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Liedel C, Rieckmann K, Baums CG. A critical review on experimental Streptococcus suis infection in pigs with a focus on clinical monitoring and refinement strategies. BMC Vet Res 2023; 19:188. [PMID: 37798634 PMCID: PMC10552360 DOI: 10.1186/s12917-023-03735-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 09/14/2023] [Indexed: 10/07/2023] Open
Abstract
Streptococcus suis (S. suis) is a major pig pathogen worldwide with zoonotic potential. Though different research groups have contributed to a better understanding of the pathogenesis of S. suis infections in recent years, there are still numerous neglected research topics requiring animal infection trials. Of note, animal experiments are crucial to develop a cross-protective vaccine which is highly needed in the field. Due to the severe clinical signs associated with S. suis pathologies such as meningitis and arthritis, implementation of refinement is very important to reduce pain and distress of experimentally infected pigs. This review highlights the great diversity of clinical signs and courses of disease after experimental S. suis pig infections. We review clinical read out parameters and refinement strategies in experimental S. suis pig infections published between 2000 and 2021. Currently, substantial differences exist in describing clinical monitoring and humane endpoints. Most of the reviewed studies set the body temperature threshold of fever as high as 40.5°C. Monitoring intervals vary mainly between daily, twice a day and three times a day. Only a few studies apply scoring systems. Published scoring systems are inconsistent in their inclusion of parameters such as body temperature, feeding behavior, and respiratory signs. Locomotion and central nervous system signs are more common clinical scoring parameters in different studies by various research groups. As the heterogenicity in clinical monitoring limits the comparability between studies we hope to initiate a discussion with this review leading to an agreement on clinical read out parameters and monitoring intervals among S. suis research groups.
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Affiliation(s)
- Carolin Liedel
- Institute of Bacteriology and Mycology, Centre for Infectious Diseases, Faculty of Veterinary Medicine, Leipzig University, An den Tierkliniken 29, Leipzig, 04103, Germany
| | - Karoline Rieckmann
- Institute of Bacteriology and Mycology, Centre for Infectious Diseases, Faculty of Veterinary Medicine, Leipzig University, An den Tierkliniken 29, Leipzig, 04103, Germany
| | - Christoph G Baums
- Institute of Bacteriology and Mycology, Centre for Infectious Diseases, Faculty of Veterinary Medicine, Leipzig University, An den Tierkliniken 29, Leipzig, 04103, Germany.
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2
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Lou F, Huang H, Li Y, Yang S, Shi Y. Investigation of the inhibitory effect and mechanism of epigallocatechin-3-gallate against Streptococcus suis sortase A. J Appl Microbiol 2023; 134:lxad191. [PMID: 37634082 DOI: 10.1093/jambio/lxad191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 08/11/2023] [Accepted: 08/25/2023] [Indexed: 08/28/2023]
Abstract
AIMS Streptococcus suis seriously harms people and animals, and importantly, causes great economic losses in the pig industry. Similar to most Gram-positive pathogenic bacteria, sortase A (SrtA) of S. suis can mediate the anchoring of a variety of virulence factors that contain specific sorting sequences to the surface of the bacterial cell wall envelope and participate in pathogenicity. The purpose of this study is to clarify the molecular mechanism of epigallocatechin-3-gallate (EGCG) inhibiting S. suis SrtA and provide more evidence for the development of novel anti-S. suis infections drugs. METHODS AND RESULTS Through the SrtA substrate cleavage experiment, we found that the main component of green tea, EGCG, can effectively inhibit the enzyme activity of S. suis SrtA. Further, molecular docking and molecular dynamics simulation were used to clarify the molecular mechanism of its inhibitory effect, demonstrating that EGCG mainly interacts with amino acids at 113 and 115 to exert its inhibitory function. It was previously found that EGCG can inhibit the growth of S. suis and reduce the activity of suilysin and inhibit its expression. Our research reveals a new function of EGCG in S. suis infection. CONCLUSIONS Our research proves that EGCG can effectively inhibit the transpeptidase activity of SrtA. We also clarify the accompanying molecular mechanism, providing more sufficient evidence for the use of EGCG as a potential lead compound against S. suis infection.
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Affiliation(s)
- Fei Lou
- College of Veterinary Medicine, Henan University of Animal Husbandry and Economy, Zhengzhou, China
| | - Hui Huang
- College of Veterinary Medicine, Henan University of Animal Husbandry and Economy, Zhengzhou, China
| | - Yaping Li
- School of Basic Medical Sciences, Beihua University, Jilin, China
| | - Shuo Yang
- School of Basic Medical Sciences, Beihua University, Jilin, China
| | - Yangqian Shi
- School of Basic Medical Sciences, Beihua University, Jilin, China
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3
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Fan J, Zhao L, Hu Q, Li S, Li H, Zhang Q, Zou G, Zhang L, Li L, Huang Q, Zhou R. Screening for Virulence-Related Genes via a Transposon Mutant Library of Streptococcus suis Serotype 2 Using a Galleria mellonella Larvae Infection Model. Microorganisms 2022; 10:microorganisms10050868. [PMID: 35630313 PMCID: PMC9143085 DOI: 10.3390/microorganisms10050868] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 04/13/2022] [Accepted: 04/20/2022] [Indexed: 01/27/2023] Open
Abstract
Streptococcus suis (S. suis) is a zoonotic bacterial pathogen causing lethal infections in pigs and humans. Identification of virulence-related genes (VRGs) is of great importance in understanding the pathobiology of a bacterial pathogen. To identify novel VRGs, a transposon (Tn) mutant library of S. suis strain SC19 was constructed in this study. The insertion sites of approximately 1700 mutants were identified by Tn-seq, which involved 417 different genes. A total of 32 attenuated strains were identified from the library by using a Galleria mellonella larvae infection model, and 30 novel VRGs were discovered, including transcription regulators, transporters, hypothetical proteins, etc. An isogenic deletion mutant of hxtR gene (ΔhxtR) and its complementary strain (CΔhxtR) were constructed, and their virulence was compared with the wild-type strain in G. mellonella larvae and mice, which showed that disruption of hxtR significantly attenuated the virulence. Moreover, the ΔhxtR strain displayed a reduced survival ability in whole blood, increased sensitivity to phagocytosis, increased chain length, and growth defect. Taken together, this study performed a high throughput screening for VRGs of S. suis using a G. mellonella larvae model and further characterized a novel critical virulence factor.
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Affiliation(s)
- Jingyan Fan
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; (J.F.); (L.Z.); (Q.H.); (S.L.); (H.L.); (Q.Z.); (G.Z.); (L.Z.); (L.L.)
| | - Lelin Zhao
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; (J.F.); (L.Z.); (Q.H.); (S.L.); (H.L.); (Q.Z.); (G.Z.); (L.Z.); (L.L.)
| | - Qiao Hu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; (J.F.); (L.Z.); (Q.H.); (S.L.); (H.L.); (Q.Z.); (G.Z.); (L.Z.); (L.L.)
| | - Siqi Li
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; (J.F.); (L.Z.); (Q.H.); (S.L.); (H.L.); (Q.Z.); (G.Z.); (L.Z.); (L.L.)
| | - Haotian Li
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; (J.F.); (L.Z.); (Q.H.); (S.L.); (H.L.); (Q.Z.); (G.Z.); (L.Z.); (L.L.)
| | - Qianqian Zhang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; (J.F.); (L.Z.); (Q.H.); (S.L.); (H.L.); (Q.Z.); (G.Z.); (L.Z.); (L.L.)
| | - Geng Zou
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; (J.F.); (L.Z.); (Q.H.); (S.L.); (H.L.); (Q.Z.); (G.Z.); (L.Z.); (L.L.)
| | - Liangsheng Zhang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; (J.F.); (L.Z.); (Q.H.); (S.L.); (H.L.); (Q.Z.); (G.Z.); (L.Z.); (L.L.)
| | - Lu Li
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; (J.F.); (L.Z.); (Q.H.); (S.L.); (H.L.); (Q.Z.); (G.Z.); (L.Z.); (L.L.)
- International Research Center for Animal Disease (Ministry of Science & Technology of China), Wuhan 430070, China
- Cooperative Innovation Center of Sustainable Pig Production, Wuhan 430070, China
| | - Qi Huang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; (J.F.); (L.Z.); (Q.H.); (S.L.); (H.L.); (Q.Z.); (G.Z.); (L.Z.); (L.L.)
- International Research Center for Animal Disease (Ministry of Science & Technology of China), Wuhan 430070, China
- Cooperative Innovation Center of Sustainable Pig Production, Wuhan 430070, China
- Correspondence: (Q.H.); (R.Z.)
| | - Rui Zhou
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; (J.F.); (L.Z.); (Q.H.); (S.L.); (H.L.); (Q.Z.); (G.Z.); (L.Z.); (L.L.)
- International Research Center for Animal Disease (Ministry of Science & Technology of China), Wuhan 430070, China
- Cooperative Innovation Center of Sustainable Pig Production, Wuhan 430070, China
- The HZAU-HVSEN Research Institute, Wuhan 430042, China
- Correspondence: (Q.H.); (R.Z.)
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4
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Evaluation of immune effect of Streptococcus suis biofilm-associated protein PDH. Vet Microbiol 2021; 263:109270. [PMID: 34749282 DOI: 10.1016/j.vetmic.2021.109270] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 10/29/2021] [Indexed: 11/23/2022]
Abstract
As a zoonotic pathogen, Streptococcus suis(S. suis) takes pigs as the main host and is mainly colonizes in the upper respiratory tract and tonsil of pigs, causing septicemia, endocarditis and meningitis in pigs. Pyruvate dehydrogenase (PDH) is an enzyme that catalyzes the conversion of pyruvate to acetyl-CoA. As an immunogenic membrane-associated protein in S. suis, it has been found to be closely related to the formation of biofilm. In this study, the recombinant PDH (rPDH) of S. suis ZY05719 (serotype 2) was expressed and purified in E. coli by His affinity chromatography. Western blotting analysis showed that there was a strong specific reaction between PDH protein and PDH antiserum. Mice were immunized with recombinant PDH and inactivated bacteria, and the relative survival rates were 70 % and 60 %, respectively. In addition, mice immunized with PDH caused high levels of antibodies and high expression of immune-related genes in the spleen, which significantly protected the liver, brain and spleen from pathological damage. In addition, PDH antiserum could significantly inhibit the growth of S. suis and the formation of S. suis biofilm in vitro. These results further suggest that PDH is a promising candidate for S. suis biofilm-related subunit vaccine.
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5
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Susmitha A, Bajaj H, Madhavan Nampoothiri K. The divergent roles of sortase in the biology of Gram-positive bacteria. ACTA ACUST UNITED AC 2021; 7:100055. [PMID: 34195501 PMCID: PMC8225981 DOI: 10.1016/j.tcsw.2021.100055] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 06/11/2021] [Accepted: 06/11/2021] [Indexed: 12/16/2022]
Abstract
The bacterial cell wall contains numerous surface-exposed proteins, which are covalently anchored and assembled by a sortase family of transpeptidase enzymes. The sortase are cysteine transpeptidases that catalyzes the covalent attachment of surface protein to the cell wall peptidoglycan. Among the reported six classes of sortases, each distinct class of sortase plays a unique biological role in anchoring a variety of surface proteins to the peptidoglycan of both pathogenic and non-pathogenic Gram-positive bacteria. Sortases not only exhibit virulence and pathogenesis properties to host cells, but also possess a significant role in gut retention and immunomodulation in probiotic microbes. The two main distinct functions are to attach proteins directly to the cell wall or assemble pili on the microbial surface. This review provides a compendium of the distribution of different classes of sortases present in both pathogenic and non-pathogenic Gram-positive bacteria and also the noteworthy role played by them in bacterial cell wall assembly which enables each microbe to effectively interact with its environment.
