Article

In vitro production of panton-valentine leukocidin among strains of methicillin-resistant Staphylococcus aureus causing diverse infections.

Veterans Affairs Medical Center, Boise, Idaho 83702, USA.
Clinical Infectious Diseases (impact factor: 9.15). 01/2008; 45(12):1550-8. DOI:10.1086/523581
Source: PubMed

ABSTRACT Community-acquired methicillin-resistant Staphylococcus aureus strains have recently been associated with severe necrotizing infections. Greater than 75% of these strains carry the genes for Panton-Valentine leukocidin (PVL), suggesting that this toxin may mediate these severe infections. However, to date, studies have not provided evidence of toxin production.
Twenty-nine community-acquired methicillin-resistant Staphylococcus aureus and 2 community-acquired methicillin-susceptible S. aureus strains were collected from patients with infections of varying severity. Strains were analyzed for the presence of lukF-PV and SCCmecA type. PVL production in lukF-PV gene-positive strains was measured by ELISA, and the amount produced was analyzed relative to severity of infection.
Only 2 of the 31 strains tested, 1 methicillin-resistant Staphylococcus aureus abscess isolate and 1 nasal carriage methicillin-susceptible S. aureus isolate, were lukF-PV negative. All methicillin-resistant Staphylococcus aureus strains were SCCmec type IV. PVL was produced by all strains harboring lukF-PV, although a marked strain-to-strain variation was observed. Twenty-six (90%) of 29 strains produced 50-350 ng/mL of PVL; the remaining strains produced PVL in excess of 500 ng/mL. The quantity of PVL produced in vitro did not correlate with severity of infection.
Although PVL likely plays an important role in the pathogenesis of these infections, its mere presence is not solely responsible for the increased severity. Factors that up-regulate toxin synthesis in vivo could contribute to more-severe disease and worse outcomes in patients with community-acquired methicillin-resistant Staphylococcus aureus infection.

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Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.

Keywords

1 nasal carriage methicillin-susceptible S. aureus
 
2 community-acquired methicillin-susceptible S. aureus strains
 
29 strains
 
31 strains
 
community-acquired methicillin-resistant Staphylococcus aureus
 
community-acquired methicillin-resistant Staphylococcus aureus infection
 
Community-acquired methicillin-resistant Staphylococcus aureus strains
 
increased severity
 
lukF-PV gene-positive strains
 
marked strain-to-strain variation
 
mere presence
 
methicillin-resistant Staphylococcus aureus strains
 
PVL production
 
remaining strains
 
severe infections
 
severe necrotizing infections
 
strains harboring lukF-PV
 
toxin production
 
up-regulate toxin synthesis
 
varying severity