scholarly journals Shigella Outer Membrane Protein PSSP-1 Is Broadly Protective against Shigella Infection

2015 ◽  
Vol 22 (4) ◽  
pp. 381-388 ◽  
Author(s):  
Jae-Ouk Kim ◽  
Semi Rho ◽  
Su Hee Kim ◽  
Heejoo Kim ◽  
Hyo Jin Song ◽  
...  
Keyword(s):  
Shigella Flexneri ◽  
Serum Antibody ◽  
Surface Protein ◽  
Cross Protection ◽  
Antibody Responses ◽  
Shigella Dysenteriae ◽  
Mouse Lung ◽  
Protein Antigens ◽  
Content Type ◽  
Shigella Boydii

ABSTRACTIn developing countries,Shigellais a primary cause of diarrhea in infants and young children. Although antibiotic therapy is an effective treatment for shigellosis, therapeutic options are narrowing due to the emergence of antibiotic resistance. Thus, preventive vaccination could become the most efficacious approach for controlling shigellosis. We have identified several conserved protein antigens that are shared by multipleShigellaserotypes and species. Among these, one antigen induced cross-protection against experimental shigellosis, and we have named it pan-Shigellasurface protein 1 (PSSP-1). PSSP-1-induced protection requires a mucosal administration route and coadministration of an adjuvant. When PSSP-1 was administered intranasally, it induced cross-protection againstShigella flexneriserotypes 2a, 5a, and 6,Shigella boydii,Shigella sonnei, andShigella dysenteriaeserotype 1. Intradermally administered PSSP-1 induced strong serum antibody responses but failed to induce protection in the mouse lung pneumonia model. In contrast, intranasal administration elicited efficient local and systemic antibody responses and production of interleukin 17A and gamma interferon. Interestingly, blood samples from patients with recent-onset shigellosis showed variable but significant mucosal antibody responses to other conservedShigellaprotein antigens but not to PSSP-1. We suggest that PSSP-1 is a promising antigen for a broadly protective vaccine againstShigella.

scholarly journals Stable Chromosomal Expression of Shigella flexneri 2a and 3a O-Antigens in the Live Salmonella Oral Vaccine Vector Ty21a

2017 ◽  
Vol 24 (12) ◽  
Author(s):  
Madushini N. Dharmasena ◽  
Manuel Osorio ◽  
Kazuyo Takeda ◽  
Scott Stibitz ◽  
Dennis J. Kopecko
Keyword(s):  
Oral Vaccine ◽  
Shigella Flexneri ◽  
Serum Antibody ◽  
Vaccine Vector ◽  
Shigella Dysenteriae ◽  
Antigenic Determinants ◽  
Content Type ◽  
O Antigen ◽  
Shigella Flexneri 2A ◽  
O Antigens

ABSTRACT We have been exploring the use of the live attenuated Salmonella enterica serovar Typhi Ty21a vaccine strain as a versatile oral vaccine vector for the expression and delivery of multiple foreign antigens, including Shigella O-antigens. In this study, we separately cloned genes necessary for the biosynthesis of the Shigella flexneri serotype 2a and 3a O-antigens, which have been shown to provide broad cross-protection to multiple disease-predominant S. flexneri serotypes. The cloned S. flexneri 2a rfb operon, along with bgt and gtrII, contained on the SfII bacteriophage, was sufficient in Ty21a to express the heterologous S. flexneri 2a O-antigen containing the 3,4 antigenic determinants. Further, this rfb operon, along with gtrA, gtrB, and gtrX contained on the Sfx bacteriophage and oac contained on the Sf6 bacteriophage, was sufficient to express S. flexneri 3a O-antigen containing the 6, 7, and 8 antigenic determinants. Ty21a, with these plasmid-carried or chromosomally inserted genes, demonstrated simultaneous and stable expression of homologous S. Typhi O-antigen plus the heterologous S. flexneri O-antigen. Candidate Ty21a vaccine strains expressing heterologous S. flexneri 2a or 3a lipopolysaccharide (LPS) elicited significant serum antibody responses against both homologous S. Typhi and heterologous Shigella LPS and protected mice against virulent S. flexneri 2a or 3a challenges. These new S. flexneri 2a and 3a O-antigen-expressing Ty21a vaccine strains, together with our previously constructed Ty21a strains expressing Shigella sonnei or Shigella dysenteriae 1 O-antigens, have the potential to be used together for simultaneous protection against the predominant causes of shigellosis worldwide as well as against typhoid fever.

