Diseases Of Poultry 13th Edition Pdf Free PATCHED Download
One of the major bacterial infectious diseases in the poultry industry is avian pathogenic Escherichia coli (APEC), which causes colibacillosis in chickens. To develop a novel nucleic acid-free bacterial ghost (BG) vaccine against the O78:K80 serotype of APEC, in this study we constructed a plasmid that harbored E-lysis and S nuclease (SNUC). Following the expression, the O78:K80 bacteria lost all of their cytoplasmic content and nucleic acids by enzymatic digestion. The functionality of these two proteins in the production procedure of bacterial ghosts was confirmed by monitoring the number of colonies, scanning electron microscopy imaging, gel electrophoresis of genomic DNA, and qPCR on the plasmid content of bacterial ghosts. The protective efficacy of the ghost vaccine generated from O78:K80 serotype of APEC was tested in chickens by injection and inhalation routes and compared with that in chickens that received the injection of a killed vaccine. The O78:K80 BG vaccine candidate, used as injection and inhalation, in comparison with the killed vaccine, triggered higher proinflammatory cytokine expression including IL-6, IL-1β, and TNFSF15; a higher level of antibody-dependent humoral (IgY and IgA) and cellular immune responses (IFNγ and lymphocyte proliferation); and lower lesion scores. According to the results of this study, we suggest that the bacterial ghost technology has the potential to be applied for the development of novel vaccines against avian colibacillosis. This technology provides an effective and reliable approach to make multivalent vaccines for more prevalent APEC strains involved in the establishment of this infectious disease in the poultry industry.
diseases of poultry 13th edition pdf free download
Despite all these remarkable advantages and benefits of BGs, there is a concern about the possibility of the presence of viable and reproductive bacterial cells at the end of the BG production process [17, 25]. To guarantee the total inactivation of target bacteria in BG preparation, the expression of a secondary lethal gene has been applied. For this purpose, the intracellular expression of staphylococcal nuclease (SNUC) without the signal sequences for extracellular release has been used [17, 26]. The expression of this enzyme at the presence of Ca2+ and Mg2+ resulted in cleaving either single- or double-stranded DNA or RNA to mono, di, or oligonucleotides. This intracellular degradation restricts or abolishes the reproductive cells in lysis media [17, 25]. Importantly, the generation of the nucleic acid-free version of BGs eliminates the risk of antibiotic resistance gene transfer to hosts. Due to the presence of E-lysis and SNUC genes and also all the mentioned properties and advantages, BGs turn out to be a desired therapeutic agent, which is especially applicable for gram-negative bacterial diseases [17, 25, 26].
In this study, we have designed and developed a candidate nucleic-acid free bacterial ghost vaccine against APEC, O78:K80 serotype. Vaccination plays an important role in the health management of the poultry industry . There are numerous bacterial infectious diseases, such as APEC causing colibacillosis, which could be prevented by vaccination. An ideal vaccine for APEC has to overcome several challenges, for example, to induce cross-protection against various APEC serogroups involved in the disease; could be deliverable through a mass immunization method such as through the drinking water or feed, in ovo, and spraying; and finally could be administered to young-aged chickens to develop a whole protective immunity before day 21 when they are most susceptible to APEC [2, 12].
Japanese quails (Coturnix coturnix japonica) have been reported to be affected by several infectious and non-infectious poultry diseases . Avian influenza virus (AIV) H9N2 is one of the most common poultry diseases, and the epidemics of this virus have been recorded . This virus subtype is a low pathogenic avian influenza virus (LPAIV), and it infects poultry species such as Japanese quails and evidence for antigenic diversity of H9N2 viruses isolated from quails was shown . Peacock et al.  reviewed global distribution of H9N2 in poultry including quails. Incomplete protection of the inactivated vaccine against AIV in quails was indicated post-challenge with a field isolate of AIV H9N2, which could infect 30 to 40% of the vaccinated birds. Vaccination of quails with H9N2 induced high antibody titers and the inactivated vaccine did not fully prevent the infection .