The collagen-binding protein of Streptococcus mutans is involved in haemorrhagic stroke
- Kazuhiko Nakano,
- Kazuya Hokamura,
- Naho Taniguchi,
- Koichiro Wada,
- Chiho Kudo,
- Ryota Nomura,
- Ayuchi Kojima,
- Shuhei Naka,
- Yoshinori Muranaka,
- Min Thura,
- Atsushi Nakajima,
- Katsuhiko Masuda,
- Ichiro Nakagawa,
- Pietro Speziale,
- Nobumitsu Shimada,
- Atsuo Amano,
- Yoshinori Kamisaki,
- Tokutaro Tanaka,
- Kazuo Umemura
- & Takashi Ooshima
Abstract
Although several risk factors for
stroke
have been identified, one-third remain unexplained. Here we show that
infection
with Streptococcus
mutansexpressing collagen-binding protein (CBP) is a potential risk
factor
for haemorrhagic stroke. Infection with serotype k S. mutans, but not a
standard
strain, aggravates cerebral haemorrhage in mice. Serotype k S. mutansaccumulates in
the
damaged, but not the contralateral hemisphere, indicating an interaction of
bacteria with injured blood vessels. The most important factor for
high-virulence is expression of CBP, which is a common property of most
serotype k strains. The detection frequency of
CBP-expressing S.
mutans in haemorrhagic
stroke
patients is significantly higher than in control subjects. Strains isolated
from
haemorrhagic stroke patients aggravate haemorrhage in a mouse model,
indicating
that they are haemorrhagic stroke-associated. Administration of recombinant
CBP
causes aggravation of haemorrhage. Our data suggest that CBP of S.
mutans is directly
involved in
haemorrhagic
stroke.
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