This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Lorian, V. Articles by Markovits, G. Search for Related Content PubMed Articles by Lorian, V. Articles by Markovits, G. Agricola Articles by Lorian, V. Articles by Markovits, G.

 Previous Article  |  Next Article 

Appl Environ Microbiol. 1973 July; 26(1): 116-117
Copyright © 1973 American Society for Microbiology. All Rights Reserved.

Disk Test for the Differentiation of Pneumococci from Other Alpha-Hemolytic Streptococci

¹ Division of Microbiology and Epidemiology, Department of Pathology, The Bronx-Lebanon Hospital Center, Bronx, New York 10456

ABSTRACT

One hundred twenty-five strains of Diplococcus pneumoniae and one hundred twenty-five strains of other alpha-hemolytic streptococci were planted on horse red cell-Brucella agar, and a disk of methicillin was placed on each inoculated plate. All strains were incubated anaerobically at 37 C for 24 h and then exposed to air at 6 C for 48 h. All strains of pneumococci produced a ring of beta-hemolysis surrounding the zone of inhibition produced with the methicillin disk, whereas no strain of alpha-hemolytic streptococci produced beta-hemolysis. It is suggested that this new criterion is useful for the differentiation of pneumococci from other alpha-hemolytic streptococci in those cases where other characteristics were insufficient for an unequivocal identification.