Symposium review: Features of Staphylococcus aureus mastitis pathogenesis that guide vaccine development strategies

Abstract

Bovine mastitis affects animal health and welfare and milk production and quality, and it challenges the economic success of dairy farms. Staphylococcus aureus is one of the most commonly found pathogens in clinical mastitis but it also causes subclinical, persistent, and difficult-to-treat intramammary infections. Because of the failure of conventional antibiotic treatments and increasing pressure and concern from experts and consumers over the use of antibiotics in the dairy industry, many attempts have been made over the years to develop a vaccine for the prevention and control of Staph. aureus intramammary infections. Still, no commercially available vaccine formulation demonstrates sufficient protection and cost-effective potential. Multiple factors account for the lack of protection, including inadequate vaccine targets, high diversity among mastitis-provoking strains, cow-to-cow variation in immune response, and a failure to elicit an immune response that is appropriate for protection against a highly complex pathogen. The purpose of this review is to summarize key concepts related to the pathogenesis of Staph. aureus, and its interaction with the host, as well as to describe recent vaccine development strategies for prevention and control of Staph. aureus mastitis.

Case report: characterization of a persistent, treatment-resistant, novel Staphylococcus aureus infection causing chronic mastitis in a Holstein dairy cow

“…Many different strains of S. aureus exist that are capable of causing mastitis in dairy cattle. Variations in mastitis-causing strains include differences in the genotypic expression of virulence factors, biofilm production, cellular infiltration, and antimicrobial activity [27]. Comparison of an infection by SA1428 and SA Newbould highlights the phenotypic variation between strains that can be observed, both in terms of host immune cell response and response to antibiotic treatment; Newbould being successfully cleared and SA1428 persisting.…”

In vivo model to study the impact of genetic variation on clinical outcome of mastitis in uniparous dairy cows

“…For decades, mastitis has caused large-scale economic losses worldwide in dairy farming due to treatment costs, discarded milk, reduced milk yield and increased culling rates [1][2][3][4][5][6]. A recent study from Canada estimated costs on typical dairy farms to be 662 Canadian Dollars per milking cow per year, in which nearly half of the costs were associated with subclinical mastitis [7].…”

“…Staphylococcus aureus (S. aureus) is one major pathogen causing SCM or mild cases of CM in dairy cows [16]. Due to intermittent shedding, S. aureus is difficult to detect, and treatment of affected animals is often futile, since S. aureus IMI tends to persist within the udder and causes chronic cases of SCM [1,6,17]. In the dairy industry, CM and SCM are the major reasons for antimicrobial usage [18,19].…”

Analysis of virulence traits of Staphylococcus aureus isolated from bovine mastitis in semi-intensive and family dairy farms

“…S. aureus internalization into bMECs occurs mainly by a zipper-like mechanism involving fibronectin-binding protein (FnBP) from S. aureus and fibronectin and α5β1 integrin host cell receptors [ 5 6 ]. Furthermore, the establishment and development of mastitis depend on environmental factors, such as geographical location, climate, production systems, and good management practices as well as virulence and bacterial pathogenicity [ 7 ].…”