scholarly journals Immunogenicity and protective efficacy of irradiated Salmonella Gallinarum against homologous challenge infection in Bovans brown chickens

2020 ◽  
Vol 24 (2) ◽  
pp. 123-138
Author(s):  
Solomon Lulie ◽  
Haile Alemayehu ◽  
Anwar Nuru ◽  
Takele Abayneh ◽  
Tadesse Eguale
Keyword(s):  
Antibody Response ◽  
Gamma Irradiation ◽  
Protective Efficacy ◽  
Statistical Significance ◽  
Challenge Infection ◽  
Large Sample Size ◽  
Salmonella Gallinarum ◽  
Commercial Vaccine ◽  
Fowl Typhoid ◽  
Homologous Challenge

Fowl typhoid is a systemic poultry disease caused by Salmonella Gallinarum (SG). It is responsible for significant economic loss, due to its severe  morbidity and mortality. An irradiated vaccine is one of the possible alternatives to prevent and control fowl typhoid. This study aimed to evaluate the safety, immunogenicity, and protective efficacy of irradiated SG using a randomized control trial in chicken. A field strain of SG was exposed to different doses of gamma irradiation to determine its effect on the viability of SG. Safety and immunogenicity were assessed by administering irradiated SG orally to 3 groups (5 each) of 5 weeks old Bovans brown chickens at 2400, 2500, and 2600 gray (Gy). The protective efficacy of 108colony forming units (CFU) of SG irradiated at 2400 Gy administered orally and subcutaneously was then evaluated using homologous challenge infection and compared with SG 9R commercial vaccine using 40, 5-week old Bovans brown chickens where the chickens were randomly assigned to 4 groups. Chickens in Group 1were exposed to 108 CFU of irradiated SG orally; Group 2 to the same dose subcutaneously; Group 3 to SG 9R strain commercial vaccine subcutaneously, Group 4 to phosphate-buffered saline (PBS) orally. Data related to survival, antibody response, and pathological lesions were recorded. Mann-Whitney U-test, Kruskal-Wallis test, and Fisher’s exact tests were used to examine for statistical  significance. Irradiation at 2600 Gy caused complete inactivation of SG whereas SG exposed to 2400 Gy showed better immunogenicity and was safe for chickens. Antibody response in a group of chickens vaccinated with irradiated SG administered subcutaneously (SC) was significantly higher than  those vaccinated with the SG 9R vaccine on day 7 (p=0.003) and day 14 (p=0.002) post-immunization. Comparative evaluation of the protective efficacy based on the mortality rate of chickens after challenge showed that 2400 Gy irradiated SG vaccine administered SC and SG 9R vaccine-induced equal protection of 50% while the irradiated vaccine administered orally protected only 10% of chickens against homologous challenge infection. SG was not isolated from the liver, spleen, and feces of chickens that survived challenge infection until the end of the experiment. Irradiated SG administered SC is shown to be a promising vaccine against fowl typhoid. Further studies using a large sample size involving tuning of irradiation dose to improve immunogenicity and use of booster vaccination are recommended. Keywords: Chicken; Fowl typhoid; Gamma irradiation; Salmonella Gallinarum; Vaccine

scholarly journals Protective Efficacy of an Orf Virus-Vector Encoding the Hemagglutinin and the Nucleoprotein of Influenza A Virus in Swine

2021 ◽  
Vol 12 ◽  
Author(s):  
Lok R. Joshi ◽  
David Knudsen ◽  
Pablo Piñeyro ◽  
Santosh Dhakal ◽  
Gourapura J. Renukaradhya ◽  
...  
Keyword(s):  
Antibody Response ◽  
Neutralizing Antibodies ◽  
Influenza A ◽  
Protective Efficacy ◽  
Swine Influenza Virus ◽  
Swine Influenza ◽  
Challenge Infection ◽  
Viral Rna ◽  
Economic Losses ◽  
Recombinant Viruses

Swine influenza is a highly contagious respiratory disease of pigs caused by influenza A viruses (IAV-S). IAV-S causes significant economic losses to the swine industry and poses challenges to public health given its zoonotic potential. Thus effective IAV-S vaccines are needed and highly desirable and would benefit both animal and human health. Here, we developed two recombinant orf viruses, expressing the hemagglutinin (HA) gene (OV-HA) or the HA and the nucleoprotein (NP) genes of IAV-S (OV-HA-NP). The immunogenicity and protective efficacy of these two recombinant viruses were evaluated in pigs. Both OV-HA and OV-HA-NP recombinants elicited robust virus neutralizing antibody response in pigs, with higher levels of neutralizing antibodies (NA) being detected in OV-HA-NP-immunized animals pre-challenge infection. Although both recombinant viruses elicited IAV-S-specific T-cell responses, the frequency of IAV-S-specific proliferating CD8+ T cells upon re-stimulation was higher in OV-HA-NP-immunized animals than in the OV-HA group. Importantly, IgG1/IgG2 isotype ELISAs revealed that immunization with OV-HA induced Th2-biased immune responses, whereas immunization with OV-HA-NP virus resulted in a Th1-biased immune response. While pigs immunized with either OV-HA or OV-HA-NP were protected when compared to non-immunized controls, immunization with OV-HA-NP resulted in incremental protection against challenge infection as evidenced by a reduced secondary antibody response (NA and HI antibodies) following IAV-S challenge and reduced virus shedding in nasal secretions (lower viral RNA loads and frequency of animals shedding viral RNA and infectious virus), when compared to animals in the OV-HA group. Interestingly, broader cross neutralization activity was also observed in serum of OV-HA-NP-immunized animals against a panel of contemporary IAV-S isolates representing the major genetic clades circulating in swine. This study demonstrates the potential of ORFV-based vector for control of swine influenza virus in swine.

scholarly journals Can diffusion and T2 star-weighted magnetic resonance imaging aid in the diagnosis of ectopic endometrium?

