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Alonso-García I, Vázquez-Ucha JC, Martínez-Guitián M, Lasarte-Monterrubio C, Rodríguez-Pallares S, Camacho-Zamora P, Rumbo-Feal S, Aja-Macaya P, González-Pinto L, Outeda-García M, Maceiras R, Guijarro-Sánchez P, Muíño-Andrade MJ, Fernández-González A, Oviaño M, González-Bello C, Arca-Suárez J, Beceiro A, Bou G. Interplay between OXA-10 β-Lactamase Production and Low Outer-Membrane Permeability in Carbapenem Resistance in Enterobacterales. Antibiotics (Basel) 2023; 12:999. [PMID: 37370318 DOI: 10.3390/antibiotics12060999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 04/20/2023] [Accepted: 05/30/2023] [Indexed: 06/29/2023] Open
Abstract
The OXA-10 class D β-lactamase has been reported to contribute to carbapenem resistance in non-fermenting Gram-negative bacilli; however, its contribution to carbapenem resistance in Enterobacterales is unknown. In this work, minimum inhibitory concentrations (MICs), whole genome sequencing (WGS), cloning experiments, kinetic assays, molecular modelling studies, and biochemical assays for carbapenemase detection were performed to determine the impact of OXA-10 production on carbapenem resistance in two XDR clinical isolates of Escherichia coli with the carbapenem resistance phenotype (ertapenem resistance). WGS identified the two clinical isolates as belonging to ST57 in close genomic proximity to each other. Additionally, the presence of the blaOXA-10 gene was identified in both isolates, as well as relevant mutations in the genes coding for the OmpC and OmpF porins. Cloning of blaOXA-10 in an E. coli HB4 (OmpC and OmpF-deficient) demonstrated the important contribution of OXA-10 to increased carbapenem MICs when associated with porin deficiency. Kinetic analysis showed that OXA-10 has low carbapenem-hydrolysing activity, but molecular models revealed interactions of this β-lactamase with the carbapenems. OXA-10 was not detected with biochemical tests used in clinical laboratories. In conclusion, the β-lactamase OXA-10 limits the activity of carbapenems in Enterobacterales when combined with low permeability and should be monitored in the future.
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Affiliation(s)
- Isaac Alonso-García
- Servicio de Microbiología and Instituto de Investigación Biomédica A Coruña (INIBIC), Complexo Hospitalario Universitario A Coruña, As Xubias 84, 15006 A Coruña, Spain
| | - Juan Carlos Vázquez-Ucha
- Servicio de Microbiología and Instituto de Investigación Biomédica A Coruña (INIBIC), Complexo Hospitalario Universitario A Coruña, As Xubias 84, 15006 A Coruña, Spain
- CIBER de Enfermedades Infecciosas, Instituto de Salud Carlos III, Madrid, Spain
| | - Marta Martínez-Guitián
- NANOBIOFAR, Centre for Research in Molecular Medicine and Chronic Diseases (CiMUS), Universidad de Santiago de Compostela, Campus Vida Avenida Barcelona s/n, 15782 Santiago de Compostela, Spain
- Servicio de Microbiología and Instituto de Investigación Biomédica A Coruña (INIBIC), Complexo Hospitalario Universitario A Coruña, Universidade da Coruña, As Xubias 84, 15006 A Coruña, Spain
| | - Cristina Lasarte-Monterrubio
- Servicio de Microbiología and Instituto de Investigación Biomédica A Coruña (INIBIC), Complexo Hospitalario Universitario A Coruña, As Xubias 84, 15006 A Coruña, Spain
| | - Salud Rodríguez-Pallares
- Servicio de Microbiología and Instituto de Investigación Biomédica A Coruña (INIBIC), Complexo Hospitalario Universitario A Coruña, As Xubias 84, 15006 A Coruña, Spain
| | - Pablo Camacho-Zamora
- Servicio de Microbiología and Instituto de Investigación Biomédica A Coruña (INIBIC), Complexo Hospitalario Universitario A Coruña, As Xubias 84, 15006 A Coruña, Spain
| | - Soraya Rumbo-Feal
- Servicio de Microbiología and Instituto de Investigación Biomédica A Coruña (INIBIC), Complexo Hospitalario Universitario A Coruña, As Xubias 84, 15006 A Coruña, Spain
| | - Pablo Aja-Macaya
- Servicio de Microbiología and Instituto de Investigación Biomédica A Coruña (INIBIC), Complexo Hospitalario Universitario A Coruña, As Xubias 84, 15006 A Coruña, Spain
| | - Lucía González-Pinto
