scholarly journals The Live Attenuated Actinobacillus pleuropneumoniae Triple-Deletion Mutant ΔapxICΔapxIICΔapxIV-ORF1Strain, SLW05, Immunizes Pigs against Lethal Challenge with Haemophilus parasuis

2012 ◽  
Vol 20 (2) ◽  
pp. 134-139 ◽  
Author(s):  
Shulin Fu ◽  
Jiwen Ou ◽  
Minmin Zhang ◽  
Juan Xu ◽  
Huazhen Liu ◽  
...  
Keyword(s):  
Deletion Mutant ◽  
Lethal Dose ◽  
Interleukin 2 ◽  
Actinobacillus Pleuropneumoniae ◽  
Economic Losses ◽  
Respiratory Pathogens ◽  
Haemophilus Parasuis ◽  
Lethal Challenge ◽  
Content Type ◽  
Novel Approach

ABSTRACTHaemophilus parasuisandActinobacillus pleuropneumoniaeboth belong to the familyPasteurellaceaeand are major respiratory pathogens that cause large economic losses in the pig industry worldwide. We previously constructed an attenuatedA. pleuropneumoniaeserovar 1 live vaccine prototype, SLW05 (ΔapxICΔapxIICΔapxIV-ORF1), which is able to produce nontoxic but immunogenic ApxIA, ApxIIA, and ApxIVA. This triple-deletion mutant strain was shown to elicit protective immunity against virulentA. pleuropneumoniae. In the present study, we investigated whether immunization with SLW05 could also protect against lethal challenge with virulentH. parasuisSH0165 (serovar 5) or MD0322 (serovar 4). The SLW05 strain was found to elicit a strong humoral antibody response in pigs and to confer significant protection against challenge with a lethal dose ofH. parasuisSH0165 or MD0322. IgG subtype analysis revealed that SLW05 induces a bias toward a Th1-type immune response and stimulates interleukin 2 (IL-2) and gamma interferon (IFN-γ) production. Moreover, antisera from SLW05-vaccinated pigs efficiently inhibited bothA. pleuropneumoniaeandH. parasuisgrowth in a whole-blood assay. This is the first report that a live attenuatedA. pleuropneumoniaevaccine with SLW05 can protect against lethalH. parasuisinfection, which provides a novel approach for developing an attenuatedH. parasuisvaccine.

scholarly journals Engineering and Preclinical Evaluation of Attenuated Nontyphoidal Salmonella Strains Serving as Live Oral Vaccines and as Reagent Strains

2011 ◽  
Vol 79 (10) ◽  
pp. 4175-4185 ◽  
Author(s):  
Sharon M. Tennant ◽  
Jin-Yuan Wang ◽  
James E. Galen ◽  
Raphael Simon ◽  
Marcela F. Pasetti ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Lethal Dose ◽  
Invasive Disease ◽  
Oral Immunization ◽  
Oral Vaccines ◽  
Wild Type ◽  
Lethal Challenge ◽  
Antibiotic Resistant ◽  
Content Type ◽  
Serovar Typhimurium

ABSTRACTWhile nontyphoidalSalmonella(NTS) has long been recognized as a cause of self-limited gastroenteritis, it is becoming increasingly evident that multiple-antibiotic-resistant strains are also emerging as important causes of invasive bacteremia and focal infections, resulting in hospitalizations and deaths. We have constructed attenuatedSalmonella entericaserovar Typhimurium andSalmonella entericaserovar Enteritidis strains that can serve as live oral vaccines and as “reagent strains” for subunit vaccine production in a safe and economical manner. Prototype attenuated vaccine strains CVD 1921 and CVD 1941, derived from the invasive wild-type strainsS. TyphimuriumI77 andS. EnteritidisR11, respectively, were constructed by deletingguaBA, encoding guanine biosynthesis, andclpP, encoding a master protease regulator. TheclpPmutation resulted in a hyperflagellation phenotype. An additional deletion infliDyielded reagent strains CVD 1923 and CVD 1943, respectively, which export flagellin monomers. Oral 50% lethal dose (LD50) analyses showed that the NTS vaccine strains were all highly attenuated in mice. Oral immunization with CVD 1921 or CVD 1923 protected mice against lethal challenge with wild-typeS. TyphimuriumI77. Immunization with CVD 1941 but not CVD 1943 protected mice against lethal infection withS. EnteritidisR11. Immune responses induced by these strains included high levels of serum IgG anti-lipopolysaccharide (LPS) and anti-flagellum antibodies, with titers increasing progressively during the immunization schedule. SinceS. TyphimuriumandS. Enteritidisare the most common NTS serovars associated with invasive disease, these findings can pave the way for development of a highly effective, broad-spectrum vaccine against invasive NTS.

