Genetic similarity between adenoid tissue and middle ear fluid isolates of Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis from Iranian children with otitis media with effusion.
BACKGROUND
Otitis media with effusion (OME) is a common disease among children, in the pathogenesis of which bacterial infections play a critical role. It was suggested that adenoid tissue could serve as a reservoir for bacterial infection, the eustachian tubes being the migration routes of bacteria into the middle ear cavity. The aim of this study was to investigate the genetic similarity between isolates of Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis, obtained from adenoid tissue and middle ear fluid.


METHODS
A total of 60 specimens of middle ear fluids (MEFs) and 45 specimens of adenoid tissue were obtained from 45 children with OME. All the samples were inoculated on culture media for bacterial isolation and identification. The genetic similarity between bacterial isolates was determined by pulsed-field gel electrophoresis (PFGE).


RESULTS
The same bacterial species were simultaneously isolated from adenoid tissue and MEFs of 14 patients, among which, 6 pairs of M. catarrhalis, 5 pairs of S. pneumoniae and 3 pairs of H. influenzae were identified.


CONCLUSIONS
Based on the genetic similarities between isolate pairs, found by PFGE analysis, this study suggested that M. catarrhalis, S. pneumoniae and H. influenzae colonize the adenoid tissue, then migrate to the middle ear cavity and, hence, contribute to the total pathogenesis of OME.
Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
Mohammad
M
Emaneini
Farzaneh
F
Gharibpour
Seyed Sajjad
SS
Khoramrooz
Akbar
A
Mirsalehian
Fereshteh
F
Jabalameli
Davood
D
Darban-Sarokhalil
Mehdi
M
Mirzaii
Asghar
A
Sharifi
Morovat
M
Taherikalani
D000234:Adenoids / Q000382:microbiology; D002648:Child; D002675:Child, Preschool; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D020022:Genetic Predisposition to Disease / Q000453:epidemiology*; D016905:Gram-Negative Bacterial Infections / Q000453:epidemiology / Q000382:microbiology; D016908:Gram-Positive Bacterial Infections / Q000453:epidemiology / Q000382:microbiology; D006193:Haemophilus influenzae / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D015994:Incidence; D007492:Iran / Q000453:epidemiology; D008297:Male; D001936:Moraxella catarrhalis / Q000235:genetics* / Q000302:isolation & purification; D010034:Otitis Media with Effusion / Q000382:microbiology*; D018570:Risk Assessment; D012494:Sampling Studies; D013296:Streptococcus pneumoniae / Q000235:genetics* / Q000302:isolation & purification; D046509:Tissue Culture Techniques
Haemophilus influenzae; Moraxella catarrhalis; Otitis media with effusion; Pulsed-field gel electrophoresis (PFGE); Streptococcus pneumoniae