- Servicio de Microbiología and Instituto de Investigación Biomédica A Coruña (INIBIC), Complexo Hospitalario Universitario A Coruña, As Xubias 84, 15006 A Coruña, Spain
| | - Michelle Outeda-García
- Servicio de Microbiología and Instituto de Investigación Biomédica A Coruña (INIBIC), Complexo Hospitalario Universitario A Coruña, As Xubias 84, 15006 A Coruña, Spain
| | - Romina Maceiras
- Servicio de Microbiología and Instituto de Investigación Biomédica A Coruña (INIBIC), Complexo Hospitalario Universitario A Coruña, As Xubias 84, 15006 A Coruña, Spain
| | - Paula Guijarro-Sánchez
- Servicio de Microbiología and Instituto de Investigación Biomédica A Coruña (INIBIC), Complexo Hospitalario Universitario A Coruña, As Xubias 84, 15006 A Coruña, Spain
| | - María José Muíño-Andrade
- Servicio de Microbiología and Instituto de Investigación Biomédica A Coruña (INIBIC), Complexo Hospitalario Universitario A Coruña, As Xubias 84, 15006 A Coruña, Spain
| | - Ana Fernández-González
- Servicio de Microbiología and Instituto de Investigación Biomédica A Coruña (INIBIC), Complexo Hospitalario Universitario A Coruña, As Xubias 84, 15006 A Coruña, Spain
| | - Marina Oviaño
- Servicio de Microbiología and Instituto de Investigación Biomédica A Coruña (INIBIC), Complexo Hospitalario Universitario A Coruña, As Xubias 84, 15006 A Coruña, Spain
- CIBER de Enfermedades Infecciosas, Instituto de Salud Carlos III, Madrid, Spain
| | - Concepción González-Bello
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS), Departamento de Química Orgánica, Universidade de Santiago de Compostela, Jenaro de la Fuente s/n, 15782 Santiago de Compostela, Spain
| | - Jorge Arca-Suárez
- Servicio de Microbiología and Instituto de Investigación Biomédica A Coruña (INIBIC), Complexo Hospitalario Universitario A Coruña, As Xubias 84, 15006 A Coruña, Spain
- CIBER de Enfermedades Infecciosas, Instituto de Salud Carlos III, Madrid, Spain
| | - Alejandro Beceiro
- Servicio de Microbiología and Instituto de Investigación Biomédica A Coruña (INIBIC), Complexo Hospitalario Universitario A Coruña, As Xubias 84, 15006 A Coruña, Spain
- CIBER de Enfermedades Infecciosas, Instituto de Salud Carlos III, Madrid, Spain
| | - Germán Bou
- Servicio de Microbiología and Instituto de Investigación Biomédica A Coruña (INIBIC), Complexo Hospitalario Universitario A Coruña, As Xubias 84, 15006 A Coruña, Spain
- CIBER de Enfermedades Infecciosas, Instituto de Salud Carlos III, Madrid, Spain
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Structural and Biochemical Features of OXA-517: a Carbapenem and Expanded-Spectrum Cephalosporin Hydrolyzing OXA-48 Variant. Antimicrob Agents Chemother 2023; 67:e0109522. [PMID: 36648230 PMCID: PMC9933634 DOI: 10.1128/aac.01095-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
OXA-48-producing Enterobacterales have now widely disseminated throughout the world. Several variants have now been reported, differing by just a few amino-acid substitutions or deletions, mostly in the region of the loop β5-β6. As OXA-48 hydrolyzes carbapenems but lacks significant expanded-spectrum cephalosporin (ESC) hydrolytic activity, ESCs were suggested as a therapeutic option. Here, we have characterized OXA-517, a natural variant of OXA-48- with an Arg214Lys substitution and a deletion of Ile215 and Glu216 in the β5-β6 loop, capable of hydrolyzing at the same time ESC and carbapenems. MICs values of E. coli expressing blaOXA-517 gene revealed reduced susceptibility to carbapenems (similarly to OXA-48) and resistance to ESCs. Steady-state kinetic parameters revealed high catalytic efficiencies for ESCs and carbapenems. The blaOXA-517 gene was located on a ca. 31-kb plasmid identical to the prototypical IncL blaOXA-48-carrying plasmid except for an IS1R-mediated deletion of 30.7-kb in the tra operon. The crystal structure of OXA-517, determined to 1.86 Å resolution, revealed an expanded active site compared to that of OXA-48, which allows for accommodation of the bulky ceftazidime substrate. Our work illustrates the remarkable propensity of OXA-48-like carbapenemases to evolve through mutation/deletion in the β5-β6 loop to extend its hydrolysis profile to encompass most β-lactam substrates.
