Azithromycin: The First Broad-spectrum Therapeutic

Sulfadoxine-pyrimethamine alone or with azithromycin for the intermittent preventive treatment of malaria in pregnancy: protocol for a systematic review and meta-analysis

INTRODUCTION

Increasing Plasmodium resistance levels to sulfadoxine-pyrimethamine (SP) threaten the effectiveness of intermittent preventive treatment in pregnancy (IPTp) and have prompted the evaluation of alternative strategies. Azithromycin (AZ) could have add-on effects on malaria and treat sexually transmitted infections (STIs), both conditions described as major causes of adverse pregnancy outcomes (APO). Inconsistent findings on the utility of AZ for the prevention of APO were reported; however, thus far, no comprehensive meta-analytic synthesis of data has been published. This review aims to investigate the effects of SP+AZ administered in women as IPTp on the risk of low birth weight in malaria-endemic areas.

METHODS AND ANALYSIS

Eligible studies will be identified through a pre-established search strategy in several electronic databases (Medline, Cochrane Library, Web of Science, EMBASE, WHO International Clinical Trials Registry Platform, ClinicalTrials.gov and AJOL) and will comprise peer-reviewed papers reporting original data on the effects of SP+AZ on the risk of APO. Only randomised controlled trials published until 30 September 2024 in English or French will be included. IPTp with SP+AZ regimens (intervention) will be compared with IPTp with SP alone or with a placebo (control). As primary outcomes, data on the frequency of low birth weight will be collected. Secondary outcomes include the rates of stillbirth, preterm birth, miscarriage and neonatal death. Data will be extracted independently by two reviewers using a predefined extraction form. If the data quality allows for quantitative synthesis, a fixed-effects meta-analysis will be conducted if there is low inter-study heterogeneity. Otherwise, the random-effects meta-analysis will be conducted to take into account uncertainty in pooled estimates that could be due to inter-study heterogeneity. The review protocol was designed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses Protocols (PRISMA-P) guidelines.

ETHICS AND DISSEMINATION

Ethical clearance is not needed as the data will be from already published studies in which informed consent and ethical approval were obtained by primary investigators. Our dissemination plan includes the publication in a peer-reviewed journal as well as conference presentations.

PROSPERO REGISTRATION NUMBER

CRD42020149592.

Optimization and preparation of in-situ mucoadhesive gel of azithromycin hydroxypropyl-β-cyclodextrin inclusion complex against upper respiratory tract infections

BACKGROUND

Azithromycin (ATM) has limitations, such as poor oral bioavailability and gastrointestinal (GI) side effects that restrict its widespread application.

OBJECTIVE

To develop a localized hydroxy propyl β-cyclodextrin (HP-βCD) inclusion complex-based in situ pH-responsive mucoadhesive gel of azithromycin (ATM) and evaluate its performance for the treatment of upper respiratory tract infections (URTIs).

METHODS

According to the phase solubility diagram, the ATM HP-βCD complex was prepared and analyzed by FT-IR, DSC, and SEM. Then, using a quality-by-design approach, pH-responsive in-situ gel was prepared. It was characterized in terms of their gelling capacity, pH, spreadability, swelling index, rheological properties and antimicrobial potential.

RESULTS

ATM HP- βCD complex 20-fold increased solubility of ATM, i.e., 49.84 ± 1.39 µg/mL with improved dissolution profile compared to pure ATM. Optimized formulation characterized by its gelation pH (6.7), time (1.59 min), and viscosity (1607.9 Pa.s). The developed gel showed a good spreadability index (322.6 ± 0.5%), swelling index (98.26 ± 1.54% after 10 h) and mucoadhesive strength (589 g/cm2). Also, it exhibits a sustained drug release profile for 12 h(94 ± 1.37%) and a broader zone of Staphylococcus aureus growth inhibition (31 ± 3.54 mm).

CONCLUSION

The developed mucoadhesive in situ gels demonstrated promising in vivo performance, primarily due to their effective antimicrobial activity. In vivo, local retention studies confirmed that the formulations adhered to the throat mucosa and remained in place for up to 24 h after application. The findings presented here suggested that this localized delivery system could serve as a useful strategy for improving the therapeutic effects of ATM against URTIs.

An added value of azithromycin: mitigation of doxorubicin-associated oxidative damage and genotoxicity in normal human bronchial epithelium cells

Doxorubicin, a well-known and widely used antineoplastic agent with direct ROS-accumulating activity, has proven effective in treating various cancer types. However, its non-specific cytotoxicity towards non-cancerous cells prompts concerns regarding potential adverse effects. Azithromycin is an antibiotic for treating bacterial infections and an anti-inflammatory agent, particularly beneficial in managing respiratory conditions like bronchitis and sinusitis. Despite azithromycin's well-documented antibacterial properties, its potential cellular/genomic protective effects remain unexplored. As an in vitro model, BEAS-2B cells (normal human bronchial epithelium cells) were employed in this study to assess whether azithromycin possesses any protective properties against doxorubicin-induced cellular toxicity. Cells in pretreatment culture were treated to various amounts of azithromycin (3.125, 6.25, 12.5, 25, and 50 μg/ml) in combination with doxorubicin at IC50 (0.08 μg/ml). Doxorubicin at 0.08 μg/ml highlighted cytotoxicity, oxidative stress, and genotoxicity. Azithromycin at 25 and 50 μg/ml markedly modulated oxidative stress and genomic damage by decreasing the ROS and LPO amounts and suppressing DNA fragmentation in the comet assay parameters. Consequently, azithromycin may be regarded as a cytomodulating, antigenotoxic, and antioxidant agent.

Gallic acid synergistically enhances the antibacterial activity of azithromycin in MRSA

The rise of antibiotic resistance in existing pathogens has been identified as a major threat to global healthcare in the twenty-first century. This resistance has consequences such as increased cost and prolonged hospital stays, treatment failure, and ultimately increased risk of patient mortality. It is therefore imperative to develop strategies to combat drug resistance. Combined treatment of common antibiotics and natural compounds is one of the most effective methods against resistant bacterial infections. Gallic acid (GA) is a natural secondary metabolite abundantly found in plants and has significant medicinal effects in various aspects of health. In this research, the antibacterial effects of azithromycin (AZM) and GA alone and in combination with each other were investigated on planktonic and biofilm forms of methicillin-sensitive Staphylococcus aureus (MSSA), methicillin-resistant Staphylococcus aureus (MRSA), and Pseudomonas aeruginosa (P. aeruginosa). The results showed that the combination of AZM/GA had an additive effect against MSSA and P. aeruginosa and a synergistic effect against MRSA. In addition, combining these two agents significantly reduced the minimum biofilm inhibitory concentration (MBIC) of AZM and GA in the MRSA strain. Finally, the level of ROS generation in the effect of AZM plus GA was evaluated in the bacteria. Among the studied strains, ROS production was significantly increased in combination treatment compared to AZM alone in MRSA. The results show that the combination of AZM and GA has a significant effect against MRSA and can be considered as an effective treatment option.

Injectable thermosensitive antibiotic-laden chitosan hydrogel for regenerative endodontics

Injectable biomaterials, such as thermosensitive chitosan (CH)-based hydrogels, present a highly translational potential in dentistry due to their minimally invasive application, adaptability to irregular defects/shapes, and ability to carry therapeutic drugs. This work explores the incorporation of azithromycin (AZI) into thermosensitive CH hydrogels for use as an intracanal medication in regenerative endodontic procedures (REPs). The morphological and chemical characteristics of the hydrogel were assessed by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and Fourier transform infrared spectroscopy (FTIR). The thermosensitivity, gelation kinetics, compressive strength, cytocompatibility, and antibacterial efficacy were evaluated according to well-established protocols. An in vivo model of periapical disease and evoked bleeding in rats' immature permanent teeth was performed to determine disinfection, tissue repair, and root formation. AZI was successfully incorporated into interconnected porous CH hydrogels, which retained their thermosensitivity. The mechanical and rheological findings indicated that adding AZI did not adversely affect the hydrogels' strength and injectability. Incorporating 3 % and 5 % AZI into the hydrogels led to minimal cytotoxic effects compared to higher concentrations while enhancing the antibacterial response against endodontic bacteria. AZI-laden hydrogel significantly decreased E. faecalis biofilm compared to the controls. Regarding tissue response, the 3 % AZI-laden hydrogel improved mineralized tissue formation and vascularization compared to untreated teeth and those treated with double antibiotic paste. Our findings demonstrate that adding 3 % AZI into CH hydrogels ablates infection and supports neotissue formation in vivo when applied to a clinically relevant model of regenerative endodontics.

