Laura Hughes (UMC Groningen)

Summary of presentation:
Introduction:
Staphylococcus aureus sequence type 152 is a lineage primarily associated with sub-Saharan Africa and the Caribbean. It frequently carries genes encoding Panton–Valentine leukocidin (PVL), epidermal cell differentiation inhibitor B (edinB) and the exfoliative toxin E variant etE2, first described in 2022. These virulence factors have been implicated in rapid tissue destruction and fulminant disease. In Europe, this lineage has mainly been described as methicillin-resistant and community associated, while severe infections caused by methicillin-susceptible strains remain rare. We observed several severe infections caused by methicillin-susceptible sequence type 152 in the north of the Netherlands.

Methods:
We performed a retrospective analysis of all patients from whom Staphylococcus aureus sequence type 152 has been isolated in the region. Clinical information was extracted from medical records. Whole-genome sequencing was conducted for strain characterisation, including identification of virulence genes.

Results:
Twelve patients were identified, with isolates first detected in 2021 and continuing through 2025. Six patients had severe community-onset infections caused by methicillin-susceptible sequence type 152, including necrotising pneumonia, necrotising fasciitis and necrotic cellulitis. In four pneumonia cases, disease onset followed respiratory viral infection. Clinical courses were characterised by respiratory failure, circulatory collapse, multiorgan dysfunction and the need for intensive care support, invasive ventilation, extracorporeal therapy or surgical intervention. Two patients died. Whole-genome sequencing showed that 10 isolates carried PVL, edinB and etE2, while two lacked edinB and etE2, likely due to a deletion within the genomic island that normally contains these genes. Six patients carried methicillin-resistant sequence type 152 identified through screening; none of which developed disease and no epidemiological link was observed.

Conclusion:
Be alert for severe infections caused by methicillin-susceptible Staphylococcus aureus sequence type 152 carrying multiple virulence factors. These findings support increased awareness and targeted genomic characterisation of invasive S. aureus, especially during periods of high circulation of respiratory viruses.