A serine/threonine phosphatase 1 of Streptococcus suis type 2 is an important virulence factor.
10.4142/jvs.2017.18.4.439
- Author:
Lihua FANG
1
;
Jingjing ZHOU
;
Pengcheng FAN
;
Yunkai YANG
;
Hongxia SHEN
;
Weihuan FANG
Author Information
1. Zhejiang University Institute of Preventive Veterinary Medicine and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Hangzhou 310058, China. whfang@zju.edu.cn
- Publication Type:Original Article
- Keywords:
Streptococcus suis type 2;
serine/threonine protein phosphatase;
virulence
- MeSH:
Animals;
Bacterial Load;
Humans;
Lethal Dose 50;
Macrophages;
Meningitis;
Mice;
Oxidative Stress;
Parents;
Phosphoprotein Phosphatases;
Reactive Oxygen Species;
Streptococcus suis*;
Streptococcus*;
Swine;
Virulence*
- From:Journal of Veterinary Science
2017;18(4):439-447
- CountryRepublic of Korea
- Language:English
-
Abstract:
Streptococcus suis is regarded as one of the major pathogens of pigs, and Streptococcus suis type 2 (SS2) is considered a zoonotic bacterium based on its ability to cause meningitis and streptococcal toxic shock-like syndrome in humans. Many bacterial species contain genes encoding serine/threonine protein phosphatases (STPs) responsible for dephosphorylation of their substrates in a single reaction step. This study investigated the role of stp1 in the pathogenesis of SS2. An isogenic stp1 mutant (Δstp1) was constructed from SS2 strain ZJ081101. The Δstp1 mutant exhibited a significant increase in adhesion to HEp-2 and bEnd.3 cells as well as increased survival in RAW264.7 cells, as compared to the parent strain. Increased survival in macrophage cells might be related to resistance to reactive oxygen species since the Δstp1 mutant was more resistant than its parent strain to paraquat-induced oxidative stress. However, compared to parent strain virulence, deletion of stp1 significantly attenuated virulence of SS2 in mice, as shown by the nearly double lethal dose 50 value and the lower bacterial load in organs and blood in the murine model. We conclude that Stp1 has an essential role in SS2 virulence.
