The effect of staphylococcal mastitis including resistant strains on serum procalcitonin, neopterin, acute phase response and stress biomarkers in Holstein dairy cows

Abstract

Staphylococcal mastitis (SM) is a frequent disease in the dairy cattle that is costly to treat. This study aimed to investigate the alterations in the levels of procalcitonin (PCT), neopterin (NPT), haptoglobin (HP), serum amyloid A (SAA), proinflammatory cytokines (IL-1β, IL-8, TNF-α, IF-γ) and oxidative stress (OS) biomarkers in Holstein dairy cows with SM under field conditions. In addition, we also evaluated the role of examined biomarkers in disease pathogenesis and their use as diagnostic biomarkers for the disease in dairy cows. Fifty-three dairy cows with SM, including those with infections caused by Staphylococcus aureus (n = 42) and methicillin resistant S. aureus (MRSA) (n = 11) were selected for this study. In addition, 20 healthy dairy cows were enrolled as a control group. Higher serum levels of PCT, NP, IL-1β, IL-8, TNF-α, IF-γ, HP and SAA and a state of OS was detected in SM group in comparison with the controls. Moreover, the levels of all examined biomarkers in mastitic cows with S. aureus when compared with those infected with MRSA was not significantly different. All examined biomarkers demonstrated a significant degree of discrimination between SM cows and healthy controls (the area under the curve (AUC) ranged from 83.6 for SAA to 100 for PCT). Our study showed that SM in dairy cows was associated with substantial changes in serum PCT, NPT, Acute phase proteins (APPs), proinflammatory cytokines, and OS levels. This study demonstrates that clinical examination in tandem with quantification of PCT, NPT, APPs and cytokines, OS biomarkers could be a useful assessment tool for SM in dairy cows.

Can Procalcitonin Be Dosed in Bovine Milk Using a Commercial ELISA Kit?

“…In human medicine, PCT has been used as a marker for sepsis diagnosis, but also for controlling the course of the disease, and for antibiotic stewardship [14]. The same use has also been investigated in veterinary medicine [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33]. Although there are promising results from previous mentioned studies, in veterinary medicine PCT can be assessed only using ELISA kits from different manufacturers conceived for research purposes.…”

“…In a study from 2016, a human ELISA kit was employed to detect serum PCT concentrations in neonatal calves affected by colibacillosis, but no validation data were reported [30]. Bonelli et al [26] measured the plasma PCT concentration in calves using another bovine ELISA kit (Mybiosource, San Diego, CA, USA), showing a partial validation, while El-deeb et al [32,33] used the same ELISA kit for measuring plasma PCT concentration in calves without showing data on validation. A recent study evaluated PCT levels in serum samples of cows affected by Staphylococcal mastitis [33].…”

“…Bonelli et al [26] measured the plasma PCT concentration in calves using another bovine ELISA kit (Mybiosource, San Diego, CA, USA), showing a partial validation, while El-deeb et al [32,33] used the same ELISA kit for measuring plasma PCT concentration in calves without showing data on validation. A recent study evaluated PCT levels in serum samples of cows affected by Staphylococcal mastitis [33]. Unfortunately, no information was given by the authors regarding their validation analysis.…”

“…In both cases PCT plasma concentrations were significantly higher in sick calves compared with healthy ones. A very recent study found that serum PCT was higher in cows affected by subclinical mastitis [33].…”

“…During bacterial infections, plasmatic PCT levels increase because lipopolysaccharides (LPS) and the inflammatory cytokines specific to bacterial infection, such as interleukin-1 beta (IL-1β), IL-6 and tumor necrosis factor-alpha (TNF-α), stimulate the upregulation of the expression of the CALC-1 gene in multiple tissues, leading to a massive production of PCT from many tissues [12,14]. In veterinary medicine, PCT has been investigated as a biomarker of bacterial infections in adult horses [15][16][17][18][19][20][21][22], foals [23][24][25], and dogs [26][27][28][29], while few studies have been conducted in ruminants [30][31][32][33]. Two papers evaluated plasma PCT concentrations in septic neonatal calves [30,31], and in feedlot calves (4-12 months old) with respiratory disease [32].…”