scholarly journals Evaluation of a Culture-Dependent Algorithm and a Molecular Algorithm for Identification ofShigellaspp.,Escherichia coli, and EnteroinvasiveE. coli

2018 ◽  
Vol 56 (10) ◽  
Author(s):  
Maaike J. C. van den Beld ◽  
Richard F. de Boer ◽  
Frans A. G. Reubsaet ◽  
John W. A. Rossen ◽  
Kai Zhou ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shigella Flexneri ◽  
Clinical Diagnostics ◽  
Shigella Dysenteriae ◽  
Identification Algorithm ◽  
Content Type ◽  
E Coli ◽  
Shigella Boydii ◽  
Discrepancy Analysis ◽  
Culture Dependent

ABSTRACTIdentification ofShigellaspp.,Escherichia coli, and enteroinvasiveE. coli(EIEC) is challenging because of their close relatedness. Distinction is vital, as infections withShigellaspp. are under surveillance of health authorities, in contrast to EIEC infections. In this study, a culture-dependent identification algorithm and a molecular identification algorithm were evaluated. Discrepancies between the two algorithms and original identification were assessed using whole-genome sequencing (WGS). After discrepancy analysis with the molecular algorithm, 100% of the evaluated isolates were identified in concordance with the original identification. However, the resolution for certain serotypes was lower than that of previously described methods and lower than that of the culture-dependent algorithm. Although the resolution of the culture-dependent algorithm is high, 100% of noninvasiveE. coli,Shigella sonnei, andShigella dysenteriae, 93% ofShigella boydiiand EIEC, and 85% ofShigella flexneriisolates were identified in concordance with the original identification. Discrepancy analysis using WGS was able to confirm one of the used algorithms in four discrepant results. However, it failed to clarify three other discrepant results, as it added yet another identification. Both proposed algorithms performed well for the identification ofShigellaspp. and EIEC isolates and are applicable in low-resource settings, in contrast to previously described methods that require WGS for daily diagnostics. Evaluation of the algorithms showed that both algorithms are capable of identifyingShigellaspecies and EIEC isolates. The molecular algorithm is more applicable in clinical diagnostics for fast and accurate screening, while the culture-dependent algorithm is more suitable for reference laboratories to identifyShigellaspp. and EIEC up to the serotype level.

scholarly journals Circulating Gut-Homing (α4β7+) Plasmablast Responses against Shigella Surface Protein Antigens among Hospitalized Patients with Diarrhea

2016 ◽  
Vol 23 (7) ◽  
pp. 610-617 ◽  
Author(s):  
Anuradha Sinha ◽  
Ayan Dey ◽  
Giulietta Saletti ◽  
Pradip Samanta ◽  
Partha Sarathi Chakraborty ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Surface Protein ◽  
Protein Antigens ◽  
Magnetic Cell Sorting ◽  
Content Type ◽  
Recent Onset ◽  
Microbiological Methods ◽  
Stool Specimens ◽  
Antibody Secreting Cells

Developing countries are burdened withShigelladiarrhea. Understanding mucosal immune responses associated with naturalShigellainfection is important to identify potential correlates of protection and, as such, to design effective vaccines. We performed a comparative analysis of circulating mucosal plasmablasts producing specific antibodies against highly conserved invasive plasmid antigens (IpaC, IpaD20, and IpaD120) and two recently identified surface protein antigens,pan-Shigellasurfaceprotein antigen 1 (PSSP1) and PSSP2, common to all virulentShigellastrains. We examined blood and stool specimens from 37 diarrheal patients admitted to the Infectious Diseases & Beliaghata General Hospital, Kolkata, India. The etiological agent of diarrhea was investigated in stool specimens by microbiological methods and real-time PCR. Gut-homing (α4β7+) antibody-secreting cells (ASCs) were isolated from patient blood by means of combined magnetic cell sorting and two-color enzyme-linked immunosorbent spot (ELISPOT) assay. Overall, 57% (21 of 37) and 65% (24 of 37) of the patients were positive forShigellainfection by microbiological and real-time PCR assays, respectively. The frequency of α4β7+IgG ASC responders against Ipas was higher than that observed against PSSP1 or PSSP2, regardless of theShigellaserotype isolated from these patients. Thus, α4β7+ASC responses to Ipas may be considered an indirect marker ofShigellainfection. The apparent weakness of ASC responses to PSSP1 is consistent with the lack of cross-protection induced by naturalShigellainfection. The finding that ASC responses to IpaD develop in patients with recent-onset shigellosis indicates that such responses may not be protective or may wane too rapidly and/or be of insufficient magnitude.

