Now, Leptospira is a tiny spiral bacteria, that stains poorly with Gram staining, because it doesn't retain the Gram dyes well, so it's classically considered gram-negative.

钩端螺旋体是一种细小的螺旋形病菌，革兰氏染色效果较差，因为它不能很好地保留染色剂，所以通常认为它是一种革兰氏阴性菌。