Facultad de Estudios Superiores Iztacala, UNAM,Av. De Los Barrios 1, Los Reyes Iztacala, 54090 Tlalnepantla, Edo de México, Mexico.
Centro de Investigaciones en Ciencias Microbiológicas, BUAP, Apdo, 1622, Puebla, 72560, Puebla, Mexico.
FEMS Microbiol Lett. 2023 Jan 17;370. doi: 10.1093/femsle/fnad048.
Actinobacillus seminis is the causal agent of epididymitis and has other effects on the reproductive tracts of small ruminants and bovines. This bacterium causes infection when luteinizing (LH) or follicle-stimulating hormones increase, and hosts reach sexual maturity. LH induces female ovulation and male testosterone production, suggesting that these hormones affect A. seminis pathogenicity. In the present study, we evaluated the effect of testosterone (1-5 ng/ml) or estradiol (5-25 pg/ml) added to culture medium on the in vitro growth, biofilm production, and adhesin expression of A. seminis. Estradiol does not promote the growth of this bacterium, whereas testosterone increased A. seminis planktonic growth 2-fold. Both hormones induced the expression of the elongation factor thermo unstable (EF-Tu) and phosphoglycerate mutase (PGM), proteins that A. seminis uses as adhesins. Estradiol (5 or 10 pg/ml) decreased biofilm formation by 32%, whereas testosterone, even at 5 ng/ml, showed no effect. Both hormones modified the concentrations of carbohydrates and eDNA in biofilms by 50%. Amyloid proteins are characterized by their capacity to bind Congo red (CR) dye. Actinobacillus seminis binds CR dye, and this binding increases in the presence of 5-20 pg/ml estradiol or 4 ng/ml testosterone. The A. seminis EF-Tu protein was identified as amyloid-like protein (ALP). The effect of sexual hormones on the growth and expression of virulence factors of A. seminis seems to be relevant for its colonization and permanence in the host.
精氨酸杆菌是附睾炎的病原体，对小反刍动物和牛的生殖道也有其他影响。当促黄体激素（LH）或卵泡刺激素增加，宿主达到性成熟时，这种细菌会引起感染。LH 诱导雌性排卵和雄性睾酮的产生，这表明这些激素会影响 A. seminis 的致病性。在本研究中，我们评估了培养基中添加睾酮（1-5ng/ml）或雌二醇（5-25pg/ml）对 A. seminis 体外生长、生物膜生成和黏附素表达的影响。雌二醇不会促进该细菌的生长，而睾酮则使 A. seminis 浮游生长增加了 2 倍。这两种激素都诱导了伸长因子热不稳定（EF-Tu）和磷酸甘油酸变位酶（PGM）的表达，这两种蛋白都是 A. seminis 作为黏附素使用的。雌二醇（5 或 10pg/ml）使生物膜形成减少了 32%，而睾酮即使在 5ng/ml 时也没有效果。这两种激素都使生物膜中的碳水化合物和 eDNA 浓度降低了 50%。淀粉样蛋白的特征是其结合刚果红（CR）染料的能力。精氨酸杆菌结合 CR 染料，并且这种结合在存在 5-20pg/ml 雌二醇或 4ng/ml 睾酮时增加。A. seminis 的 EF-Tu 蛋白被鉴定为淀粉样蛋白样蛋白（ALP）。性荷尔蒙对 A. seminis 毒力因子的生长和表达的影响似乎与其在宿主中的定植和持久存在有关。