Gallic and glycyrrhetinic acids prevent azithromycin-induced liver damage in rats by mitigating oxidative stress and inflammation

Natural products like gallic acid (GA), a phenolic compound, and glycyrrhetinic acid (GLA), a pentacyclic triterpene, have been shown to exhibit antioxidant, ant-inflammatory, and hepatoprotective properties. This study aims to investigate the protective effects of GA, GLA and their combination and to explore their underlying mechanisms against acute liver damage induced by azithromycin (AZM) in rats. Seven groups of male Wistar rats were used namely control, GA, GLA, AZM, AZM + GA, AZM + GLA, and AZM + GA + GLA groups. We treated the rats for 21 days, administering GA and GLA at 50 mg/kg one week prior to AZM (30 mg/kg). Serum levels of aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase in rats AZM-induced and pre-treated with of GA, GLA, and combination therapy were much lower than those in the AZM group Elevated levels of glutathione, catalase, and superoxide dismutase in preventive rats demonstrated that GA, GLA, and their combinations notably reduced AZM-induced malondialdehyde levels, an oxidative stress marker, improving the antioxidant system in those groups. Furthermore, GA, GLA, and their combinations reduced pro-inflammatory cytokines, such as tumor necrosis factor-α and nuclear factor kappa beta (NF-kB), thus reversing hepatic inflammation. We also discovered that AZM down-regulated nuclear factor erythroid 2-related factor 2 (Nrf2), and that its normal levels were restored post treatments with GA, GLA, and their combination suggesting a Nrf2 signaling pathway-mediated prevention of AZM-induced liver damage. In conclusion, GA, GLA, and their combination protected rats against AZM-induced liver injury through their demonstrated ability to lower oxidative stress and inflammation by preventing downregulation of Nrf2 and upregulation of NF-kB. After determining their efficacy and safety in clinical settings in future studies, GA and GLA could potentially make useful therapeutic drugs to mitigate AZM-induced hepatotoxicity.

Therapeutic effect of pH responsive Magainin II modified azithromycin plus curcumin micelles in different depth models of MRSA infection

Methicillin-resistant Staphylococcus aureus (MRSA) is a major pathogen responsible for serious infections in humans. The overuse of antibiotics has led to the evolution of resistance genes in bacteria. This study aimed to develop a pH-responsive micelle, loaded with therapy drugs and modified with antimicrobial peptides, to treat drug-resistant bacterial infections at varying depths. pH-responsive micelles containing azithromycin and curcumin, modified with Magainin II, were prepared using the thin-film dispersion method. The physicochemical properties of the micelles were characterized, and their targeting properties and therapeutic effects on bacterial infections were investigated both in vivo and in vitro across various depths. The micelles demonstrated excellent targeting of bacterial infection sites and released drugs in response to degradation at the disease site. The combination of curcumin and azithromycin effectively mitigated bacterial resistance through multiple mechanisms, enhancing the antibacterial effect while reducing the required azithromycin dosage and associated toxicity. In infection models of varying depths-skin, muscle, and lungs-the micelles exhibited strong antibacterial, anti-biofilm, and anti-inflammatory effects with low toxicity. These findings provide a promising strategy for addressing drug-resistant bacterial infections.

Azithromycin-Loaded Nanoparticles Incorporated in Chitosan-Based Soft Hydrogels: A Novel Approach for Dental Drug Delivery

Background: Azithromycin (AZC), a BCS class II/IV antibiotic with broad-spectrum antimicrobial activity, has poor water solubility, limiting its formulation potential. This study aimed to develop and optimize AZC-based soft hydrogels for the first time for improved solubility, local controlled drug release, and local dental applications. Methods: AZC nanoparticles (based on polyvinylpyrrolidone) were synthesized via electrospinning enhanced solubility 40-fold. These were incorporated into chitosan (CS) hydrogels with varying concentrations and degrees of deacetylation (DDA), optimized using a factorial design. Hydrogels were characterized for drug release, mucoadhesion, antioxidant, anti-inflammatory, and antimicrobial properties, with Principal Component Analysis (PCA) assessing correlations. Results: Soft hydrogels with 3% CS and 80% DDA achieved sustained drug release (62.9-94.7% over 48 h), strong mucoadhesion, and enhanced biological activity. Higher CS and DDA improved antioxidant and anti-inflammatory effects due to increased free amino groups. Antimicrobial tests showed efficacy against Streptococcus mutans and Staphylococcus aureus. PCA revealed an inverse correlation between AZC release and mucoadhesion and positive correlations between release and anti-inflammatory activity. Conclusions: AZC-based soft hydrogels significantly improved solubility, controlled release, and biological activity, showing strong potential for dental drug delivery. Further clinical validation and optimization are recommended.

Azithromycin in the Management of Upper Respiratory Tract Infections (URTIs): Indian Real-Life Experience

Objective

Upper Respiratory Tract Infections (URTIs) pose a significant public health challenge worldwide. Azithromycin has been approved for its management due to broad-spectrum antibacterial properties and favorable pharmacokinetics. This study aims to evaluate the effectiveness and safety of Azithromycin in treatment of URTIs in a real-world setting.

Methods

This multicenter, retrospective, observational study was conducted across 184 Ear, Nose, and Throat (ENT) clinics in India. Medical records of adults (≥18 years) who received Azithromycin 500 mg for 5 days to treat URTIs and provided consent were retrieved. Sore throat, fever, and interference with daily activities were assessed alongside clinical signs (pharyngeal erythema, tonsillar erythema, and exudates/plugs on tonsils). Clinical global impression of change was evaluated using a 7-point rating scale. Statistical analyses included paired t-tests for mean score changes and the McNemar-Bowker test to evaluate symptom improvement from baseline to day 5.

Results

Data from 884 patients were analyzed. With 5 days of Azithromycin therapy, significant reduction in proportion of patients reporting URTI symptoms and signs was noted. Proportion of patients reporting sore throat was reduced from 95.8% to 10.4%; work absenteeism dropped from 47.9% to 1%; and fever subsided in 97.4% of patients. Clinical signs also improved notably, with moderate-to-severe pharyngeal erythema (90.9% of patients at baseline to 13.6% at day 5), tonsillar erythema (84% of patients at baseline to 9.6%), and tonsillar exudates (58.3% patients at baseline to 4.4%). Also, 97.2% of patients showed considerable improvement in their Clinical Global Impression score with Azithromycin. Adverse events were reported by 2.37% of patients.

Conclusion

Azithromycin demonstrates a significant improvement in clinical manifestations of URTIs, with a low incidence of adverse events.

Influence of soil type on bacterial growth and tolerance to experimentally added human antibiotics

The human antibiotics cefuroxime (CXM) and azithromycin (AZI) are among the most commonly prescribed. A significant portion of both are excreted and has been detected in sewage treatment plant effluents. The increasing use of such effluents in crops for irrigation and as fertilisers poses a threat to soil microbiota because of the presence of antibiotics. The lack of studies on CXM and AZI in soils hinders our understanding of their potential toxic effects on soil bacterial communities and ecosystem services. This study significantly contributes to the literature by quantifying the toxicity of CXM and AZI at varying concentrations in 12 different crop soils and tracking their evolution over time. The study also examined whether antibiotic pressure led to the development of more tolerant bacterial communities. The results of this study are the values of the logarithm of the antibiotic concentration at which 50 % of bacterial growth is inhibited (Log IC50) and indicate that both antibiotics are toxic to soil bacteria. The direct toxicity of CXM (1 day after contamination) was higher (Log IC50: 0.9 = 7.9 mg kg-1) than that of AZI (Log IC50: 3.4 = 2362 mg kg-1). However, bacterial growth was less affected by CXM over time, whereas AZI remained toxic in some soils until day 42 (Log IC50: 3.2 = 1533 mg kg-1 and 3.4 = 2291 mg kg-1, respectively). The overall results indicate that selective pressure exerted by antibiotics generates antibiotic tolerance in soils, even at the lowest antibiotic concentration studied (7.8 mg kg-1). The general trend was to increase tolerance to higher antibiotic concentrations up to the highest concentration studied (2000 mg kg-1). However, the degree of tolerance developed was highly dependent on soil type. More studies should be conducted to quantitatively assess the toxic and tolerance-developing effects of antibiotics in soils. Such information will be valuable for identifying which antibiotics pose a threat to the soil microbiota and consequently to human health.

Electrochemical Oxidative Cascade Cyclization of Alkenyl Alcohols with External Nucleophiles to Access Amino- and Hydroxy-Functionalized O-Heterocycles

A convenient electrochemical oxidative cascade cyclization of alkenes equipped with pendant alcohols with general nucleophiles was developed. Using readily available diarylmethanimine and carboxylic acids as nucleophilic sources, a broad range of internal alkene and terminal alkene substrates could produce RCO2- and Ar2CN-functionalized O-heterocycles in moderate to high yields without the requirement for external oxidants and metals. These resulting products can subsequently be hydrolyzed to yield valuable NH2- and OH-functionalized tetrahydrofurans and tetrahydropyranes under mild conditions. Importantly, the efficient conversion of secondary alcohol products to amines with complete inversion of configuration enhances the methodology, enabling the construction of 2-aryl-3-amino tetrahydrofuran with high and complementary diastereoselectivity.

