A novel virulence-associated protein, vapE, in Streptococcus suis serotype 2

Ji,Xue; Sun,Yang; Liu,Jun; Zhu,Lingwei; Guo,Xuejun; Lang,Xulong; Feng,Shuzhang

doi:10.3892/mmr.2016.4818

A novel virulence-associated protein, vapE, in Streptococcus suis serotype 2

Authors:
- Xue Ji
- Yang Sun
- Jun Liu
- Lingwei Zhu
- Xuejun Guo
- Xulong Lang
- Shuzhang Feng
View Affiliations

Affiliations: Molecular Bacteriology Department, Institute of Military Veterinary Science, Academy of Military Medical Sciences, Changchun, Jilin 130122, P.R. China
Published online on: January 28, 2016 https://doi.org/10.3892/mmr.2016.4818
Pages: 2871-2877

Metrics: Total Views: 0 (Spandidos Publications: | PMC Statistics: )

Metrics: Total PDF Downloads: 0 (Spandidos Publications: | PMC Statistics: )

Cited By (CrossRef): 0 citations Loading Articles...

Abstract

Streptococcus suis serotype 2 (SS2) is an important pathogen that affects pigs. However, neither its virulence nor its pathogenesis of infection has yet to be fully elucidated. The present study identifies a novel virulence‑associated protein E gene (vapE) of SS2. To investigate the importance of vapE in SS2 infection, a vapE knock‑out mutant based on SS2 wild‑type strain ZY458 was designated 458ΔvapE. 458ΔvapE was generated through homologous recombination, using a combined plasmid with a vapE knock‑out fragment and a pSET4s suicide vector. Additionally, the 458ΔvapE strain was transformed by a pAT18 shuttle plasmid containing the vapE gene. A functionally complemented strain for the vapE gene [termed 458ΔvapE (pvapE)] was constructed. Animal experiments demonstrated that mice infected with ZY458 and 458ΔvapE (pvapE) exhibited severe clinical symptoms, including depression, apathy, fever, anorexia, emaciation, swollen eyes and neural disorders, and died within two days of infection. All mice infected with ZY458, and 85% of mice infected with 458ΔvapE (pvapE), died within 2 days of infection. In contrast, mice inoculated with 458ΔvapE exhibited only mild clinical symptoms in the first 2 days following infection, and recovered within a week. A bacterial colonization assay demonstrated the ability of the 458ΔvapE mutant SS2 strain to colonize the heart, liver, spleen, lung and kidney of infected mice. PCR analysis of the vapE gene revealed that functional vapE was detected in virulent strains, but not in avirulent and carrier strains of S. suis SS2. These findings indicate that vapE is important for the pathogenesis of SS2.

