Occurence of Veillonella and Neisseria in the niches of the human oral cavity.

Samples collected from the dental surface, gingival sulcus, dorsum of the tongue and from the cheek of ten adults (18 to 32 years) were investigated to identify the Veillonella and Neisseria species present by applying the taxonomic criteria suggested in the latest edition of Bergey's Manual. The various niches contain both V. parvula and V. alcalescens, but with the predominance of strains which do not fit precisely the described catalase and putrescine requirements. Eighty-nine out of 100 isolated strains of Gram negative oxidase positive cocci could be identified as N. sicca and N. subflava; about 11 unidentified strains exhibited characteristics of N. flavescens species.