scholarly journals Streptococcus suis Uptakes Carbohydrate Source from Host Glycoproteins by N-glycans Degradation System for Optimal Survival and Full Virulence during Infection

Pathogens ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 387 ◽  
Author(s):  
Jiale Ma ◽  
Ze Zhang ◽  
Zihao Pan ◽  
Qiankun Bai ◽  
Xiaojun Zhong ◽  
...  
Keyword(s):  
Virulent Strain ◽  
Carbon Sources ◽  
Systemic Infection ◽  
Optimal Growth ◽  
Streptococcus Suis ◽  
Bacterial Survival ◽  
Carbohydrate Source ◽  
Virulent Strains ◽  
High Mannose ◽  
Swine Serum

Infection with the epidemic virulent strain of Streptococcus suis serotype 2 (SS2) can cause septicemia in swine and humans, leading to pneumonia, meningitis and even cytokine storm of Streptococcal toxic shock-like syndrome. Despite some progress concerning the contribution of bacterial adhesion, biofilm, toxicity and stress response to the SS2 systemic infection, the precise mechanism underlying bacterial survival and growth within the host bloodstream remains elusive. Here, we reported the SS2 virulent strains with a more than 20 kb endoSS-related insertion region that showed significantly higher proliferative ability in swine serum than low-virulent strains. Further study identified a complete N-glycans degradation system encoded within this insertion region, and found that both GH92 and EndoSS contribute to bacterial virulence, but that only DndoSS was required for optimal growth of SS2 in host serum. The supplement of hydrolyzed high-mannose-containing glycoprotein by GH92 and EndoSS could completely restore the growth deficiency of endoSS deletion mutant in swine serum. EndoSS only hydrolyzed a part of the model glycoprotein RNase B with high-mannose N-linked glycoforms into a low molecular weight form, and the solo activity of GH92 could not show any changes comparing with the blank control in SDS-PAGE gel. However, complete hydrolyzation was observed under the co-incubation of EndoSS and GH92, suggesting GH92 may degrade the high-mannose arms of N-glycans to generate a substrate for EndoSS. In summary, these findings provide compelling evidences that EndoSS-related N-glycans degradation system may enable SS2 to adapt to host serum-specific availability of carbon sources from glycoforms, and be required for optimal colonization and full virulence during systemic infection.

Evaluation of the growth and sporulation of different entomopathogenic fungi in different liquid and solid media at varied concentrations

2017 ◽  
Vol 6 (8) ◽  
pp. 5459
Author(s):  
Chandra Teja K. ◽  
Rahman S. J.
Keyword(s):  
Entomopathogenic Fungi ◽  
Large Scale ◽  
Insect Pests ◽  
Culture Media ◽  
Virulent Strain ◽  
Carbon Sources ◽  
Nitrogen Sources ◽  
Maximum Growth ◽  
Nutritional Requirements ◽  
Virulent Strains

Entomopathogenic fungi like Beauveria bassiana, Metarhizium anisopliae and Lecanicillium lecanii are used in biological control of agricultural insect pests. Their specific mode of action makes them an effective alternative to the chemical Insecticides. Virulent strains of Entomopathogenic fungi are effectively formulated and used as bio-insecticides world-wide. Amenable and economical multiplication of a virulent strain in a large scale is important for them to be useful in the field. Culture media plays a major role in the large-scale multiplication of virulent strains of Entomopathogens. Different substrates and media components are being used for this purpose. Yet, each strain differs in its nutritional requirements for the maximum growth and hence it is necessary to standardize the right components and their optimum concentrations in the culture media for a given strain of Entomopathogen. In the current study, three different nitrogen sources and two different carbon sources were tried to standardize the mass multiplication media for seven test isolates of Entomopathogenic fungi. A study was also conducted to determine the ideal grain media for the optimum conidial yields of the test isolates. Yeast extract was found to be the best Nitrogen source for the isolates. The isolates tested, differed in their nutritional requirements and showed variation in the best nitrogen and carbon sources necessary for their growth. Variation was also found in the optimum concentration of both the ingredients for the growth and sporulation of the isolates. In the solid-state fermentation study, rice was found to be the best grain for the growth of most of the fungi followed by barley. The significance of such a study in the development of an effective Myco-insecticide is vital and can be successfully employed in agriculture is discussed.