Chlamydophila psittaci pneumonia followed by lower gastrointestinal ischemic necrosis: a case report

Background

Psittacosis, also known as parrot fever, is an uncommon infectious disease caused by Chlamydophila psittaci (C. psittaci). While C. psittaci infections are usually not life-threatening, the pathogenesis and associated complications are not yet fully understood.

Case description

A 54-year-old male was hospitalized due to a cough, accompanied by expectoration and dyspnea. After admission, the patient's breathing rapidly deteriorated, and despite the use of a ventilator, it was challenging to maintain respiratory function. While initiating extracorporeal membrane oxygenation (ECMO) and empirical anti-infection treatments, the alveolar lavage fluid was collected and examined by metagenomics next generation sequencing (mNGS). The mNGS result indicated C. psittaci. Subsequently, the anti-infection regimen was immediately adjusted. The respiratory function improved on the 13th day after admission, and ECMO was withdrawn. However, the patient developed abdominal distension and intestinal edema. After intravenous infusion therapy, intestinal ischemia and necrosis occurred and surgical resection was performed. The patient's condition improved after the operation and he was transferred to a local hospital for rehabilitation.

Conclusion

This case report demonstrates the development of intestinal ischemic necrosis following severe C. psittaci pneumonia. This unique association has not been reported previously and highlights the importance of potential gastrointestinal complications in severe C. psittaci pneumonia, which are often underestimated. Timely diagnoses and treatments of such infections and complications are necessary to achieve favorable clinical outcomes.

Assessing azithromycin's ecological toll: Unveiling multifaceted impacts on Poecilia reticulata THROUGH biomarker analysis

This study investigates the impact of environmentally relevant concentrations of azithromycin on Poecilia reticulata, through biomarkers at different levels. To this end, the somatic indexes of P. reticulata were evaluated, and liver and gill samples were collected and analyzed for biochemical and histopathological alterations. Azithromycin caused significant effects in P. reticulata, such as increased hepatosomatic index, altered redox responses, particularly in gills, indicating oxidative stress, and notable tissue damage in the liver and gills in a dose-dependent response manner. Principal Component Analysis highlighted differences between control and exposed groups, demonstrating the azithromycin's influence on organismal homeostasis. This research underscores the importance of understanding azithromycin action in nontarget organisms of aquatic environments.

Azithromycin induces liver injury in mice by targeting the AMPK/Nrf2 pathway

BACKGROUND

Azithromycin is an antibacterial and anti-inflammatory drug widely used for the treatment of various diseases, including those caused by atypical pathogens, bacterial or viral infections, chronic sinusitis, and bronchial asthma, particularly in pediatric patients. However, concerns have emerged regarding its hepatotoxicity and its precise mechanism of action remains unclear.

OBJECTIVE

To investigate the molecular mechanisms responsible for azithromycin-induced acute liver injury to advance our understanding of the progression and pathogenesis of antibiotic-induced liver damage, and to improve prevention and treatment strategies.

MATERIALS AND METHODS

C57BL/6 mice, Nrf2-/- mice, and primary hepatocytes were used. Primary hepatocytes from mice were isolated using a two-step perfusion method and cultured in vitro via the 'sandwich' culture model.

RESULTS

The exposure to azithromycin resulted in increased apoptosis and reactive oxygen species (ROS) levels. In mouse models, intraperitoneal administration of azithromycin at varying concentrations and time points substantially induced hepatic disarray, swelling, and dysfunction. Azithromycin markedly upregulated the mRNA and protein levels of phosphorylated adenosine-activated protein kinase (AMPK) while downregulating nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase 1 (HO-1), and NADPH: quinone oxidoreductase 1 (NQO-1). Moreover, HO-1 and NQO-1 protein levels remained largely unaffected in primary hepatocytes co-cultured with azithromycin in Nrf2-/- mice.

CONCLUSIONS

Our findings suggest that azithromycin-induced acute liver injury is mediated by suppression of Nrf2 activation and ROS production. This sheds light on the potential mechanisms involved in azithromycin-induced liver damage, underscoring the importance of exploring targeted interventions to mitigate the hepatotoxic effects.

Hyaluronic Acid-Modified Micelles of Azithromycin and Quercetin Against Infections Caused by Methicillin-Resistant Staphylococcus Aureus

Introduction

Resistance of intracellular pathogens is a challenge in microbial therapy. Methicillin-resistant Staphylococcus aureus (MRSA), which is able to persist inside the cells of infected tissues, is protected from attack by the immune system and many antimicrobial agents. To overcome these limitations, nano-delivery systems can be used for targeted therapy of intracellular MRSA.

Methods

Hyaluronic acid-modified azithromycin/quercetin micelles (HA-AZI/Qe-M) were synthesized by thin film hydration. The micelles were characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS) and Fourier transform infrared spectroscopy (FTIR), and the drug loading (DL) and encapsulation efficiency (EE) were detected by high performance liquid chromatography (HPLC). The uptake ability of RAW264.7 cells was investigated, and its distribution in mice was evaluated by in vivo imaging. The inhibitory effect of the micelles against MRSA in vitro and its ability to eliminate intracellular bacteria were evaluated. Bacterial muscle-infected mice were constructed to evaluate the therapeutic effect of the micelles on bacterial infections in vivo and the biocompatibility of the micelles was investigated.

Results

HA-AZI/Qe-M had suitable physical and chemical properties and characterization. In vitro antibacterial experiments showed that HA-AZI/Qe-M could effectively inhibit the growth of MRSA, inhibit and eliminate the biofilm formed by MRSA, and have an excellent therapeutic effect on intracellular bacterial infection. The results of RAW264.7 cells uptake and in vivo imaging showed that HA-AZI/Qe-M could increase the cellular uptake, target the infection site, and prolong the treatment time. The results of in vivo antibacterial infection experiments showed that HA-AZI/Qe-M was able to ameliorate the extent of thigh muscle infections in mice and reduce the expression of inflammatory factors.

Conclusion

HA-AZI/Qe-M is a novel and effective nano-drug delivery system that can target intracellular bacterial infection, and it is expected to be safely used for the treatment of MRSA infection.

Synthesis, Antimicrobial, Molecular Docking Against Bacterial and Fungal Proteins and In Silico Studies of Glucopyranoside Derivatives as Potent Antimicrobial Agents

Carbohydrate derivatives play a crucial roles in biochemical and medicinal research, especially in the fields of chemistry and biochemistry. From this perspective, the present study was designed to explore the synthesis of methyl α-D-glucopyranoside derivatives (1-8), focusing on their efficacy against bacterial and fungal inhibition. The structure of the synthesized compounds was ascertained using FTIR, 1H-NMR, 13C-NMR, mass and elemental analyses. Antimicrobial screening revealed strong antifungal properties, with compound 7 exhibiting minimum inhibitory concentrations (MICs) ranging from 16-32 μg/L and minimum bactericidal concentrations (MBCs) ranging from 64-128 μg/L. Incorporating decanoyl acyl groups at C-2 and C-3 of (7) significantly improved the efficacy against bacteria and fungi. Structure-activity relationship (SAR) analysis indicated that adding nonanoyl and decanoyl groups to the ribose moiety enhanced potency against both bacterial and fungal strains. Computational methods, including molecular docking, density functional theory (DFT), Petra, Osiris, Molinspiration (POM) evaluation, and molecular dynamics (MD) simulations, were used to assess the efficacy of these derivatives. Compounds 6 and 7, which presented nonanoyl and decanoyl substituents, demonstrated greater efficacy. In addition, DFT studies identified compound 8 as possessing ideal electronic properties. Molecular docking revealed that compound 8 exhibits exceptional binding affinities to bacterial proteins, conferring potent antibacterial and antifungal activities. In addition, pharmacokinetic optimization via POM analysis highlighted compounds 1 and 2 as promising bioavailable drugs with minimal toxicity. Molecular dynamics simulations confirmed the stability of the 2-S. aureus complex, revealing the therapeutic potential of compounds 2 and 8. Future experiments are required to validate their efficacy for pharmaceutical development. The integration of in vitro and in silico methods, including DFT anchoring dynamics and molecular dynamics simulations, provides a solid framework for the advancement of effective anti-infective drugs.

Preclinical pharmacokinetic studies and prediction of human PK profiles for Deg-AZM, a clinical-stage new transgelin agonist

Introduction

Deglycosylated azithromycin (Deg-AZM), a newly developed Class I drug with good therapeutic effects on slow transit constipation, is a small-molecule transgelin agonist that has been approved for clinical trials in 2024. The preclinical pharmacokinetic profile of Deg-AZM was investigated to support further development.

