The Staphylococcus aureus CC398 Lineage: An Evolution Driven by the Acquisition of Prophages and Other Mobile Genetic Elements.

Floriane Laumay,Anna-Rita Corvaglia,Hugo Benchetrit,Patrice François,Nathalie Van Der Mee-Marquet

doi:10.3390/genes12111752

Abstract

Among clinically relevant lineages of Staphylococcus aureus, the lineage or clonal complex 398 (CC398) is of particular interest. Strains from this lineage were only described as livestock colonizers until 2007. Progressively, cases of infection were reported in humans in contact with farm animals, and now, CC398 isolates are increasingly identified as the cause of severe infections even in patients without any contact with animals. These observations suggest that CC398 isolates have spread not only in the community but also in the hospital setting. In addition, several recent studies have reported that CC398 strains are evolving towards increased virulence and antibiotic resistance. Identification of the origin and emergence of this clonal complex could probably benefit future large-scale studies that aim to detect sources of contamination and infection. Current evidence indicates that the evolution of CC398 strains towards these phenotypes has been driven by the acquisition of prophages and other mobile genetic elements. In this short review, we summarize the main knowledge of this major lineage of S. aureus that has become predominant in the human clinic worldwide within a single decade.

Highlights

Staphylococcus aureus is a ubiquitous human and veterinary pathogen recognized as a worldwide health problem
The authors of the study aimed to characterize community clones of methicillin-resistant S. aureus (MRSA) that emerged in a few individuals involved with pig farming and that were nontypable by pulsed-field gel electrophoresis
Another important study on almost 1000 cases of bone and joint infections associated with S. aureus, collected over an 8-year period, showed that the prevalence of clonal complex 398 (CC398) has increased from 4% in 2010 to 26% in 2017, and that the majority of isolates was sensitive to methicillin [46]

Summary

Introduction

Staphylococcus aureus is a ubiquitous human and veterinary pathogen recognized as a worldwide health problem. The authors of the study aimed to characterize community clones of methicillin-resistant S. aureus (MRSA) that emerged in a few individuals involved with pig farming and that were nontypable by pulsed-field gel electrophoresis. These clones increased in proportion from 0% in 2002 to more than 20% of MRSA, in the Netherlands, in 2006. Recent studies show that the lineage continues to evolve in terms of virulence and resistance [26,27], and there is increased evidence that isolates have, during the last decade, acquired genetic features contributing to host adaptation and virulence through integration of prophages [28,29]. The purpose of this short review is to present the main studies of evolution of the S. aureus lineage 398 and its prophages and other MGE acquisitions, and our current understanding of these phenomena at the molecular level

Clinical Importance of the CC398 Lineage

Roles of CC398-Borne Prophages in Bacterial Virulence

Findings

Conclusions