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Capsular Serotyping of Streptococcus pneumoniae Using the Quellung Reaction
04:25

Capsular Serotyping of Streptococcus pneumoniae Using the Quellung Reaction

Published on: February 24, 2014

[2 strains of pneumococci with reduced penicillin sensitivity in Switzerland]

J Wüst

    Schweizerische Medizinische Wochenschrift
    |April 20, 1985
    PubMed

    Insights

    Emerging penicillin resistance in Streptococcus pneumoniae is a growing concern. Routine susceptibility testing using oxacillin disks is recommended to accurately detect resistance in pneumococci.

    Area of Science:

    • Microbiology
    • Infectious Diseases
    • Antimicrobial Resistance

    Context:

    • Reports indicate increasing resistance of pneumococci to penicillin.
    • Two strains of Streptococcus pneumoniae exhibiting penicillin resistance were recently isolated in Zurich.
    • These strains showed minimal inhibitory concentrations (MICs) of 0.25 and 1.0 mg/L for penicillin G.

    Purpose:

    • To report the emergence of penicillin-resistant Streptococcus pneumoniae strains in Zurich.
    • To highlight the co-resistance patterns observed in these isolates.
    • To recommend appropriate methods for antimicrobial susceptibility testing.

    Summary:

    • Two Streptococcus pneumoniae strains isolated in Zurich displayed significant penicillin resistance.
    • One isolate was also resistant to chloramphenicol and tetracycline.
    • Both strains were resistant to sulfamethoxazole/trimethoprim, underscoring the need for vigilant monitoring.

    Impact:

    • Routine antimicrobial susceptibility testing for clinically significant pneumococci is advised.
    • The study emphasizes the potential for false-susceptible results with penicillin disks in agar diffusion tests.
    • Oxacillin disk testing is recommended for accurate detection of penicillin resistance in Streptococcus pneumoniae.

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