Uhlemann_2012_MBio_3_e00027

Reference

Title : Identification of a highly transmissible animal-independent Staphylococcus aureus ST398 clone with distinct genomic and cell adhesion properties - Uhlemann_2012_MBio_3_e00027
Author(s) : Uhlemann AC , Porcella SF , Trivedi S , Sullivan SB , Hafer C , Kennedy AD , Barbian KD , McCarthy AJ , Street C , Hirschberg DL , Lipkin WI , Lindsay JA , Deleo FR , Lowy FD
Ref : MBio , 3 : , 2012
Abstract :

A methicillin-resistant Staphylococcus aureus (MRSA) clone known as ST398 has emerged as a major cause of acute infections in individuals who have close contact with livestock. More recently, the emergence of an animal-independent ST398 methicillin-sensitive S. aureus (MSSA) clone has been documented in several countries. However, the limited surveillance of MSSA has precluded an accurate assessment of the global spread of ST398 and its clinical relevance. Here we provide evidence that ST398 is a frequent source of MSSA infections in northern Manhattan and is readily transmitted between individuals in households. This contrasts with the limited transmissibility of livestock-associated ST398 (LA-ST398) MRSA strains between humans. Our whole-genome sequence analysis revealed that the chromosome of the human-associated ST398 MSSA clone is smaller than that of the LA-ST398 MRSA reference strain S0385, due mainly to fewer mobile genetic elements (MGEs). In contrast, human ST398 MSSA isolates harbored the prophage varphi3 and the human-specific immune evasion cluster (IEC) genes chp and scn. While most of the core genome was conserved between the human ST398 MSSA clone and S0385, these strains differed substantially in their repertoire and composition of intact adhesion genes. These genetic changes were associated with significantly enhanced adhesion of human ST398 MSSA isolates to human skin keratinocytes and keratin. We propose that the human ST398 MSSA clone can spread independent of animal contact using an optimized repertoire of MGEs and adhesion molecules adapted to transmission among humans. IMPORTANCE: Staphylococcus aureus strains have generally been considered to be species specific. However, cross-species transfers of S. aureus clones, such as ST398 methicillin-resistant S. aureus (MRSA), from swine to humans have been reported. Recently, we observed the emergence of ST398 methicillin-susceptible S. aureus (MSSA) as a colonizing strain of humans in northern Manhattan. Here we report that ST398 is a frequent cause of MSSA infections in this urban setting. The ST398 MSSA clone was readily transmitted within households, independent of animal contact. We discovered that human ST398 MSSA genomes were smaller than that of the LA-ST398 strain S0385 due to fewer mobile genetic elements. Human and LA-ST398 strains also differed in their composition of adhesion genes and their ability to bind to human skin keratinocytes, providing a potential mechanism of S. aureus host adaptation. Our findings illustrate the importance of implementing molecular surveillance of MSSA given the evidence for the rapid and clinically undetected spread of ST398 MSSA.

PubMedSearch : Uhlemann_2012_MBio_3_e00027
PubMedID: 22375071
Gene_locus related to this paper: staau-SA0897 , staau-SA2240 , staa8-asp2

Related information

Gene_locus staau-SA0897    staau-SA2240    staa8-asp2

Citations formats

Uhlemann AC, Porcella SF, Trivedi S, Sullivan SB, Hafer C, Kennedy AD, Barbian KD, McCarthy AJ, Street C, Hirschberg DL, Lipkin WI, Lindsay JA, Deleo FR, Lowy FD (2012)
Identification of a highly transmissible animal-independent Staphylococcus aureus ST398 clone with distinct genomic and cell adhesion properties
MBio 3 :

Uhlemann AC, Porcella SF, Trivedi S, Sullivan SB, Hafer C, Kennedy AD, Barbian KD, McCarthy AJ, Street C, Hirschberg DL, Lipkin WI, Lindsay JA, Deleo FR, Lowy FD (2012)
MBio 3 :