Six clinical cases of avipoxvirus (APV) infection were investigated and molecular biologically studied. The samples were collected from different domesticated birds reared in the Egyptian backyard management system and were propagated on the chorioallantoic membrane of embryonated chicken eggs. The virus isolation was confirmed via PCR amplification of fpv167 (P4b) gene locus. All the studied isolates were characterized as Fowlpox-like viruses based on the amplicon length of fpv140 gene locus. The phylogenetic analysis of fpv167 (P4b) gene clustered Elsharqyia_FWPV1, Elsharqyia_FWPV2, Elsharqyia_FWPV3, Elsharqyia_FWPV4, and Elsharqyia_TKPV strains within subclade A1. Furthermore, Elsharqyia_PGPV strain was clustered within subclade A2 (Turkeypox virus) and showed 100 % nucleic acid identity with the wood pigeon Indian which was isolated in 2009. On the other hand, when the fpv140 gene was used for the phylogenetic analysis, Elsharqyia_PGPV was clustered within subclade A4 (Pigeonpox virus) with the other PGPVs. This study is considered the first molecular record for APVs circulating in the Egyptian birds. Further studies in a larger scale need to be developed to have a better understanding about the molecular characterization of the Egyptian APV strains.

In spite of the intensive vaccination policy against the Marek's disease virus (MDV) in Egypt, the Egyptian poultry flocks are still suffering from several tumor and paralysis cases. To investigate if MDV is the possible cause, feather follicle and tumor samples were collected during 2011 from 30 vaccinated chicken flocks experiencing nervous signs, emaciation, and tumor lesions. The samples were screened by PCR amplification of the meq full-length gene. Only five of 30 flocks were positive for MDV. Additionally, we sequenced meq from five samples and gL and gC from three samples. A phylogenetic tree was constructed using the deduced amino acid sequences of the meq gene. The sequence analysis revealed that most of the studied sequences showed > or = 98% identity to the very virulent European ATE and C12/130 isolates and the very virulent Chinese LMS, YA, WS03, and GX070060 MDV isolates. The two glycoproteins, gL and gC, displayed high similarity to the classical MDV strains published in the database regardless of their virulence.

Florfenicol (FFC) as a chloramphenicol's derivative is a special broad-spectrum antibiotic that was used in veterinary clinics. In the present study, we investigated the effect of different doses of FFC on the humoral immune response of broiler chickens to Newcastle disease virus (NDV) vaccine under the impact of E. coli infection. In addition, the expression of the interferon-inducible genes (IRF7, 2'-5'OAS and Mx1) were analyzed in the spleen tissue of these chickens using quantitative real-time PCR (qRT-PCR). The non-treated group with FFC and non-infected with E. coli had the highest immune responses against NDV compared with the FFC treated groups. In the case of E. coli infection, the group treated with FFC (30 mg/Kg BWt) showed lower NDV HI and IgG ELISA Ab levels compared to the group treated with FFC (60 mg/Kg BWt). A dose dependent up-regulation was observed in the level of the interferon-alpha pathway related genes (IRF7 and 2'-5'OAS) in the FFC treated groups compared to the non-treated group. At the slaughter time, the numbers of adipocyte in the bone marrow were significantly higher with moderate atrophy of the hematopoietic lineages in the FFC treated birds compared to the non-treated birds. These results indicated that this FFC dosage dependent increase in the humoral immune responses against NDV vaccine could be attributed to its efficient therapeutic effect on the E. coli infection. However, the increase in the FFC dosage can negatively but temporarily affect the chicken body weights. Additionally, it can exert up regulation effect on the chicken innate immune response with moderate hypoplasia of the bone marrow cells.

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| Supplementation of the herbal oils in poultry nutrition is considered an alternative and complementary approach to the conventional control viral strategies in poultry industry. Their use is associated with remarkable improvement in both bird performance and immunity. In the current study, one hundred twenty broiler chickens were allocated into four equal groups. Three groups (group B, C and D) were vaccinated with inactivated avian influenza and live LaSota vaccine and one group (group A) was left as a control non vaccinated group. Two groups, C and D, were orally treated with 0.005 and 0.01% Oregano essential oil (OEO) respectively. Oral supplementation with a higher dose exerts improvement in the bird performance parameters in the early period of bird life and up to 21 days of age. Positive regulation of both NDV and AIV-HI specific antibody titers was existed when the birds were supplemented with the oil together with both NDV and AI vaccination, especially in case of the higher dose. Study of the effect of the OEO on chicken interferon-alpha signalling pathway components post NDV vaccination using quantitative real-time PCR (qRT-PCR) revealed no obvious positive immunomodulatory effect on Myxovirus resistance 1 (Mx1) transcripts level except at 29 days of age. On the other hand, a dose dependent up-regulation in both IFN regulatory factor 7 (IRF-7) and interferon-alpha RNA levels was observed. Both doses of OEO could protect the birds from nervous manifestation resulting from challenge with vvNDV. In conclusion, oral supplementation with OEO has beneficial effects on bird performance as well as humoral and innate immune responses.