scholarly journals A Novel, Multiple-Antigen Pneumococcal Vaccine Protects against LethalStreptococcus pneumoniaeChallenge

2018 ◽  
Vol 87 (3) ◽  
Author(s):  
Win-Yan Chan ◽  
Claire Entwisle ◽  
Giuseppe Ercoli ◽  
Elise Ramos-Sevillano ◽  
Ann McIlgorm ◽  
...  
Keyword(s):  
Heat Shock ◽  
Protein A ◽  
Surface Protein ◽  
Surface Proteins ◽  
Rabbit Serum ◽  
Protein Antigens ◽  
Content Type ◽  
Multiple Antigen ◽  
Bacterial Lysates ◽  
Chromatography Step

ABSTRACTCurrent vaccination againstStreptococcus pneumoniaeuses vaccines based on capsular polysaccharides from selected serotypes and has led to nonvaccine serotype replacement disease. We have investigated an alternative serotype-independent approach, using multiple-antigen vaccines (MAV) prepared fromS. pneumoniaeTIGR4 lysates enriched for surface proteins by a chromatography step after culture under conditions that induce expression of heat shock proteins (Hsp; thought to be immune adjuvants). Proteomics and immunoblot analyses demonstrated that, compared to standard bacterial lysates, MAV was enriched with Hsps and contained several recognized protective protein antigens, including pneumococcal surface protein A (PspA) and pneumolysin (Ply). Vaccination of rodents with MAV induced robust antibody responses to multiple serotypes, including nonpneumococcal conjugate vaccine serotypes. Homologous and heterologous strains ofS. pneumoniaewere opsonized after incubation in sera from vaccinated rodents. In mouse models, active vaccination with MAV significantly protected against pneumonia, while passive transfer of rabbit serum from MAV-vaccinated rabbits significantly protected against sepsis caused by both homologous and heterologousS. pneumoniaestrains. Direct comparison of MAV preparations made with or without the heat shock step showed no clear differences in protein antigen content and antigenicity, suggesting that the chromatography step rather than Hsp induction improved MAV antigenicity. Overall, these data suggest that the MAV approach may provide serotype-independent protection againstS. pneumoniae.

scholarly journals Age-Specific Immunoglobulin G (IgG) and IgA to Pneumococcal Protein Antigens in a Population in Coastal Kenya

2004 ◽  
Vol 72 (6) ◽  
pp. 3331-3335 ◽  
Author(s):  
Catherine Laine ◽  
Tabitha Mwangi ◽  
Claudette M. Thompson ◽  
Jacktone Obiero ◽  
Marc Lipsitch ◽  
...  
Keyword(s):  
Immunoglobulin G ◽  
Protein A ◽  
Age Groups ◽  
Surface Protein ◽  
The Elderly ◽  
Antibody Responses ◽  
Sub Saharan Africa ◽  
Protein Antigens ◽  
Coastal Kenya ◽  
Iga Antibody

ABSTRACT Streptococcus pneumoniae is the primary etiological agent of community-acquired pneumonia and a major cause of meningitis and bacteremia. Three conserved pneumococcal proteins—pneumolysin, pneumococcal surface adhesin A (PsaA), and pneumococcal surface protein A (PspA)—are currently being investigated as vaccine candidates. Such protein-based vaccines, if proven effective, could provide a cheaper alternative to conjugate vaccine formulae. Few data from sub-Saharan Africa exist concerning the development of natural antibody to these antigens, however. To investigate the age-specific development of antiprotein immunoglobulin G (IgG) and IgA antibody responses, the sera of 220 persons 2 weeks to 84 years of age from coastal Kenya were assayed using enzyme-linked immunosorbent assays. IgG and IgA antibody responses to each antigen were observed in all age groups. Serum concentrations of IgG and IgA antibody responses to PspA and PdB (a recombinant toxoid derivative of pneumolysin), but not to PsaA, increased significantly with age (P < 0.001). No decline was observed in the sera of the elderly. Anti-protein IgG concentrations were only weakly correlated (0.30 < r < 0.56; P < 0.0001), as were IgA concentrations (0.24 < r < 0.54; P < 0.0001).

scholarly journals Rapid Detection of Serum Antibody by Dual-Path Platform VetTB Assay in White-Tailed Deer Infected with Mycobacterium bovis

