Role of sortase A in the pathogenesis of Staphylococcus aureus‐induced mastitis in mice. Issue 1 (22nd January 2014)

• Record Type: Journal Article
• Authors: Chen, Fuguang; Liu, Bingrun; Wang, Dacheng; Wang, Lin; Deng, Xuming; Bi, Chongwei; Xiong, Ying; Wu, Qianchao; Cui, Yiwen; Zhang, Yong; Li, Xinlan; Wang, Ying; Liu, Bo; Cao, Yongguo
• Is Part Of: FEMS microbiology letters. Volume 351:Issue 1(2014:Feb.)
• Page Start: 95
• Page End: 103
• Publication Date: 2014-01-22
• Subjects: Microbiology -- Periodicals; 579
• DOI: 10.1111/1574-6968.12354
• Languages: English
• ISSNs: 0378-1097

Abstract

<abstract abstract-type="main" id="fml12354-abs-0001"> <title>Abstract</title> <p>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 <italic>Staphylococcus aureus</italic>, we constructed a mutant strain, ∆SrtA, by genetic techniques and identified its functions in a <italic>S. aureus</italic>‐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 <italic>S. aureus</italic> 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 <italic>S. aureus</italic>‐induced mastitis in mice. It appears that the <italic>srtA</italic> mutant affected the attachment of <italic>S. aureus</italic> 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.</p> </abstract>