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Molecular Cell Jul 2023The spliceosome is a staggeringly complex machine, comprising, in humans, 5 snRNAs and >150 proteins. We scaled haploid CRISPR-Cas9 base editing to target the entire...
The spliceosome is a staggeringly complex machine, comprising, in humans, 5 snRNAs and >150 proteins. We scaled haploid CRISPR-Cas9 base editing to target the entire human spliceosome and investigated the mutants using the U2 snRNP/SF3b inhibitor, pladienolide B. Hypersensitive substitutions define functional sites in the U1/U2-containing A complex but also in components that act as late as the second chemical step after SF3b is dissociated. Viable resistance substitutions map not only to the pladienolide B-binding site but also to the G-patch domain of SUGP1, which lacks orthologs in yeast. We used these mutants and biochemical approaches to identify the spliceosomal disassemblase DHX15/hPrp43 as the ATPase ligand for SUGP1. These and other data support a model in which SUGP1 promotes splicing fidelity by triggering early spliceosome disassembly in response to kinetic blocks. Our approach provides a template for the analysis of essential cellular machines in humans.
Topics: Humans; Spliceosomes; Epoxy Compounds; Macrolides; RNA Splicing; Saccharomyces cerevisiae; Mutagenesis
PubMed: 37402368
DOI: 10.1016/j.molcel.2023.06.003 -
Respiratory Investigation Mar 2024The evidence for macrolide therapy in adult asthma is not properly established and remains controversial. We conducted a systematic review and meta-analysis to examine... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
The evidence for macrolide therapy in adult asthma is not properly established and remains controversial. We conducted a systematic review and meta-analysis to examine the efficacy and safety of macrolide therapy for adult asthma.
METHODS
We searched randomized controlled trials from MEDLINE via the PubMed, CENTRAL, and Ichushi Web databases. The primary outcome was asthma exacerbation. The secondary outcomes were serious adverse events (including mortality), asthma-related quality of life (symptom scales, Asthma Control Questionnaire, and Asthma Quality of Life Questionnaire), rescue medication (puffs/day), respiratory function (morning peak expiratory flow, evening peak flow, and forced expiratory volume in 1 s), bronchial hyperresponsiveness, and minimum oral corticosteroid dose. Of the 805 studies, we selected seven studies for the meta-analysis, which was conducted using a random-effects model.
SYSTEMATIC REVIEW REGISTRATION
University Hospital Medical Information Network Clinical Trials Registry (UMIN000050824).
RESULTS
No significant difference between macrolide and placebo for asthma exacerbations was observed (risk ratio 0.71, 95 % confidence interval [CI] 0.46-1.09; p = 0.12). Macrolide therapy for adult asthma showed a significant improvement in rescue medication with short-acting beta-agonists (mean difference -0.41, 95 % CI -0.78 to -0.04; p = 0.03). Macrolide therapy did not show more serious adverse events (odd ratio 0.61, 95 % CI 0.34-1.10; p = 0.10) than those with placebo. The other secondary outcomes were not significantly different between the macrolide and placebo groups.
CONCLUSIONS
Macrolide therapy for adult asthma may be more effective than placebo and could be a treatment option.
Topics: Adult; Humans; Macrolides; Quality of Life; Disease Progression; Asthma; Anti-Bacterial Agents; Adrenal Cortex Hormones
PubMed: 38211545
DOI: 10.1016/j.resinv.2023.12.015 -
The Lancet. Microbe Jun 2024
Topics: Humans; China; Pneumonia, Mycoplasma; Macrolides; Mycoplasma pneumoniae; Anti-Bacterial Agents; Drug Resistance, Bacterial
PubMed: 38244553
DOI: 10.1016/S2666-5247(23)00405-6 -
Chest Jan 2024There are several antibiotic regimens to treat community-acquired pneumonia (CAP). (Clinical Trial)
Clinical Trial
Comparative Effectiveness of First-Line and Alternative Antibiotic Regimens in Hospitalized Patients With Nonsevere Community-Acquired Pneumonia: A Multicenter Retrospective Cohort Study.
BACKGROUND
There are several antibiotic regimens to treat community-acquired pneumonia (CAP).
