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Fifty broiler chicks were divided into five groups to study the antiviral and immune-stimulant effect of Allium cepa essential oils (ACEO). The effect of Allium cepa essential oils administration single or combined with NVD vaccine in broilers, more than one parameter was studied in this study i.e., the clinical symptoms that appeared on the chicks after the experimental infection with velogenic Newcastle disease virus, postmortem lesions, pathological lesions scoring, mortality rate (MR), and viral shedding, birds immunity was assessed by HI test and protection percent post-challenge with vNDV. Our result showed that mild clinical signs, lesion scoring, decreased viral shedding in ACEO treated groups 3 (G 3) more than control groups post-challenge with vNDV. Delayed onset of mild clinical signs in G3 followed by complete recovery 7th-day post-challenge (DPC). Low MR (40 and 0%) and high protection percent (100 and 60%) in ACEO treated G3 and G5, respectively. spleen, thymus, cecal tonsil, proventriculus, and cerebrum lesions scoring in G3 and G5 were significantly ((p ≤ 0.05).) lower than the control group, proving a decrease in NDV replication and effective antiviral activity of ACEO. HI titer significantly increased (p ≤ 0.05) In G3, G4 and G5 compared with control groups. There is no significant difference in HI titer in ACEO treated groups and vaccinated groups. In conclusion, oral administration of ACEO combined with NDV vaccines significantly reduces or eliminates lethal clinical signs, lesions, viral shedding, and enhances immune response and protection percent after vNDV challenge proving the natural antiviral and immune stimulant effect of ACEO onion extract. Implementing such a regime might aid NDV control in broiler flocks in endemic areas and reduce the epidemiological load of NDV in the environment.

The present study involved in vivo evaluation of the growth promoting effects of thymol and thymol nanoemulsion and their protection against Salmonella Typhimurium infection in broilers. One-day old 2400 chicks were randomly divided into eight groups; negative and positive control groups fed basal diet without additives and thymol and thymol nanoemulsion groups (0.25, 0.5 and 1% each). At d 23, all chicks except negative control were challenged with S. Typhimurium. Over the total growing period, birds fed 1% thymol nanoemulsion showed better growth performance even after S. Typhimurium challenge, which came parallel with upregulation of digestive enzyme genes (AMY2A, PNLIP and CCK). Additionally, higher levels of thymol nanoemulsion upregulated the expression of MUC-2, FABP2, IL-10, IgA and tight junction proteins genes and downregulated IL-2 and IL-6 genes expression. Moreover, 1% thymol nanoemulsion, and to lesser extent 0.5% thymol nanoemulsion and 1% thymol, corrected the histological alterations of cecum and liver postinfection. Finally, supplementation of 1% thymol, 0.5 and 1% thymol nanoemulsion led to increased Lactobacilli counts and decreased S. Typhimurium populations and downregulated invA gene expression postinfection. This first report of supplying thymol nanoemulsion in broiler diets proved that 1% nano-thymol is a potential growth promoting and antibacterial agent.

Aim: The present study was designed for the detection of the most prevalent respiratory infections in chicken flocks and clarifying their interaction and impact on flock health. Materials and Methods: A total of 359 serum samples were collected from 55 backyard chickens and tested using commercial enzyme-linked immunosorbent assay kits to determine the seroprevalence of Newcastle disease virus (NDV), infectious bronchitis virus (IBV), influenza type A, Mycoplasma gallisepticum (MG), and Mycoplasma synoviae (MS). Molecular prevalence of NDV, IBV, low pathogenic avian influenza virus (LPAIV) H9N2, MG, and MS was carried out on swab, and tissue samples collected from 55 backyard flocks and 11 commercial broiler flocks suffered from respiratory infections using polymerase chain reaction (PCR) and reverse transcription-PCR. Results: Seroprevalence of NDV, IBV, Influenza type A virus, MG, and MS in chicken backyard flocks was 56.4%, 50.9%, 12.7%, 14.5%, and 3.6%, respectively. Specific antibodies against one or more respiratory viruses and mycoplasma were detected in 36.4% of backyard flocks, indicating concurrent viral infections. The molecular survey showed that 90.9% of chicken backyard flocks were infected with common respiratory viruses (NDV, IBV, and LPAIV H9N2) while 81.8% of commercial broiler flocks were infected. The molecular prevalence rate of NDV, IBV, and LPAIV H9N2 was 46.97%, 56.1%, and 19.7% in backyard flocks, respectively. Combined viral and bacterial infection represented 40% and 63.6% of the respiratory infections, resulting in enhanced pathogenicity and increased mortalities of up to 87.5% and 27.8% in backyard and commercial flocks, respectively. Mixed infection of IBV, LPAIV H9N2, and/or Escherichia coli is the most prevalent mixed infection in broiler flocks, inducing severe clinical outcomes. Avian pathogenic E. coli was, respectively, isolated from 40% of backyard flocks and 81.82% of broiler flocks. Staphylococcus aureus was isolated from three backyard chicken flocks mixed with other respiratory pathogens with elevated mortality. Mixed infection of E. coli and MG reported in 9.1% of broiler flock. MG was detected in 14.5% of backyard flocks and 9.1% of broiler flocks while MS was detected only in 3.6% of backyard chickens mixed with E. coli, and other viruses. Conclusion: Our results confirm that mixed infections are more commonly prevalent and associated with dramatic exacerbation in clinical outcomes than a single infection. Bidirectional synergistic interaction between these concurrently interacted respiratory pathogens explains the severe clinical impact and high mortality rate. The high prevalence of IBV (either as a single or combined infection) with LPAIV H9N2 and/or E. coli, in spite of intensive use of commercial vaccines, increases the need for revising vaccination programs and the application of standard biosecurity measures. Backyard chickens impose a great risk and threaten commercial flocks due to the high prevalence of viral respiratory pathogens.

