ORAL MICROBIOLOGY
with the Glasgow Outcome Score (referred to
severe disability/vegetative state and death), the
authors also discussed the laboratory findings,
neuroradiological investigation and the treatment
applied.
Of the total number of isolates, 55% were
streptococci, with S. milleri isolates predominating,
followed by anaerobic bacteria (17%) and
staphylococci (15%) isolates. Most of the patients
were treated surgically (burr-hole aspiration in
67% cases and craniotomy in 20% cases), while
antibiotics alone were given in 13% patients, for
a median period of 2 months. The authors found
no solid arguments to consider the administration
of 3rd generation cephalosporin or meropenem
superior to a combination of high-dose penicillin
with metronidazole, which represented the firstline treatment in brain abscess in Denmark for
many years.54
The
Anginosus
streptococci
are
usually
susceptible to beta-lactam antibiotics. However,
there have been found isolates of S. milleri group
from head and neck infections with intermediate
susceptibility to ampicillin and third-generation
of cephalosporins55, and one paper indicated a
proportion of 29% ampicillin-resistant isolates.56
A 2-year study regarding the antimicrobial
susceptibility of more than 1000 isolates of
viridans streptococci from different sites of
infection indicated that all anginosus streptococcal
isolates (166 strains of S. anginosus, 74 strains of
S. constellatus and 50 strains of S. intermedius)
were susceptible to vancomycin, while the
susceptibility rates for: penicillin, ampicillin,
cefotaxime, ceftriaxone, clidamycin, erythromycin,
levofloxacine and tetracycline were of: 93.8%,
94.8%, 97.1%, 96.9%, 86.4%, 84.8%, 97.9%
and 44.2%.57 In the same study, the penicillin
intermediate and resistance rates were found
much higher in case of: S. salivarius (70.2% and
8.8%), S. mitis (39.4% and 20.9%), S. mutans (14.3%
and 28.6%) and S. sanguinis (35.2% and 5%).
However, the proportion of 4.5% (1.8% of the
S. anginosus strains, 8.2% of the S. constellatus
strains and 8% of the S. intermedius strains)
penicillin intermediate and 1.7% (1.2% of the S.
anginosus strains, 0% of the S. constellatus strains
and 6% of the S. intermedius strains) penicillin
resistant isolates of S. anginosus group indicated
the unpredictable susceptibility of these bacteria
to beta-lactam antibiotics and the necessity of
the in vitro susceptibility testing when viridans
streptococcal strains of clinical significance are
isolated from infections requiring antimicrobials.57
The data presented in this paper underline the
role of anginosus streptococci in human pathology
and is meant to raise awareness of the clinicians
about the life-threatening infections, like cerebral
abscess, produced by these bacteria.
Bibliography
1. Facklam R. What happened to the streptococci: overview
of taxonomic and nomenclature changes. Clin Microbiol Rev.
2002;15(4):613-630.
2. Jensen A, Hoshino T, Kilian M. Taxonomy of the Anginosus
group of the genus Streptococcus and description of
Streptococcus anginosus subsp. whileyi subsp. nov.
and Streptococcus constellatus subsp. viborgensis
subsp. nov. Int J Syst Evol Microbiol. 2013;63(Pt 7):2506-25019.
3. Whiley RA, Hall LCM, Hardie JM, Beighton D. A study of
small-colony, beta-haemolytic, Lancefield group C streptococci
within the anginosus group: description of Streptococcus
constellatus subsp. pharyngis subsp. nov., associated
with the human throat and pharyngitis. Int J Syst Bacteriol.
1999;49 Pt 4:1443-1449.
4. Feldman DP, Picerno NA, Porubsky ES. Cavernous sinus
thrombosis complicating odontogenic parapharyngeal space
neck abscess: a case report and discussion. Otolaryngol Head
Neck Surg. 2000;123(6):744–745.
5. Zhang C, Xie B, Shi FD, Hao J. Neurological picture. Multiple
intracranial arteritis and hypothyroidism secondary to
Streptococcus anginosus infection. J Neurol Neurosurg
Psychiatry. 2015;86(9):1044-1045.
158
6. Saito N, Hida A, Koide Y, Ooka T, Ichikawa Y, Shimizu J,
Mukasa A, Nakatomi H, Hatakeyama S, Hayashi T, Tsuji S.
Culture-negative brain abscess with Streptococcus intermedius
infection with diagnosis established by direct nucleotide
sequence analysis of the 16s ribosomal RNA gene. Intern Med.
2012;51(2):211-216.
7. Simone G, Rubini G, Conte A, Goldoni P, Falcone M, Vena A,
Venditti M, Morelli S. Streptococcus anginosus group
disseminated infection: case report and review of literature.
Infez Med. 2012;20(3):145-154.
8. Han JK, Kerschner JE. Streptococcus milleri: an
organism for head and neck infections and abscess. Arch
Otolaryngol Head Neck Surg. 2001;127(6):650-654.
9. Manzar N, Manzar B, Kumar R, Bari ME. The study of etiologic
and demographic characteristics of intracranial brain abscess: a
consecutive case series study from Pakistan. World Neurosurg.
2011;76(1-2):195-200.
10. Chew YK, Cheong JP, Khir A, Brito-Mutunayagam S,
Prepageran N. Complications of chronic suppurative otitis
media: a left otogenic brain abscess and a right mastoid
fistula. Ear Nose Throat J. 2012;91(10):428-430.
11. Bannon PD, McCormack RF. Pott’s puffy tumor and
STOMA.EDUJ (2015) 2 (2)