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Mariam Raafat ◽  
Soha H. Talaat ◽  
Salma M. Abdelghaffar ◽  
Engy A. Ali
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Statistical Significance ◽  
P Value ◽  
Large Sample Size ◽  
Resonance Imaging ◽  
Conventional Mri ◽  
Patient Will ◽  
Magnetic Resonance Imaging Mri ◽  
Ectopic Endometrium

Abstract Background Endometriosis is a common gynecologic disorder characterized by the implantation of the endometrial tissue ectopically outside the endometrial cavity. It affects about 10% of females at the childbearing period and is estimated to be present up to 20–50% in women complaining of infertility. While laparoscopy is considered the mainstay for diagnosis, magnetic resonance imaging (MRI) is recognized as a useful tool for definitive diagnosis, pre-surgical planning, and determining whether the patient will require multi-specialty involvement. The aim of this study is to evaluate the performance of MRI with the addition of diffusion-weighted imaging (DWI) and T2 star (T2*) to conventional MRI, for the accurate assessment of ectopic endometrium. Results Endometriotic lesions that showed diffusion restriction on DWI were 80.7%, and 96.1% of the endometriotic lesions had signal voids on the T2*W sequence, whereas only 65.4% of the lesions had typical signal intensities on T1WI and T2WI. Diagnostic performance of the MRI examination was improved by the use of the diffusion sequence and better improved by the T2* sequence, compared to the conventional MR protocol sensitivity (SE) = 96.12% and specificity (SP) = 85.7% in T2*-weighted images, SE = 80.7% and SP = 71.4% in DWI, and SE = 65.4% and SP = 71.4% in conventional MRI. P value for conventional MRI was 0.1, which is of no statistical significance (p < 0.05). P value for DWI was 0.016, which is statistically significant (p < 0.05). P value for T2*WI was 0.001, which is more statistically significant (p < 0.05) and could be adequately correlated with laparoscopy. Conclusion DWI and T2* significantly increase MRI diagnostic accuracy by allowing the detection of the hemorrhagic character of the endometriotic lesions. Studies with a large sample size are needed to confirm that they can replace invasive laparoscopy for the diagnosis of endometriosis.

scholarly journals Aerosol Infection of BALB/c Mice with Brucella melitensis and Brucella abortus and Protective Efficacy against Aerosol Challenge

2007 ◽  
Vol 75 (10) ◽  
pp. 4923-4932 ◽  
Author(s):  
M. M. Kahl-McDonagh ◽  
A. M. Arenas-Gamboa ◽  
T. A. Ficht
Keyword(s):  
Lung Tissue ◽  
Brucella Abortus ◽  
Brucella Melitensis ◽  
Protective Efficacy ◽  
Human Infection ◽  
Challenge Infection ◽  
Worldwide Distribution ◽  
Aerosol Exposure ◽  
Aerosol Chamber ◽  
Aerosol Infection

ABSTRACT Brucellosis is a zoonotic disease with a worldwide distribution that can be transmitted via intentional or accidental aerosol exposure. In order to engineer superior vaccine strains against Brucella species for use in animals as well as in humans, the possibility of challenge infection via aerosol needs to be considered to properly evaluate vaccine efficacy. In this study, we assessed the use of an aerosol chamber to infect deep lung tissue of mice to elicit systemic infections with either Brucella abortus or B. melitensis at various doses. The results reveal that B. abortus causes a chronic infection of lung tissue in BALB/c mice and peripheral organs at low doses. In contrast, B. melitensis infection diminishes more rapidly, and higher infectious doses are required to obtain infection rates in animals similar to those of B. abortus. Whether this difference translates to severity of human infection remains to be elucidated. Despite these differences, unmarked deletion mutants BAΔasp24 and BMΔasp24 consistently confer superior protection to mice against homologous and heterologous aerosol challenge infection and should be considered viable candidates as vaccine strains against brucellosis.

scholarly journals Reproduction of Fowl Typhoid by Respiratory Challenge with Salmonella Gallinarum

2008 ◽  
Vol 52 (1) ◽  
pp. 156-159 ◽  
Author(s):  
Hom Bahadur Basnet ◽  
Hyuk-Joon Kwon ◽  
Sun-Hee Cho ◽  
Sun-Joong Kim ◽  
Han-Sang Yoo ◽  
...  
Keyword(s):  
Salmonella Gallinarum ◽  
Fowl Typhoid ◽  
Respiratory Challenge
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