scholarly journals Protective Immunity against Tularemia Provided by an Adenovirus-Vectored Vaccine Expressing Tul4 of Francisella tularensis

2012 ◽  
Vol 19 (3) ◽  
pp. 359-364 ◽  
Author(s):  
Ravinder Kaur ◽  
Shan Chen ◽  
Maria T. Arévalo ◽  
Qingfu Xu ◽  
Yanping Chen ◽  
...  
Keyword(s):  
Single Dose ◽  
Francisella Tularensis ◽  
Virulent Strain ◽  
Lethal Dose ◽  
Protein Vaccine ◽  
Lethal Challenge ◽  
Live Attenuated Vaccine ◽  
Content Type ◽  
Skin Contact ◽  
Vectored Vaccine

ABSTRACTFrancisella tularensis, a category A bioterrorism agent, is a highly infectious organism that is passed on via skin contact and inhalation routes. A live attenuated vaccine strain (LVS) has been developed, but it has not been licensed for public use by the FDA due to safety concerns. Thus, there exists a need for a safer and improved vaccine. In this study, we have constructed a replication-incompetent adenovirus, Ad/opt-Tul4, carrying a codon-optimized gene for expression of a membrane protein, Tul4, ofF. tularensisLVS. Its ability to protect against lethal challenge and its immunogenicity were evaluated in a murine model. An intramuscular injection of a single dose (1 × 107PFU) of Ad/opt-Tul4 elicited a robust Tul4-specific antibody response. Assays suggest a Th1-driven response. A single dose elicited 20% protection against challenge with 100 × 50% lethal dose (LD50)F. tularensisLVS; two additional booster shots resulted in 60% protection. In comparison, three doses of 5 μg recombinant Tul4 protein did not elicit significant protection against challenge. Therefore, the Ad/opt-Tul4 vaccine was more effective than the protein vaccine, and protection was dose dependent. Compared to LVS, the protection rate is lower, but an adenovirus-vectored vaccine may be more attractive due to its enhanced safety profile and mucosal route of delivery. Furthermore, simple genetic modification of the vaccine may potentially produce antibodies protective against a fully virulent strain ofF. tularensis. Our data support the development and further research of an adenovirus-vectored vaccine against Tul4 ofF. tularensisLVS.

scholarly journals Draft Genome Sequence of Actinobacillus pleuropneumoniae Serotype 7 Strain S-8

2012 ◽  
Vol 194 (23) ◽  
pp. 6606-6607 ◽  
Author(s):  
Gang Li ◽  
Fang Xie ◽  
Yanhe Zhang ◽  
Chunlai Wang
Keyword(s):  
Genome Sequence ◽  
Draft Genome ◽  
Actinobacillus Pleuropneumoniae ◽  
Draft Genome Sequence ◽  
Economic Losses ◽  
Negative Bacterium ◽  
Swine Industry ◽  
Gram Negative ◽  
Content Type ◽  
Porcine Pleuropneumonia