View Figures

View References

1	Wertheim HF, Nghia HDT, Taylor W and Schultsz C: Streptococcus suis: an emerging human pathogen. Clin Infect Dis. 48:617–625. 2009. View Article : Google Scholar : PubMed/NCBI
2	Yu H, Jing H, Chen Z, Zheng H, Zhu X, Wang H, Wang S, Liu L, Zu R, Luo L, et al Streptococcus suis study groups: Human Streptococcus suis outbreak, Sichuan, China. Emerg Infect Dis. 12:914–920. 2006. View Article : Google Scholar : PubMed/NCBI
3	Gottschalk M and Segura M: The pathogenesis of the meningitis caused by Streptococcus suis: the unresolved questions. Vet Microbiol. 76:259–272. 2000. View Article : Google Scholar : PubMed/NCBI
4	Fittipaldi N, Segura M, Grenier D and Gottschalk M: Virulence factors involved in the pathogenesis of the infection caused by the swine pathogen and zoonotic agent Streptococcus suis. Future Microbiol. 7:259–279. 2012. View Article : Google Scholar : PubMed/NCBI
5	de Greeff A, Buys H, Verhaar R, Dijkstra J, van Alphen L and Smith HE: Contribution of fibronectin-binding protein to pathogenesis of Streptococcus suis serotype 2. Infect Immun. 70:1319–1325. 2002. View Article : Google Scholar : PubMed/NCBI
6	Baums CG, Kaim U, Fulde M, Ramachandran G, Goethe R and Valentin-Weigand P: Identification of a novel virulence determinant with serum opacification activity in Streptococcus suis. Infect Immun. 74:6154–6162. 2006. View Article : Google Scholar : PubMed/NCBI
7	Fittipaldi N, Sekizaki T, Takamatsu D, de la Cruz Domínguez-Punaro M, Harel J, Bui NK, Vollmer W and Gottschalk M: Significant contribution of the pgdA gene to the virulence of Streptococcus suis. Mol Microbiol. 70:1120–1135. 2008. View Article : Google Scholar : PubMed/NCBI
8	Si Y, Yuan F, Chang H, Liu X, Li H, Cai K, Xu Z, Huang Q, Bei W and Chen H: Contribution of glutamine synthetase to the virulence of Streptococcus suis serotype 2. Vet Microbiol. 139:80–88. 2009. View Article : Google Scholar : PubMed/NCBI
9	Ge J, Feng Y, Ji H, Zhang H, Zheng F, Wang C, Yin Z, Pan X and Tang J: Inactivation of dipeptidyl peptidase IV attenuates the virulence of Streptococcus suis serotype 2 that causes streptococcal toxic shock syndrome. Curr Microbiol. 59:248–255. 2009. View Article : Google Scholar : PubMed/NCBI
10	Zhang XH, He KW, Duan ZT, Zhou JM, Yu ZY, Ni YX and Lu CP: Identification and characterization of inosine 5-monophosphate dehydrogenase in Streptococcus suis type 2. Microb Pathog. 47:267–273. 2009. View Article : Google Scholar : PubMed/NCBI
11	Wu T, Zhao Z, Zhang L, Ma H, Lu K, Ren W, Liu Z, Chang H, Bei W, Qiu Y and Chen H: Trigger factor of Streptococcus suis is involved in stress tolerance and virulence. Microb Pathog. 51:69–76. 2011. View Article : Google Scholar
12	Li P, Liu J, Zhu L, Qi C, Bei W, Cai X, Sun Y and Feng S: VirA: A virulence-related gene of Streptococcus suis serotype 2. Microb Pathog. 49:305–310. 2010. View Article : Google Scholar : PubMed/NCBI
13	Zheng F, Ji H, Cao M, Wang C, Feng Y, Li M, Pan X, Wang J, Qin Y, Hu F and Tang J: Contribution of the Rgg transcription regulator to metabolism and virulence of Streptococcus suis serotype 2. Infect Immun. 79:1319–1328. 2011. View Article : Google Scholar :
14	Bonifait L and Grenier D: The SspA subtilisin-like protease of Streptococcus suis triggers a pro-inflammatory response in macrophages through a non-proteolytic mechanism. BMC Microbiol. 11:472011. View Article : Google Scholar : PubMed/NCBI
15	Willenborg J, Fulde M, de Greeff A, Rohde M, Smith HE, Valentin-Weigand P and Goethe R: Role of glucose and CcpA in capsule expression and virulence of Streptococcus suis. Microbiology. 157:1823–1833. 2011. View Article : Google Scholar : PubMed/NCBI
16	Tang Y, Zhang X, Wu W, Lu Z and Fang W: Inactivation of the sodA gene of Streptococcus suis type 2 encoding superoxide dismutase leads to reduced virulence to mice. Vet Microbiol. 158:360–366. 2012. View Article : Google Scholar : PubMed/NCBI
17	Chen C, Tang J, Dong W, Wang C, Feng Y, Wang J, Zheng F, Pan X, Liu D, Li M, et al: A glimpse of streptococcal toxic shock syndrome from comparative genomics of S. suis 2 Chinese isolates. PLoS One. 2:e3152007. View Article : Google Scholar : PubMed/NCBI
18	Li M, Wang C, Feng Y, Pan X, Cheng G, Wang J, Ge J, Zheng F, Cao M, Dong Y, et al: SalK/SalR, a two-component signal transduction system, is essential for full virulence of highly invasive Streptococcus suis serotype 2. PLoS One. 3:e20802008. View Article : Google Scholar : PubMed/NCBI
19	Qi C, Liu J, Zhu LW, Wang WD, Meng FQ and Feng SZ: Genetic difference between Streptococcus suis serotype 2 virulent strain and avirulent strain by suppression subtractive hybridization. Chin J Vet Sci. 588–593. 2009.In Chinese.
20	Sambrook J and Russell DW: Molecular Cloning: A Laboratory Manual. 3rd edition. Cold Spring Harbor Laboratory Press; New York: 2001
21	Takamatsu D, Osaki M and Sekizaki T: Construction and characterization of Streptococcus suis-Escherichia coli shuttle cloning vectors. Plasmid. 45:101–113. 2001. View Article : Google Scholar : PubMed/NCBI
22	Takamatsu D, Osaki M and Sekizaki T: Thermosensitive suicide vectors for gene replacement in Streptococcus suis. Plasmid. 46:140–148. 2001. View Article : Google Scholar : PubMed/NCBI
23	No Authors Listed. CIOMS International guiding principles for biomedical research involving animals. Altern Lab Anim. 12:ii1985.PubMed/NCBI
24	Wang G, Lo LF and Maier RJ: The RecRO pathway of DNA recombinational repair in Helicobacter pylori and its role in bacterial survival in the host. DNA Repair (Amst). 10:373–379. 2011. View Article : Google Scholar
25	Gottschalk M, Segura M and Xu J: Streptococcus suis infections in humans: The Chinese experience and the situation in North America. Anim Health Res Rev. 8:29–45. 2007. View Article : Google Scholar : PubMed/NCBI
26	Chou KC and Shen HB: Cell-PLoc: A package of web servers for predicting subcellular localization of proteins in various organisms. Nature Protoc. 3:153–162. 2008. View Article : Google Scholar
27	Wei W, Ding GH, Wang XQ, Sun JC, Tu K, Hao P, Wang C, Cao ZW, Shi TL and Li YX: Comparative genome analysis of Streptococcus suis. Chin Sci Bull. 51:808–818. 2006. View Article : Google Scholar
28	Juhas M, van der Meer JR, Gaillard M, Harding RM, Hood DW and Crook DW: Genomic islands: Tools of bacterial horizontal gene transfer and evolution. FEMS Microbiol Rev. 33:376–393. 2009. View Article : Google Scholar : PubMed/NCBI
29	Trieu-Cuot P, Carlier C, Poyart-Salmeron C and Courvalin P: Shuttle vectors containing a multiple cloning site and a lacZ α gene for conjugal transfer of DNA from Escherichia coli to gram-positive bacteria. Gene. 102:99–104. 1991. View Article : Google Scholar : PubMed/NCBI
30	Quessy S, Dubreuil JD, Caya M and Higgins R: Discrimination of virulent and avirulent Streptococcus suis capsular type 2 isolates from different geographical origins. Infect Immun. 63:1975–1979. 1995.PubMed/NCBI
31	Vela AI, Goyache J, Tarradas C, Luque I, Mateos A, Moreno MA, Borge C, Perea JA, Domínguez L and Fernández-Garayzábal JF: Analysis of genetic diversity of Streptococcus suis clinical isolates from pigs in Spain by pulsed-field gel electrophoresis. J Clin Microbiol. 41:2498–2502. 2003. View Article : Google Scholar : PubMed/NCBI