J Vet Sci.  2019 May;20(3):e28. 10.4142/jvs.2019.20.e28.

Histopathological and microbiological findings in buffalo chronic mastitis: evidence of tertiary lymphoid structures

• Restucci B
• Dipineto L
• Martano M
• Balestrieri A
• Ciccarelli D
• Russo TP
• Varriale L
• Maiolino P

• KMID: 2448712
• DOI: http://doi.org/10.4142/jvs.2019.20.e28

Abstract

Buffalo mastitis is an important economic problem in southern Italy, causing qualitative/quantitative alterations in milk and resulting in economic losses due to the sub-clinical course and chronic evolution. We investigated 50 udders of slaughtered buffaloes and subjected them to effectual microbiological screening to evaluate macro and microscopic mammary gland changes, immune-characterize the cell infiltrates, and compare the degree of tissue inflammation with somatic cell counts. Numerous Gram-positive and Gram-negative bacteria were isolated from all samples, majority of which were environmental mastitis pathogens. Histological features referable to chronic mastitis were observed in 92% udders. Lymphocytes, plasma cells and macrophages were found to evolve into aggregates in 48% udders, which often organized to form tertiary lymphoid structures (TLSs). A predominance of interstitial CD8+ over CD4+ lymphocytes and, in TLSs, scattered CD8+ lymphocytes in the mantle cells and CD79+ lymphocytes in germinal centers, were evidenced. Environmental pathogens are known to persist and cause chronic inflammatory changes in buffaloes, where CD8+ lymphocytes play an important role by controlling the local immune response. Moreover, the TLSs evidenced here for the first time in buffalo mastitis, could play a role in maintaining immune responses against persistent antigens, thereby contributing in determining the chronic course of mastitis.

Keyword

Chronic mastitis; buffalo; histopathology; microbiology; tertiary lymphoid structures

MeSH Terms

Animals
Buffaloes*
Cell Count
Female
Germinal Center
Gram-Negative Bacteria
Inflammation
Italy
Lymphocytes
Macrophages
Mammary Glands, Animal
Mammary Glands, Human
Mass Screening
Mastitis*
Milk
Plasma Cells