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Avian influenza virus subtype H9N2 is widely circulating around the globe affecting many species of animal including mammals and birds as well as human beings. The virus has pandemic potential due to segmented nature of the viral genome. Ultra-structural features of apoptosis in field and experimental infection of H9N2 avian influenza virus were studied. Freshly dead birds from affected broiler farms and experimentally infected broiler chickens with H9N2 subtypes were subjected to routine necropsy. Post-mortem findings in different organs were recorded. Appropriate specimens from the trachea were taken for electron microscopy studies. In electron microscopy study, frequent apoptotic bodies were observed in the epithelial cells of the trachea. Increase of antibody titer to H9N2 virus following challenge with the virus in experimental group indicates that the infectious cycle has been initiated in the affected birds. [ABSTRACT FROM AUTHOR]

The objective was to investigate the multidrug resistance and presence of class 1 and 2 integrons in 300 Escherichia coli isolates obtained from 20 broiler farms during three rearing periods (one-day-old chicks, thirty-day-old chickens, and one day before slaughter) in Fars, South Iran. Results showed that 81.00%, 82.00%, and 85.00% of isolates were multidrugresistant on the first day, thirty-day-old chickens, and one day before slaughter, respectively. Multidrug-resistant E. coli isolates were further examined for the presence of class 1 and 2 integrons using PCR assay. The existence of class 1 integron-integrase gene (intI1) was confirmed in 68.40%, 72.70%, and 60.90% of multidrug-resistant isolates from stage 1, stage 2, and stage 3 of the rearing period, respectively. The frequency of class 2 integron-integrase gene (intI2) during the first to the third stage of sampling was 2.60%, 25.50%, and 30.40%. Also, sequence analysis of the cassette arrays within class 1 integron revealed the presence of the genes associated with resistance for trimethoprim (dfrA), streptomycin (aadA), erythromycin (ereA), and orfF genes. The results revealed that percentages of antimicrobial resistance in E. coli isolates were significantly higher in the middle and end stages of the rearing period. In conclusion, widespread dissemination of class 1 integrons in all three stages and rising trends of class 2 integrons existence in E. coli isolates during the rearing period of broiler chickens could exacerbate the spread of resistance factors among bacteria in the poultry industry. Future research is needed to clarify its implication for human health. [ABSTRACT FROM AUTHOR]

BACKGROUND: Ornithobacterium rhinotracheale (ORT) is a remarkable pathogen in the world poultry industry. The vaccine against this agent is used in poultry farms to prevent infection and reduce the incidence of disease. OBJECTIVES: In the present study, the efficacy of the first Iranian inactivated ORT vaccine produced by the Razi Vaccine and Serum Research Institute was evaluated using the experimental challenge system . METHODS: Ninety day-old specific-pathogen-free White leghorn chickens were divided randomly into five groups of 18 chickens. The birds were housed in separate specific cages in isolation rooms. At the age of 14 days, the birds of two groups were vaccinated. Afterwards, at the age of 42 days, two groups of unvaccinated chickens and all of the vaccinated subjects were challenged with the LaSota strain of Newcastle Disease Virus (NDV) and ORT. One group of unvaccinated birds was maintained as the negative control. Blood samples were taken from chickens on days 14 (before vaccination) and 42 (before challenge) of the experiment. In addition, blood samples were collected on days 2, 4, 6, 8, 10, and 12 after the challenge (AC). On days 2, 4, 6, 8, 10, and 12 after challenging with ORT, the isolation and molecular detection of the bacteria were performed on samples from the trachea, lungs, air sacs, liver, and spleen. RESULTS: Following vaccination with the Razi ORT vaccine, the titers of antibody in vaccinated chickens were shown to be significantly higher than those of unvaccinated birds. In vaccinated groups, the ORT was not recovered in cultures from lungs, trachea, and air sacs. In the unvaccinated birds challenged with ORT, bacteria were isolated from lungs, trachea, and air sacs. Using the polymerase chain reaction method, ORT was only detected from samples of lungs, trachea, and air sacs 2 days after challenge (DAC) in vaccinated groups. Meanwhile, ORT was detected in lungs, trachea, and air sacs until 4 days after challenge in unvaccinated birds. CONCLUSIONS: We concluded that the Razi ORT vaccine was effective in protecting layer chickens against infection with serotype A of the ORT. [ABSTRACT FROM AUTHOR]

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Avian influenza virus subtype H 9 N 2 is widely circulating around the globe affecting many species of animal including mammals and birds as well as human beings. The virus has pandemic potential due to segmented nature of the viral genome. Ultra-structural features of apoptosis in field and experimental infection of H 9 N 2 avian influenza virus were studied. Freshly dead birds from affected broiler farms and experimentally infected broiler chickens with H 9 N 2 subtypes were subjected to routine necropsy. Post-mortem findings in different organs were recorded. Appropriate specimens from the trachea were taken for electron microscopy studies. In electron microscopy study, frequent apoptotic bodies were observed in the epithelial cells of the trachea. Increase of antibody titer to H 9 N 2 virus following challenge with the virus in experimental group indicates that the infectious cycle has been initiated in the affected birds., Competing Interests: The authors declare that they do not have conflict of interest., (© 2022 Urmia University.)

Background: Campylobacter is one of the leading bacterial species causing foodborne illnesses in humans. Antimicrobial agents have been extensively used for treatment of Campylobacter infections; but in the recent years, both animal and human isolates of this bacterium have shown resistance to several antibiotics such as tetracycline., Objectives: The aim of this study was to investigate the presence of genetic determinants of tetracycline resistance in Campylobacter spp. recovered from poultry carcasses in Shiraz, Iran., Materials and Methods: Eighty-three thermophilic Campylobacter spp. Isolates were first identified based on multiplex polymerase chain reaction (PCR) and then screened for presence of tetracycline resistance genes (tet (A), tet (B), tet (O) and te (S)) by PCR., Results: The overall prevalence of Campylobacter jejuni and C. coli among the examined isolates was 51.8% and 48.2%, respectively. Tetracycline resistance genes of tet (B) and tet (S) were not seen among these Campylobacter spp. Isolates, whereas the most common tet gene identified was tet (O), found in 83.1% (69/83) of all the isolates. The tet (O) gene sequence comparison between C. jejuni and C. coli showed 100% similarity and these sequences (JX853721and JX853722) were also identical to the homologous sequences of other strains of Campylobacter spp. existing in the GenBank databases. In addition, tet (A) was found in 18% (15/83) of Campylobacter spp. isolates. To our knowledge, this represents the first report of tet (A) in Campylobacter spp. There was 100% homology between the sequences of tet (A) from this study (JX891463 and JX891464) and the tet (A) sequences mentioned for other bacteria in the GenBank databases., Conclusions: The high prevalence of tet (O) resistance gene along with new detection of tet (A) resistance gene in Campylobacter spp. isolated from poultry carcasses revealed an extensive tetracycline resistance among Campylobacter isolates from poultry in Iran. It emphasized the need for cautious use of tetracycline in poultry production to decrease the extension of tetracycline-resistant Campylobacter spp.