Characterization of Some Group N Streptococci

Abstract

Group N lactic streptococci were isolated from various sources and characterized by their biochemical, physiological, and sero- logical reactions, as well as their susceptibil- ity to representative bacteriophages. Strep- tococcus cremoris was rarely isolated in the wild state. Streptococcus lactis was recov- ered from water, poultry feed, dairy prod- ucts, frozen vegetables, and meat samples. A comparison of the characteristics of the isolates of S. lactis to strains used as com- mercial dairy starters indicated that they did not differ significantly from the starter isolates except for their phage sensitivity. The biochemical and physiological charac- teristics of the wild-type isolates with their apparent resistance to many bacteriophages encountered as dairy contaminants indi- cate the possible use of these strains of S. lactis as dairy starters.