ABSTRACTThe Gram-negative bacteriumActinobacillus pleuropneumoniaeis the etiological agent of porcine pleuropneumonia, a respiratory disease that leads to severe economic losses in the swine industry. For years, scientists working with it have lacked a reliable genome sequence for comparison with otherActinobacillusspecies. Here, we report the draft genome sequence ofA. pleuropneumoniaeserotype 7 (strain S-8), isolated from swine lung in China in 1992.

scholarly journals Genome-Wide Identification of Virulence Genes in Erysipelothrix rhusiopathiae: Use of a Mutant Deficient in a tagF Homolog as a Safe Oral Vaccine against Swine Erysipelas

2019 ◽  
Vol 87 (12) ◽  
Author(s):  
Yoshihiro Shimoji ◽  
Yohsuke Ogawa ◽  
Manae Tsukio ◽  
Kazumasa Shiraiwa ◽  
Sayaka Nishikawa ◽  
...  
Keyword(s):  
Clinical Symptoms ◽  
Oral Vaccine ◽  
Lethal Dose ◽  
Erysipelothrix Rhusiopathiae ◽  
Gene Encoding ◽  
Lethal Challenge ◽  
Content Type ◽  
Genome Wide ◽  
Transposon Mutants ◽  
Swine Erysipelas

ABSTRACT Swine erysipelas is caused by the Gram-positive pathogen Erysipelothrix rhusiopathiae. The swine erysipelas live vaccine in Japan, the E. rhusiopathiae Koganei 65-0.15 strain (Koganei), has been reported to cause arthritis and endocarditis. To develop a vaccine with increased safety, we used a virulent Fujisawa strain to construct transposon mutants for a total of 651 genes, which covered 38% of the coding sequence of the genome. We screened the mutants for attenuation by inoculating mice with 108 CFU of each mutant and subsequently assessed protective capability by challenging the surviving mice with 103 CFU (102 times the 50% lethal dose) of the Fujisawa strain. Of the 23 attenuated mutants obtained, 6 mutants were selected and evaluated for protective capability in pigs by comparison to that of the Koganei strain. A mutant in the ERH_0432 (tagF) gene encoding a putative CDP-glycerol glycerophosphotransferase was found to be highly attenuated and to induce humoral and cell-mediated immune responses in conventional pigs. An in-frame deletion mutant of the gene, the Δ432 mutant, was constructed, and attenuation was further confirmed in germfree piglets; three of four piglets subcutaneously inoculated with 109 CFU of the Δ432 mutant showed no apparent clinical symptoms, whereas all four of the Koganei-inoculated piglets died 3 days after inoculation. It was confirmed that conventional pigs inoculated orally or subcutaneously with the Δ432 strain were almost completely protected against lethal challenge infection. Thus, the tagF homolog mutant of E. rhusiopathiae represents a safe vaccine candidate that can be administered via the oral and subcutaneous routes.

scholarly journals Adhesion Protein ApfA of Actinobacillus pleuropneumoniae Is Required for Pathogenesis and Is a Potential Target for Vaccine Development

2012 ◽  
Vol 20 (2) ◽  
pp. 287-294 ◽  
Author(s):  
Yang Zhou ◽  
Lu Li ◽  
Zhaohui Chen ◽  
Hong Yuan ◽  
Huanchun Chen ◽  
...  
Keyword(s):  
Vaccine Development ◽  
Actinobacillus Pleuropneumoniae ◽  
Etiologic Agent ◽  
Host Cells ◽  
Economic Losses ◽  
Mouse Lung ◽  
Content Type ◽  
Humoral Immune ◽  
Fimbrial Subunit ◽  
Type Iv

