Azithromycin

Terminal complement complexes with or without C9 potentiate antimicrobial activity against Neisseria gonorrhoeae

The complement cascade is a front-line defense against pathogens. Complement activation generates the membrane attack complex (MAC), a 10-11 nm diameter pore formed by complement proteins C5b through C8 and polymerized C9. The MAC embeds within the outer membrane of Gram-negative bacteria and displays bactericidal activity. In the absence of C9, C5b-C8 complexes can form 2-4 nm pores on membranes, but their relevance to microbial control is poorly understood. Deficiencies in terminal complement components uniquely predispose individuals to infections by pathogenic Neisseria, including N. gonorrhoeae (Gc). Increasing antibiotic resistance in Gc makes new therapeutic strategies a priority. Here, we demonstrate that MAC formed by complement activity in human serum disrupts the Gc outer and inner membranes, potentiating the activity of antimicrobials against Gc and re-sensitizing multidrug-resistant Gc to antibiotics. C9-depleted serum also exerts bactericidal activity against Gc and, unlike other Gram-negative bacteria, disrupts both the outer and inner membranes. C5b-C8 complex formation potentiates Gc sensitivity to azithromycin and ceftriaxone, but not lysozyme or nisin. These findings expand our mechanistic understanding of complement lytic activity, suggest a size limitation for terminal complement-mediated enhancement of antimicrobials against Gc, and suggest that complement manipulation can be used to combat drug-resistant gonorrhea.

IMPORTANCE

The complement cascade is a front-line arm of the innate immune system against pathogens. Complement activation results in membrane attack complex (MAC) pores forming on the outer membrane of Gram-negative bacteria, resulting in bacterial death. Individuals who cannot generate MAC are specifically susceptible to infection by pathogenic Neisseria species including N. gonorrhoeae (Gc). High rates of gonorrhea, its complications like infertility, and high-frequency resistance to multiple antibiotics make it important to identify new approaches to combat Gc. Beyond direct anti-Gc activity, we found that the MAC increases the ability of antibiotics and antimicrobial proteins to kill Gc and re-sensitizes multidrug-resistant bacteria to antibiotics. The most terminal component, C9, is needed to potentiate the anti-Gc activity of lysozyme and nisin, but azithromycin and ceftriaxone activity is potentiated regardless of C9. These findings highlight the unique effects of MAC on Gc and suggest novel translational avenues to combat drug-resistant gonorrhea.

Detection, characterization, and antibiotic resistance profiling of multidrug-resistant bacteria isolated from circulating currency in the Northeastern region of Bangladesh

Objectives

The study aims to investigate the prevalence of multidrug resistant bacteria on paper and coin currency obtained from various occupational groups in Bangladesh and to identify the bacterial species present. The research further seeks to evaluate the antibiotic resistance patterns of the identified bacterial isolates.

Methods

84 paper currency notes and 56 coins were collected from seven different sources. Bacterial contamination was assessed using standard bacteriological and biochemical tests to identify and characterize the bacteria. Antibiotic susceptibility of the isolated strains was evaluated using an antibiogram study.

Results

A total of 368 bacterial isolates were detected across the sampled currency, with 99% of the currency samples contaminated by bacteria. Paper currency exhibited a higher prevalence of contamination compared to coins. Gram-staining revealed 20% Gram-positive and 80% Gram-negative bacteria on notes, compared to 38% Gram-positive and 62% Gram-negative bacteria on coins. Bacterial contamination was most frequent in samples from fish sellers, followed by poultry sellers, fruit sellers, and restaurants. The most commonly identified bacteria were Salmonella typhimurium, Staphylococcus aureus, Escherichia coli, and Klebsiella aerogenes. Antibiotic resistance testing revealed that all isolates were 100% resistant to amoxicillin, ampicillin, and penicillin G, while showing 100% sensitivity to azithromycin and gentamycin. Notably, 70.8% of the isolates were resistant to tetracycline, and 75% showed resistance to cefotaxime.

Conclusions

The widespread contamination of currency in Bangladesh with multidrug-resistant bacteria underscore the growing concern about antibiotic resistance. Preventative measures are essential to reduce cross-contamination between currency and food.

Terminal complement complexes with or without C9 potentiate antimicrobial activity against Neisseria gonorrhoeae

The complement cascade is a front-line defense against pathogens. Complement activation generates the membrane attack complex (MAC), a 10-11 nm diameter pore formed by complement proteins C5b through C8 and polymerized C9. The MAC embeds within the outer membrane of Gram-negative bacteria and displays bactericidal activity. In the absence of C9, C5b-C8 complexes can form 2-4 nm pores on membranes, but their relevance to microbial control is poorly understood. Deficiencies in terminal complement components uniquely predispose individuals to infections by pathogenic Neisseria, including N. gonorrhoeae (Gc). Increasing antibiotic resistance in Gc makes new therapeutic strategies a priority. Here, we demonstrate that MAC formed by complement activity in human serum disrupts the Gc outer and inner membranes, potentiating the activity of antimicrobials against Gc and re-sensitizing multidrug resistant Gc to antibiotics. C9-depleted serum also disrupts Gc membranes and exerts antigonococcal activity, effects that are not reported in other Gram-negative bacteria. C5b-C8 complex formation potentiates Gc sensitivity to azithromycin but not lysozyme. These findings expand our mechanistic understanding of complement lytic activity, suggest a size limitation for terminal complement-mediated enhancement of antimicrobials against Gc, and suggest complement manipulation can be used to combat drug-resistant gonorrhea.

Importance

The complement cascade is a front-line arm of the innate immune system against pathogens. Complement activation results in membrane attack complex (MAC) pores forming on the outer membrane of Gram-negative bacteria, resulting in bacterial death. Individuals who cannot generate MAC are specifically susceptible to infection by pathogenic Neisseria species including N. gonorrhoeae (Gc). High rates of gonorrhea and its complications like infertility, and high-frequency resistance to multiple antibiotics, make it important to identify new approaches to combat Gc. Beyond direct anti-Gc activity, we found the MAC increases the ability of antibiotics and antimicrobial proteins to kill Gc and re-sensitizes multidrug-resistant bacteria to antibiotics. The most terminal component, C9, is needed to potentiate the anti-Gc activity of lysozyme, but azithromycin activity is potentiated regardless of C9. These findings highlight the unique effects of MAC on Gc and suggest novel translational avenues to combat drug-resistant gonorrhea.

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.

Pharmacokinetics and Bioequivalence of Two Powders of Azithromycin for Suspension: A Nonblinded, Single-Dose, Randomized, Three-Way Crossover Study in Fed and Fasting States Among Healthy Chinese Volunteers

BACKGROUND AND OBJECTIVES

Azithromycin, a macrolide antibiotic, is commonly used to treat mild-to-moderate bacterial infections. This research aimed to evaluate the pharmacokinetics (PK) properties and bioequivalence (BE) of two azithromycin (EQ 100 mg base/packet) powders for suspension in Chinese healthy participants in fed and fasting conditions.