Among many avian mycoplasmas, Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS) are recognized as the main etiological agents of respiratory diseases and infectious synovitis in chickens and turkeys causing tremendous economic losses worldwide. Therefore, proper treatment is promoted for the control of these diseases. This study was the first in Egypt to evaluate the in vitro efficacy of various antimicrobials against field MG and MS isolates recovered from chicken and turkey flocks using both conventional broth microdilution and quantitative real-time polymerase chain reaction assays. Totally, 47 mycoplasma isolates were recovered from 160 collected tracheal samples (29.4%). Of these, 44 MG (27.5%) and 3 MS (1.9%) were identified using conventional and molecular assays. The in vitro susceptibilities of 4 representative mycoplasma field isolates (3 MG and one MS) to 8 antibiotics and 4 essential oils were investigated. The tested isolates showed various susceptibilities to tested antimicrobials. Toldin CRD, followed by clove, cumin, and cinnamon oils were effective against both MG and MS clinical isolates with minimum inhibitory concentration (MIC) values ranging from 0.49 to 15.63 µg/mL. Similarly, tylvalosin was the most active antibiotic against MG and MS isolates with the lowest MIC values (0.015 to 0.03 µg/mL). DNA loads of both MG mgc2 and MS vlhA genes were markedly decreased upon treatment with majority of the tested antimicrobials confirming their effectiveness as was also evaluated by conventional MIC results. In conclusion, Toldin CRD and tylvalosin were found to be the most effective antimicrobials in this study. This finding highlights the importance of using these antimicrobials in controlling mycoplasma infections in chickens and turkeys.

Fifty broiler chicks were divided into five groups to study the antiviral and immune-stimulant effect of

Among many avian mycoplasmas,Mycoplasma gallisepticum(MG) andMycoplasma synoviae(MS) are recognized as the main etiological agents of respiratory diseases and infectious synovitis in chickens and turkeys causing tremendous economic losses worldwide. Therefore, proper treatment is promoted for the control of these diseases. This study was the first in Egypt to evaluate thein vitroefficacy of various antimicrobials against field MG and MS isolates recovered from chicken and turkey flocks using both conventional microdilution and quantitative real-time PCR (qRT-PCR) assays. Totally, 47 mycoplasma isolates were recovered from 160 collected tracheal samples (29.4%). Of these, 44 MG (27.5%) and 3 MS (1.9%) were identified using conventional and molecular assays. Thein vitrosusceptibilities of 4 representative mycoplasma isolates (3 MG and one MS) to 8 antibiotics and 4 essential oils were investigated. The tested isolates showed various susceptibilities to tested antimicrobials. Toldin CRD, followed by clove, cumin and cinnamon oils were commonly effective against both MG and MS clinical isolates with MIC values ranging from 0.49 to 15.63 µg/mL. Similarly, tylvalosin was the most active antibiotic against MG and MS isolates with the lowest MIC values (0.015-0.03 µg/mL). DNA copies of both MGmgc2and MSvlhAgenes were markedly decreased upon treatment with majority of tested antimicrobials confirming their effectiveness as was also evaluated by conventional MIC results. In conclusion, Toldin CRD and tylvalosin were found to be the most effective antimicrobials in this study, which will contribute in controlling avian mycoplasma infections.Author SummaryAvian mycoplasmosis is considered as one of the most prominent economic problems in the commercial poultry industry worldwide. Antimicrobial therapy is the most effective tool for treatment of mycoplasmas. Owing to the side effects of antibiotics and the development of resistance to the currently used drugs, an increased emphasis on the use of alternative antimicrobials is of utmost importance. Here, we evaluate thein vitroinhibitory effects of some essential oils and various commercial antibiotics againstMycoplasma gallisepticum(MG) andMycoplasma synoviae(MS) field isolates using micro-broth dilution method and qRT-PCR assays. We found that toldin CRD, followed by clove, cumin and cinnamon oils were effective against both MG and MS clinical isolates. Similarly, tylvalosin was the most active antibiotic against MG and MS isolates. We also found that DNA copies of both MGmgc2and MSvlhAgenes were markedly decreased upon treatment with majority of tested antimicrobials. Our study provides new insights into the control of avian mycoplasma infections.

