PATHOMORPHOLOGICAL DIAGNOSIS OF ORNITHOBACTERIOSIS IN ORNAMENTAL PIGEONS

The paper presents the results of the study of pathomorphological changes in organs in ornithobacteriosis in decorative pigeons with the establishment of the underlying disease, including the pathological signs associated and pathognomonic for the disease. The objects of the study were the corpses of fallen pigeons of the English postal and peacock breeds, at the age of 2-3 years, kept in a private farm on the territory of the Yemelyanovskiy district of the Krasnoyarsk Territory. Bacteriological examination of the material revealed the causative agent of ornithobacteriosis (Ornithobacterium rhinotracheale), and the causative agent of colibacillosis (Escherichia coli) was also found in 70,0 % of cases. In 70 % of the individuals, a complication was observed in the form of colibacillosis, characterized by serous-catarrhal gastroenterocolitis, spleen hyperplasia, and serous polyarthritis, to the underlying disease. The features of ornithobacterial infection in pigeons include the absence of pronounced serous-inflammatory edema of soft tissues in the head area, signs of serous-fibrinous aerosacculitis and the onset of the disease in birds of the older age group (2-5 years).

The first isolation and detection of Ornithobacterium rhinotracheale from swollen head syndrome-infected broiler flocks in Iraq

Background and Aim: The swollen head syndrome (SHS) makes up complex diseases that infect the upper respiratory tract in poultry and causes several economic losses. Furthermore, this syndrome is considered one of the multifactorial etiological agents. Therefore, this study isolated and molecularly detected Ornithobacterium rhinotracheale (ORT) in poultry. Materials and Methods: This study was conducted at 67 broiler farms that had birds observed to be infected with the SHS from September 2018 until August 2019. Subsequently, swabs were collected from their trachea, infraorbital sinuses, and lungs, after which obtained samples were treated through two methods: (a) The direct method, by uploading samples on FTA cards, and the indirect method using a transport media. Afterward, reverse transcription-polymerase chain reaction (RT-PCR) was used to analyze the directly treated samples; howeverAQ1, the culture method, followed by PCR, was used to analyze the indirectly treated samples. Next, a partial 16S RNA gene was isolated using four positive PCR products, after which the effect of 16 antibiotics was studied on the seven local ORT strains isolated. Results: The quantity of ORT isolated using the direct method was 28 (41.7%) samples, which were all positive for the strain. Identification was by direct molecular identification (RT-PCR) from samples loaded on FTA cards. Alternatively, 7 (10.4%) ORTs were detected from the indirect method, as obtained using the culture method and biochemical tests. Then, PCR was subsequently used to confirm the results. As observed, 784 bp bands were shown for all seven ORT isolates. Furthermore, results revealed a significant difference in the detection of ORT strains between direct and indirect methods, with p-value (<0.05) and standard deviation of the error ±0.038 for the direct, then ±0.061 for the indirect method. For further analysis on the strain types, four 784 bp PCR products were taken, then partial 16S ribosomal sequence typing was conducted. All these four strains were found to be recorded in NCBI for the 1st time as a local Iraqi strain, with accession numbers (MN931657, MN931656, MN931655, and MN931654). Notably, results also showed that all isolated strains were multidrug-resistant. Conclusion: From the results, ORT is proposed to be implicated as one of the etiological factors that cause SHSs in poultry. Phylogenetic analysis of the current ORT bacterial strains also showed that they are closely related to the Egyptian isolates.

Caracterización genotípica por MLST de Ornithobacterium rhinotracheale procedentes de aves de corral en el Perú

El objetivo del presente estudio fue la genotipificación de Ornithobacterium rhinotracheale. Se identificaron 36 cepas por pruebas moleculares y se realizó la genotipificación por Multilocus Sequence Typing (MLST). Los ensayos identificaron las secuencias tipo: N.T.1, N.T2 y N.T3, diferentes a la base de datos del NCBI y 19 alelos distintos con 229 sitios polimórficos. Además, 32 cepas pertenecen al genotipo común ST1. Los hallazgos identificaron al menos cuatro genotipos en pollos de varias regiones del Perú.

The immune status, oxidative and epigenetic changes in tissues of turkeys fed diets with different ratios of arginine and lysine

In the present experiment, it was assumed that the appropriate dietary ratio of arginine (Arg) to lysine (Lys) can improve the immune status and growth performance of turkeys. The aim of this study was to evaluate the effects of two inclusion rates of Arg relative to Lys in turkey diets with Lys content consistent with National Research Council (NRC) recommendations or 10% higher on the immune status of birds and indicators of protein and DNA damage due to oxidation, nitration or epigenetic changes. Another goal was to determine which dietary Arg:Lys ratio stimulates the immune response of turkeys vaccinated against Ornithobacterium rhinotracheale. The experiment was performed on 576 turkeys randomly assigned to four groups with two levels of Lys (low = NRC recommendation or high = NRC + 10%) and two levels of Arg (95% or 105% Arg relative to the content of dietary Lys). It was found that the Lys content of turkey diets should be 10% higher than that recommended by the NRC and combined with the higher Arg level (105% of Lys). Although the above Arg:Lys ratio did not improve the growth performance of birds, it stimulated their immune system and reduced protein nitration as well as protein and DNA oxidation.