METHODS

A total of 90 Chinese healthy participants were enrolled in this nonblinded, single-dose, randomized, semireplicate, three-period, three-sequence, crossover study. Of them, 42 and 40 were categorized to the fed and fasting conditions, respectively. The washout period between doses was 21 days. Blood specimens were harvested prior to administering the drug and 194 h following administration. The plasma levels of azithromycin were analyzed using a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) approach. PK parameters were measured using noncompartmental analysis. This research compared BE between the reference and test products using the average bioequivalence (ABE) or reference-scaled average bioequivalence (RSABE) method, considering the within-subject variability (SWR) of the reference preparation. Adverse events (AEs) were monitored to examine safety and tolerability.

RESULTS

The RSABE method (SWR ≥ 0.294) was used to determine the BE of maximal plasma concentration (Cmax) in both fed and fasting conditions. In the ABE approach, (SWR < 0.294) was adopted to assess the BE of the area under the plasma concentration-time curve from time zero to the last measurable time point (AUC0-t) and determine the area under the plasma concentration time curve from time zero to time infinity (AUC0-inf). In the fasting condition, the point estimate of the test/reference ratio for Cmax was 1.08, with a 95% upper confidence bound of - 0.05 < 0.00. The geometric mean ratio (GMRs) for AUC0-t and AUC0-inf was 115.21% [90% confidence interval (CI) 107.25-123.27%] and 113.07% (90% CI 105.14-121.61%), respectively. In the fed condition, the point estimate of the test/reference ratio for Cmax was 0.94, with a 95% upper confidence bound of - 0.10 < 0.00. The GMR for AUC0-t and AUC0-inf was 99.51% (90% CI of 91.03-108.78%) and 99.43% (90% CI 91.73-107.78%), respectively. These data all satisfied the BE criteria for drugs with high variability. All AEs were transient and mild, and no severe AEs were observed.

CONCLUSIONS

Our study indicated that the test and reference products of azithromycin (EQ 100 mg base/packet) powder for suspension were bioequivalent and safe in healthy Chinese participants, irrespective of the feeding condition. CLINICAL TRIAL REGISTRATION (CHINADRUGTRIALS.ORG.CN): CTR20232646, registered on 25 August 2023.

Therapeutic Interventions for Pseudomonas Infections in Cystic Fibrosis Patients: A Review of Phase IV Trials

Pseudomonas aeruginosa (Pa) poses a significant threat to individuals with cystic fibrosis (CF), as this bacterium is highly adaptable and resistant to antibiotics. While early-stage Pa infections can often be eradicated with aggressive antibiotic therapy, chronic infections are nearly impossible to eliminate and require treatments that focus on long-term bacterial suppression. Without such suppression, these persistent infections can severely damage the lungs, leading to serious complications and a reduced life expectancy for CF patients. Evidence for a specific treatment regimen for managing Pa infections in CF patients remains limited. This narrative review provides a detailed analysis of antimicrobial therapies assessed in completed phase IV trials, focusing on their safety and efficacy, especially with prolonged use. Key antibiotics, including tobramycin, colistin, meropenem, aztreonam, ceftolozane/tazobactam, ciprofloxacin, and azithromycin, are discussed, emphasizing their use, side effects, and delivery methods. Inhaled antibiotics are preferred for their targeted action and minimal side effects, while systemic antibiotics offer potency but carry risks like nephrotoxicity. The review also explores emerging treatments, such as phage therapy and antibiofilm agents, which show promise in managing chronic infections. Nonetheless, further research is necessary to enhance the safety and effectiveness of existing therapies while investigating new approaches for better long-term outcomes.

Oxydifficidin, a potent Neisseria gonorrhoeae antibiotic due to DedA assisted uptake and ribosomal protein RplL sensitivity

Gonorrhea, which is caused by Neisseria gonorrhoeae, is the second most reported sexually transmitted infection worldwide. The increasing appearance of isolates that are resistant to approved therapeutics raises the concern that gonorrhea may become untreatable. Here, we serendipitously identified oxydifficidin as a potent N. gonorrhoeae antibiotic through the observation of a Bacillus amyloliquefaciens contaminant in a lawn of N. gonorrhoeae. Oxydifficidin is active against both wild-type and multidrug-resistant N. gonorrhoeae. It's potent activity results from a combination of DedA-assisted uptake into the cytoplasm and the presence of an oxydifficidin-sensitive ribosomal protein L7/L12 (RplL). Our data indicates that oxydifficidin binds to the ribosome at a site that is distinct from other antibiotics and that L7/L12 is uniquely associated with its mode of action. This study opens a potential new avenue for addressing antibiotic resistant gonorrhea and underscores the possibility of identifying overlooked natural products from cultured bacteria, particularly those with activity against previously understudied pathogens.

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.

Solvent-free method for masking the bitter taste of azithromycin dihydrate using supercritical fluid technology

INTRODUCTION AND PURPOSE

The unpleasant extremely bitter taste of the orally administered broad-spectrum antibiotic azithromycin decreases patient compliance, especially in pediatrics. This issue can be overcome by decreasing drug interaction with the tasting buds using insoluble polymers at salivary pH (6.8 - 7.4), like the cationic polymer Eudragit EPO. Supercritical fluid technology is a green synthesis method for preparing pharmaceutical preparations that replace organic solvents with safe supercritical CO2. This study aimed to mask the bitter taste of azithromycin using the supercritical fluid method and a pH-sensitive Eudragit EPO polymer.

METHODS

A foaming process was investigated for preparing a formulation (TEST), which comprises treating the polymer with supercritical carbon dioxide (CO2) fluid to prepare a taste-masked dosage form without employing organic solvents or flavors.

RESULTS

The use of the supercritical technique at 40 °C and 10 MPa for 2 h allowed the manufacturing of solvent-free polymeric foam with azithromycin dispersions; the average calculated percentage of apparent volume change was 62.5 ± 5.9% with an average pore diameter of 34.879 Å. The formulated sample showed low drug release in simulated salivary fluid while keeping its crystalline nature. Moreover, clinical studies on healthy subjects showed that the formula successfully masked azithromycin's bitter taste.

CONCLUSIONS

Overall, it has been shown herein that the supercritical fluid technology foaming method is promising in masking the bitter taste of bitter ingredients.

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.

Chitosan-Coated Azithromycin/Ciprofloxacin-Loaded Polycaprolactone Nanoparticles: A Characterization and Potency Study

Purpose

Antimicrobial resistance is a major health hazard worldwide. Combining azithromycin (AZ) and ciprofloxacin (CIP) in one drug delivery system was proposed to boost their antibacterial activity and overcome resistance. This study aims to improve azithromycin and ciprofloxacin activity by co-encapsulating them inside chitosan-coated polymeric nanoparticles and evaluating their antibacterial activity.

