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Capsular Serotyping of Streptococcus pneumoniae Using the Quellung Reaction
Published on: February 24, 2014
[Streptococcal tonsillitis: failure of penicillin therapy]
1Aalborg Sygehus, klinisk mikrobiologisk afdeling.
Abstract:
Group A beta-haemolytic streptococci (GAS) have remained sensitive to penicillin, but penicillin V therapy does not eradicate GAS in 5-30% of cases of GAS tonsillitis. Multiple factors contribute to treatment failure, the foremost among these being lack of compliance with the prescribed therapy, tolerance of GAS towards the killing effect of penicillin, inactivation of penicillin by bacterial beta-lactamases, and absence of bacteriocin-producing non-haemolytic streptococci from the oral flora. The effect of local immunity should be further assessed. It is unlikely that environmental sources of GAS play any significant role. Throat cultures should not routinely be repeated after penicillin treatment. If, in special cases, a new course of treatment is indicated, penicillin V should still be preferred. In the light of modern pharmacological insights, multiple dosing schedules may be desirable in the therapy of GAS tonsillitis.
Insights
Penicillin V therapy fails to eradicate Group A beta-haemolytic streptococci (GAS) in 5-30% of tonsillitis cases. Factors like poor compliance and bacterial resistance contribute to treatment failure, suggesting revised dosing strategies.
Area of Science:
- Microbiology
- Infectious Diseases
- Pharmacology
Context:
- Group A beta-haemolytic streptococci (GAS) are a common cause of tonsillitis.
- Penicillin V is the standard treatment, but eradication rates vary significantly (5-30%).
- Treatment failures necessitate understanding contributing factors to optimize therapeutic outcomes.
Purpose:
- To analyze the multifactorial reasons behind penicillin V treatment failures in GAS tonsillitis.
- To evaluate the role of bacterial tolerance, beta-lactamase activity, and oral flora in treatment outcomes.
- To provide evidence-based recommendations for improving GAS tonsillitis management.
Summary:
- GAS remains sensitive to penicillin, yet penicillin V fails to eradicate the bacteria in 5-30% of tonsillitis cases.
- Key factors contributing to treatment failure include poor patient compliance, GAS tolerance to penicillin, bacterial inactivation of penicillin by beta-lactamases, and absence of beneficial bacteriocin-producing streptococci.
- Environmental sources are unlikely contributors, and routine post-treatment throat cultures are not recommended.
Impact:
- Highlights the need for further assessment of local immunity's role in GAS tonsillitis.
- Suggests penicillin V remains the preferred agent even in cases requiring re-treatment.
- Recommends exploring multiple dosing schedules for penicillin V in GAS tonsillitis based on pharmacological insights to improve eradication rates and patient outcomes.
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