AUTHOR=Ndhlovu Gillian O. N. , Javkar Kiran G. , Matuvhunye Takudzwa , Ngondoh Froodia , Jamrozy Dorota , Bentley Stephen , Shittu Adebayo O. , Dube Felix S. 

TITLE=Investigating genomic diversity of Staphylococcus aureus associated with pediatric atopic dermatitis in South Africa

JOURNAL=Frontiers in Microbiology

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2024.1422902

DOI=10.3389/fmicb.2024.1422902

ISSN=1664-302X

ABSTRACT=<sec id="sec1"><title>Importance</title><p><italic>Staphylococcus aureus</italic> frequently colonizes the skin and nose of patients with atopic dermatitis (AD), a disease associated with skin barrier dysfunction and chronic cutaneous inflammation. Published genomic studies on AD-associated <italic>S. aureus</italic> in pediatric populations in sub-Saharan Africa are limited.</p></sec><sec id="sec2"><title>Objectives</title><p>To investigate the phenotypic and genomic diversity of <italic>S. aureus</italic> in children with and without AD during early childhood.</p></sec><sec id="sec3"><title>Data, setting and participants</title><p>A cross-sectional study of 220 children (aged 9–38 months) with AD (cases) and without AD (controls) from Cape Town and Umtata, South Africa.</p></sec><sec id="sec4"><title>Main outcomes and measures</title><p><italic>S. aureus</italic> phenotypic and genomic diversity were investigated using whole-genome sequencing, antibiotic susceptibility testing and biofilm microtiter assay.</p></sec><sec id="sec5"><title>Results</title><p>Of the 124 <italic>S. aureus</italic> isolates recovered from 220 children, 96 isolates (79 cases and 17 controls) with high-quality sequences were analyzed. Isolates from cases showed greater phenotypic resistance to gentamicin (10%), rifampicin (4%), chloramphenicol (4%), and exhibited multidrug resistance (9%) than in controls. Furthermore, the isolates from cases formed stronger biofilms than those from controls (76% vs. 35%, <italic>p</italic> = 0.001), but showed no dominance of any virulence factor gene or mobile genetic elements. There was no significant difference in the distribution of immune evasion cluster types between cases and controls. However, IEC type G was identified only among cases.</p></sec><sec id="sec6"><title>Conclusion and relevance</title><p>AD-associated <italic>S. aureus</italic> has phenotypic and genetic features that are important for successful pathogenic colonization and survival. Further studies are needed to assess the pathological implications of colonization of various <italic>S. aureus</italic> lineages <italic>in vivo</italic> to elucidate their pathological contribution to AD pathogenesis and pathophysiology.</p></sec>