Methods

A LC-MS/MS method was established and validated to detected the concentration of Deg-AZM in various biological samples. In vivo tests such as pharmacokinetic studies in rats and dogs, tissue distribution studies in rats, and extraction studies in rats were conducted to investigated the preclinical pharmacokinetic behaviors of Deg-AZM comprehensively. The plasma protein rate of Deg-AZM was determined by rapid equilibrium dialysis method in vitro. The metabolic stability and metabolite profile of Deg-AZM was assessed using pooled mice, rats, dogs, monkeys and humans microsomes in vitro. The PK profiles of Deg-AZM in human was predicted based on physiologically based pharmacokinetic (PBPK) models.

Results

The plasma protein binding rates of Deg-AZM were lower in mice and rats, higher in dogs, and moderate in humans. The metabolic process of Deg-AZM was similar in rat and human liver microsomes. From Pharmacokinetic studies in rats and dogs, Deg-AZM was rapidly absorbed into the blood and then quickly eliminated. Plasma exposure of Deg-AZM was dose dependent with no accumulation after continuous gavage administration. In addition, there is no significant gender difference in the pharmacokinetic behavior of Deg-AZM. Deg-AZM was widely distributed in the tissues without obvious accumulation, and mainly excreted from the urinary excretion pathway. Furthermore, the pharmacokinetic profiles of Deg-AZM in humans showed dose dependency.

Conclusion

The pharmacokinetic profiles of Deg-AZM was fully explored, these results could provide valuable information to support the first-in-human dosage prediction and phase I clinical design.

Azithromycin regulates Mettl3-mediated NF-κB pathway to enhance M2 polarization of RAW264.7 macrophages and attenuate LPS-triggered cytotoxicity of MLE-12 alveolar cells

BACKGROUND

Azithromycin (AZM) has been proposed as a potential therapeutic drug in acute pulmonary injury due to its immunomodulatory and anti-inflammatory properties. However, its therapeutic mechanism remains not fully understood.

METHODS

LPS was used to stimulate MLE-12 cells and RAW264.7 macrophages. Analyses of viability and apoptosis were performed by CCK-8 assay and flow cytometry, respectively. Protein analysis was performed by immunoblotting, and mRNA expression was tested by quantitative PCR. The secretion levels of TNF-α and IL-6 were detected by ELISA. MDA, GSH, ROS and Fe2+ contents were analyzed using assay kits.

RESULTS

Administration of AZM or depletion of methyltransferase-like 3 (Mettl3) could attenuate LPS-triggered apoptosis, inflammation and ferroptosis in MLE-12 alveolar cells, as well as enhance M2 polarization of LPS-stimulated RAW264.7 macrophages. In LPS-exposed MLE-12 and RAW264.7 cells, AZM reduced Mettl3 protein expression and inactivated the NF-κB signaling through downregulation of Mettl3. Furthermore, Mettl3 restoration abated AZM-mediated anti-apoptosis, anti-inflammation and anti-ferroptosis effects in LPS-exposed MLE-12 cells and reversed AZM-mediated M2 polarization enhancement of LPS-exposed RAW264.7 macrophages.

CONCLUSION

Our study indicates that AZM can promote M2 polarization of LPS-exposed RAW264.7 macrophages and attenuate LPS-triggered injury of MLE-12 alveolar cells by inactivating the Mettl3-mediated NF-κB pathway.

Azithromycin removal using pine bark, oak ash and mussel shell

Adsorption is considered an interesting option for removing antibiotics from the environment because of its simple design, low cost, and potential efficiency. In this work we evaluated three by-products (pine bark, oak ash, and mussel shell) as bio-adsorbents for the antibiotic azithromycin (AZM). Furthermore, they were added at doses of 48 t ha-1 to four different soils, then comparing AZM removal for soils with and without bio-adsorbents. Batch-type experiments were used, adding AZM concentrations between 2.5 and 600 μmol L-1 to the different bio-adsorbents and soil + bio-adsorbent mixtures. Regarding the bio-adsorbents, oak ash showed the best adsorption scores (9600 μmol kg-1, meaning >80% retention), followed by pine bark (8280 μmol kg-1, 69%) and mussel shell (between 3000 and 6000 μmol kg-1, 25-50% retention). Adsorption data were adjusted to different models (Linear, Freundlich and Langmuir), showing that just mussel shell presented an acceptable fitting to the Freundlich equation, while pine bark and oak ash did not present a good adjustment to any of the three models. Regarding desorption, the values were always below the detection limit, indicating a rather irreversible adsorption of AZM onto these three by-products. Furthermore, the results showed that when the lowest concentrations of AZM were added to the not amended soils they adsorbed 100% of the antibiotic, whereas when the highest concentrations of AZM were spread, the adsorption decreased to 55%. However, when any of the three bio-adsorbents was added to the soils, AZM adsorption reached 100% for all the antibiotic concentrations used. Desorption was null in all cases for both soils with and without bio-adsorbents. These results, corresponding to an investigation carried out for the first time for the antibiotic AZM, can be seen as relevant in the search of low-cost alternative treatments to face environmental pollution caused by this emerging contaminant.

Antimicrobial Resistance in Gonorrhea

Antimicrobial resistance is a global public health emergency. The World Health Organization recently highlighted the growing number of new sexually transmitted infections such as gonorrhea, syphilis, and Chlamydia, which are resistant to common antibiotics. The phenomenon is also on the rise due to increasing intercontinental travel. Emerging antibiotic-resistant strains of gonorrhea are particularly associated with international spread from Southeast Asian travelers. Infection with Neisseria gonorrhoeae can cause a wide spectrum of associated diseases such as dermatitis, arthritis and septic arthritis, and pelvic inflammatory disease, and can even lead to serious health consequences for the individual. Natural infection confers no immunity, and vaccination is not available currently, although in several countries, it has been reported that the antimeningococcal vaccine may protect against gonorrhea. Implementing all necessary preventive measures is crucial, as well as appropriate and timely diagnostic methods and effective antimicrobial therapeutic treatments in the correct modalities to avoid the increase of forms of gonorrhea that are resistant to common antibiotics and difficult to eradicate.

A comprehensive review on targeting cluster of differentiation: An attractive strategy for inhibiting viruses through host proteins

Viral infections continue to pose a significant global public health threat. Targeting host proteins, such as cluster of differentiation (CD) macromolecules, may offer a promising alternative approach to developing antiviral treatments. CDs are cell-surface biological macromolecules mainly expressed on leukocytes that viruses can use to enter cells, thereby evading immune detection and promoting their replication. The manipulation of CDs by viruses may represent an effective and clever means of survival through the prolonged co-evolution of hosts and viruses. Targeting of CDs is anticipated to hinder the invasion of related viruses, modulate the body's immune system, and diminish the incidence of subsequent inflammation. They have become crucial for biomedical diagnosis, and some have been used as valuable tools for resisting viral infections. However, a summary of the structures and functions of CDs involved in viral infection is currently lacking. The development of drugs targeting these biological macromolecules is restricted both in terms of their availability and the number of compounds currently identified. This review provides a comprehensive analysis of the critical role of CD proteins in virus invasion and a list of relevant targeted antiviral agents, which will serve as a valuable reference for future research in this field.

Early-life antibiotic exposure promotes house dust mite-induced allergic airway inflammation by impacting gut microbiota and lung lipid metabolism

Asthma is a chronic inflammatory respiratory disease. Early-life antibiotic exposure is a unique risk factor for the incidence and severity of asthma later in life. Perturbations in microbial-metabolite-immune interaction caused by antibiotics are closely associated with the pathogenesis of allergy and asthma. We investigated the effect of early intervention with common oral antibiotics on later asthma exacerbations and found that different antibiotic exposures can amplify different types of immune responses induced by HDM. Cefixime (CFX) promoted a biased type 2 inflammation, azithromycin (AZM) enhanced Th17 immune response, and cefuroxime axetil (CFA) induced eosinophils recruitment. Moreover, early-life antibiotic exposure can have short- and long-term effects on the abundance, composition, and diversity of the gut microbiota. In the model of CFX-promoted type 2 airway inflammation, fecal metabolomics indicated abnormal lipid metabolism and T cell response. Lipidomic also suggested allergic airway inflammation amplified by CFX is closely associated with abnormal lipid metabolism in lung tissues. Moreover, abnormalities in lipid metabolism-related genes (LMRGs) were found to have cellular heterogeneity be associated with asthma severity by bioinformatics analysis.

A "toxic window" study on the hippocampal development of mice offspring exposed to azithromycin at different doses, courses, and time during pregnancy

BACKGROUND

Azithromycin, one of the new-generation macrolides, is an effective medicine for the treatment of mycoplasma infection during pregnancy. Epidemiological studies have reported adverse pregnancy outcomes with prenatal azithromycin exposure (PAzE). However, the effect of PAzE on fetal hippocampal development is unclear. This study aimed to explore the effects and potential mechanism of PAzE-induced fetal hippocampal development at different doses, courses, and time.

