The interplay between mobilome and resistome in Staphylococcus aureus

Area of Science:

• Microbiology
• Genomics
• Antimicrobial Resistance

Background:

• Antibiotic resistance genes (ARGs) in Staphylococcus aureus can spread through clonal expansion and horizontal gene transfer via mobile genetic elements (MGEs).
• The association between MGEs and ARGs in S. aureus contributes to the emergence of multidrug-resistant (MDR) strains, posing significant challenges in human and animal health.
• Understanding the interplay between the mobilome and resistome is crucial for addressing the growing threat of antibiotic resistance.

Purpose of the Study:

• To investigate the intricate relationship between MGEs and ARGs in a large dataset of S. aureus genomes from human and animal origins.
• To identify the primary MGEs involved in ARG dissemination and analyze their associations.
• To compare MGE/ARG associations across different host origins and sequence types (STs) to understand spread dynamics.

Main Methods:

• Genomic analysis of over 10,000 S. aureus genomes from human and animal sources.
• Identification and characterization of mobile genetic elements (MGEs) and antibiotic resistance genes (ARGs).
• Comparative analysis of MGE/ARG associations across different isolates, STs, and host origins.

Main Results:

• A wide diversity of MGEs and ARGs was observed, with plasmids and transposons identified as major ARG carriers.
• Numerous MGE/ARG associations were found, underscoring the critical role of MGEs in resistance dissemination.
• Significant similarities in MGE/ARG associations between human and animal isolates suggest unrestricted ARG spread between hosts and across different STs.

Conclusions:

• Mobile genetic elements play a pivotal role in shaping the S. aureus resistome, facilitating the spread of antibiotic resistance beyond clonal lineages.
• The observed similarities in MGE/ARG associations across hosts highlight the potential for rapid dissemination of multidrug resistance.
• Further research into the mechanisms governing MGE spread and ARG transfer is essential for developing effective strategies against MDR S. aureus.