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Detection of Acquired Antibiotic Resistance Genes in Domestic Pig (Sus scrofa) and Common Carp (Cyprinus carpio) Intestinal Samples by Metagenomics Analyses in Hungary. Antibiotics (Basel) 2022; 11:antibiotics11101441. [PMID: 36290099 PMCID: PMC9598914 DOI: 10.3390/antibiotics11101441] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 10/16/2022] [Accepted: 10/18/2022] [Indexed: 11/26/2022] Open
Abstract
The aim of this study was metagenomics analyses of acquired antibiotic-resistance genes (ARGs) in the intestinal microbiome of two important food-animal species in Hungary from a One Health perspective. Intestinal content samples were collected from 12 domestic pigs (Sus scrofa) and from a common carp (Cyprinus carpio). Shotgun metagenomic sequencing of DNA purified from the intestinal samples was performed on the Illumina platform. The ResFinder database was applied for detecting acquired ARGs in the assembled metagenomic contigs. Altogether, 59 acquired ARG types were identified, 51 genes from domestic pig and 12 genes from the carp intestinal microbiome. ARG types belonged to the antibiotic classes aminoglycosides (27.1%), tetracyclines (25.4%), β-lactams (16.9%), and others. Of the identified ARGs, tet(E), a blaOXA-48-like β-lactamase gene, as well as cphA4, ampS, aadA2, qnrS2, and sul1, were identified only in carp but not in swine samples. Several of the detected acquired ARGs have not yet been described from food animals in Hungary. The tet(Q), tet(W), tet(O), and mef(A) genes detected in the intestinal microbiome of domestic pigs had also been identified from free-living wild boars in Hungary, suggesting a possible relationship between the occurrence of acquired ARGs in domestic and wild animal populations.
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Pincus NB, Rosas-Lemus M, Gatesy SWM, Bertucci HK, Brunzelle JS, Minasov G, Shuvalova LA, Lebrun-Corbin M, Satchell KJF, Ozer EA, Hauser AR, Bachta KER. Functional and Structural Characterization of OXA-935, a Novel OXA-10-Family β-Lactamase from Pseudomonas aeruginosa. Antimicrob Agents Chemother 2022; 66:e0098522. [PMID: 36129295 PMCID: PMC9578422 DOI: 10.1128/aac.00985-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 08/29/2022] [Indexed: 11/20/2022] Open
Abstract
Resistance to antipseudomonal penicillins and cephalosporins is often driven by the overproduction of the intrinsic β-lactamase AmpC. However, OXA-10-family β-lactamases are a rich source of resistance in Pseudomonas aeruginosa. OXA β-lactamases have a propensity for mutation that leads to extended spectrum cephalosporinase and carbapenemase activity. In this study, we identified isolates from a subclade of the multidrug-resistant (MDR) high risk P. aeruginosa clonal complex CC446 with a resistance to ceftazidime. A genomic analysis revealed that these isolates harbored a plasmid containing a novel allele of blaOXA-10, named blaOXA-935, which was predicted to produce an OXA-10 variant with two amino acid substitutions: an aspartic acid instead of a glycine at position 157 and a serine instead of a phenylalanine at position 153. The G157D mutation, present in OXA-14, is associated with the resistance of P. aeruginosa to ceftazidime. Compared to OXA-14, OXA-935 showed increased catalytic efficiency for ceftazidime. The deletion of blaOXA-935 restored the sensitivity to ceftazidime, and susceptibility profiling of P. aeruginosa laboratory strains expressing blaOXA-935 revealed that OXA-935 conferred ceftazidime resistance. To better understand the impacts of the variant amino acids, we determined the crystal structures of OXA-14 and OXA-935. Compared to OXA-14, the F153S mutation in OXA-935 conferred increased flexibility in the omega (Ω) loop. Amino acid changes that confer extended spectrum cephalosporinase activity to OXA-10-family β-lactamases are concerning, given the rising reliance on novel β-lactam/β-lactamase inhibitor combinations, such as ceftolozane-tazobactam and ceftazidime-avibactam, to treat MDR P. aeruginosa infections.
