Biomedical Engineering Reference
In-Depth Information
Erysipelothrix contains one infectious species;
Erysipelothrix rhusiopathiae, the cause of erysipeloid, a type of cellulitis
(subcutaneous infection). Students should not confuse erysipeloid with the
similar-sounding disease, erysipelas. Both erysipeloid and erysipelas produce
cellulitis. Erysipelas is more common and, potentially, a more serious disease
than erysipeloid. Erysipelas is caused by members of Genus Streptococcus
(Class Bacilli, Chapter 12). Two additional similar-sounding skin conditions
are erythrasma, characterized by brown scaly skin patches, caused by
Corynebacterium minutissimum (Class Actinobacteria, Chapter 14), and ery-
thema infectiosum, caused by Parvovirus B19 (Chapter 40). All four skin
conditions are associated with reddened skin, and all four diseases take their
root from the Greek, “erusi,” meaning red.
Chapter 12, Class Bacilli plus Class Clostridia
Chapter 11, Mollicutes
The term “bacillary”
is misleading. You might think that the adjective “bacillary” would
be restricted to members of Class Bacilli, its subclasses, and Genus Bacillus.
It seldom does. The word “bacillus” has its root in Latin, from “baculum”,
a rod or staff, so the name has been applied to the second term in the
bionomial name of bacteria that do not belong to Class Bacilli.
An example of a species with “bacilla” in its name, that is not a member
of Class Bacilli is Bartonella bacilliformis (the cause of verruga peruana).
Examples of genera with “bacillus” in their name, that are not members of
Class Bacilli, are: Actinobacillus and Streptobacillus. Genus Streptobacillus
(Class Fusobacteria, Chapter 10), is a terminologic catastrophe, as it is not a
sister genus to Streptococcus, and it is not a member of Class Bacilli.
The subclasses of Class Bacilli were assigned based on phylogeny, not
on morphology. Therefore, there are members of Class Bacilli that are not
rod-shaped (e.g., Genus Staphylococcus and Streptococcus).
Furthermore, there are diseases containing the term “bacillary” that are
not caused by members of Class Bacilli. These include bacillary angiomato-
sis (caused by Bartonella quintana and Bartonella henselae), and bacillary
dysentery (caused by four different Shigella species and by Yersinia
enterocolitica).
Chapter 12, Class Bacilli plus Class Clostridia
Listeria monocytogenes
is the organism that causes listeriosis. Listeriosis should not be confused
with the similar-sounding disease, leptospirosis (Spirochaetae, Chapter 9).
Chapter 13, Chlamydiae
Readers should not confuse trachoma with
inclusion conjunctivitis, as each disease is caused by distinct variants of the
same species (Chlamydia trachomatis). Trachoma is contracted by exposure
to eye secretions from people with trachoma. Inclusion conjunctivitis is
caused by ocular exposure to secretions from the sexually transmitted
infection.
Chapter 13, Chlamydiae
Chlamydia trachomatis mayalsocauselym-
phogranuloma venereum, a disease that usually presents as swollen lymph
nodes in the groin. The lymph nodes often have draining abscesses. The disease
