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Bacteriology of chronic secretory otitis media in children
1Department of Bacteriology, High Institute of Public Health, Alexandria University.
Abstract:
One hundred and four effusions from 66 children with CSOM were cultured for aerobic and anaerobic bacteria. Fifty percent of all effusions yielded bacterial growth and Gram negative organisms constituted 69.2% of those isolates. H. influenza was the most commonly isolated organism (36.5%) followed by B. catarrhalis and Str. pneumoniae. All B. catarrhalis, Staph. aureus and pseudomonas isolates were resistant to ampicillin while cefotaxime was active against all the isolated Gram positive and Gram negative bacteria. Considering B-lactamase production, all the isolated Staph. aureus were BLPs while in case of Gram negative bacteria, not all the ampicillin resistant strains were BLPs.
Insights
Bacterial infections in childhood CSOM effusions are common, with Gram-negative bacteria like H. influenzae predominating. Cefotaxime shows broad activity, while ampicillin resistance is prevalent, particularly in B. catarrhalis and Staph. aureus.
Area of Science:
- Otolaryngology
- Microbiology
- Pediatrics
Background:
- Childhood otitis media, specifically chronic suppurative otitis media (CSOM), remains a significant pediatric health concern.
- Understanding the microbial etiology and antibiotic susceptibility patterns in CSOM effusions is crucial for effective treatment.
Purpose of the Study:
- To identify the bacterial pathogens commonly found in middle ear effusions of children with CSOM.
- To evaluate the in vitro antibiotic susceptibility of these bacterial isolates, focusing on ampicillin and cefotaxime.
- To investigate the role of beta-lactamase production in ampicillin resistance among Gram-negative isolates.
Main Methods:
- Cultures for aerobic and anaerobic bacteria were performed on 104 middle ear effusions from 66 children diagnosed with CSOM.
- Bacterial isolates were identified, and their susceptibility to ampicillin and cefotaxime was determined.
- Beta-lactamase production was assessed in relevant isolates.
Main Results:
- Bacterial growth was observed in 50% of the effusions.
- Gram-negative organisms accounted for 69.2% of all isolates.
- Haemophilus influenzae was the most frequent isolate (36.5%), followed by Moraxella catarrhalis and Streptococcus pneumoniae.
- All isolates of M. catarrhalis, Staphylococcus aureus, and Pseudomonas species were resistant to ampicillin.
- Cefotaxime demonstrated activity against all tested Gram-positive and Gram-negative bacteria.
- All S. aureus isolates were beta-lactamase producers (BLPs), while not all ampicillin-resistant Gram-negative strains were BLPs.
Conclusions:
- Gram-negative bacteria, particularly H. influenzae, are the predominant pathogens in pediatric CSOM effusions.
- Ampicillin exhibits limited efficacy due to widespread resistance, often mediated by beta-lactamase production in S. aureus and some Gram-negative bacteria.
- Cefotaxime represents a viable therapeutic option due to its broad-spectrum activity against common CSOM pathogens.