Protective Efficacy of a Commercial Live Attenuated aroA mutant Vaccine Against Avian Pathogenic Escherichia coli Challenge in Broilers

Gharib, Ahlam A.; Hamouda, Ahmed; bdel-Wahab, Ashraf A A.M.; Fawzy, Mohammed

doi:10.21608/zvjz.2017.7867

Cited by 4 publications

(4 citation statements)

References 21 publications

(37 reference statements)

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“…Additionally, clinical and lesion scores were higher compared to the negative control groups. The performance parameters and the detection of APEC O 125 challenge strain in both vaccinated challenged and challenge control groups were almost the same [ 28 ]. These results indicate the failure of the attenuated E. coli derivatives (deleted gene mutants) to protect against heterologous challenge [ 24 , 29 ] confirming Kariyawasam and co-workers’ finding that the protection conferred by mutant E. coli vaccine is serogroup specific [ 30 ].…”

Section: Discussionmentioning

confidence: 99%

Efficacy of Live Attenuated Vaccine and Commercially Available Lectin against Avian Pathogenic E. coli Infection in Broiler Chickens

El-Mawgoud¹,

El-Nahass

Shany

et al. 2020

Veterinary Sciences

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In this study, the protective efficacy of an E. coli live attenuated vaccine was compared to the preventive administration of lectin preparation before the challenge. Two hundred broiler chicks were divided into eight equal groups. The first group was used as a negative control group. Three groups were vaccinated at day 1 with the avian colibacillosis live vaccine of which one group served as a vaccinated nonchallenged group. Another two groups were treated with lectin product (0.5 mL/L drinking water) for three days before the challenge. The last two groups served as challenge control for either E. coli O78 or O125 strains. The challenge was conducted at three weeks of age with either homologous O78 or heterologous O125 E. coli strains, using 0.5 mL/bird of each avian pathogenic E. coli (APEC) strain (~108 colony forming units “CFU”/mL)/subcutaneously. The bodyweight and feed conversion ratios (FCR) were calculated for four weeks. Clinical signs and gross and histopathological lesions were scored at two and seven days post inoculation (dpi). The heart and liver of euthanized chickens at 2 dpi were removed aseptically and homogenized to evaluate pathogenic E. coli colonization. Results showed that live avian colibacillosis vaccine reduced mortalities and APEC colonization in the homologous challenge group but not in the heterologous challenge group. Lectin-treated groups showed 20% and 16% mortality after challenge with E. coli O78 and O125, respectively, and both groups showed performance parameters, clinical signs, and histopathological lesion scores comparable to the negative control group, with variable E. coli colonization of heart and liver. The study demonstrated the efficacy of live attenuated avian colibacillosis vaccine against homologous but not heterologous APEC challenge in broiler chickens. The lectin-containing products can be used as a preventive medication to reduce the clinical impacts of colibacillosis regardless of the challenge strain. Standardization of the evaluation parameters for APEC vaccines is recommended.

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Section: Discussionmentioning

confidence: 99%

Efficacy of Live Attenuated Vaccine and Commercially Available Lectin against Avian Pathogenic E. coli Infection in Broiler Chickens

El-Mawgoud¹,

El-Nahass

Shany

et al. 2020

Veterinary Sciences

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“…Unlike young chickens in which immunity largely depends on activity of the innate immune system as well as on maternal antibodies, in adult birds the adaptive immune system is fully developed and functional T and B cell responses can be expected ( 24 ). Although, the development and role of immune cells regarding an APEC infection in chicken is highlighted ( 25 ) little has been published explaining the dynamics of the immune system of E. coli infected chickens using flow cytometry on samples of circulating cells such as monocytes/macrophages, CD4 + or CD8 + cells ( 17 , 26 , 27 ). Recently, investigations on cytokine production of T cells after ex vivo re-stimulation revealed significantly elevated levels of APEC-specific IFN-γ-producing CD8α, CD4, TCR-γδ cells in lung, spleen and blood mononuclear cells of naïve specific pathogen-free (SPF) chickens ( 28 ).…”

Section: Introductionmentioning

confidence: 99%

Aerosol vaccination of chicken pullets with irradiated avian pathogenic Escherichia coli induces a local immunostimulatory effect

Bagheri,

Mitra,

Paudel

et al. 2023

Front. Immunol.

