Analysis of the Frequency of Single Nucleotide Polymorphisms in the Innate Immune Response Genes Nramp1 and Bmap-28 Related to Resistance or Susceptibility to Bovine Mastitis

Abstract

Infectious bovine mastitis is an infection of mammary gland responsible great losses to dairy farming, resulting in negative impacts on the quantity and quality of milk produced. Genetic factors may be related to resistance or intensification of the inflammatory condition. Among them, the bovine myeloid antimicrobial peptide 28 gene (Bmap-28) and the natural resistance associated macrophage protein 1 gene (Nramp1) stand out because they can be used as genetic markers in dairy cattle breeding programs. The aim of this study was to analyze the immunogenetic profile in herds from the dairy basin of the state of Pernambuco in Northeastern Brazil, using these markers previously established in the literature. For this, the partial sequencing of the genes Bmap-28 and Nramp1 was performed. The study covered 54 animals, regardless of sex or age. For Bmap-28, two genotypes were found, GG (76%) and GC (24%). Both profiles are considered susceptible to intramammary infection. On the other hand, Nramp1 immunogenotyping revealed three distinct profiles, GG (11%), GC (48%) and CC (41%), of which only the GG genotype configures resistance to mastitis. The immunogenetic scenario detected suggests that the local herd is prone to intramammary infection, which is corroborated by the high prevalence (65.2%) of mastitis in the Agreste region of Pernambuco State.