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Affiliation(s)
- Aliyath Susmitha
- Microbial Processes and Technology Division, CSIR - National Institute for Interdisciplinary Science and Technology (NIIST), Trivandrum 695019, Kerala, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Harsha Bajaj
- Microbial Processes and Technology Division, CSIR - National Institute for Interdisciplinary Science and Technology (NIIST), Trivandrum 695019, Kerala, India
| | - Kesavan Madhavan Nampoothiri
- Microbial Processes and Technology Division, CSIR - National Institute for Interdisciplinary Science and Technology (NIIST), Trivandrum 695019, Kerala, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
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6
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Zhang H, Zhou T, Su L, Wang H, Zhang B, Su Y. Effects of srtA variation on phagocytosis resistance and immune response of Streptococcus equi. INFECTION GENETICS AND EVOLUTION 2021; 89:104732. [PMID: 33503504 DOI: 10.1016/j.meegid.2021.104732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 12/17/2020] [Accepted: 01/21/2021] [Indexed: 11/26/2022]
Abstract
Strangles, which is caused by Streptococcus equi subspecies equi (S. equi), is one of the most prevalent equine infectious diseases with worldwide distribution and leads to serious economic loss in the horse industry. Sortase A (srtA) is a transpeptidase that anchors multiple virulence-associated surface proteins to the cell surface of S. equi. srtA plays a major role in S. equi infection and colonization of the host cell. In this study, we aimed to investigate the effects of srtA mutation on the phagocytic activity and immunogenicity of S. equi. The point-mutated recombinant sortases, including srtA-HT1112 (I88V), srtA-5012 (R147G), and srtA-ZZM17 (control), were expressed, purified, and used to immunize the mouse models. Phagocytic activity was assessed using equine polymorphonuclear cells, whereas opsonophagocytic function and adherence inhibition were measured using the antiserum of these mutants. Mouse serum antibody, bacterial load, and weight gain were also measured. The srtA-HT1112 (I88V) mutant showed significantly enhanced antiphagocytic capability, and its antiserum exhibited increased adherence inhibition activity. In addition, the srtA-HT1112 (I88V) mutant presented the highest lung bacterial load and lowest protection rate (50%) after the challenge with S. equi ZZM17. The srtA-5012 (R147G) mutant exhibited a high IgG2a level and protection rate (62.5%-75%) and the lowest lung bacterial load. These results indicate that the I88V mutation is associated with a high antiphagocytic activity, whereas R147G mutation is associated with the decreased lung bacterial load. Our findings may be useful for the evaluation and development of vaccines.
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Affiliation(s)
- Huan Zhang
- Department of Microbiology and Immunology, College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, Xinjiang, China
| | - Tingting Zhou
- Department of Microbiology and Immunology, College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, Xinjiang, China
| | - Lining Su
- Xinjiang Academy of Animal Science, Urumqi, Xinjiang, China
| | - Hao Wang
- Department of Microbiology and Immunology, College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, Xinjiang, China
| | - Baojiang Zhang
- Department of Microbiology and Immunology, College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, Xinjiang, China
| | - Yan Su
- Department of Microbiology and Immunology, College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, Xinjiang, China.
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7
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Tram G, Jennings MP, Blackall PJ, Atack JM. Streptococcus suis pathogenesis-A diverse array of virulence factors for a zoonotic lifestyle. Adv Microb Physiol 2021; 78:217-257. [PMID: 34147186 DOI: 10.1016/bs.ampbs.2020.12.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Streptococcus suis is a major cause of respiratory tract and invasive infections in pigs and is responsible for a substantial disease burden in the pig industry. S. suis is also a significant cause of bacterial meningitis in humans, particularly in South East Asia. S. suis expresses a wide array of virulence factors, and although many are described as being required for disease, no single factor has been demonstrated to be absolutely required. The lack of uniform distribution of known virulence factors among individual strains and lack of evidence that any particular virulence factor is essential for disease makes the development of vaccines and treatments challenging. Here we review the current understanding of S. suis virulence factors and their role in the pathogenesis of this important zoonotic pathogen.
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Affiliation(s)
- Greg Tram
- Institute for Glycomics, Griffith University, Gold Coast, QLD, Australia
| | - Michael P Jennings
- Institute for Glycomics, Griffith University, Gold Coast, QLD, Australia
| | - Patrick J Blackall
- Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St. Lucia, QLD, Australia
| | - John M Atack
- Institute for Glycomics, Griffith University, Gold Coast, QLD, Australia.
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8
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Ni H, Li M, Wang Q, Wang J, Liu X, Zheng F, Hu D, Yu X, Han Y, Zhang Q, Zhou T, Wang Y, Wang C, Gao J, Shao ZQ, Pan X. Inactivation of the htpsA gene affects capsule development and pathogenicity of Streptococcus suis. Virulence 2020; 11:927-940. [PMID: 32815473 PMCID: PMC7567435 DOI: 10.1080/21505594.2020.1792080] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Streptococcus suis serotype 2 (S. suis 2) is an important swine pathogen and also an emerging zoonotic agent. HtpsA has been reported as an immunogenic cell surface protein on the bacterium. In the present study, we constructed an isogenic mutant strain of htpsA, namely ΔhtpsA, to study its role in the development and virulence of S. suis 2. Our results showed that the mutant strain lost its typical encapsulated structure with decreased concentrations of sialic acid. Furthermore, the survival rate in whole blood, the anti-phagocytosis by RAW264.7 murine macrophage, and the adherence ability to HEp-2 cells were all significantly affected in the ΔhtpsA. In addition, the deletion of htpsA sharply attenuated the virulence of S. suis 2 in an infection model of mouse. RNA-seq analysis revealed that 126 genes were differentially expressed between the ΔhtpsA and the wild-type strains, including 28 upregulated and 98 downregulated genes. Among the downregulated genes, many were involved in carbohydrate metabolism and synthesis of virulence-associated factors. Taken together, htpsA was demonstrated to play a role in the morphological development and pathogenesis of the highly virulent S. suis 2 05ZYH33 strain.
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Affiliation(s)
- Hua Ni
- Department of Microbiology, Hua Dong Research Institute for Medicine and Biotechnics , Nanjing, China.,Key Laboratory of Biological Resources and Ecology of Pamirs Plateau in Xinjiang Uygur Autonomous Region, College of Life and Geographic Sciences, Kashi University , Kashi, China
| | - Min Li
- Department of Microbiology, Hua Dong Research Institute for Medicine and Biotechnics , Nanjing, China.,Clinical Laboratory Department of Changzhi, People's Hospital , Changzhi, China
| | - Qiaoqiao Wang
- Department of Microbiology, Hua Dong Research Institute for Medicine and Biotechnics , Nanjing, China.,School of Life Sciences, Nanjing Normal University , Nanjing, China
| | - Jing Wang
- Department of Laboratory Medicine, The Affiliated Wuxi Maternity and Child Health Care Hospital of Nanjing Medical University , Wuxi, China
| | - Xumiao Liu
- Department of Microbiology, Hua Dong Research Institute for Medicine and Biotechnics , Nanjing, China.,School of Life Sciences, Nanjing Normal University , Nanjing, China
| | - Feng Zheng
- Department of Microbiology, Hua Dong Research Institute for Medicine and Biotechnics , Nanjing, China
| | - Dan Hu
- Department of Microbiology, Hua Dong Research Institute for Medicine and Biotechnics , Nanjing, China
| | - Xu Yu
- Department of Microbiology, Hua Dong Research Institute for Medicine and Biotechnics , Nanjing, China
| | - Yifang Han
- Department of Microbiology, Hua Dong Research Institute for Medicine and Biotechnics , Nanjing, China
| | - Qi Zhang
- Department of Microbiology, Hua Dong Research Institute for Medicine and Biotechnics , Nanjing, China
| | - Tingting Zhou
- Department of Microbiology, Hua Dong Research Institute for Medicine and Biotechnics , Nanjing, China
| | - Yiwen Wang
- Department of Microbiology, Hua Dong Research Institute for Medicine and Biotechnics , Nanjing, China
| | - Chunhui Wang
- Department of Microbiology, Hua Dong Research Institute for Medicine and Biotechnics , Nanjing, China
| | - Jimin Gao
- School of Laboratory Medicine and Life Science, Wenzhou Medical University , Wenzhou, China
| | - Zhu-Qing Shao
- Department of Microbiology, Hua Dong Research Institute for Medicine and Biotechnics , Nanjing, China.,State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University , Nanjing, China
| | - Xiuzhen Pan
- Department of Microbiology, Hua Dong Research Institute for Medicine and Biotechnics , Nanjing, China.,School of Life Sciences, Nanjing Normal University , Nanjing, China.,School of Laboratory Medicine and Life Science, Wenzhou Medical University , Wenzhou, China
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9
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Wang Y, Wang Y, Liu B, Wang S, Li J, Gong S, Sun L, Yi L. pdh modulate virulence through reducing stress tolerance and biofilm formation of Streptococcus suis serotype 2. Virulence 2020; 10:588-599. [PMID: 31232165 PMCID: PMC6592368 DOI: 10.1080/21505594.2019.1631661] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Streptococcus suis serotype 2 (S. suis 2) is a zoonotic pathogen. It causes meningitis, arthritis, pneumonia and sepsis in pigs, leading to extremely high mortality, which seriously affects public health and the development of the pig industry. Pyruvate dehydrogenase (PDH) is an important sugar metabolism enzyme that is widely present in microorganisms, mammals and higher plants. It catalyzes the irreversible oxidative decarboxylation of pyruvate to acetyl-CoA and reduces NAD+ to NADH. In this study, we found that the virulence of the S. suis ZY05719 sequence type 7 pdh deletion strain (Δpdh) was significantly lower than the wild-type strain (WT) in the mouse infection model. The distribution of viable bacteria in the blood and organs of mice infected with the Δpdh was significantly lower than those infected with WT. Bacterial survival rates were reduced in response to temperature stress, salt stress and oxidative stress. Additionally, compared to WT, the ability to adhere to and invade PK15 cells, biofilm formation and stress resistance of Δpdh were significantly reduced. Moreover, real-time PCR results showed that pdh deletion reduced the expression of multiple adhesion-related genes. However, there was no significant difference in the correlation biological analysis between the complemented strain (CΔpdh) and WT. Moreover, the survival rate of Δpdh in RAW264.7 macrophages was significantly lower than that of the WT strain. This study shows that PDH is involved in the pathogenesis of S. suis 2 and reduction in virulence of Δpdh may be related to the decreased ability to resist stress of the strain.
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Affiliation(s)
- Yang Wang
- a College of Animal Science and Technology , Henan University of Science and Technology , Luoyang , China.,b Key Laboratory of Molecular Pathogen and Immunology of Animal of Luoyang , Luoyang , China
| | - Yuxin Wang
- a College of Animal Science and Technology , Henan University of Science and Technology , Luoyang , China
| | - Baobao Liu
- a College of Animal Science and Technology , Henan University of Science and Technology , Luoyang , China
| | - Shaohui Wang
- c Shanghai Veterinary Research Institute , Chinese Academy of Agricultural Sciences , Shanghai , China
| | - Jinpeng Li
- a College of Animal Science and Technology , Henan University of Science and Technology , Luoyang , China
| | - Shenglong Gong
- a College of Animal Science and Technology , Henan University of Science and Technology , Luoyang , China
| | - Liyun Sun
- a College of Animal Science and Technology , Henan University of Science and Technology , Luoyang , China.,b Key Laboratory of Molecular Pathogen and Immunology of Animal of Luoyang , Luoyang , China
| | - Li Yi
- d College of Life Science , Luoyang Normal University , Luoyang , China
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10
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Xia X, Qin W, Zhu H, Wang X, Jiang J, Hu J. How Streptococcus suis serotype 2 attempts to avoid attack by host immune defenses. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 2019; 52:516-525. [PMID: 30954397 DOI: 10.1016/j.jmii.2019.03.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Revised: 02/20/2019] [Accepted: 03/07/2019] [Indexed: 01/08/2023]
Abstract
Streptococcus suis (S. suis) type 2 (SS2) is an important zoonotic pathogen that causes swine streptococcosis, a widespread infectious disease that occurs in pig production areas worldwide and causes serious economic losses in the pork industry. Hosts recognize pathogen-associated molecular patterns (PAMPs) through pattern recognition receptors (PRRs) to activate both innate and acquired immune responses. However, S. suis has evolved multiple mechanisms to escape host defenses. Pathogenic proteins, such as enolase, double-component regulatory systems, factor H-combining proteins and other pathogenic and virulence factors, contribute to immune escape by evading host phagocytosis, reactive oxygen species (ROS), complement-mediated immune destruction, etc. SS2 can prevent neutrophil extracellular trap (NET) formation to avoid being trapped by porcine neutrophils and disintegrate host immunoglobulins via IgA1 hydrolases and IgM proteases. Currently, the pathogenesis of arthritis and meningitis caused by SS2 infection remains unclear, and further studies are necessary to elucidate it. Understanding immune evasion mechanisms after SS2 infection is important for developing high-efficiency vaccines and targeted drugs.
