Resistance to clinically important antibiotics and reduced susceptibility to disinfectants in the pandemic ST398 methicillin-susceptible Staphylococcus aureus from Austria
Year: 2026
Type: article
Abstract: Introduction Staphylococcus aureus is a frequent coloniser and pathogen of humans and animals. The prevalence of human-associated methicillin-susceptible Staphylococcus aureus (MSSA) belonging to the pandemic sequence type (ST) 398 has been increasing globally; however, there are regional variations, with a high prevalence in France and a low prevalence in neighbouring Germany. Transmission within the community is thought to play an important role in its spread, as well as the presence of the scn gene, a marker of human adaptation. Methods Environmental swabs were plated on Columbia sheep blood agar. A hemolytic isolate was identified as S. aureus by MALDI–ToF, and was tested for antimicrobial susceptibility to antibiotics using the Vitek 2 system and to disinfectants via broth microdilution. It was whole-genome sequenced using Illumina and bioinformatically analysed with respect to antimicrobial resistance genes, virulence-associated genes, ST, spa type, plasmids, prophages, and phylogenetic relationships with 273 other MSSA ST398 strains. Results An MSSA strain belonging to ST398, of a yet-undescribed spa type (succession of repeat codes: 08-83-34-25), was isolated from a household in Vienna, Austria. The isolate was phenotypically classified as resistant to clindamycin and erythromycin, and as susceptible to levofloxacin under increased exposure, according to EUCAST guidelines. In addition, it had reduced susceptibility to the disinfectants benzalkonium chloride and chlorhexidine. Whole-genome sequencing revealed the presence of antimicrobial resistance and virulence-associated genes, including the ermT gene, located on a plasmid, and the scn gene, found on the StauST398 prophage. The isolate clustered most closely with human- and animal-derived isolates from France, almost all of which contained the phage-associated scn gene. Discussion These preliminary results, based on a single isolate, demonstrate that an antibiotic-resistant S. aureus with potentially mobile antimicrobial resistance and virulence-associated genes belonging to MSSA ST398 is present in Austria. Further expanded surveillance efforts are needed to accurately assess its prevalence in the community. The reduced susceptibility to disinfectants in this strain is concerning, as it may negatively affect mitigation efforts. Its relatedness to other European isolates from humans and animals calls for a One Health approach to surveillance.
Source: Frontiers in Microbiology
Authors: Adrienn Gréta Tóth, Olga Makarova
Language: English
Subfield: Infectious Diseases
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $3,801
OpenAlex ID: W7155095080