scholarly journals Role of Maturation of Lipoproteins in the Pathogenesis of the Infection Caused by Streptococcus suis Serotype 2

2021 ◽  
Vol 9 (11) ◽  
pp. 2386
Author(s):  
Servane Payen ◽  
David Roy ◽  
Anaïs Boa ◽  
Masatoshi Okura ◽  
Jean-Philippe Auger ◽  
...  
Keyword(s):  
Bacterial Pathogen ◽  
Streptococcus Suis ◽  
Signal Peptidase ◽  
Phagocytic Cells ◽  
Suis Serotype ◽  
Highly Virulent ◽  
Streptococcus Suis Serotype 2

Streptococcus suis serotype 2 is an important porcine bacterial pathogen associated with multiple pathologies in piglets. Bacterial lipoproteins (LPPs) have been described as playing important roles in the pathogenesis of the infection of other Gram-positive bacteria as adhesins, pro-inflammatory cell activators and/or virulence factors. In the current study, we aimed to evaluate the role of the prolipoprotein diacylglyceryl transferase (Lgt) and lipoprotein signal peptidase (Lsp) enzymes, which are responsible for LPP maturation, on the pathogenesis of the infection caused by two different sequence types (STs) of S. suis serotype 2 strains (virulent ST1 and highly virulent ST7). Through the use of isogenic Δlgt, Δlsp and double Δlgt/Δlsp mutants, it was shown that lack of these enzymes did not influence S. suis adhesion/invasion to porcine respiratory epithelial cells. However, in the absence of the Lsp and/or Lgt, a significant reduction in the capacity of S. suis to activate phagocytic cells and induce pro-inflammatory mediators (in vitro and in vivo) was observed. In general, results obtained with the double mutant did not differ in comparison to single mutants, indicating lack of an additive effect. Finally, our data suggest that these enzymes play a differential role in virulence, depending on the genetic background of the strain and being more important for the highly virulent ST7 strain.

scholarly journals Recognition of Lipoproteins by Toll-like Receptor 2 and DNA by the AIM2 Inflammasome Is Responsible for Production of Interleukin-1β by Virulent Suilysin-Negative Streptococcus suis Serotype 2

Pathogens ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 147 ◽  
Author(s):  
Agustina Lavagna ◽  
Jean-Philippe Auger ◽  
Stephen E. Giradin ◽  
Nicolas Gisch ◽  
Mariela Segura ◽  
...  
Keyword(s):  
Bacterial Pathogen ◽  
Systemic Infection ◽  
Streptococcus Suis ◽  
Bacterial Burden ◽  
Toll Like Receptor ◽  
Internalization Rate ◽  
Toll Like Receptor 2 ◽  
Suis Serotype ◽  
Streptococcus Suis Serotype 2

Streptococcus suis serotype 2 is an important porcine bacterial pathogen and zoonotic agent causing sudden death, septic shock and meningitis. These pathologies are the consequence of an exacerbated inflammatory response composed of various mediators including interleukin (IL)-1β. Elevated levels of the toxin suilysin (SLY) were demonstrated to play a key role in S. suis-induced IL-1β production. However, 95% of serotype 2 strains isolated from diseased pigs in North America, many of which are virulent, do not produce SLY. In this study, we demonstrated that SLY-negative S. suis induces elevated levels of IL-1β in systemic organs, with dendritic cells contributing to this production. SLY-negative S. suis-induced IL-1β production requires MyD88 and TLR2 following recognition of lipoproteins. However, the higher internalization rate of the SLY-negative strain results in intracellularly located DNA being recognized by the AIM2 inflammasome, which promotes IL-1β production. Finally, the role of IL-1 in host survival during the S. suis systemic infection is beneficial and conserved, regardless of SLY production, via modulation of the inflammation required to control bacterial burden. In conclusion, this study demonstrates that SLY is not required for S. suis-induced IL-1β production.

Lipoprotein signal peptidase of Streptococcus suis serotype 2

Microbiology ◽  
2003 ◽  
Vol 149 (6) ◽  
pp. 1399-1407 ◽  
Author(s):  
Astrid de Greeff ◽  
Andrea Hamilton ◽  
Iain C. Sutcliffe ◽  
Herma Buys ◽  
Loek van Alphen ◽  
...  
Keyword(s):  
Wild Type Strain ◽  
Streptococcus Suis ◽  
Signal Peptidase ◽  
Wild Type ◽  
Knockout Mutant ◽  
E Coli ◽  
Translation Systems ◽  
Suis Serotype

This paper reports the complete coding sequence for a proliprotein signal peptidase (SP-ase) of Streptococcus suis, Lsp. This is believed to be the first SP-ase described for S. suis. SP-ase II is involved in the removal of the signal peptide from glyceride-modified prolipoproteins. By using in vitro transcription/translation systems, it was shown that the lsp gene was transcribed in vitro. Functionality of Lsp in Escherichia coli was demonstrated by using an in vitro globomycin resistance assay, to show that expression of Lsp in E. coli increased the globomycin resistance. An isogenic mutant of S. suis serotype 2 unable to produce Lsp was constructed and shown to process lipoproteins incorrectly, including an S. suis homologue of the pneumococcal PsaA lipoprotein. Five piglets were inoculated with a mixture of both strains in an experimental infection, to determine the virulence of the mutant strain relative to that of the wild-type strain in a competitive challenge experiment. The data showed that both strains were equally virulent, indicating that the knockout mutant of lsp is not attenuated in vivo.

