The invention relates to a method of detecting, by means of molecular identification, a bacterium from one of the Staphylococcus-type species. The inventive method is characterised in that the following are used: a fragment of the rpoB gene of said bacterium, comprising a nucleotide sequence selected from one of the SEQ. ID. No. 11 to 39 sequences, the reverse sequences and the complementary sequences; or an oligonucleotide comprising a sequence having at least 12 consecutive nucleotide patterns included in one of the SEQ. ID. No. 7 to 10 sequences, in which N represents a nucleotide selected from inosine and an equimolar mixture of 4 different nucleotides selected from A, T, C or G and from the oligonucleotides of the reverse sequences and complementary sequences.