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Shousun C Szu - One of the best experts on this subject based on the ideXlab platform.
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synthesis chArActerizAtion And immunologicAl properties in mice of conjugAtes composed of detoxified lipopolysAcchAride of SAlmonellA PArAtyphi A bound to tetAnus toxoid with emphAsis on the role of o Acetyls
Infection and Immunity, 1996Co-Authors: E Konadu, Joseph Shiloach, Dolores A Bryla, John B Robbins, Shousun C SzuAbstract:SAlmonellA PArAtyphi A, the second most common cAuse of enteric fever in SoutheAst AsiA, is A hAbitAnt of And A pAthogen for humAns only. LipopolysAcchArides (LPS) Are both essentiAl virulence fActors And protective Antigens for systemic infections cAused by groups A, B, C, And D nontyphoidAl SAlmonellAe. The O-specific polysAcchAride of S. PArAtyphi A is composed of A trisAcchAride, -->2-AlphA-D)-MAnp-(1-->4)-AlphA-L-RhAp-(1-->3)-AlphA-D-GAlp -(1-->, with A brAnch of D-pArAtose from the C-3 of AlphA-D-mAnnose, And the C-3 of betA-L-rhAmnose is pArtiAlly O AcetylAted (C. G. Hellerqvist, B. Lindberg, K. SAmuelsson, And A. A. Lindberg, ActA Chem. ScAnd. 25:955-961, 1971). On the bAsis of dAtA from our investigAtionAl vAccines for enteric bActeriAl pAthogens, including group B SAlmonellAe (D. C. WAtson, J. B. Robbins, And S. C. Szu, Infect. Immun. 60:4679-4686, 1992), conjugAtes composed of the detoxified LPS of S. PArAtyphi A bound to tetAnus toxoid (TT) were prepAred by severAl schemes. LPS wAs detoxified with Acetic Acid or with hydrAzine; the lAtter removed O Acetyls from the O-specific polysAcchAride. The detoxified polysAcchArides were ActivAted with cyAnogen bromide (CNBr) or with 1-cyAno-4-dimethylAminopyridinium tetrAtfluoroborAte (CDAP) And bound to TT with or without A spAcer. Solutions of 2.5 microgrAm of sAcchAride, Alone or As A conjugAte, were injected subcutAneously into young mice, And LPS And TT Antibodies were meAsured by enzyme-linked immunosorbent AssAying. A conjugAte synthesized with higher-moleculAr-weight O-SP elicited the highest Anti-LPS levels. Only conjugAtes with O Acetyls elicited serum immunoglobulin G Anti-LPS with bActericidAl Activity. There were no stAtisticAlly significAnt differences between LPS Antibody levels elicited by conjugAtes synthesized with or without A spAcer. The conjugAte with O-specific polysAcchAride ActivAted by CDAP And bound to TT without A spAcer elicited the highest level of TT Antibodies. ClinicAl evAluAtion (if S. PArAtyphi A conjugAtes is plAnned.
Anu Kantele - One of the best experts on this subject based on the ideXlab platform.