scholarly journals Streptococcus suis Serotype 2 Capsule In Vivo

2016 ◽  
Vol 22 (10) ◽  
pp. 1793-1796 ◽  
Author(s):  
Jean-Philippe Auger ◽  
Nattakan Meekhanon ◽  
Masatoshi Okura ◽  
Makoto Osaki ◽  
Marcelo Gottschalk ◽  
...  
Keyword(s):  
Streptococcus Suis ◽  
Suis Serotype ◽  
Streptococcus Suis Serotype 2

scholarly journals In Vitro and In Vivo Interactions of Haemophilusducreyi with Host Phagocytes

2002 ◽  
Vol 70 (2) ◽  
pp. 899-908 ◽  
Author(s):  
Hinda J. Ahmed ◽  
Catharina Johansson ◽  
Liselott A. Svensson ◽  
Karin Ahlman ◽  
Margareta Verdrengh ◽  
...  
Keyword(s):  
Bacterial Resistance ◽  
Experimental Period ◽  
Skin Lesions ◽  
Phagocytic Cells ◽  
Innate Defense ◽  
Gentamicin Treatment ◽  
Monocyte Cell

ABSTRACT We investigated the phagocytosis of Haemophilus ducreyi both in vitro and in vivo. Human granulocyte and monocyte phagocytosis of opsonized and nonopsonized, fluorescence-labeled H. ducreyi was assessed by flow cytometry. Both Escherichia coli and noncapsulated H. influenzae were included as controls. The maximal percentage of granulocytes taken up by H. ducreyi was 35% after 90 min. In contrast, 95% of H. influenzae bacteria were phagocytosed by granulocytes after 30 min. These results indicated that H. ducreyi phagocytosis was slow and inefficient. Bacterial opsonization by using specific antibodies increased the percentage of granulocytes phagocytosing H. ducreyi from 24 to 49%. The nonphagocytosed bacteria were completely resistant to phagocytosis even when reexposed to granulocytes, indicating that the H. ducreyi culture comprised a mixture of phenotypes. The intracellular survival of H. ducreyi in granulocytes, in monocytes/macrophages, and in a monocyte cell line (THP-1) was quantified after application of gentamicin treatment to kill extracellular bacteria. H. ducreyi survival within phagocytes was poor; approximately 11 and <0.1% of the added bacteria survived intracellularly after 2 and 20 h of incubation, respectively, while no intracellular H. influenzae bacteria were recovered after 2 h of incubation with phagocytes. The role of phagocytes in the development of skin lesions due to H. ducreyi was also studied in vivo. Mice that were depleted of granulocytes and/or monocytes and SCID mice, which lacked T and B cells, were injected intradermally with approximately 106 CFU of H. ducreyi. Within 4 days of inoculation, the granulocyte-depleted mice developed lesions that persisted throughout the experimental period. This result reinforces the importance of granulocytes in the early innate defense against H. ducreyi infection. In conclusion, H. ducreyi is insufficiently phagocytosed to achieve complete eradication of the bacteria. Indeed, H. ducreyi has the ability to survive intracellularly for short periods within phagocytic cells in vitro. Since granulocytes play a major role in the innate defense against H. ducreyi infection in vivo, bacterial resistance to phagocytosis probably plays a crucial role in the pathogenesis of chancroid.

Differential role of MyD88 signaling in Streptococcus suis serotype 2-induced systemic and central nervous system diseases

2019 ◽  
Vol 31 (11) ◽  
pp. 697-714 ◽  
Author(s):  
Jean-Philippe Auger ◽  
Marie-Odile Benoit-Biancamano ◽  
Christian Bédard ◽  
Mariela Segura ◽  
Marcelo Gottschalk
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Streptococcus Suis ◽  
Nervous System Diseases ◽  
Central Nervous System Diseases ◽  
Myd88 Signaling ◽  
Suis Serotype ◽  
Streptococcus Suis Serotype 2

MyD88 signaling modulates the outcome of Streptococcus suis infection

scholarly journals In vitro Transcriptome Analysis of Two Chinese Isolates of Streptococcus suis Serotype 2

2014 ◽  
Vol 12 (6) ◽  
pp. 266-275
Author(s):  
Dake Zhang ◽  
Nan Du ◽  
Sufang Ma ◽  
Qingtao Hu ◽  
Guangwen Lu ◽  
...  
Keyword(s):  
Transcriptome Analysis ◽  
Streptococcus Suis ◽  
Suis Serotype ◽  
Streptococcus Suis Serotype 2
Sign in / Sign up

Export Citation Format

Share Document