Methods

The double emulsion method was employed to co-encapsulate AZ/CIP inside chitosan-coated polymeric nanoparticles. The formulations were evaluated for their nanoparticle size, size distribution, and zeta potential. Differential scanning calorimetry (DSC) analysis characterized the formula's thermal sustainability. Encapsulation efficiency was measured by HPLC and spectrophotometric analysis. Morphological studies used the Transmission Electron Microscopy (TEM). The in vitro release profiles of both AZ and CIP were monitored utilizing the dialysis membrane bag method. The micro-dilution assay assessed the antimicrobial activity against a clinical isolate of Klebsiella pneumoniae.

Results

The prepared AZ/CIP-poly-caprolactone nanoparticles were spherical; their size range was 184.0 ± 3.3-190.4 ± 5.6 nm and had high size uniformity (poly-dispersity index below 0.2). The zeta potential ranged from -21.2 ± 2.4 to -27.0 ± 2.5 mV, while chitosan-coated nanoparticles showed a positive zeta potential value ranging from 8 to 11 mV. The thermal study confirmed the amorphous state of both antibiotics inside the nanoparticles. The results of the in vitro release study indicated a slow and uniform rate of release for both drugs extended over 4-days, with a faster rate in the case of AZ. The MIC values reported for both chitosan-coated NP have been tremendously reduced by at least 15 folds of pure CIP and more than 60 folds of pure AZ.

Conclusion

The co-encapsulation of AZ/CIP into chitosan-coated polymeric nanoparticles has been successfully achieved. The produced particles showed many beneficial attributes of uniform particle sizes below 200 nm and high zeta potential values. Chitosan-coated polymeric nanoparticles extensively enhanced the antibacterial activity of both AZ/CIP against bacteria.

Randomized Double-Masked Placebo-Controlled Trial for the Management of Pythium Keratitis: Combination of Antibiotics Versus Monotherapy

PURPOSE

The aim of this study was to compare the efficacy of monotherapy (topical linezolid 0.2%) versus a combination of antibiotics (topical linezolid 0.2% and topical azithromycin 1%) for the treatment of Pythium insidiosum keratitis.

METHODS

Cases of P. insidiosum keratitis were prospectively randomized into group A on topical 0.2% linezolid along with topical placebo (sodium carboxymethyl cellulose [CMC] 0.5%) and group B on a combination of topical 0.2% linezolid and topical 1% azithromycin. Both groups were compared by proportion of both clinical resolution and worsening of keratitis along with the number of therapeutic penetrating keratoplasty (TPK) performed at 3 months.

RESULTS

We initially planned N = 66 patients but later limited to 20 (N = 10 in each group) patients owing to one interim analysis. The average size of the infiltrate in group A and B was 5.6 ± 1.5 mm and 4.8 ± 2.0 mm, respectively, with a mean Logarithm of the Minimum Angle of Resolution (logMAR) visual acuity of 2.74 ± 0.55 and 1.79 ± 1.19. At 3 months, from group A, 7 (70%) patients needed TPK and 2 patients had signs of resolution, whereas from group B, 6 (60%) patients achieved complete resolution ( P = 0.0003) and 2 were improving while only 1 needed TPK ( P = 0.02). The median duration of treatment in group A and B, with the study drugs, was 31 days (17.8-47.8) and 101.5 days (80-123.3), P value = 0.003, respectively. Final visual acuity at 3 months was 2.50 ± 0.81 and 0.75 ± 0.87, P = 0.02, respectively.

CONCLUSIONS

A combination of topical linezolid and topical azithromycin was found to have superior efficacy than the monotherapy with topical linezolid for the management of Pythium keratitis.

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.

Fatty acid metabolization and insulin regulation prevent liver injury from lipid accumulation in Himalayan marmots

Fat storage and weight gain are dominant traits for hibernating mammals. However, excessive fat accumulation may cause liver damage. Here, we explore the lipid accumulation and metabolic processes of the Himalayan marmot (Marmota himalayana), a hibernating rodent species. We find that the unsaturated fatty acid (UFA) content in food was consistent with a large increase in the body mass of Himalayan marmots. Metagenomic analysis shows that Firmicutes Bacterium CAG:110 plays a synergistic role by synthesizing UFAs, which is demonstrated by fecal transplantation experiments, indicating that the gut microbiome promotes fat storage in Himalayan marmots for hibernation. Microscopic examination results indicate that the risk of fatty liver appears at maximum weight; however, liver function is not affected. Upregulations of UFA catabolism and insulin-like growth factor binding protein genes provide an entry point for avoiding liver injury.

Retrospective Analysis of Azithromycin-Resistant Ureaplasma urealyticum and Mycoplasma hominis Cervical Infection Among Pregnant Women

Purpose

Ureaplasma urealyticum and Mycoplasma hominis began to show resistance to azithromycin, a macrolide antibiotic commonly used in pregnancy. Unfortunately, there are few effective and safe drugs in the clinic for genital mycoplasmas in pregnant women. In the present study, we investigated the prevalence of azithromycin-resistant U. urealyticum and M. hominis infections in pregnant women. The secondary research objects were possible influencing factors and consequences of insensitive Mycoplasma infection.

Patients and methods

A retrospective analysis was carried out in pregnant women who underwent cervical Mycoplasma culture between October 2020 and October 2021 at a large general hospital in eastern China. The sociological characteristics and clinical information of these women were collected and analyzed.

Results

A total of 375 pregnant women were enrolled, and 402 cultured mycoplasma specimens were collected. Overall, 186 (49.60%) patients tested positive cervical Mycoplasma infection, and 37 (9.87%) had infections caused by azithromycin-resistant Mycoplasma. In total, 39 mycoplasma samples were insensitive to azithromycin in vitro, also showing extremely high resistance to erythromycin, roxithromycin, and clarithromycin. Azithromycin was the only antibiotic used in women with Mycoplasma cervical infection, regardless of azithromycin resistance in vitro. Statistical results showed that azithromycin-resistant cervical Mycoplasma infection in pregnant women was unrelated to age, body mass index (BMI), gestational age, number of embryos, and assisted reproductive technology (ART) use, but led to a significantly increased incidence of adverse pregnancy outcomes (spontaneous abortion (SA), preterm birth (PTB), preterm prelabor rupture of membranes (PPROM), and stillbirth).

Conclusion

Azithromycin-resistant U. urealyticum and M. hominis cervical infections are relatively common during pregnancy, and can increase the risk of adverse pregnancy outcomes; however, there is currently a lack of safe and effective drug treatments. Herein, we show that azithromycin-resistant mycoplasma infection requires timely intervention.

