Ultra-performance liquid chromatography-quadrupole-time of flight mass spectrometry MSE-based untargeted milk metabolomics in dairy cows with subclinical or clinical mastitis

Abstract

In this study, a novel metabolomics technique based on ultra-performance liquid chromatography-quadrupole-time of flight mass spectrometry in the MS mode was used to investigate the milk metabolomics of healthy, subclinical, and clinical mastitis cows, which were classified based on somatic cell count and presentation of clinical symptoms. Meanwhile, univariate and multivariate statistical analyses were performed to identify the significant differences across the 3 groups. Compared with healthy milk samples, less glucose, d-glycerol-1-phosphate, 4-hydroxyphenyllactate, l-carnitine, sn-glycero-3-phosphocholine, citrate, and hippurate were detected in the clinical mastitic milk samples, whereas less d-glycerol-1-phosphate, benzoic acid, l-carnitine, and cis-aconitate were found in the subclinical mastitic milk samples. Meanwhile, the milk concentration of arginine and Leu-Leu increased in both the clinical and subclinical mastitis groups. Besides, less 4-hydroxyphenyllactate, cis-aconitate, lactose, and oxoglutarate were detected in the clinical than the subclinical mastitic milk samples, whereas the abundance of some oligopeptides (Leu-Ala, Phe-Pro-Ile, Asn-Arg-Ala-Ile, and Val-Phe-Val-Tyr) increased by over 7.95-fold. Our results suggest that significant variations exist across healthy and mastitis cows. The current metabolomics approach will help in better understanding the pathobiology of mastitis, although clinical validation will be required before field application.

The Effect of Lipopolysaccharide-Induced Experimental Bovine Mastitis on Clinical Parameters, Inflammatory Markers, and the Metabolome: A Kinetic Approach

“…The liver and the udder are primary sites for fatty acid synthesis, and it is hence possible that the decreased citrate levels can be due to hampered liver or udder function as a consequence of the inflammatory conditions induced by LPS infusion. In line with the findings presented here, it was shown in a previous study that clinical mastitis was associated with a decrease of citrate in the milk ( 19 ), and decreased citrate levels have also been observed in subclinical mastitis ( 58 ). Our findings are thus consistent with these latter studies and, based on these studies together, citrate can be considered as a potential biomarker that can be useful in the monitoring of mastitis.…”

Worldwide Variation in Human Milk Metabolome: Indicators of Breast Physiology and Maternal Lifestyle?

“…As shown in a study of US women, the levels of milk 2-oxoglutarate in women feeding term infants typically decline within one month of birth [ 20 ]. Of note, lower 2-oxoglutarate levels have been detected in the milk of dairy cows with mastitis (breast duct infection), which is interpreted to be a function of greater consumption of this TCA cycle intermediate by resident microbiota or infecting microbes [ 3 , 29 ]. Mastitis and subclinical mastitis are common infections postpartum in industrialized countries [ 30 ], which offers another explanation for 2-oxoglutarate consumption and lower milk concentrations in US, Australian, and Norwegian women.…”

Metabotypes with elevated protein and lipid catabolism and inflammation precede clinical mastitis in prepartal transition dairy cows

“…Traditional CM indicator studies focus on indicators in milk at the onset of CM, including SCC counts, serum proteins, enzymes, electrolytes, degradation products of milk proteins, and acute phase proteins (Lai et al, 2009; Sundekilde et al, 2013). In recent years, this research has been extended to metabolomics approaches to discover indicators in infected bovine milk, which can aid in the detection, differential diagnosis of CM based on pathogen, and to examine the pathophysiology of CM (Mansor et al, 2013; Thomas et al, 2016; Xi et al, 2017). Dairy cows are most susceptible to naturally occurring CM within the first weeks after calving; however, the infection may occur during the close-up period or around calving (Rollin et al, 2015), when milk sample are not available (Hurley and Theil, 2011).…”