Mg. Rayner et al., EVIDENCE OF BACTERIAL METABOLIC-ACTIVITY IN CULTURE-NEGATIVE OTITIS-MEDIA WITH EFFUSION, JAMA, the journal of the American Medical Association, 279(4), 1998, pp. 296-299
Context.-Otitis media with effusion (OME) can lead to significant hear
ing loss in children. Although previous studies have shown that bacter
ial DNA is present in a significant percentage of effusions sterile by
culture, whether the DNA represents viable organisms or ''fossilized
remains'' is unknown. Objective.-To determine if bacterial messenger R
NA (mRNA), as detected by a reverse transcriptase-polymerase chain rea
ction (RT-PCR)-based assay, is present in chronic pediatric middle ear
effusions that contain bacterial DNA but are sterile by standard cult
ural methods. Bacterial mRNAs have a half-life measured in seconds to
minutes; therefore, detection of bacteria-specific mRNAs would be evid
ence that metabolically active organisms are present. Design.-Blinded
comparative study. Patients.-A total of 93 effusions from pediatric ou
tpatients seen for myringotomy and tube placement for chronic (>3 mont
hs) OME (median age of children, 17 months). Setting.-Tertiary care pe
diatric hospital. Main Outcome Measures.-Percentage of positive test r
esults for RT-PCR-based assays compared with culture for Haemophilus i
nfluenzae and concordance between RT-PCR and PCR-based findings for ba
cterial nucleic acids. Results.-Eleven (11.8%) of the 93 specimens tes
ted positive by culture, PCR, and RT-PCR for H influenzae, A total of
29 specimens (31.2%) were positive by PCR but negative by culture for
H influenzae. All 29 specimens were positive by RT-PCR for H influenza
e-specific mRNA. Conclusions.-The RT-PCR-based assay system can detect
the presence of bacterial mRNA in a significant percentage of cultura
lly sterile middle ear effusions, establishing the presence of viable,
metabolically active, intact organisms in some culture-negative OME.