title: Staphylococcus aureus abscesses: methicillin-resistance or Panton-Valentine leukocidin presence?
abstract: BACKGROUND
  Panton-Valentine leukocidin (PVL) is a toxin associated with community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) worldwide and also occurs in community-associated methicillin-susceptible S aureus (CA-MSSA) strains. The aims of the study were to determine the prevalence of PVL in community-onset S aureus skin and soft-tissue infections (SSTIs) and to analyse the influence of methicillin resistance and PVL presence on the clinical characteristics of these infections.
  
  
  METHODS
  We prospectively enrolled all children with S aureus community-onset SSTIs attending the emergency department of a tertiary hospital between 2007 and 2009. Results A total of 142 S aureus SSTIs were identified, 46 (32%) were PVL positive. The proportion of subjects in each group was: 89 (63%) PVL-MSSA, 33 (23%) PVL+MSSA, 13 (9%) PVL+MRSA and 7 (5%) PVL-MRSA. PVL+infections were more frequently abscesses (63% vs 39%, p<0.01), and more often required incision and drainage (p<0.01) and hospital admission (46% vs 26%, p=0.02). MRSA infections were also more frequently associated with abscesses but in a multivariable analysis only PVL remained independently related (OR 2.33; 95% CI 1.10 to 4.90).
  
  
  CONCLUSIONS
  Our study found a high prevalence of PVL presence in community-onset S aureus SSTIs in children in Spain. This toxin is associated with more abscess formation, regardless of methicillin resistance.
authors.affiliation: Department of Paediatrics, Hospital Universitario12 de Octubre de Madrid, Madrid, Spain. mbarrioslopez@yahoo.es
authors.forename: Marta
authors.initials: M
authors.lastname: Barrios López
authors.forename: Carmen
authors.initials: C
authors.lastname: Gómez González
authors.forename: M Ángeles
authors.initials: MÁ
authors.lastname: Orellana
authors.forename: Fernando
authors.initials: F
authors.lastname: Chaves
authors.forename: Pablo
authors.initials: P
authors.lastname: Rojo
mesh_terms: D000038:Abscess / Q000453:epidemiology* / Q000382:microbiology; D000293:Adolescent; D001427:Bacterial Toxins / Q000032:analysis*; D002648:Child; D002675:Child, Preschool; D005098:Exotoxins / Q000032:analysis*; D005260:Female; D006801:Humans; D007223:Infant; D007956:Leukocidins / Q000032:analysis*; D008297:Male; D016106:Methicillin Resistance; D015995:Prevalence; D011446:Prospective Studies; D018461:Soft Tissue Infections / Q000453:epidemiology*; D013203:Staphylococcal Infections / Q000453:epidemiology*; D013207:Staphylococcal Skin Infections / Q000453:epidemiology; D013211:Staphylococcus aureus
chemical_list: D001427:Bacterial Toxins; D005098:Exotoxins; D007956:Leukocidins; C078284:Panton-Valentine leukocidin
keywords: Infectious Diseases; Microbiology; Paediatrics