Ornithobacterium rhinotracheale: MALDI-TOF MS and Whole Genome Sequencing Confirm That Serotypes K, L and M Deviate from Well-Known Reference Strains and Numerous Field Isolates

Ornithobacterium rhinotracheale is one of the most important bacterial agents of respiratory diseases in poultry. For correct identification and characterization of this fastidious bacterium, reliable diagnostic tools are essential. Still, phenotypic tests are used to identify O. rhinotracheale and serotyping is the most common method for characterization, despite known drawbacks and disadvantages such as divergent results, cross-reactivity between strains, or the non-typeability of strains. The intention of the present study was to evaluate MALDI-TOF MS and whole genome sequencing for the identification and characterization of O. rhinotracheale. For this purpose, a selection of 59 well-defined reference strains and 47 field strains derived from outbreaks on Austrian turkey farms were investigated by MALDI-TOF MS. The field strains originated from different geographical areas in Austria with some of the isolates derived from multiple outbreaks on farms within a year, or recurrent outbreaks over several years. MALDI-TOF MS proved a suitable method for identification of O. rhinotracheale to genus or species level except for 3 strains representing serotypes M, K and F. Phylogenetic analysis showed that most strains grouped within one cluster even though they were comprised of different serotypes, while serotypes F, K, and M clearly formed a different cluster. All field isolates from turkey farms clustered together, independent of the origin of the isolates, e.g., geographical area, multiple outbreaks within a year or recurrent outbreaks over several years. Whole genome sequencing of serotype M, K and F strains confirmed the extraordinary status and deviation from known fully-sequenced strains due to a lack of sequence similarity. This was further confirmed by alignments of single genes (16S-RNA and rpoB) and multilocus sequence typing although the demarcation was less obvious. Altogether, the results indicate that these three serotypes belong to a different species than O. rhinotracheale, and might even be members of multiple new species.

Detection of Laryngotracheitis Virus in Poultry Flocks with Respiratory Disorders in Slovenia

Infectious laryngotracheitis (ILT) is an acute, highly contagious infectious disease of the upper respiratory tract in chickens and other poultry species that causes significant economic losses in countries worldwide. Between 2017 and 2019, seven outbreaks of mild to severe respiratory disorders with high suspicion of ILT occurred in commercial and backyard poultry flocks in Slovenia. In all submissions, infection with ILT virus (ILTV) was confirmed by PCR, which is the first report of ILT in Slovenia. Circulating ILT strains were characterized by the sequence and phylogenetic analysis of two fragments of the ICP4 gene. Four strains—three detected in non-vaccinated flocks and one in a flock vaccinated against ILT—were identical or very similar to the chicken embryo–origin live virus vaccines, and the other three were closely related to Russian, Chinese, Australian, and American field strains and to tissue culture origin vaccine strains. As in other diseases, coinfections with other respiratory pathogens in confirmed ILT cases may cause a more severe condition and prolong the course of the disease. In our study, coinfections with Mycoplasma synoviae (7/7 tested flocks), infectious bronchitis virus (5/5 tested flocks), Mycoplasma gallisepticum (4/7 tested flocks), Ornithobacterium rhinotracheale (3/4 tested flocks), and avian pox virus (1/2 tested flocks) were confirmed, indicating the importance of these pathogens in the occurrence of ILT infections.

THERAPY OF POULTRY WITH ORNITHOBACTERIOSIS

Ornithobacteriosis, caused by Ornithobacterium rhinotracheale, belongs to the group of respiratory diseases that are currently one of the main problems in industrial poultry, as it leads to significant economic losses due to reduced productivity in commercial and reproductive herds, poor egg production, as well as reducing growth and increasing the death and culling of poultry, high treatment costs. Diagnosis of infections caused by Ornithobacterium rhinotracheale is often difficult because clinical symptoms and postmortem changes are not specific and can be easily confused with those of other infections. The difficulty also lies in the fact that Ornithobacterium rhino-tracheale can be isolated by bacteriological method only in the early stages of the disease. For effective prevention and treatment of ORT use veterinary medicines (VM), namely: tetracyclines; macrolides - tilmicosin, thiamulin; new generation macrolide – eulosin; semi-synthetic penicillin amoxicillin, amoxiclav; germacap - a mixture of aqueous solutions of citrates of zinc, germanium, silver, made on the basis of modern nanotechnology. In Ukraine, there are 29 names of VM for the treatment of poultry against ORT, consisting of one-, 2 and 3 components, namely: doxycycline hyclate, sarafloxacin hydrochloride, tiamulin, tylvalosin, tilmicosin, fluoropheniol; tilmicosin + bromhexine hydrochloride and gentamicin + fluorophenicol+ doxycycline. .Enzyme-linked immunosorbent assay (ELISA) is used to control the presence of ornithobacteriosis in poultry. The presence of antibodies to this pathogen in many species of poultry indicates its wide circulation. A total of 82 batches of broilers and 43 batches of laying hens were tested for ELT serum in ELISA. Positive average titers of antibodies to ORT were detected among meat crosses of 24 batches, which is 29.3%, and egg crosses of 35 batches, which is 81.4%, which indicates a wide circulation of ornithobacteria among poultry. When using Eulosin 625 mg / g at a dose of 25 mg / kg orally with water for 5 days for the treatment of ORT broilers found: high therapeutic effect of the medicine – 82 %, increase in average daily gain - by 2.7%, preservation - by 1.4%; and the efficiency index improved by 5.4 %. To successfully control ORT, it is necessary to carry out a set of veterinary and sanitary measures, as well as constant serological monitoring of blood sera from different age groups of poultry and turkeys in ELISA for specific antibodies, indicating its circulation, in order to conduct timely effective antibiotic therapy.