The objectives were to quantify collagen content in nonlactating uninfected and Staphylococcus aureus–infected mammary glands and determine the relative abundance of collagen in different gland regions.
Materials and Methods
Mammary tissues that were previously collected from a mastitis-challenge trial were examined. Mammary tissues were collected along a vertical midline through each gland and included parenchymal tissues that were proximal to the gland cistern (cisternal parenchyma) and tissues near the abdominal wall (deep parenchyma) from each saline-infused (n = 18) and Staph. aureus–infused (n = 18) gland. Collagen was detected via picro-sirus red staining and visualized using polarized light for image acquisition and subsequent analysis.
Results and Discussion
Most interlobular collagen was associated with larger ducts and stromal tissues. Some collagen was intralobular and was mostly associated with these larger ducts but was also present in epithelial basement membranes. Staphylococcus aureus–infused glands contained more tissue area occupied by collagen than saline-infused glands (19.78 vs. 17.26 ± 1.19%). Additionally, parenchyma near the gland cistern contained more collagen than deep parenchyma (19.95 vs. 17.09 ± 1.19%). Results indicate that mastitis elicits the deposition of collagen in affected glands and that collagen abundance is affected by gland region.
Implications and Applications
Nonlactating mammary glands affected by Staph. aureus mastitis may have a greater amount of collagen, believed to be resulting scar tissue. We speculate that it may have long-term, and possibly irreversible, effects on glandular structure and, consequently, lifetime productivity.
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- Mastitis and its impact on structure and function in the ruminant mammary gland..10.1007/s10911-011-9231-3J. Mammary Gland Biol. Neoplasia. 2011; 16: 275-289
- Staphylococcus aureus chronic intramammary infection modifies protein expression of transforming growth factor beta (TGF-beta) subfamily components during active involution..https://doi.org/10.1016/j.rvsc.2013.11.00224290236Res. Vet. Sci. 2014; 96: 5-14
- Principles of wound healing..https://doi.org/10.1016/S0749-0739(17)30568-02691024Vet. Clin. North Am. Equine Pract. 1989; 5: 449-463
- Economic losses from and the national research program on mastitis in the United States..https://doi.org/10.3168/jds.S0022-0302(79)83213-0379057J. Dairy Sci. 1979; 62: 119-127
- Ultrastructural and associated observations on clinical cases of mastitis in cattle..https://doi.org/10.1016/0021-9975(73)90047-94761663J. Comp. Pathol. 1973; 83: 233-241
- Overview of wound healing and management..https://doi.org/10.1016/j.suc.2016.08.01327894427Surg. Clin. North Am. 2017; 97: 189-207
- Invited Review: Reevaluating how mastitis reduces milk yield: Discussion of competitive substrate utilization..https://doi.org/10.15232/aas.2019-01876Appl. Anim. Sci. 2019; 35: 408-415
- Staphylococcus aureus intramammary challenge in non-lactating mammary glands stimulated to rapidly grow and develop with estradiol and progesterone..https://doi.org/10.1186/s13567-018-0542-x29866164Vet. Res. 2018; 49: 47
- Apoptosis and proliferation in Staphylococcus aureus-challenged, nonlactating mammary glands stimulated to grow rapidly and develop with estradiol and progesterone..https://doi.org/10.3168/jds.2018-1549830415855J. Dairy Sci. 2019; 102 (a): 857-865
- Effects of Staphylococcus aureus intramammary infection on the expression of estrogen receptor α and progesterone receptor in mammary glands of nonlactating cows administered estradiol and progesterone to stimulate mammary growth..https://doi.org/10.3168/jds.2018-1549930639023J. Dairy Sci. 2019; 102 (b): 2607-2617
- Variations in breaking strength in healing wounds of young guinea pigs..https://doi.org/10.1097/00005373-196509000-000065826707J. Trauma. 1965; 5: 624-635
- Picrosirius staining plus polarization microscopy, a specific method for collagen detection in tissue sections..https://doi.org/10.1007/BF0100277291593Histochem. J. 1979; 11: 447-455
- Picrosirius red staining: A useful tool to appraise collagen networks in normal and pathological tissues..https://doi.org/10.1369/002215541454578725023614J. Histochem. Cytochem. 2014; 62: 751-758
- Histopathologic response of the bovine mammary gland to experimentally induced Staphylococcus aureus infection..7294468Am. J. Vet. Res. 1981; 42: 1351-1355
- Studies on bovine mastitis: Mastitis in heifers..Am. J. Vet. Res. 1941; 2: 18-34
- Bovine mastitis: A review..https://doi.org/10.3168/jds.S0022-0302(58)91071-3J. Dairy Sci. 1958; 41: 1141-1181
- Method for picrosirius red-polarization detection of collagen fibers in tissue sections..https://doi.org/10.1007/978-1-4939-7113-8_2628836216Methods Mol. Biol. 2017; 1627: 395-407
Spencer, G. R. 1949. The significance of hypersensitivity in bovine mastitis as determined by a study of its pathogenesis. PhD Diss. Univ. Wisconsin–Madison.
- Histopathology of staphylococcal mastitis in unbred dairy heifers..https://doi.org/10.3168/jds.S0022-0302(90)78715-22341639J. Dairy Sci. 1990; 73: 639-647
- Excess deposition of collagen in mammary glands of tamoxifen-treated Holstein heifers is associated with impaired mammary growth..https://doi.org/10.1016/j.domaniend.2018.05.00629894894Domest. Anim. Endocrinol. 2018; 65: 49-55
Accepted: July 20, 2020
Received: March 2, 2020
The authors declare no conflicts of interest.
© 2020 American Registry of Professional Animal Scientists. Published by Elsevier Inc. All rights reserved.