ABSTRACTActinobacillus pleuropneumoniaeis the etiologic agent of porcine pleuropneumonia, which causes serious economic losses in the pig farming industry worldwide. Due to a lack of knowledge of its virulence factors and a lack of effective vaccines able to confer cross-serotype protection, it is difficult to place this disease under control. By analyzing its genome sequences, we found that type IV fimbrial subunit protein ApfA is highly conserved among different serotypes ofA. pleuropneumoniae. Our study shows that ApfA is an adhesin since its expression was greatly upregulated (135-fold) upon contact with host cells, while its deletion mutant attenuated its capability of adhesion. The inactivation ofapfAdramatically reduced the ability ofA. pleuropneumoniaeto colonize mouse lung, suggesting thatapfAis a virulence factor. Purified recombinant ApfA elicited an elevated humoral immune response and conferred robust protection against challenges withA. pleuropneumoniaeserovar 1 strain 4074 and serovar 7 strain WF83 in mice. Importantly, the anti-ApfA serum conferred significant protection against both serovar 1 and serovar 7 in mice. These studies indicate that ApfA promotes virulence through attachment to host cells, and its immunogenicity renders it a promising novel subunit vaccine candidate against infection withA. pleuropneumoniae.

scholarly journals Development and Evaluation of a Trivalent Riemerella anatipestifer-Inactivated Vaccine

2013 ◽  
Vol 20 (5) ◽  
pp. 691-697 ◽  
Author(s):  
Haiwen Liu ◽  
Xiaolan Wang ◽  
Chan Ding ◽  
Xiangan Han ◽  
Anchun Cheng ◽  
...  
Keyword(s):  
Interleukin 2 ◽  
Animal Experiments ◽  
Clinical Signs ◽  
Economic Losses ◽  
Inactivated Vaccine ◽  
Mhc I ◽  
Content Type ◽  
Riemerella Anatipestifer ◽  
Serotype 1 ◽  
Antibody Titers

ABSTRACTRiemerella anatipestiferinfections cause major economic losses in the duck industry. In this study, a trivalent inactivated vaccine ofR. anatipestifer, including strains CH3 (serotype 1), NJ3 (serotype 2), and HXb2 (serotype 10), was developed. Animal experiments showed that the ducks that received two immunizations with the vaccine were 100% protected from challenge with strains from any of the three serotypes (1, 2, or 10). No death or clinical signs of diarrhea, tremors, or limb swelling were shown in the protected ducks. Also, noR. anatipestiferbacteria were isolated from the livers or brains of the protected ducks. Furthermore, no histopathological changes were observed in the liver, spleen, or brain samples from the protected ducks during histological examination. The ducks that received two immunizations with the vaccine generated high antibody titers of 1:3,200 to 1:6,400 against the three serotypes of strains. The vaccine significantly enhanced the production of gamma interferon (IFN-γ) and interleukin 2 (IL-2) after one immunization and enhanced the production of IL-4 and IL-10 after two immunizations. In addition, real-time PCR indicated that the expression of major histocompatibility complex I (MHC-I), as well as that of CD40 and CD154 molecules, was significantly increased after one immunization, and the expressions of both MHC-I and MHC-II molecules were increased after two immunizations. Our study indicates that the vaccine can induce both humoral and cellular immunities in ducks and offer effective protection againstR. anatipestiferinfection.

scholarly journals Binding of Actinobacillus pleuropneumoniae to Phosphatidylethanolamine

2003 ◽  
Vol 71 (8) ◽  
pp. 4657-4663 ◽  
Author(s):  
Marie-Eve Jeannotte ◽  
Maan Abul-Milh ◽  
J. Daniel Dubreuil ◽  
Mario Jacques
Keyword(s):  
Bacterial Colonization ◽  
Actinobacillus Pleuropneumoniae ◽  
Host Cells ◽  
Mass Spectrometry Analysis ◽  
Economic Losses ◽  
Respiratory Pathogens ◽  
Swine Industry ◽  
Molybdenum Blue ◽  
O Antigen ◽  
Serotype 1