scholarly journals Identification of an Inducible Bacteriophage in a Virulent Strain of Streptococcus suis Serotype 2

2003 ◽  
Vol 71 (10) ◽  
pp. 6104-6108 ◽  
Author(s):  
J. Harel ◽  
G. Martinez ◽  
A. Nassar ◽  
H. Dezfulian ◽  
S. J. Labrie ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Virulent Strain ◽  
Streptococcus Suis ◽  
Swine Industry ◽  
Subtraction Hybridization ◽  
Gram Positive Bacteria ◽  
Virulence Markers ◽  
Virulent Strains ◽  
Phage Dna ◽  
Suis Serotype

ABSTRACT Streptococcus suis infection is considered to be a major problem in the swine industry worldwide. Most virulent Canadian isolates of S. suis serotype 2 do not produce the known virulence markers for this pathogen. PCR-based subtraction hybridization was adapted to isolate unique DNA sequences which were specific to virulent strains of S. suis isolated in Canada. Analysis of some subtracted DNA clones revealed significant homology with bacteriophages of gram-positive bacteria. An inducible phage (named Ss1) was observed in S. suis following the incubation of the virulent strain 89-999 with mitomycin C. Phage Ss1 has a long noncontractile tail and a small isometric nucleocapsid and is a member of the Siphoviridae family. Ss1 phage DNA appears to be present in most Canadian S. suis strains tested in this study, which were isolated from diseased pigs or had proven virulence in mouse or pig models. To our knowledge, this is the first report of the isolation of a phage in S. suis.

scholarly journals Staphylococcus aureusUses the GraXRS Regulatory System To Sense and Adapt to the Acidified Phagolysosome in Macrophages

mBio ◽  
2018 ◽  
Vol 9 (4) ◽  
Author(s):  
Ronald S. Flannagan ◽  
Robert C. Kuiack ◽  
Martin J. McGavin ◽  
David E. Heinrichs
Keyword(s):  
Antimicrobial Properties ◽  
Regulatory System ◽  
Systemic Infection ◽  
Optimal Growth ◽  
Acute Stage ◽  
The Body ◽  
Sensor Kinase ◽  
Acidic Ph ◽  
Bacterial Survival ◽  
Content Type

ABSTRACTMacrophages are critical to innate immunity due to their ability to phagocytose bacteria. The macrophage phagolysosome is a highly acidic organelle with potent antimicrobial properties, yet remarkably, ingestedStaphylococcus aureusreplicates within this niche. Herein we demonstrate thatS. aureusrequires the GraXRS regulatory system for growth within this niche, while the SaeRS and AgrAC two-component regulatory systems and the α-phenol soluble modulins are dispensable. Importantly, we find that it is exposure to acidic pH that is required for optimal growth ofS. aureusinside fully acidified macrophage phagolysosomes. Exposure ofS. aureusto acidic pH evokes GraS signaling, which in turn elicits an adaptive response that endows the bacteria with increased resistance to antimicrobial effectors, such as antimicrobial peptides, encountered inside macrophage phagolysosomes. Notably, pH-dependent induction of antimicrobial peptide resistance inS. aureusrequires the GraS sensor kinase. GraS and MprF, a member of the GraS regulon, play an important role for bacterial survival in the acute stages of systemic infection, where in murine models of infection,S. aureusresides within liver-resident Kupffer cells. We conclude that GraXRS represents a vital regulatory system that functions to allowS. aureusto evade killing, prior to commencement of replication, within host antibacterial immune cells.IMPORTANCES. aureuscan infect any site of the body, including the microbicidal phagolysosome of the macrophage. The ability ofS. aureusto infect diverse niches necessitates that the bacteria be highly adaptable. Here we show thatS. aureusresponds to phagolysosome acidification to evoke changes in gene expression that enable the bacteria to resist phagolysosomal killing and to promote replication. Toxin production is dispensable for this response; however, the bacteria require the sensor kinase GraS, which transduces signals in response to acidic pH. GraS is necessary for phagolysosomal replication and survival ofS. aureusin the acute stage of systemic infection. Disruption of thisS. aureusadaptation would renderS. aureussusceptible to phagocyte restriction.