METHOD

Pregnant mice were administered azithromycin by gavage at different doses (50, 100 or 200 mg/kg.d), different courses (gestational day (GD)15-17 for three consecutive days, or GD17 once a day) and different time (GD10-12, GD15-17).

RESULTS

Compared with the control group, morphological development damage of the fetal hippocampus was observed in the PAzE group, with a dysbalance in neuronal proliferation and apoptosis, decreased expression of the neuronal-specific marker Snap25, NeuN, PSD95 and Map2, increased expression of the glial-specific marker Iba1, GFAP, and S-100β, and decreased expression of P2ry12. The PAzE-induced hippocampal developmental deficiency varied based on different doses, courses, and time, and the developmental toxicity was most significant in the late pregnancy, high dose, multi-course group (AZHT). The significant reduction of SOX2 and Wnt, which were related to regulation of neural progenitor cells (NPCs) proliferation in PAzE fetus compared with the control group indicated that the SOX2/Wnt signaling may be involved in PAzE-induced hippocampal developmental toxicity.

CONCLUSION

In this study, PAzE was associated with hippocampal developmental toxicity in a variety of nerve cells. Hippocampal developmental toxicity due to azithromycin was most significant in the late pregnancy, high-dose (equivalent to maximum clinical dose) and multi-course group (AZHT). The findings provide an experimental and theoretical foundation for guiding the sensible use of medications during pregnancy and effectively assessing the risk of fetal hippocampal developmental toxicity.

Effects of azithromycin exposure during pregnancy at different stages, doses and courses on testicular development in fetal mice

Azithromycin is a commonly used antibiotic during pregnancy, but some studies have suggested its potential developmental toxicity. Currently, the effects and mechanisms of prenatal azithromycin exposure (PAzE) on fetal testicular development are still unclear. The effects of prenatal exposure to the same drug on fetal testicular development could vary depending on different stages, doses, and courses. Hence, in this study, based on clinical medication characteristics, Kunming mice was administered intragastrically with azithromycin at different stages (mid-/late-pregnancy), doses (50, 100, 200 mg/kg·d), and courses (single-/multi-course). Fetal blood and testicular samples were collected on GD18 for relevant assessments. The results indicated that PAzE led to changes in fetal testicular morphology, reduced cell proliferation, increased apoptosis, and decreased expression of markers related to Leydig cells (Star), Sertoli cells (Wt1), and spermatogonia (Plzf). Further investigation revealed that the effects of PAzE on fetal testicular development were characterized by mid-pregnancy, high dose (clinical dose), and single course having more pronounced effects. Additionally, the TGFβ/Smad and Nrf2 signaling pathways may be involved in the changes in fetal testicular development induced by PAzE. In summary, this study confirmed that PAzE influences fetal testicular morphological development and multicellular function. It provided theoretical and experimental evidence for guiding the rational use of azithromycin during pregnancy and further exploring the mechanisms underlying its developmental toxicity on fetal testicles.

Factors Associated with Symptom Persistence in PANS: Part I-Access to Care

Objective: Pediatric acute-onset neuropsychiatric syndrome (PANS) presents with abrupt neuropsychiatric symptoms, often after an immunologic trigger. A 2017 survey of 698 subjects found diagnostic delays to be associated with recurrences, suggesting that timely care impacts course. This secondary analysis explores the impact of barriers to care on symptom persistence. Methods: A 146-question online survey gathered history, symptomatology, intervention, and outcome data from subjects with PANS. Multivariate analyses examined associations between symptom persistence over the entire reported disease course, measured as % days symptom-free over reporting periods averaging approximately 4 years, and access-to-care history, reflected in availability of medical expertise and affordability of care. The impacts of time from symptom onset to treatment and effectiveness of initial antibiotics were also examined. Results: Among the 646 subjects analyzed, greater symptom persistence was associated with longer intervals between symptom onset and treatment (F = 4.43, p = 0.002). Thirty-four percent of subjects with the least symptom persistence (>75% symptom-free days), versus 13% of those with the most (symptoms every day), had been diagnosed by the first practitioner seen (likelihood ratio [L-R] χ2 = 36.55, p < 0.0001, for comparison across all groups). Diagnosis and treatment had not been impeded by lack of access to expertise for 52% of subjects with the least persistent symptoms, versus 22% of those with the most (L-R χ2 = 22.47, p < 0.0001). Affordability had not impacted diagnosis and treatment for 76% of subjects with the least persistent symptoms, versus 42% of those with the most (L-R χ2 = 27.83, p < 0.0001). The subjects whose PANS symptoms resolved with antibiotic treatment of the inciting infection experienced less symptom persistence than others (χ2 = 23.27, p = 0.0001). More persistently symptomatic subjects were more likely to have discontinued intravenous immunoglobulin (IVIG) treatment for access-to-care reasons. Conclusions: Unimpeded access to care for PANS is associated with more symptom-free days over reporting periods averaging approximately 4 years. Difficulty reaching expert providers, missed opportunities for diagnoses, and financial limitations may worsen outcomes. Practitioners, particularly primary providers, should adhere to published diagnostic and treatment guidelines promptly upon presentation.

Profile and resistance levels of 136 integron resistance genes

Integrons have played a major role in the rise and spread of multidrug resistance in Gram-negative pathogens and are nowadays commonplace among clinical isolates. These platforms capture, stockpile, and modulate the expression of more than 170 antimicrobial resistance cassettes (ARCs) against most clinically-relevant antibiotics. Despite their importance, our knowledge on their profile and resistance levels is patchy, because data is scattered in the literature, often reported in different genetic backgrounds and sometimes extrapolated from sequence similarity alone. Here we have generated a collection of 136 ARCs against 8 antibiotic families and disinfectants. Cassettes are cloned in a vector designed to mimic the genetic environment of a class 1 integron, and transformed in Escherichia coli. We have measured the minimal inhibitory concentration (MIC) to the most relevant molecules from each antibiotic family. With more than 500 MIC values, we provide an exhaustive and comparable quantitation of resistance conferred by ARCs. Our data confirm known resistance trends and profiles while revealing important differences among closely related genes. We have also detected genes that do not confer the expected resistance, to the point of challenging the role of the whole family of qac genes in resistance against disinfectants. Our work provides a detailed characterization of integron resistance genes at-a-glance.

Qualitative and Quantitative Analysis of Azithromycin as Solid Dosage by Raman Spectroscopy

Active pharmaceutical ingredients (APIs) and excipients are main drug constituents that ought to be identified qualitatively and quantitatively. Raman spectroscopy is aimed to be an efficient technique for pharmaceutical analysis in solid dosage forms. This technique can successfully be used in terms of qualitative and quantitative analysis of pharmaceutical drugs, their APIs, and excipients. In the proposed research, Raman spectroscopy has been employed to quantify Azithromycin based on its distinctive Raman spectral features by using commercially prepared formulations with altered API concentrations and excipients as well. Along with Raman spectroscopy, principal component analysis and partial least squares regression (PLSR), two multivariate data analysis techniques have been used for the identification and quantification of the API. For PLSR, goodness of fit of the model (R2) was found to be 0.99, whereas root mean square error of calibration was 0.46 and root mean square error of prediction was 2.42, which represent the performance of the model. This study highlights the efficiency of Raman spectroscopy in the field of pharmaceutics by preparing pharmaceutical formulations of any drug to quantify their API and excipients to compensate for the commercially prepared concentrations.

Impact of COVID-19 pandemic on profiles of antibiotic-resistant genes and bacteria in hospital wastewater

The COVID-19 pandemic has severely affected healthcare worldwide and has led to the excessive use of disinfectants and antimicrobial agents. However, the impact of excessive disinfection measures and specific medication prescriptions on the development and dissemination of bacterial drug resistance during the pandemic remains unclear. This study investigated the influence of the pandemic on the composition of antibiotics, antibiotic resistance genes (ARGs), and pathogenic communities in hospital wastewater using ultra-performance liquid chromatography-tandem mass spectrometry and metagenome sequencing. The overall level of antibiotics decreased after the COVID-19 outbreak, whereas the abundance of various ARGs increased in hospital wastewater. After COVID-19 outbreak, blaOXA, sul2, tetX, and qnrS had higher concentrations in winter than in summer. Seasonal factors and the COVID-19 pandemic have affected the microbial structure in wastewater, especially of Klebsiella, Escherichia, Aeromonas, and Acinetobacter. Further analysis revealed the co-existence of qnrS, blaNDM, and blaKPC during the pandemic. Various ARGs significantly correlated with mobile genetic elements, implying their potential mobility. A network analysis revealed that many pathogenic bacteria (Klebsiella, Escherichia, and Vibrio) were correlated with ARGs, indicating the existence of multi-drug resistant pathogens. Although the calculated resistome risk score did not change significantly, our results suggest that the COVID-19 pandemic shifted the composition of residual antibiotics and ARGs in hospital wastewater and contributed to the dissemination of bacterial drug resistance.