Preparations and characterizations of effervescent granules containing azithromycin solid dispersion for children and elder: Solubility enhancement, taste-masking, and digestive acidic protection

Azithromycin, a macrolide antibiotics, is one of the frequently used drugs in the children and elder. However, due to these population difficulty in swallowing and inefficient absorption, and azithromycin inherent poor solubility, bitter taste, and instability in the stomach acidic condition, it is a challenge to reach high oral bioavailability of this drug. To overcome these issues, we developed and characterized the effervescent granules containing azithromycin solid dispersion. Firstly, the solid dispersion was prepared, employing both wet grinding and solvent evaporation methods, with different types/amounts of polymers. The optimal solid dispersion with β-cyclodextrin at a drug:polymer ratio of 1:2 (w/w), prepared by the solvent evaporation method, significantly enhanced the azithromycin solubility 4-fold compared to the free drug, improved its bitterness from "bitter" to "normal", possessed intermolecular bonding between the drug and polymer, and transformed the azithromycin molecules from crystalline to amorphous state. Secondly, the effervescent granules incorporating the solid dispersion were formulated with varied excipients of sweeteners, gas-generators, pH modulators, and glidants/lubricants. The optimal formula satisfied all the properties stated in the Vietnamese Pharmacopoeia. In summary, the final effervescent granules product could be further investigated in in-vivo and in clinical settings to become a potential azithromycin delivery system with high bioavailability for the children and elder.

Development of taste masking microcapsules containing azithromycin by fluid bed coating for powder for suspension and in vivo evaluation

This research aims to develop bitter taste masking microcapsules containing azithromycin by a simpler and familiar method, fluid-bed coating technology, in comparison with Zithromax®. Cores of microcapsules, azithromycin microparticles, were prepared by fluid-bed granulation, then taste-masking polymer was covered on by fluid-bed coating technique. Eudragit L100, Eudragit RL100, ethyl cellulose in single and combined with Eudragit L100, Eudragit E100 were used as taste-masking polymers. The obtained microcapsules were characterized by taste masking ability, in-vitro release, SEM, coating thickness and coating efficiency. Combination of ethyl cellulose and Eudragit E100 (3:1) in coating thickness of 45.13 ± 2.12% w/w prevent azithromycin release from microcapsules below bitter taste threshold (1.78 ± 1.17 μg/ml). Bioavailability of powders containing azithromycin microcapsules and pH modulators (50mg Na₃PO₄ and 35mg Mg(OH)₂) was not significantly different from the reference product (Zithromax®, Pfizer) in the rabbit model (p > 0.05). These results support the possibility of developing a generic product containing azithromycin.

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.

3-Amino-Substituted Analogues of Fusidic Acid as Membrane-Active Antibacterial Compounds

Fusidic acid (FA) is an antibiotic with high activity against Staphylococcus aureus; it has been used in clinical practice since the 1960s. However, the narrow antimicrobial spectrum of FA limits its application in the treatment of bacterial infections. In this regard, this work aims both at the study of the antimicrobial effect of a number of FA amines and at the identification of their potential biological targets. In this way, FA analogues containing aliphatic and aromatic amino groups and biogenic polyamine, spermine and spermidine, moieties at the C-3 atom, were synthesized (20 examples). Pyrazinecarboxamide-substituted analogues exhibit a high antibacterial activity against S. aureus (MRSA) with MIC ≤ 0.25 μg/mL. Spermine and spermidine derivatives, along with activity against S. aureus, also inhibit the growth and reproduction of Gram-negative bacteria Escherichia coli, Acinetobacter baumannii, and Pseudomonas aeruginosa, and have a high fungicidal effect against Candida albicans and Cryptococcus neoformans. The study of the membrane activity demonstrated that the spermidine- and spermine-containing compounds are able to immerse into membranes and disorder the lipidsleading to a detergent effect. Moreover, spermine-based compounds are also able to form ion-permeable pores in the lipid bilayers mimicking the bacterial membranes. Using molecular docking, inhibition of the protein synthesis elongation factor EF-G was proposed, and polyamine substituents were shown to make the greatest contribution to the stability of the complexes of fusidic acid derivatives with biological targets. This suggests that the antibacterial effect of the obtained compounds may be associated with both membrane activity and inhibition of the elongation factor EF-G.

Investigation of the photoactivation effect of TiO2 onto carbon-clay paste electrode by cyclic voltammetry analysis

In this work, a cyclic voltammetry analysis for the detection of Ascorbic Acid (AA) based on a carbon-clay paste electrode modified with titanium dioxide (CPEA/TiO₂) is presented. The electrochemical sensor was prepared using clay and carbon graphite, mixed with TiO₂ to investigate the electrode behavior towards the detection of AA. Comprehensive characterization approaches including X-ray diffraction (XRD), Selected area electron diffraction (SAED), Transmission electron microscopy (TEM), Fourier transform infra-red spectroscopy (FTIR) were carried out on different samples. The results indicated that, the electrode has been effectively modified, while the electrochemical parameters of AA on CPEA/T_iO₂/UV such as the charge transfer coefficient (α _a ), number of electrons (n) transferred and standard potential were calculated. CPEA/TiO₂/UV exhibit better photoactivity and also higher electronic conductivity under light radiation (100 W). The linear range for AA was determined between 0.150μM and 0.850 μM with the straight-line equation equivalent to I p a ( μ A ) = 2.244 [ A A ] + 1.234 (n = 8, R² = 0.993). The limit of detection was 0.732 μM (3σ) and limit of quantification was 2.440 μM. For the analytical applications, pharmaceutical tablets such as Chloroquine phosphate, Azithromycin and Hydroxychloroquine sulfate were performed. In addition, interference study in the analytical application was performed, and it was found that the electroanalytical method used can be well adopted for simultaneous electrochemical detection of AA and Azithromycin.

Pythium insidiosum keratitis: Review of literature of 5 years' clinical experience at a tertiary eye care center

BACKGROUND

Pythium insidiosum is an important cause of infectious keratitis from tropical and sub-tropical countries. Due to its closely mimicking clinical and microbiological features with fungus, it remained unidentified and managed as fungal keratitis for a long time. Previously all patients had poor outcomes with antifungal therapy and needed surgical treatment with higher rates of recurrences of infection leading to loss of an eye. Thus, a novel approach was required to treat it and, in this article, we would like to elaborate on the drastic change which these 5 years have brought in the management of this condition.

METHODS

In view of making a consolidated article comprising all the required information and also our clinical experience in the management of Pythium keratitis, we extensively reviewed several articles available on it over PubMed and Google scholars. Relevant literature describing details about Pythium, its clinical correlation, and recent advances from 52 articles including 12 articles from our group were finally included.

RESULTS

Our group identified and highlighted the unique clinical and microbiological features of Pythium insidiosum, performed several in-vitro, in-vivo studies along with clinical trials, and proposed the strategic way of its diagnosis and treatment. The use of antifungals was replaced with antibacterial medications and this resulted in better medical and surgical outcomes.