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Affiliation(s)
- Xiaojing Xia
- College of Animal Science and Veterinary Medicine, Henan Institute of Science and Technology, Xinxiang, China; Postdoctoral Research Base, Henan Institute of Science and Technology, Xinxiang, China; Postdoctoral Research Station, Henan Agriculture University, Zhengzhou, China
| | - Wanhai Qin
- Amsterdam UMC, University of Amsterdam, Center for Experimental and Molecular Medicine, Amsterdam Infection & Immunity, Meibergdreef 9, 1105AZ Amsterdam, Netherlands
| | - Huili Zhu
- College of Animal Science and Veterinary Medicine, Henan Institute of Science and Technology, Xinxiang, China
| | - Xin Wang
- College of Agriculture and Forestry Science, Linyi University, Linyi, China
| | - Jinqing Jiang
- College of Animal Science and Veterinary Medicine, Henan Institute of Science and Technology, Xinxiang, China.
| | - Jianhe Hu
- College of Animal Science and Veterinary Medicine, Henan Institute of Science and Technology, Xinxiang, China; Postdoctoral Research Base, Henan Institute of Science and Technology, Xinxiang, China.
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11
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Faulds-Pain A, Shaw HA, Terra VS, Kellner S, Brockmeier SL, Wren BW. The Streptococcos suis sortases SrtB and SrtF are essential for disease in pigs. MICROBIOLOGY-SGM 2018; 165:163-173. [PMID: 30543506 DOI: 10.1099/mic.0.000752] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The porcine pathogen Streptococcus suis colonizes the upper respiratory tracts of pigs, potentially causing septicaemia, meningitis and death, thus placing a severe burden on the agricultural industry worldwide. It is also a zoonotic pathogen that is known to cause systemic infections and meningitis in humans. Understanding how S. suis colonizes and interacts with its hosts is relevant for future strategies of drug and vaccine development. As with other Gram-positive bacteria, S. suis utilizes enzymes known as sortases to attach specific proteins bearing cell wall sorting signals to its surface, where they can play a role in host-pathogen interactions. The surface proteins of bacteria are often important in adhesion to and invasion of host cells. In this study, markerless in-frame deletion mutants of the housekeeping sortase srtA and the two pilus-associated sortases, srtB and srtF, were generated and their importance in S. suis infections was investigated. We found that all three of these sortases are essential to disease in pigs, concluding that their cognate-sorted proteins may also be useful in protecting pigs against infection.
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Affiliation(s)
- Alexandra Faulds-Pain
- 1Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Helen Alexandra Shaw
- 1Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK.,‡Present address: National Institute for Biological Standards and Control (NIBSC), South Mimms, Potters Bar, EN6 3QG, UK
| | - Vanessa Sofia Terra
- 1Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Steven Kellner
- 2USDA, ARS, National Animal Disease Center, 1920 Dayton Avenue, Ames, Iowa 50010, USA
| | - Susan L Brockmeier
- 2USDA, ARS, National Animal Disease Center, 1920 Dayton Avenue, Ames, Iowa 50010, USA
| | - Brendan W Wren
- 1Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
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12
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Wang J, Song M, Pan J, Shen X, Liu W, Zhang X, Li H, Deng X. Quercetin impairs Streptococcus pneumoniae biofilm formation by inhibiting sortase A activity. J Cell Mol Med 2018; 22:6228-6237. [PMID: 30334338 PMCID: PMC6237587 DOI: 10.1111/jcmm.13910] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 08/20/2018] [Indexed: 02/03/2023] Open
Abstract
Biofilm formation mediated by sortase A (srtA) is important for bacterial colonisation and resistance to antibiotics. Thus, the inhibitor of SrtA may represent a promising agent for bacterial infection. The structure of Streptococcus pneumoniae D39 srtA has been characterised by crystallisation. Site‐directed mutagenesis was used for the determination of the key residues for the activity of S. pneumoniae D39 srtA. An effective srtA inhibitor, quercetin, and its mechanism was further identified using srtA activity inhibition assay and molecular modelling. In this study, the crystal structure of S. pneumoniae D39 srtA has been solved and shown to contain a unique domain B. Additionally, its transpeptidase activity was evaluated in vitro. Based on the structure, we identified Cys207 as the catalytic residue, with His141 and Arg215 serving as binding sites for the peptide substrate. We found that quercetin can specifically compete with the natural substrate, leading to a significant decrease in the catalytic activity of this enzyme. In cells co‐cultured with this small molecule inhibitor, NanA cannot anchor to the cell wall effectively, and biofilm formation and biomass decrease significantly. Interestingly, when we supplemented cultures with sialic acid, a crucial signal for pneumococcal coloniation and the invasion of the host in the co‐culture system, biofilm loss did not occur. This result indicates that quercetin inhibits biofilm formation by affecting sialic acid production. In conclusion, the inhibition of pneumococcal srtA by the small molecule quercetin offers a novel strategy for pneumococcal preventative therapy.
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Affiliation(s)
- Jianfeng Wang
- Department of Respiratory Medicine, The First Hospital of Jilin University, Changchun, China.,Key Laboratory of Zoonosis, Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Meng Song
- Department of Respiratory Medicine, The First Hospital of Jilin University, Changchun, China.,Key Laboratory of Zoonosis, Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Juan Pan
- Tianjin International Travel Healthcare Center, Tianjin, China
| | - Xue Shen
- Department of Respiratory Medicine, The First Hospital of Jilin University, Changchun, China.,Key Laboratory of Zoonosis, Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Wentao Liu
- Heilongjiang Veterinary Drug and Feed Super Vision Institute, Haerbin, China
| | - Xueke Zhang
- Heilongjiang Veterinary Drug and Feed Super Vision Institute, Haerbin, China
| | - Hongen Li
- Department of Respiratory Medicine, The First Hospital of Jilin University, Changchun, China.,Key Laboratory of Zoonosis, Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Xuming Deng
- Department of Respiratory Medicine, The First Hospital of Jilin University, Changchun, China.,Key Laboratory of Zoonosis, Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun, China
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13
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Chang P, Li W, Shi G, Li H, Yang X, Xia Z, Ren Y, Li Z, Chen H, Bei W. The VraSR regulatory system contributes to virulence in Streptococcus suis via resistance to innate immune defenses. Virulence 2018; 9:771-782. [PMID: 29471718 PMCID: PMC5955479 DOI: 10.1080/21505594.2018.1428519] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Streptococcus suis is a highly invasive pathogen that can cause sepsis and meningitis in pigs and humans. However, we have limited understanding of the mechanisms S. suis uses to evade innate immunity. To investigate the involvement of the two-component signal transduction system of S. suis in host immune defense, we examined the expression of 15 response regulators of S. suis following stimulation with polymorphonuclear leukocytes (PMNs). We found that several response regulators were significantly up-regulated including vraR. Thus, we constructed an isogenic deletion mutant of vraSR genes in S. suis and demonstrated VraSR promotes both bacterial survival in human blood and resistance to human PMN-mediated killing. The VraSR mutant was more susceptible to phagocytosis by human PMNs and had greater sensitivity to oxidant and lysozyme than wild-type S. suis. Furthermore, in vitro findings and in vivo evidence from a mouse infection model together strongly demonstrate that ΔvraSR had greatly attenuated virulence compared with wild-type S. suis. Collectively, our data reveal that VraSR is a critical regulatory system that contributes to the survival of S. suis and its ability to defend against host innate immunity.
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Affiliation(s)
- Peixi Chang
- a State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , China.,b Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center of Sustainable Pig Production , Huazhong Agricultural University , Wuhan , China
| | - Weitian Li
- a State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , China
| | - Guolin Shi
- a State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , China.,b Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center of Sustainable Pig Production , Huazhong Agricultural University , Wuhan , China
| | - Huan Li
- a State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , China.,b Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center of Sustainable Pig Production , Huazhong Agricultural University , Wuhan , China
| | - Xiaoqing Yang
- c Huazhong Agricultural University hospital , Huazhong Agricultural University , Wuhan , China
| | - Zechen Xia
- d College of Food Science and Technology , Huazhong Agricultural University , Wuhan , China
| | - Yuan Ren
- a State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , China
| | - Zhiwei Li
- d College of Food Science and Technology , Huazhong Agricultural University , Wuhan , China
| | - Huanchun Chen
- a State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , China.,b Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center of Sustainable Pig Production , Huazhong Agricultural University , Wuhan , China
| | - Weicheng Bei
- a State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , China.,b Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center of Sustainable Pig Production , Huazhong Agricultural University , Wuhan , China
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14
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Zhang Q, Huang J, Yu J, Xu Z, Liu L, Song Y, Sun X, Zhang A, Jin M. HP1330 Contributes to Streptococcus suis Virulence by Inducing Toll-Like Receptor 2- and ERK1/2-Dependent Pro-inflammatory Responses and Influencing In Vivo S. suis Loads. Front Immunol 2017; 8:869. [PMID: 28824616 PMCID: PMC5534446 DOI: 10.3389/fimmu.2017.00869] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 07/10/2017] [Indexed: 11/17/2022] Open
Abstract
Streptococcus suis 2 (SS2) has evolved into a highly invasive pathogen responsible for two large-scale outbreaks of streptococcal toxic shock-like syndrome (STSLS) in China. Excessive inflammation stimulated by SS2 is considered a hallmark of STSLS, even it also plays important roles in other clinical symptoms of SS2-related disease, including meningitis, septicemia, and sudden death. However, the mechanism of SS2-caused excessive inflammation remains poorly understood. Here, a novel pro-inflammatory protein was identified (HP1330), which could induce robust expression of pro-inflammatory cytokines (TNF-α, MCP-1, and IL-1β) in RAW264.7 macrophages. To evaluate the role of HP1330 in SS2 virulence, an hp1330-deletion mutant (Δhp1330) was constructed. In vitro, hp1330 disruption led to a decreased pro-inflammatory ability of SS2 in RAW 264.7 macrophages. In vivo, Δhp1330 showed reduced lethality, pro-inflammatory activity, and bacterial loads in mice. To further elucidate the mechanism of HP1330-induced pro-inflammatory cytokine production, antibody blocking and gene-deletion experiments with macrophages were performed. The results revealed that the pro-inflammatory activity of HP1330 depended on the recognition of toll-like receptor 2 (TLR2). Furthermore, a specific inhibitor of the extracellular signal-regulated kinase 1/2 (ERK1/2) pathways could significantly decrease HP1330-induced pro-inflammatory cytokine production, and western blot analysis showed that HP1330 could induce activation of the ERK1/2 pathway. Taken together, our findings demonstrate that HP1330 contributes to SS2 virulence by inducing TLR2- and ERK1/2-dependent pro-inflammatory cytokine production and influencing in vivo bacterial loads, implying that HP1330 may be associated with STSLS caused by SS2.
