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MSphere Oct 2022Escherichia coli is intrinsically resistant to macrolides due to outer membrane impermeability, but may also acquire macrolide resistance genes by horizontal transfer....
Escherichia coli is intrinsically resistant to macrolides due to outer membrane impermeability, but may also acquire macrolide resistance genes by horizontal transfer. We evaluated the prevalence and types of acquired macrolide resistance determinants in pig clinical E. coli, and we assessed the ability of peptidomimetics to potentiate different macrolide subclasses against strains resistant to neomycin, a first-line antibiotic in the treatment of pig-enteric infections. The erythromycin MIC distribution was determined in 324 pig clinical E. coli isolates, and 62 neomycin-resistant isolates were further characterized by genome sequencing and MIC testing of azithromycin, spiramycin, tilmicosin, and tylosin. The impact on potency achieved by combining these macrolides with three selected peptidomimetic compounds was determined by checkerboard assays in six strains representing different genetic lineages and macrolide resistance gene profiles. Erythromycin MICs ranged from 16 to >1,024 μg/mL. Azithromycin showed the highest potency in wild-type strains (1 to 8 μg/mL), followed by erythromycin (16 to 128 μg/mL), tilmicosin (32 to 256 μg/mL), and spiramycin (128 to 256 μg/mL). Isolates with elevated MIC mainly carried (B), either alone or in combination with other acquired macrolide resistance genes, including (42), (C), (A), (B), and (G). All peptidomimetic-macrolide combinations exhibited synergy (fractional inhibitory concentration index [FICI] < 0.5) with a 4- to 32-fold decrease in the MICs of macrolides. Interestingly, the MICs of tilmicosin in wild-type strains were reduced to concentrations (4 to 16 μg/mL) that can be achieved in the pig intestinal tract after oral administration, indicating that peptidomimetics can potentially be employed for repurposing tilmicosin in the management of E. coli enteritis in pigs. Acquired macrolide resistance is poorly studied in Escherichia coli because of intrinsic resistance and limited antimicrobial activity in Gram-negative bacteria. This study reveals new information on the prevalence and distribution of macrolide resistance determinants in a comprehensive collection of porcine clinical E. coli from Denmark. Our results contribute to understanding the correlation between genotypic and phenotypic macrolide resistance in E. coli. From a clinical standpoint, our study provides an initial proof of concept that peptidomimetics can resensitize E. coli to macrolide concentrations that may be achieved in the pig intestinal tract after oral administration. The latter result has implications for animal health and potential applications in veterinary antimicrobial drug development in view of the high rates of antimicrobial-resistant E. coli isolated from enteric infections in pigs and the lack of viable alternatives for treating these infections.
Topics: Swine; Animals; Escherichia coli; Anti-Bacterial Agents; Azithromycin; Peptidomimetics; Macrolides; Tylosin; Drug Resistance, Bacterial; Spiramycin; Erythromycin; Escherichia coli Infections; Neomycin
PubMed: 36154672
DOI: 10.1128/msphere.00402-22 -
The Cochrane Database of Systematic... Nov 2012Macrolide antibiotics may have a modifying role in diseases which involve airway infection and inflammation, like cystic fibrosis. (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Macrolide antibiotics may have a modifying role in diseases which involve airway infection and inflammation, like cystic fibrosis.
OBJECTIVES
To test the hypotheses that, in people with cystic fibrosis, macrolide antibiotics: 1. improve clinical status compared to placebo or another antibiotic; 2. do not have unacceptable adverse effects. If benefit was demonstrated, we aimed to assess the optimal type, dose and duration of macrolide therapy.
SEARCH METHODS
We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register comprising references identified from comprehensive electronic database searches, handsearching relevant journals and abstract books of conference proceedings.We contacted investigators known to work in the field, previous authors and pharmaceutical companies manufacturing macrolide antibiotics for unpublished or follow-up data (May 2010).Latest search of the Group's Cystic Fibrosis Trials Register: 29 February 2012.
SELECTION CRITERIA
Randomised controlled trials of macrolide antibiotics compared to: placebo; another class of antibiotic; another macrolide antibiotic; or the same macrolide antibiotic at a different dose.
DATA COLLECTION AND ANALYSIS
Two authors independently extracted data and assessed risk of bias. Seven groups were contacted and provided additional data which were incorporated into the review.
MAIN RESULTS
Ten of 31 studies identified were included (959 patients). Five studies with a low risk of bias examined azithromycin versus placebo and demonstrated consistent improvement in forced expiratory volume in one second over six months (mean difference at six months 3.97% (95% confidence interval 1.74% to 6.19%; n = 549, from four studies)). Patients treated with azithromycin were approximately twice as likely to be free of pulmonary exacerbation at six months, odds ratio 1.96 (95% confidence interval 1.15 to 3.33). With respect to secondary outcomes, there was a significant reduction in need for oral antibiotics and greater weight gain in those taking azithromycin. Adverse events were uncommon and not obviously associated with azithromycin, although a once-weekly high dose regimen was associated with more frequent gastrointestinal adverse events. Treatment with azithromycin was associated with reduced identification of Staphylococcus aureus on respiratory culture, but also a significant increase in macrolide resistance.