ABSTRACT The gram-negative bacterium Actinobacillus pleuropneumoniae is the causative agent of porcine fibrinohemorrhagic necrotizing pleuropneumonia, a disease that causes important economic losses to the swine industry worldwide. In general, the initial step of bacterial colonization is attachment to host cells. The purpose of the present study was to evaluate the binding of A. pleuropneumoniae serotype 1 to phospholipids, which are the major constituents of biological membranes. Phospholipids serve as receptors for several bacteria, including respiratory pathogens. To study this effect, we used thin-layer chromatography overlay binding assays to test commercial phospholipids such as phosphatidic acid, phosphatidylcholine, phosphatidylserine, phosphatidylinositol, phosphatidylglycerol, and phosphatidylethanolamine (PE). Our results indicate that A. pleuropneumoniae serotype 1 binds to PE but not to the other phospholipids tested. Serotypes 5b and 7, which, along with serotype 1, are the most prevalent serotypes of A. pleuropneumoniae in North America, share the ability to bind PE. Inhibition of binding with a monoclonal antibody against A. pleuropneumoniae serotype 1 O antigen and the use of isogenic lipopolysaccharide (LPS) mutants of A. pleuropneumoniae serotype 1 showed that the O antigen seems to be implicated in the binding to PE, at least for A. pleuropneumoniae serotype 1. A. pleuropneumoniae was also shown to bind to a phospholipid extracted from swine lungs by using the method of Folch. Chemical staining with molybdenum blue and ninhydrin, migration with neutral, acidic, and basic solvent systems, and mass spectrometry analysis all indicated that this lipid is PE. This study is, to the best of our knowledge, the first description of A. pleuropneumoniae binding to phospholipids. Our data also suggest that LPS O antigens could be involved in binding to PE.

scholarly journals Surface Polysaccharide Mutants Reveal that Absence of O Antigen Reduces Biofilm Formation of Actinobacillus pleuropneumoniae

2015 ◽  
Vol 84 (1) ◽  
pp. 127-137 ◽  
Author(s):  
S. Hathroubi ◽  
M. A. Hancock ◽  
J. T. Bossé ◽  
P. R. Langford ◽  
Y. D. N. Tremblay ◽  
...  
Keyword(s):  
Parental Strain ◽  
Biofilm Formation ◽  
Specific Binding ◽  
Actinobacillus Pleuropneumoniae ◽  
Economic Losses ◽  
Content Type ◽  
O Antigen ◽  
Serotype 1 ◽  
Surface Polysaccharides ◽  
Isogenic Mutants

Actinobacillus pleuropneumoniaeis a Gram-negative bacterium belonging to thePasteurellaceaefamily and the causative agent of porcine pleuropneumonia, a highly contagious lung disease causing important economic losses. Surface polysaccharides, including lipopolysaccharides (LPS) and capsular polysaccharides (CPS), are implicated in the adhesion and virulence ofA. pleuropneumoniae, but their role in biofilm formation is still unclear. In this study, we investigated the requirement for these surface polysaccharides in biofilm formation byA. pleuropneumoniaeserotype 1. Well-characterized mutants were used: an O-antigen LPS mutant, a truncated core LPS mutant with an intact O antigen, a capsule mutant, and a poly-N-acetylglucosamine (PGA) mutant. We compared the amount of biofilm produced by the parental strain and the isogenic mutants using static and dynamic systems. Compared to the findings for the biofilm of the parental or other strains, the biofilm of the O antigen and the PGA mutants was dramatically reduced, and it had less cell-associated PGA. Real-time PCR analyses revealed a significant reduction in the level ofpgaA,cpxR, andcpxAmRNA in the biofilm cells of the O-antigen mutant compared to that in the biofilm cells of the parental strain. Specific binding between PGA and LPS was consistently detected by surface plasmon resonance, but the lack of O antigen did not abolish these interactions. In conclusion, the absence of the O antigen reduces the ability ofA. pleuropneumoniaeto form a biofilm, and this is associated with the reduced expression and production of PGA.

scholarly journals Evaluation of recombinant protein superoxide dismutase of Haemophilus parasuis strain SH0165 as vaccine candidate in a mouse model

