title: Glycopeptide resistance vanA operons in Paenibacillus strains isolated from soil.
abstract: The sequence and gene organization of the van operons in vancomycin (MIC of >256 microg/ml)- and teicoplanin (MIC of > or =32 microg/ml)-resistant Paenibacillus thiaminolyticus PT-2B1 and Paenibacillus apiarius PA-B2B isolated from soil were determined. Both operons had regulatory (vanR and vanS), resistance (vanH, vanA, and vanX), and accessory (vanY, vanZ, and vanW) genes homologous to the corresponding genes in enterococcal vanA and vanB operons. The vanA(PT) operon in P. thiaminolyticus PT-2B1 had the same gene organization as that of vanA operons whereas vanA(PA) in P. apiarius PA-B2B resembled vanB operons due to the presence of vanW upstream from the vanHAX cluster but was closer to vanA operons in sequence. Reference P. apiarius strains NRRL B-4299 and NRRL B-4188 were found to harbor operons indistinguishable from vanA(PA) by PCR mapping, restriction fragment length polymorphism, and partial sequencing, suggesting that this operon was species specific. As in enterococci, resistance was inducible by glycopeptides and associated with the synthesis of pentadepsipeptide peptidoglycan precursors ending in D-Ala-D-Lac, as demonstrated by D,D-dipeptidase activities, high-pressure liquid chromatography, and mass spectrometry. The precursors differed from those in enterococci by the presence of diaminopimelic acid instead of lysine in the peptide chain. Altogether, the results are compatible with the notion that van operons in soil Paenibacillus strains and in enterococci have evolved from a common ancestor.
authors.affiliation: Unité des Agents Antibactériens, Institut Pasteur, Paris, France. lg@kvl.dk
authors.forename: Luca
authors.initials: L
authors.lastname: Guardabassi
authors.forename: Bruno
authors.initials: B
authors.lastname: Perichon
authors.forename: Jean
authors.initials: J
authors.lastname: van Heijenoort
authors.forename: Didier
authors.initials: D
authors.lastname: Blanot
authors.forename: Patrice
authors.initials: P
authors.lastname: Courvalin
mesh_terms: D000595:Amino Acid Sequence; D001407:Bacillus / Q000235:genetics* / Q000302:isolation & purification; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D019729:Carbon-Oxygen Ligases / Q000235:genetics*; D024881:Drug Resistance, Bacterial; D005798:Genes, Bacterial; D006020:Glycopeptides / Q000494:pharmacology*; D008969:Molecular Sequence Data; D009876:Operon / Q000235:genetics*; D012988:Soil Microbiology; D017334:Teicoplanin; D014640:Vancomycin / Q000494:pharmacology; D020713:Vancomycin Resistance
chemical_list: D001426:Bacterial Proteins; D006020:Glycopeptides; C071437:VanA ligase, Bacteria; D017334:Teicoplanin; D014640:Vancomycin; D019729:Carbon-Oxygen Ligases