Streptococcus suis enolase functions as a protective antigen displayed on the bacterial cell surface.

Abstract

BACKGROUND:

Streptococcus suis serotype 2 (SS2) has evolved into a highly infectious entity, posing a great threat to public health. Screening for and identification of protective antigens plays an important role in developing therapies against SS2 infections.

METHODS:

Multiple strategies were used to investigate a new surface protein that has the potential to be a protective antigen. These strategies included molecular cloning, biochemical and biophysical analyses, enzymatic assay, immunological approaches (eg, immunoelectron microscopy), and experimental infections of animals.

RESULTS:

We identified an enolase gene from SS2 and systematically characterized its protein product, enolase. Biophysical data indicated that S. suis enolase is an octameric protein. Enzymatic assays verified its ability to catalyze the dehydration of 2-phospho-D-glycerate to phosphoenolpyruvate. In consideration of the strong antigenicity of enolase, an efficient enolase-based method was established for monitoring SS2 infections. Combined evidence strongly indicated that SS2 enolase can localize on the bacterial cell surface and facilitate bacterial adherence. Additionally, we found that enolase can confer complete protection against SS2 infection to mice, which suggests that enolase has potential as a vaccine candidate.

CONCLUSIONS:

We conclude that S. suis enolase functions as a protective antigen displayed on the bacterial cell surface and that it can be used to develop new strategies to combat SS2 infections.

• Authors: Youjun Feng, Xiuzhen Pan, Wen Sun, Changjun Wang, Huimin Zhang, Xianfu Li, Ying Ma, Zhuqing Shao, Junchao Ge, Feng Zheng, George F Gao, Jiaqi Tang
• Journal: The Journal of infectious diseases (J Infect Dis) Vol. 200 Issue 10 Pg. 1583-92 (Nov 15 2009) ISSN: 1537-6613 [Electronic] United States
• PMID: 19848587 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Adhesins, Bacterial
• Antigens, Bacterial
• Virulence Factors
• Phosphopyruvate Hydratase

Topics

• Adhesins, Bacterial (chemistry, genetics)
• Animals
• Antigens, Bacterial (chemistry, genetics)
• Communicable Diseases, Emerging (microbiology)
• Humans
• Mice
• Phosphopyruvate Hydratase (chemistry, genetics, immunology)
• Streptococcal Infections (enzymology)
• Streptococcus suis (enzymology)
• Sus scrofa
• Swine Diseases (microbiology)
• Vaccination
• Virulence Factors
• Zoonoses (microbiology)