Isolation and characterization of a DNA probe for Staphylococcus aureus subspecies aureus biovar

The gene encoding for polynucleotide phosphorylase (pnp) of a new biovar of Staphylococcus aureus subsp. aureus (NBSA) has been isolated from a genomic library of strain M280(0). The coding region consisted of a 1094-bp HindIII-HindIII DNA fragment encoding for a protein of 277 amino acids with a calculated molecular mass of 29.5 kDa. The nucleotide sequence of the structural gene, contained a continuous open reading frame of 836 bp, showed significant homology with the genes of bacterial polynucleotide phosphorylase from Bacillus subtilis (67.7% identity), from Haemophilus influenzae (62.4% identity), from Pseudomonas luminescens (61.6% identity), and from Escherichia coli (59.7% identity). DNA-DNA and DNA-colony slot-blot hybridizations demonstrated that the pnp gene, employed as a molecular probe, is specific for the identification of NBSA strains.