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cross reActive gut directed immune response AgAinst SAlmonellA entericA serovAr PArAtyphi A And b in typhoid fever And After orAl ty21A typhoid vAccinAtion
Vaccine, 2012Co-Authors: Sari H Pakkanen, Jussi M Kantele, Anu KanteleAbstract:AbstrAct BAckground There Are no vAccines AgAinst pArAtyphoid fever in clinicAl use. The diseAse hAs become more wide-spreAd And there is A growing problem of Antibiotic resistAnce Among the strAins. Previous reports suggest thAt the orAl live SAlmonellA Typhi Ty21A-vAccine confers protection AgAinst pArAtyphoid B fever. DAtA on efficAcy AgAinst pArAtyphoid A fever Are somewhAt contentious. The present study investigAted the immunologicAl bAsis for such efficAcy reports At A single-cell level: plAsmAblAsts (identified As Antibody-secreting cells, ASC) were studied for secretion of Antibodies cross-reActive with SAlmonellA PArAtyphi in the circulAtion of pAtients with enteric fever And of volunteers vAccinAted with Ty21A. MAteriAls And methods Thirty volunteers immunized with Ty21A And five pAtients with enteric fever were investigAted for SAlmonellA Typhi And SAlmonellA PArAtyphi A/B/C-specific circulAting plAsmAblAsts. PBMC were sorted by their expression of homing receptors (HR) for the intestine (α4β7), peripherAl lymph node ( l -selectin) And skin (CLA) And typhoid- And pArAtyphoid-specific plAsmAblAsts were enumerAted with ELISPOT. Results Before vAccinAtion, no cross-reActive ASC were found in the volunteers. In Addition to the SAlmonellA Typhi-specific response, A significAnt cross-reActive immune response wAs mounted AgAinst SAlmonellA PArAtyphi A And B both in the pAtients And the vAccinees. The mAgnitude of the response increAsed in the order SAlmonellA PArAtyphi A (mediAn 30 ASC/10 6 PBMC) → SAlmonellA PArAtyphi B (mediAn 81) → SAlmonellA Typhi (mediAn 301) in the vAccinees. Both in pAtients And in vAccinees, the homing receptor (HR) selection fAvored homing to the gut, indicAting A humorAl intestinAl immune response. Conclusions These immunologicAl dAtA provide evidence consistent with previous reports describing certAin levels of cross-protective efficAcy of Ty21A AgAinst pArAtyphoid fever. Controlled studies Are needed to evAluAte cross-protective efficAcy. In the current situAtion where pArAtyphoid fever is emerging And no vAccines Are AvAilAble, Any level of cross-protective cApAcity is vAluAble.
Debashis Dhara - One of the best experts on this subject based on the ideXlab platform.
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Syntheses of SAlmonellA PArAtyphi A AssociAted oligosAcchAride Antigens And development towArds Anti‐pArAtyphoid fever vAccines
Chemistry – A European Journal, 2020Co-Authors: Debashis Dhara, Scott M. Baliban, Chang-xin Huo, Zahra Rashidijahanabad, Khandra T. Sears, Setare Tahmasebi Nick, Anup Kumar Misra, Sharon M. Tennant, Xuefei HuangAbstract:With the emergence of multidrug resistAnt SAlmonellA strAins, the development of Anti- SAlmonellA vAccines is An importAnt tAsk. Currently there Are no Approved vAccines AgAinst SAlmonellA PArAtyphi A, the leAding cAuse of pArAtyphoid fever. To fill this gAp, oligosAcchArides corresponding to the O -polysAcchAride repeAting units from the surfAce of SAlmonellA PArAtyphi A hAve been synthesized through convergent stereoselective glycosylAtions. The synthetic glycAn Antigen wAs conjugAted with A powerful immunogenic cArrier system, the bActeriophAge Qβ. The resulting construct wAs Able to elicit strong And long-lAsting Anti-glycAn IgG Antibody responses, which were highly selective towArd SAlmonellA PArAtyphi A AssociAted glycAns. The AvAilAbility of well-defined glycAn Antigen enAbled the determinAtion thAt one repeAting unit of the polysAcchAride is sufficient to induce protective Antibodies, And the pArAtose residue And/or the O -Acetyl modificAtions on the bAckbone Are importAnt for recognition by Antibodies elicited by A Qβ-tetrAsAcchAride conjugAte. Immune serA provided excellent protection to mice from lethAl chAllenge with SAlmonellA PArAtyphi A, highlighting the potentiAl of the synthetic glycAn-bAsed vAccine.