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The present study investigated the expression of cytokines and cellular changes in chickens following vaccination with irradiated avian pathogenic Escherichia coli (APEC) and/or challenge. Four groups of 11-week-old pullets, each consisting of 16 birds were kept separately in isolators before they were sham inoculated (N), challenged only (C), vaccinated (V) or vaccinated and challenged (V+C). Vaccination was performed using irradiated APEC applied via aerosol. For challenge, the homologous strain was administered intratracheally. Birds were sacrificed on 3, 7, 14 and 21 days post challenge (dpc) to examine lesions, organ to body weight ratios and bacterial colonization. Lung and spleen were sampled for investigating gene expression of cytokines mediating inflammation by RT-qPCR and changes in the phenotype of subsets of mononuclear cells by flow cytometry. After re-stimulation of immune cells by co-cultivation with the pathogen, APEC-specific IFN-γ producing cells were determined. Challenged only birds showed more severe pathological and histopathological lesions, a higher probability of bacterial re-isolation and higher organ to body weight ratios compared to vaccinated and challenged birds. In the lung, an upregulation of IL-1β and IL-6 following vaccination and/or challenge at 3 dpc was observed, whereas in the spleen IL-1β was elevated. Changes were observed in macrophages and TCR-γδ+ cells within 7 dpc in spleen and lung of challenged birds. Furthermore, an increase of CD4+ cells in spleen and a rise of Bu-1+ cells in lung were present in vaccinated and challenged birds at 3 dpc. APEC re-stimulated lung and spleen mononuclear cells from only challenged pullets showed a significant increase of IFN-γ+CD8α+ and IFN-γ+TCR-γδ+ cells. Vaccinated and challenged chickens responded with a significant increase of IFN-γ+CD8α+ T cells in the lung and IFN-γ+TCR-γδ+ cells in the spleen. Re-stimulation of lung mononuclear cells from vaccinated birds resulted in a significant increase of both IFN-γ+CD8α+ and IFN-γ+TCR-γδ+ cells. In conclusion, vaccination with irradiated APEC caused enhanced pro-inflammatory response as well as the production of APEC-specific IFN-γ-producing γδ and CD8α T cells, which underlines the immunostimulatory effect of the vaccine in the lung. Hence, our study provides insights into the underlying immune mechanisms that account for the defense against APEC.

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“…In a field trial, the Poulvac vaccine did not affect the weight gain in broiler chickens [54]. In experimental conditions, several studies have suggested its efficacy against homologous challenge in reducing colibacillosis-associated pathological lesions [54][55][56][57][58]. Oral vaccination of birds at day 5 of age reduced morbidity [59] but drinking water application was found to be ineffective in inducing protection [56].…”

Section: Live and Live Attenuated Vaccinesmentioning

confidence: 99%

“…Oral vaccination of birds at day 5 of age reduced morbidity [59] but drinking water application was found to be ineffective in inducing protection [56]. The findings regarding heterologous protection were not consistent among studies with some showing effectiveness against certain strains [54,60], but not others [56,57,60]. The efficacy of the vaccine against homologous challenge was enhanced by supplementation of probiotics Enterococcus faecalis [58] and pre-treatment with Lincospectin improved the vaccine's response [61].…”

Section: Live and Live Attenuated Vaccinesmentioning

confidence: 99%

A systematic review and meta-analysis on the efficacy of vaccination against colibacillosis in broiler production

Paudel,

Apostolakos,

Vougat Ngom

et al. 2024

PLoS ONE

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Colibacillosis, a disease caused by Escherichia coli in broiler chickens has serious implications on food safety, security, and economic sustainability. Antibiotics are required for treating the disease, while vaccination and biosecurity are used for its prevention. This systematic review and meta-analysis, conducted under the COST Action CA18217—European Network for Optimization of Veterinary Antimicrobial Treatment (ENOVAT), aimed to assess the efficacy of E. coli vaccination in broiler production and provide evidence-based recommendations. A comprehensive search of bibliographic databases, including, PubMed, CAB Abstracts, Web of Science and Agricola, yielded 2,722 articles. Following a defined protocol, 39 studies were selected for data extraction. Most of the studies were experimental infection trials, with only three field studies identified, underscoring the need for more field-based research. The selected studies reported various types of vaccines, including killed (n = 5), subunit (n = 8), outer membrane vesicles/protein-based (n = 4), live/live-attenuated (n = 16), and CpG oligodeoxynucleotides (ODN) (n = 6) vaccines. The risk of bias assessment revealed that a significant proportion of studies reporting mortality (92.3%) or feed conversion ratio (94.8%) as outcomes, had “unclear” regarding bias. The meta-analysis, focused on live-attenuated and CpG ODN vaccines, demonstrated a significant trend favoring both vaccination types in reducing mortality. However, the review also highlighted the challenges in reproducing colibacillosis in experimental setups, due to considerable variation in challenge models involving different routes of infection, predisposing factors, and challenge doses. This highlights the need for standardizing the challenge model to facilitate comparisons between studies and ensure consistent evaluation of vaccine candidates. While progress has been made in the development of E. coli vaccines for broilers, further research is needed to address concerns such as limited heterologous protection, practicability for application, evaluation of efficacy in field conditions and adoption of novel approaches.

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Protective Efficacy of a Commercial Live Attenuated aroA mutant Vaccine Against Avian Pathogenic Escherichia coli Challenge in Broilers

Cited by 4 publications

References 21 publications

Efficacy of Live Attenuated Vaccine and Commercially Available Lectin against Avian Pathogenic E. coli Infection in Broiler Chickens

Efficacy of Live Attenuated Vaccine and Commercially Available Lectin against Avian Pathogenic E. coli Infection in Broiler Chickens

Aerosol vaccination of chicken pullets with irradiated avian pathogenic Escherichia coli induces a local immunostimulatory effect

A systematic review and meta-analysis on the efficacy of vaccination against colibacillosis in broiler production

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