Humoral immune consequences of Staphylococcus aureus ST239-associated bacteremia

• Published in: European journal of clinical microbiology & infectious diseases 2018-02, Vol.37 (2), p.255-263
• Main Authors: Ghasemzadeh-Moghaddam, H., van Wamel, WJB, van Belkum, A., Hamat, R. A., Tavakol, M., Neela, V. K.
• Format: Article
• Language: English
• Subjects: Antibodies; Antigens; Bacteremia; Biomedical and Life Sciences; Biomedicine; Drug resistance; Immune response; Immune response (humoral); Immune system; Immunoglobulin G; Internal Medicine; Medical Microbiology; Methicillin; Multilocus sequence typing; Original Article; Patients; Staphylococcus aureus; Staphylococcus infections
• ISSN: 0934-9723; 1435-4373
• DOI: 10.1007/s10096-017-3124-3

The humoral immune responses against 46 different staphylococcal antigens in 27 bacteremia patients infected by clonally related methicillin-resistant Staphylococcus aureus (MRSA) strains of a single sequence type (ST) 239 were investigated. A group of non-infected patients ( n  = 31) hospitalized for different reasons served as controls. All strains were confirmed as ST 239 by S. aureus and mecA- specific PCR, spa , and multi-locus sequence typing (MLST). In each bacteremia patient, a unique pattern of S. aureus antigen-specific immune responses after infection was observed. Antibody levels among bacteremia patients were significantly higher than controls for HlgB ( P  = 0.001), LukD ( P  = 0.009), LukF ( P  = 0.0001), SEA ( P  = 0.0001), SEB ( P  = 0.011), SEC ( P  = 0.010), SEQ ( P  = 0.049), IsaA ( P  = 0.043), IsdA ( P  = 0.038), IsdH ( P  = 0.01), SdrD ( P  = 0.001), SdrE ( P  = 0.046), EsxA ( P  = 0.0001), and SA0104 ( P  = 0.0001). On the other hand, the antibody levels were significantly higher among controls for SSL3 ( P  = 0.009), SSL9 ( P  = 0.002), and SSL10 ( P  = 0.007) when the IgG level on the day of infection was compared with that measured on the day of admission. Diversity was observed in the immune response against the antigens. However, a set of antigens (IsaA, IsdA, IsdH, SdrD, and HlgB) triggered a similar type of immune response in different individuals. We suggest that these antigens could be considered when developing a multi-component (passive) vaccine. SEA and/or its specific antibodies seem to play a critical role during ST239 MRSA bacteremia and SEA-targeted therapy may be a strategy to be considered.