Mycobacterium abscessus l,d-Transpeptidases Are Susceptible to Inactivation by Carbapenems and Cephalosporins but Not Penicillins.
Antimicrob Agents Chemother
; 61(10)2017 10.
Article
en En
| MEDLINE
| ID: mdl-28760902
ABSTRACT
As a growing number of clinical isolates of Mycobacterium abscessus are resistant to most antibiotics, new treatment options that are effective against these drug-resistant strains are desperately needed. The majority of the linkages in the cell wall peptidoglycan of M. abscessus are synthesized by nonclassical transpeptidases, namely, the l,d-transpeptidases. Emerging evidence suggests that these enzymes represent a new molecular vulnerability in this pathogen. Recent studies have demonstrated that inhibition of these enzymes by the carbapenem class of ß-lactams determines their activity against Mycobacterium tuberculosis Here, we studied the interactions of ß-lactams with two l,d-transpeptidases in M. abscessus, namely, LdtMab1 and LdtMab2, and found that both the carbapenem and cephalosporin, but not penicillin, subclasses of ß-lactams inhibit these enzymes. Contrary to the commonly held belief that combination therapy with ß-lactams is redundant, doripenem and cefdinir exhibit synergy against both pansusceptible M. abscessus and clinical isolates that are resistant to most antibiotics, which suggests that dual-ß-lactam therapy has potential for the treatment of M. abscessus Finally, we solved the first crystal structure of an M. abscessus l,d-transpeptidase, LdtMab2, and using substitutions of critical amino acids in the catalytic site and computational simulations, we describe the key molecular interactions between this enzyme and ß-lactams, which provide an insight into the molecular basis for the relative efficacy of different ß-lactams against M. abscessus.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Penicilinas
/
Peptidoglicano
/
Carbapenémicos
/
Cefalosporinas
/
Peptidil Transferasas
/
Mycobacterium abscessus
/
Antibacterianos
Idioma:
En
Revista:
Antimicrob Agents Chemother
Año:
2017
Tipo del documento:
Article
País de afiliación:
Estados Unidos