CONCLUSION

The diagnosis and management of Pythium insidiosum is constantly evolving with several recent works pointing out the possible changes in the practice patterns for the management of this challenging form of keratitis.

Relative Risk Assessment for Substandard Antibiotics Along the Manufacturing and Supply Chain: A Proof-of-Concept Study

BACKGROUND

Ensuring good quality of antibiotics is essential for desired health outcomes. Risk assessment of products for quality issues arising along the manufacturing and supply chain can thus have an important role in surveillance and management of interventions designed to reduce the burden of substandard antibiotics. Demonstrated and validated risk assessments are currently limited.

OBJECTIVES

The objective of this study was to investigate whether a comparative risk assessment framework, which adapts the WHO criteria for estimating risks for quality issues posed by individual medicines, is applicable and can identify antibiotics with a higher relative risk of substandard prevalence.

METHODS

For a proof-of-concept study, a set of antibiotics from the WHO essential medicines list was selected. Quantitative and qualitative data were extracted for each risk assessment criteria pertaining to severity and probability. A final risk matrix was then compared to field data for validation.

RESULTS

Antibiotic products were classified by relative risk. Of all the antibiotic products assessed (n = 28), 32% were categorized as highest risk, 46% as high risk, 18% as medium risk, and 4% as lowest risk. The comparison of the risk scores and incidence of quality failure from the USP Medicines Quality Database showed significant correlation.

CONCLUSION

The framework and extracted data sets appear applicable to determine relative risk for substandard antibiotics. Results of the risk matrix may be valuable for guiding pharmacovigilance, surveillance strategies, standardizing risk-based approaches, and mitigation efforts. Refinement with increased data availability may improve results.

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.

High prevalence of antimicrobial resistance and multidrug resistance among bacterial isolates from diseased pets: Retrospective laboratory data (2015-2017)

Laboratory surveillance and the monitoring of antimicrobial resistance (AMR) trends and patterns among local isolates have been highly effective in providing comprehensive information for public health decision-making. A total of 396 cases along with 449 specimens were received for antibiotic susceptibility testing at a public university veterinary diagnostic laboratory in Malaysia between 2015 and 2017. Escherichia coli was the most frequently isolated (n = 101, 13%) bacteria, followed by Staphylococcus pseudintermedius (n = 97, 12%) and Streptococcus canis (n = 62, 8%). In cats, S. pseudintermedius isolates were highly resistant to azithromycin (90%), while the E. coli isolates were highly resistant to doxycycline (90%), tetracycline (81%), and cephalexin (75%). About 55% of S. pseudintermedius and 82% of E. coli were multi-drug resistant (MDR). In dogs, S. intermedius isolates were highly resistant to aminoglycosides neomycin (90.9%) and gentamicin (84.6%), and tetracycline (75%). Whereas the E. coli isolates were highly resistant to cephalexin (82.1%) and amoxicillin/clavulanic acid (76.5%). MDR was observed in 60% of S. intermedius and 72% of E. coli from dogs. Generally, the bacterial isolates from cats demonstrated higher levels of resistance to multiple antibiotics compared to those from dogs.

Azithromycin Adsorption onto Different Soils

The antibiotic azithromycin (AZM) is one of the most persistent in the environment, with potential to cause serious health and environmental problems. As some polluting discharges containing this antibiotic can reach the soil, it is clearly relevant determining the ability of soils with different characteristics to retain it. In this research, AZM adsorption and desorption were studied for a variety of soils, using batch-type experiments. The results show that, at low doses of antibiotic added (less than or equal to 50 µmol L−1), the adsorption always reached 100%, while when higher concentrations were added (between 200 and 600 µmol L−1) the highest adsorption corresponded to soils with higher pH values. Adsorption data were fitted to the Linear, Langmuir and Freundlich models, with the latter showing the best fit, in view of the determination coefficient. No desorption was detected, indicating that AZM is strongly adsorbed to the soils evaluated, suggesting that the risks of environmental problems due to this contaminant are minimized for these edaphic media. These results can be considered relevant with respect to risk assessment and possible programming of measures aimed at controlling environmental contamination by emerging contaminants, especially from the group of antibiotics, and in particular from AZM.

Therapeutic Options for Chlamydia trachomatis Infection: Present and Future

Sexually transmitted infections (STIs), such as Chlamydia trachomatis (Ct) infection, have serious consequences for sexual and reproductive health worldwide. Ct is one of the most common sexually transmitted bacterial infections in the world, with approximately 129 million new cases per year. C. trachomatis is an obligate intracellular Gram-negative bacterium. The infection is usually asymptomatic, notwithstanding, it could also be associated with severe sequels and complications, such as chronic pain, infertility, and gynecologic cancers, and thus there is an urgent need to adequately treat these cases in a timely manner. Consequently, beyond its individual effects, the infection also impacts the economy of the countries where it is prevalent, generating a need to consider the hypothesis of implementing Chlamydia Screening Programs, a decision that, although it is expensive to execute, is a necessary investment that unequivocally will bring financial and social long-term advantages worldwide. To detect Ct infection, there are different methodologies available. Nucleic acid amplification tests, with their high sensitivity and specificity, are currently the first-line tests for the detection of Ct. When replaced by other detection methods, there are more false negative tests, leading to underreported cases and a subsequent underestimation of Ct infection's prevalence. Ct treatment is based on antibiotic prescription, which is highly associated with drug resistance. Therefore, currently, there have been efforts in line with the development of alternative strategies to effectively treat this infection, using a drug repurposing method, as well as a natural treatment approach. In addition, researchers have also made some progress in the Ct vaccine development over the years, despite the fact that it also necessitates more studies in order to finally establish a vaccination plan. In this review, we have focused on the therapeutic options for treating Ct infection, expert recommendations, and major difficulties, while also exploring the possible avenues through which to face this issue, with novel approaches beyond those proposed by the guidelines of Health Organizations.

Highly Sensitive Electrochemical Detection of Azithromycin with Graphene-Modified Electrode

An electrochemical cell containing two graphite rods was filled with the appropriate electrolyte (0.2 M ammonia + 0.2 M ammonium sulphate) and connected to the exfoliation system to synthesize graphene (EGr). A bias of 7 V was applied between the anode and cathode for 3 h. After synthesis, the morphology and structure of the sample was characterized by SEM, XRD, and FTIR techniques. The material was deposited onto the surface of a glassy carbon (GC) electrode (EGr/GC) and employed for the electrochemical detection of azithromycin (AZT). The DPV signals recorded in pH 5 acetate containing 6 × 10^-5 M AZT revealed significant differences between the GC and EGr/GC electrodes. For EGr/GC, the oxidation peak was higher and appeared at lower potential (+1.12 V) compared with that of bare GC (+1.35 V). The linear range for AZT obtained with the EGr/GC electrode was very wide, 10^-8-10^-5 M, the sensitivity was 0.68 A/M, and the detection limit was 3.03 × 10^-9 M. It is important to mention that the sensitivity of EGr/GC was three times higher than that of bare GC (0.23 A/M), proving the advantages of using graphene-modified electrodes in the electrochemical detection of AZT.