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Affiliation(s)
- Nathan B. Pincus
- Department of Microbiology-Immunology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA
| | - Monica Rosas-Lemus
- Department of Microbiology-Immunology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA
- Center for Structural Genomics of Infectious Diseases, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA
| | - Samuel W. M. Gatesy
- Department of Medicine, Division of Infectious Diseases, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA
| | - Hanna K. Bertucci
- Department of Medicine, Division of Infectious Diseases, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA
| | - Joseph S. Brunzelle
- Northwestern Synchrotron Research Center, Life Sciences Collaborative Access Team, Northwestern University, Argonne, Illinois, USA
| | - George Minasov
- Department of Microbiology-Immunology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA
- Center for Structural Genomics of Infectious Diseases, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA
| | - Ludmilla A. Shuvalova
- Department of Microbiology-Immunology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA
- Center for Structural Genomics of Infectious Diseases, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA
| | - Marine Lebrun-Corbin
- Department of Microbiology-Immunology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA
| | - Karla J. F. Satchell
- Department of Microbiology-Immunology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA
- Center for Structural Genomics of Infectious Diseases, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA
| | - Egon A. Ozer
- Department of Medicine, Division of Infectious Diseases, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA
- Center for Pathogen Genomics and Microbial Evolution, Institute for Global Health, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA
| | - Alan R. Hauser
- Department of Microbiology-Immunology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA
- Department of Medicine, Division of Infectious Diseases, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA
| | - Kelly E. R. Bachta
- Department of Microbiology-Immunology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA
- Department of Medicine, Division of Infectious Diseases, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA
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5
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Avci FG, Tastekil I, Jaisi A, Ozbek Sarica P, Sariyar Akbulut B. A review on the mechanistic details of OXA enzymes of ESKAPE pathogens. Pathog Glob Health 2022; 117:219-234. [PMID: 35758005 PMCID: PMC10081068 DOI: 10.1080/20477724.2022.2088496] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022] Open
Abstract
The production of β-lactamases is a prevalent mechanism that poses serious pressure on the control of bacterial resistance. Furthermore, the unavoidable and alarming increase in the transmission of bacteria producing extended-spectrum β-lactamases complicates treatment alternatives with existing drugs and/or approaches. Class D β-lactamases, designated as OXA enzymes, are characterized by their activity specifically towards oxacillins. They are widely distributed among the ESKAPE bugs that are associated with antibiotic resistance and life-threatening hospital infections. The inadequacy of current β-lactamase inhibitors for conventional treatments of 'OXA' mediated infections confirms the necessity of new approaches. Here, the focus is on the mechanistic details of OXA-10, OXA-23, and OXA-48, commonly found in highly virulent and antibiotic-resistant pathogens Acinetobacter baumannii, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Enterobacter spp. to describe their similarities and differences. Furthermore, this review contains a specific emphasis on structural and computational perspectives, which will be valuable to guide efforts in the design/discovery of a common single-molecule drug against ESKAPE pathogens.
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Affiliation(s)
- Fatma Gizem Avci
- Bioengineering Department, Uskudar University, Uskudar, 34662, Turkey
| | - Ilgaz Tastekil
- Bioengineering Department, Marmara University, Kadikoy, 34722, Turkey
| | - Amit Jaisi
- Drug and Cosmetics Excellence Center, School of Pharmacy, Walailak University, 80160, Nakhon Si Thammarat, Thailand
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Mitchell JM, June CM, Baggett VL, Lowe BC, Ruble JF, Bonomo RA, Leonard DA, Powers RA. Conformational flexibility in carbapenem hydrolysis drives substrate specificity of the class D carbapenemase OXA-24/40. J Biol Chem 2022; 298:102127. [PMID: 35709986 PMCID: PMC9293634 DOI: 10.1016/j.jbc.2022.102127] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 06/07/2022] [Accepted: 06/09/2022] [Indexed: 12/03/2022] Open
Abstract
The evolution of multidrug resistance in Acinetobacter spp. increases the risk of our best antibiotics losing their efficacy. From a clinical perspective, the carbapenem-hydrolyzing class D β-lactamase subfamily present in Acinetobacter spp. is particularly concerning because of its ability to confer resistance to carbapenems. The kinetic profiles of class D β-lactamases exhibit variability in carbapenem hydrolysis, suggesting functional differences. To better understand the structure–function relationship between the carbapenem-hydrolyzing class D β-lactamase OXA-24/40 found in Acinetobacter baumannii and carbapenem substrates, we analyzed steady-state kinetics with the carbapenem antibiotics meropenem and ertapenem and determined the structures of complexes of OXA-24/40 bound to imipenem, meropenem, doripenem, and ertapenem, as well as the expanded-spectrum cephalosporin cefotaxime, using X-ray crystallography. We show that OXA-24/40 exhibits a preference for ertapenem compared with meropenem, imipenem, and doripenem, with an increase in catalytic efficiency of up to fourfold. We suggest that superposition of the nine OXA-24/40 complexes will better inform future inhibitor design efforts by providing insight into the complicated and varying ways in which carbapenems are selected and bound by class D β-lactamases.
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Affiliation(s)
- Joshua M Mitchell
- Department of Chemistry, Grand Valley State University, Allendale, MI
| | - Cynthia M June
- Department of Chemistry, Grand Valley State University, Allendale, MI
| | - Vincent L Baggett
- Department of Chemistry, Grand Valley State University, Allendale, MI
| | - Beth C Lowe
- Department of Chemistry, Grand Valley State University, Allendale, MI
| | - James F Ruble
- Department of Chemistry, Grand Valley State University, Allendale, MI
| | - Robert A Bonomo
- Research Service, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, 10701 East Boulevard, Cleveland, OH; Departments of Medicine, Biochemistry, Molecular Biology and Microbiology, Pharmacology, and Proteomics and Bioinformatics, Case Western Reserve University School of Medicine, Cleveland, OH; CWRU-Cleveland VAMC Center for Antimicrobial Resistance and Epidemiology (Case VA CARES) Cleveland, OH.
| | - David A Leonard
- Department of Chemistry, Grand Valley State University, Allendale, MI
| | - Rachel A Powers
- Department of Chemistry, Grand Valley State University, Allendale, MI.
