Page 125 - Review of Medical Microbiology and Immunology ( PDFDrive )

mebooksfree.com
mebooksfree.com
mebooksfree.com

mebooksfree.com mebooksfree.com mebooksfree.com are often called “metastatic abscesses” because they occur mebooksfree.com
mebooksfree.com
mebooksfree.com
mebooksfree.com
mebooksfree.com
mebooksfree.com
PART II Clinical Bacteriology
114
by the spread of bacteria from the original site of infection,
often in the skin.

Staphylococcus aureus: Toxin-Mediated Diseases
(1) Food poisoning (gastroenteritis) is caused by inges-
tion of enterotoxin, which is preformed in foods and hence
has a short incubation period (1–8 hours). In staphylococ-
mebooksfree.com mebooksfree.com mebooksfree.com hypotension; a diffuse, macular, sunburn-like rash that mebooksfree.com
mebooksfree.com
mebooksfree.com
cal food poisoning, vomiting is typically more prominent
than diarrhea.
(2) Toxic shock syndrome is characterized by fever;
goes on to desquamate; and involvement of three or more
of the following organs: liver, kidney, gastrointestinal tract,
central nervous system, muscle, or blood.
(3) Scalded-skin syndrome is characterized by fever,
large bullae, and an erythematous macular rash. Large
areas of skin slough, serous fluid exudes, and electrolyte
imbalance can occur. Hair and nails can be lost. Recovery
usually occurs within 7–10 days. This syndrome occurs
most often in young children.
mebooksfree.com
mebooksfree.com
mebooksfree.com mebooksfree.com mebooksfree.com Kawasaki disease (KD) is a disease of unknown etiology mebooksfree.com
FIGURE 15–7
Carbuncle. A carbuncle is a multiheaded
Staphylococcus aureus: Kawasaki Disease
abscess often located on the back of the neck. Note drop of yellow-
ish pus near the center of the lesion. Carbuncles are caused by Staph-
that is discussed here because several of its features resem-
ylococcus aureus. (Reproduced with permission from Wolff K, Johnson R (eds):
ble toxic shock syndrome caused by the superantigens of
Fitzpatrick’s Color Atlas & Synopsis of Clinical Dermatology. 6th ed. New York: McGraw-
S. aureus (and S. pyogenes). KD is a vasculitis involving
Hill, 2009. Copyright © 2009 by The McGraw-Hill Companies, Inc.)
small and medium-size arteries, especially the coronary
arteries. It is the most common cause of acquired heart
(5) Staphylococcus aureus is the most common cause of
Clinically, KD is characterized by a high fever of at least
postsurgical wound infections which are an important
5 days’ duration; bilateral nonpurulent conjunctivitis;
cause of morbidity and mortality in hospitals. For example, disease in children in the United States.
lesions of the lips and oral mucosa (e.g., strawberry tongue,
mebooksfree.com mebooksfree.com mebooksfree.com feet that often ends with desquamation. mebooksfree.com mebooksfree.com
mebooksfree.com
S. aureus and S. epidermidis are the most common causes of
edema of the lips, and erythema of the oropharynx); cervi-
infections at the site where cardiac pacemakers are installed.
cal lymphadenopathy; a diffuse erythematous, maculo-
(6) Pneumonia can occur in postoperative patients or
papular rash; and erythema and edema of the hands and
following viral respiratory infection, especially influenza.
Staphylococcal pneumonia often leads to empyema or lung
The most characteristic clinical finding of KD is cardiac
abscess. In many hospitals, it is the most common cause of
involvement, especially myocarditis, arrhythmias, and
nosocomial pneumonia in general and especially of ventilator-
regurgitation involving the mitral or aortic valves. The
associated pneumonia in intensive care units. CA-MRSA causes
main cause of morbidity and mortality in KD is aneurysm
a severe necrotizing pneumonia.
of the coronary arteries.
(7) Conjunctivitis typically presents with unilateral
KD is much more common in children of Asian ances-
burning eye pain, hyperemia of the conjunctiva, and a
purulent discharge. The organism is transmitted to the eye
ibility complex (MHC) alleles may predispose to the
by contaminated fingers. Staphylococcus aureus is the most try, leading to speculation that certain major histocompat-
disease. It is a disease of children younger than 5 years of
common cause overall, but S. pneumoniae and Haemophi-
mebooksfree.com
mebooksfree.com mebooksfree.com mebooksfree.com Effective therapy consists of high-dose immune globulins mebooksfree.com
mebooksfree.com
age, often occurring in mini-outbreaks. It occurs world-
lus influenzae are more common in children. Gonococcal
wide but is much more common in Japan.
and nongonococcal (caused by Chlamydia trachomatis)
There is no definitive diagnostic laboratory test for KD.
conjunctivitis is acquired by infants during passage through
the birth canal.
(IVIG) plus high-dose aspirin, which promptly reduce the
(8) Abscesses can occur in any organ when S. aureus
fever and other symptoms and, most importantly, signifi-
circulates in the bloodstream (bacteremia). These abscesses
cantly reduce the occurrence of aneurysms.
mebooksfree.com mebooksfree.com mebooksfree.com mebooksfree.com mebooksfree.com mebooksfree.com