Base Composition, Size and Sequence Similarities of Genome Deoxyribonucleic Acids from Clinical Isolates of Pseudomonas putrefaciens

Abstract

The mean base compositions of DNA from 27 strains of P. putrefaciens, P. rubescens and P. piscicida ranged from 43.4-53.2 mol% GC with genome sizes from 3.04 .times. 109 to 4.23 .times. 109 daltons. On the basis of in vitro DNA-DNA binding, estimated spectrophotometrically from initial renaturation rates, P. putrefaciens strains were heterogeneous in the extent to which they shared similar nucleotide sequences, and were divided into 4 DNA homology groups. The DNA characteristics of strains in these groups correlated with several biochemical characteristics that facilitated identification of clinical isolates of P. putrefaciens. The 2 spp. P. putrefaciens and P. rubescens appear to be synonymous and none of the 4 groups of P. putrefaciens was related in DNA sequences to P. piscicida. P. putrefaciens should therefore be retained as a single species and characteristics for identifying the various groups within the species are listed.