[PMID]: | 16943188 |
[Au] Autor: | Cremniter J; Mainardi JL; Josseaume N; Quincampoix JC; Dubost L; Hugonnet JE; Marie A; Gutmann L; Rice LB; Arthur M |
[Ad] Endereço: | INSERM U655-LRMA, Centre de Recherches Biomédicales des Cordeliers, Université Paris 6, 15 Rue de l'Ecole de Médecine, Paris 75270, France. |
[Ti] Título: | Novel mechanism of resistance to glycopeptide antibiotics in Enterococcus faecium. |
[So] Source: | J Biol Chem;281(43):32254-62, 2006 Oct 27. |
[Is] ISSN: | 0021-9258 |
[Cp] País de publicação: | United States |
[La] Idioma: | eng |
[Ab] Resumo: | Glycopeptides and beta-lactams are the major antibiotics available for the treatment of infections due to Gram-positive bacteria. Emergence of cross-resistance to these drugs by a single mechanism has been considered as unlikely because they inhibit peptidoglycan polymerization by different mechanisms. The glycopeptides bind to the peptidyl-D-Ala(4)-D-Ala(5) extremity of peptidoglycan precursors and block by steric hindrance the essential glycosyltransferase and D,D-transpeptidase activities of the penicillin-binding proteins (PBPs). The beta-lactams are structural analogues of D-Ala(4)-D-Ala(5) and act as suicide substrates of the D,D-transpeptidase module of the PBPs. Here we have shown that bypass of the PBPs by the recently described beta-lactam-insensitive L,D-transpeptidase from Enterococcus faecium (Ldt(fm)) can lead to high level resistance to glycopeptides and beta-lactams. Cross-resistance was selected by glycopeptides alone or serially by beta-lactams and glycopeptides. In the corresponding mutants, UDP-MurNAc-pentapeptide was extensively converted to UDP-MurNAc-tetrapeptide following hydrolysis of D-Ala(5), thereby providing the substrate of Ldt(fm). Complete elimination of D-Ala(5), a residue essential for glycopeptide binding, was possible because Ldt(fm) uses the energy of the L-Lys(3)-D-Ala(4) peptide bond for cross-link formation in contrast to PBPs, which use the energy of the D-Ala(4)-D-Ala(5) bond. This novel mechanism of glycopeptide resistance was unrelated to the previously identified replacement of D-Ala(5) by D-Ser or D-lactate. |
[Mh] Termos MeSH primário: |
Antibacterianos/farmacologia Farmacorresistência Bacteriana Enterococcus faecium/metabolismo Glicopeptídeos/farmacologia
|
[Mh] Termos MeSH secundário: |
Alanina/metabolismo Substituição de Aminoácidos Reagentes para Ligações Cruzadas/farmacologia Citoplasma/metabolismo Enterococcus faecium/genética Hidrólise Testes de Sensibilidade Microbiana Modelos Biológicos Muramilpentapeptídeo Carboxipeptidase/metabolismo Fragmentos de Peptídeos/química Peptidoglicano/biossíntese Peptidoglicano/química Peptidoglicano/metabolismo Especificidade por Substrato beta-Lactamas/metabolismo
|
[Pt] Tipo de publicação: | JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL; RESEARCH SUPPORT, NON-U.S. GOV'T |
[Nm] Nome de substância:
| 0 (Anti-Bacterial Agents); 0 (Cross-Linking Reagents); 0 (Glycopeptides); 0 (Peptide Fragments); 0 (Peptidoglycan); 0 (beta-Lactams); EC 3.4.17.8 (Muramoylpentapeptide Carboxypeptidase); OF5P57N2ZX (Alanine) |
[Em] Mês de entrada: | 0612 |
[Cu] Atualização por classe: | 161019 |
[Lr] Data última revisão:
| 161019 |
[Sb] Subgrupo de revista: | IM |
[Da] Data de entrada para processamento: | 060901 |
[St] Status: | MEDLINE |
|
|