scholarly journals Safety and Protective Efficacy of Intramuscular Vaccination with a Live aroA Derivative of Pasteurella multocida B:2 against Experimental Hemorrhagic Septicemia in Calves

2007 ◽  
Vol 75 (12) ◽  
pp. 5837-5844 ◽  
Author(s):  
Mark P. Dagleish ◽  
J. Christopher Hodgson ◽  
Saeed Ataei ◽  
Anna Finucane ◽  
Jeanie Finlayson ◽  
...  
Keyword(s):  
Pasteurella Multocida ◽  
Wild Type Strain ◽  
Protective Efficacy ◽  
Vaccine Dose ◽  
Immunoglobulin M ◽  
Wild Type ◽  
Amyloid A ◽  
Challenge Control ◽  
Temperature Responses ◽  
Dose Dependent

ABSTRACT Three groups of five calves, namely, V1, V2, and V3, were immunized intramuscularly at 4 and 8 weeks of age with ca. 109, 108, and 107 CFU, respectively, of a derivative of Pasteurella multocida B:2 wild-type strain 85020 containing a deletion in the aroA gene (strain JRMT12). The first and second vaccinations resulted in significantly (P < 0.01) higher rectal temperature responses in groups V1 and V2 than in group V3. Serum immunoglobulin M (IgM) and IgG titers did not increase in any group until after the second vaccination and were then significantly higher in groups V1 and V2 than in group V3 (P = 0.001 for both IgM and IgG). All vaccinated groups and three unvaccinated challenge control calves (group CC) were injected subcutaneously at 10 weeks of age with ca. 107 CFU of strain 85020. Vaccinated calves survived the challenge, but two CC animals developed clinical disease and were killed for humane reasons. After challenge, mean serum amyloid A concentrations were significantly higher (P < 0.001) in the CC group than in the vaccinated groups. Postmortem examination revealed that calves in the CC group showed the most extensive range of bacteriologically positive tissues and gross and histopathological lesions. Overall, a clear dose-dependent response was present, with those receiving a higher vaccine dose being less affected clinically, bacteriologically, and pathologically by the wild-type challenge. The V2 treatment appeared to give the best combination of high immune response, protection, and safety.

Competitiveness in root colonization by Pseudomonas putida requires the rpoS gene

2001 ◽  
Vol 47 (1) ◽  
pp. 41-48 ◽  
Author(s):  
Charles D Miller ◽  
Young-Cheol Kim ◽  
Anne J Anderson
Keyword(s):  
Pseudomonas Putida ◽  
Culture Medium ◽  
Wild Type Strain ◽  
Root Colonization ◽  
Plant Root ◽  
Wild Type ◽  
Rpos Gene ◽  
Activated Oxygen ◽  
Increased Sensitivity ◽  
Dose Dependent

The rpoS gene in Pseudomonas putida was essential for plant root colonization under competitive conditions from other microbes. The RpoS- mutant survived less well than the wild-type strain in culture medium, and unlike the wild-type, failed to colonize the roots in a peat matrix containing an established diverse microflora. The RpoS-deficient P. putida isolate was generated by insertion of a glucuronidase-npt cassette into the rpoS gene. The RpoS- mutant had dose-dependent increased sensitivity to oxidative stress and produced Mn-superoxide dismutase activity earlier than the parent. While extracts from wild-type P. putida stationary-phase cells contained three isozymes of catalase (CatA, CatB, and CatC), the σ38-deficient P. putida lacked CatB. These results are consistent with previous findings that CatB is induced in stationary-phase.Key words: catalase, starvation, activated oxygen species.

scholarly journals Reproduction and endoreduplication in Drosophila melanogaster Meig. when influenced by lead nitrate

2020 ◽  
Vol 27 ◽  
pp. 303-308
Author(s):  
V. Yu. Strashnyuk ◽  
O. V. Taglina
Keyword(s):  
Drosophila Melanogaster ◽  
Salivary Glands ◽  
Type Strain ◽  
Wild Type Strain ◽  
Lead Nitrate ◽  
Wild Type ◽  
Reproductive Ability ◽  
Dose Dependent Decrease ◽  
Drosophila Cells ◽  
Dose Dependent