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Hirvonen VA, Weizmann TM, Mulholland AJ, Spencer J, van der Kamp MW. Multiscale Simulations Identify Origins of Differential Carbapenem Hydrolysis by the OXA-48 β-Lactamase. ACS Catal 2022; 12:4534-4544. [PMID: 35571461 PMCID: PMC9097296 DOI: 10.1021/acscatal.1c05694] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 03/22/2022] [Indexed: 12/27/2022]
Abstract
OXA-48 β-lactamases are frequently encountered in bacterial infections caused by carbapenem-resistant Gram-negative bacteria. Due to the importance of carbapenems in the treatment of healthcare-associated infections and the increasingly wide dissemination of OXA-48-like enzymes on plasmids, these β-lactamases are of high clinical significance. Notably, OXA-48 hydrolyzes imipenem more efficiently than other commonly used carbapenems, such as meropenem. Here, we use extensive multiscale simulations of imipenem and meropenem hydrolysis by OXA-48 to dissect the dynamics and to explore differences in the reactivity of the possible conformational substates of the respective acylenzymes. Quantum mechanics/molecular mechanics (QM/MM) simulations of the deacylation reaction for both substrates demonstrate that deacylation is favored when the 6α-hydroxyethyl group is able to hydrogen bond to the water molecule responsible for deacylation but disfavored by the increasing hydration of either oxygen of the carboxylated Lys73 general base. Differences in free energy barriers calculated from the QM/MM simulations correlate well with the experimentally observed differences in hydrolytic efficiency between meropenem and imipenem. We conclude that the impaired breakdown of meropenem, compared to imipenem, which arises from a subtle change in the hydrogen bonding pattern between the deacylating water molecule and the antibiotic, is most likely induced by the meropenem 1β-methyl group. In addition to increased insights into carbapenem breakdown by OXA β-lactamases, which may aid in future efforts to design antibiotics or inhibitors, our approach exemplifies the combined use of atomistic simulations in determining the possible different enzyme-substrate substates and their influence on enzyme reaction kinetics.
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Affiliation(s)
- Viivi
H. A. Hirvonen
- School
of Biochemistry, University of Bristol, University Walk, Bristol BS8 1TD, U.K.
- Centre
for Computational Chemistry, School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K.
| | - Tal Moshe Weizmann
- School
of Biochemistry, University of Bristol, University Walk, Bristol BS8 1TD, U.K.
| | - Adrian J. Mulholland
- Centre
for Computational Chemistry, School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K.
| | - James Spencer
- School
of Cellular and Molecular Medicine, University
of Bristol, University
Walk, Bristol BS8 1TD, U.K.
| | - Marc W. van der Kamp
- School
of Biochemistry, University of Bristol, University Walk, Bristol BS8 1TD, U.K.
- Centre
for Computational Chemistry, School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K.
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Sun Y, Han R, Ding L, Yang Y, Guo Y, Wu S, Hu F, Yin D. First Report of bla OXA-677 with Enhanced Meropenem-Hydrolyzing Ability in Pseudomonas aeruginosa in China. Infect Drug Resist 2022; 14:5725-5733. [PMID: 35002263 PMCID: PMC8725689 DOI: 10.2147/idr.s340662] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 12/09/2021] [Indexed: 12/18/2022] Open
Abstract
Purpose OXA-10-type class D β-lactamases have shown their evolutionary potential of enhancing carbapenem resistance. This study aimed to elucidate the role of OXA-10 variants in clinical isolated multidrug resistant (MDR) Pseudomonas aeruginosa and characterize the first appearance of OXA-677 in China. Methods Six blaOXA-10-like-positive strains were screened by PCR from 41 P. aeruginosa strains, which were resistant to both carbapenems and ceftazidime-avibactam, collected across China in 2018. The minimum inhibitory concentrations (MIC) were determined with the broth microdilution method. The resistance-associated genes and genetic environment were investigated by whole-genome sequencing (WGS). The function and mechanism of OXA-677 β-lactamase were identified by molecular cloning and protein structure modeling. Results All the blaOXA-10-like-positive Pseudomonas aeruginosa were MDR strains. They also had outer membrane porin defects and produced β-lactam resistance gene blaPER-1, fluoroquinolone-resistant gene crpP, aminoglycoside-resistance gene aph(3ʹ)-IIb, aph(6)-Id, aacA and aadA, fosfomycin-resistance gene fosA, sulfamethoxazole-resistance gene sul1, and chloramphenicol-resistance gene catB7. All blaOXA-10 variants were located in a Tn1403-related transposon, containing aacA4-12-blaOXA-677-aadA1, aacA4-12-blaOXA-101-aadA5, and blaOXA-246-aacA3-aadA13 gene cassette arrays, respectively. Notably, the blaOXA-677 producer showed a high MIC level of meropenem (MIC>64 mg/L). Compared to blaOXA-10, blaOXA-677 was found a G-to-T transversion at position 350, leading to a phenylalanine-for-valine substitution in position 117, which is closer to leucine155 in the omega loop of the active site. MIC of meropenem for E. coli DH5α with the recombinant plasmid pHSG398 carrying blaOXA-677 was elevated by 8 times. Conclusion We speculate that the OXA-10-like enzymes and the decrease of membrane permeability confer carbapenem resistance, and the V117 substitution in OXA-677 might lead to a higher resistance level of meropenem.
