title: Biochemical Characterization of β-Lactamases from Mycobacterium abscessus Complex and Genetic Environment of the β-Lactamase-Encoding Gene.
abstract: The objectives of this study were to determine the kinetic parameters of purified recombinant BlaMaband BlaMmasby spectrophotometry, analyze the genetic environment of the blaMaband blaMmasgenes in both species by polymerase chain reaction and sequencing, furthermore, in silico models of both enzymes in complex with imipenem were obtained by modeling tools. Our results showed that BlaMaband BlaMmashave a similar hydrolysis behavior, displaying high catalytic efficiencies toward penams, cephalothin, and nitrocefin; none of the enzymes are well inhibited by clavulanate. BlaMmashydrolyzes imipenem at higher efficiency than cefotaxime and aztreonam. BlaMaband BlaMmasshowed that their closest structural homologs are KPC-2 and SFC-1, which correlate to the mild carbapenemase activity toward imipenem observed at least for BlaMmas. They also seem to differ from other class A β-lactamases by the presence of a more flexible Ω loop, which could impact in the hydrolysis efficiency against some antibiotics. A -35 consensus sequence (TCGACA) and embedded at the 3' end of MAB_2874, which may constitute the blaMaband blaMmaspromoter. Our results suggest that the resistance mechanisms in fast-growing mycobacteria could be probably evolving toward the production of β-lactamases that have improved catalytic efficiencies against some of the drugs commonly used for the treatment of mycobacterial infections, endangering the use of important drugs like the carbapenems.
authors.affiliation: 1 Universidad de Los Andes , Facultad de Farmacia y Bioanálisis, Laboratorio de Microbiología Molecular, Mérida, Venezuela .
authors.forename: Ana
authors.initials: A
authors.lastname: Ramírez
authors.affiliation: 2 Universidad de Buenos Aires , Facultad de Farmacia y Bioquímica, Laboratorio de Resistencia Bacteriana, Buenos Aires, Argentina .
authors.forename: Melina
authors.initials: M
authors.lastname: Ruggiero
authors.affiliation: 3 Instituto Venezolano de Investigaciones Científicas, Centro de Microbiología y Biología Celular , Caracas, Venezuela .
authors.forename: Carlos
authors.initials: C
authors.lastname: Aranaga
authors.affiliation: 4 Instituto Nacional de Tecnología Agropecuaria, Centro de Investigación en Ciencias Veterinarias y Agronómicas , Instituto de Biotecnología, Castelar, Buenos Aires, Argentina .
authors.forename: Angel
authors.initials: A
authors.lastname: Cataldi
authors.affiliation: 2 Universidad de Buenos Aires , Facultad de Farmacia y Bioquímica, Laboratorio de Resistencia Bacteriana, Buenos Aires, Argentina .
authors.forename: Gabriel
authors.initials: G
authors.lastname: Gutkind
authors.affiliation: 5 Universidad Central de Venezuela , Instituto de Biomedicina, Laboratorio de Tuberculosis, Caracas, Venezuela .
authors.forename: Jacobus H
authors.initials: JH
authors.lastname: de Waard
authors.affiliation: 1 Universidad de Los Andes , Facultad de Farmacia y Bioanálisis, Laboratorio de Microbiología Molecular, Mérida, Venezuela .
authors.forename: María
authors.initials: M
authors.lastname: Araque
authors.affiliation: 2 Universidad de Buenos Aires , Facultad de Farmacia y Bioquímica, Laboratorio de Resistencia Bacteriana, Buenos Aires, Argentina .
authors.forename: Pablo
authors.initials: P
authors.lastname: Power
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002384:Catalysis / Q000187:drug effects; D016384:Consensus Sequence / Q000235:genetics; D024881:Drug Resistance, Bacterial / Q000187:drug effects / Q000235:genetics; D006868:Hydrolysis / Q000187:drug effects; D007700:Kinetics; D008826:Microbial Sensitivity Tests / Q000379:methods; D009161:Mycobacterium / Q000187:drug effects / Q000235:genetics*; D009164:Mycobacterium Infections / Q000188:drug therapy / Q000382:microbiology; D011401:Promoter Regions, Genetic / Q000187:drug effects / Q000235:genetics; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D001618:beta-Lactamases
keywords: Antibiotic resistance; Mycobacterium abscessus; Mycobacterium massiliense; β-lactamase