Publication Date


Advisor(s) - Committee Chair

Larry Elliott, Scott Ford, Martin Houston

Degree Program

Department of Biology

Degree Type

Master of Science


A total of 198 strains of beta-hemolytic streptococci were Lancefield grouped by the conventional nonserological method and the Phadebact Co-agglutination method. These two methods were then compared to the Lancefield precipitin test. The Phadebact Co-agglutination method and the non - serological method '.ere evaluated as to their sensitivity, accuracy, and suitability as methods for serogrouping betahemolytic streptococci in clinical laboratories. Due to the difference in their grouping ability only Lancefield Groups A and B could be directly compared. There was a 100 percent agreement between both of these methods for the Lancefield grouns A and B, and there were three specimens which were nongroupable by both methods. Identical results for Groups A, B, C, and G were obtained for the Phadebact Co-agglutination method and the Lancefield precipitin test. Only 1.5 percent of the beta-hemolyitc streptococci were nongroupable by Phadebact and the Lancefield precipitin test as compared to 41 percent which were nongroupable by the nonserological method.

A cost-benefit analysis comparison between Phadebact and the nonserological method showed that the Phadebact method was $0.79 less expensive per test than the nonserological method. The Phadebact Co-agglutination method also required only 1 min to group the beta-hemolytic streptococci; however, the nonserological method required an additional 18-24 h.


Biology | Life Sciences

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