Twinning, MonozygoticGenetic DeterminismCloning, OrganismCloning, MolecularMolecular Sequence DataBase SequencePlasmidsbeta-LactamasesClone CellsAmino Acid SequenceDNA, ComplementarySequence Homology, Amino AcidSequence Analysis, DNADNASequence Homology, Nucleic AcidSequence AlignmentRNA, MessengerEscherichia coliGenes, BacterialPolymerase Chain ReactionChromosome MappingBlotting, SouthernBlotting, NorthernNucleic Acid HybridizationPhylogenyRecombinant ProteinsGene ExpressionGenesRestriction MappingCell LineDNA, BacterialDNA Primers