title: Role of sortase A in the pathogenesis of Staphylococcus aureus-induced mastitis in mice.
abstract: Sortase A (SrtA), a transpeptidase, anchors surface proteins with an LPXTG-motif sorting signal to the cell envelope. To determine the role of SrtA in the pathogenesis of Staphylococcus aureus, we constructed a mutant strain, ∆SrtA, by genetic techniques and identified its functions in a S. aureus-induced mastitis mouse model. The histological and myeloperoxidase (MPO) level results showed that the ∆SrtA strain attenuated the inflammatory reaction in the mammary tissue of mice compared with wild-type S. aureus challenge. Additionally, the ELISA results showed that the ∆SrtA strain impaired the induction of pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6), and the Western blot results showed that the mutant strain blocked the activation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinases (MAPKs) by attenuating the degradation and phosphorylation of signaling pathway molecules such as IκBα, p65 and p38. These results suggest that SrtA is a key virulence factor in the pathogenesis of S. aureus-induced mastitis in mice. It appears that the srtA mutant affected the attachment of S. aureus to host cells, thus attenuating the activation of the NF-κB and MAPK signaling pathways, which regulated the expression of pro-inflammatory cytokines and decreased the susceptibility to mastitis.
authors: College of Animal Science, Jilin University, Changchun, China.
authors: Fuguang
authors: F
authors: Chen
authors: Bingrun
authors: B
authors: Liu
authors: Dacheng
authors: D
authors: Wang
authors: Lin
authors: L
authors: Wang
authors: Xuming
authors: X
authors: Deng
authors: Chongwei
authors: C
authors: Bi
authors: Ying
authors: Y
authors: Xiong
authors: Qianchao
authors: Q
authors: Wu
authors: Yiwen
authors: Y
authors: Cui
authors: Yong
authors: Y
authors: Zhang
authors: Xinlan
authors: X
authors: Li
authors: Ying
authors: Y
authors: Wang
authors: Bo
authors: B
authors: Liu
authors: Yongguo
authors: Y
authors: Cao
keywords: 
  Staphylococcus aureus
  ; Sortase A; inflammatory response; mastitis; mitogen-activated protein kinases; nuclear factor-κB