Comparative analysis of virulence and toxin expression of global community-associated methicillin-resistant Staphylococcus aureus strains.
The current pandemic of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) skin infections is caused by several genetically unrelated clones. Here, we analyzed virulence of globally occurring CA-MRSA strains in a rabbit skin infection model. We used rabbits because neutrophils from this animal species have relatively high sensitivity to Panton-Valentine leukocidin (PVL), a toxin epidemiologically correlated with many CA-MRSA infections. Virulence in the rabbit model correlated with in vitro neutrophil lysis and transcript levels of phenol-soluble modulin α and α-toxin, but not PVL genes. Furthermore, abscesses caused by USA300 and its PVL-negative progenitor USA500 were comparatively large and similar in size, suggesting that PVL has played a limited role in the evolution of USA300 virulence in the context of skin infections. Our study indicates a major but not exclusive impact of virulence on the epidemiological success of USA300 and other CA-MRSA strains and emphasizes the importance of core genome-encoded toxins in CA-MRSA skin infections.
Department of Laboratory Medicine, Huashan Hospital, Shanghai 200040, People’s Republic of China.
Min
M
Li
Gordon Y C
GY
Cheung
Jinhui
J
Hu
Decheng
D
Wang
Hwang-Soo
HS
Joo
Frank R
FR
Deleo
Michael
M
Otto
D000818:Animals; D001427:Bacterial Toxins / Q000096:biosynthesis*; D017714:Community-Acquired Infections / Q000382:microbiology*; D004195:Disease Models, Animal; D005098:Exotoxins / Q000096:biosynthesis; D005260:Female; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D006460:Hemolysin Proteins / Q000096:biosynthesis*; D007956:Leukocidins / Q000096:biosynthesis; D055624:Methicillin-Resistant Staphylococcus aureus / Q000472:pathogenicity*; D009504:Neutrophils / Q000382:microbiology; D011817:Rabbits; D012867:Skin / Q000382:microbiology / Q000473:pathology; D013207:Staphylococcal Skin Infections / Q000382:microbiology*; D014774:Virulence; D037521:Virulence Factors / Q000096:biosynthesis*
D001427:Bacterial Toxins; D005098:Exotoxins; D006460:Hemolysin Proteins; D007956:Leukocidins; C078284:Panton-Valentine leukocidin; D037521:Virulence Factors; C021091:staphylococcal alpha-toxin; C025971:staphylococcal delta toxin