The Effect of Culture Condition on Type 5 Capsular Polysaccharide Production of Staphylococcus aureus from Diary Cattle

[Objective] The effect of different culture conditions on type 5 capsular polysaccharide production of Staphylococcus aureus from diary cattle was studied to provide simple way for CP production and preparation and laid foundation for carrying out new polysaccharide vaccine research. [Method] Staph-ylococcus aureus was isolated from milk sample of sick dairy cattle and capsular polysaccharide serotypes were identified. Type 5 capsular polysaccharide was cultured on BHI,solid columbia and mod110 culture media. Glucose and lactose were taken as carbon sources for every culture media in solid and liquid state. Therefore 9 different culture conditions were taken to study the effect of culture conditions on capsular polysaccharide production. [Result] Different culture conditions indicated that compared with columbia culture media, BHI culture media could decline capsular polysaccharide production and mod110 culture media could increase capsular polysaccharide production. While for same culture media, solid culture media was better for capsular polysaccharide production,meanwhile,taken lactose as carbon source could increase capsular polysaccharide production.

Capsular polysaccarides of probiotics and their immunomodulatory roles

Studies have determined the immunomodulatory activities of cell-surface polysaccharides of lactic acid bacteria(LAB)and Bacteroides;however,the mechanisms,synthesis,regulation,structure,and functional links have not been systematically discussed.We first introduce the structure of the capsular poly saccharides(CPS s)of commonly studied probiotics and Bacteroides.Wzx-Wzy dependent and ATP-binding cassette(ABC)transporter-dependent pathways are the two main biosynthesis and secretion of CPS pathways.The genes known to be associated with these two pathways are mainly those associated with priming glycosyltransferase(pGT);a variable number of genes encoding for different glycosyl transferases(GTs);Wzx/Wzy-encoding enzymes related to flippases and polymerases;and ABC-transporter genes.In addition,the effects of CPSs on host immunity as well as their related underlying mechanisms are described.Surface polysaccharides on probiotics can serve as a mask to aid in their escape from attacks from the host’s immune system.In turn,they also exhibit immunomodulatory activities,such as strengthening the functions of macrophages,promoting the maturation of antigen-presenting cells,and inducing regulatory T cells.All of these effects of cell-surface polysaccharides exhibit their significant protective properties in immunocompromised diseases,such as colitis,arthritis,and dermatitis.Finally,we focused on their structure and functional links.

Genetic Characteristics of Lipooligosaccharide and Capsular Polysaccharide of Campylobacter jejuni from Different Sources in China

Objective To determine the distribution of two important virulence factors[lipooligosaccharide(LOS)and capsular polysaccharide(CPS)]in Campylobacter jejuni(C.jejuni)isolated from different sources in China and to develop a rapid screening method for Guillain–Barrésyndrome(GBS)-associated strains.Methods Whole-genome sequencing was carried out for 494 C.jejuni strains.The Ortho MCL software was used to define the LOS/CPS gene clusters.CPS genotyping was performed with serotype-specific sequence alignment using the BLAST software.Real-time Polymerase chain reaction(PCR)was developed with the unique sequences of specific CPS types.Results Nine novel and 29 previously confirmed LOS classes were identified.LOS classes A,B,and C were the most common(48.2%,238/494)among the 494 strains.Twenty-six capsular types were identified in 448 strains.HS2,HS4c,HS5/31,HS19,and HS8/17 were the most frequent CPS genotypes(58.7%,263/448).Strains of 17 CPS genotypes(strain number>5)had one or two prevalent LOS classes(P<0.05).Multiplex real-time PCR for rapid identification of HS2,HS19,and HS41 was developed and validated with strains of known serotypes.Conclusion Our results describe the genetic characteristics of the important virulence factors in C.jejuni strains in China.The multiplex real-time PCR developed in this study will facilitate enhanced surveillance of GBS-associated strains in China.

Synthesis of a conjugable hexasaccharide corresponding to the capsular polysaccharide of Campylobacter jejuni strain BH0142

The first assembly of a conjugation-ready hexasaccharide from the capsular glycan of C.jejuni.strain BH0142 has been accomplished.The synthesis features the efficient preparation of 6-deoxy-D-idoheptopyranosyl fluoride donors proceeding from allylα-D-C-glucopyranoside by a C1-to-C5 switch strategy with radical dehydroxymethylative fluorination as a key step,stereocontrolled construction of 1,2-trans-α-D-ido-heptopyranosidic bonds and of 1,2-cis-α-D-galactopyranosidic linkages.The obtained target oligosaccharide sets a solid foundation for making structurally-defined multivalent glycoconjugate vaccine candidates against C.jejuni.infections.

Determination of ribose and phosphorus contents in Haemophilus influenzae type b capsular polysaccharide by a quantitative NMR method using a single internal standard

The ribose and phosphorus contents in Haemophilus influenzae type b(Hib)capsular polysaccharide(CPS)are two important chemical indexes for the development and quality control of Hib conjugate vaccine.A quantitative ^(1)H-and ^(31)P-NMR method using a single internal standard was developed for simultaneous determination of ribose and phosphorus contents in Hib CPS.Hexamethylphosphoramide(HMPA)was successfully utilized as an internal standard in quantitative ^(1)H-NMR method for ribose content determination.The ribose and phosphorus contents were found to be affected by the concentration of polysaccharide solution.Thus,15–20 mg·L^(−1) was the optimal concentration range of Hib CPS in D_(2)O solution for determination of ribose and phosphorus contents by this method.The ribose and phosphorus contents obtained by the quantitative NMR were consistent with those obtained by traditional chemical methods.In conclusion,this quantitative ^(1)H-and ^(31)P-NMR method using a single internal standard shows good specificity,accuracy and precision,providing a valuable approach for the quality control of Hib glycoconjugate vaccines.

Sequential One-Pot Three-Enzyme Synthesis of the Tetrasaccharide Repeating Unit of Group B Streptococcus Serotype Ⅷ Capsular Polysaccharide

The biochemical property and functional identification of three recombinant glycosyltransferases,includingβ-1,4-rhamnosyltransferase(Cps8R),β-1,4-galactosyltransferase(Cps8) and α-2,3-sialyltransferase(Cps8K)involved in the biosynthesis of the tetrasaccharide repeating unit of serotypeⅧcapsular polysaccharide(CPS)of Group B Streptococci(GBS),were systematically investigated.Subsequently,these recombinant enzymes were employed for one-pot three-enzyme efficient synthesis of the tetrasaccharide repeating unit of GBS serotypeⅧCPS using the chemically synthesized Glca-PP-(CH2)ir-OPh as the starting substrate in a satisfying yieldof 87%.