RESEARCH QUESTION
In patients hospitalized to a non-ICU ward setting with CAP, is there a difference between first-line and alternative antibiotic regimens (β-lactam plus macrolide [BL+M], β-lactam [BL] alone, respiratory fluoroquinolone [FQ], or β-lactam plus doxycycline [BL+D]) in terms of in-hospital mortality?
STUDY DESIGN AND METHODS
This retrospective cohort study included consecutive patients admitted with CAP at 19 Canadian hospitals from 2015 to 2021. Taking a target trial approach, patients were categorized into the four antibiotic groups based on the initial antibiotic treatment within 48 h of admission. Patients with severe CAP requiring ICU admission in the first 48 h were excluded. The primary outcome was all-cause in-hospital mortality. Secondary outcome included time to being discharged alive. Propensity score and overlap weighting were used to balance covariates.
RESULTS
Of 23,512 patients, 9,340 patients (39.7%) received BL+M, 9,146 (38.9%) received BL, 4,510 (19.2%) received FQ, and 516 (2.2%) received BL+D. The number of in-hospital deaths was 703 (7.5%) for the BL+M group, 888 (9.7%) for the BL group, 302 (6.7%) for the FQ group, and 31 (6.0%) for the BL+D group. The adjusted risk difference for in-hospital mortality when compared with BL+M was 1.5% (95% CI, -0.3% to 3.3%) for BL, -0.9% (95% CI, -2.9% to 1.1%) for FQ, and -1.9% (95% CI, -4.8% to 0.9%) for BL+D. Compared with BL+M, the subdistribution hazard ratio for being discharged alive was 0.90 (95% CI, 0.84-0.96) for BL, 1.07 (95% CI, 0.99-1.16) for FQ, and 1.04 (95% CI, 0.93-1.17) for BL+D.
INTERPRETATION
BL+M, FQ, and BL+D had similar outcomes and can be considered effective regimens for nonsevere CAP. Compared with BL+M, BL was associated with longer time to discharge and the CI for mortality cannot exclude a small but clinically important increase in risk.
Topics: Humans; Anti-Bacterial Agents; beta-Lactams; Canada; Community-Acquired Infections; Drug Therapy, Combination; Length of Stay; Macrolides; Pneumonia; Retrospective Studies
PubMed: 37574164
DOI: 10.1016/j.chest.2023.08.008 -
Clinical Infectious Diseases : An... Nov 2023Mycoplasma genitalium (MG) is on the CDC Watch List of Antimicrobial Resistance Threats, yet there is no systematic surveillance to monitor change.
BACKGROUND
Mycoplasma genitalium (MG) is on the CDC Watch List of Antimicrobial Resistance Threats, yet there is no systematic surveillance to monitor change.
METHODS
We initiated surveillance in sexual health clinics in 6 cities, selecting a quota sample of urogenital specimens tested for gonorrhea and/or chlamydia. We abstracted patient data from medical records and detected MG and macrolide-resistance mutations (MRMs) by nucleic acid amplification testing. We used Poisson regression to estimate adjusted prevalence ratios (aPRs) and 95% CIs, adjusting for sampling criteria (site, birth sex, symptom status).
RESULTS
From October-December 2020 we tested 1743 urogenital specimens: 57.0% from males, 46.1% from non-Hispanic Black persons, and 43.8% from symptomatic patients. MG prevalence was 16.6% (95% CI: 14.9-18.5%; site-specific range: 9.9-23.5%) and higher in St Louis (aPR: 1.9; 1.27-2.85), Greensboro (aPR: 1.8; 1.18-2.79), and Denver (aPR: 1.7; 1.12-2.44) than Seattle. Prevalence was highest in persons <18 years (30.4%) and declined 3% per each additional year of age (aPR: .97; .955-.982). MG was detected in 26.8%, 21.1%, 11.8%, and 15.4% of urethritis, vaginitis, cervicitis, and pelvic inflammatory disease (PID), respectively. It was present in 9% of asymptomatic males and 15.4% of asymptomatic females, and associated with male urethritis (aPR: 1.7; 1.22-2.50) and chlamydia (aPR: 1.7; 1.13-2.53). MRM prevalence was 59.1% (95% CI: 53.1-64.8%; site-specific range: 51.3-70.6%). MRMs were associated with vaginitis (aPR: 1.8; 1.14-2.85), cervicitis (aPR: 3.5; 1.69-7.30), and PID cervicitis (aPR: 1.8; 1.09-3.08).