scholarly journals Genome analysis provides insight into hyper-virulence of Streptococcus suis LSM178, a human strain with a novel sequence type 1005

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yong Hu ◽  
Shiming Fu ◽  
Geng Zou ◽  
Anusak Kerdsin ◽  
Xiabing Chen ◽  
...  
Keyword(s):  
Virulent Strain ◽  
Streptococcus Suis ◽  
Sequence Type ◽  
Type I ◽  
Adaptive Potential ◽  
The Public ◽  
Virulence Regulation ◽  
Virulent Strains ◽  
Highly Virulent ◽  
Insight Into

AbstractStreptococcus suis has been well-recognized as a zoonotic pathogen worldwide, and the diversity and unpredictable adaptive potential of sporadic human strains represent a great risk to the public health. In this study, S. suis LSM178, isolated from a patient in contact with pigs and raw pork, was assessed as a hyper-virulent strain and interpreted for the virulence based on its genetic information. The strain was more invasive for Caco-2 cells than two other S. suis strains, SC19 and P1/7. Sequence analysis designated LSM178 with serotype 2 and a novel sequence type 1005. Phylogenetic analysis showed that LSM178 clustered with highly virulent strains including all human strains and epidemic strains. Compared with other strains, these S. suis have the most and the same virulent factors and a type I-89 K pathogenicity island. Further, groups of genes were identified to distinguish these highly virulent strains from other generally virulent strains, emphasizing the key roles of genes modeling transcription, cell barrier, replication, recombination and repair on virulence regulation. Additionally, LSM178 contains a novel prophage conducive potentially to pathogenicity.

scholarly journals Influence of Different Carbohydrates on Flavonoid Accumulation in Hairy Root Cultures of Scutellaria baicalensis

2016 ◽  
Vol 11 (6) ◽  
pp. 1934578X1601100 ◽  
Author(s):  
Chang Ha Park ◽  
Young Seon Kim ◽  
Xiaohua Li ◽  
Haeng Hoon Kim ◽  
Mariadhas Valan Arasu ◽  
...  
Keyword(s):  
Carbon Source ◽  
Hairy Root ◽  
Carbon Sources ◽  
Optimal Growth ◽  
Growth Conditions ◽  
Scutellaria Baicalensis ◽  
Hairy Root Cultures ◽  
Root Cultures ◽  
Carbohydrate Source ◽  
Half Strength

Carbohydrate sources play important roles in energy and growth of plants. Therefore, in this study, we investigated the optimal carbohydrate source in hairy root cultures (HRCs) of Scutellaria baicalensis infected with Agrobacterium rhizogenes strain R1000. The hairy roots were cultured in half-strength B5 liquid medium supplemented with seven different carbohydrates sources (sucrose, fructose, glucose, galactose, sorbitol, mannitol and maltose), each at a concentration of 100 mM, in order to identify the best carbon sources for the production of major flavones, such as wogonin, baicalin and baicalein. Sucrose, galactose and fructose markedly influenced the production of major flavones and were therefore chosen for subsequent experiments. HRC growth and flavone accumulation were examined following culture with 30, 100 and 150 mM sucrose, galactose and fructose, respectively. From these data, 150 mM sucrose was found to be the optimal carbon source for the enhancement of baicalein production and growth of S. baicalensis HRCs. Fructose caused the greatest increase in baicalin accumulation. Additionally, galactose was the optimal carbon source for wogonin production. These results provide important insights into the optimal growth conditions, particularly the appropriate carbohydrate source, for S. baicalensis.

