A study of the Va-1 group of pseudomonads and its relationship to Pseudomonas pickettii

The Va-1 group of denitrifying pseudomonads was characterized and compared with Pseudomonas pickettii (Va-2). They share many features but differ in their production of acid from cellobiose, lactose and maltose and in their denitrification (gas from nitrate) at 35 degrees C. DNA-DNA hybridizations between a strain of Va-1 and the type strain of P. pickettii disclosed 84% homology and hence indicated that Va-1 is a biovar of this species. Since both are potential human pathogens, features are presented that distinguish these and other phenotypically similar species that are recovered from clinical specimens.