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.

Influence of yeast-based pre- and probiotics in lactation and nursery diets on nursery pig performance and antimicrobial resistance of fecal Escherichia coli

Two experiments were conducted to determine the impact of various combinations of yeast-based direct fed microbials (DFM) in diets fed to nursery pigs weaned from sows fed lactation diets with or without yeast additives. In Exp. 1, 340 weaned pigs, initially 5.1 kg ± 0.02, were used to evaluate previous sow treatment (control vs yeast additives) and nursery diets with or without added yeast-based DFM on growth performance and antimicrobial resistance (AMR) patterns of fecal Escherichia coli. Treatments were arranged in a 2 × 2 factorial with main effects of sow treatment (control vs. yeast-based pre- and probiotic diet; 0.10% ActiSaf Sc 47 HR+ and 0.025% SafMannan, Phileo by Lesaffre, Milwaukee, WI) and nursery treatment (control vs. yeast-based pre- and probiotic diet; 0.10% ActiSaf Sc 47 HR+, 0.05% SafMannan, and 0.05% NucleoSaf from d 0 to 7, then concentrations were decreased by 50% from d 7 to 24) with 5 pigs per pen and 17 replications per treatment. Progeny from sows fed yeast additives had increased (P < 0.05) average daily gain (ADG) from d 0 to 24 and d 0 to 45. However, pigs that were fed yeast additives for the first 24 d in the nursery tended to have decreased d 0 to 45 ADG (P = 0.079). Fecal E. coli isolated from pigs from the sows fed yeast group had increased (P = 0.034) resistance to nalidixic acid and a tendency for increased resistance to ciprofloxacin (P = 0.065) and gentamicin (P = 0.054). Yet, when yeast additives were added in the nursery there was reduced (P < 0.05) fecal E. coli resistance to azithromycin and chloramphenicol. In Exp. 2, 330 weaned pigs, initially 5.8 kg ± 0.03, were used to evaluate diets with two different combinations of DFM on growth performance. Treatments were arranged in a 2 × 3 factorial with main effects of sow treatment (same as described in Exp. 1) and nursery treatment (control; YCW, 0.05% of SafMannan from d 0 to 38 and NucleoSaf at 0.05% from d 0 to 10 and 0.025% from d 10 to 24; or DFM, 0.10% MicroSaf-S from d 0 to 38 and NucleoSaf at 0.05% from d 0 to 10 and 0.025% from d 10 to 24) with 6 pigs per pen and 8 to 10 replications per treatment. From d 0 to 10 post-weaning, progeny of sows fed yeast additives had increased (P < 0.05) ADG and G:F. In conclusion, feeding sows yeast through lactation improved offspring growth performance in the nursery. While feeding live yeast and yeast extracts reduced nursery pig performance in Exp. 1, feeding DFM improved growth later in the nursery period in Exp. 2.

Mechanism of action, resistance, synergism, and clinical implications of azithromycin

Background

Azithromycin (AZM), sold under the name Zithromax, is classified as a macrolide. It has many benefits due to its immunomodulatory, anti‐inflammatory, and antibacterial effects. This review aims to study different clinical and biochemisterial aspects and properties of this drug which has a priority based on literature published worldwide.

Methods

Several databases including Web of Science, Google Scholar, PubMed, and Scopus were searched to obtain the relevant studies.

Results

AZM mechanism of action including the inhibition of bacterial protein synthesis, inhibition of proinflammatory cytokine production, inhibition of neutrophil infestation, and macrophage polarization alteration, gives it the ability to act against a wide range of microorganisms. Resistant organisms are spreading and being developed because of the irrational use of the drug in the case of dose and duration. AZM shows synergistic effects with other drugs against a variety of organisms. This macrolide is considered a valuable antimicrobial agent because of its use as a treatment for a vast range of diseases such as asthma, bronchiolitis, COPD, cystic fibrosis, enteric infections, STIs, and periodontal infections.

Conclusions

Our study shows an increasing global prevalence of AZM resistance. Thus, synergistic combinations are recommended to treat different pathogens. Moreover, continuous monitoring of AZM resistance by registry centers and the development of more rapid diagnostic assays are urgently needed.

Development of 3D Printed Biodegradable Mesh with Antimicrobial Properties for Pelvic Organ Prolapse

To address the increasing demand for safe and effective treatment options for pelvic organ prolapse (POP) due to the worldwide ban of the traditional polypropylene meshes, this study introduced degradable polycaprolactone (PCL)/polyethylene glycol (PEG) composite meshes fabricated with melt-electrowriting (MEW). Two PCL/PEG mesh groups: 90:10 and 75:25 (PCL:PEG, wt%) were fabricated and characterized for their degradation rate and mechanical properties, with PCL meshes used as a control. The PCL/PEG composites showed controllable degradation rates by adjusting the PEG content and produced mechanical properties, such as maximal forces, that were higher than PCL alone. The antibacterial properties of the meshes were elicited by coating them with a commonly used antibiotic: azithromycin. Two dosage levels were used for the coating: 0.5 mg and 1 mg per mesh, and both dosage levels were found to be effective in suppressing the growth of S. aureus bacteria. The biocompatibility of the meshes was assessed using human immortalized adipose derived mesenchymal stem cells (hMSC). In vitro assays were used to assess the cell viability (LIVE/DEAD assay), cell metabolic activity (alamarBlue assay) and cell morphology on the meshes (fluorescent and electron microscopy). The cell attachment was found to decrease with increased PEG content. The freshly drug-coated meshes showed signs of cytotoxicity during the cell study process. However, when pre-released for 14 days in phosphate buffered saline, the initial delay in cell attachment on the drug-coated mesh groups showed full recovery at the 14-day cell culture time point. These results indicated that the PCL/PEG meshes with antibiotics coating will be an effective anti-infectious device when first implanted into the patients, and, after about 2 weeks of drug release, the mesh will be supporting cell attachment and proliferation. These meshes demonstrated a potential effective treatment option for POP that may circumvent the issues related to the traditional polypropylene meshes.