Azithromycin inhibits glioblastoma angiogenesis in mice via inducing mitochondrial dysfunction and oxidative stress

The poor outcomes in glioblastoma (GBM) necessitate new treatments. As GBM is highly vascularized and its growth is largely dependent on angiogenesis, angiogenesis inhibitors have been hotly evaluated in clinical trials for GBM treatment for the last decade. In line with these efforts, our work reveals that azithromycin, a clinically available antibiotic, is a novel angiogenesis inhibitor. Azithromycin inhibits vessel structure formation on Matrigel of GBM-derived endothelial cell (ECs) and other types of ECs. Time course analysis shows that azithromycin interferes with the early stage of angiogenesis. Azithromycin also inhibits GBM-derived EC adhesion, growth and survival but not migration. The transgenic zebrafish Tg (fli1a: EGFP) model clearly shows that azithromycin inhibits angiogenesis in vivo. Of note, azithromycin at non-toxic dose inhibits GBM growth in mice and increases overall survival, and furthermore, this is associated with angiogenesis inhibition. Mechanism studies show that azithromycin decreases mitochondrial respiration by suppressing the activity of multiple complexes, leading to ATP reduction, oxidative stress and damage. In addition, oxidative stress induced by azithromycin is through thiol redox-mediated pathways. Our work demonstrates the anti-angiogenic activity of azithromycin via inducing mitochondrial dysfunction and oxidative stress. Our pre-clinical evidence provides a rationale for initiating clinical trials using azithromycin in combination with standard-of-care drugs for GBM patients.

In vitro synergy screens of FDA-approved drugs reveal novel zidovudine- and azithromycin-based combinations with last-line antibiotics against Klebsiella pneumoniae

Treatment of infections caused by multi-drug resistant (MDR) enterobacteria remains challenging due to the limited therapeutic options available. Drug repurposing could accelerate the development of new urgently needed successful interventions. This work aimed to identify and characterise novel drug combinations against Klebsiella pneumoniae based on the concepts of synergy and drug repurposing. We first performed a semi-qualitative high-throughput synergy screen (sHTSS) with tigecycline, colistin and fosfomycin (last-line antibiotics against MDR Enterobacteriaceae) against a FDA-library containing 1430 clinically approved drugs; a total of 109 compounds potentiated any of the last-line antibiotics. Selected hits were further validated by secondary checkerboard (CBA) and time-kill (TKA) assays, obtaining 15.09% and 65.85% confirmation rates, respectively. Accordingly, TKA were used for synergy classification based on determination of bactericidal activities at 8, 24 and 48 h, selecting 27 combinations against K. pneumoniae. Among them, zidovudine or azithromycin combinations with last-line antibiotics were further evaluated by TKA against a panel of 12 MDR/XDR K. pneumoniae strains, and their activities confronted with those clinical combinations currently used for MDR enterobacteria treatment; these combinations showed better bactericidal activities than usual treatments without added cytotoxicity. Our studies show that sHTSS paired to TKA are powerful tools for the identification and characterisation of novel synergistic drug combinations against K. pneumoniae. Further pre-clinical studies might support the translational potential of zidovudine- and azithromycin-based combinations for the treatment of these infections.

Additive Effects of Cyclic Peptide [R4W4] When Added Alongside Azithromycin and Rifampicin against Mycobacterium avium Infection

Mycobacterium avium (M. avium), a type of nontuberculous mycobacteria (NTM), poses a risk for pulmonary infections and disseminated infections in immunocompromised individuals. Conventional treatment consists of a 12-month regimen of the first-line antibiotics rifampicin and azithromycin. However, the treatment duration and low antibiotic tolerability present challenges in the treatment of M. avium infection. Furthermore, the emergence of multidrug-resistant mycobacterium strains prompts a need for novel treatments against M. avium infection. This study aims to test the efficacy of a novel antimicrobial peptide, cyclic [R4W4], alongside the first-line antibiotics azithromycin and rifampicin in reducing M. avium survival. Colony-forming unit (CFU) counts were assessed after treating M. avium cultures with varying concentrations of cyclic [R4W4] alone or in conjunction with azithromycin or rifampicin 3 h and 4 days post-treatment. M. avium growth was significantly reduced 4 days after cyclic [R4W4] single treatment. Additionally, cyclic [R4W4]-azithromycin and cyclic [R4W4]-rifampicin combination treatments at specific concentrations significantly reduced M. avium survival 3 h and 4 days post-treatment compared with single antibiotic treatment alone. These findings demonstrate cyclic [R4W4] as a potent treatment method against M. avium and provide insight into novel therapeutic approaches against mycobacterium infections.

Antibiotic resistance profile of Helicobacter pylori to 14 antibiotics: a multicenter study in Fujian, China

Background and aim

Efficacy of Helicobacter pylori (H. pylori) eradication is related to the local antimicrobial resistance epidemiology. We aimed to investigate the antibiotic resistance of H. pylori in Fujian, China.

Methods

H. pylori-infected patients in four centers were enrolled in the study from Oct 2019 to Jan 2022. The bacteria were isolated, cultured and identified from the biopsy of patients' gastric mucosa samples. Antimicrobial susceptibility testing was performed by a modified broth microdilution method for H. pylori to seven guideline-recommended antibiotics and seven potential choices for H. pylori eradication.

Results

A total of 205 H. pylori strains were isolated. The resistance rates of amoxicillin (AMX), amoxicillin and clavulanate potassium (AMC), cefixime (CFM), gentamicin (GEN), tetracycline (TET), doxycycline (DOX), azithromycin (AZM), clarithromycin (CLR), levofloxacin (LVFX), sparfloxacin (SPFX), metronidazole (MTZ), tinidazole (TID), rifampicin (RFP) and furazolidone (FZD) were 11.22%, 12.20%, 7.32%, 12.20%, 4.88%, 4.39%, 44.39%, 43.90%, 30.24%, 21.46%, 40.98%, 45.85%, 5.37% and 10.24%, respectively. The rates of pan-sensitivity, single, double, triple and multiple resistance for seven guideline-recommended antibiotics were 32.68%, 30.24%, 13.17%, 7.76%, and 14.15%, respectively. The main double-resistance patterns were CLR+MTZ (10/205, 5%) and CLR+LVFX (9/205, 4%). The main triple-resistance pattern was CLR+MTZ+ LVFX (15/205, 7%).

Conclusions

In Fujian, the prevalence of H. pylori resistance to AZM, CLR, LVFX, SPFX, MTZ, and TID was high, whereas that to AMX, AMC, GEN, CFM, TET, DOX, RFP and FZD was relatively low. CFM and DOX are promising new choices for H. pylori eradication.

Molecular interaction of lysozyme with therapeutic drug azithromycin: Effect of sodium dodecyl sulfate on binding profile

This paper describes an inclusive biophysical study elucidating the interaction of therapeutic drug azithromycin (Azith) with hen egg white lysozyme (HEWL). Spectroscopic and computational tools have been employed to study the interaction of Azith with HEWL at pH 7.4. The fluorescence quenching constant values (Ksv) exhibited a decrease with the increase in temperature which revealed the occurrence of static quenching mechanism between Azith and HEWL. The thermodynamic data demonstrated that hydrophobic interactions were predominantly involved in the Azith-HEWL interaction. The negative value of standard Gibbs free energy (ΔG°) stated that the Azith-HEWL complex formed via spontaneous molecular interactions. The effect of sodium dodecyl sulfate (SDS) surfactant monomers on the binding propensity of Azith with HEWL was insignificant at lower concentrations however the binding significantly decreased at increased concentrations of the former. Far-UV CD data revealed alteration in the secondary structure of HEWL in the presence of Azith and the overall HEWL conformation changed. Molecular docking results revealed that the binding of Azith with HEWL takes place through hydrophobic interactions and hydrogen bonds.

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.

The comparative analysis of gastrointestinal toxicity of azithromycin and 3'-decladinosyl azithromycin on zebrafish larvae

The most commonly reported side effect of azithromycin is gastrointestinal (GI) disorders, and the main acid degradation product is 3'-Decladinosyl azithromycin (impurity J). We aimed to compare the GI toxicity of azithromycin and impurity J on zebrafish larvae and investigate the mechanism causing the differential GI toxicity. Results of our study showed that the GI toxicity induced by impurity J was higher than that of azithromycin in zebrafish larvae, and the effects of impurity J on transcription in the digestive system of zebrafish larvae were significantly stronger than those of azithromycin. Additionally, impurity J exerts stronger cytotoxic effects on GES-1 cells than azithromycin. Simultaneously, impurity J significantly increased ghsrb levels in the zebrafish intestinal tract and ghsr levels in human GES-1 cells compared to azithromycin, and ghsr overexpression significantly reduced cell viability, indicating that GI toxicity induced by azithromycin and impurity J may be correlated with ghsr overexpression induced by the two compounds. Meanwhile, molecular docking analysis showed that the highest -CDOCKER interaction energy scores with the zebrafish GHSRb or human GHSR protein might reflect the effect of azithromycin and impurity J on the expression of zebrafish ghsrb or human ghsr. Thus, our results suggest that impurity J has higher GI toxicity than azithromycin due to its greater ability to elevate ghsrb expression in zebrafish intestinal tract.