Aim. The purpose of investigation was to study the reproductive ability and polyteny degree of chromosomes in Drosophila melanogaster Meig. under the influence of various concentrations of lead nitrate. Methods. Canton-S wild-type strain was used as the material. Flies developed on standard sugar-yeast medium, to which in the experiment lead nitrate was added in concentrations of 0.1, 1, and 10 mg/ml. The reproductive ability of the strain was evaluated by the number of adult offspring. The polyteny degree of chromosomes was studied on squashed preparations of larva salivary glands stained with acetoorsein by cytomorphometry. The preparations were obtained at late 3rd instar. Results. The number of adult offsprings decreased when lead nitrate was added to the nutrient medium: at a concentration of 0.1 mg/ml – by 22.8 %, at 1 mg/ml – by 38.9 %. A concentration of 10 mg/ml was lethal. Males showed greater sensitivity to the drug compared to females. The degree of polyteny of chromosomes in the salivary glands of larvae decreased on average by 5.0–6.5 %. Conclusions. Lead nitrate causes a significant, dose-dependent decrease in the reproductive ability of fruit flies and has a toxic effect on Drosophila cells, inhibiting the process of endoreduplication. Keywords: Drosophila melanogaster Meig., heavy metals, fecundity, giant chromosomes, polyteny.

scholarly journals Role of aspartate ammonia-lyase in Pasteurella multocida

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Zui Wang ◽  
Li Li ◽  
Peng Liu ◽  
Chen Wang ◽  
Qin Lu ◽  
...  
Keyword(s):  
Mutant Strain ◽  
Bacterial Growth ◽  
Type Strain ◽  
Pasteurella Multocida ◽  
Wild Type Strain ◽  
Luria Bertani ◽  
Economic Losses ◽  
Wild Type ◽  
Mueller Hinton ◽  
Significant Difference

Abstract Background Pasteurella multocida is responsible for a highly infectious and contagious disease in birds, leading to heavy economic losses in the chicken industry. However, the pathogenesis of this disease is poorly understood. We recently identified an aspartate ammonia-lyase (aspA) in P. multocida that was significantly upregulated under iron-restricted conditions, the protein of which could effectively protect chicken flocks against P. multocida. However, the functions of this gene remain unclear. In the present study, we constructed aspA mutant strain △aspA::kan and complementary strain C△aspA::kan to investigate the function of aspA in detail. Result Deletion of the aspA gene in P. multocida resulted in a significant reduction in bacterial growth in LB (Luria-Bertani) and MH (Mueller-Hinton) media, which was rescued by supplementation with 20 mM fumarate. The mutant strain △aspA::kan showed significantly growth defects in anaerobic conditions and acid medium, compared with the wild-type strain. Moreover, growth of △aspA::kan was more seriously impaired than that of the wild-type strain under iron-restricted conditions, and this growth recovered after supplementation with iron ions. AspA transcription was negatively regulated by iron conditions, as demonstrated by quantitative reverse transcription-polymerase chain reaction. Although competitive index assay showed the wild-type strain outcompetes the aspA mutant strain and △aspA::kan was significantly more efficient at producing biofilms than the wild-type strain, there was no significant difference in virulence between the mutant and the wild-type strains. Conclusion These results demonstrate that aspA is required for bacterial growth in complex medium, and under anaerobic, acid, and iron-limited conditions.

scholarly journals Characterization and Evaluation of a Salmonella enterica Serotype Senftenberg Mutant Created by Deletion of Virulence-Related Genes for Use as a Live Attenuated Vaccine

2016 ◽  
Vol 23 (10) ◽  
pp. 802-812 ◽  
Author(s):  
Nitin M. Kamble ◽  
John Hwa Lee
Keyword(s):  
Salmonella Enterica ◽  
Type Strain ◽  
Wild Type Strain ◽  
Protective Efficacy ◽  
Control Group ◽  
Intestinal Loop ◽  
Wild Type ◽  
Exchange Method ◽  
Content Type

ABSTRACTNatural infections of chickens withSalmonella entericasubsp.entericaserovar Senftenberg (S.Senftenberg) are characterized by low-level intestinal invasiveness and insignificant production of antibodies. In this study, we investigated the potential effects oflonandcpxRgene deletions on the invasiveness ofS. Senftenberg into the intestinal epithelium of chickens and its ability to induce an immune response, conferring protection againstS. Senftenberg infection. With the allelic exchange method, we developed JOL1596 (Δlon), JOL1571 (ΔcpxR), and JOL1587 (ΔlonΔcpxR) deletion mutants from wild-typeS. Senftenberg. Deletion of thelongene fromS. Senftenberg produced increased frequency of elongated cells, with significantly greater amounts of exopolysaccharide (EPS) than in thecpxR-deleted strain and the wild-type strain. Thein vivointestinal loop invasion assay showed a significant increase in epithelial invasiveness for JOL1596 (Δlon) and JOL1587 (ΔlonΔcpxR), compared to JOL1571 (ΔcpxR) and the wild-type strain. Furthermore, theS. Senftenberg wild-type and mutant strains were internalized at high levels inside activated abdominal macrophages from chicken. Thein vivoinoculation of JOL1587 (ΔlonΔcpxR) into chickens led to colonization of the liver, spleen, and cecum for a short time. Chickens inoculated with JOL1587 (ΔlonΔcpxR) showed significant increases in humoral, mucosal, and cellular immune responses specific toS. Senftenberg antigens. Postchallenge, compared to the control group, the JOL1587 (ΔlonΔcpxR)-inoculated chickens showed not only lower persistence but also faster clearance of wild-typeS. Senftenberg from the cecum. We conclude that the increased intestinal invasiveness and colonization of internal organs exhibited by JOL1587 (ΔlonΔcpxR) led to the establishment of immunogenicity and conferred protective efficacy againstS. Senftenberg infections in chickens.