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Affiliation(s)
- Yue Sun
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, People's Republic of China.,Key Laboratory of Clinical Pharmacology of Antibiotics, Ministry of Health, Shanghai, People's Republic of China
| | - Renru Han
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, People's Republic of China.,Key Laboratory of Clinical Pharmacology of Antibiotics, Ministry of Health, Shanghai, People's Republic of China
| | - Li Ding
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, People's Republic of China.,Key Laboratory of Clinical Pharmacology of Antibiotics, Ministry of Health, Shanghai, People's Republic of China
| | - Yang Yang
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, People's Republic of China.,Key Laboratory of Clinical Pharmacology of Antibiotics, Ministry of Health, Shanghai, People's Republic of China
| | - Yan Guo
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, People's Republic of China.,Key Laboratory of Clinical Pharmacology of Antibiotics, Ministry of Health, Shanghai, People's Republic of China
| | - Shi Wu
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, People's Republic of China.,Key Laboratory of Clinical Pharmacology of Antibiotics, Ministry of Health, Shanghai, People's Republic of China
| | - Fupin Hu
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, People's Republic of China.,Key Laboratory of Clinical Pharmacology of Antibiotics, Ministry of Health, Shanghai, People's Republic of China
| | - Dandan Yin
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, People's Republic of China.,Key Laboratory of Clinical Pharmacology of Antibiotics, Ministry of Health, Shanghai, People's Republic of China
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9
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Loch JI, Imiolczyk B, Sliwiak J, Wantuch A, Bejger M, Gilski M, Jaskolski M. Crystal structures of the elusive Rhizobium etli L-asparaginase reveal a peculiar active site. Nat Commun 2021; 12:6717. [PMID: 34795296 PMCID: PMC8602277 DOI: 10.1038/s41467-021-27105-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 11/01/2021] [Indexed: 12/04/2022] Open
Abstract
Rhizobium etli, a nitrogen-fixing bacterial symbiont of legume plants, encodes an essential L-asparaginase (ReAV) with no sequence homology to known enzymes with this activity. High-resolution crystal structures of ReAV show indeed a structurally distinct, dimeric enzyme, with some resemblance to glutaminases and β-lactamases. However, ReAV has no glutaminase or lactamase activity, and at pH 9 its allosteric asparaginase activity is relatively high, with Km for L-Asn at 4.2 mM and kcat of 438 s-1. The active site of ReAV, deduced from structural comparisons and confirmed by mutagenesis experiments, contains a highly specific Zn2+ binding site without a catalytic role. The extensive active site includes residues with unusual chemical properties. There are two Ser-Lys tandems, all connected through a network of H-bonds to the Zn center, and three tightly bound water molecules near Ser48, which clearly indicate the catalytic nucleophile.
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Affiliation(s)
- Joanna I Loch
- Department of Crystal Chemistry and Crystal Physics, Faculty of Chemistry, Jagiellonian University, Krakow, Poland
| | - Barbara Imiolczyk
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland
| | - Joanna Sliwiak
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland
| | - Anna Wantuch
- Department of Crystal Chemistry and Crystal Physics, Faculty of Chemistry, Jagiellonian University, Krakow, Poland
| | - Magdalena Bejger
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland
| | - Miroslaw Gilski
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland
- Department of Crystallography, Faculty of Chemistry, A. Mickiewicz University, Poznan, Poland
| | - Mariusz Jaskolski
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland.
- Department of Crystallography, Faculty of Chemistry, A. Mickiewicz University, Poznan, Poland.