AUTHORS' CONCLUSIONS
This review provides evidence of improved respiratory function after six months of azithromycin. Data beyond six months were less clear, although reduction in pulmonary exacerbation was sustained. Treatment appeared safe over a six-month period; however, emergence of macrolide resistance was a concern. A multi-centre trial examining long-term effects of this antibiotic treatment is needed, especially for infants recognised through newborn screening.
Topics: Anti-Bacterial Agents; Azithromycin; Bacterial Infections; Cystic Fibrosis; Disease Progression; Humans; Macrolides; Outcome Assessment, Health Care; Pseudomonas Infections; Pseudomonas aeruginosa; Randomized Controlled Trials as Topic
PubMed: 23152214
DOI: 10.1002/14651858.CD002203.pub4 -
Sheng Wu Gong Cheng Xue Bao = Chinese... Aug 2023Tacrolimus (FK506) is a 23-membered macrolide with immunosuppressant activity that is widely used clinically for treating the rejection after organ transplantation. The... (Review)
Review
Tacrolimus (FK506) is a 23-membered macrolide with immunosuppressant activity that is widely used clinically for treating the rejection after organ transplantation. The research on tacrolimus production was mainly focused on biosynthesis methods, within which there are still some bottlenecks. This review summarizes the progress made in tacrolimus biosynthesis modification of metabolic pathways and control of fermentation process, with the hope to address the technical bottlenecks for tacrolimus biosynthesis and improve tacrolimus production by fermentation engineering and metabolic engineering.
Topics: Tacrolimus; Immunosuppressive Agents; Fermentation; Macrolides; Anti-Bacterial Agents
PubMed: 37622350
DOI: 10.13345/j.cjb.220994 -
Frontiers in Cellular and Infection... 2023With the widespread use of macrolide antibiotics in China, common pathogens causing children's infections, such as , (including , ), , , and , have shown varying... (Review)
Review
With the widespread use of macrolide antibiotics in China, common pathogens causing children's infections, such as , (including , ), , , and , have shown varying degrees of drug resistance. In order to provide such problem and related evidence for rational use of antibiotics in clinic, we reviewed the drug resistance of common bacteria to macrolides in children recent 20 years.
Topics: Drug Resistance, Bacterial; Macrolides; Anti-Bacterial Agents; Bacteria; Bacterial Infections; Humans; Child; China
PubMed: 37637457
DOI: 10.3389/fcimb.2023.1181633 -
Biochemistry. Biokhimiia Dec 2010This review describes the results of recent studies of the ribosomal tunnel (RT), the major function of which is to allow the smooth passage of nascent polypeptides with... (Review)
Review
This review describes the results of recent studies of the ribosomal tunnel (RT), the major function of which is to allow the smooth passage of nascent polypeptides with different sequences from the peptidyl transferase center of the ribosome to the tunnel exit, where the folding of protein molecules begins. The features of structural organization of RT and their role in modulation and stabilization of the nascent chain conformation are discussed. Structural features of macrolide binding sites as well as application of macrolide antibiotics and their derivatives as tools to investigate ligand-tunnel wall interactions are also considered. Several examples of strong and specific interactions of regulatory polypeptides with nucleotide and amino acid residues of RT that lead to ribosome stalling and translational arrest are described in detail. The role of these events in regulation of expression of certain genes is discussed on the basis of recent high-resolution structural studies of nascent chains in the RT.
Topics: Animals; Anti-Bacterial Agents; Humans; Macrolides; Peptides; Peptidyl Transferases; Protein Biosynthesis; Protein Conformation; Ribosomes
PubMed: 21417991
DOI: 10.1134/s0006297910130018 -
Marine Drugs Apr 2019Currently, the increasing resistance of microorganisms to antibiotics is a serious problem. Marine organisms are the source of thousands of substances, which also have... (Review)
Review
Currently, the increasing resistance of microorganisms to antibiotics is a serious problem. Marine organisms are the source of thousands of substances, which also have antibacterial and antifungal effects. Among them, marine macrolides are significant. In this review, the antibacterial and/or antifungal activities of 34 groups of marine macrolides are presented. Exemplary groups are chalcomycins, curvulides, halichondramides, lobophorins, macrolactins, modiolides, scytophycins, spongistatins, or zearalanones. In the paper, 74 antibiotics or their analog sets, among which 29 with antifungal activity, 25 that are antibacterial, and 20 that are both antifungal and antibacterial are summarized. Also, 36 macrolides or their sets are produced by bacteria, 18 by fungi, ten by sponges, seven by algae, two by porifera, and one by nudibranch. Moreover, the chemical structures of representatives from each of the 34 groups of these antibiotics are presented. To summarize, marine organisms are rich in natural macrolides. Some of these may be used in the future in the treatment of bacterial and fungal infections. Marine macrolides can also be potential drugs applicable against pathogens resistant to currently known antibiotics.