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.

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.

Antibacterial drugs and cyclodextrin inclusion complexes: a patent review

INTRODUCTION

Bacterial antibiotic resistance occurs when bacteria mutate and escape the effect of antibiotics, which makes the antibiotics no longer effective in treating infections. New solutions for bacterial infections are a persistent need including the identification of drugs with better pharmacological profiles, more potent, and safer. Cyclodextrins inclusion complexes have been able to improve the physicochemical and pharmacological properties of the formulation molecules, resulting in new alternatives with better efficacy.

AREAS COVERED

The patents analyzed in the review used treatments based on antibiotics already on the market, natural products, and synthesized molecules composed of the formulation with cyclodextrins. The combination between cyclodextrin and nanostructures also were presented in the patents review process. Moreover, inclusion complexes have been an alternative in developing treatment mainly in China by the pharmaceutical industries in several countries such as Germany, Hungary, the United States of America, Japan and China.

EXPERT OPINION

This review is broad and complete since it considers the first patent involving cyclodextrins and antibacterial drugs. Therefore, the various inclusion complexes and antibacterial drugs alternatives presented in this review offer therapeutic options to fight bacterial infections. If shown to be effective, these drugs may be extremely important in the current clinical practice.

Current Insights and Molecular Docking Studies of the Drugs under Clinical Trial as RdRp Inhibitors in COVID-19 Treatment

Study Background & Objective: After the influenza pandemic (1918), COVID-19 was declared a Vth pandemic by the WHO in 2020. SARS-CoV-2 is an RNA-enveloped single-stranded virus. Based on the structure and life cycle, Protease (3CLpro), RdRp, ACE2, IL-6, and TMPRSS2 are the major targets for drug development against COVID-19. Pre-existing several drugs (FDA-approved) are used to inhibit the above targets in different diseases. In coronavirus treatment, these drugs are also in different clinical trial stages. Remdesivir (RdRp inhibitor) is the only FDA-approved medicine for coronavirus treatment. In the present study, by using the drug repurposing strategy, 70 preexisting clinical or under clinical trial molecules were used in scrutiny for RdRp inhibitor potent molecules in coronavirus treatment being surveyed via docking studies. Molecular simulation studies further confirmed the binding mechanism and stability of the most potent compounds.

MATERIAL AND METHODS

Docking studies were performed using the Maestro 12.9 module of Schrodinger software over 70 molecules with RdRp as the target and remdesivir as the standard drug and further confirmed by simulation studies.

RESULTS

The docking studies showed that many HIV protease inhibitors demonstrated remarkable binding interactions with the target RdRp. Protease inhibitors such as lopinavir and ritonavir are effective. Along with these, AT-527, ledipasvir, bicalutamide, and cobicistat showed improved docking scores. RMSD and RMSF were further analyzed for potent ledipasvir and ritonavir by simulation studies and were identified as potential candidates for corona disease.

CONCLUSION

The drug repurposing approach provides a new avenue in COVID-19 treatment.

Alginate oligosaccharide ameliorates azithromycin-induced gut microbiota disorder via Bacteroides acidifaciens-FAHFAs and Bacteroides-TCA cycle axes

Alginate oligosaccharide is a kind of prebiotic with broad application prospects. However, little attention is paid to the recovery effect of alginate oligosaccharide on disordered intestinal microecology caused by azithromycin. Therefore, we evaluated the regulatory effect of alginate oligosaccharide and its compound on azithromycin-disturbed gut microbiota in mice via microbiome-metabolomics analysis. The gut microbiota analysis revealed that alginate oligosaccharide and its compound significantly increased the richness and diversity of the gut microbiota which were reduced by azithromycin, with an obvious enrichment of beneficial bacteria such as the Akkermansia genus and Bacteroides acidifaciens, and a remarkable decrease of pathogenic bacteria such as the Staphylococcus genus, which indicated its impact on the gut microbiota dysbiosis. Additionally, the effect of the alginate oligosaccharide compound on regulating the gut microbiota disorder is more significant than that of alginate oligosaccharide. The favorable effects of alginate oligosaccharide were confirmed by beneficial alterations in metabolic effector molecules, which indicated that alginate oligosaccharide and its compound improved metabolic homeostasis via the Bacteroides acidifaciens-fatty acid esters of hydroxy fatty acids (FAHFAs) axis and increasing the levels of the intermediate products of the tricarboxylic acid cycle (TCA cycle), such as citric acid, fumaric acid and α-ketoglutaric acid. Spearman correlation analysis showed that the contents of these three metabolites were also positively related to Bacteroides acidifaciens and Bacteroides sartorii populations, suggesting the potential regulatory role of the Bacteroides genus in energy balance through the TCA cycle. This study may provide an innovative dietary strategy for the regulation of intestinal microecological disorders caused by antibiotics, and reveal the prospect of alginate oligosaccharide as an intestinal microecological regulator.

Increased similarity of aquatic bacterial communities of different origin after antibiotic disturbance

Stochastic or deterministic processes control the bacterial community assembly in waters and their understanding is a fundamental question to correctly manage aquatic environments exposed to the release of antibiotics from anthropogenic sources. It has been suggested that microdiversity (i.e. the rare biosphere) convers freshwater communities with stability, meaning that previously rare taxa bloom when the community is disturbed. Since there might be a seed bank of similar, but not abundant, bacterial taxa in different waters, we tested whether a disturbance by an antibiotic cocktail would increase similarity in bacterial communities from different freshwater systems (a wastewater effluent and two lakes). In a continuous culture set-up in chemostats, we show that disturbance with antibiotics causes communities from different environments to become more similar. Once the antibiotic pressure is released the communities tend to become more dissimilar again. This shows that there is a similar shift in community composition even in waters from very different origins when they are disturbed by antibiotics, even at low concentrations. Antibiotics impact the bacterial communities at the cell and the community level, independently by the original degree of anthropogenic stress they are adapted to, altering the original phenotypes, genotypes, and the relations between bacteria.

Review of Analytical Methods for Evaluating Azithromycin in the Context of Green Analytical Chemistry

BACKGROUND

Azithromycin (AZT) is an antimicrobial available in different pharmaceutical forms and many people can have access to this medicine. Therefore, the existence of adequate and reliable analytical methods for evaluating the quality of AZT and AZT-based products is essential.

OBJECTIVE/METHODS

The purpose of this review is to discuss the analytical methods for evaluating AZT present in the literature and official compendia in the context of Green Analytical Chemistry (GAC).

RESULTS

Among the methods found in the literature for evaluating AZT, the most used method is HPLC (62%) followed by TLC (14%) and the microbiological method by agar diffusion (14%). Even pharmacopoeias recommend the analysis of AZT by HPLC or agar diffusion. Acetonitrile and methanol account for 35% of the most used solvents in the analyses, followed by buffer.

CONCLUSION

AZT lacks analytical methods in the context of GAC. Both physical-chemical and microbiological methods can contemplate the environmentally friendly way to analyze AZT and AZT-based products, depending only on the chosen conditions. Ethanol, purified water, acetic acid instead of methanol, acetonitrile, buffer, formic acid in the physical-chemical methods are excellent alternatives. However, in the microbiological method, turbidimetry is a great option instead of agar diffusion.

Azithromycin Mitigates Cisplatin-Induced Lung Oxidative Stress, Inflammation and Necroptosis by Upregulating SIRT1, PPARγ, and Nrf2/HO-1 Signaling

Acute lung injury (ALI) is one of the adverse effects of the antineoplastic agent cisplatin (CIS). Oxidative stress, inflammation, and necroptosis are linked to the emergence of lung injury in various disorders. This study evaluated the effect of the macrolide antibiotic azithromycin (AZM) on oxidative stress, inflammatory response, and necroptosis in the lungs of CIS-administered rats, pinpointing the involvement of PPARγ, SIRT1, and Nrf2/HO-1 signaling. The rats received AZM for 10 days and a single dose of CIS on the 7th day. CIS provoked bronchial and alveolar injury along with increased levels of ROS, MDA, NO, MPO, NF-κB p65, TNF-α, and IL-1β, and decreased levels of GSH, SOD, GST, and IL-10, denoting oxidative and inflammatory responses. The necroptosis-related proteins RIP1, RIP3, MLKL, and caspase-8 were upregulated in CIS-treated rats. AZM effectively prevented lung tissue injury, ameliorated oxidative stress and NF-κB p65 and pro-inflammatory markers levels, boosted antioxidants and IL-10, and downregulated necroptosis-related proteins in CIS-administered rats. AZM decreased the concentration of Ang II and increased those of Ang (1-7), cytoglobin, PPARγ, SIRT1, Nrf2, and HO-1 in the lungs of CIS-treated rats. In conclusion, AZM attenuated the lung injury provoked by CIS in rats through the suppression of inflammation, oxidative stress, and necroptosis. The protective effect of AZM was associated with the upregulation of Nrf2/HO-1 signaling, cytoglobin, PPARγ, and SIRT1.

