Panton-Valentine leukocidin-positive methicillin-resistant Staphylococcus aureus infections in children with cancer.
BACKGROUND
New strains of methicillin-resistant Staphylococcus aureus (MRSA) which frequently carry the Panton-Valentine leukocidin (PVL) genes have been recognized to cause invasive infections in otherwise healthy children and adults. However, the epidemiology of PVL-positive MRSA infections has not been described in children or adults with cancer.


METHODS
The epidemiology of MRSA infections in patients with cancer was retrospectively studied from 2000 to 2007. Molecular typing was performed by polymerase chain reaction (PCR) for the detection of the PVL genes. Staphylococcus cassette chromosome (SCC) mec and spa typing was performed on all PVL-positive isolates.


RESULTS
A total of 88 MRSA isolates from clinically distinct infectious episodes were collected from 88 patients with cancer during the 8-year study period. Infections were predominant in the skin and soft tissues (SSTI; P = 0.0003). PVL-positive isolates, bearing the type IV SCCmec element, encoding the gene for methicillin resistance, increased significantly during this period (P = 0.043) and comprised 35 of 88 (40%) MRSA isolates. Of these 35 isolates, 32 belonged to spa type 8 and were USA300 genotype. Patients infected with PVL-positive strains did not have more SSTI (P = 0.166) or bacteremia (P = 0.510) as compared to patients with PVL-negative strains. A greater percentage of PVL-positive isolates were susceptible to ciprofloxacin (P = 0.006).


CONCLUSIONS
PVL-positive MRSA infections are not associated with a higher morbidity as compared to PVL-negative MRSA infections in children with cancer.
Srinivasan
Ashok
A
Department of Oncology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA. ashok.srinivasan@stjude.org
Seifried
Steven
S
Zhu
Liang
L
Srivastava
Deo K
DK
Flynn
Patricia M
PM
Shenep
Jerry L
JL
Bankowski
Matthew J
MJ
Hayden
Randall T
RT
D000293:Adolescent; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D016470:Bacteremia / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology; D001426:Bacterial Proteins / Q000235:genetics; D001427:Bacterial Toxins / Q000032:analysis / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D002939:Ciprofloxacin / Q000627:therapeutic use; D005098:Exotoxins / Q000032:analysis / Q000235:genetics*; D005260:Female; D006801:Humans; D007223:Infant; D007956:Leukocidins / Q000032:analysis / Q000235:genetics*; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D009369:Neoplasms / Q000150:complications*; D046915:Penicillin-Binding Proteins; D012189:Retrospective Studies; D018461:Soft Tissue Infections / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D013205:Staphylococcal Protein A / Q000235:genetics
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D005098:Exotoxins; D007956:Leukocidins; C078284:Panton-Valentine leukocidin; D046915:Penicillin-Binding Proteins; D013205:Staphylococcal Protein A; C487789:mecA protein, Staphylococcus aureus; D002939:Ciprofloxacin