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Affiliation(s)
- Qiang Zhang
- National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
| | - Jingjing Huang
- National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
| | - Junping Yu
- National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
| | - Zhongmin Xu
- National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
| | - Liang Liu
- National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
| | - Yajing Song
- National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
| | - Xiaomei Sun
- National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
| | - Anding Zhang
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture, Wuhan, China
| | - Meilin Jin
- National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China.,College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture, Wuhan, China
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15
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Streptococcus suis sortase A is Ca2+ independent and is inhibited by acteoside, isoquercitrin and baicalin. PLoS One 2017; 12:e0173767. [PMID: 28319184 PMCID: PMC5358767 DOI: 10.1371/journal.pone.0173767] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 02/27/2017] [Indexed: 11/30/2022] Open
Abstract
Sortase A (SrtA) has long been recognized as an ideal drug target for therapeutic agents against Gram-positive pathogens. However, the SrtA of Streptococcus suis (Ss-SrtA), an important zoonotic agent, has not been studied. In this study, the enzymatic properties of Ss-SrtA were investigated, and inhibition of Ss-SrtA by natural products was evaluated. Ss-SrtA was expressed and purified. The purified recombinant Ss-SrtA had maximal activity at pH 6.0–7.5, 45°C, and showed a Km of 6.7 μM for the hydrolysis of substrate abz-LPATG-dnp. Different from Staphylococcus aureus SrtA (Sa-SrtA) which is stimulated by Ca2+, Ss-SrtA was observed to be Ca2+ independent. Structural analysis showed that salt bridges formed between K111 and D180 in Ss-SrtA replaced the function of Ca2+ in Sa-SrtA to stabilize the substrate-binding cleft. Site-directed mutagenesis identified H126, C192 and R200 as the key residues of Ss-SrtA active site. To discover potential inhibitors, the percent inhibition of sortase activity by natural products was measured. Among these selected natural products, acteoside, isoquercitrin and baicalin were discovered as novel SrtA inhibitors, with IC50 values of 36.3 ± 1.3 μM, 100.0 ± 1.3 μM and 85.4 ± 1.5 μM, respectively. The inhibitory effects of these three natural products were further confirmed on endogenous Sa-SrtA. Using a previously established S. aureus model with a fluorescent-labeled Sa-SrtA substrate, acteoside, isoquercitrin, and baicalin showed 86%, 28% and 45% inhibition on endogenous Sa-SrtA activity, respectively. Overall, these findings shed new light on enzymatic properties, Ca2+-independent catalytic mechanism and potential inhibitors of Ss-SrtA.
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16
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Critical Streptococcus suis Virulence Factors: Are They All Really Critical? Trends Microbiol 2017; 25:585-599. [PMID: 28274524 DOI: 10.1016/j.tim.2017.02.005] [Citation(s) in RCA: 175] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 01/30/2017] [Accepted: 02/09/2017] [Indexed: 01/15/2023]
Abstract
Streptococcus suis is an important swine pathogen that can be transmitted to humans by contact with diseased animals or contaminated raw pork products. This pathogen possesses a coat of capsular polysaccharide (CPS) that confers protection against the immune system. Yet, the CPS is not the only virulence factor enabling this bacterium to successfully colonize, invade, and disseminate in its host leading to severe systemic diseases such as meningitis and toxic shock-like syndrome. Indeed, recent research developments, cautiously inventoried in this review, have revealed over 100 'putative virulence factors or traits' (surface-associated or secreted components, regulatory genes or metabolic pathways), of which at least 37 have been claimed as being 'critical' for virulence. In this review we discuss the current contradictions and controversies raised by this explosion of virulence factors and the future directions that may be conceived to advance and enlighten research on S. suis pathogenesis.
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17
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Segura M, Calzas C, Grenier D, Gottschalk M. Initial steps of the pathogenesis of the infection caused by Streptococcus suis: fighting against nonspecific defenses. FEBS Lett 2016; 590:3772-3799. [PMID: 27539145 DOI: 10.1002/1873-3468.12364] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2016] [Revised: 08/11/2016] [Accepted: 08/16/2016] [Indexed: 12/16/2022]
Abstract
Interactions between a bacterial pathogen and its potentially susceptible host are initiated with the colonization step. During respiratory/oral infection, the pathogens must compete with the normal microflora, resist defense mechanisms of the local mucosal immunity, and finally reach, adhere, and breach the mucosal epithelial cell barrier in order to induce invasive disease. This is the case during infection by the swine and zoonotic pathogen Streptococcus suis, which is able to counteract mucosal barriers to induce severe meningitis and sepsis in swine and in humans. The initial steps of the pathogenesis of S. suis infection has been a neglected area of research, overshadowed by studies on the systemic and central nervous phases of the disease. In this Review article, we provide for the first time, an exclusive focus on S. suis colonization and the potential mechanisms involved in S. suis establishment at the mucosa, as well as the mechanisms regulating mucosal barrier breakdown. The role of mucosal immunity is also addressed. Finally, we demystify the extensive list of putative adhesins and virulence factors reported to be involved in the initial steps of pathogenesis by S. suis.
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Affiliation(s)
- Mariela Segura
- Laboratory of Immunology, Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, Quebec, Canada.,Swine and Poultry Infectious Diseases Research Centre (CRIPA), Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, QC, Canada
| | - Cynthia Calzas
- Laboratory of Immunology, Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, Quebec, Canada.,Swine and Poultry Infectious Diseases Research Centre (CRIPA), Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, QC, Canada.,Laboratory of Streptococcus suis, Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, Quebec, Canada
| | - Daniel Grenier
- Swine and Poultry Infectious Diseases Research Centre (CRIPA), Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, QC, Canada.,Groupe de Recherche en Écologie Buccale (GREB), Faculté de Médecine Dentaire, Université Laval, Quebec City, Quebec, Canada
| | - Marcelo Gottschalk
- Swine and Poultry Infectious Diseases Research Centre (CRIPA), Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, QC, Canada.,Laboratory of Streptococcus suis, Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, Quebec, Canada
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18
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Binding of Human Fibrinogen to MRP Enhances Streptococcus suis Survival in Host Blood in a αXβ2 Integrin-dependent Manner. Sci Rep 2016; 6:26966. [PMID: 27231021 PMCID: PMC4882601 DOI: 10.1038/srep26966] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 05/11/2016] [Indexed: 12/11/2022] Open
Abstract
The Gram-positive bacterium Streptococcus suis serotype 2 (S. suis 2), an important zoonotic pathogen, induces strong systemic infections in humans; sepsis and meningitis are the most common clinical manifestations and are often accompanied by bacteremia. However, the mechanisms of S. suis 2 survival in human blood are not well understood. In our previous study, we identified muramidase-released protein (MRP), a novel human fibrinogen (hFg)-binding protein (FBP) in S. suis 2 that is an important epidemic infection marker with an unknown mechanism in pathogenesis. The present study demonstrates that the N-terminus of MRP (a.a. 283–721) binds to both the Aα and Bβ chains of the D fragment of hFg. Strikingly, the hFg-MRP interaction improved the survival of S. suis 2 in human blood and led to the aggregation and exhaustion of polymorphonuclear neutrophils (PMNs) via an αXβ2 integrin-dependent mechanism. Other Fg-binding proteins, such as M1 (GAS) and FOG (GGS), also induced PMNs aggregation; however, the mechanisms of these FBP-hFg complexes in the evasion of PMN-mediated innate immunity remain unclear. MRP is conserved across highly virulent strains in Europe and Asia, and these data shed new light on the function of MRP in S. suis pathogenesis.
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Kebouchi M, Galia W, Genay M, Soligot C, Lecomte X, Awussi AA, Perrin C, Roux E, Dary-Mourot A, Le Roux Y. Implication of sortase-dependent proteins of Streptococcus thermophilus in adhesion to human intestinal epithelial cell lines and bile salt tolerance. Appl Microbiol Biotechnol 2016; 100:3667-79. [DOI: 10.1007/s00253-016-7322-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Revised: 01/10/2016] [Accepted: 01/13/2016] [Indexed: 01/06/2023]
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Raz A, Tanasescu AM, Zhao AM, Serrano A, Alston T, Sol A, Bachrach G, Fischetti VA. Streptococcus pyogenes Sortase Mutants Are Highly Susceptible to Killing by Host Factors Due to Aberrant Envelope Physiology. PLoS One 2015; 10:e0140784. [PMID: 26484774 PMCID: PMC4617865 DOI: 10.1371/journal.pone.0140784] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 09/30/2015] [Indexed: 12/31/2022] Open
Abstract
Cell wall anchored virulence factors are critical for infection and colonization of the host by Gram-positive bacteria. Such proteins have an N-terminal leader sequence and a C-terminal sorting signal, composed of an LPXTG motif, a hydrophobic stretch, and a few positively charged amino acids. The sorting signal halts translocation across the membrane, allowing sortase to cleave the LPXTG motif, leading to surface anchoring. Deletion of sortase prevents the anchoring of virulence factors to the wall; the effects on bacterial physiology however, have not been thoroughly characterized. Here we show that deletion of Streptococcus pyogenes sortase A leads to accumulation of sorting intermediates, particularly at the septum, altering cellular morphology and physiology, and compromising membrane integrity. Such cells are highly sensitive to cathelicidin, and are rapidly killed in blood and plasma. These phenomena are not a loss-of-function effect caused by the absence of anchored surface proteins, but specifically result from the accumulation of sorting intermediates. Reduction in the level of sorting intermediates leads to a return of the sortase mutant to normal morphology, while expression of M protein with an altered LPXTG motif in wild type cells leads to toxicity in the host environment, similar to that observed in the sortase mutant. These unanticipated effects suggest that inhibition of sortase by small-molecule inhibitors could similarly lead to the rapid elimination of pathogens from an infected host, making such inhibitors much better anti-bacterial agents than previously believed.
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Affiliation(s)
- Assaf Raz
- Bacterial Pathogenesis and Immunology, The Rockefeller University, 1230 York Avenue Box 172, New York, New York, 10065, United States of America
| | - Ana-Maria Tanasescu
- Bacterial Pathogenesis and Immunology, The Rockefeller University, 1230 York Avenue Box 172, New York, New York, 10065, United States of America
| | - Anna M. Zhao
- Bacterial Pathogenesis and Immunology, The Rockefeller University, 1230 York Avenue Box 172, New York, New York, 10065, United States of America
| | - Anna Serrano
- Bacterial Pathogenesis and Immunology, The Rockefeller University, 1230 York Avenue Box 172, New York, New York, 10065, United States of America
| | - Tricia Alston
- Bacterial Pathogenesis and Immunology, The Rockefeller University, 1230 York Avenue Box 172, New York, New York, 10065, United States of America
| | - Asaf Sol
- Institute of Dental Sciences, Hebrew University - Hadassah School of Dental Medicine, Jerusalem 91120, Israel
| | - Gilad Bachrach
- Institute of Dental Sciences, Hebrew University - Hadassah School of Dental Medicine, Jerusalem 91120, Israel
| | - Vincent A. Fischetti
- Bacterial Pathogenesis and Immunology, The Rockefeller University, 1230 York Avenue Box 172, New York, New York, 10065, United States of America
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21
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Hatrongjit R, Kerdsin A, Gottschalk M, Takeuchi D, Hamada S, Oishi K, Akeda Y. First human case report of sepsis due to infection with Streptococcus suis serotype 31 in Thailand. BMC Infect Dis 2015; 15:392. [PMID: 26420029 PMCID: PMC4588491 DOI: 10.1186/s12879-015-1136-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 09/21/2015] [Indexed: 01/11/2023] Open
Abstract
Background Streptococcus suis is a zoonotic pathogen that causes invasive infections in humans and pigs. It has been reported that S. suis infection in humans is mostly caused by serotype 2. However, human cases caused by other serotypes have rarely been reported. This is the first report of a human case of infection with S. suis serotype 31 in Thailand. Case presentation A 55-year-old male alcohol misuser with liver cirrhosis was admitted with sepsis to a hospital in the Central Region of Thailand. He had consumed a homemade, raw pork product prior to the onset of illness. He was alive after treatment with ceftriaxone and no complication occurred. An isolate from blood culture at the hospital was suspected as viridans group Streptococcus. It was confirmed at a reference laboratory as S. suis serotype 31 by biochemical tests, 16S rDNA sequencing, and multiplex polymerase chain reaction for serotyping, but it was untypable by the co-agglutination test with antisera against recognized S. suis serotypes, suggesting loss of capsular material. The absence of a capsule was confirmed by transmission electron microscopy. The isolate was confirmed to be sequence type 221, with 13 putative virulence genes that are usually found in serotype 2 strains. Conclusion We should be aware of the emergence of S. suis infections caused by uncommon serotypes in patients with predisposing conditions. Laboratory capacity to identify S. suis in the hospital is needed in developing countries, which can contribute to enhanced surveillance, epidemiological control, and prevention strategies in the prevalent area. Electronic supplementary material The online version of this article (doi:10.1186/s12879-015-1136-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Rujirat Hatrongjit
- Faculty of Science and Engineering, Kasetsart University Chalermphrakiat Sakon Nakhon Province Campus, Muang, Sakon Nakhon Province, 47000, Thailand.
