Infectious bronchitis virus (IBV) affects both vaccinated and unvaccinated flocks worldwide, with a significant impact on the poultry industry. The aim of the present study is to characterize an emerging variant pathogenic IBV originating from field outbreaks in vaccinated Egyptian layer flock. Samples were collected from disease-suspected flock with a history of administration of live and inactivated IBV vaccines (Ma5 type). Virus propagation in embryonated chicken eggs (ECEs), after three successive passages, revealed typical IBV lesions such as curling and dwarfism. The reported isolate was identified by a real-time reverse transcriptase PCR assay targeting nucleocapsid (N) gene and, further characterized by full-length spike (S1) gene sequencing. Phylogenetic analysis revealed clustering of the isolated virus within 4/91 genotype of GI-13 lineage. Deduced amino acid sequences identity revealed 75-76% and 88-90% similarity with the currently used classic (H120, Ma5, and M41) and variant vaccine strains (4/91 and CR88) in Egypt, respectively. Recombination analysis gave an evidence for distinct patterns of origin for the studied isolate providing another example of intra-genotypic recombination among IBVs and the first example of recombination within the GI-13 lineage in the Egyptian field. The studied isolate (IBV/CK/EG/ Fadllah-10/2019) emerged as a result of recombination between the variant group (Egy/var I genotype, GI-23 lineage) as a major parent and the CR88 variant vaccine strain (4/91 genotype, GI-13 lineage) as minor parent. Our data suggest that both mutation and recombination may be contributing to the emergence of IBV variants which ascertain the importance of disease monitoring in vaccinated flocks as well as re-appropriation for the current vaccine strategies.

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Large-scale surveillance is crucial for understanding the evolution and the emergence of avian influenza viruses (AIVs) in endemic areas. Circulation of highly pathogenic avian influenza (HPAI) subtype H5N1 is continuously causing significant economic losses to the Egyptian poultry industry and is a threat to public health. In this report, a HPAI H5N1 strain (A/chicken/Egypt/Fadllah-7/2014) was detected from a vaccinated flock showing clinical signs of infection. Genetic characterization of the isolate indicated a high level of nucleotide identity (95-98%) with variant and classical groups of H5N1. Moreover, multiple-nucleotide and amino acid alignments revealed several prominent and characteristic substitutions in the surface glycoprotein, which may have biological relevance to the pathobiology of the virus. Phylogenetic analysis demonstrated that the reported isolate closely relates to H5N1 AIVs subclade 2.2.1.1 in spite of no reports of this subclade since 2011 from AI reported cases in Egyptian avian species. In conclusion, our results highlight the re-emergence of a novel H5N1 AIV variant subclade 2.2.1.1 that could escape immunity induced by vaccines. This discovery illustrates the importance of continuous monitoring of poultry in this country for controlling AIV including identifying sources of vaccine seed viruses.

T here is an interest to investigate the growth promoting products rather than antibiotics since their usage in animal's food have been associated with great health hazards and resistance (Roy et al., 2002). Therefore, intensive poultry industry search to minimize the microbial load associated to farms environment and final products. Broiler performance and feed conversion efficiency are closely related with the amount and type of gut microbial load, the morphological structure of the intestinal wall and the immune system response (Huyghebaert et al., 2011). Meanwhile, safe, non-therapeutic, and antimicrobial product like Organic Acid (OA) can be added to drinking water (acidifier) to achieve the optimum broiler performance (Araujo et al., 2019) and improving the water quality (Krug et al., 2012). It is well known that contaminated drinking water is a risk factor which enhance the multiplication and spreading of water borne pathogens in broiler farms (Chaveerach et al., 2004). Likewise, previous studies showed that broilers supplemented with organic acids in drinking water have intact and highest intestinal villi with deep crypt depth

Biofilm formation is a complex process, consists of a cord of molecular and physiological events that take place through several stages including adherence, formation of microcolonies, tridimensional structuring, and maturation. Biofilmacts as a reservoir not only for food production facilities but also for animal and poultry husbandry environment and considers a source of unceasing supplier of zoonotic and foodborne microorganisms infecting both hosts and consumers. Among these organisms, Campylobacter jejuni (C. jejuni) colonizes in bird hindgut with high counts. C. jejuni is widely considered as a main cause of gastroenteritis in poultry products consumers and has the ability to form biofilm on surfaces inside poultry farms and slaughterhouses or food contact surfaces. Previous studies detected the biofilm formation and efficacy of sanitizers on food contact surfaces, but fewer examined within and or on the farm components. This study aims to study the ability of C. jejuni to form biofilm on plastic, galvanized wire and concrete surfaces as simulating in poultry farms and evaluate the efficacy of five commercial disinfectants; Pyam ® , Klorsept ® , Calcium hypochlorite ® , PronTech ® and Virukill ®. All which used at two concentrations 0.5% and 1%. The used surfaces showed biofilm formation by different degrees. Our results revealed that Pyam ® , Klorsept ® and Ca. hypochlorite ® showed the highest logarithmic reductions of biofilm count followed by potassium peroxymonosulfate and halide NaCl combination Virukill ® while the lowest reductions were obtained using QAC (Alkyl Dimethyl Benzyl Ammonium Chloride 40% with 60 % Urea, PronTech ®). In conclusions, the use of efficient disinfectants reduces the risk of C. jejuni infections through direct and indirect routes of infection.