Solvothermal synthesis of nitrogen-doped carbon quantum dots for the sensitive detection of azithromycin

Carbon quantum dots are widely used in various drug detection applications because of their excellent photoluminescence properties. However, there are few reports about the detection of macrolide antibiotics. In this work, blue emitting nitrogen-doped carbon quantum dots (N-CQDs) were synthesized by using a hydrothermal method, which exhibit the most prominent emission band at 464 nm at an excitation wavelength of 414 nm. And it was found that Cu²⁺alone or the macrolide antibiotic azithromycin had no significant effect on the fluorescence intensity of N-CQDs. Still, when the two were mixed, they quenched the fluorescence of N-CQDs. Based on this, a fluorescence assay for azithromycin were developed. The fluorescence of the mixture of N-CQDs and Cu²⁺showed good linearity with azithromycin (0.52-42.2μM) with a low detection limit of 0.52μM.

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.

Les misérables: a Parallel Between Antimicrobial Resistance and COVID-19 in Underdeveloped and Developing Countries

Purpose of Review

The COVID-19 pandemic has been responsible for more than 6.3 million deaths worldwide. During the pandemic, the indiscriminate use of antibiotics has increased, contributing to the spread of multidrug-resistant bacteria. In this review, we aim to determine the spread and impact of antibiotic treatments in patients with COVID-19, focusing on underdeveloped and developing countries.

Recent Findings

Meta-analysis revealed that bacterial co-infections and secondary infections are relatively rare in COVID-19 patients, corresponding to less than 20% of hospitalized patients. Even so, most of these patients have received antibiotic treatments.

Summary

This review discusses how the COVID-19 pandemic could increase the emergence of multidrug-resistant strains to currently available antibiotics. Initially, we discussed the spread and impact of multidrug resistance of ESKAPE pathogens associated with nosocomial infections and analyzed their risk of secondary infections in patients with COVID-19. Then we highlight three factors related to the spread of resistant bacteria during the current pandemic: overprescription of antibiotics followed by self-medication. Finally, we discussed the lack of availability of diagnostic tests to discriminate the etiologic agent of a disease. All these factors lead to inappropriate use of antibiotics and, therefore, to an increase in the prevalence of resistance, which can have devastating consequences shortly. The data compiled in this study underscore the importance of epidemiological surveillance of hospital isolates to provide new strategies for preventing and controlling infections caused by multidrug-resistant bacteria. In addition, the bibliographic research also highlights the need for an improvement in antibiotic prescribing in the health system.

Pharmacokinetics and Bioequivalence of 2 Azithromycin Tablet Formulations: A Randomized, Open-Label, 2-Stage Crossover Study in Healthy Volunteers

The current study aimed to assess the bioequivalence of a new branded azithromycin with the reference formulation. An open-label, randomized, 2-stage, crossover study design was implemented involving 77 healthy volunteers under fasting conditions. Each volunteer received a single dose of 250-mg azithromycin tablets test and reference formulations separated by a 21-day washout period. Twenty-two samples were collected at pre-dose and until 72 hours post-dose. Azithromycin concentrations were analyzed using a high-performance liquid chromatography-mass spectrometry validated method following a solid-phase plasma extraction. Noncompartmental analysis was carried out to estimate the pharmacokinetic parameters, which were compared between the test and reference products using a multivariate analysis of variance. The difference between C_max and AUC_0-72 of the test and reference formulation was not significant. The 94.1% confidence intervals of ln-transformed C_max and AUC_0-72 of azithromycin were within the bioequivalence acceptance limits of 80%-125%, therefore it can be concluded that the tested formulation is bioequivalent to the reference formulation.

Clinical Efficacy and In Vitro Drug Sensitivity Test Results of Azithromycin Combined With Other Antimicrobial Therapies in the Treatment of MDR P. aeruginosa Ventilator-Associated Pneumonia

Objective: The aim of the research was to study the effect of azithromycin (AZM) in the treatment of MDR P. aeruginosa VAP combined with other antimicrobial therapies.

Methods: The clinical outcomes were retrospectively collected and analyzed to elucidate the efficacy of different combinations involving azithromycin in the treatment of MDR-PA VAP. The minimal inhibitory concentration (MIC) of five drugs was measured by the agar dilution method against 27 isolates of MDR-PA, alone or in combination.

Results: The incidence of VAP has increased approximately to 10.4% (961/9245) in 5 years and 18.4% (177/961) caused by P. aeruginosa ranking fourth. A total of 151 cases of MDR P. aeruginosa were included in the clinical retrospective study. Clinical efficacy results are as follows: meropenem + azithromycin (MEM + AZM) was 69.2% (9/13), cefoperazone/sulbactam + azithromycin (SCF + AZM) was 60% (6/10), and the combination of three drugs containing AZM was 69.2% (9/13). The curative effect of meropenem + amikacin (MEM + AMK) was better than that of the meropenem + levofloxacin (MEM + LEV) group, p = 0.029 (p < 0.05). The curative effect of cefoperazone/sulbactam + amikacin (SCF + AMK) was better than that of the cefoperazone/sulbactam + levofloxacin (SCF + LEV) group, p = 0.025 (p < 0.05). There was no significant difference between combinations of two or three drugs containing AZM, p > 0.05 (p = 0.806). From the MIC results, the AMK single drug was already very sensitive to the selected strains. When MEM or SCF was combined with AZM, the sensitivity of them to strains can be significantly increased. When combined with MEM and AZM, the MIC₅₀ and MIC₉₀ of MEM decreased to 1 and 2 ug/mL from 8 to 32 ug/mL. When combined with SCF + AZM, the MIC₅₀ of SCF decreased to 16 ug/mL, and the curve shifted obviously. However, for the combination of SCF + LEV + AZM, MIC₅₀ and MIC₉₀ could not achieve substantive changes. From the FIC index results, the main actions of MEM + AZM were additive effects, accounting for 72%; for the combination of SCF + AZM, the additive effect was 40%. The combination of AMK or LEV with AZM mainly showed unrelated effects, and the combination of three drugs could not improve the positive correlation between LEV and AZM.

Conclusion: AZM may increase the effect of MEM or SCF against MDR P. aeruginosa VAP. Based on MEM or SCF combined with AMK or AZM, we can achieve a good effect in the treatment of MDR P. aeruginosa VAP.

Azithromycin through the Lens of the COVID-19 Treatment

Azithromycin has become famous in the last two years, not for its main antimicrobial effect, but for its potential use as a therapeutic agent for COVID-19 infection. Initially, there were some promising results that supported its use, but it has become clear that scientific results are insufficient to support such a positive assessment. In this review we will present all the literature data concerning the activity of azithromycin as an antimicrobial, an anti-inflammatory, or an antivirus agent. Our aim is to conclude whether its selection should remain as a valuable antivirus agent or if its use simply has an indirect therapeutic contribution due to its antimicrobial and/or immunomodulatory activity, and therefore, if its further use for COVID-19 treatment should be interrupted. This halt will prevent further antibiotic resistance expansion and will keep azithromycin as a valuable anti-infective therapeutic agent.

A determination of pan-pathogen antimicrobials?

While antimicrobial drug development has historically mitigated infectious diseases that are known, COVID-19 revealed a dearth of 'in-advance' therapeutics suitable for infections by pathogens that have not yet emerged. Such drugs must exhibit a property that is antithetical to the classical paradigm of antimicrobial development: the ability to treat infections by any pathogen. Characterisation of such 'pan-pathogen' antimicrobials requires consolidation of drug repositioning studies, a new and growing field of drug discovery. In this review, a previously-established system for evaluating repositioning studies is used to highlight 4 therapeutics which exhibit pan-pathogen properties, namely azithromycin, ivermectin, niclosamide, and nitazoxanide. Recognition of the pan-pathogen nature of these antimicrobials is the cornerstone of a novel paradigm of antimicrobial development that is not only anticipatory of pandemics and bioterrorist attacks, but cognisant of conserved anti-infective mechanisms within the host-pathogen interactome which are only now beginning to emerge. Ultimately, the discovery of pan-pathogen antimicrobials is concomitantly the discovery of a new class of antivirals, and begets significant implications for pandemic preparedness research in a world after COVID-19.