Concentration of Acute Phase Proteins in Milk: A New Tool for Mastitis Diagnosis
Felipe Morales Dalanezi, Sâmea Fernandes Joaquim, Rodrigo Costa da Silva, Elizabeth Moreira dos Santos Schmidt and Helio Langoni*
Department of Veterinary Hygiene and Public Health, School of Veterinary Medicine and Animal Sciences, Brazil
Submission: February 28 , 2017; Published: March 22, 2017
*Corresponding author: HelioLangoni, Department of Veterinary Hygiene and Public Health, School of Veterinary Medicine and Animal Sciences, Universidade Estadual Paulista, Botucatu, São Paulo State, Brazil, Email: [email protected]
How to cite this article: Felipe M D, Sâmea F J, Rodrigo C d S, Elizabeth M d S S , Helio L. Dairy and Vet Sci J. 2017; 1(3): 555565. DOI: 10.19080/JDVS.2017.01.555565
Mastitis is a disease of the mammary gland, caused by pathogens like bacteria, fungi, virus, and algae. Bacteria are the principal agents, and the infection caused by then can be classified in contagious and environmental. Each of them present’s different and specific characteristics and control measures. The disease is responsible for high economic losses in the dairy production. In this way, it is necessary to minimize the losses. To attenuate the losses of the dairy producers, a precise and quickly diagnosis of mastitis is necessary. Currently, the tests used in dairy science are not so efficient, present’s low sensitivity, or provide low help to the veterinarian and/or producer to control mastitis on time to avoid new cases and solve those in course. Acute phase proteins maybe are produced in mammary gland and have a change on its concentration. The method to measure of these proteins can be implanted in a dipping machine like SCC, and help the professionals to determine which cow needs the treated. The aim of this paper is to explain how the APPs can be used as a new and better tool for the mastitis diagnosis.
Mastitis presents a significant worldwide impact in milk production, showing an annual cost at least US$ 2,000,000,000 to dairy producers of United States. The major part of amount is related to the reduction of milk production (US$115/cow/year), treatment cost (US$50/cow/year), and animal mortality (US$14/cow/year), totalizing US $179/cow/year with clinical mastitis . Mastitis is characterized by a multiple etiology mammary gland infection, being more frequently caused by bacteria , that triggers an inflammatory response . Mastitis can be classified as subclinical or clinical mastitis. The clinical form of mastitis is characterized by abnormal milk production, and can presents mammary gland alterations or systemic signs [4,5]. The subclinical mastitis present an inflammatory cell mobilization to the mammary gland, causing an increase on somatic cell count (SCC) [6,7].
Nowadays, new diagnostics tools are available, and aim to facilitate the mastitis diagnostic as well as to analyses the disease prognosis . The acute phase proteins (APP) are potential biomarkers of inflammation produced in the liver and others extra-hepatics tissues like mammary gland, presenting a promising future to aid the diseases diagnosis in veterinary medicine . During the inflammatory, APPs can improve the concentration to 100-fold . These proteins can be detected in
various body fluids, and blood , APPs is produced in specifics organs and tissues which provide local inflammation . However, APPs produced and released by the mammary gland can be more specific and sensitive for mastitis than the blood ones . In bovines, the principal APPs are the Haptoglobin (Hp), Lipo polysaccharides binding protein (LBP), Serum A Amyloid (SAA) and α1-acid glycoprotein (AGP) . The APPs can be classified as major, moderate and minor, according to the inflammatory response. The four APPs aforementioned are major APPs. Mammary associated Serum Amiloid A isoform 3 (M-SAA3) and C-Reative Proteins (CRP) are important APPs found in milk. They have been measured in milk as biomarkers of mastitis [14,15].
The SAA belong to a big family of proteins known as one of the most reactive APPs . The major part of the isoforms of SAA is produced in the liver, and unleashed at the bloodstream . The isoform 3 of the SAA (M-SAA3) identified in the bovine milk is produced by mammary cells and acts combating the local inflammation in the udder . Health cows presents an increase of the M-SAA3 production for the epitelial cells of the teat, when stimulated with prolactin, however this increase is not followed by the production of SAA. It demonstrates that the M-SAA3 is the
most important isoform to the mammary gland .
It was also observed that M-SAA3 is a bio indicator of mastitis
more trustworthy than the Hp, with a better correlation to the
inflammation of the mammary gland . M-SAA3 stimulates the
innate response of the immunity system of the udder, and also
has antibacterial action against Escherichia coli, Streptococcus
uberis and Pseudomonas aeroginosa . Cows experimentally
infected with Staphylococcus aureus presented an increase to
the M-SAA3 concentration earlier in milk than blood . Extra
mammary infections can elevate the serum SAA concentration,
but does not interfere to the M-SAA3 concentration in milk. Thus,
this isoform is not influenced by new inflammations .
As SAA, CRP is also produced in the liver and unleashed
in the bloodstream [22-24]. CRP decreases tissue damage,
destroys pathogens, and assists tissue regeneration [24,25].
Despite being considerate a minor APP due the small variation
in blood concentration during inflammatory process, in mastitis
cases in dairy cows the serum concentration of CRP observed
is, approximately, 1083ng/mL, while in health cows it is 82ng/
mL . In milk of cows with clinical mastitis (SCC greater than
200,000), the mean concentration is 32.64ng/mL, and ranges
from 1.8 to 172.47ng/mL . Moreover, it was demonstrated
that the CRP does not follow the variation in the SCC of the
milk. In this way, the CRP concentration is more sensitive to the
mammary infections than the SCC [10,15,26]. It is believed that
the high range observed in the concentration of this APP should
be caused by the different types of causative agents of clinical
mastitis, and highlights the importance of this protein to the
diagnosis of mastitis caused by different pathogens.
The determination of these proteins (M-SAA3 and CRP) can
be performed by the immunoassay technique, which measures
during the dipping? It was demonstrated that the clinical
mastitis caused by different pathogens can cause a greater or a
smaller increase in the concentration of the APP in the milk .
In the same work, the authors also observed that several mastitis
generates a large liberation of these proteins once compared
with mild or moderate level mastitis. Therefore, it is possible
that the pathogens causing severe mastitis stimulate a higher
liberation of these proteins.
More studies are necessary to determine the concentration
of these APPs and the correlation of these concentrations with
the cause of mastitis. In this way, new methods based in the APPs
in milk would improve the mastitis diagnosis and it will be the
future of the diagnosis making the time-consuming techniques
like microbiologic culture less needful.