The Innate Immunity in Bovine Mastitis: The Role of Pattern-Recognition Receptors

Abstract

Mastitis is the most costly disease for dairy farmers and industry, which are mainly caused by the entry of bacteria to the teat canal. Shortly after the entry of the invading bacteria, the innate immunity recognizes the invading pathogen through pattern recognition receptors and initiates the inflammatory response necessary to eliminate the invading bacteria. This initial inflammatory response releases cytokines and chemoattractants for the rapid and massive influx of neutrophils from the blood to the site of infection which form the first line of cellular defense against bacteria This article reviewed the role of the most recent knowledge regarding the innate immunity in bovine mastitis focusing in the two major mastitis pathogens: Escherichia coli and Staphylococcus aureus the S. aureus appears to mostly circumvent the host immune response, as the Toll-Like Receptors (TLRs) signaling pathways. The Intramammary Infections (IMIs) by this bacteria result in a very moderate host response with minimal observable innate immune response, which are related to well-known ability to this pathogen to establish chronic IMI. Otherwise, E. coli elicits a strong and earlier response, mainly through TLR4, that is associated with the severity of the mastitis and the clinical manifestation commonly observed in dairy cows infected with this pathogen. Suboptimal and dysfunctional mammary defenses may contribute to the development of severe acute inflammation or chronic mastitis that adversely affects the milk production and quality. Thus, a better understanding of mastitis pathogen interaction to the host may be useful for future control of mastitis.

Estudo comparativo das diferentes técnicas empregadas na contagem diferencial de leucócitos no leite

“…Em glândulas sadias, por exemplo, é constatado predomínio de leucócitos mononucleares (MN). Em contrapartida, quando infectada a população de leucócitos polimorfonucleares (PMN) aumenta drasticamente, predominando os neutrófilos (Sarikaya et al 2005, Souza et al 2012. Os PMN compõem a fração granulócita e são assim chamados devido à variabilidade de lóbulos nucleares quando na forma adulta e são compostas pelos: eosinófilos, basófilos e neutrófilos.…”

“…Portanto, considerando o aumento na proporção de neutrófilos durante o processo infeccioso (Souza et al 2012), a diferenciação das populações celulares presente no leite pode aprimorar o diagnóstico da mastite bovina. A contagem microscópica direta por esfregaços é rotineiramente utilizada para diferenciação das populações celulares, no entanto, demanda maior tempo para análise e apresenta baixa repetibilidade devido à subjetividade da avaliação (Koess & Hamann 2008).…”

Development of the Innate Immune Response and Influence of Colostrum Suckling in Calves

“…The cytokine IL-1beta is a potent mediator of inflammation and acts in synergism with IL-6 and TNF-alpha (Richards, 1998). It is possible that some mothers had mastitis, a common disease in dairy cows in the peripartum period and transferred the proinflammatory cytokines to their calves (Souza et al, 2012). In this case, these cytokines have no influence on the immunity of calves, since most of the calves in this study had undetectable reactions at 15 days (T5) of life, similar indeed to that found by Goto et al (1997) and Yamanaka et al (2003) and could direct us to determine the duration of the maternal immune component in the bloodstream of calves.…”

Infusão intramamária de Weissella confusa afeta a contagem de células somáticas e a contagem diferencial de leucócitos no leite

“…These findings showed the initial innate immune response PI of W and W+W10b substances given that innate defense mechanisms that are activated quickly upon exposure to bacteria (AITKEN et al, 2011). The resident leukocytes together with epithelial cells initiate the inflammatory response via release of chemoattractants for the rapid recruitment of PMNs to the site of infection and consequently the SCC increases (SOUZA et al, 2012).…”

“…The PRRs recognize specific patterns of microbial components that are conserved among pathogens known as Pathogen-Associated Molecular Patterns (PAMPs) (SOUZA et al, 2012). The PRRs, such as TollLike Receptors (TLRs) recognize a wide range of PAMPs and initiate an inflammatory response with a rapid recruitment of PMNs to the mammary gland and consequently the SCC increases.…”