Antimalarial Natural Products

Natural products have made a crucial and unique contribution to human health, and this is especially true in the case of malaria, where the natural products quinine and artemisinin and their derivatives and analogues, have saved millions of lives. The need for new drugs to treat malaria is still urgent, since the most dangerous malaria parasite, Plasmodium falciparum, has become resistant to quinine and most of its derivatives and is becoming resistant to artemisinin and its derivatives. This volume begins with a short history of malaria and follows this with a summary of its biology. It then traces the fascinating history of the discovery of quinine for malaria treatment and then describes quinine's biosynthesis, its mechanism of action, and its clinical use, concluding with a discussion of synthetic antimalarial agents based on quinine's structure. The volume then covers the discovery of artemisinin and its development as the source of the most effective current antimalarial drug, including summaries of its synthesis and biosynthesis, its mechanism of action, and its clinical use and resistance. A short discussion of other clinically used antimalarial natural products leads to a detailed treatment of other natural products with significant antiplasmodial activity, classified by compound type. Although the search for new antimalarial natural products from Nature's combinatorial library is challenging, it is very likely to yield new antimalarial drugs. The chapter thus ends by identifying over ten natural products with development potential as clinical antimalarial agents.

Therapeutic options in coronavirus treatment

This chapter details the various therapeutic options available for the treatment of the novel coronavirus, SARS-CoV-2, that has brought the world to a standstill. As at 3.53 CEST, June 28, 2020, WHO reported 9,843,073 confirmed cases of COVID-19, with a death toll of 495,760. The rate of the spread of this disease is alarming posing serious threat to the world healthcare system. Clinical investigations and research are on the way for the development of vaccines or antiviral drugs. Despite this effort, no medication has been found to be very effective for its treatment. In this chapter, emphasis was laid on the need for repurposing of antiviral drugs to combat COVID-19 along with other alternatives such as convalescent plasma therapy and exploitation of drugs from medicinal plants and other natural resources.

A critical analysis about the supposed role of azithromycin in the treatment of covid-19

After over one year, the coronavirus disease 2019 (covid-19) has still affected millions of people. For this reason, global efforts to promote better treatment of covid-19 have been undertaken focused on the repurposing of existing medications.In Brazil, azithromycin, a broad-spectrum antibiotic, has been used in association with other drugs as an immunomodulatory, anti-inflammatory, and anti-viral agent, regardless of bacterial co-infection. Indeed, data from experimental studies have demonstrated the capacity of this drug in reducing the production of infection-induced pro-inflammatory cytokines, such as IL-8, IL-6, and TNF-alpha. However, observational studies revealed conflicting results regarding its effect, whereas well-conducted clinical trials have not shown a considerable effect of this agent on the improvement of clinical outcomes. This narrative review addressed the possible role of this antibiotic in the management of covid-19, based on data from clinical and preclinical studies.

Recent Updates in Experimental Research and Clinical Evaluation on Drugs for COVID-19 Treatment

Since the outbreak of corona virus disease 2019 (COVID-19) in Wuhan (China) in December 2019, the epidemic has rapidly spread to many countries around the world, posing a huge threat to global public health. In response to the pandemic, a number of clinical studies have been initiated to evaluate the effect of various treatments against COVID-19, combining medical strategies and clinical trial data from around the globe. Herein, we summarize the clinical evaluation about the drugs mentioned in this review for COVID-19 treatment. This review discusses the recent data regarding the efficacy of various treatments in COVID-19 patients, to control and prevent the outbreak.

Photo-mediated and advanced oxidative processes applied for the treatment of effluents with drugs used for the treatment of early COVID-19: Review

The COVID-19 pandemic is proving to be one of the most challenging health and social crises ever faced by humanity. Several drugs have been proposed as potential antiviral agents for the treatment of COVID-19 since the beginning of the health crisis. Among them are chloroquine (CQ), hydroxychloroquine (HCQ), ivermectin (IVM), and the combination of QC or HCQ and azithromycin (AZI). The use of these and several other drugs has grown sharply, even if there is proof of ineffectiveness in the early treatment or mild cases of COVID-19. Thus, there is great concern about the potential environmental impacts of the effluents released with the presence of these drugs. Therefore, this work aimed to carry out a literature review on wastewater treatment processes, focusing on removing these substances through advanced oxidation process. As the conventional effluent treatment processes do not have high efficiency for removal, it was concentrated in the literature that had as scope advanced and photo-mediated techniques to remove CQ, HCQ, IVM, and AZI. It is expected, with this work, to highlight the importance of conducting research that contributes to the control of pollution and contamination.

Effect of Azithromycin on Mineralized Nodule Formation in MC3T3-E1 Cells

Azithromycin displays immunomodulatory and anti-inflammatory effects in addition to broad-spectrum antimicrobial activity and is used to treat inflammatory diseases, including respiratory and odontogenic infections. Few studies have reported the effect of azithromycin therapy on bone remodeling processes. The aim of this study was to examine the effects of azithromycin on the osteogenic function of osteoblasts using osteoblast-like MC3T3-E1 cells. Cells were cultured in the presence of 0, 0.1, 1, and 10 µg/mL azithromycin, and cell proliferation and alkaline phosphatase (ALPase) activity were determined. In vitro mineralized nodule formation was detected with alizarin red staining. The expression of collagenous and non-collagenous bone matrix protein was determined using real-time PCR or enzyme-linked immunosorbent assays. In cells cultured with 10 µg/mL azithromycin, the ALPase activity and mineralized nodule formation decreased, while the type I collagen, bone sialoprotein, osteocalcin, and osteopontin mRNA expression as well as osteopontin and phosphorylated osteopontin levels increased. These results suggest that a high azithromycin concentration (10 µg/mL) suppresses mineralized nodule formation by decreasing ALPase activity and increasing osteopontin production, whereas low concentrations (≤l.0 µg/mL) have no effect on osteogenic function in osteoblastic MC3T3-E1 cells.

Current status and strategic possibilities on potential use of combinational drug therapy against COVID-19 caused by SARS-CoV-2

The spread of new coronavirus infection starting December 2019 as novel SARS-CoV-2, identified as the causing agent of COVID-19, has affected all over the world and been declared as pandemic. Approximately, more than 8,807,398 confirmed cases of COVID-19 infection and 464,483 deaths have been reported globally till the end of 21 June 2020. Until now, there is no specific drug therapy or vaccine available for the treatment of COVID-19. However, some potential antimalarial drugs like hydroxychloroquine and azithromycin, antifilarial drug ivermectin and antiviral drugs have been tested by many research groups worldwide for their possible effect against the COVID-19. Hydroxychloroquine and ivermectin have been identified to act by creating the acidic condition in cells and inhibiting the importin (IMPα/β1) mediated viral import. There is a possibility that some other antimalarial drugs/antibiotics in combination with immunomodulators may help in combatting this pandemic disease. Therefore, this review focuses on the current use of various drugs as single agents (hydroxychloroquine, ivermectin, azithromycin, favipiravir, remdesivir, umifenovir, teicoplanin, nitazoxanide, doxycycline, and dexamethasone) or in combinations with immunomodulators additionally. Furthermore, possible mode of action, efficacy and current stage of clinical trials of various drug combinations against COVID-19 disease has also been discussed in detail.Communicated by Ramaswamy H. Sarma.

