LACCEsS >Medicine From: Haemophilus and bordetella Sherris Medical Microbiology, 6e, 2014 Legend Chancroid. These penile ulcers are caused by Haemophilus ducreyi. In contrast to the ulcers of syphilis they are soft and painful (Reproduced with permission from Nester EW: Microbiology: A Human Perspective, 6th edition. 2009.) Date of download: 5/11/2016 Copyright o 2016 McGraw-Hill Education. All rights reservedDate of download: 5/11/2016 Copyright © 2016 McGraw-Hill Education. All rights reserved. Chancroid. These penile ulcers are caused by Haemophilus ducreyi. In contrast to the ulcers of syphilis they are soft and painful. (Reproduced with permission from Nester EW: Microbiology: A Human Perspective, 6th edition. 2009.) Legend: From: Haemophilus and Bordetella Sherris Medical Microbiology, 6e, 2014