Newcastle Disease Virus (NDV) genotype VII is a highly pathogenic Orthoavulavirus that has caused multiple outbreaks among poultry in Egypt since 2011. This study aimed to observe the prevalence and genetic diversity of NDV prevailing in domestic and wild birds in Egyptian governorates. A total of 37 oropharyngeal swabs from wild birds and 101 swabs from domestic bird flocks including chickens, ducks, turkeys, and pelicans, were collected from different geographic regions within 13 governorates during 2019–2020. Virus isolation and propagation via embryonated eggs revealed 91 swab samples produced allantoic fluid containing haemagglutination activity, suggestive of virus presence. The use of RT-PCR targeted to the F gene successfully detected NDV in 85 samples. The geographical prevalence of NDV was isolated in 12 governorates in domestic birds, migratory, and non-migratory wild birds. Following whole genome sequencing, we assembled six NDV genome sequences (70–99% of genome coverage), including five full F gene sequences. All NDV strains carried high virulence, with phylogenetic analysis revealing that the strains belonged to class II within genotype VII.1.1. The genetically similar yet geographically distinct virulent NDV isolates in poultry and a wild bird may allude to an external role contributing to the dissemination of NDV in poultry populations across Egypt. One such contribution may be the migratory behaviour of wild birds; however further investigation must be implemented to support the findings of this study. Additionally, continued genomic surveillance in both wild birds and poultry would be necessary for monitoring NDV dissemination and genetic diversification across Egypt, with the aim of controlling the disease and protecting poultry production.

Fowl pox disease is a slow-spreading viral infection of wild and domesticated birds of both genders, all ages and breeds. The disease occurs in two distinct forms; the more common cutaneous or dry form and the less common diphtheritic form. Fowl poxvirus (FWPV) is a member of the Avipoxvirus (APV) and it is one of the greatest challenges facing the poultry industry, its incidence is higher in tropical and subtropical countries. It causes a significant level of morbidity and increased mortality, especially in the diphtheritic form which may reach to 50%. Avipoxvirus has been recorded in Egypt and Africa in the early of 1960, since then, it has been recorded in variable domesticated and wild bird species in different countries and Governorates. The free-living and wild birds represent a potential threat and source of infection for the domesticated poultry species. In the last ten years, the phylogenetic analysis of the partial genome sequences has gained insight into the evolutionary biology of APV in Africa. One of the main characters of APV is relative genetic stability, especially in fpv167 region of the genome. This area of the genome clustered the APV of chicken and turkey origin phylogenetically into fowl poxvirus subclade A1 together with other avipoxviruses (APVs) isolated from Galliformes worldwide. However, the pigeon poxviruses phylogenetically belong to subclade A2 with other APVs isolated from Columbiformes worldwide. The analysis of the fpv140 region provides a further comprehensive taxonomic classification based on the virus-host origin and distribution, especially in the case of the pigeon poxvirus (PGPV), which clustered separately into different subclades according to their geographical distribution. This review focus on the origin, distribution, classification and taxonomy of APVs circulating in Egypt mainly with a brief report on the situation of APVs in the other neighboring.

Ornithobacterium rhinotracheale is a Gram-negative bacterium associated with respiratory diseases in many avian species and it causes variable economic losses to the poultry industry. In this study, single aerosol infection of broiler chickens with three PCR confirmed local isolates of Ornithobacterium rhinotracheale (ORT) from Sharkia Governorate was found to cause growth retardation together with mild respiratory manifestations and 5-10% mortalities. Mild tracheitis, airsacculitis and pneumonia were observed post aerosol administration. Co-infection with E. coli was found to have triggered effect on ORT infection in broiler and cause a higher degree of pathogenicity, higher mortalities and severe growth retardation than the single infection. The three different isolates were found to cause nearly the same degree of inflammatory response. ORT infection alone resulted in minimal microscopic lesions in the trachea and air sacs. Mixed infection (ORT with E. coli) resulted in more severe lesions than those by ORT alone as well as dense lymphocytic infiltrations in tracheas, lungs, air sacs and hearts were shown. Amoxicillin was successfully improving the clinical signs and body weight gain of ORT infected birds.