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An antibiogram was constructed (Figures 3, 4 and Mackowiak (1978) cultured sinus tract drainage in
5) and it showed that for the three most common patients with chronic osteomyelitis and found that
organisms, the quinolones are the most effective if the culture was positive for Staphylococcus aureuL
antibiotics. This may be due to the fact that this there was good correlation with culture reports of.
is a new drug and resistant strains have not yet the operative specimens. However, if the culture of
developed. The use of ciprofloxacin has recently the sinus drainage was another organism,there was a
been underscored in a study by Picirillo (1989), poor correlation. Assuming that the same pattern
considering that the drug is effective in a wide range exists in the middle ear cleft since there is a similarity
of both gram positive and gram negative organisms, in the organisms implicated, this might suggest
However, the use of this ciprofloxacin is not recom- that the specimen obtained from the external auditory
mended for chidren nor as a first line drug in the canal may not be the same as those from the middle
management of COM. Gentamicin, which is corn- eardischargewiththosetakenintraoperativelyeg, bone,
monly used otic solution, still has a good sensitivity cholesteatoma and granulation tissue. Computation
(93.7%) for the organisms. The commonly prescribed of the predictive value of transcanal aspirates showed
oral antibiotics ampicillin, trimethoprim, chlo- that there is good to excellent correlation for these
ramphenicol and cephalexin showed a < 80% sensi- organisms using the rating of agreement by Kappa
tivity pattern. This could probably be attributed statistics. This study specifically Shows that when
to the administration of antibiotics intravenously or anyone of the three organisms is cultured, there is
previous oral intake prior to the collection of a positive correlation in 90% of cases. This finding
specimens, may be very imporant in the clinical setting as the
antimicrobial treatment of COM can be fairly accu-
The role of anaerobic organisms in COM has rately guided by doing transcanal aspiration of ear
been the subject of intensive investigation and specu- discharge alone.
lation. The metabolism of facultative species in mixed
infections, by lowering the local concentration of
oxygen and reduction in oxidation-reduction potential, TABLE 5. Correlation of Ear Aspirate with Operative
provides a suitable environment for the anaerobic Specimen Culture.
pathogens. Sugita (1981) elaborates that because
of the obstruction of air around the cholesteatoma Earaspirate No.of Positive Negative Predictive
there is a reduction of the partial pressureof oxygen Patients correlation correlation value
with an inverse increase in cartoon dioxide thus
favoring anaerobic growth. Synergy between the P.mlrabilis 29 29 0 100.0'/,
negative bacilli particularly coliforms and Proteus and
Bacteroidesspecieshave beenreported0ngham, 1977); P.vuloaris 13 11 2 84.6%
In this study, there were four isolates of Bacteroides
sp andin thesetwo B. melaninogenlcus was isolated P.asuroginosa 10 7 3 70.0%
together with Proteus mirabilis. Previous studies
have cited the importance of anaerobic organisms *Predictivevaluee.quahnumberoflmsitiveeorrelatianstimes100
in COM. The apparent low incidence of anaerobic dividedby total numberof patients.
infection in this study maybe due to several factors,
most impor't,3nt of which is the inherent difficulty SUMMARY
in isolating the organism.
A study of 30 patients with COM who underwent
It is a common practice to treat COM empiri- radical mastoidectomy showed that the three most
tally. However when confronted with patients re- common organisms were Proteus mirabilis, Proteus
fractory to the usual medical management, as well vulgaris and Pseudomonas aeruginosa. The isolates
as the significant potential for developing complies- obtained from the transcanal ear aspirate showed good
tions in such cases, culture and sensitivity studies excellent correlation with the operative specimens from
maybe necessary in the proper management of COM. the middle ear (bone, granulation tissue, cholestea-
The question arises whether cultured, specimens toma). The transcanal ear aspirate cult'are maybe
obtained from the external auditory canal would be valuable as a guide in the medicalmanagement of
reflective of those taken directly from the middle ear. COM.
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