Behdad Saba, Massudi Reza, Pakdel Abbas, Shekalgorabi Sahereh Joezy
Department of Animal Science, College of Agriculture, Science and Research Branch, Islamic Azad University, Tehran, 14778-93855, Iran.
Laser and Plasma Research Institute, Shahid Beheshti University, Tehran, 19839-69411, Iran.
Sci Rep. 2025 Jun 2;15(1):19239. doi: 10.1038/s41598-025-99421-x.
Mycobacterium Avium subspecies Paratuberculosis (MAP) causes Johne's disease or Paratuberculosis, a chronic, progressive intestinal disease in ruminants. The incidence and prevalence of Johne's disease are higher in dairy cattle herds because of intensive breeding and high production. Developing non-destructive diagnostic methods for early detection of this disease by simple sampling is paramount for breeding, economic, and health programs. Conventional methods are almost entirely destructive, have low accuracy, and are time-consuming. Near- infrared spectroscopy (NIRS) and Aquaphotomics can detect changes in biofluids and thus have the potential to diagnose the disease. This study aimed to investigate the diagnostic ability of NIRS and Aquaphotomics for Paratuberculosis in dairy cattle by milk sample. Milk samples from dairy cattle were collected in the NIR range (1300-1600 nm) 60 days before and 100-200 days after calving in two groups, positive and negative, using the three same consecutive ELISA test results of blood plasma and milk, as a reference test. The NIRS and Aquaphotomics methods in quadratic discriminant analysis (QDA) and support vector machine (SVM) models achieved high accuracy in detecting negative and positive groups. In internal validation, SVM and QDA models in 12 water absorbance bands had 100% accuracy. In external validation, milk samples with blood plasma ELISA reference test achieved 100% sensitivity, which is more accurate than milk ELISA as a reference test. The current study found that monitoring milk with NIR spectra provides an opportunity to analyze antibody levels indirectly via changes in water spectral patterns caused by complex physiological changes, such as the amount of antibodies related to Paratuberculosis by aquagram.
副结核分枝杆菌鸟亚种（MAP）可引发副结核病或约翰氏病，这是一种反刍动物的慢性、渐进性肠道疾病。由于集约化养殖和高产，约翰氏病在奶牛群中的发病率和患病率较高。开发通过简单采样进行早期疾病检测的非破坏性诊断方法对于育种、经济和健康计划至关重要。传统方法几乎完全具有破坏性，准确性低且耗时。近红外光谱（NIRS）和水相光组学可以检测生物流体中的变化，因此具有诊断该疾病的潜力。本研究旨在通过牛奶样本调查NIRS和水相光组学对奶牛副结核病的诊断能力。以血浆和牛奶的三项连续相同ELISA检测结果作为参考检测，将两组奶牛（阳性和阴性）在产犊前60天和产犊后100 - 200天收集的牛奶样本在近红外范围（1300 - 1600 nm）内进行检测。二次判别分析（QDA）和支持向量机（SVM）模型中的NIRS和水相光组学方法在检测阴性和阳性组时具有较高的准确性。在内部验证中，12个吸水带中的SVM和QDA模型准确率达到100%。在外部验证中，以血浆ELISA参考检测的牛奶样本灵敏度达到100%，比以牛奶ELISA作为参考检测更准确。当前研究发现，用近红外光谱监测牛奶提供了一个机会，可通过由复杂生理变化引起的水光谱模式变化间接分析抗体水平，例如通过水相图分析与副结核病相关的抗体量。
