Ornithobacterium rhinotracheale (ORT) causes significant economic losses to the poultry industry around the world. The bacterium often affects poultry as part of multiple infections causing very serious clinical signs that are usually not limited only to the respiratory system. This study’s main objective was the retrospective detection and identification of ORT in turkey flocks.

Ornithobacterium rhinotracheale (ORT), is a bacterium that cause respiratory tract infection, has led to significant problems in the intensive poultry production. The current study aimed to isolate and identify ORT from broiler chickens, to detect antibacterial sensitivity and resistance of ORT isolates, and to test experimental infection of ORT in broiler chickens. One hundred eighty samples including tracheas, lungs and air sacs were subjected to isolation and phenotypic identification. Twelve suspected ORT isolates were used for molecular identification. Agar gel precipitation test was used to determine serotype of ORT isolates. Antibacterial sensitivity and resistance of ORT isolates were tested against 14 antibacterial drugs using standard disk diffusion technique. Pathogenicity of ORT was tested by experimental infection in broiler chickens. Results revealed that the incidence of ORT infection in broiler chickens in Assiut Governorate is 17.77% using isolation and phenotypic methods of identification, while it is 3.33% using molecular identification. Serological identification of ORT isolates indicated that all tested isolates, were belonged to serotype A. All ORT isolates were resistant to gentamycin, amoxycillin and cephradine with 100% incidence, where, 100% isolates were sensitive to colistin and doxycycline, 50% of isolates were sensitive to ampicillin and streptomycin, and 16.67% of isolates were sensitive to neomycin and trimethoprim. Living Newcastle attenuated vaccine, Lasota vaccine, exaggerates the clinical signs and lesions of ORT experimental infection.

Ornithobacterium rhinotracheale (ORT) causes significant economic losses to the poultry industry around the world. The bacterium often affects poultry as part of multiple infections causing very serious clinical signs that are usually not limited only to the respiratory system. This study’s main objective was the retrospective detection and identification of ORT in turkey flocks. ORT identification was performed in 6,225 samples taken from 133 different flocks between 2015 and 2020. Molecular methods were used, specifically real-time PCR and traditional PCR. We focused on partial 16S rRNA gene sequences of isolates, which were compared with sequences obtained from GenBank. The reaction products were analysed phylogenetically. Molecular methods indicating secondary infections was carried out, and the bacterial composition of the upper respiratory tract was 16S metasequenced for selected flocks to identify any other pathogens. The presence of ORT was detected in 30.83% of samples by real-time PCR and 28.57% by PCR. Phylogenetic analysis of the PCR products from the turkeys samples showed that their sequences resolved into two main genetic groups. Tests for the occurrence of secondary infections showed the presence of Mycoplasma gallisepticum and M. synoviae in some samples but the total absence of Bordetella avium. The upper respiratory tract in turkeys was dominated by two major phyla Firmicutes and Proteobacteria. At the genus level, the genera Ornithobacterium, Mycoplasma, Gallibacterium, Avibacterium, and Escherichia-Shigella were found which may include pathogenic bacteria that can cause clinical symptoms. The results of the analysis of multiple infection carried out in flocks with respiratory signs are probably associated with outbreaks of ornithobacteriosis in turkey flocks in Poland.

Turkey histomonosis poses a serious threat to poultry production due to the ban on the use of effective drugs. The aim of the study was to evaluate the influence of a phytoncidal feed supplement on the course of histomonosis. The preparation was also analysed for immunomodulatory properties. Clinical observations and production monitoring were conducted in a flock of turkeys with histomonosis from their 11ᵗʰ to 56ᵗʰ weeks of life which were treated with the adiCoxSᴼᴸPF soluble supplement in a dose of 2.5 mL/L water. Later the preparation was used in a preventive dose (1 mL/L). The influence on the immune system was evaluated in broiler turkeys having been given adiCoxSᴼᴸPF for 3 days in doses of 1 or 3 mL/L. The T and B lymphocyte percentages in turkey blood and spleen tissue were analysed with flow cytometry. ELISA was implemented to evaluate antibody titres after Ornithobacterium rhinotracheale vaccination, and biochemical analyses were performed to evaluate the supplement’s safety. AdiCoxSᴼᴸPF was found effective in therapy and prevention of histomonosis. Additionally, adiCoxSᴼᴸPF stimulated both humoral and cell-mediated immune mechanisms, without impairing the functions of internal organs. The treated turkeys also yielded better production results (eggs/hen, fertility, and hatchability). AdiCoxSᴼᴸPF possesses immunomodulatory properties and it can be used successfully in the prevention and therapy of histomonosis in turkeys.

Ornithobacterium rhinotracheale (ORT) is a bacterium that causing respiratory problems, growth retardation, high mortality, and drop in egg productions in poultry. The aim of the present investigation was to determine the seroprevalence and potential risk factors associated with the ORT infection in commercial poultry flocks in selected areas of Bangladesh. A total of 1920 serum samples were collected from 270 poultry farms including broiler (n=397), broiler breeder (n=430), layer (n=738), and a local breed namely Sonali (n=355) in Bangladesh were collected during 2017-2018 and the samples were tested for ORT antibodies using indirect Enzyme-Linked Immunosorbent Assay (iELISA). At individual level, the prevalence of ORT antibodies in examined samples was 39.05% (95% CI: 36.87-41.29) and at farm level, it was 50.74% (95% CI: 44.61-56.85). In multivariate Generalized Estimating Equation (GEE) analysis, sampling area, farm category, types of chicken biosecurity condition and types of drinker used were identified as positively correlated with potential risk factors (p<0.05) for the seroprevalence of ORT in poultry farms. Therefore, it could be concluded that ORT is prevalent among commercial poultry of Bangladesh. Proper biosecurity measures at farm level and vaccination of birds against the ORT are highly recommended.

This study was carried out for investigation of an outbreak in Karachi. A disease outbreak in poultry was reported during April, 2000 in Karachi. The main symptoms included respiratory distress, sneezing and gasping. Autopsy of dead birds showed tracheitis, air-sacculitis and involvement of lungs. The morbid material was collected for processing in the laboratory. During the investigation for isolation of pathogenic bacteria or virus, Ornithobacterium rhinotracheale was isolated on 5% sheep blood agar plates in an atmosphere containing 5-10% CO2 at 37 degree C and identified through biochemical and fermentation tests. A Lasota like virus was also isolated from the same material which showed HA activity but was found negative to Avian Influenza virus against known Avian Influenza serum. The isolated virus was sent to Central Veterinary Laboratory, Weybridge, U.K. which confirmed it to be Lasota virus having comparatively high Intracerebral Pathogenicity Index (ICPI) as 0.90. Attempts for the transmission of the disease in susceptible healthy broiler chicks was successful through aerosol route using combination of inoculum of the isolated bacteria and virus. On post-mortem of infected birds air- sacculitis, tracheitis and unilateral pneumonia were noticed. Again ORT and NDV were isolated from the material harvested from these chicks. According to the observations of these experiments, it was concluded that the isolated ORT had a triggering effect on Lasota virus or vice versa. The environmental temperature and other stress factors might have aggravated the disease problem.