The involvement of MsmK in pathogenesis of the Streptococcus suis serotype 2
Mei-Fang Tan1,2, Wan-Quan Liu1, Chun-Yan Zhang1
1State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.
Abstract:
Streptococcus suis serotype 2 (SS2) is an important swine and human pathogen that causes global economic and public health problems. Virulent S. suis strains successfully maintain high bacterial concentrations in host blood and rapidly adapt to challenging environments within hosts. Successful survival in hosts is a major factor influencing the pathogenesis of SS2. We have previously identified that SS2 colonization in mouse brain is possibly affected by the ATPase, MsmK of carbohydrate ATP-binding cassette (ABC) transporters because of carbohydrate utilization. In this study, the chain length of the msmK deletion mutant was longer than that of the wild type, and the former was significantly more susceptible than the latter when theses strains were exposed to mouse blood both in vivo and in vitro. The hemolytic activity of the mutant strain was decreased. Although the adhesion of the mutant to HEp-2 cell lines was enhanced, the deletion of msmK impaired the abilities of SS2 to resist phagocytosis and survive severe stress conditions. MsmK contributed to the survival and adaptation of SS2 in host bloodstream. Therefore, MsmK was identified as a multifunctional component that not only contributed to carbohydrate utilization but also participated in SS2 pathogenesis.
Insights
Streptococcus suis serotype 2 (SS2) MsmK protein is crucial for bacterial survival in host blood. Deleting msmK in SS2 impairs resistance to phagocytosis and stress, impacting pathogenesis.
Area of Science:
- Microbiology
- Bacteriology
- Pathogenesis
Background:
- Streptococcus suis serotype 2 (SS2) is a significant swine and human pathogen.
- Virulent SS2 strains exhibit robust survival and adaptation within host environments.
- Host bloodstream survival is a key factor in SS2 pathogenesis.
Purpose of the Study:
- To investigate the role of the ATPase MsmK in SS2 survival and pathogenesis.
- To determine MsmK's contribution to carbohydrate utilization and adaptation within the host.
Main Methods:
- Construction and characterization of an msmK deletion mutant of SS2.
- In vitro and in vivo assays evaluating bacterial survival in mouse blood.
- Assessment of hemolytic activity, HEp-2 cell adhesion, phagocytosis resistance, and stress tolerance.
Main Results:
- The msmK deletion mutant showed increased susceptibility in mouse blood (in vitro and in vivo).
- Hemolytic activity was reduced in the mutant strain.
- While HEp-2 cell adhesion increased, the mutant exhibited impaired resistance to phagocytosis and severe stress.
Conclusions:
- MsmK is essential for SS2 survival and adaptation in the host bloodstream.
- MsmK plays a multifunctional role, contributing to both carbohydrate utilization and SS2 pathogenesis.