2013 ◽  
Vol 20 (6) ◽  
pp. 907-911 ◽  
Author(s):  
Konstantin P. Lyashchenko ◽  
Rena Greenwald ◽  
Javan Esfandiari ◽  
Daniel J. O'Brien ◽  
Stephen M. Schmitt ◽  
...  
Keyword(s):  
Diagnostic Accuracy ◽  
Mycobacterium Bovis ◽  
Skin Testing ◽  
Serum Antibody ◽  
Antibody Responses ◽  
Antibody Detection ◽  
Serum Samples ◽  
Content Type ◽  
In The Wild ◽  
Free Ranging

ABSTRACTBovine tuberculosis (TB) in cervids remains a significant problem affecting farmed herds and wild populations. Traditional skin testing has serious limitations in certain species, whereas emerging serological assays showed promising diagnostic performance. The recently developed immunochromatographic dual-path platform (DPP) VetTB assay has two antigen bands, T1 (MPB83 protein) and T2 (CFP10/ESAT-6 fusion protein), for antibody detection. We evaluated the diagnostic accuracy of this test by using serum samples collected from groups of white-tailed deer experimentally inoculated withMycobacterium bovis,M. aviumsubsp.paratuberculosis, orM. bovisBCG Pasteur. In addition, we used serum samples from farmed white-tailed deer in herds with no history of TB, as well as from free-ranging white-tailed deer culled during field surveillance studies performed in Michigan known to have bovine TB in the wild deer population. The DPP VetTB assay detected antibody responses in 58.1% of experimentally infected animals within 8 to 16 weeks postinoculation and in 71.9% of naturally infected deer, resulting in an estimated test sensitivity of 65.1% and a specificity of 97.8%. The higher seroreactivity found in deer with naturally acquiredM. bovisinfection was associated with an increased frequency of antibody responses to the ESAT-6 and CFP10 proteins, resulting in a greater contribution of these antigens, in addition to MPB83, to the detection of seropositive animals, compared with experimentalM. bovisinfection. Deer experimentally inoculated with eitherM. aviumsubsp.paratuberculosisorM. bovisBCG Pasteur did not produce cross-reactive antibodies that could be detected by the DPP VetTB assay. The present findings demonstrate the relatively high diagnostic accuracy of the DPP VetTB test for white-tailed deer, especially in the detection of naturally infected animals.

Molecular Strategies for the Detection, Identification, and Differentiation between Enteroinvasive Escherichia coli and Shigella spp.

2005 ◽  
Vol 68 (2) ◽  
pp. 239-245 ◽  
Author(s):  
CESAR I. BIN KINGOMBE ◽  
MARIA-LUCIA CERQUEIRA-CAMPOS ◽  
JEFFREY M. FARBER
Keyword(s):  
Escherichia Coli ◽  
Multiplex Pcr ◽  
Shigella Flexneri ◽  
Shigella Dysenteriae ◽  
Shigella Boydii ◽  
Epidemiological Tool ◽  
Pcr Rflp ◽  
Shigella Spp

A strategy for the detection, identification, and differentiation of enteroinvasive Escherichia coli (EIEC) and Shigella spp. has been developed. The strategy includes (i) a multiplex PCR for the amplification of two virulence genes, i.e., iuc (222 bp) and ipaH (629 bp); (ii) amplification of the ial gene (a 1,038-bp amplicon) located within a large plasmid; and (iii) restriction fragment length polymorphism (RFLP) of the ial gene amplicon. The multiplex PCR provided three patterns. Pattern 1 (iuc−/ipaH+) was found in 10 (67%) of 15 EIEC strains tested, pattern 2 (iuc+/ipaH−) in only 2 (4.4%) of 46 non-EIEC isolates, whereas pattern 3 (iuc+/ipaH+) was observed in all Shigella spp. and also in 5 (33%) of 15 EIEC strains tested. The pattern 3 EIEC strains were all positive for the ial gene. The PCR-RFLP of the ial gene amplicon using the endonuclease AclI was used to differentiate Shigella spp. from the EIEC strains that belonged to pattern 3. The ial gene was present in 21 (38%) of 56 and 6 (40%) of 15 Shigella spp. and EIEC strains tested, respectively. The PCR-RFLP of the ial gene amplicon divided the strains in two types. Type 1 did not contain the restriction enzyme site and was found in 6 (100%) of 6 EIEC strains, 4 (80%) of 5 Shigella boydii, and 4 (100%) of 4 Shigella dysenteriae strains tested. Type 2, which gave two fragments of 286 and 752 bp, was observed in 5 (83%) of 6 Shigella flexneri strains and 6 (100%) of 6 Shigella sonnei strains. Detection, identification, and differentiation of Shigella spp. and EIEC were achieved by analyses of the PCR patterns and RFLP types. To our knowledge, this is the first study to demonstrate a simple and rapid method for detecting, identifying, and differentiating, at the molecular level, Shigella spp. and EIEC strains. This method will have tremendous utility as an epidemiological tool and in helping to develop policies, risk assessments, and national and international methods for Shigella spp.