CONCLUSIONS
MG infection is common in persons at high risk of sexually transmitted infections; testing symptomatic patients would facilitate appropriate therapy. Macrolide resistance is high and azithromycin should not be used without resistance testing.
Topics: Female; Humans; Male; Anti-Bacterial Agents; Urethritis; Mycoplasma genitalium; Uterine Cervicitis; Sexual Health; Macrolides; Drug Resistance, Bacterial; Pelvic Inflammatory Disease; Vaginitis; Mycoplasma Infections; Prevalence
PubMed: 37402645
DOI: 10.1093/cid/ciad405 -
Indian Journal of Medical Microbiology 2023As a major causative pathogen of community-acquired pneumonia, Mycoplasma pneumoniae (M. pneumoniae) can cause both upper and lower respiratory tract inflammation as...
BACKGROUND/PURPOSE
As a major causative pathogen of community-acquired pneumonia, Mycoplasma pneumoniae (M. pneumoniae) can cause both upper and lower respiratory tract inflammation as well as extrapulmonary syndromes, especially in infants and the elderly. The emergence of macrolide-resistance has significant effects on the treatment of relevant diseases in children. This study aimed to analyze the genotypes and the macrolide resistance-associated mutations in M. pneumoniae sampled from the pediatric patients in Henan, China.
METHODS
A segment of gene on the 23S rRNA was amplified and sequenced to detect the mutations related to macrolide resistance. Molecular typing was performed by the method named multiple locus variable-number tandem repeat analysis (MLVA) for macrolide-susceptible and macrolide-resistant specimens.
RESULTS
Among the M. pneumoniae-positive samples, 95.7% (111/116) had macrolide-resistant mutation, and all of them consisted of the A2063G mutation. There were only two MLVA types identified in this study, type 4-5-7-2 (51/92, 55.4%) and type 3-5-6-2 (41/92, 44.6%).
CONCLUSION
There was no correlation between MLVA types and macrolide resistance (P > 0.05).
Topics: Infant; Humans; Child; Aged; Mycoplasma pneumoniae; Anti-Bacterial Agents; Pneumonia, Mycoplasma; Macrolides; Drug Resistance, Bacterial; Molecular Typing; China
PubMed: 37945129
DOI: 10.1016/j.ijmmb.2023.100435 -
Frontiers in Cellular and Infection... 2023Traditional drug susceptibility testing cannot be performed in clinical laboratories due to the slow-growing characteristics of when cultured . Sanger sequencing is the...
BACKGROUND
Traditional drug susceptibility testing cannot be performed in clinical laboratories due to the slow-growing characteristics of when cultured . Sanger sequencing is the standard method for detecting drug resistance-associated mutations. It has been used in some laboratories to guide the choice of macrolide antibiotics for infected patients. Furthermore, resistance to fluoroquinolone has become another emerging clinical challenge.
OBJECTIVE
Sequencing analysis can detect unknown mutations, but it is time-consuming, requires professional analytical skills and the appropriate testing equipment. The main objective of this study was to establish a nested real-time PCR method for the simultaneous detection of and genotypes in relation to the macrolide and fluoroquinolone resistance.
RESULTS
105 MG-positive samples and 27 samples containing other pathogens were used for validation. The limit of the nested real-time PCR detection was 500 copies/reaction and there was no cross-reaction with , , , , , , and , but the assay cross-reacted with . Compared with sequencing results, the sensitivity of was 100% (95% CI; 93.3 -100), the specificity was 94.3% (95% CI; 79.4 - 99.0), the overall consistency was 98% (95% CI; 92.5 - 99.7) and value was 0.96 ( < 0.001); the sensitivity of was 100% (95% CI; 93.4 - 100), the specificity was 89.7% (95% CI; 71.5 - 97.3) and the overall consistency was 96.9% (95% CI; 90.7 - 99.2) with a value of 0.92 ( < 0.001).
CONCLUSIONS
The results of this sensitive and rapid alternative for identifying resistant genotypes of are intuitive and easy to interpret, especially for mixed MG populations. Although the relevant primers need further adjustment, this reliable method would provide an effective diagnostic tool for the selection of antibiotics in clinical practice.