| | - Anusak Kerdsin
- National Institute of Health, Department of Medical Sciences, Ministry of Public Health, Tiwanon Road, Muang, Nonthaburi Province, 11000, Thailand. .,Present address: Faculty of Public Health, Kasetsart University Chalermphrakiat Sakon Nakhon Province Campus, Sakon Nakhon, Thailand.
| | | | - Dan Takeuchi
- Laboratory of Clinical Research on Infectious Diseases, International Research Center for Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka, 565-0871, Japan.
| | - Shigeyuki Hamada
- Thailand-Japan Research Collaboration Center on Emerging and Re-emerging Infections, Nonthaburi Province, Thailand.
| | - Kazunori Oishi
- Infectious Disease Surveillance Center, National Institute of Infectious Diseases, Shinjyuku, Tokyo, Japan.
| | - Yukihiro Akeda
- Laboratory of Clinical Research on Infectious Diseases, International Research Center for Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka, 565-0871, Japan.
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22
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Isolation and characterization of a native avirulent strain of Streptococcus suis serotype 2: a perspective for vaccine development. Sci Rep 2015; 5:9835. [PMID: 25891917 PMCID: PMC4402706 DOI: 10.1038/srep09835] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Accepted: 03/19/2015] [Indexed: 01/05/2023] Open
Abstract
Streptococcus suis, an emerging infectious pathogen, is the cause of two large-scale outbreaks of human streptococcal toxic shock syndrome in China, and has attracted much attention from the scientific community. The genetic basis of its pathogenesis remains enigmatic, and no effective prevention measures have been established. To better understand the virulence differentiation of S. suis and develop a promising vaccine, we isolated and sequenced a native avirulent S. suis strain (05HAS68). Animal experiments revealed that 05HAS68 is an avirulent strain and could protect piglets from the attack of virulent strains. Comparative genomics analyses demonstrated the genetic basis for the lack of virulence in 05HAS68, which is characterized by the absence of some important virulence-associated factors and the intact 89K pathogenicity island. Lack of virulence was also illustrated by reduced survival of 05HAS68 compared to a virulent strain in pig whole blood. Further investigations revealed a large-scale genomic rearrangement in 05HAS68, which was proposed to be mediated by transposase genes and/or prophages. This genomic rearrangement may have caused the genomic diversity of S. suis, and resulted in biological discrepancies between 05HAS68 and highly virulent S. suis strains.
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Pian Y, Wang P, Liu P, Zheng Y, Zhu L, Wang H, Xu B, Yuan Y, Jiang Y. Proteomics identification of novel fibrinogen-binding proteins of Streptococcus suis contributing to antiphagocytosis. Front Cell Infect Microbiol 2015; 5:19. [PMID: 25789245 PMCID: PMC4349166 DOI: 10.3389/fcimb.2015.00019] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2014] [Accepted: 02/17/2015] [Indexed: 12/12/2022] Open
Abstract
Streptococcus suis serotype 2 (SS2) induced sepsis and meningitis are often accompanied by bacteremia. However, the mechanism whereby it helps S. suis to evade PMN-mediated phagocytosis remain unclear. Because of the central roles of bacteria-human fibrinogen (hFg) interaction in innate immunity, here, a proteomics based Far-western blotting (PBFWB) was developed to identify the fibrinogen-binding surface proteins of S. suis (SsFBPs) on a large-scale. And then thirteen potential SsFBPs were identified by PBFWB and we selected seven potential surface proteins to further confirm their binding ability to hFg, of which the gene mutant strains of MRP displayed significantly decrease in binding to immobilized hFg. Additionally, the polyclonal antibodies against Enolase were found to significantly inhibit the binding of SS2 to hFg. Strikingly, MRP and Enolase were found to improve the antiphagocytic ability of SS2 to PMNs by interacting with hFg and enhance the survival of SS2 in human blood. Taken together, the PBFWB method provides useful clues to the bacteria-host interactions. These studies firstly disclose MRP and Enolase were involved in immune evasion of SS2 at least in part by binding to Fg, which make them potential targets for therapies for SS2 infection.
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Affiliation(s)
- Yaya Pian
- State Key Laboratory of Pathogen and Biosecurity, Academy of Military Medical Sciences, Beijing Institute of Microbiology and Epidemiology Beijing China
| | - Pingping Wang
- State Key Laboratory of Pathogen and Biosecurity, Academy of Military Medical Sciences, Beijing Institute of Microbiology and Epidemiology Beijing China
| | - Peng Liu
- State Key Laboratory of Pathogen and Biosecurity, Academy of Military Medical Sciences, Beijing Institute of Microbiology and Epidemiology Beijing China
| | - Yuling Zheng
- State Key Laboratory of Pathogen and Biosecurity, Academy of Military Medical Sciences, Beijing Institute of Microbiology and Epidemiology Beijing China
| | - Li Zhu
- State Key Laboratory of Pathogen and Biosecurity, Academy of Military Medical Sciences, Beijing Institute of Microbiology and Epidemiology Beijing China
| | - Hengliang Wang
- State Key Laboratory of Pathogen and Biosecurity, Academy of Military Medical Sciences, Beijing Institute of Microbiology and Epidemiology Beijing China
| | - Bin Xu
- National Center of Biomedical Analysis, Academy of Military Medical Sciences Beijing, China
| | - Yuan Yuan
- State Key Laboratory of Pathogen and Biosecurity, Academy of Military Medical Sciences, Beijing Institute of Microbiology and Epidemiology Beijing China
| | - Yongqiang Jiang
- State Key Laboratory of Pathogen and Biosecurity, Academy of Military Medical Sciences, Beijing Institute of Microbiology and Epidemiology Beijing China
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24
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Fan X, Wang X, Li N, Cui H, Hou B, Gao B, Cleary PP, Wang B. Sortase A induces Th17-mediated and antibody-independent immunity to heterologous serotypes of group A streptococci. PLoS One 2014; 9:e107638. [PMID: 25232948 PMCID: PMC4169422 DOI: 10.1371/journal.pone.0107638] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Accepted: 08/17/2014] [Indexed: 01/01/2023] Open
Abstract
Group A streptococci (GAS) are associated with a variety of mucosal and invasive human infections. Recurrent infections by highly heterologous serotypes indicate that cross-serotype immunity is critical for prevention of GAS infections; however, mechanisms underlying serotype-independent protection are poorly understood. Here we report that intranasal vaccination of mice with Sortase A (SrtA), a conserved cell wall bound protein, reduced colonization of nasal-associated lymphoid tissue (NALT) by heterologous serotypes of GAS. Vaccination significantly increased CD4+ IL-17A+ cells in NALT and depletion of IL-17A by neutralizing antibody prevented GAS clearance from NALT which was dependent on immunization with SrtA. Vaccination also induced high levels of SrtA-specific antibodies; however, immunized, B cell-deficient mice cleared streptococcal challenges as efficiently as wild type mice, indicating that the cross-serotype protection is Th17-biased and antibody-independent. Furthermore, efficient GAS clearance from NALT was associated with a rapid neutrophil influx into NALT of immunized mice. These results suggest that serotype independent immune protection against GAS mucosal infection can be achieved by intranasal vaccination with SrtA and enhanced neutrophil function is critical for anti-GAS defense and might be a target for prevention of GAS infections.
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Affiliation(s)
- Xin Fan
- Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Beijing, China
| | - Xiaoshuang Wang
- Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Beijing, China
| | - Ning Li
- Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Beijing, China
| | - Honglian Cui
- Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Beijing, China
| | - Baidong Hou
- Key Laboratory of Infection and Immunity, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Bin Gao
- Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Beijing, China
| | - Paul Patrick Cleary
- Department of Microbiology, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Beinan Wang
- Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Beijing, China
- * E-mail:
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25
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Bi Y, Li J, Yang L, Zhang S, Li Y, Jia X, Sun L, Yin Y, Qin C, Wang B, Gao GF, Liu W. Assessment of the pathogenesis of Streptococcus suis type 2 infection in piglets for understanding streptococcal toxic shock-like syndrome, meningitis, and sequelae. Vet Microbiol 2014; 173:299-309. [PMID: 25200597 DOI: 10.1016/j.vetmic.2014.08.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2014] [Revised: 08/03/2014] [Accepted: 08/09/2014] [Indexed: 01/29/2023]
Abstract
Streptococcus suis type 2 (SS2) is an zoonotic pathogen that had caused outbreaks in 1998 and 2005 in China. It is still not very clear how the disease progresses into the streptococcal toxic shock-like syndrome (STSLS) or meningitis, as well as the sequelae from the survivals. The present study used piglets as infection model to systematically investigate the pathogenesis of the infection caused by the SS2 strain 05ZYH33. The infected piglets showed joint swelling, lameness, and crouch at beginning, then developed into septic-like shock syndrome (SLSS) or prostration syndrome, at last the survivals showed physical activity impairment. The morbidity and mortality were 100% (71% for SLSS, 29% for prostration syndrome) and 29%, respectively. The pigs exhibiting SLSS had deep invasive infections in tissues and organs, and displayed more severe bacteremia and cytokine secretion in the bloodstream and organs than pigs with prostration syndrome. Moreover, the polymorphisms in the toll-like receptor 1 (TLR1) and TLR2 genes varied between the pigs affected with SLSS and prostration syndrome. Several lines of evidence indicated that SS2 infection progression into SLSS or relatively lighter prostration syndrome in pigs is closely related to the degrees of bacteremia and cytokine storm, which may be inherently determined by the diversity of innate immunity-associated genes. Furthermore, brain lesions, such as venous thrombosis, may directly contribute to the sequelae in human cases, were identified in the pigs. These results might help us to further understand the pathogenesis of SS2 in humans.
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Affiliation(s)
- Yuhai Bi
- Chinese Academy of Sciences Key Laboratory of Pathogenic Microbiology and Immunology (CASPMI), Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Jing Li
- Chinese Academy of Sciences Key Laboratory of Pathogenic Microbiology and Immunology (CASPMI), Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Limin Yang
- Chinese Academy of Sciences Key Laboratory of Pathogenic Microbiology and Immunology (CASPMI), Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Shuang Zhang
- Chinese Academy of Sciences Key Laboratory of Pathogenic Microbiology and Immunology (CASPMI), Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yun Li
- Chinese Academy of Sciences Key Laboratory of Pathogenic Microbiology and Immunology (CASPMI), Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Xiaojuan Jia
- Chinese Academy of Sciences Key Laboratory of Pathogenic Microbiology and Immunology (CASPMI), Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Lei Sun
- Chinese Academy of Sciences Key Laboratory of Pathogenic Microbiology and Immunology (CASPMI), Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yanbo Yin
- College of Animal Science and Veterinary Medicine, Qingdao Agricultural University, Qingdao 266109, China
| | - Chuan Qin
- Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences (CAMS) & Comparative Medicine Center, Peking Union Medical Collage (PUMC), Beijing 100021, China
| | - Beinan Wang
- Chinese Academy of Sciences Key Laboratory of Pathogenic Microbiology and Immunology (CASPMI), Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - George Fu Gao
- Chinese Academy of Sciences Key Laboratory of Pathogenic Microbiology and Immunology (CASPMI), Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; Office of Director-General, Chinese Center for Disease Control and Prevention, Beijing 102206, China
| | - Wenjun Liu
- Chinese Academy of Sciences Key Laboratory of Pathogenic Microbiology and Immunology (CASPMI), Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.
