Molecular analysis of Bordetella bronchiseptica from respiratory-diseased patients.

Background:Bordetellabronchiseptica isa Gram-negative bacterium which known to cause respiratory disease in pet animals, and can colonize the human respiratory tract. Recently, B.bronchiseptica infections arerestricted to humans and increasing worldwide. Aim: Molecular indication of B.bronchiseptica in respiratory-diseased patientswith sequencing and phylogenetically analyzing close-relationship betweenstudy and global isolates, as well as measuring levels of interleukin-10 in study individuals. Materials and methods: An overall 150 patients with various clinical signs were subjected to collection of nasal swabs for molecular testing by the conventional PCR assay.Then, some positive B.bronchisepticaisolates were sequenced and analysedphylogeneticallyby the MEGA-11 software to identify its identity to the global NCBI-GenBankB.bronchiseptica isolates / strains.Also, samples of venous blood were obtained from the study population as well as from 30 healthy individuals to estimate serologically the levels of IL-10. Results: This study revealed that 10.99% of respiratory-diseased patients were positively infected with B.bronchiseptica. Phylogenetically,analyzing of study isolatesdetected the presence of similarity and mutations / changes at ranges of 98.14-99.91% and 0.0004-0.002%, respectively. Phylgenetic tree and multiple sequence alignment demonstrated that identity of study B.bronchiseptica isolates was to Mexican B.bronchiseptica strain (GenBank ID: FJ867619.1). The levels of IL-10 were elevated significantly in respiratory-diseased patients when compared to healthy, but not between the positively and negatively B.bronchiseptica infected patients. Conclusion: This study implicates molecularly,for the first time in Iraq, B.bronchiseptica in respiratory-diseased patients,close-relationship between the study and global isolates throughout phylogenetic analysis, and the level of IL-10 in respiratory-diseasedand the healthy population. Received: 10-08-2025 Revised: 12-08-2025 Accepted: 17-08-2025 Published: 21-08-2025 Copyright:© 2025 by the authors. Submitted for possible open access publication under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). Furthermore molecular studies are greatly needed to insight the role of B.bronchiseptica in other human infections.