scholarly journals The pnhA Gene of Pasteurella multocida Encodes a Dinucleoside Oligophosphate Pyrophosphatase Member of the Nudix Hydrolase Superfamily

2005 ◽  
Vol 187 (16) ◽  
pp. 5809-5817 ◽  
Author(s):  
Tonia Urick ◽  
Chien I-Chang ◽  
Ellen Arena ◽  
WenLian Xu ◽  
Maurice J. Bessman ◽  
...  
Keyword(s):  
Type Strain ◽  
Pasteurella Multocida ◽  
Wild Type Strain ◽  
Divalent Metal ◽  
Nudix Hydrolase ◽  
Alkaline Ph ◽  
Wild Type ◽  
Optimal Activity ◽  
Diadenosine Pentaphosphate ◽  
Hydrolysis Of

ABSTRACT The pnhA gene of Pasteurella multocida encodes PnhA, which is a member of the Nudix hydrolase subfamily of dinucleoside oligophosphate pyrophosphatases. PnhA hydrolyzes diadenosine tetra-, penta-, and hexaphosphates with a preference for diadenosine pentaphosphate, from which it forms ATP and ADP. PnhA requires a divalent metal cation, Mg2+ or Mn2+, and prefers an alkaline pH of 8 for optimal activity. A P. multocida strain that lacked a functional pnhA gene, ACP13, was constructed to further characterize the function of PnhA. The cellular size of ACP13 was found to be 60% less than that of wild-type P. multocida, but the growth rate of ACP13 and its sensitivity to heat shock conditions were similar to those of the wild type, and the wild-type cell size was restored in the presence of a functional pnhA gene. Wild-type and ACP13 strains were tested for virulence by using the chicken embryo lethality model, and ACP13 was found to be up to 1,000-fold less virulent than the wild-type strain. This is the first study to use an animal model in assessing the virulence of a bacterial strain that lacked a dinucleoside oligophosphate pyrophosphatase and suggests that the pyrophosphatase PnhA, catalyzing the hydrolysis of diadenosine pentaphosphates, may also play a role in facilitating P. multocida pathogenicity in the host.

scholarly journals Development and Evaluation of a Live Attenuated Egg-Based Camelpox Vaccine

2021 ◽  
Vol 8 ◽  
Author(s):  
Kuandyk Zhugunissov ◽  
Sanat Kilibayev ◽  
Muratbay Mambetaliyev ◽  
Kunsulu Zakarya ◽  
Markhabat Kassenov ◽  
...  
Keyword(s):  
Virus Strain ◽  
Wild Type Strain ◽  
Protective Efficacy ◽  
Chorioallantoic Membrane ◽  
Economic Loss ◽  
Viral Disease ◽  
Wild Type ◽  
Post Vaccination ◽  
Chicken Eggs ◽  
Embryonated Chicken

Camelpox is an infectious viral disease of camels reported in all the camel-breeding areas of Africa, north of the equator, the Middle East and Asia. It causes huge economic loss to the camel industry. We developed a live camelpox virus vaccine candidate using an attenuated strain and evaluated its safety, immunogenicity and protective efficacy in camels. The attenuated virus strain was generated from the camelpox wild-type strain M-96 by 40 consecutive passages on the chorioallantoic membrane of 11-day-old embryonated chicken eggs, henceforth called KM-40 strain. Reversion to virulence of the KM-40 strain was evaluated in camels by three serial passages, confirmed its inability to revert to virulence and its overdose administration was also found safe. Studies of immunogenicity and protective efficacy of the candidate vaccine KM-40 strain in camels was carried out using the dose of 5 x 104.0 EID50. Our data showed complete protection against the challenge infection using the virulent wild-type camelpox virus strain M-96 (dose of 105.0 EID50) which was evaluated at 1, 3, 6 and 12 months post vaccination. In summary, our candidate live attenuated egg-based camelpox vaccine strain KM-40 was found safe, protective, and thus has the potential to use safely in field conditions.