scholarly journals Salmonella Typhimurium reprograms macrophage metabolism via T3SS effector SopE2 to promote intracellular replication and virulence

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Lingyan Jiang ◽  
Peisheng Wang ◽  
Xiaorui Song ◽  
Huan Zhang ◽  
Shuangshuang Ma ◽  
...  
Keyword(s):  
Carbon Sources ◽  
Systemic Infection ◽  
Pathogenicity Island ◽  
Intracellular Replication ◽  
Glucose Levels ◽  
T3ss Effector ◽  
Glycolytic Intermediates ◽  
Bacterial Uptake ◽  
Lactate Levels ◽  
Host Metabolism

AbstractSalmonella Typhimurium establishes systemic infection by replicating in host macrophages. Here we show that macrophages infected with S. Typhimurium exhibit upregulated glycolysis and decreased serine synthesis, leading to accumulation of glycolytic intermediates. The effects on serine synthesis are mediated by bacterial protein SopE2, a type III secretion system (T3SS) effector encoded in pathogenicity island SPI-1. The changes in host metabolism promote intracellular replication of S. Typhimurium via two mechanisms: decreased glucose levels lead to upregulated bacterial uptake of 2- and 3-phosphoglycerate and phosphoenolpyruvate (carbon sources), while increased pyruvate and lactate levels induce upregulation of another pathogenicity island, SPI-2, known to encode virulence factors. Pharmacological or genetic inhibition of host glycolysis, activation of host serine synthesis, or deletion of either the bacterial transport or signal sensor systems for those host glycolytic intermediates impairs S. Typhimurium replication or virulence.

scholarly journals Differential Bacterial Survival, Replication, and Apoptosis-Inducing Ability of Salmonella Serovars within Human and Murine Macrophages

2000 ◽  
Vol 68 (3) ◽  
pp. 1005-1013 ◽  
Author(s):  
William R. Schwan ◽  
Xiao-Zhe Huang ◽  
Lan Hu ◽  
Dennis J. Kopecko
Keyword(s):  
Typhoid Fever ◽  
Systemic Infection ◽  
Peritoneal Macrophages ◽  
Human Macrophage ◽  
U937 Cells ◽  
Bacterial Survival ◽  
Human Macrophages ◽  
Macrophage Cells ◽  
Serovar Typhimurium ◽  
Murine Peritoneal Macrophages

ABSTRACT Salmonella serovars are associated with human diseases that range from mild gastroenteritis to host-disseminated enteric fever. Human infections by Salmonella enterica serovar Typhi can lead to typhoid fever, but this serovar does not typically cause disease in mice or other animals. In contrast, S. enterica serovar Typhimurium and S. entericaserovar Enteritidis, which are usually linked to localized gastroenteritis in humans and some animal species, elicit a systemic infection in mice. To better understand these observations, multiple strains of each of several chosen serovars of Salmonellawere tested for the ability in the nonopsonized state to enter, survive, and replicate within human macrophage cells (U937 and elutriated primary cells) compared with murine macrophage cells (J774A.1 and primary peritoneal cells); in addition, death of the infected macrophages was monitored. The serovar Typhimurium strains all demonstrated enhanced survival within J774A.1 cells and murine peritoneal macrophages, compared with the significant, almost 100-fold declines in viable counts noted for serovar Typhi strains. Viable counts for serovar Enteritidis either matched the level of serovar Typhi (J774A.1 macrophages) or were comparable to counts for serovar Typhimurium (murine peritoneal macrophages). Apoptosis was significantly higher in J774A.1 cells infected with serovar Typhimurium strain LT2 compared to serovar Typhi strain Ty2. On the other hand, serovar Typhi survived at a level up to 100-fold higher in elutriated human macrophages and 2- to 3-fold higher in U937 cells compared to the serovar Typhimurium and Enteritidis strains tested. Despite the differential multiplication of serovar Typhi during infection of U937 cells, serovar Typhi caused significantly less apoptosis than infections with serovar Typhimurium. These observations indicate variability in intramacrophage survival and host cytotoxicity among the various serovars and are the first to show differences in the apoptotic response of distinctSalmonella serovars residing in human macrophage cells. These studies suggest that nonopsonized serovar Typhimurium enters, multiplies within, and causes considerable, acute death of macrophages, leading to a highly virulent infection in mice (resulting in death within 14 days). In striking contrast, nonopsonized serovar Typhi survives silently and chronically within human macrophages, causing little cell death, which allows for intrahost dissemination and typhoid fever (low host mortality). The type of disease associated with any particular serovar of Salmonellais linked to the ability of that serovar both to persist within and to elicit damage in a specific host's macrophage cells.

