Lei Qin,Fandan Meng,Haijuan He,Yong-Bo Yang,Gang Wang,Yan-Dong Tang,Mingxia Sun,Wenlong Zhang,Xuehui Cai,Shujie Wang

Front Vet Sci.2022 Jan 31;8:824349.doi: 10.3389/fvets.2021.824349. eCollection 2021.

Abstract

Trueperella pyogenes  causes disease in cattle, sheep, goats and swine, and is involved occasionally in human disease worldwide. Most reports implicating  T. pyogenes  have been associated with clinical cases, whereas no report has focused on pathogenicity of  T. pyogenes  in mouse models or precision-cut lung slice (PCLS) cultures from swine. Here, we isolated and identified a virulent, β-hemolytic, multidrug-resistant  T. pyogenes  strain named 20121, which harbors the virulence marker genes  fimA, fimE, nanH, nanP  and  plo . It was found to be highly resistant to erythromycin, azithromycin and medemycin. Strain 20121 was pathogenic in mouse infection models, displaying pulmonary congestion and inflammatory cell infiltration, partial degeneration in epithelial cells of the tracheal and bronchiolar mucosa, a small amount of inflammatory cell infiltration in the submucosa, and bacteria (>104 CFU/g) in the lung. Importantly, we used  T. pyogenes  20121 to infect porcine precision-cut lung slices (PCLS) cultures for the first time, where it caused severe bronchoconstriction. Furthermore, dexamethasone showed its ability to relieve bronchoconstriction in PCLS caused by  T. pyogenes  20121, highlighting dexamethasone may assist antibiotic treatment for clinical  T. pyogenes  infection. This is the first report of  T. pyogenes  used to infect and cause bronchoconstriction in porcine PCLS. Our results suggest that porcine PCLS cultures as a valuable 3D organ model for the study of  T. pyogenes  infection and treatment  in vitro.

Keywords: Trueperella pyogenes; bronchoconstriction; infection; porcine precision-cut lung slices; virulent.