Fatty Acid Supplementation Reverses the Small Colony Variant Phenotype in Triclosan-Adapted Staphylococcus aureus: Genetic, Proteomic and Phenotypic Analyses

• Published in: Scientific reports 2018-03, Vol.8 (1), p.3876-9, Article 3876
• Main Authors: Bazaid, Abdulrahman S., Forbes, Sarah, Humphreys, Gavin J., Ledder, Ruth G., O’Cualain, Ronan, McBain, Andrew J.
• Format: Article
• Language: English
• Subjects: 14/63; 45/23; 631/326/1320; 631/326/22/1434; 82/81; Biocides; Colonies; Dietary supplements; Fatty acids; Genetic analysis; Genomes; Growth rate; Humanities and Social Sciences; multidisciplinary; Mutation; Pathogenicity; Pathogens; Phenotypes; Science; Science (multidisciplinary); Staphylococcus aureus; Triclosan; Virulence factors
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-018-21925-6

Staphylococcus aureus can develop a small colony variant (SCV) phenotype in response to sub-lethal exposure to the biocide triclosan. In the current study, whole genome sequencing was performed and changes in virulence were investigated in five Staphylococcus aureus strains following repeated exposure to triclosan. Following exposure, 4/5 formed SCV and exhibited point mutations in the triclosan target gene fabI with 2/4 SCVs showing mutations in both fabI and fabD . The SCV phenotype was in all cases immediately reversed by nutritional supplementation with fatty acids or by repeated growth in the absence of triclosan, although fabI mutations persisted in 3/4 reverted SCVs. Virulence, determined using keratinocyte invasion and Galleria mellonella pathogenicity assays was significantly (p