Topics: Humans; Fluoroquinolones; Mycoplasma genitalium; RNA, Ribosomal, 23S; Real-Time Polymerase Chain Reaction; Macrolides; Microbial Sensitivity Tests; Drug Resistance, Bacterial; Mycoplasma Infections; Mycobacterium tuberculosis; Anti-Bacterial Agents; Mutation
PubMed: 37928183
DOI: 10.3389/fcimb.2023.1271392 -
European Journal of Pediatrics Jul 2024Mycoplasma pneumoniae (MP) is an important cause of community-acquired pneumonia in children and young adolescents. Despite macrolide antibiotics effectiveness as a... (Review)
Review
UNLABELLED
Mycoplasma pneumoniae (MP) is an important cause of community-acquired pneumonia in children and young adolescents. Despite macrolide antibiotics effectiveness as a first-line therapy, persistence of fever and/or clinical deterioration sometimes may complicate treatment and may even lead to severe systemic disease. To date, there is no consensus on alternative treatment options, optimal dosage, and duration for treating severe, progressive, and systemic MP pneumonia after macrolide treatment failure. Macrolide-resistant MP pneumonia and refractory MP pneumonia are the two major complex conditions that are clinically encountered. Currently, the vast majority of MP isolates are resistant to macrolides in East Asia, especially China, whereas in Europe and North America, whereas in Europe and North America prevalence is substantially lower than in Asia, varying across countries. The severity of pneumonia and extrapulmonary presentations may reflect the intensity of the host's immune reaction or the dissemination of bacterial infection. Children infected with macrolide-resistant MP strains who receive macrolide treatment experience persistent fever with extended antibiotic therapy and minimal decrease in MP-DNA load. Alternative second-line agents such as tetracyclines (doxycycline or minocycline) and fluoroquinolones (ciprofloxacin or levofloxacin) may lead to clinical improvement after macrolide treatment failure in children. Refractory MP pneumonia reflects a deterioration of clinical and radiological findings due to excessive immune response against the infection. Immunomodulators such as corticosteroids and intravenous immunoglobulin (IVIG) have shown promising results in treatment of refractory MP pneumonia, particularly when combined with appropriate antimicrobials. Corticosteroid-resistant hyperinflammatory MP pneumonia represents a persistent or recrudescent fever despite corticosteroid therapy with intravenous methylprednisolone at standard dosage.
CONCLUSION
This report summarizes the clinical significance of macrolide-resistant and refractory MP pneumonia and discusses the efficacy and safety of alternative drugs, with a stepwise approach to the management of MP pneumonia recommended from the viewpoint of clinical practice.
WHAT IS KNOWN
• Although MP pneumonia is usually a benign self-limited infection with response macrolides as first line therapy, severe life-threatening cases may develop if additional treatment strategies are not effectively implemented. • Macrolide-resistant and refractory MP pneumonia are two conditions that may complicate the clinical course of MP pneumonia, increasing the risk for exacerbation and even death.
WHAT IS NEW
• This report summarizes the clinical relevance of macrolide-resistant and refractory MP pneumonia and discusses the efficacy and safety of alternative drug therapies. • A practical stepwise approach to the management of MP pneumonia is developed based on a comprehensive analysis of existing evidence and expert opinion.
Topics: Humans; Pneumonia, Mycoplasma; Anti-Bacterial Agents; Child; Macrolides; Mycoplasma pneumoniae; Drug Resistance, Bacterial; Community-Acquired Infections; Adolescent
PubMed: 38634891
DOI: 10.1007/s00431-024-05519-1 -
Otolaryngology--head and Neck Surgery :... Dec 2023To evaluate the efficacy and safety of macrolide antibiotics therapy in patients with chronic rhinosinusitis (CRS) receiving endoscopic sinus surgery. (Meta-Analysis)
Meta-Analysis Review
OBJECTIVES
To evaluate the efficacy and safety of macrolide antibiotics therapy in patients with chronic rhinosinusitis (CRS) receiving endoscopic sinus surgery.
DATA SOURCES
PubMed, Web of Science, Embase, and Cochrane Library.