Potential drug development and therapeutic approaches for clinical intervention in COVID-19

While the vaccination is now available to many countries and will slowly dissipate to others, effective therapeutics for COVID-19 is still illusive. The SARS-CoV-2 pandemic has posed an unprecedented challenge to researchers, scientists, and clinicians and affected the wellbeing of millions of people worldwide. Since the beginning of the pandemic, a multitude of existing anti-viral, antibiotic, antimalarial, and anticancer drugs have been tested, and some have shown potency in the treatment and management of COVID-19, albeit others failed to leave any positive impact and a few also became controversial as they showed mixed clinical outcomes. In the present article, we have brought together some of the candidate therapeutic drugs being repurposed or used in the clinical trials and discussed their clinical efficacy and safety for COVID-19.

In silico investigation of pro-arrhythmic effects of azithromycin on the human ventricle

The macrolide antibiotic azithromycin (AZM) is widely used for respiratory infections and has been suggested to be a possible treatment for the Coronavirus Disease of 2019 (COVID-19). However, AZM-associated QT interval prolongation and arrhythmias have been reported. Integrated mechanistic information on AZM actions on human ventricular excitation and conduction is lacking. Therefore, this study was undertaken to investigate the actions of AZM on ventricular cell and tissue electrical activity. The O'Hara- Virag-Varro-Rudy dynamic (ORd) model of human ventricular cells was modified to incorporate experimental data on the concentration-dependent actions of AZM on multiple ion channels, including INa, ICaL, IKr, IKs, IK1 and INaL in both acute and chronic exposure conditions. In the single cell model, AZM prolonged the action potential duration (APD) in a concentration-dependent manner, which was predominantly attributable to IKr reduction in the acute condition and potentiated INaL in the chronic condition. High concentrations of AZM also increased action potential (AP) triangulation (determined as an increased difference between APD30 and APD90) which is a marker of arrhythmia risk. In the chronic condition, the potentiated INaL caused a modest intracellular Na + concentration accumulation at fast pacing rates. At the 1D tissue level, the AZM-prolonged APD at the cellular level was reflected by an increased QT interval in the simulated pseudo-ECG, consistent with clinical observations. Additionally, AZM reduced the conduction velocity (CV) of APs in the acute condition due to a reduced INa, and it augmented the transmural APD dispersion of the ventricular tissue, which is also pro-arrhythmic. Such actions were markedly augmented when the effects of chronic exposure of AZM were also considered, or with additional IKr block, as may occur with concurrent use of other medications. This study provides insights into the ionic mechanisms by which high concentrations of AZM may modulate ventricular electrophysiology and susceptibility to arrhythmia.

Utility of MALDI-TOF MS for differentiation of Neisseria gonorrhoeae isolates with dissimilar azithromycin susceptibility profiles

BACKGROUND

Antibiotic-resistant gonorrhoea has been a chronic public health burden since the mid-1930s. Recent emergence of isolates resistant to the current recommended antibiotics for gonorrhoea further magnifies the threat of untreatable gonorrhoea. The lack of new, effective antibiotics highlights the need for better understanding of the population structure of Neisseria gonorrhoeae in order to provide greater insight on how to curtail the spread of antimicrobial-resistant N. gonorrhoeae.

OBJECTIVES

To explore a potential application of MALDI-TOF MS to differentiate N. gonorrhoeae displaying different levels of susceptibility to the antibiotic azithromycin.

METHODS

We conducted MALDI-TOF MS using the Bruker Biotyper on 392 N. gonorrhoeae isolates collected through the Gonococcal Isolate Surveillance Project (GISP) and/or the Strengthening the United States Response to Resistant Gonorrhea (SURRG) project. The MALDI-TOF MS spectra were visually analysed to assess the presence of distinctive peak(s). Statistical analysis was performed to assess the relationship between gonococcal isolates with the distinct protein peak and antibiotic susceptibility.

RESULTS

In this study, we were able to differentiate N. gonorrhoeae isolates into two distinct subpopulations using MALDI-TOF MS. Isolates were distinguished by the presence or absence of a spectral peak at 11 300 Da. Notably, these two groups exhibited different levels of susceptibility to azithromycin.

CONCLUSIONS

We have shown that in addition to its ability to identify N. gonorrhoeae, MALDI-TOF MS could also be used to differentiate gonococcal isolates with different levels of susceptibility to azithromycin.

Use of glucocorticoids and azithromycin in the therapy of COVID-19

In December 2019, a new variant coronavirus, SARS-CoV-2, emerged in China, which was initially described as a pneumonia of an unknown agent. The new coronavirus spreads mainly by person-to-person transmission through close contact. The pathophysiology of COVID-19 is related to a complex immune system response that varies between people and, in severe cases of the disease, is characterized by excessive responses called "cytokine storms," which are associated with complications that can lead to a state of hypercoagulation and death. Glucocorticoids and azithromycin are drugs that may be effective in the treatment. This review aims to highlight the clinical findings that demonstrate the effectiveness of glucocorticoid and azithromycin therapy in the treatment of COVID-19. To date, many drugs have been studied for use in combination therapy, and the rapid expansion of knowledge about the virology of SARS-CoV-2 generates a more accurate direction in therapy.

Azithromycin resistance in Treponema pallidum in Reunion Island: A cross-sectional study

OBJECTIVE

Since the beginning of the 21st century, Reunion Island has experienced a syphilis epidemic. Infected patients are mostly heterosexual, with a high proportion of women, suggesting that congenital syphilis is present on the island. To determine whether azithromycin can be used for mass treatment of syphilis on Reunion Island, we assessed the prevalence of macrolide resistance in Treponema pallidum (TP).

METHODS

This monocentric cross-sectional study was conducted at the Reunion Island University Hospital. Samples were collected from lesions suggestive of primary or secondary syphilis. Samples positive for TP by multiplex polymerase chain reaction (PCR) were sent to the French National Reference Centre (NRC) for further analysis. Nested PCR-tpp47 was performed on these samples for detection of TP-DNA; 23s rRNA was amplified by PCR in confirmed positive samples. The Restriction Fragment Length Polymorphism (RFLP) technique was performed on samples with amplified 23s rRNA for detection of the A2058G mutation.

RESULTS

A total of 129 samples were collected from 119 patients. Of these, 18 tested positive for TP using multiplex PCR and were sent to the NRC. Fifteen (83.3%) of the 18 samples were confirmed positive by nested PCR-tpp47, and 23s rRNA was amplified in only 7 (38.9%) samples. Azithromycin resistance was detected in all TP strains with amplified 23s rRNA.

CONCLUSION

Amplification of 23s rRNA was successful in only 7 TP strains, all of which displayed resistance to macrolides. Keeping in mind the small sample size of our study, this suggests that azithromycin should not be used for mass treatment of syphilis in Reunion Island.