MRSA pneumonia, CSY5669 treatment reduced inflammation, lung pathology and vascular leakage with doses as low as 0.01 μmol/kg p.o. CSY5669 had diminished direct in vitro antibacterial properties compared with azithromycin. Also, CSY5669 was immunomodulatory at concentrations well below 1% of the minimum inhibitory concentration, which would minimize selection for macrolide-resistant bacteria if it were to be used as a host-directed therapy. This study highlights the potential of CSY5669 as a possible adjunctive therapy in pneumonia caused by MRSA, as CSY5669 could enhance bacterial eradication while simultaneously limiting inflammation-associated pathology.