Vol. 15 No. 36
Monday, September 16, 1996
A. Provided by Carmela Groves, R.N., M.S., Chief,
Division of Outbreak Investigation, Maryland Department of Health
and Mental Hygiene
B. The Johns Hopkins Hospital (Information provided
by Dr. Beth Allen, Pathology Resident).
Patient Clinical Information: The patient
is a 31 year old female with no significant past medical history
who presented to the Emergency Department at Johns Hopkins Hospital
with complaints of neck edema, erythema and swelling beginning
three days ago. The symptoms had gotten progressively worse and
she now had complaints of dysphagia. Physical examination was
remarkable for an erythematous, fluctuant, and tender area over
the right anterior neck. Tenderness and fluctuation were revealed
on palpation of the floor of the mouth as well. A CT scan showed
a 4 x 3 x 3 cm phlegmon of the right anterior neck extending from
the angle of the mandible to the lateral pharyngeal space. The
patient was admitted for incision and drainage of the neck abscess
as well as removal of an infected tooth. A large amount of purulent
material was aspirated from the area and sent for culture. Bacterial
cultures grew out the organism Rothia dentocariosa.
Organism: Rothia dentocariosa is the prototypic organsim
of the genus Rothia. The organism was first described
in 1967. The organisms resemble Nocardia and Actinomyces
species but differ from these in their cell wall constituents
and physiology (Pape, 1979). The organism is an aerobic or facultatively
anaerobic, non-endospore forming, non-motile, pleomorphic, Gram
positive coccobacillus that can form filamentous branches. Rod-shaped
forms are produced with growth on agar and more spheroidal forms
are found with growth in broth.
Disease: Rothia dentocariosa is part of the normal
flora of the oral cavity. The pathogenicity of the organism was
first demonstrated experimentally in 1969 using mice. When this
organism causes disease, it is usually associated with dental
caries and periodontal disease. Rothia dentocariosa has
been implicated in a number of other disease states including
a periappendiceal abscess, pilonidal abscess and infectious endocarditis.
One case of infectious endocarditis with a complicating perivalvular
abscess has been reported as well as one case reported with a
complicating brain abscess (Isaacson, 1988). Pneumonia resulting
from R. dentocariosa has been observed in immunocompromised
individuals (Schiff, 1987). In most of the cases of endocarditis
and pneumonia, periodontal disease was identifed in the patients.
Identification: Identification requires growth of the
organism on culture media. Growth is slow in aerobic and microaerophilic
conditions and usually requires 5-7 days of incubation. The colonies
are off-white in color and may be rough or smooth. Gram stain
reveals Gram positive pleomorphic rods with branching and diptheroid
forms. The organism is a mannitol and lactose non-fermenter.
R. dentocariosa is catalase positive which aids in differentiating
it from two other organisms found in the normal flora: Lactobacillus
Treatment: R. dentocariosa is usually sensitive
to several antibiotics including aminoglycosides, tetracycline,
vancomycin, pencillin, erythromycin, ceftriaxone and cefazolin.
Pencillin is the recommended antibiotic of choice for infection.
Barksdale L. Identifying Rothia dentocariosa. Ann Int
Koneman EW(ed), et al. Color Atlas and Textbook of Diagnostic
Microbiology, 4th edition; pp. 498-9.
Pape J, et al. Infective Endocarditis Caused by Rothia dentocariosa.
Ann Int Med, 1979;91:746-8.
Schiff MJ, et al. Rothia dentocariosa Pneumonia in an
Immunocompromised Patient. Lung, 1987; 165:279-82.
Sudduth EJ, et al. Rothia dentocariosa Endocarditis Complicated
by Perivalvular Abscess. Clin ID, 1993;17:772-5.
Isaacson JH, et al. Rothia dentocariosa Endocarditis Complicated
by Brain Abscess. Ann J Med 1988;84:352-4.
Announcements: Joint ID and MMI Seminar Series held at noon on Thursdays - 2030 Hygiene
9/18/96 "Effect of M. tuberculosis on HIV replication" - Delia Goletti, MD, PhD, Laboratory of Immunoregulation, Visiting Associate, NIH-NIAID
9/25/96 "Molecular anatomy of stringent regulation in Escherichia coli" - Dipankar Chatterji, PhD, Ctr Cellular and Molecular Biology, Professor, Hyderabad, India
10/03/96 "Colpain is the target antigen of a Th1 clone that transfers protective immunity against Schistosoma mansoni" - Dragana Jankovic, PhD, Laboratory of Parasitic Diseases, Visiting Scientist, NIH-NIAID
10/10/96 "The impact of HIV viral load on perinatal
transmission and progression of disease in infants" - Thomas
C. Quinn, MD, Professor of Medicine, JHU