The widespread use of topical antimicrobials enriches for resistance in Staphylococcus aureus isolated from patients with atopic dermatitis
Research output: Contribution to journal › Article › peer-review
- University of Dundee
- Trinity College Dublin
- Temple Street Children's University Hospital
- University Medical Center
- University of St Andrews
- University of Glasgow
- Wellcome Sanger Institute
BACKGROUND: Carriage rates of Staphylococcus aureus on affected skin in atopic dermatitis (AD) are approximately 70%. Increasing disease severity during flares and overall disease severity correlate with increased burden of S. aureus. Treatment in AD therefore often targets S. aureus with topical and systemic antimicrobials.
OBJECTIVES: To determine whether antimicrobial sensitivities and genetic determinants of resistance differed in S. aureus isolates from the skin of children with AD and healthy child nasal carriers.
METHODS: In this case-control study, we compared S. aureus isolates from children with AD (n = 50) attending a hospital dermatology department against nasal carriage isolates from children without skin disease (n = 49) attending a hospital emergency department for noninfective conditions. Using whole genome sequencing we generated a phylogenetic framework for the isolates based on variation in the core genome, then compared antimicrobial resistance phenotypes and genotypes between disease groups.
RESULTS: Staphylococcus aureus from cases and controls had on average similar numbers of phenotypic resistances per isolate. Case isolates differed in their resistance patterns, with fusidic acid resistance (FusR ) being significantly more frequent in AD (P = 0·009). The genetic basis of FusR also differentiated the populations, with chromosomal mutations in fusA predominating in AD (P = 0·049). Analysis revealed that FusR evolved multiple times and via multiple mechanism in the population. Carriage of plasmid-derived qac genes, which have been associated with reduced susceptibility to antiseptics, was eight times more frequent in AD (P = 0·016).
CONCLUSIONS: The results suggest that strong selective pressure drives the emergence and maintenance of specific resistances in AD.
|Number of pages||8|
|Journal||British Journal of Dermatology|
|Publication status||Published - Oct 2018|
- Administration, Cutaneous, Anti-Infective Agents, Local/administration & dosage, Carrier State/diagnosis, Case-Control Studies, Child, Child, Preschool, Dermatitis, Atopic/diagnosis, Drug Resistance, Bacterial/drug effects, Female, Healthy Volunteers, Humans, Infant, Infant, Newborn, Male, Microbial Sensitivity Tests, Mutation, Nasal Mucosa/microbiology, Peptide Elongation Factor G/genetics, Severity of Illness Index, Skin/microbiology, Staphylococcal Skin Infections/diagnosis, Staphylococcus aureus/isolation & purification