Moraxella bovoculi is the most frequently isolated bacteria from the eyes of cattle with Infectious Bovine Keratoconjunctivitis (IBK), also known as bovine pinkeye. Two distinct genotypes of M. bovoculi, genotype 1 and genotype 2, were characterized after whole genome sequencing showed a large degree of single nucleotide polymorphism (SNP) diversity within the species. To date, both genotypes have been isolated from the eyes of cattle without clinical signs of IBK while only genotype 1 strains have been isolated from the eyes of cattle with clinical signs of IBK. We used 38 known genotype 1 strains and 26 known genotype 2 strains to assess the ability of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) to accurately genotype M. bovoculi strains using mass spectrum biomarkers. Mass spectrum data was analyzed with ClinProTools 3.0 software and six models were developed that classify strain genotypes with accuracies ranging from 90.6% - 100%. Finally, using four of the most genotype-specific peaks that also exhibited high peak intensities from the six automated models, we developed a customized model (UNL assisted model) that had recognition capability, validation, and classification accuracies of 100% for genotype classification. Our results indicate that MALDI-TOF MS biomarkers can be used to accurately discriminate genotypes of M. bovoculi without the need for additional methods.

中文翻译：

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使用MALDI-TOF质谱图快速区分牛莫拉氏菌基因型1和2。

牛莫拉氏菌是从牛眼中分离出的最常见的细菌，具有牛传染性角膜结膜炎（IBK），也称为牛红眼病。在全基因组测序显示物种中存在很大程度的单核苷酸多态性（SNP）多样性后，对肉食支原体的两个不同基因型进行了表征，即基因型1和基因型2。迄今为止，已经从无IBK临床症状的牛眼中分离出两种基因型，而从具有IBK临床症状的牛眼中仅分离了基因型1菌株。我们使用38个已知的基因型1菌株和26个已知的基因型2菌株来评估基质辅助激光解吸/电离飞行时间质谱仪（MALDI-TOF MS）使用质谱生物标记物准确鉴定Bovoculi菌株的能力。使用ClinProTools 3.0软件分析了质谱数据，并开发了六个模型来对菌株基因型进行分类，其准确度范围为90.6％-100％。最后，使用来自六个自动化模型的四个最特定于基因型的峰也显示出高峰强度，我们开发了一个定制模型（UNL辅助模型），该模型具有识别能力，验证和100％的基因型分类准确度。我们的结果表明，MALDI-TOF MS生物标记物可用于准确地区分牛油杆菌的基因型，而无需其他方法。我们使用来自六个自动化模型的四个最具基因型特异性的峰（也显示出高峰强度），开发了一个定制模型（UNL辅助模型），该模型具有对基因型分类的识别能力，验证和100％的分类精度。我们的结果表明，MALDI-TOF MS生物标记物可用于准确地区分牛油杆菌的基因型，而无需其他方法。我们使用来自六个自动化模型的四个最具基因型特异性的峰（也显示出高峰强度），开发了一个定制模型（UNL辅助模型），该模型具有对基因型分类的识别能力，验证和100％的分类精度。我们的结果表明，MALDI-TOF MS生物标记物可用于准确地区分牛油杆菌的基因型，而无需其他方法。