<abstract xmlns="http://www.w3.org/1999/xhtml">

<sec id="j_jvetres-2022-0014_s_005">
<h3>Introduction</h3>
<p><italic>Ornithobacterium rhinotracheale</italic> (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.</p>
</sec>
<sec id="j_jvetres-2022-0014_s_006">
<h3>Material and Methods</h3>
<p>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.</p></sec>
<sec id="j_jvetres-2022-0014_s_007">
<h3>Results</h3>
<p>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 <italic>Mycoplasma gallisepticum</italic> and <italic>M. synoviae</italic> in some samples but the total absence of <italic>Bordetella avium</italic>. The upper respiratory tract in turkeys was dominated by two major phyla Firmicutes and Proteobacteria. At the genus level, the genera <italic>Ornithobacterium, Mycoplasma, Gallibacterium, Avibacterium</italic>, and <italic>Escherichia-Shigella</italic> were found which may include pathogenic bacteria that can cause clinical symptoms.</p></sec>
<sec id="j_jvetres-2022-0014_s_008">
<h3>Conclusion</h3>
<p>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.</p>
</sec>
</abstract>

Introduction
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.


Material and Methods
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.

Results
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.

Conclusion
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.

Occurrence of <italic>Ornithobacterium rhinotracheale</italic> in Polish turkey flocks

Journal of Veterinary Research

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Introduction
Ornithobacterium rhinotracheale (ORT) causes significant economic losses to the poultry industry around the world. The bacterium often affects...

Year	Number of flocks	Samples (flocks)		Number of positive flocks (%) in real-time PCR	Number of positive flocks (%) in PCR	Flocks with signs
Year	Number of flocks	Swabs	Tissue	Number of positive flocks (%) in real-time PCR	Number of positive flocks (%) in PCR	Flocks with signs
2015	67	66	1	11 (16.42)	10	3
2016	17	10	7	6 (35.29)	5	5
2017	14	14	-	0	0	0
2018	10	8	2	6 (60)	6	2
2019	20	17	3	14 (70)	13	3
2020	5	3	2	4 (80)	4	0
Total	133	118	15	41 (30.83)		13

Occurrence of Ornithobacterium rhinotracheale in Polish turkey flocks

Published Online: Mar 25, 2022

Page range: 77 - 84

Received: Oct 21, 2021

Accepted: Mar 03, 2022

DOI: https://doi.org/10.2478/jvetres-2022-0014

Keywords
turkey, phylogenetic analysis, 16S rRNA

© 2022 O. Kursa et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Fig. 1

Fig. 2

Fig. 3

Fig. 4

Number of samples used in this study

Occurrence of Ornithobacterium rhinotracheale in Polish turkey flocks

Published Online: Mar 25, 2022

Page range: 77 - 84

Received: Oct 21, 2021

Accepted: Mar 03, 2022

DOI: https://doi.org/10.2478/jvetres-2022-0014

Keywordsturkey, phylogenetic analysis, 16S rRNA

© 2022 O. Kursa et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Fig. 1

Fig. 2

Fig. 3

Fig. 4

Number of samples used in this study

Keywords
turkey, phylogenetic analysis, 16S rRNA