USE OF TESTS FOR ACIDIFICATION OF METHYL-ALPHA-D-GLUCOPYRANOSIDE AND SUSCEPTIBILITY TO EFROTOMYCIN FOR DIFFERENTIATION OF STRAINS OF ENTEROCOCCUS AND SOME RELATED GENERA

A total of 107 Enterococcus strains, 10 Vagococcus Fluvialis strains, and 8 Lactococcus garvieae strains were tested for acidification of me thyl-alpha-D-glucopyranoside (MGP) and susceptibility to 100-mu g efro tomycin (EFRO) disks. All 26 strains of Enterococcus casseliflavus, in cluding 3 nonmotile and 2 nonpigmented strains, acidified MGP and were resistant to EFRO, All 22 strains of Enterococcus gallinarum, includi ng 5 nonmotile strains, also acidified MGP and were resistant to EFRO, None of the 26 strains of Enterococcus faecium acidified MGP, and all were susceptible to EFRO. Although all 12 Enterococcus faecalis strai ns were also negative in the MGP test, they were resistant to EFRO, Ot her enterococcal strains gave variable results, All 10 strains of V. f luvialis and all 8 strains of L. garvieae gave positive and negative r esults, respectively, in the MGP test and were, respectively, resistan t and susceptible to EFRO, These results indicate that tests of the pr oduction of acid from MGP and susceptibility to EFRO can be used as ad junct tests in the identification of typical and atypical strains of e nterococci in the clinical microbiology laboratory.