title: Development of natural and synthetic DNA probes for OXA-2 and TEM-1 beta-lactamases.
abstract: Cloning of a 6.3-kilobase BglII DNA fragment from plasmid R46 permitted the isolation of the OXA-2 beta-lactamase gene. Selected DNA fragments internal and adjacent to the OXA-2 beta-lactamase structural gene were used as probes in homology studies with other plasmid-mediated beta-lactamases. Under conditions of high stringency, no cross hybridization could be detected with DNA probes from within the open reading frame of the OXA-2 structural gene. At a lower stringency, one of two DNA fragments used as probes cross hybridized weakly with the OXA-3 bla gene. Other DNA fragments tested and known to contain sequences flanking the OXA-2 determinant cross hybridized with OXA-3 and PSE-4 plasmid DNA. From the known nucleotide sequence of OXA-2 and TEM-1, we synthesized a series of oligonucleotides corresponding to sequences internal to their respective structural genes. A 12-mer oligonucleotide containing the OXA-2-active-site nucleotide sequences cross hybridized only with OXA-3. All other oligonucleotides tested were found to be specific for their respective OXA-2 or TEM-1 gene. Such beta-lactamase gene probes should facilitate studies of beta-lactamase molecular epidemiology and beta-lactamase gene polymorphism.
mesh_terms: D001483:Base Sequence; D003001:Cloning, Molecular; D004262:DNA Restriction Enzymes; D004269:DNA, Bacterial / Q000032:analysis*; D004587:Electrophoresis, Agar Gel; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D005798:Genes, Bacterial; D009693:Nucleic Acid Hybridization; D010957:Plasmids; D012689:Sequence Homology, Nucleic Acid; D001618:beta-Lactamases / Q000032:analysis / Q000235:genetics*
chemical_list: D004269:DNA, Bacterial; D004262:DNA Restriction Enzymes; D001618:beta-Lactamases