Oligonucleotide probes for the detection of TEM-1 and TEM-2 beta-lactamase genes and their transposons.
We describe the use of molecular probes to detect the TEM-type beta-lactamase genes. As a general probe, we prepared a 656 base pair restriction fragment, entirely within the TEM structural gene. This probe was specific for the TEM family, hybridizing only with TEM-1 and TEM-2. The TEM-1 and TEM-2 beta-lactamases differ by only one amino acid. We synthesized two oligonucleotides whose central bases correspond to this difference. The use of these oligonucleotides enables us to discriminate between TEM-1 and TEM-2 genes. Using oligonucleotides homologous to parts of Tn3, we also monitored the presence of TnA-like transposons in bacteria harboring different beta-lactamase genes. Only the TEM-1 and TEM-2 genes were found to be on transposons with terminal sequences identical to those of Tn3. All hybridization experiments were performed with both dot-blot and colony-hybridization techniques, and the suitability of these two methods for epidemiological studies is compared.
D004251:DNA Transposable Elements; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D004755:Enterobacteriaceae / Q000201:enzymology / Q000235:genetics; D005798:Genes, Bacterial; D009693:Nucleic Acid Hybridization; D009838:Oligodeoxyribonucleotides; D010405:Penicillinase; D011550:Pseudomonas aeruginosa / Q000201:enzymology / Q000235:genetics; D012091:Repetitive Sequences, Nucleic Acid
D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D009838:Oligodeoxyribonucleotides; D010405:Penicillinase