Microbiology General 824cbdce Lues maligna is caused by? A Borrelia B Leptospira C Brachyspira D Treponema High-Yield Explanation Ans. is 'd' i.e.,TreponemaLues maligna represents a rare form secondary syphilis ( caused by treponema pallidum).also known as 'malignant syphilis' or 'ulceronodular syphilis'.