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

<sec>
<h3>Introduction</h3>
<p><italic>Gallibacterium anatis</italic> is an opportunistic bacteria inducing a range of clinical signs in poultry. <italic>Gallibacterium anatis</italic> strains show multidrug resistance to antibacterial substances. The purpose of this study was to examine the susceptibility of <italic>G. anatis</italic> biovar <italic>haemolytica</italic> isolates collected from the respiratory, reproduction and gastrointestinal tracts of chickens to different antibiotics from various classes.</p>
</sec>
<sec>
<h3>Material and Methods</h3>
<p><italic>Gallibacterium anatis</italic> biovar <italic>haemolytica</italic> was identified in tracheal swab and gastrointestinal and reproductive tract tissue samples from Polish layer and broiler chicken flocks. Twenty six isolates with β-haemolysis capability, each from a different flock, obtained from the respiratory (n = 8), reproductive (n = 10) and gastrointestinal (n = 8) tracts were selected and identified by matrix-assisted laser desorption/ionisation–time-of-flight mass spectrometry after culturing. A PCR method targeting the 16S genes was used for verification of isolates. The isolates’ susceptibility to 20 antimicrobials was evaluated using the disc diffusion method for 8 drugs and the dilution method for the other 12. In addition, they were tested for the presence of the <italic>Gtx</italic>A, <italic>gyr</italic>B and <italic>flf</italic>A virulence genes and <italic>bla</italic>ROB, <italic>aph</italic>A, <italic>tet</italic>B and <italic>tet</italic>H antibiotic resistance genes by PCR.</p>
</sec>
<sec>
<h3>Results</h3>
<p>The most prevalent antibiotic resistance was to tilmicosin, tylosin and quinupristin/dalfopristin (all 100%), erythromycin (96.2%), tetracycline (96.2%), linezolid (92.3%) and teicoplanin (92.3%). Universal susceptibility was to only one antibiotic, chloramphenicol. Statistically significant differences were found between the resistance of gastrointestinal tract strains and that of strains from other tracts to daptomycin, gentamicin, ciprofloxacin and colistin. The <italic>Gtx</italic>A and <italic>gyr</italic>B genes were detected in 100% of isolates and <italic>flf</italic>A in 19.2%. The isolates most frequently contained <italic>tet</italic>B and less frequently <italic>tet</italic>H and <italic>aph</italic>A, and did not contain <italic>bla</italic>ROB.</p>
</sec>
<sec>
<h3>Conclusion</h3>
<p>Most <italic>G. anatis</italic> biovar <italic>haemolytica</italic> isolates were resistant to many classes of antibiotics. Therefore, it is necessary and important to be vigilant for the occurrence of these bacteria and thorough in their diagnosis.</p>
</sec>
</abstract>

Introduction
Gallibacterium anatis is an opportunistic bacteria inducing a range of clinical signs in poultry. Gallibacterium anatis strains show multidrug resistance to antibacterial substances. The purpose of this study was to examine the susceptibility of G. anatis biovar haemolytica isolates collected from the respiratory, reproduction and gastrointestinal tracts of chickens to different antibiotics from various classes.


Material and Methods
Gallibacterium anatis biovar haemolytica was identified in tracheal swab and gastrointestinal and reproductive tract tissue samples from Polish layer and broiler chicken flocks. Twenty six isolates with β-haemolysis capability, each from a different flock, obtained from the respiratory (n = 8), reproductive (n = 10) and gastrointestinal (n = 8) tracts were selected and identified by matrix-assisted laser desorption/ionisation–time-of-flight mass spectrometry after culturing. A PCR method targeting the 16S genes was used for verification of isolates. The isolates’ susceptibility to 20 antimicrobials was evaluated using the disc diffusion method for 8 drugs and the dilution method for the other 12. In addition, they were tested for the presence of the GtxA, gyrB and flfA virulence genes and blaROB, aphA, tetB and tetH antibiotic resistance genes by PCR.


Results
The most prevalent antibiotic resistance was to tilmicosin, tylosin and quinupristin/dalfopristin (all 100%), erythromycin (96.2%), tetracycline (96.2%), linezolid (92.3%) and teicoplanin (92.3%). Universal susceptibility was to only one antibiotic, chloramphenicol. Statistically significant differences were found between the resistance of gastrointestinal tract strains and that of strains from other tracts to daptomycin, gentamicin, ciprofloxacin and colistin. The GtxA and gyrB genes were detected in 100% of isolates and flfA in 19.2%. The isolates most frequently contained tetB and less frequently tetH and aphA, and did not contain blaROB.


Conclusion
Most G. anatis biovar haemolytica isolates were resistant to many classes of antibiotics. Therefore, it is necessary and important to be vigilant for the occurrence of these bacteria and thorough in their diagnosis.

Antibiotic resistance of <italic>Gallibacterium anatis</italic> biovar <italic>haemolytica</italic> isolates from chickens

Journal of Veterinary Research

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

Antibiotic resistance of  biovar  isolates from chickens

Introduction
Gallibacterium anatis is an opportunistic bacteria inducing a range of clinical signs in poultry. Gallibacterium anatis strains show multidrug...

Antibiotic resistance of Gallibacterium anatis biovar haemolytica isolates from chickens

Published Online: Mar 23, 2024

Page range: 93 - 100

Received: Aug 18, 2023

Accepted: Feb 02, 2024

DOI: https://doi.org/10.2478/jvetres-2024-0007

Keywords
Gallibacterium anatis, antibiotic resistance, chickens

© 2024 Olimpia Kursa et al., published by Sciendo

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

Antibiotic resistance of Gallibacterium anatis biovar haemolytica isolates from chickens

Published Online: Mar 23, 2024

Page range: 93 - 100

Received: Aug 18, 2023

Accepted: Feb 02, 2024

DOI: https://doi.org/10.2478/jvetres-2024-0007

KeywordsGallibacterium anatis, antibiotic resistance, chickens

© 2024 Olimpia Kursa et al., published by Sciendo

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

Keywords
Gallibacterium anatis, antibiotic resistance, chickens