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syntheses of SAlmonellA PArAtyphi A AssociAted oligosAcchAride Antigens And development towArds Anti pArAtyphoid fever vAccines
Chemistry: A European Journal, 2020Co-Authors: Debashis Dhara, Scott M. Baliban, Chang-xin Huo, Zahra Rashidijahanabad, Khandra T. Sears, Setare Tahmasebi Nick, Anup Kumar Misra, Sharon M. Tennant, Xuefei HuangAbstract:With the emergence of multidrug resistAnt SAlmonellA strAins, the development of Anti-SAlmonellA vAccines is An importAnt tAsk. Currently there Are no Approved vAccines AgAinst SAlmonellA PArAtyphi A, the leAding cAuse of pArAtyphoid fever. To fill this gAp, oligosAcchArides corresponding to the O-polysAcchAride repeAting units from the surfAce of SAlmonellA PArAtyphi A hAve been synthesized through convergent stereoselective glycosylAtions. The synthetic glycAn Antigen wAs conjugAted with A powerful immunogenic cArrier system, the bActeriophAge Qβ. The resulting construct wAs Able to elicit strong And long-lAsting Anti-glycAn IgG Antibody responses, which were highly selective towArd SAlmonellA PArAtyphi A AssociAted glycAns. The AvAilAbility of well-defined glycAn Antigen enAbled the determinAtion thAt one repeAting unit of the polysAcchAride is sufficient to induce protective Antibodies, And the pArAtose residue And/or the O-Acetyl modificAtions on the bAckbone Are importAnt for recognition by Antibodies elicited by A Qβ-tetrAsAcchAride conjugAte. Immune serA provided excellent protection to mice from lethAl chAllenge with SAlmonellA PArAtyphi A, highlighting the potentiAl of the synthetic glycAn-bAsed vAccine.
Biao Kan - One of the best experts on this subject based on the ideXlab platform.
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the core proteome And pAn proteome of SAlmonellA PArAtyphi A epidemic strAins
PLOS ONE, 2014Co-Authors: Li Zhang, Haijian Zhou, Bo Pang, Di Xiao, Qian Zhang, Lijuan Zhang, Jianzhong Zhang, Biao KanAbstract:CompArAtive proteomics of the multiple strAins within the sAme species cAn reveAl the genetic vAriAtion And relAtionships Among strAins without the need to Assess the genomic dAtA. SimilAr to compArAtive genomics, core proteome And pAn proteome cAn Also be obtAined within multiple strAins under the sAme culture conditions. In this study we present the core proteome And pAn proteome of four epidemic SAlmonellA PArAtyphi A strAins cultured under lAborAtory culture conditions. The proteomic informAtion wAs obtAined using A Two-dimensionAl gel electrophoresis (2-DE) technique. The expression profiles of these strAins were conservAtive, similAr to the monomorphic genome of S. PArAtyphi A. Few strAin-specific proteins were found in these strAins. Interestingly, non-core proteins were found in similAr cAtegories As core proteins. However, significAnt fluctuAtions in the AbundAnce of some core proteins were Also observed, suggesting thAt there is elAborAte regulAtion of core proteins in the different strAins even when they Are cultured in the sAme environment. Therefore, core proteome And pAn proteome AnAlysis of the multiple strAins cAn demonstrAte the core pAthwAys of metAbolism of the species under specific culture conditions, And further the specific responses And AdAptAtions of the strAins to the growth environment.
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pAn genomic AnAlysis provides insights into the genomic vAriAtion And evolution of SAlmonellA PArAtyphi A
PLOS ONE, 2012Co-Authors: Weili Liang, Chunxia Chen, Yongbing Zhao, Xiaoying Cui, Jingfa Xiao, Biao KanAbstract:SAlmonellA PArAtyphi A (S. PArAtyphi A) is A highly AdApted, humAn-specific pAthogen thAt cAuses pArAtyphoid fever. CAses of pArAtyphoid fever hAve recently been increAsing, And the diseAse is becoming A mAjor public heAlth concern, especiAlly in EAstern And Southern AsiA. To investigAte the genomic vAriAtion And evolution of S. PArAtyphi A, A pAn-genomic AnAlysis wAs performed on five newly sequenced S. PArAtyphi A strAins And two other reference strAins. A whole genome compArison reveAled thAt the seven genomes Are collineAr And thAt their orgAnizAtion is highly conserved. The high rAte of substitutions in pArt of the core genome indicAtes thAt there Are frequent homologous recombinAtion events. BAsed on the chAnges in the pAn-genome size And cluster number (both in the core functionAl genes And core pseudogenes), it cAn be inferred thAt the shArply increAsing number of pseudogene clusters mAy hAve strong correlAtion with the inActivAtion of functionAl genes, And indicAtes thAt the S. PArAtyphi A genome is being degrAded.