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Wu Z, Wu C, Shao J, Zhu Z, Wang W, Zhang W, Tang M, Pei N, Fan H, Li J, Yao H, Gu H, Xu X, Lu C. The Streptococcus suis transcriptional landscape reveals adaptation mechanisms in pig blood and cerebrospinal fluid. RNA (NEW YORK, N.Y.) 2014; 20:882-898. [PMID: 24759092 PMCID: PMC4024642 DOI: 10.1261/rna.041822.113] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2013] [Accepted: 03/11/2014] [Indexed: 06/03/2023]
Abstract
Streptococcus suis (SS) is an important pathogen of pigs, and it is also recognized as a zoonotic agent for humans. SS infection may result in septicemia or meningitis in the host. However, little is known about genes that contribute to the virulence process and survival within host blood or cerebrospinal fluid (CSF). Small RNAs (sRNA) have emerged as key regulators of virulence in several bacteria, but they have not been investigated in SS. Here, using a differential RNA-sequencing approach and RNAs from SS strain P1/7 grown in rich medium, pig blood, or CSF, we present the SS genome-wide map of 793 transcriptional start sites and 370 operons. In addition to identifying 29 sRNAs, we show that five sRNA deletion mutants attenuate SS virulence in a zebrafish infection model. Homology searches revealed that 10 sRNAs were predicted to be present in other pathogenic Streptococcus species. Compared with wild-type strain P1/7, sRNAs rss03, rss05, and rss06 deletion mutants were significantly more sensitive to killing by pig blood. It is possible that rss06 contributes to SS virulence by indirectly activating expression of SSU0308, a virulence gene encoding a zinc-binding lipoprotein. In blood, genes involved in the synthesis of capsular polysaccharide (CPS) and subversion of host defenses were up-regulated. In contrast, in CSF, genes for CPS synthesis were down-regulated. Our study is the first analysis of SS sRNAs involved in virulence and has both improved our understanding of SS pathogenesis and increased the number of sRNAs known to play definitive roles in bacterial virulence.
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Affiliation(s)
- Zongfu Wu
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
- Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210095, China
- OIE Reference Laboratory for Swine Streptococcosis, Nanjing 210095, China
| | | | - Jing Shao
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
- Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210095, China
- OIE Reference Laboratory for Swine Streptococcosis, Nanjing 210095, China
| | | | - Weixue Wang
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
- Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210095, China
- OIE Reference Laboratory for Swine Streptococcosis, Nanjing 210095, China
| | | | - Min Tang
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
- Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210095, China
- OIE Reference Laboratory for Swine Streptococcosis, Nanjing 210095, China
| | - Na Pei
- BGI-Shenzhen, Shenzhen 518083, China
| | - Hongjie Fan
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
- Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210095, China
- OIE Reference Laboratory for Swine Streptococcosis, Nanjing 210095, China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
| | | | - Huochun Yao
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
- Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210095, China
- OIE Reference Laboratory for Swine Streptococcosis, Nanjing 210095, China
| | - Hongwei Gu
- Jiangsu Engineering Research Center for microRNA Biology and Biotechnology, State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210093, China
| | - Xun Xu
- BGI-Shenzhen, Shenzhen 518083, China
| | - Chengping Lu
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
- Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210095, China
- OIE Reference Laboratory for Swine Streptococcosis, Nanjing 210095, China
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27
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Tang Y, Zhang X, Yin Y, Hardwidge PR, Fang W. Streptococcus suis type 2 SSU0587 protein is a beta-galactosidase that contributes to bacterial adhesion but not to virulence in mice. J Vet Med Sci 2014; 76:1055-9. [PMID: 24670993 PMCID: PMC4143649 DOI: 10.1292/jvms.13-0625] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Bacterial surface proteins play key roles in virulence and often contribute to bacterial adhesion and invasion. We discovered that the Streptococcus suis type 2 (SS2) gene SSU0587 encodes a protein of 1,491 amino acids that possesses β-galactosidase activity. The surface association of the protein was dependent upon sortase activity. Deleting SSU0587 from clinical SS2 isolate JX081101 caused a loss of both β-galactosidase activity and adherence to microvascular endothelial cells. Deleting SSU0587 had no measurable impact on either invasion of microvascular endothelial cells or on virulence in a murine infection model, although the concentration of JX081101ΔSSU0587 was reduced in the brains of infected mice, as compared with the pathogen loads of the wild-type strain.
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Affiliation(s)
- Yulong Tang
- Institute of Subtropical Agriculture, Chinese Academy of Sciences, Research Center of Healthy Breeding Livestock & Poultry, Hunan Engineering & Research Center of Animal & Poultry Science, Key Lab Agro-ecology Processing Subtropical Region, Scientific Observational and Experimental Station of Animal Nutrition and Feed Science in South-Central China, Ministry of Agriculture, Changsha, Hunan, People's Republic of China
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28
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Feng Y, Zhang H, Wu Z, Wang S, Cao M, Hu D, Wang C. Streptococcus suis infection: an emerging/reemerging challenge of bacterial infectious diseases? Virulence 2014; 5:477-97. [PMID: 24667807 PMCID: PMC4063810 DOI: 10.4161/viru.28595] [Citation(s) in RCA: 158] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Streptococcus suis (S. suis) is a family of pathogenic gram-positive bacterial strains that represents a primary health problem in the swine industry worldwide. S. suis is also an emerging zoonotic pathogen that causes severe human infections clinically featuring with varied diseases/syndromes (such as meningitis, septicemia, and arthritis). Over the past few decades, continued efforts have made significant progress toward better understanding this zoonotic infectious entity, contributing in part to the elucidation of the molecular mechanism underlying its high pathogenicity. This review is aimed at presenting an updated overview of this pathogen from the perspective of molecular epidemiology, clinical diagnosis and typing, virulence mechanism, and protective antigens contributing to its zoonosis.
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Affiliation(s)
- Youjun Feng
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases & State Key Laboratory for Diagnosis and Treatment of Infectious Disease; First Affiliated Hospital; Zhejiang University School of Medicine; Hangzhou, Zhejiang, PR China; Department of Medical Microbiology and Parasitology; Zhejiang University School of Medicine; Hangzhou, Zhejiang, PR China
| | - Huimin Zhang
- University of Illinois at Urbana-Champaign (UIUC); Urbana, IL USA
| | - Zuowei Wu
- Department of Veterinary Microbiology and Preventive Medicine; Iowa State University; Ames, IA USA
| | - Shihua Wang
- College of Life Sciences; Fujian Agriculture and Forestry University; Fuzhou, Fujian, PR China
| | - Min Cao
- Department of Epidemiology; Research Institute for Medicine of Nanjing Command; Nanjing, Jiangsu, PR China
| | - Dan Hu
- Department of Epidemiology; Research Institute for Medicine of Nanjing Command; Nanjing, Jiangsu, PR China
| | - Changjun Wang
- Department of Epidemiology; Research Institute for Medicine of Nanjing Command; Nanjing, Jiangsu, PR China
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29
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Du B, Ji W, An H, Shi Y, Huang Q, Cheng Y, Fu Q, Wang H, Yan Y, Sun J. Functional analysis of c-di-AMP phosphodiesterase, GdpP, in Streptococcus suis serotype 2. Microbiol Res 2014; 169:749-58. [PMID: 24680501 DOI: 10.1016/j.micres.2014.01.002] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Revised: 01/19/2014] [Accepted: 01/19/2014] [Indexed: 12/25/2022]
Abstract
Streptococcus suis serotype 2 (SS2) is an important zoonotic pathogen that causes serious diseases in pigs and humans. GdpP protein is a recently discovered specific phosphodiesterase that degrades cyclic diadenosine monophosphate (c-di-AMP). It is widely distributed among the firmicutes phylum and altered expression of GdpP is associated with several phenotypes in various bacterial strains. We investigated the role of GdpP in physiology and virulence in SS2. An in-frame mutant of gdpP was constructed using homologous recombination and bacterial growth, biofilm formation, hemolytic activity, cell adherence and invasion, expression of virulence factors, and virulence were evaluated. Disruption of gdpP increased intracellular c-di-AMP level and affected growth and increased biofilm formation of SS2. Simultaneously, the gdpP mutant strain exhibited a significant decrease in hemolytic activity and adherence to and invasion of HEp-2 cells compared with the parental strain. Quantitative reverse transcriptase polymerase chain reaction indicated significantly reduced expression of the known virulence genes cps2, sly, fpbs, mrp, ef and gdh in the gdpP mutant. In murine infection models, the gdpP mutant strain was attenuated, and impaired bacterial growth was observed in specific organs. All these findings revealed a significant contribution of gdpP and its substrate (c-di-AMP) to the biology and virulence of SS2.
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Affiliation(s)
- Bin Du
- Department of Animal Science, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai Key Laboratory of Veterinary Biotechnology, Key Laboratory of Urban Agriculture (South) Ministry of Agriculture, Shanghai 200240, PR China
| | - Wenhui Ji
- Department of Animal Science, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai Key Laboratory of Veterinary Biotechnology, Key Laboratory of Urban Agriculture (South) Ministry of Agriculture, Shanghai 200240, PR China
| | - Huiting An
- Department of Animal Science, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai Key Laboratory of Veterinary Biotechnology, Key Laboratory of Urban Agriculture (South) Ministry of Agriculture, Shanghai 200240, PR China
| | - Yibo Shi
- Department of Animal Science, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai Key Laboratory of Veterinary Biotechnology, Key Laboratory of Urban Agriculture (South) Ministry of Agriculture, Shanghai 200240, PR China
| | - Qingqing Huang
- Department of Animal Science, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai Key Laboratory of Veterinary Biotechnology, Key Laboratory of Urban Agriculture (South) Ministry of Agriculture, Shanghai 200240, PR China
| | - Yuqiang Cheng
- Department of Animal Science, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai Key Laboratory of Veterinary Biotechnology, Key Laboratory of Urban Agriculture (South) Ministry of Agriculture, Shanghai 200240, PR China
| | - Qiang Fu
- Department of Animal Science, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai Key Laboratory of Veterinary Biotechnology, Key Laboratory of Urban Agriculture (South) Ministry of Agriculture, Shanghai 200240, PR China
| | - Hengan Wang
- Department of Animal Science, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai Key Laboratory of Veterinary Biotechnology, Key Laboratory of Urban Agriculture (South) Ministry of Agriculture, Shanghai 200240, PR China
| | - Yaxian Yan
- Department of Animal Science, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai Key Laboratory of Veterinary Biotechnology, Key Laboratory of Urban Agriculture (South) Ministry of Agriculture, Shanghai 200240, PR China.
| | - Jianhe Sun
- Department of Animal Science, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai Key Laboratory of Veterinary Biotechnology, Key Laboratory of Urban Agriculture (South) Ministry of Agriculture, Shanghai 200240, PR China.
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30
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Wu Z, Wang W, Tang M, Shao J, Dai C, Zhang W, Fan H, Yao H, Zong J, Chen D, Wang J, Lu C. Comparative genomic analysis shows that Streptococcus suis meningitis isolate SC070731 contains a unique 105K genomic island. Gene 2013; 535:156-64. [PMID: 24316490 DOI: 10.1016/j.gene.2013.11.044] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2013] [Revised: 11/16/2013] [Accepted: 11/19/2013] [Indexed: 11/29/2022]
Abstract
Streptococcus suis (SS) is an important swine pathogen worldwide that occasionally causes serious infections in humans. SS infection may result in meningitis in pigs and humans. The pathogenic mechanisms of SS are poorly understood. Here, we provide the complete genome sequence of S. suis serotype 2 (SS2) strain SC070731 isolated from a pig with meningitis. The chromosome is 2,138,568bp in length. There are 1933 predicted protein coding sequences and 96.7% (57/59) of the known virulence-associated genes are present in the genome. Strain SC070731 showed similar virulence with SS2 virulent strains HA9801 and ZY05719, but was more virulent than SS2 virulent strain P1/7 in the zebrafish infection model. Comparative genomic analysis revealed a unique 105K genomic island in strain SC070731 that is absent in seven other sequenced SS2 strains. Further analysis of the 105K genomic island indicated that it contained a complete nisin locus similar to the nisin U locus in S. uberis strain 42, a prophage similar to S. oralis phage PH10 and several antibiotic resistance genes. Several proteins in the 105K genomic island, including nisin and RelBE toxin-antitoxin system, contribute to the bacterial fitness and virulence in other pathogenic bacteria. Further investigation of newly identified gene products, including four putative new virulence-associated surface proteins, will improve our understanding of SS pathogenesis.
