Rapid extraction method with pronase B for grouping beta-hemolytic streptococci

Area of Science:

• Microbiology
• Immunology
• Clinical Diagnostics

Background:

• Accurate identification of beta-hemolytic streptococci is crucial for patient diagnosis and treatment.
• Traditional serological grouping methods can be time-consuming and may yield variable results.

Purpose of the Study:

• To evaluate the efficacy of Pronase B enzyme for extracting C carbohydrates from beta-hemolytic streptococci.
• To compare the Pronase B method with the standard Lancefield method and the bacitracin disc method for serological grouping.

Main Methods:

• Pronase B enzyme was utilized to extract C carbohydrates from reference strains and clinical isolates of beta-hemolytic streptococci.
• Serological grouping was performed using the Pronase B extraction method.
• Results were compared against the Lancefield grouping method and the bacitracin disc presumptive method.

Main Results:

• The Pronase B method accurately grouped reference strains of streptococci (groups A through N).
• 1,197 clinical isolates of beta-hemolytic streptococci were classified as group A or non-group A with 100% correlation to the Lancefield method.
• The bacitracin disc method exhibited false reactions in 4.1% of group A and 12.7% of non-group A cultures.

Conclusions:

• Pronase B enzyme is a simple, accurate, and reliable method for extracting C carbohydrates for serological grouping of beta-hemolytic streptococci.
• The Pronase B method demonstrates superior accuracy and adaptability for routine clinical laboratory use compared to the bacitracin disc method.