Topics: Animals; Anti-Bacterial Agents; Antifungal Agents; Aquatic Organisms; Bacteria; Fungi; Humans; Macrolides
PubMed: 31018512
DOI: 10.3390/md17040241 -
Cell Mar 2023The emergence of drug-resistant tuberculosis has created an urgent need for new anti-tubercular agents. Here, we report the discovery of a series of macrolides called...
The emergence of drug-resistant tuberculosis has created an urgent need for new anti-tubercular agents. Here, we report the discovery of a series of macrolides called sequanamycins with outstanding in vitro and in vivo activity against Mycobacterium tuberculosis (Mtb). Sequanamycins are bacterial ribosome inhibitors that interact with the ribosome in a similar manner to classic macrolides like erythromycin and clarithromycin, but with binding characteristics that allow them to overcome the inherent macrolide resistance of Mtb. Structures of the ribosome with bound inhibitors were used to optimize sequanamycin to produce the advanced lead compound SEQ-9. SEQ-9 was efficacious in mouse models of acute and chronic TB as a single agent, and it demonstrated bactericidal activity in a murine TB infection model in combination with other TB drugs. These results support further investigation of this series as TB clinical candidates, with the potential for use in new regimens against drug-susceptible and drug-resistant TB.
Topics: Animals; Mice; Antitubercular Agents; Macrolides; Drug Resistance, Bacterial; Mycobacterium tuberculosis; Clarithromycin
PubMed: 36827973
DOI: 10.1016/j.cell.2023.01.043 -
Revista Espanola de Quimioterapia :... Jun 2023Mycoplasma pneumoniae is a bacterium that lacks a cell wall. It produces infections all It produces infections world-wide, in epidemic outbreaks every 4-7 years, or... (Review)
Review
Mycoplasma pneumoniae is a bacterium that lacks a cell wall. It produces infections all It produces infections world-wide, in epidemic outbreaks every 4-7 years, or endemically. Its clinical manifestations occur mostly in the respiratory tract and it is a common cause of atypical pneumonia. The treatment is with macrolides, tetracyclines or fluoroquinolones. Since 2000, an increase in resistance to macrolides has been detected worldwide, being more frequent in Asia. In Europe the frequency of resistance ranges between 1% and 25%, depending on the country. Molecular techniques and serology techniques provides very high sensitivity in diagnostic confirmation, being very useful for detecting and controlling M. pneumoniae outbreaks. The detection of resistance to macrolides requires a sequencing technique.
Topics: Humans; Mycoplasma pneumoniae; Macrolides; Drug Resistance, Bacterial; Pneumonia, Mycoplasma; Anti-Bacterial Agents; Europe
PubMed: 36966384
DOI: 10.37201/req/118.2022 -
Nature Communications Jul 2021Macrolides and ketolides comprise a family of clinically important antibiotics that inhibit protein synthesis by binding within the exit tunnel of the bacterial...
Macrolides and ketolides comprise a family of clinically important antibiotics that inhibit protein synthesis by binding within the exit tunnel of the bacterial ribosome. While these antibiotics are known to interrupt translation at specific sequence motifs, with ketolides predominantly stalling at Arg/Lys-X-Arg/Lys motifs and macrolides displaying a broader specificity, a structural basis for their context-specific action has been lacking. Here, we present structures of ribosomes arrested during the synthesis of an Arg-Leu-Arg sequence by the macrolide erythromycin (ERY) and the ketolide telithromycin (TEL). Together with deep mutagenesis and molecular dynamics simulations, the structures reveal how ERY and TEL interplay with the Arg-Leu-Arg motif to induce translational arrest and illuminate the basis for the less stringent sequence-specific action of ERY over TEL. Because programmed stalling at the Arg/Lys-X-Arg/Lys motifs is used to activate expression of antibiotic resistance genes, our study also provides important insights for future development of improved macrolide antibiotics.
Topics: Amino Acid Motifs; Amino Acid Sequence; Anti-Bacterial Agents; Bacillus subtilis; Binding Sites; Cryoelectron Microscopy; Drug Resistance, Microbial; Erythromycin; Genes, Bacterial; Ketolides; Macrolides; Methyltransferases; Molecular Dynamics Simulation; Mutagenesis, Insertional; Protein Biosynthesis; Protein Synthesis Inhibitors; Ribosomes
PubMed: 34294725
DOI: 10.1038/s41467-021-24674-9 -
American Journal of Respiratory and... Oct 2019
Topics: Anti-Bacterial Agents; Azithromycin; Double-Blind Method; Hospitalization; Humans; Macrolides; Patient Readmission; Pulmonary Disease, Chronic Obstructive
PubMed: 31188635
DOI: 10.1164/rccm.201905-0957ED