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Affiliation(s)
- Zongfu Wu
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210095, China; OIE Reference Lab for Swine Streptococcosis, Nanjing 210095, China.
| | - Weixue Wang
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210095, China; OIE Reference Lab for Swine Streptococcosis, Nanjing 210095, China
| | - Min Tang
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210095, China; OIE Reference Lab for Swine Streptococcosis, Nanjing 210095, China
| | - Jing Shao
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210095, China; OIE Reference Lab for Swine Streptococcosis, Nanjing 210095, China
| | - Chen Dai
- Experimental Teaching Center of Life Science, Nanjing Agricultural University, Nanjing 210095, China
| | - Wei Zhang
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210095, China; OIE Reference Lab for Swine Streptococcosis, Nanjing 210095, China
| | - Hongjie Fan
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210095, China; OIE Reference Lab for Swine Streptococcosis, Nanjing 210095, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
| | - Huochun Yao
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210095, China; OIE Reference Lab for Swine Streptococcosis, Nanjing 210095, China
| | - Jie Zong
- Novel Bioinformatics Co., Ltd, Shanghai, China
| | - Dai Chen
- Novel Bioinformatics Co., Ltd, Shanghai, China
| | | | - Chengping Lu
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210095, China; OIE Reference Lab for Swine Streptococcosis, Nanjing 210095, China.
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31
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Whole-Genome Sequence of Streptococcus suis Serotype 3 Strain YB51. GENOME ANNOUNCEMENTS 2013; 1:1/6/e00884-13. [PMID: 24179118 PMCID: PMC3814634 DOI: 10.1128/genomea.00884-13] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We report here the second complete genome sequence of Streptococcus suis serotype 3 (strain YB51). The genome is 2,043,655 bp in length, which is 14,840 bp longer than the first reported genome of the same serotype, and it covers 2,012 coding sequences, 56 tRNAs, and 4 rRNA loci.
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32
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Kouki A, Pieters RJ, Nilsson UJ, Loimaranta V, Finne J, Haataja S. Bacterial Adhesion of Streptococcus suis to Host Cells and Its Inhibition by Carbohydrate Ligands. BIOLOGY 2013; 2:918-35. [PMID: 24833053 PMCID: PMC3960878 DOI: 10.3390/biology2030918] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Revised: 05/22/2013] [Accepted: 05/22/2013] [Indexed: 11/16/2022]
Abstract
Streptococcus suis is a Gram-positive bacterium, which causes sepsis and meningitis in pigs and humans. This review examines the role of known S. suis virulence factors in adhesion and S. suis carbohydrate-based adhesion mechanisms, as well as the inhibition of S. suis adhesion by anti-adhesion compounds in in vitro assays. Carbohydrate-binding specificities of S. suis have been identified, and these studies have shown that many strains recognize Galα1-4Gal-containing oligosaccharides present in host glycolipids. In the era of increasing antibiotic resistance, new means to treat infections are needed. Since microbial adhesion to carbohydrates is important to establish disease, compounds blocking adhesion could be an alternative to antibiotics. The use of oligosaccharides as drugs is generally hampered by their relatively low affinity (micromolar) to compete with multivalent binding to host receptors. However, screening of a library of chemically modified Galα1-4Gal derivatives has identified compounds that inhibit S. suis adhesion in nanomolar range. Also, design of multivalent Galα1-4Gal-containing dendrimers has resulted in a significant increase of the inhibitory potency of the disaccharide. The S. suis adhesin binding to Galα1-4Gal-oligosaccharides, Streptococcal adhesin P (SadP), was recently identified. It has a Galα1-4Gal-binding N-terminal domain and a C-terminal LPNTG-motif for cell wall anchoring. The carbohydrate-binding domain has no homology to E. coli P fimbrial adhesin, which suggests that these Gram-positive and Gram-negative bacterial adhesins recognizing the same receptor have evolved by convergent evolution. SadP adhesin may represent a promising target for the design of anti-adhesion ligands for the prevention and treatment of S. suis infections.
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Affiliation(s)
- Annika Kouki
- Department of Medical Biochemistry and Genetics, University of Turku, Kiinamyllynkatu 10, Turku FI-20520, Finland.
| | - Roland J Pieters
- Department of Medicinal Chemistry and Chemical Biology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, P.O. Box 80082, Utrecht 3508 TB, The Netherlands.
| | - Ulf J Nilsson
- Centre for Analysis and Synthesis, Department of Chemistry, Lund University, POB 124, Lund SE-22100, Sweden.
| | - Vuokko Loimaranta
- Department of Medical Biochemistry and Genetics, University of Turku, Kiinamyllynkatu 10, Turku FI-20520, Finland.
| | - Jukka Finne
- Department of Biosciences, Division of Biochemistry and Biotechnology, University of Helsinki, P.O.B. 56, Helsinki FI-00014, Finland.
| | - Sauli Haataja
- Department of Medical Biochemistry and Genetics, University of Turku, Kiinamyllynkatu 10, Turku FI-20520, Finland.
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Complete Genome Sequence of Streptococcus suis Serotype 16 Strain TL13. GENOME ANNOUNCEMENTS 2013; 1:1/3/e00394-13. [PMID: 23814033 PMCID: PMC3695429 DOI: 10.1128/genomea.00394-13] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We report here the first complete genome sequence of Streptococcus suis serotype 16, which has been identified to be zoonotic. The sequenced strain TL13 was isolated from a pig in China. The genome is 2,038,146 bp in length, covering 1,950 coding sequences, 53 tRNAs, and 4 rRNA loci.
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Sánchez del Rey V, Fernández-Garayzábal JF, Briones V, Iriso A, Domínguez L, Gottschalk M, Vela AI. Genetic analysis of Streptococcus suis isolates from wild rabbits. Vet Microbiol 2013; 165:483-6. [PMID: 23725747 DOI: 10.1016/j.vetmic.2013.04.025] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Revised: 04/25/2013] [Accepted: 04/29/2013] [Indexed: 11/29/2022]
Abstract
This work aims to investigate the presence of Streptococcus suis in wild rabbits. A total of 65 S. suis isolates were recovered from 33.3% of the wild rabbits examined. Most isolates (86.2%) belong to genotype cps9. These isolates were further characterized by pulsed field gel electrophoresis (PFGE), multilocus sequence typing (MLST) and virulence genotyping. Overall, S. suis exhibited a low genetic diversity. Only 5 genetic profiles were obtained by PFGE and most isolates (71.4%) were included in two pulsotypes that were also widely distributed among the wild rabbit population. MLST analysis assigned all cps9 isolates into three new singlestones (ST216, ST217 and ST284), which were not genetically related to the European ST87 and Spanish ST61 widespread swine clones, indicating a different genetic background for the S. suis isolates from wild rabbits and pigs. Wild rabbit isolates exhibited the genotype mrp-/epf-/sly-, different from those showed by most of the swine S. suis isolates of the ST87 and ST61 clones. None of the S. suis isolated from wild rabbits exhibited the genotype cps2/mrp+/epf+/sly+ associated with human infections. These results indicate that S. suis isolates from wild rabbits are not genetically related with prevalent clones usually associated with infections in pigs or humans in Europe and do not exhibit either their virulence genotypes. Therefore, although wild rabbits could represent an unknown reservoir of this pathogen, they could not represent a potential risk for pigs or humans.
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Affiliation(s)
- V Sánchez del Rey
- Centro de Vigilancia Sanitaria Veterinaria (VISAVET), Universidad Complutense, 28040 Madrid, Spain
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Tang Y, Wu W, Zhang X, Lu Z, Chen J, Fang W. Catabolite control protein A of Streptococcus suis type 2 contributes to sugar metabolism and virulence. J Microbiol 2012; 50:994-1002. [PMID: 23274986 DOI: 10.1007/s12275-012-2035-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2012] [Accepted: 08/21/2012] [Indexed: 10/27/2022]
Abstract
Catabolite control protein A (CcpA) is the major transcriptional regulator in carbon catabolite repression in several Gram-positive bacteria. We attempted to characterize the role of a CcpA homologue of Streptococcus suis type 2 in sugar metabolism and virulence. Addition of glucose or sucrose to the defined medium significantly reduced the activity of raffinose-inducible α-galactosidase, cellobiose-inducible β-glucosidase, and maltose-inducible α-glucosidase of the wild-type strain by about 9, 4, and 2-3 fold, respectively. Deletion of ccpA substantially derepressed the effects of repressing sugars on α-galactosidase or β-glucosidase activity. The ccpA deletion mutant showed reduced expression of virulence genes sly and eno (P<0.05), decreased adhesion to and invasion into endothelial cells (P<0.05), and attenuated virulence to mice with significant reduction of death rate and bacterial burden in organs, as compared to the wild-type strain. Both the in vitro and in vivo defect phenotypes were reversible by ccpA complementation. Thus, this study shows that CcpA of S. suis type 2 plays an important role in carbon catabolite repression and virulence.
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Affiliation(s)
- Yulong Tang
- Institute of Preventive Veterinary Medicine and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Zhejiang University, Hangzhou 310058, PR China
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36
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Abstract
Enolase is a conserved cytoplasmic metalloenzyme existing universally in both eukaryotic and prokaryotic cells. The enzyme can also locate on the cell surface and bind to plasminogen, via which contributing to the mucosal surface localization of the bacterial pathogens and assisting the invasion into the host cells. The functions of the eukaryotic enzymes on the cell surface expression (including T cells, B cells, neutrophils, monocytoes, neuronal cells and epithelial cells) are not known. Streptococcus suis serotype 2 (S. suis 2, SS2) is an important zoonotic pathogen which has recently caused two large-scale outbreaks in southern China with severe streptococcal toxic shock syndrome (STSS) never seen before in human sufferers. We recently identified the SS2 enolase as an important protective antigen which could protect mice from fatal S.suis 2 infection. In this study, a 2.4-angstrom structure of the SS2 enolase is solved, revealing an octameric arrangement in the crystal. We further demonstrated that the enzyme exists exclusively as an octamer in solution via a sedimentation assay. These results indicate that the octamer is the biological unit of SS2 enolase at least in vitro and most likely in vivo as well. This is, to our knowledge, the first comprehensive characterization of the SS2 enolase octamer both structurally and biophysically, and the second octamer enolase structure in addition to that of Streptococcus pneumoniae. We also investigated the plasminogen binding property of the SS2 enzyme.
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37
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Attenuation of Streptococcus suis virulence by the alteration of bacterial surface architecture. Sci Rep 2012; 2:710. [PMID: 23050094 PMCID: PMC3464449 DOI: 10.1038/srep00710] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Accepted: 09/14/2012] [Indexed: 01/09/2023] Open
Abstract
NeuB, a sialic acid synthase catalyzes the last committed step of the de novo biosynthetic pathway of sialic acid, a major element of bacterial surface structure. Here we report a functional NeuB homologue of Streptococcus suis, a zoonotic agent, and systematically address its molecular and immunological role in bacterial virulence. Disruption of neuB led to thinner capsules and more susceptibility to pH, and cps2B inactivation resulted in complete absence of capsular polysaccharides. These two mutants both exhibited increased adhesion and invasion to Hep-2 cells and improved sensibility to phagocytosis. Not only do they retain the capability of inducing the release of host pro-inflammatory cytokines, but also result in the faster secretion of IL-8. Easier cleaning up of the mutant strains in whole blood is consistent with virulence attenuation seen with experimental infections of both mice and SPF-piglets. Therefore we concluded that altered architecture of S. suis surface attenuates its virulence.