REVIEW METHODS
The electronic databases were comprehensively searched on June 2, 2022, for randomized controlled trials on macrolide antibiotics in the treatment of patients undergoing CRS endoscopic surgery. The primary outcome measures were the sinonasal outcome test (SNOT) score and the visual analog scale (VAS) score. The secondary outcome measures were the nasal endoscopy score (NES), the sinus computed tomography score, and adverse events.
RESULTS
A total of 8 studies were included, involving 606 patients who used macrolide for a long time. Meta-analysis showed that no significant difference was observed in SNOT (standardized mean difference [SMD] = -0.13; 95% confidence interval [CI]: -0.38 to 0.13, I = 0%) and VAS (SMD = -0.10; 95% CI, -0.88 to 0.68, I = 81%) between the macrolide and placebo groups. However, macrolide outperformed the placebo in improving NES (SMD = -0.32; 95% CI, -0.62 to -0.03, I = 21%). The use of macrolide did not increase the incidence of adverse events.
CONCLUSION
Long-term use of macrolide after CRS surgery may not significantly improve the quality of life and disease severity of the patients but may play a role in improving postoperative NES in patients with CRS. There is still no sufficient evidence to determine whether the disease phenotype of CRS or the patient's race will affect the efficacy of long-term use of macrolide after CRS.
Topics: Humans; Macrolides; Quality of Life; Rhinitis; Nasal Polyps; Sinusitis; Anti-Bacterial Agents; Chronic Disease; Endoscopy
PubMed: 37548067
DOI: 10.1002/ohn.461 -
The Lancet. Microbe Dec 2023The increasing incidence of syphilis and the limitations of first-line treatment with penicillin, particularly in neurosyphilis, neonatal syphilis, and pregnancy,...
BACKGROUND
The increasing incidence of syphilis and the limitations of first-line treatment with penicillin, particularly in neurosyphilis, neonatal syphilis, and pregnancy, highlight the need to expand the therapeutic repertoire for effective management of this disease. We assessed the in-vitro efficacy of 18 antibiotics from several classes on Treponema pallidum subspecies pallidum (T pallidum), the syphilis bacteria.
METHODS
Using the in-vitro culture system for T pallidum, we exposed the pathogen to a concentration range of each tested antibiotic. After a 7-day incubation, the treponemal burden was evaluated by quantitative PCR targeting the T pallidum tp0574 gene. The primary outcome was the minimum inhibitory concentration (MIC) at which the quantitative PCR values were not significantly higher than the inoculum wells. We also investigated the susceptibility of macrolide-resistant strains to high concentrations of azithromycin, and the possibility of developing resistance to linezolid, a proposed candidate for syphilis treatment.
FINDINGS
Amoxicillin, ceftriaxone, several oral cephalosporins, tedizolid, and dalbavancin exhibited anti-treponemal activity at concentrations achievable in human plasma following regular dosing regimens. The experiments revealed a MIC for amoxicillin at 0·02 mg/L, ceftriaxone at 0·0025 mg/L, cephalexin at 0·25 mg/L, cefetamet and cefixime at 0·0313 mg/L, cefuroxime at 0·0156 mg/L, tedizolid at 0·0625 mg/L, spectinomycin at 0·1 mg/L, and dalbavancin at 0·125 mg/L. The MIC for zoliflodacin and balofloxacin was 2 mg/L. Ertapenem, isoniazid, pyrazinamide, and metronidazole had either a poor or no effect. Azithromycin concentrations up to 2 mg/L (64 times the MIC) were ineffective against strains carrying mutations associated to macrolide resistance. Exposure to subtherapeutic doses of linezolid for 10 weeks did not induce phenotypic or genotypic resistance.
INTERPRETATION
Cephalosporins and oxazolidinones are potential candidates for expanding the current therapeutic repertoire for syphilis. Our findings warrant testing efficacy in animal models and, if successful, clinical assessment of efficacy.
FUNDING
European Research Council.
Topics: Animals; Infant, Newborn; Humans; Treponema pallidum; Anti-Bacterial Agents; Azithromycin; Syphilis; Macrolides; Linezolid; Ceftriaxone; Globus Pallidus; Drug Resistance, Bacterial; Amoxicillin; Treponema
PubMed: 37827185
DOI: 10.1016/S2666-5247(23)00219-7