Newcastle disease (ND) is a highly devastating disease for the poultry industry as it causes high economic losses. In this present study, a DNA vaccine containing the F and HN surface antigens of a highly virulent Newcastle disease virus (NDV), NDV/1/Chicken/2005 (FJ939313), was successfully generated. Cell transfection test indicated that the vaccine expressed the F and HN genes in Hep-2 cells. The main objective of this study was to compare the extent of protection induced by DNA vaccination after homologous and heterologous NDV-challenge as determined by the amount of NDV shedding after challenge. NDV-antibody-negative chickens were vaccinated either once, twice or thrice intramuscularly at 7, 14 and 21 days old and were challenged 14 days post vaccination with either homologous virus (vaccine-matched velogenic viscerotropic Newcastle disease virus (vvNDV) strain, FJ939313), phylogenetically related to group VII, or a phylogenetically divergent heterologous virus (unmatched vvNDV strain, AY968809), which belongs to genogroup VI and shows 84.1% nucleotide similarity to the NDV-sequences of the DNA vaccine. Our data indicate that birds, which received a single dose of the DNA vaccine were poorly protected, and only 30-40% of these birds survived after challenge with high virus shedding titre. Multiple administration of the DNA vaccine induced high protection rates of 70-90% with reduced virus shedding compared to the non-vaccinated and challenged birds. Generally, homologous challenge led to reduced tracheal and cloacal shedding compared to the heterologous vvNDV strain. This study provides a promising approach for the control of ND in chickens using DNA vaccines, which are phylogenetically closely related to the circulating field strains.

Infectious bursal disease virus (IBDV) is one of the most important viral pathogens of chickens. This virus causes great economic losses to the poultry industry due to factors like high mortality rates and poor growth performance of the affected chickens. Despite the intensive application of different vaccines against IBDV, several outbreaks are still emerging in many parts across the globe. This chapter highlights some important basic and clinical information related to IBDV. Further, the pathological changes and the molecular pathogenesis of IBDV infection in chicken have been discussed. In addition, recent advances on the vaccine preparation and prophylaxis against the IBDV infection have been touched. There is a need for further research to find the most appropriate vaccine and control measures against the IBDV infection in chickens.

Background Avian influenza viruses are still causing major concern not only to the poultry industry but also to human health across the globe. The live poultry markets and the small-scale local breeding of various species of birds in backyards are still playing important roles in the sustainability of most virulent influenza viruses, especially H5N8. Methods The authors investigated an outbreak of highly pathogenic avian influenza H5N8 in backyard flocks in Al Ahsa, Eastern Saudi Arabia that occurred in 2017–2018. Results A range of poultry including chickens, ostriches, ducks, pigeons and turkeys were clinically affected. Phylogenetic analysis suggested that this was a common source outbreak caused by a virus closely related to H5N8 viruses causing outbreaks elsewhere in Saudi Arabia in early 2018. Conclusions Small backyard flocks are still contributing to the epidemiology and transmission of H5N8.

During the period from 2015 to 2017, frequent outbreaks of inclusion body hepatitis (IBH) were observed in broiler chickens and falcons in Saudi Arabia. Fifty samples were collected from both species. The histopathological examination and polymerase chain reaction confirmed the IBH infection in eight samples (five samples from chickens and three samples from falcons). The genomic sequence and phylogenetic analysis based on nucleotide and amino acid sequences of Saudi strains, reference fowl aviadenoviruses (FAdVs) and field viruses available in Genbank revealed that all investigated FAdVs clustered into FAdV-2 (species D) and FAdV-6 (species E). The host-dependent characterization revealed that falcon origin strains showed low identity (∼35%) with falcon adenoviruses isolated from USA, which clustered into a separate group. The identification of FAdV-D and FAdV-E in diseased falcons and chickens indicates cross-species transmission although falcons and chickens are phylogenetically different. The control of IBH infection in falcons and chickens should be based on the separation of carriers and susceptible chickens as well as falcons to prevent cross-species contact. Vaccination is an important method for prevention of IBH. The characterization of newly emerging FAdV strains provides valuable information for the development of an efficacious control strategy based on the molecular structure of current circulating FAdV strains in different species of birds.