Comparative study of staphylococci from the skin of atopic dermatitis patients and from healthy subjects

Background Bacterial infections occur frequently on the skin of atopic derm atitis (AD) patients. The objectives of this study were to evaluate the mic robiology of the skin of AD patients for staphylococci, the frequency and d ensity of each species, and their susceptibility to antimicrobial drugs. Methods To study the staphylococci present on the skin of 21 AD outpatients and of 12 healthy subjects (HS), cutaneous organisms were obtained using t he contact-plate method. Results Staphylococcus aureus was isolated in 85.7% of AD patients (mild ty pe, 77.8%; moderate type, 87.8%; and severe type, 100%) and in 25% of HS, w hile Staphylococcus epidermidis was isolated in 83.3% of HS and in 38.1% of AD patients. Among the coagulase-negative staphylococci (CNS) identified, S. epidermidis was the common type and several other CNS were detected in b oth AD patients and HS, As the eruption grade of dermatitic skin became mor e severe, the average density of S, aureus increased (severe, 2.68 +/- 0.86 ; moderate, 2.49 +/- 0.48; mild, 2.28 +/- 0.44), A reversed tendency was se en in S. epidermidis(severe, 1.80; moderate, 1.90; mild, 2.10). Among nine antimicrobial drugs tested against S. aureus, S. epidermidis, and some othe r types of CNS isolates, vancomycin (VCM) and minocycline (MINO) were the m ost active, gentamycin (GM) was the less active, and ampicillin (ABPC) was the least active. Conclusions The skin of AD patients was more frequently colonized with S. a ureus than that of normal controls. As the severity of the AD lesions incre ased, the numbers of S. aureus isolated increased. The skin of HS was more colonized with S, epidermidis. Other species of CNS were isolated from seve ral cases of AD patients and HS. In addition, S. aureus, S. epidermidis, an d the other CNS showed poor susceptibility to some of the tested antimicrob ial drugs.