scholarly journals Molecular detection of all 34 distinct O-antigen forms of Shigella

2009 ◽  
Vol 58 (1) ◽  
pp. 69-81 ◽  
Author(s):  
Yayue Li ◽  
Boyang Cao ◽  
Bin Liu ◽  
Dan Liu ◽  
Qili Gao ◽  
...  
Keyword(s):  
Shigella Flexneri ◽  
Bacterial Species ◽  
Milk Powder ◽  
Shigella Dysenteriae ◽  
Detection Sensitivity ◽  
Clinical Samples ◽  
Shigella Boydii ◽  
O Antigen ◽  
Probe Concentration ◽  
O Antigens

Shigella is the cause of shigellosis or bacillary dysentery, the occurrence of which is estimated to be 165 million cases per year worldwide, resulting in 1.1 million deaths. Rapid and reliable assays for detecting and identifying Shigella in food, environmental and clinical samples are therefore necessary. Shigella species are traditionally identified by their O antigens. This study developed a DNA microarray targeting O-serotype-specific genes to detect all 34 distinct O-antigen forms of Shigella, including Shigella boydii types 1–18, Shigella dysenteriae types 1–13, Shigella flexneri types 1–5 and 6, and Shigella sonnei. A total of 282 strains were used to test the specificity of the microarray, including 186 Shigella and Escherichia coli representative strains, 86 Shigella clinical isolates and ten strains of other bacterial species that are commonly isolated from food or clinical stool specimens. The oligonucleotide probes were printed on the microarray in concentrations from 1 to 100 μM, and 10 μM proved to be the optimal probe concentration. The detection sensitivity for each serotype was 50 ng genomic DNA or 1 c.f.u. in 25 g milk powder sample following a 6 h enrichment in broth. The microarray is specific, sensitive and reproducible, and, to our knowledge, is the first report of a microarray for serotyping all O-antigen forms of Shigella.

scholarly journals Kinetics and Magnitude of Antibody Responses against the Conserved 47-Kilodalton Antigen and the Variable 56-Kilodalton Antigen in Scrub Typhus Patients

2011 ◽  
Vol 18 (6) ◽  
pp. 1021-1027 ◽  
Author(s):  
Hua-Wei Chen ◽  
Zhiwen Zhang ◽  
Erin Huber ◽  
Elissa Mutumanje ◽  
Chien-Chung Chao ◽  
...  
Keyword(s):  
Scrub Typhus ◽  
Secondary Infection ◽  
Systematic Investigation ◽  
Antibody Responses ◽  
Enzyme Linked Immunosorbent Assay ◽  
Orientia Tsutsugamushi ◽  
Protein Antigens ◽  
Content Type ◽  
Molecular Sizes ◽  
Kinetics Of

ABSTRACTWestern blot analysis ofOrientia tsutsugamushiwhole-cell lysates with scrub typhus patient sera has identified at least five protein antigens ofO. tsutsugamushiwith molecular sizes of 22 kDa, 47 kDa, 56 kDa, 58 kDa, and 110 kDa. In this study, sera from serial bleedings of 108 patients were used to study the kinetics and the magnitude of specific antibody responses against the 47-kDa and 56-kDa antigens. Recombinant protein of the conserved 47-kDa antigen (r47b) or a mixture of truncated 56-kDa antigen (r56s) from three prototype strains was used as the antigen in an enzyme-linked immunosorbent assay (ELISA). Our results showed that 76% and 93% of these patients had elevated IgM and IgG against r47b, respectively, and 98% and 100% had elevated IgM and IgG against r56s, respectively. The kinetics of antibody responses against r47b and r56s can be grouped into three patterns. In the first type of response, IgM and IgG against r47b and r56s appeared about the same time. The IgM and IgG titers against r56s were much higher than those against r47b. In the second type of response, induction of IgM appeared to be similar to that in the first type. The major difference to the first type is that the IgG titers against r47b were induced at least 1 week later than those against the r56s. The third type showed strong IgG responses against both r47b and r56s, and low or no IgM responses indicated a secondary infection. This is the first systematic investigation of antibody response kinetics against the conserved 47-kDa antigen versus the variable 56-kDa antigen in scrub typhus patients.

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