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Persistent acute otitis media: I. Causative pathogens
M E Pichichero1, C L Pichichero
1Department of Pediatrics, University of Rochester Medical Center, NY 14642, USA.
Abstract:
In this prospective study tympanocentesis was performed to determine the pathogens isolated from middle ear fluid of 200 ears in 137 children with acute otitis media (AOM) which had not responded after one or two empiric antimicrobial treatment courses (termed persistent AOM). For comparison tympanocentesis from 154 ears in 111 children with AOM not previously treated are described. Patients were enrolled from October, 1989, until September, 1992. In the persistent AOM group amoxicillin and trimethoprim/sulfamethoxazole were the most frequently used antimicrobials before tympanocentesis. Middle ear aspirates produced no pathogenic bacterial growth in 49% of persistent AOM patients, Streptococcus pneumoniae in 24%, Haemophilus influenzae in 7%, Branhamella catarrhalis in 7%, Streptococcus pyogenes in 6%, Staphylococcus aureus in 5% and two pathogens in 3%. Two (18%) of 11 S. pneumoniae isolates tested were penicillin-resistant; 1 was intermediate and 1 was highly resistant. Ten (83%) of 12 H. influenzae and all of 11 B. catarrhalis AOM isolates produced beta-lactamase. In comparison previously untreated AOM patients produced no bacterial growth from tympanocentesis in 30%, S. pneumoniae in 36% (8% penicillin-resistant), H. influenaze in 13% (44% beta-lactamase-producing) and B. catarrhalis in 11% (85% beta-lactamase producing). AOM which is persistent after initial empiric antimicrobial therapy may be caused by middle ear inflammation after bacteria are killed or involve penicillin-resistant S. pneumoniae, beta-lactamase-producing H. influenzae or B. catarrhalis more commonly than occurs in AOM which has not been recently treated.
Insights
Persistent acute otitis media (AOM) in children often shows no bacterial growth or resistant pathogens like penicillin-resistant Streptococcus pneumoniae and beta-lactamase-producing Haemophilus influenzae or Branhamella catarrhalis.
Area of Science:
- Pediatrics
- Infectious Diseases
- Microbiology
Background:
- Acute otitis media (AOM) is a common childhood infection.
- Persistent AOM, defined as AOM unresponsive to initial antimicrobial treatment, requires further investigation.
- Understanding the microbial landscape of persistent AOM is crucial for effective treatment strategies.
Purpose of the Study:
- To identify pathogens in middle ear fluid of children with persistent AOM.
- To compare microbial findings in persistent AOM with previously untreated AOM.
- To assess antimicrobial resistance patterns in isolated pathogens.
Main Methods:
- Prospective study involving tympanocentesis in children with AOM.
- Analysis of middle ear fluid from 200 ears with persistent AOM and 154 ears with untreated AOM.
- Bacterial culture and antimicrobial susceptibility testing.
Main Results:
- No bacterial growth was found in 49% of persistent AOM cases.
- Common pathogens in persistent AOM included Streptococcus pneumoniae (24%), Haemophilus influenzae (7%), and Branhamella catarrhalis (7%).
- Higher rates of penicillin-resistant S. pneumoniae and beta-lactamase-producing H. influenzae and B. catarrhalis were observed in persistent AOM compared to untreated AOM.
Conclusions:
- Persistent AOM may result from non-bacterial inflammation or involve resistant bacterial strains.
- Treatment failure in AOM can be linked to antimicrobial resistance.
- Empiric antimicrobial choices for AOM should consider local resistance patterns.