摘要

由猪痢疾短螺旋体（猪痢疾短螺旋体）引起的猪痢疾（SD）的治疗使用抗生素如大环内酯，林可酰胺和截短侧耳素来进行，从而导致选择耐药菌株。称为BH718的多重抗药性猪痢疾短螺旋体菌株的全基因组测序属于序列类型（ST）83，揭示了在小的1724-bp转座子MTnSag1上存在林可酰胺抗性基因lnu（C）。该菌株还包含23S rRNA基因中第2058位的A至T取代（A2058T），已知其与B.hyodysenteriae中的大环内酯和林可酰胺抗性相关。其他菌株的检测表明，与缺乏lnu（C）的菌株相比，含有lnu（C）的那些菌株表现出林可霉素的最小抑制浓度（MIC）（MIC≥64mg/ L），即使它们也含有A2058T突变。已报道的23S rRNA基因和核糖体蛋白L3中的突变不能解释对截短侧耳素的抗性。该研究表明，猪痢疾短螺旋体能够获得赋予抗生素抗性的移动遗传元件。

Treatment of Swine Dysentery (SD) caused by Brachyspira hyodysenteriae (B. hyodysenteriae) is carried out using antimicrobials such as macrolides, lincosamides and pleuromutilins leading to the selection of resistant strains. Whole genome sequencing of a multidrug-resistant B. hyodysenteriae strain called BH718 belonging to sequence type (ST) 83 revealed the presence of the lincosamide resistance gene lnu(C) on the small 1724-bp transposon MTnSag1. The strain also contains an A to T substitution at position 2058 (A2058T) in the 23S rRNA gene which is known to be associated with macrolide and lincosamide resistance in B. hyodysenteriae. Testing of additional strains showed that those containing lnu(C) exhibited a higher minimal inhibitory concentration (MIC) of lincomycin (MIC ≥ 64 mg/L) compared to strains lacking lnu(C), even if they also harbor the A2058T mutation. Resistance to pleuromutilins could not be explained by the presence of already reported mutations in the 23S rRNA gene and in the ribosomal protein L3. This study shows that B. hyodysenteriae has the ability to acquire mobile genetic elements conferring resistance to antibiotics.

https://www.sciencedirect.com/science/article/pii/S0378113517312130