title: Genotypic and phenotypic characterization of Staphylococcus aureus strains isolated in subjects with atopic dermatitis. Higher prevalence of exfoliative B toxin production in lesional strains and correlation between the markers of disease intensity and colonization density.
abstract: Staphylococcus aureus strains generally colonize eczematous lesions of subjects with atopic dermatitis much more frequently than in the skin of normal individuals. The aim of this study was to provide a detailed genotypic and phenotypic analysis of S. aureus strains colonizing four different sites (lesional and non-lesional skin areas, nasal and pharyngeal mucosas) of 49 patients with atopic dermatitis. The 88 isolates were analyzed in duplicate by pulsed field gel electrophoresis and in their exfoliative toxin A or B production by latex test. The patients were characterized by age, sex, severity scoring of atopic dermatitis and serum eosinophil cationic protein. Fourteen (28.6%) of the patients were completely negative for S. aureus while 35 (71.4%) were positive in at least one site. The severity scores and eosinophil cationic protein levels were significantly correlated variables (P<0.001), linked to the colonization intensity (P ranging between 0.05 and <0.001 depending on the site) and to the number of colonized sites (P at least <0.01). The genotypic patterns, widely heterogeneous, showed no restriction to peculiar patterns. Only eight strains produced exfoliative toxin B which was significantly restricted to the lesional isolates (P=0.012).
authors.affiliation: Laboratory of Clinical Pathology and Microbiology, Istituto San Gallicano, Rome, Italy. ecapoluongo@rm.unicatt.it
authors.forename: E
authors.initials: E
authors.lastname: Capoluongo
authors.forename: A
authors.initials: A
authors.lastname: Giglio A
authors.forename: M M
authors.initials: MM
authors.lastname: Lavieri
authors.forename: I
authors.initials: I
authors.lastname: Lesnoni-La Parola
authors.forename: C
authors.initials: C
authors.lastname: Ferraro
authors.forename: A
authors.initials: A
authors.lastname: Cristaudo
authors.forename: M
authors.initials: M
authors.lastname: Belardi
authors.forename: F
authors.initials: F
authors.lastname: Leonetti
authors.forename: A
authors.initials: A
authors.lastname: Mastroianni
authors.forename: A
authors.initials: A
authors.lastname: Cambieri
authors.forename: P
authors.initials: P
authors.lastname: Amerio
authors.forename: F
authors.initials: F
authors.lastname: Ameglio
mesh_terms: D000293:Adolescent; D000328:Adult; D001798:Blood Proteins / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D015169:Colony Count, Microbial; D003876:Dermatitis, Atopic / Q000097:blood / Q000382:microbiology*; D016521:Electrophoresis, Gel, Pulsed-Field; D047091:Eosinophil Granule Proteins; D005083:Exfoliatins / Q000096:biosynthesis; D005260:Female; D005838:Genotype; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D012260:Ribonucleases; D013211:Staphylococcus aureus / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity*
chemical_list: D001798:Blood Proteins; D047091:Eosinophil Granule Proteins; D005083:Exfoliatins; D012260:Ribonucleases