2017 ◽  
Vol 63 (4) ◽  
pp. 312-320 ◽  
Author(s):  
Ling Guo ◽  
Lei Xu ◽  
Tao Wu ◽  
Shulin Fu ◽  
Yinsheng Qiu ◽  
...  
Keyword(s):  
Immune Response ◽  
Superoxide Dismutase ◽  
Mouse Model ◽  
Inflammatory Diseases ◽  
Protective Efficacy ◽  
Lethal Dose ◽  
Haemophilus Parasuis ◽  
Humoral Immune ◽  
Novel Approach ◽  
Ifn Γ

Haemophilus parasuis can cause a severe membrane inflammation disorder. It has been documented that superoxide dismutase (SOD) is a potential target to treat systemic inflammatory diseases. Therefore, we constructed an experimental H. parasuis subunit vaccine SOD and determined the protective efficacy of SOD using a lethal dose challenge against H. parasuis serovar 4 strain MD0322 and serovar 5 strain SH0165 in a mouse model. The results demonstrated that SOD could induce a strong humoral immune response in mice and provide significant immunoprotection efficacy against a lethal dose of H. parasuis serovar 4 strain MD0322 or serovar 5 strain SH0165 challenge. IgG subtype analysis indicated SOD protein could trigger a bias toward a Th1-type immune response and induce the proliferation of splenocytes and secretion of IL-2 and IFN-γ of splenocytes. In addition, serum in mice from the SOD-immunized group could inhibit the growth of strain MD0322 and strain SH0165 in the whole-blood killing bacteria assay. This is the first report that immunization of mice with SOD protein could provide protective effect against a lethal dose of H. parasuis serovar 4 and serovar 5 challenge in mice, which may provide a novel approach against heterogeneous serovar infection of H. parasuis in future.

scholarly journals Evaluation of the Salmonella enterica Serovar Pullorum Pathogenicity Island 2 Mutant as a Candidate Live Attenuated Oral Vaccine

2015 ◽  
Vol 22 (7) ◽  
pp. 706-710 ◽  
Author(s):  
Junlei Yin ◽  
Zhao Cheng ◽  
Xiaochun Wang ◽  
Lijuan Xu ◽  
Qiuchun Li ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Clinical Symptoms ◽  
Oral Vaccine ◽  
Systemic Disease ◽  
Lethal Dose ◽  
Pathogenicity Island ◽  
Economic Losses ◽  
Control Group ◽  
Content Type ◽  
Short Period

ABSTRACTSalmonella entericaserovar Pullorum (S. Pullorum) is a highly adapted pathogen that causes pullorum disease (PD), an important systemic disease of poultry that causes severe economic losses in developing countries. In the interests of developing a safe and immunogenic oral vaccine, the efficacy of aSalmonellapathogenicity island 2 (SPI2)-deleted mutant ofS. Pullorum (S06004ΔSPI2) was evaluated in chickens. S06004ΔSPI2 was severely less virulent than the parental wild-type strain S06004 as determined by the 50% lethal dose (LD50) for 3-day-old chickens when injected intramuscularly. Two-day-old chickens immunized with a single oral dose of S06004ΔSPI2 showed no differences in body weight or clinical symptoms compared with those in the negative-control group. S06004ΔSPI2 bacteria were not isolated from livers or spleens of immunized chickens after a short period of time, and specific humoral and cellular immune responses were significantly induced. Immunized chickens were challenged withS. Pullorum strain S06004 andSalmonellaenterica serovar Gallinarum (S. Gallinarum) strain SG9 at 10 days postimmunization (dpi), and efficient protection against the challenges was observed. None of the immunized chickens died, the clinical symptoms were slight and temporary following challenge in immunized chickens compared with those in the control group, and these chickens recovered by 3 to 5 dpi. Overall, these results demonstrate that S06004ΔSPI2 can be used as a live attenuated oral vaccine.

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