nariman sheikhi

Light is an important factor in the functioning of the body of birds, especially the immune system. Management of the lighting program in closed systems of poultry production, mainly by affecting the concentration of melatonin, can be operational on the effectiveness of vaccination. Newcastle disease can cause extensive damage to the poultry industry. Therefore, its timely diagnosis and assessment of the success of vaccination with methods such as the hemagglutination inhibition test are of particular importance. This study investigated the effect of two photoperiods on antibody titer against Newcastle virus following vaccination. Four groups of Ross broilers were examined for six weeks. Groups A and B received the live Newcastle vaccine twice, and groups C and D were not vaccinated against Newcastle. Groups A and C received a lighting program from the management handbook of Ross Broiler, and groups B and D received the continuous lighting program (23L:1D). During the breeding period, blood samples were taken six times from each group, and the HI test measured the antibody titer. The results showed that despite the higher antibody titer in group B compared to group A, this difference was not statistically significant (P>0.05). The feed conversion rate was higher in the groups that received the continuous photoperiod, and their mortality rate was lower than that of the other two groups. Comparing the results of the present study with those of various studies and articles shows the importance of the lighting regime in the success of vaccination.

Ornithobacterium rhinotracheale (ORT) is an economically important bacterial pathogen of poultry worldwide. The Aim of the present study was conducted to isolation, detection and determination of antibiotic sensitivity of ORT isolates in commercial poultry flocks with respiratory signs in Mazandaran province, northern Iran. Tracheal swab samples were taken from 60 different flocks, after cultivation on a selective medium, suspected colonies were subjected to biochemical and molecular identification of ORT. Then, confirmed isolates were aimed to antibiotic resistance assay. A total of 13 isolates, including seven isolates from broiler flocks (19.44%) and six isolates from broiler breeder flocks (33.33%) were obtained. All ORT isolates that were positive by culture were also detected to be positive by the PCR. The most resistance rates among all ORT isolates were obtained for ampicillin, erythromycin, ceftriaxone, and penicillin (100%). The majority of ORT isolates were susceptible to furazolidone. According to the results, the isolates showed different antibiotic resistance profiles, and most of the strains proved multiresistant. This can indicate the circulation of various multidrug resistant strains among poultry farms in northern Iran.

Avian infectious bronchitis virus (IBV) has a great potential for genetic variability which leads to the generation of new virus strains. The changes in the IBV genome often cause alterations in virulence, tissue tropism, and viral replication in the host tissues.

This study was conducted to identify the virus variant strains in the trachea, lungs, and kidneys of infected birds. The possible relationship of IBV variants with the relative quantity of virus in each organ was also investigated.

The IBV variant strains were detected by polymerase chain reaction (PCR) and direct sequencing. Amongst infected commercial broiler flocks sampled at Golestan and Mazandaran provinces of Iran, nine flocks (three flocks per variant) were selected based on the identified variants. Trachea, lung, and kidney samples of five birds per flock were examined for the presence of the virus and variants. Moreover, the virus was quantified in target organs using real-time quantitative PCR.

Based on the results of PCR and sequencing, three IBV variants were selected, namely A, B, and C. Virus types A and B were detected in all target organs, while type C was detected in the trachea and kidney. Virus type C had the highest quantity of 17.02±5.22 and virus type A showed the lowest quantity of 5.68±2.4 in infected tissues. The relative quantity of virus detected in tissues significantly correlated with the IBV variant.

Genetic polymorphism in IBV field strains was revealed to have significant correlations with viral quantity in the lung, trachea, and kidney. Our findings are an update of the current knowledge on the associa-tions between viral genotype, virulence, and pathogenicity.

Infection with Infectious bronchitis virus (IBV) and avian pathogenic Escherichia coli (APEC) is an important respiratory infection worldwide. Apoptosis is a physiological process of cell death that occurs as part of normal development and responds to a variety of physiological and pathophysiological stimuli. The identification of molecular mechanisms of action or inaction of key apoptotic proteins is important. This study aimed to investigate apoptotic related genes in the trachea tissue of infected (IBV variant 2, and APEC serotype O78: K80) SPF chickens group compared to the control group.

Forty SPF chickens was divided into 2 groups. Differential transcriptional profile in the infected SPF chickens trachea tissue was compared to those of control group in the early stage of infection by Illumina RNA-seq technique paired-end and strand-specific sequencing. Differentially expressed genes (DEGs) of transcriptome profiling of the trachea from the infected group were identified. Gene ontology category, KEGG pathway, and STRING analysis were analyzed to identify relationships among differentially expressed genes.

Twenty-eight apoptotic genes were identified. They consisted of six pathways related to cell death: the extrinsic pathway, intrinsic pathway, endoplasmic reticulum stress pathway, MAPK signaling pathway, and cell death by NFkB and activates mTOR pathway and some regulator and apoptosis inhibitors.

All of the apoptotic genes in our study were up-regulated. Among these genes, the more fold change value was for TRADD and BCL2A1 genes, and the less fold change value was for MAP3K14, NFKB1, PIK3CB, and ITPR2 genes.

Mycoplasma gallisepticum (MG) is economically important pathogen of poultry causes airsacculitis and frequently infraorbital sinusitis in turkeys. Infections may remain without clinical signs, but they can make birds susceptible to secondary infections.This study was carried out for molecular detection and phylogenetic analysis of MG infections in commercial and backyard turkey flocks in some parts of Iran. A total number of 600 swab samples were collected from 18 commercial and 31 backyard turkey flocks. The PCR technique was performed for detecting 16S rRNA gene in the samples. Positive sample were subjected for sequencing of mgc2 gene. The results showed that 48.38% of backyard and 16.66% of commercial farms were positive for MG. These findings suggested the presence of MG in the commercial and backyard turkeys’ farms of Iran. The molecular analysis indicated high sequence similarity between some Iranian turkeys isolates with Indian and Pakistanian MG isolates. Furthermore, substitutions of MG nucleic acids and correlated amino acids sequences may lead to some antigenic modifications.