Panton-Valentine leukocidin genes are associated with enhanced inflammatory response and local disease in acute hematogenous Staphylococcus aureus osteomyelitis in children.
BACKGROUND
Staphylococcus aureus strains carrying the genes encoding Panton-Valentine leukocidin (pvl-positive [pvl+]) are associated with more febrile days and higher complication rates of osteomyelitis in children than are pvl-negative (pvl-) strains.


OBJECTIVE
Selected clinical, laboratory, and radiographic findings in children with osteomyelitis caused by pvl+ and pvl- S aureus strains were compared.


METHODS
The demographics, selected clinical features, laboratory values, and radiographic findings of children with community-acquired S aureus osteomyelitis prospectively identified at Texas Children's Hospital between August 2001 and July 2004 were reviewed. Polymerase chain reaction was performed to detect the genes for pvl (luk-S-PV and luk-F-PV) and fibronectin-binding protein (fnbB) in S aureus isolates. Chi2, 2-sample t test, and multiple logistic regression were used for statistical analysis.


RESULTS
Methicillin-susceptible and methicillin-resistant S aureus (MSSA and MRSA, respectively) caused osteomyelitis in 33 and 56 children, respectively. Twenty-six isolates were pvl- (26 MSSA), 59 were pvl+ (3 MSSA, 56 MRSA), and 4 were not available for analysis (4 MSSA). On univariate analysis, patients with pvl+ S aureus isolates had significantly higher erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) level both at presentation and as a maximum value during hospitalization and were more likely to have a blood culture positive for S aureus during their admission. Patients with pvl+ S aureus isolates were significantly more likely to have concomitant myositis or pyomyositis compared with patients with pvl- S aureus isolates on MRI. In a multivariate analysis pvl remained significantly associated with ESR and CRP levels at presentation and blood culture positive for S aureus. pvl+ status and younger age were associated with myositis on MRI.


CONCLUSIONS
Osteomyelitis caused by pvl+ S aureus strains were associated with more severe local disease and a greater systemic inflammatory response compared with osteomyelitis caused by pvl- S aureus.
Bocchini
Claire E
CE
Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA.
Hulten
Kristina G
KG
Mason
Edward O
EO
Gonzalez
Blanca E
BE
Hammerman
Wendy A
WA
Kaplan
Sheldon L
SL
D000208:Acute Disease; D018829:Adhesins, Bacterial / Q000235:genetics; D001427:Bacterial Toxins; D002648:Child; D002675:Child, Preschool; D017714:Community-Acquired Infections; D005098:Exotoxins / Q000235:genetics*; D005260:Female; D006801:Humans; D007223:Infant; D007956:Leukocidins / Q000235:genetics*; D008297:Male; D016106:Methicillin Resistance; D010019:Osteomyelitis / Q000175:diagnosis / Q000382:microbiology / Q000473:pathology*; D013203:Staphylococcal Infections / Q000175:diagnosis / Q000382:microbiology / Q000473:pathology*; D013211:Staphylococcus aureus / Q000187:drug effects / Q000235:genetics*
D018829:Adhesins, Bacterial; D001427:Bacterial Toxins; D005098:Exotoxins; D007956:Leukocidins; C078284:Panton-Valentine leukocidin; C078635:fibronectin-binding proteins, bacterial