<p>N-terminal amino acid sequence groups.</p>

Bordetella bronchiseptica is a highly contagious veterinary bacterial respiratory pathogen with a broad host range that can cause a variety of clinical disease outcomes ranging from asymptomatic carriage to severe pneumonia. B. bronchiseptica fimbriae mediate attachment to respiratory epithelium and are considered to serve as potential protective antigens. Several comparative genomic studies involving B. bronchiseptica strains have demonstrated an overall low level of genomic variability. The region located within the fimX locus is one of the few regions in which genomic variability has been reported. The goal of this study was to comprehensively evaluate the genomic variability harbored within the fimX locus among B. bronchiseptica strains. Our analysis revealed that the genetic variability identified within the fimX locus included both the number of genes harbored, as well as the type of predicted fimbrial subunit gene types contained within the fimX locus. A total of six different fimbrial subunit gene types were identified among the B. bronchiseptica genome assemblies analyzed in this study. Comparative analysis data also suggests that the diversity among the fimbrial subunit genes located within the fimX locus was likely generated by homologous recombination.支气管败血波氏杆菌（Bordetella bronchiseptica）是一种高传染性兽医源性细菌性呼吸道病原体，宿主范围广泛，可引发从无症状携带至重症肺炎等多种临床病症。该菌的菌毛（fimbriae）可介导其黏附于呼吸道上皮细胞，被视为潜在的保护性抗原。多项针对支气管败血波氏杆菌菌株的比较基因组研究显示，其基因组整体变异水平较低，而fimX基因座（fimX locus）内的区域是目前已报道存在基因组变异的少数区域之一。本研究旨在全面评估不同支气管败血波氏杆菌菌株fimX基因座内的基因组变异情况。分析结果表明，fimX基因座内鉴定出的遗传变异既包括所携带基因的数量，也涵盖该基因座内预测的菌毛亚基基因类型。本研究分析的支气管败血波氏杆菌基因组组装序列中，共鉴定出6种不同的菌毛亚基基因类型。比较基因组分析数据还显示，fimX基因座内的菌毛亚基基因多样性可能由同源重组所产生。