The present invention relates to a method for universal detection of bacteria in biological samples and for specific detection of Escherichia coli, Klebsiella pneumoniae, Enterococcus faecalis, Pseudomonas aeruginosa, Proteus mirabilis, Staphylococcus saprophyticus, Streptococcus pneumoniae, Moraxella catarrhalis and Haemophilus influenzae in urine or any other biological samples, said method comprising denaturation of bacterial DNA to single stranded form and either fixing it on a support or leaving it in solution, contacting said single stranded genetic material with a labeled probe selected from the group consisting of i) fragments of chromosomal DNA of the above-mentioned bacteria and ii) synthetic oligonucleotides whose sequences are derived either from the said fragments of chromosomal DNAs or from sequences available in data banks, all (i and ii) probes being capable to hybridize specifically to …