Transcriptomic analysis of Streptococcus agalactiae periprosthetic joint
infection
Abstract
Although Streptococcus agalactiae periprosthetic joint infection (PJI)
is not as prevalent as staphylococcal PJI, invasive S. agalactiae
infection has recently increased in incidence. Here, RNA-Seq was used to
perform transcriptomic analysis of S. agalactiae PJI using fluid derived
from sonication of explanted arthroplasties of subjects with S.
agalactiae PJI, with results compared to those of S. agalactiae strain
NEM316 grown in vitro. 227 genes with outlier expression were found (164
up-regulated and 63 down-regulated) between PJI sonicate fluid and in
vitro conditions. Functional enrichment analysis showed genes involved
in mobilome and inorganic ion transport and metabolism to be most
enriched. Genes involved in nickel, copper, and zinc transport, were
upregulated. Among known virulence factors, cyl operon genes, encoding
beta-hemolysin/cytolysin, were consistently highly expressed in PJI
versus in vitro. The data presented provide insight into S. agalactiae
PJI pathogenesis and may be a useful resource for the identification of
novel PJI therapeutics or vaccines against invasive S. agalactiae
infections.