scholarly journals Live Attenuated Influenza H7N3 Vaccine is Safe, Immunogenic and Confers Protection in Animal Models

2014 ◽  
Vol 8 (1) ◽  
pp. 154-162 ◽  
Author(s):  
Andrey Rekstin ◽  
Yulia Desheva ◽  
Irina Kiseleva ◽  
Ted Ross ◽  
David Swayne ◽  
...  
Keyword(s):  
Animal Models ◽  
Influenza A ◽  
Protective Efficacy ◽  
Influenza Virus Infection ◽  
Vaccine Dose ◽  
Wild Type ◽  
Highly Pathogenic ◽  
Protection Against Infection ◽  
Homologous Challenge ◽  
H7n3 Virus

Background:In 2003 the outbreak of highly pathogenic H7 avian influenza occurred in the Netherlands. The avian H7 virus causing the outbreak was also detected in humans; one person died of pneumonia and acute respiratory distress syndrome. Our paper describes preclinical studies of a H7N3 live attenuated influenza A vaccine (LAIV) candidate in various animal models.Objectives:To study safety, immunogenicity and protection of H7N3 LAIV candidate in mice, ferrets and chickens.Methods:The vaccine was generated by a classical reassortment between low pathogenicity A/mallard/Netherlands/00 (H7N3) virus and A/Leningrad4/17/57 (H2N2) master donor virus (MDV).Results:Immunogenicity was found that H7N3 LAIV was similar to the MDV in terms of replication in the respiratory organs of mice and failed to replicate in mouse brains. One dose of a H7N3 LAIV elicited measurable antibody response and it was further boosted with a second vaccine dose. Immunization of mice with H7N3 LAIV provided protection against infection following a homologous challenge with wild type H7N3 virus. Attenuated phenotype of H7N3 LAIV has been confirmed in ferrets. Immunogenicity and protective efficacy of H7N3 LAIV in ferrets were also demonstrated. The vaccine protected animals from subsequent infection with wild type H7N3 virus. The results of histopathology study revealed that inoculation of H7N3 LAIV in ferrets did not cause any inflammation or destructive changes in lungs.Lack of H7N3 LAIV replication in chicken demonstrated complete safety of this preparation for poultry.Conclusion:Results of our study suggest that new H7N3 LAIV candidate is safe, immunogenic and protects from homologues influenza virus infection in mice and ferrets.

scholarly journals The lipopolysaccharide outer core transferase genes pcgD and hptE contribute differently to the virulence of Pasteurella multocida in ducks

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Xinxin Zhao ◽  
Hui Shen ◽  
Sheng Liang ◽  
Dekang Zhu ◽  
Mingshu Wang ◽  
...  
Keyword(s):  
Membrane Permeability ◽  
Outer Membrane ◽  
Type Strain ◽  
Pasteurella Multocida ◽  
Wild Type Strain ◽  
Outer Core ◽  
High Dose ◽  
Wild Type ◽  
Virulence Attenuation ◽  
Outer Membrane Permeability

AbstractFowl cholera caused by Pasteurella multocida exerts a massive economic burden on the poultry industry. Lipopolysaccharide (LPS) is essential for the growth of P. multocida genotype L1 strains in chickens and specific truncations to the full length LPS structure can attenuate bacterial virulence. Here we further dissected the roles of the outer core transferase genes pcgD and hptE in bacterial resistance to duck serum, outer membrane permeability and virulence in ducks. Two P. multocida mutants, ΔpcgD and ΔhptE, were constructed, and silver staining confirmed that they all produced truncated LPS profiles. Inactivation of pcgD or hptE did not affect bacterial susceptibility to duck serum and outer membrane permeability but resulted in attenuated virulence in ducks to some extent. After high-dose inoculation, ΔpcgD showed remarkably reduced colonization levels in the blood and spleen but not in the lung and liver and caused decreased injuries in the spleen and liver compared with the wild-type strain. In contrast, the ΔhptE loads declined only in the blood, and ΔhptE infection caused decreased splenic lesions but also induced severe hepatic lesions. Furthermore, compared with the wild-type strain, ΔpcgD was significantly attenuated upon oral or intramuscular challenge, whereas ΔhptE exhibited reduced virulence only upon oral infection. Therefore, the pcgD deletion caused greater virulence attenuation in ducks, indicating the critical role of pcgD in P. multocida infection establishment and survival.

scholarly journals Efficacy of Vaccination of Calves against Hemorrhagic Septicemia with a Live aroA Derivative of Pasteurella multocida B:2 by Two Different Routes of Administration

