A sulfone group-labeled TEM-DNA probe: comparison with a 32P-labeled probe in dot-hybridization.
A non-radioactive DNA probe for the TEM-type beta-lactamase gene was obtained by using the 'Chemiprobe' system. It was used along with a 32P-labeled TEM probe to screen for TEM beta-lactamase gene in 107 bacterial isolates representing 7 Gram-negative genera and previously classified as TEM-positive or negative. The DNA to be tested was extracted from these bacterial isolates by the Birnboim-Doly method and, after blotting into charged nylon membranes, it was submitted to hybridization with either the TEM 'Chemiprobe' or the 32P-TEM probe. The TEM 'Chemiprobe' could detect as few as 25 pg specific DNA if it was used at a concentration of 5 ng per cm2 of membrane. The results obtained by both probes were concordant in 93.5% of the entire sample. The TEM 'Chemiprobe' was specific since only one false positive was observed. Furthermore, it appeared at least as sensitive as the 32P-labeled TEM probe. As the dot-hybridization with the sulfone-labeled probe was sensitive, simple and easy to perform, it will be useful for large-scale screening in clinical laboratory.
Jouvenot
M
M
INSERM U 198, Besançon, France.
Descotes
F
F
Remy-Martin
A
A
Adessi
G L
GL
D015342:DNA Probes; D005796:Genes; D005798:Genes, Bacterial; D006090:Gram-Negative Bacteria / Q000201:enzymology / Q000235:genetics; D009693:Nucleic Acid Hybridization; D010761:Phosphorus Radioisotopes; D010957:Plasmids; D011865:Radioisotope Dilution Technique; D001618:beta-Lactamases / Q000235:genetics*
D015342:DNA Probes; D010761:Phosphorus Radioisotopes; D001618:beta-Lactamases; C034413:beta-lactamase TEM-1