scholarly journals Fermentative Capacity of Three Strains of Lactobacillus Using Different Sources of Carbohydrates: In Vitro Evaluation of Synbiotic Effects, Resistance and Tolerance to Bile and Gastric Juices

2013 ◽  
Vol 2 (1) ◽  
pp. 158 ◽  
Author(s):  
Dolar Pak ◽  
Arunachalam Muthaiyan ◽  
Robert S. Story ◽  
Corliss A. O'Bryan ◽  
Sun-Ok Lee ◽  
...  
Keyword(s):  
Growth Rate ◽  
Carbon Sources ◽  
Basal Medium ◽  
Lactobacillus Bulgaricus ◽  
Carbohydrate Source ◽  
Fermentative Capacity ◽  
Colony Forming Units ◽  
Test Organisms ◽  
Different Sources

<p>A fermentation study of three probiotic <em>Lactobacillus</em> strains was conducted on individual carbohydrates including glucose (GLU) high methoxy pectin (HMP), sugar beet pectin (SBP), fructooligosaccharide (FOS), galactooligosaccharide (GOS), and inulin agave (IA) as the sole carbon sources. It was observed that <em>Lactobacillus bulgaricus </em>(LB), <em>Lactobacillus casei</em> (LC) and <em>Lactobacillus delbruckii</em> (LD) achieved the highest growth rates when they were grown in the presence of GLU, FOS, and IA, but LB had a slower growth rate in these substrates compared to LC and LD. Only LC had a statistically significantly higher growth rate in GOS than in the basal medium which contained no carbohydrate source. Exposure to bile caused a significant reduction of log colony forming units/ml of all 3 strains, with LD grown in HMP exhibiting the highest survival followed by LC and LD grown in GLU, and LD grown on IA. Although HMP was not fermented by the test organisms, results indicate that HMP may in fact help certain probiotic bacteria to survive exposure to bile. Exposure to simulated gastric juices indicated that the studied <em>Lactobacilli</em> are tolerant to simulated gastric juice.</p>

scholarly journals Draft Genome Sequence of Streptococcus suis S10, a Virulent Strain Used in Experimental Pig Infections

2019 ◽  
Vol 8 (23) ◽  
Author(s):  
Rogier A. Gaiser ◽  
Aldert L. Zomer ◽  
Jerry M. Wells ◽  
Peter van Baarlen
Keyword(s):  
Infectious Diseases ◽  
Genome Sequence ◽  
Virulent Strain ◽  
Draft Genome ◽  
Streptococcus Suis ◽  
Draft Genome Sequence ◽  
Whole Genome Sequence ◽  
Whole Genome ◽  
Content Type ◽  
Highly Virulent

Here, we report the draft whole-genome sequence of Streptococcus suis strain S10, isolated from the tonsils of a healthy pig. S. suis S10 belongs to the highly virulent serotype 2, which includes isolates that cause infectious diseases, including meningitis, in pigs and human.

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