Fig. 1

Mastitis was induced by oral gavage of sf-GFP-S. maltophilia in mice. After the mice were treated with 10¹⁰ CFU S. maltophilia for one week, the mammary gland tissues were collected and their inflammatory indicators were detected. A H&E staining of mammary tissue in control and S. maltophilia gavage mice. The S. maltophilia gavage group showed incomplete mammary gland follicular structure and inflammatory cell infiltration. B Histopathological scores of mammary gland tissues in control and S. maltophilia gavage mice. C and D Expression of inflammatory cytokines TNF-α and IL-1β in mammary gland tissues. E MPO activity in mammary tissues. F Significant activation of p-38/MAPK and NF-κB signaling pathways and significant upregulation of p-p38, p-p65 protein expression in mammary tissue of mice after S. maltophilia gavage. The data are presented as mean ± SD. One-way analysis of variance was performed for statistical analysis. ^*P < 0.05, ^**P < 0.01 and ^***P < 0.001 indicate significance from each group. ns, no significance