Ultrastructural, metabolic and genetic characteristics of determinants facilitating the acquisition of macrolide resistance by Streptococcus pneumoniae
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引用次数: 0
Abstract
Aims
To investigate the molecular events associated with acquiring macrolide resistance genes [mefE/mel (Mega) or ermB] in Streptococcus pneumoniae (Spn) during nasopharyngeal colonization.
Methods and results
Genomic analysis of 128 macrolide-resistant Spn isolates revealed recombination events in genes of the conjugation apparatus, or the competence system, in strains carrying Tn916-related elements. Studies using confocal and electron microscopy demonstrated that during the transfer of Tn916-related elements in nasopharyngeal cell biofilms, pneumococcal strains formed clusters facilitating their acquisition of resistance determinants at a high recombination frequency (rF). Remarkably, these aggregates comprise both encapsulated and nonencapsulated pneumococci that span extracellular and intracellular compartments. rF assessments showed similar rates regardless Mega was associated with large integrative and conjugative elements (ICEs) (>23 kb) or not (∼5.4 kb). The rF for Mega Class IV(c) insertion region (∼53 kb) was three orders of magnitude higher than the transformation of the capsule locus. Metabolomics studies of the microenvironment created by colonization of human nasopharyngeal cells revealed a link between the acquisition of ICEs and the pathways involving nicotinic acid and sucrose.
Conclusions
Pneumococcal clusters, both extracellular and intracellular, facilitate macrolide resistance acquisition, and ICEs were acquired at a higher frequency than the capsule locus. Metabolic changes could serve as intervention targets.
期刊介绍:
Drug Resistance Updates serves as a platform for publishing original research, commentary, and expert reviews on significant advancements in drug resistance related to infectious diseases and cancer. It encompasses diverse disciplines such as molecular biology, biochemistry, cell biology, pharmacology, microbiology, preclinical therapeutics, oncology, and clinical medicine. The journal addresses both basic research and clinical aspects of drug resistance, providing insights into novel drugs and strategies to overcome resistance. Original research articles are welcomed, and review articles are authored by leaders in the field by invitation.
Articles are written by leaders in the field, in response to an invitation from the Editors, and are peer-reviewed prior to publication. Articles are clear, readable, and up-to-date, suitable for a multidisciplinary readership and include schematic diagrams and other illustrations conveying the major points of the article. The goal is to highlight recent areas of growth and put them in perspective.
*Expert reviews in clinical and basic drug resistance research in oncology and infectious disease
*Describes emerging technologies and therapies, particularly those that overcome drug resistance
*Emphasises common themes in microbial and cancer research