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Inactivation of the sodA gene of Streptococcus suis type 2 encoding superoxide dismutase leads to reduced virulence to mice. Vet Microbiol 2012; 158:360-6. [DOI: 10.1016/j.vetmic.2012.02.028] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2012] [Revised: 02/19/2012] [Accepted: 02/20/2012] [Indexed: 12/23/2022]
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Fittipaldi N, Segura M, Grenier D, Gottschalk M. Virulence factors involved in the pathogenesis of the infection caused by the swine pathogen and zoonotic agent Streptococcus suis. Future Microbiol 2012; 7:259-79. [PMID: 22324994 DOI: 10.2217/fmb.11.149] [Citation(s) in RCA: 312] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Streptococcus suis is a major swine pathogen responsible for important economic losses to the swine industry worldwide. It is also an emerging zoonotic agent of meningitis and streptococcal toxic shock-like syndrome. Since the recent recognition of the high prevalence of S. suis human disease in southeast and east Asia, the interest of the scientific community in this pathogen has significantly increased. In the last few years, as a direct consequence of these intensified research efforts, large amounts of data on putative virulence factors have appeared in the literature. Although the presence of some proposed virulence factors does not necessarily define a S. suis strain as being virulent, several cell-associated or secreted factors are clearly important for the pathogenesis of the S. suis infection. In order to cause disease, S. suis must colonize the host, breach epithelial barriers, reach and survive in the bloodstream, invade different organs, and cause exaggerated inflammation. In this review, we discuss the potential contribution of different described S. suis virulence factors at each step of the pathogenesis of the infection. Finally, we briefly discuss other described virulence factors, virulence factor candidates and virulence markers for which a precise role at specific steps of the pathogenesis of the S. suis infection has not yet been clearly established.
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Affiliation(s)
- Nahuel Fittipaldi
- Groupe de Recherche sur les Maladies Infectieuses du Porc & Centre de Recherche en Infectiologie Porcine, Faculté de médecine vétérinaire, Université de Montréal, 3200 rue Sicotte, CP5000, St-Hyacinthe, Quebec, J2S 7C6, Canada
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Fhb, a novel factor H-binding surface protein, contributes to the antiphagocytic ability and virulence of Streptococcus suis. Infect Immun 2012; 80:2402-13. [PMID: 22526676 DOI: 10.1128/iai.06294-11] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Streptococcus suis serotype 2 is a Gram-positive bacterium that causes sepsis and meningitis in piglets and humans. The mechanisms of S. suis serotype 2 invasive disease are not well understood. The surface proteins of pathogens usually play important roles in infection and bacterium-host interactions. Here, we identified a novel surface protein that contributed significantly to the virulence of S. suis serotype 2 in a piglet infection model. This protein showed little similarity to other reported proteins and exhibited strong binding activity to human factor H (hFH). It was designated Fhb (factor H-binding protein). The fhb genes found in S. suis serotypes 1, 2, 4, 7, and 9 exhibited molecular polymorphism. Fhb possessed two proline-rich repeat sequences and XPZ domains, and one repeat sequence exhibited a high homology to Bac, an IgA-binding protein of Streptococcus agalactiae. Evidence strongly indicated that fhb-deficient mutants had diminished phagocytosis resistance in bactericidal assays. In addition, Fhb plays important roles in complement-mediated immunity by interacting with hFH. These findings indicated that Fhb is a crucial surface protein contributing to the virulence of S. suis, with important functions in evading innate immune defenses by interaction with host complement regulatory factor hFH.
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Chang OK, Perrin C, Galia W, Saulnier F, Miclo L, Roux E, Driou A, Humbert G, Dary A. Release of the cell-envelope protease PrtS in the growth medium of Streptococcus thermophilus 4F44. Int Dairy J 2012. [DOI: 10.1016/j.idairyj.2011.10.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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42
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Movert E, Wu Y, Lambeau G, Touqui L, Areschoug T. A novel bacterial resistance mechanism against human group IIA-secreted phospholipase A2: role of Streptococcus pyogenes sortase A. THE JOURNAL OF IMMUNOLOGY 2011; 187:6437-46. [PMID: 22075700 DOI: 10.4049/jimmunol.1100499] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Human group IIA-secreted phospholipase A(2) (sPLA(2)-IIA) is a bactericidal molecule important for the innate immune defense against Gram-positive bacteria. In this study, we analyzed its role in the host defense against Streptococcus pyogenes, a major human pathogen, and demonstrated that this bacterium has evolved a previously unidentified mechanism to resist killing by sPLA(2)-IIA. Analysis of a set of clinical isolates demonstrated that an ~500-fold higher concentration of sPLA(2)-IIA was required to kill S. pyogenes compared with strains of the group B Streptococcus, which previously were shown to be sensitive to sPLA(2)-IIA, indicating that S. pyogenes exhibits a high degree of resistance to sPLA(2)-IIA. We found that an S. pyogenes mutant lacking sortase A, a transpeptidase responsible for anchoring LPXTG proteins to the cell wall in Gram-positive bacteria, was significantly more sensitive (~30-fold) to sPLA(2)-IIA compared with the parental strain, indicating that one or more LPXTG surface proteins protect S. pyogenes against sPLA(2)-IIA. Importantly, using transgenic mice expressing human sPLA(2)-IIA, we showed that the sortase A-mediated sPLA(2)-IIA resistance mechanism in S. pyogenes also occurs in vivo. Moreover, in this mouse model, we also showed that human sPLA(2)-IIA is important for the defense against lethal S. pyogenes infection. Thus, we demonstrated a novel mechanism by which a pathogenic bacterium can evade the bactericidal action of sPLA(2)-IIA and we showed that sPLA(2)-IIA contributes to the host defense against S. pyogenes infection.
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Affiliation(s)
- Elin Movert
- Division of Medical Microbiology, Department of Laboratory Medicine, Lund University, 22362 Lund, Sweden
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Wu Z, Zhang W, Shao J, Wang Y, Lu Y, Lu C. Immunoproteomic assay of secreted proteins of Streptococcus suis serotype 9 with convalescent sera from pigs. Folia Microbiol (Praha) 2011; 56:423-30. [DOI: 10.1007/s12223-011-0065-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2011] [Accepted: 08/25/2011] [Indexed: 10/17/2022]
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Abstract
Streptococcus suis is a zoonotic pathogen causing economic loss in the swine industry and is also a threat to human health. To date, the mechanism of pathogenesis is not fully understood. Here, we report the complete genome sequence of S. suis strain ST3 of serotype 3, which provides opportunities to reveal genetic basis of infection of S. suis non-serotype 2 strains.
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Wu Z, Li M, Wang C, Li J, Lu N, Zhang R, Jiang Y, Yang R, Liu C, Liao H, Gao GF, Tang J, Zhu B. Probing genomic diversity and evolution of Streptococcus suis serotype 2 by NimbleGen tiling arrays. BMC Genomics 2011; 12:219. [PMID: 21554741 PMCID: PMC3118785 DOI: 10.1186/1471-2164-12-219] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2010] [Accepted: 05/10/2011] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Our previous studies revealed that a new disease form of streptococcal toxic shock syndrome (STSS) is associated with specific Streptococcus suis serotype 2 (SS2) strains. To achieve a better understanding of the pathogenicity and evolution of SS2 at the whole-genome level, comparative genomic analysis of 18 SS2 strains, selected on the basis of virulence and geographic origin, was performed using NimbleGen tiling arrays. RESULTS Our results demonstrate that SS2 isolates have highly divergent genomes. The 89K pathogenicity island (PAI), which has been previously recognized as unique to the Chinese epidemic strains causing STSS, was partially included in some other virulent and avirulent strains. The ABC-type transport systems, encoded by 89K, were hypothesized to greatly contribute to the catastrophic features of STSS. Moreover, we identified many polymorphisms in genes encoding candidate or known virulence factors, such as PlcR, lipase, sortases, the pilus-associated proteins, and the response regulator RevS and CtsR. On the basis of analysis of regions of differences (RDs) across the entire genome for the 18 selected SS2 strains, a model of microevolution for these strains is proposed, which provides clues into Streptococcus pathogenicity and evolution. CONCLUSIONS Our deep comparative genomic analysis of the 89K PAI present in the genome of SS2 strains revealed details into how some virulent strains acquired genes that may contribute to STSS, which may lead to better environmental monitoring of epidemic SS2 strains.
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Affiliation(s)
- Zuowei Wu
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
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Abstract
Streptococcus suis is an important zoonotic agent leading to a variety of diseases in swine and can be transmitted to human beings upon close contact. Here, we report the complete genome sequence of S. suis serotype 14 strain JS14 which was isolated from a diseased pig in Jiangsu Province, China.
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Contribution of the Rgg transcription regulator to metabolism and virulence of Streptococcus suis serotype 2. Infect Immun 2010; 79:1319-28. [PMID: 21149588 DOI: 10.1128/iai.00193-10] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Rgg-like regulators, a family of transcription factors commonly found in many Gram-positive bacteria, play multiple roles, especially in the control of pathogen virulence. Here, we report an rgg homologue from a Chinese isolate, 05ZYH33, of Streptococcus suis serotype 2 (SS2). Deletion of the rgg gene in SS2 increased its adhesion to Hep-2 cells and hemolytic activity in vitro. Significantly, inactivation of the rgg gene attenuated SS2 virulence in an experimental piglet infection model. Using DNA microarrays and quantitative reverse transcription-PCR, we found that the Rgg regulator affects the transcriptional profile of 15.87% (n = 345) of all of the annotated chromosomal genes, including those involved in nonglucose carbohydrate metabolism, DNA recombination, protein biosynthesis, bacterial defense mechanisms, and others. It was experimentally verified that the deletion of rgg in SS2 reduced the utilization of nonglucose carbohydrates, such as lactose and maltose. In addition, the rgg gene was found to be associated with changes in the bacterial microscopic phenotype and growth curve. These data suggested that Rgg in SS2 is a global transcriptional regulator that plays an important role in promoting SS2 bacterial survival during pathogen-host interaction.
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Shao Z, Pan X, Li X, Liu W, Han M, Wang C, Wang J, Zheng F, Cao M, Tang J. HtpS, a novel immunogenic cell surface-exposed protein of Streptococcus suis, confers protection in mice. FEMS Microbiol Lett 2010; 314:174-82. [DOI: 10.1111/j.1574-6968.2010.02162.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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49
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Zeng X, Yuan Y, Wei Y, Jiang H, Zheng Y, Guo Z, Tang J, Yang R, Zhou D, Jiang Y. Microarray analysis of temperature-induced transcriptome of Streptococcus suis serotype 2. Vector Borne Zoonotic Dis 2010; 11:215-21. [PMID: 20795872 DOI: 10.1089/vbz.2009.0225] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Streptococcus suis serotype 2 (S. suis S2) is able to cause human infections ranging from superficial wounded skin infections to severe invasive infections such as meningitis and streptococcal toxic shock-like syndrome. During its infection cycle, S. suis S2 must acclimatize itself to temperature shift. Herein, a whole-genome DNA microarray was used to investigate the global transcriptional regulation of an invasive strain of S. suis S2 grown to late-exponential phase at 29°C or 40°C relative to 37°C. The differentially regulated genes that were detected included those encoding virulence factors, antigenic proteins, ATP-binding-cassette transporters, and proteins of unknown functions. Our data provided a global profile of gene transcription induced by temperature alteration and shed light on some unforeseen lines for further pathogenesis investigation.
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Affiliation(s)
- Xiaotao Zeng
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Beijing, China
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50
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Streptococcus suis Infections in Humans: What is the prognosis for Western countries? (Part I). ACTA ACUST UNITED AC 2010. [DOI: 10.1016/j.clinmicnews.2010.05.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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