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10
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Chiou J, Cheng Q, Shum PTF, Wong MHY, Chan EWC, Chen S. Structural and Functional Characterization of OXA-48: Insight into Mechanism and Structural Basis of Substrate Recognition and Specificity. Int J Mol Sci 2021; 22:ijms222111480. [PMID: 34768916 PMCID: PMC8583920 DOI: 10.3390/ijms222111480] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Revised: 10/10/2021] [Accepted: 10/21/2021] [Indexed: 02/04/2023] Open
Abstract
Class D β-lactamase OXA-48 is widely distributed among Gram-negative bacteria and is an important determinant of resistance to the last-resort carbapenems. Nevertheless, the detailed mechanism by which this β-lactamase hydrolyzes its substrates remains poorly understood. In this study, the complex structures of OXA-48 and various β-lactams were modeled and the potential active site residues that may interact with various β-lactams were identified and characterized to elucidate their roles in OXA-48 substrate recognition. Four residues, namely S70, K73, S118, and K208 were found to be essential for OXA-48 to undergo catalytic hydrolysis of various penicillins and carbapenems both in vivo and in vitro. T209 was found to be important for hydrolysis of imipenem, whereas R250 played a major role in hydrolyzing ampicillin, imipenem, and meropenem most likely by forming a H-bond or salt-bridge between the side chain of these two residues and the carboxylate oxygen ions of the substrates. Analysis of the effect of substitution of alanine in two residues, W105 and L158, revealed their roles in mediating the activity of OXA-48. Our data show that these residues most likely undergo hydrophobic interaction with the R groups and the core structure of the β-lactam ring in penicillins and the carbapenems, respectively. Unlike OXA-58, mass spectrometry suggested a loss of the C6-hydroxyethyl group during hydrolysis of meropenem by OXA-48, which has never been demonstrated in Class D carbapenemases. Findings in this study provide comprehensive knowledge of the mechanism of the substrate recognition and catalysis of OXA-type β-lactamases.
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Affiliation(s)
- Jiachi Chiou
- State Key Laboratory of Chiroscience, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China; (J.C.); (Q.C.); (P.T.-f.S.); (M.H.-y.W.); (E.W.-c.C.)
| | - Qipeng Cheng
- State Key Laboratory of Chiroscience, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China; (J.C.); (Q.C.); (P.T.-f.S.); (M.H.-y.W.); (E.W.-c.C.)
- Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, Hong Kong, China
| | - Perry Tim-fat Shum
- State Key Laboratory of Chiroscience, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China; (J.C.); (Q.C.); (P.T.-f.S.); (M.H.-y.W.); (E.W.-c.C.)
| | - Marcus Ho-yin Wong
- State Key Laboratory of Chiroscience, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China; (J.C.); (Q.C.); (P.T.-f.S.); (M.H.-y.W.); (E.W.-c.C.)
| | - Edward Wai-chi Chan
- State Key Laboratory of Chiroscience, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China; (J.C.); (Q.C.); (P.T.-f.S.); (M.H.-y.W.); (E.W.-c.C.)
| | - Sheng Chen
- Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, Hong Kong, China
- Correspondence:
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11
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Mora-Ochomogo M, Lohans CT. β-Lactam antibiotic targets and resistance mechanisms: from covalent inhibitors to substrates. RSC Med Chem 2021; 12:1623-1639. [PMID: 34778765 PMCID: PMC8528271 DOI: 10.1039/d1md00200g] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 07/25/2021] [Indexed: 12/24/2022] Open
Abstract
The β-lactams are the most widely used antibacterial agents worldwide. These antibiotics, a group that includes the penicillins and cephalosporins, are covalent inhibitors that target bacterial penicillin-binding proteins and disrupt peptidoglycan synthesis. Bacteria can achieve resistance to β-lactams in several ways, including the production of serine β-lactamase enzymes. While β-lactams also covalently interact with serine β-lactamases, these enzymes are capable of deacylating this complex, treating the antibiotic as a substrate. In this tutorial-style review, we provide an overview of the β-lactam antibiotics, focusing on their covalent interactions with their target proteins and resistance mechanisms. We begin by describing the structurally diverse range of β-lactam antibiotics and β-lactamase inhibitors that are currently used as therapeutics. Then, we introduce the penicillin-binding proteins, describing their functions and structures, and highlighting their interactions with β-lactam antibiotics. We next describe the classes of serine β-lactamases, exploring some of the mechanisms by which they achieve the ability to degrade β-lactams. Finally, we introduce the l,d-transpeptidases, a group of bacterial enzymes involved in peptidoglycan synthesis which are also targeted by β-lactam antibiotics. Although resistance mechanisms are now prevalent for all antibiotics in this class, past successes in antibiotic development have at least delayed this onset of resistance. The β-lactams continue to be an essential tool for the treatment of infectious disease, and recent advances (e.g., β-lactamase inhibitor development) will continue to support their future use.