2005 ◽  
Vol 73 (3) ◽  
pp. 1475-1481 ◽  
Author(s):  
J. Christopher Hodgson ◽  
Anna Finucane ◽  
Mark P. Dagleish ◽  
Saeed Ataei ◽  
Roger Parton ◽  
...  
Keyword(s):  
Pasteurella Multocida ◽  
Wild Type ◽  
Live Attenuated Vaccine ◽  
Whole Cells ◽  
Routes Of Administration ◽  
Amyloid A ◽  
Unvaccinated Control ◽  
The Mean ◽  
Serotype B ◽  
And Control

ABSTRACT Two groups of four calves each were immunized either intramuscularly (i.m. vaccinated) or intranasally (i.n. vaccinated) at 2 and 6 weeks of age with ca. 109 CFU of a derivative of P. multocida serotype B:2 strain 85020 containing a deletion in the aroA gene (strain JRMT12). Both groups of calves and three unvaccinated control calves were challenged subcutaneously at 8 weeks of age with ca. 107 CFU of the wild-type 85020 strain. The first and second vaccinations caused a significant pyrexia and increase in the mean demeanor score (P < 0.05) in i.m. but not i.n. vaccinated calves. Serum agglutinating activity against whole cells of P. multocida strain 85020 and immunoglobulin G antibody concentrations increased after the second vaccination in i.m. but not in i.n. vaccinated animals, and this difference was statistically significant (P < 0.05). Concentrations of serum amyloid A (SAA) increased significantly 3 h after both the primary (P < 0.05) and booster (P < 0.001) i.m. vaccinations, but not in i.n. vaccinated calves. All four i.m. vaccinated calves were solidly immune to challenge with wild-type P. multocida B:2. However, the mean rectal temperatures, demeanor scores, and serum SAA concentrations of i.n. vaccinated and control calves increased significantly (P < 0.01). Three i.n. vaccinated and two control calves were killed for humane reasons within 14 h postchallenge, and postmortem examination revealed pathological lesions consistent with hemorrhagic septicemia. These data showed that the aroA mutant strain, given i.m. as two doses 4 weeks apart, acted as an effective live-attenuated vaccine strain to protect calves against challenge with the virulent parent strain.

scholarly journals Protective Effect of Nasal Colonisation with ∆cps/piaA and ∆cps/proABCStreptococcus pneumoniae Strains against Recolonisation and Invasive Infection

Vaccines ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 261
Author(s):  
Elisa Ramos-Sevillano ◽  
Giuseppe Ercoli ◽  
José Afonso Guerra-Assunção ◽  
Philip Felgner ◽  
Rafael Ramiro de Assis ◽  
...  
Keyword(s):  
Type Strain ◽  
Wild Type Strain ◽  
Protective Efficacy ◽  
Published Data ◽  
Invasive Infection ◽  
Wild Type ◽  
Array Measurements ◽  
Infection Models ◽  
Effective Option ◽  
Preventative Strategy

Rationale: Nasopharyngeal administration of live virulence-attenuated Streptococcus pneumoniae strains is a potential novel preventative strategy. One target for creating reduced virulence S. pneumoniae strains is the capsule, but loss of the capsule reduces the duration of S. pneumoniae colonisation in mice which could impair protective efficacy against subsequent infection. Objectives: To assess protective efficacy of nasopharyngeal administration of unencapsulated S. pneumoniae strains in murine infection models. Methods: Strains containing cps locus deletions combined with the S. pneumoniae virulence factors psaA (reduces colonisation) or proABC (no effect on colonisation) were constructed and their virulence phenotypes and ability to prevent recolonisation or invasive infection assessed using mouse infection models. Serological responses to colonisation were compared between strains using ELISAs, immunoblots and 254 S. pneumoniae protein antigen array. Measurements and Main Results: The ∆cps/piaA and ∆cps/proABC strains were strongly attenuated in virulence in both invasive infection models and had a reduced ability to colonise the nasopharynx. ELISAs, immunoblots and protein arrays showed colonisation with either strain stimulated weaker serological responses than the wild type strain. Mice previously colonised with these strains were protected against septicaemic pneumonia but, unlike mice colonised with the wild type strain, not against S. pneumoniae recolonisation. Conclusions: Colonisation with the ∆cps/piaA and ∆cps/proABC strains prevented subsequent septicaemia, but in contrast, to published data for encapsulated double mutant strains they did not prevent recolonisation with S. pneumoniae. These data suggest targeting the cps locus is a less effective option for creating live attenuated strains that prevent S. pneumoniae infections.

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