Background: Toxoplasma gondii is a protozoan parasite, a member of the phylum Apicomplexa. Felids are definitive hosts, and all warm-blooded animals and humans are intermediate hosts. The clinical symptoms of toxoplasmosis among chickens are mostly subclinical, but the infection of chickens and eggs is important as a source of protein for human consumption. Objectives: This study aimed to detect T. gondii in chicken meat and egg by molecular examination.Methods: In this study, 100 chicken legs, 50 eggs of free-range hens, and 50 eggs of industrial hens were collected from different stores in Semnan City, Iran. The samples were inspected for the Toxoplasma B1 gene after DNA extraction.Results: According to the results, Toxoplasma DNA was detected in 23% of chicken legs, 36% of eggs of free-range hens, and 20% of eggs of industrial hens. The infection rate was not significantly different between eggs of free-range and industrial hens (P>0.05). Conclusion: Therefore, Toxoplasma is present in chicken meats and eggs in Semnan, Iran, and it is recommended that people eat well-cooked chicken meat and eggs for disease control and feed domestic carnivores with cooked meat to prevent the parasite life cycle.

BACKGROUND: Newcastle disease virus (NDV) majorly infects the poultry, and despite high rates of vaccination, it is still circulating in different geographical regions. Due to the high mortality rate, the economic loss of Newcastle disease (ND) is enormous. OBJECTIVES: The molecular characterization of NDV isolates from chicken farms in Northern Iran, during 2017-2018, was the main goal of this study. METHODS: We isolated and characterized five NDVs from commercial broiler and backyard chicken farms during severe disease outbreak. The partial coding sequence of fusion (F) genes of isolates was determined and compared with those of other published NDVs. RESULTS: Phylogenetic analysis revealed that all of the isolates were grouped into sub-genotype VII.1.1 (formerly known as VIIl). All isolates carried multi‐basic amino acid residues at the cleavage site of fusion protein, typical of virulent strains. Studied NDV isolates had high homology with the prevalent genotype NDV strains that currently circulate in China and Republic of Korea (96.94%). CONCLUSIONS: Our results suggested that NDV sub-genotype VII.1.1 (VIIl), circulating among chicken farms, may be a dominant sub-genotype. Considering the genetic variation between the used vaccine strains (B1, LaSota, and Clone 30, all belonging to genotype II) and circulating NDVs, it is recommended that a contemporary homologous virus should be developed as the vaccine strain to avert the outbreaks of genotype VII viruses.

Background: Although Escherichia coli (E. coli)is a part of intestinal normal microflora of warm-blooded animals, includingpoultry, outbreaks occur in poultry raised below standard sanitation and duringthe course of respiratory or immunosuppressive diseases. Avian pathogenic E.coli (APEC) harbors several genes associated with virulence andpathogenicity. APEC strains are responsible for some diseases in poultryincluding colibacillosis, swollen head syndrome, yolk sac infection, omphalitisand coli granuloma. OBJECTIVES:  Theaim of this study was examination of the presence and frequency of threeimportant virulence genes in intestinal and extra-intestinal (liver) E. coliisolates from chicken of Khuzestan province in the southwest of Iran. METHODS:Totally 120 (60 intestinal and 60 liver) E. coli isolates were examinedby polymerase chain reaction (PCR) for the presence of aerobactin (iutA),temperature sensitive hemagglutinin (tsh) and fimbriae type 1 (fimH )genes.  RESULTS: The results showedthat tsh, iutA and fimH are respectively present in 78.3%, 70% and 61.7% ofliver isolates while in intestinal ones the frequency of these genes was 21.7%,41.7% and 41.7% respectively. The most prevalent genotypes in extra intestinaland intestinal isolates were tsh+fimH+iutA+ and tsh-fimH-iutA-respectively. CONCLUSIONS: It seems that these sets of virulence genes are significantly moreprevalent (P<0.05) in extra intestinal isolates and probably these genesplay an important role in the pathogenesis of APEC isolates in the southwest ofIran. Although these virulence genes were not present in all APEC isolates  their frequencies were high and using theproducts of these genes in vaccines may be effective in protecting againstinfections caused by this bacterium

BACKGROUND:Class II transactivator (CIITA) is a dominanttranscriptional element, controlling numerous genes in theimmune system. CIITA is expressed in a constitutive pattern inantigen presenting cells although its expression can occur inother cell types. Since the revelation of CIITA, there have beenconsiderable advances toward understanding its role as anactivator of MHC II genes in humans and mice; nonetheless,there is a lack of published data for this gene in other animals suchas chickens. OBJECTIVES: The goals of this study were todetermine the expression of class II transactivator (CIITA) inchicken and analysis of the CIITA gene sequence between fourIranian indigenous chicken ecotypes. METHODS:After securingthe research accuracy and optimization of reaction conditions,cDNA and DNA samples of gene were obtained from fourIranian indigenous chicken ecotypes. The PCR and RT-PCRproducts were sequenced and the data were analyzed bybioinformatics software. RESULTS: Comparison of thesequencing results with the reference sequence of the red junglefowl revealed that these sequences belonged to the predictedCIITA gene. There was a high conservation rate in the sequenceof CIITA. CONCLUSIONS: Our results indicated that like otherspecies, CIITA is transcripted in chickens' immune system cells.Further studies on chickens must be done to reveal CIITAroles inimmune responses of chickens.