Invasive streptococcal infection can lead to the generation of cross-strain opsonic antibodies

• DOI: 10.1101/2022.06.27.497877
• Publication Date: 2022-07-01T12:40:11Z
• Authors: Therese de Neergaard; Anna Bläckberg; Hanna Ivarsson; Sofia Thomasson; Vibha Kumra Ahnlide; Sounak Chowdhury; Hamed Khakzad; Johan Malmström; Magnus Rasmussen; Pontus Nordenfelt
• Keywords: Streptococcus Pyogenes; Antibody titer

Abstract Introduction The human pathogen Streptococcus pyogenes causes substantial morbidity and mortality. It is unclear if antibodies developed after infections with this are opsonic they strain-specific or more broadly protective. Here, we quantified the antibody response following invasive S. infection. Materials Methods Four patients bacteremia between 2018-2020 at Skåne University Hospital in Lund, Sweden, were prospectively enrolled. Acute convalescent sera obtained, isolates genome-sequenced ( emm 118, 85, two 1). Quantitative binding phagocytosis assays used to evaluate isolate-dependent function Results Antibody increased modestly against infecting isolate across types compared acute for all patients. For patients, serum both types. increase was only one patient, had no improvement. No correlation clinical outcomes observed. Conclusion Invasive result a differential capacity, non-functional These findings question dogma that an infection should lead strong type-specific rather than modest but reactive response, as seen these Furthermore, our results indicate titers might not be indicative of highlight importance evaluating infections.