Demography and Intercontinental Spread of the USA300 Community-Acquired Methicillin-Resistant Staphylococcus aureus Lineage

Abstract

Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) was recognized worldwide during the 1990s; in less than a decade, several genetically distinct CA-MRSA lineages carrying Panton-Valentine leukocidin genes have emerged on every continent. Most notably, in the United States, the sequence type 18-IV (ST8-IV) clone known as USA300 has become highly prevalent, outcompeting methicillin-susceptible S. aureus (MSSA) and other MRSA strains in both community and hospital settings. CA-MRSA bacteria are much less prevalent in Europe, where the European ST80-IV European CA-MRSA clone, USA300 CA-MRSA strains, and other lineages, such as ST22-IV, coexist. The question that arises is whether the USA300 CA-MRSA present in Europe (i) was imported once or on very few occasions, followed by a broad geographic spread, anticipating an increased prevalence in the future, or (ii) derived from multiple importations with limited spreading success. In the present study, we applied whole-genome sequencing to a collection of French USA300 CA-MRSA strains responsible for sporadic cases and micro-outbreaks over the past decade and United States ST8 MSSA and MRSA isolates. Genome-wide phylogenetic analysis demonstrated that the population structure of the French isolates is the product of multiple introductions dating back to the onset of the USA300 CA-MRSA clone in North America. Coalescent-based demography of the USA300 lineage shows that a strong expansion occurred during the 1990s concomitant with the acquisition of the arginine catabolic mobile element and antibiotic resistance, followed by a sharp decline initiated around 2008, reminiscent of the rise-and-fall pattern previously observed in the ST80 lineage. A future expansion of the USA300 lineage in Europe is therefore very unlikely.

Complete-genome sequencing elucidates outbreak dynamics of CA-MRSA USA300 (ST8-spa t008) in an academic hospital of Paramaribo, Republic of Suriname

“…The isolates recovered in Suriname carried the ACME element characteristic for the USA300-NA clade28. The isolates analyzed in this study also showed fluoroquinolone-resistance with the same mutations in grlA (S80Y) and gyrA (S84L) (Table 2) like those found in the USA300-NA clade, which has spread globally10. Moreover, all isolates from Suriname carried pUSA04 plasmid related to plasmid pUSA300HOUMR found in USA300 isolates recovered from patients in the United States.…”

“…To date analysis of complete genomes has the ultimate resolution power enabling the detection of single point mutations (single nucleotide polymorphisms, SNPs) as well as the presence or absence of mobile genetic elements and genomic data have become increasingly available for identification of bacterial transmission between patients during outbreak investigations10111213141516. In this study, we obtained complete genome sequences of 24 MRSA isolates recovered from patients during an outbreak in an academic hospital in Paramaribo in the Republic of Suriname.…”

Genomic insights into the emergence and spread of international clones of healthcare-, community- and livestock-associated meticillin-resistant Staphylococcus aureus : Blurring of the traditional definitions

“…The expansion of USA300 in Europe may have occurred as a single point introduction followed by spread, or by multiple introductions over a long period of time followed by limited spread on each occasion. WGS data on the French isolates reveal that following multiple introductions, the lineage has stabilised and may even decline [49].…”

Thermally triggered release of the bacteriophage endolysin CHAPK and the bacteriocin lysostaphin for the control of methicillin resistant Staphylococcus aureus (MRSA)

“…Furthermore, the isolation of these ‘super-bugs’ is not confined to the hospital setting. Indeed, community acquired MRSA (CA-MRSA) is proving an equal challenge to clinicians worldwide [4].…”