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Multilocus sequence typing And pulsed-field gel electrophoresis AnAlysis of SAlmonellA PArAtyphi A isolAtes from 2000 to 2008, ChinA
Zhonghua yu fang yi xue za zhi [Chinese journal of preventive medicine], 2010Co-Authors: Hui Han, Haijian Zhou, Zhigang Cui, Biao KanAbstract:Objective To AnAlyze moleculAr And evolution chArActeristics of SAlmonellA PArAtyphi A isolAtes from 2000 to 2008, ChinA. Methods Using pulsed-field gel electrophoresis (PFGE) method with Spe Ⅰ restriction enzyme, And multilocus sequence typing (MLST) method bAsed on housekeeping genes (AroC, thrA, hisD, purE, sucA, dnAN, hemD, Adk, And purA), the genomic vAriAtions of 118 SAlmonellA PArAtyphi A isolAtes from 10 regions during 2000 to 2008 were AnAlyzed. Results Using PFGE method, 118 SAlmonellA PArAtyphi A isolAtes were clustered into 32 PFGE pAtterns, And 5 pAtterns were predominAnt (5 isolAtes or Above). However,only 2 MLST types were identified for All isolAtes with MLST method. Among All SAlmonellA PArAtyphi A isolAtes, the sequences of housekeeping genes were highly conservAtive And showed A high degree of cloning. Conclusion For Chinese epidemic SAlmonellA PArAtyphi A isolAtes during 2000 - 2008, MLST method showed low discriminAtion power And the MLST method should not be Applied to outbreAk And epidemiologicAl surveillAnce of SAlmonellA PArAtyphi A. Currently, nAtionwide pArAtyphoid fever epidemics is cAused by highly clonAl isolAtes in ChinA. As the time chAnges, these isolAtes Also AccumulAte sporAdic mutAtions. Key words: SAlmonellA PArAtyphi A; Electrophoresis, gel, pulsed-field; Sequence AnAlysis; Sequence tAgged sites
Qianqian Yuan - One of the best experts on this subject based on the ideXlab platform.
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growth And survivAl of SAlmonellA PArAtyphi A in roAsted mArinAted chicken during refrigerAted storAge effect of temperAture Abuse And computer simulAtion for cold chAin mAnAgement
Food Control, 2017Co-Authors: Lihan Huang, Qianqian YuanAbstract:AbstrAct This reseArch wAs conducted to evAluAte the feAsibility of using A one-step dynAmic numericAl AnAlysis And optimizAtion method to directly construct A tertiAry model to describe the growth And survivAl of SAlmonellA PArAtyphi A (SPA) in A mArinAted roAsted chicken product. Multiple dynAmic growth And survivAl curves obtAined under different fluctuAting temperAture conditions between 4 And 35 °C were used to determine the growth kinetics of SPA. In combinAtion with AppropriAte secondAry models, the study exAmined both growth And survivAl of SPA simultAneously by An integrAted one-step ApproAch using A set of differentiAl equAtions. The estimAted minimum growth temperAture (Tmin) of SPA wAs 8.91 °C, mAtching well with the growth chArActeristics of this microorgAnism. The growth At temperAtures Above Tmin And the survivAl below Tmin wAs AccurAtely simulAted by the predictive models. For model development, the root meAn squAre error (RMSE) wAs 0.26 log CFU/g. The predictive models And kinetic pArAmeters were vAlidAted using two dynAmic growth And survivAl curves Along with one isothermAl thermAl growth curve. The vAlidAtion Also showed thAt the models were AccurAte in predicting the growth And survivAl of the bActerium, with the RMSE of predictions only 0.52 log CFU/g. The errors of predictions were within normAl experimentAl errors. The results of this work mAy be used to predict the chAnge in the populAtion of SPA in the mArinAted roAsted chickens in the cold chAin And during temperAture Abuse And to conduct risk Assessment of this pAthogen.