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Affiliation(s)
| | - Christopher T Lohans
- Department of Biomedical and Molecular Sciences, Queen's University Kingston ON K7L 3N6 Canada
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12
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Antimicrobial Resistance Conferred by OXA-48 β-Lactamases: Towards a Detailed Mechanistic Understanding. Antimicrob Agents Chemother 2021; 65:AAC.00184-21. [PMID: 33753332 DOI: 10.1128/aac.00184-21] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
OXA-48-type β-lactamases are now routinely encountered in bacterial infections caused by carbapenem-resistant Enterobacterales These enzymes are of high and growing clinical significance due to the importance of carbapenems in treatment of health care-associated infections by Gram-negative bacteria, the wide and increasing dissemination of OXA-48 enzymes on plasmids, and the challenges posed by their detection. OXA-48 confers resistance to penicillin (which is efficiently hydrolyzed) and carbapenem antibiotics (which is more slowly broken down). In addition to the parent enzyme, a growing array of variants of OXA-48 is now emerging. The spectrum of activity of these variants varies, with some hydrolyzing expanded-spectrum oxyimino-cephalosporins. The growth in importance and diversity of the OXA-48 group has motivated increasing numbers of studies that aim to elucidate the relationship between structure and specificity and establish the mechanistic basis for β-lactam turnover in this enzyme family. In this review, we collate recently published structural, kinetic, and mechanistic information on the interactions between clinically relevant β-lactam antibiotics and inhibitors and OXA-48 β-lactamases. Collectively, these studies are starting to form a detailed picture of the underlying bases for the differences in β-lactam specificity between OXA-48 variants and the consequent differences in resistance phenotype. We focus specifically on aspects of carbapenemase and cephalosporinase activities of OXA-48 β-lactamases and discuss β-lactamase inhibitor development in this context. Throughout the review, we also outline key open research questions for future investigation.
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13
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Abstract
Very low antibiotic concentrations have been shown to drive the evolution of antimicrobial resistance. While substantial progress has been made to understand the driving role of low concentrations during resistance development for different antimicrobial classes, the importance of β-lactams, the most commonly used antibiotics, is still poorly studied. Our current understanding of how low antibiotic concentrations shape the evolution of contemporary β-lactamases is limited. Using the widespread carbapenemase OXA-48, we tested the long-standing hypothesis that selective compartments with low antibiotic concentrations cause standing genetic diversity that could act as a gateway to developing clinical resistance. Here, we subjected Escherichia coli expressing blaOXA-48, on a clinical plasmid, to experimental evolution at sub-MICs of ceftazidime. We identified and characterized seven single variants of OXA-48. Susceptibility profiles and dose-response curves showed that they increased resistance only marginally. However, in competition experiments at sub-MICs of ceftazidime, they demonstrated strong selectable fitness benefits. Increased resistance was also reflected in elevated catalytic efficiencies toward ceftazidime. These changes are likely caused by enhanced flexibility of the Ω- and β5-β6 loops and fine-tuning of preexisting active site residues. In conclusion, low-level concentrations of β-lactams can drive the evolution of β-lactamases through cryptic phenotypes which may act as stepping-stones toward clinical resistance. IMPORTANCE Very low antibiotic concentrations have been shown to drive the evolution of antimicrobial resistance. While substantial progress has been made to understand the driving role of low concentrations during resistance development for different antimicrobial classes, the importance of β-lactams, the most commonly used antibiotics, is still poorly studied. Here, we shed light on the evolutionary impact of low β-lactam concentrations on the widespread β-lactamase OXA-48. Our data indicate that the exposure to β-lactams at very low concentrations enhances β-lactamase diversity and drives the evolution of β-lactamases by significantly influencing their substrate specificity. Thus, in contrast to high concentrations, low levels of these drugs may substantially contribute to the diversification and divergent evolution of these enzymes, providing a standing genetic diversity that can be selected and mobilized when antibiotic pressure increases.
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14
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Wang L, Gu J, Feng Y, Wang M, Tong Y, Liu Y, Lyu X, Yang R. Enhancement of the Isomerization Activity and Thermostability of Cellobiose 2-Epimerase from Caldicellulosiruptor saccharolyticus by Exchange of a Flexible Loop. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:1907-1915. [PMID: 33541071 DOI: 10.1021/acs.jafc.0c07073] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Cellobiose 2-epimerase (CE) offers a promising enzymatic approach to produce lactulose. However, its application is limited by the unsatisfactory isomerization activity and thermostability. Our study attempted to optimize the catalytic performances of CEs by flexible loop exchange, for which four mutants were constructed using CsCE (CE from Caldicellulosiruptor saccharolyticus) as a template. As a result, all mutants maintained the same catalytic directions as the templates. Mutant RmC displayed a 2.2- and 1.34-fold increase in the isomerization activity and catalytic efficiency, respectively. According to the results of molecular dynamics (MD) simulations, it was revealed that the loop exchange in RmC enlarged the entrance of the active site for substrate binding and benefited proton transfer involved in the isomerization process. Besides, the t1/2 of mutant StC at 70 °C was increased from 29.07 to 38.29 h, owing to the abundance of rigid residues (proline) within the flexible loop of StC. Our work demonstrated that the isomerization activity and thermostability of CEs were closely related to the flexible loop surrounding the active site, which provides a new perspective to engineer CEs for higher lactulose production.
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Affiliation(s)
- Lu Wang
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Jiali Gu
- College of Life Sciences, Huzhou University, Huzhou 313000, China
| | - Yinghui Feng
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Mingming Wang
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Yanjun Tong
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Yingjie Liu
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Xiaomei Lyu
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Ruijin Yang
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
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15
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Stojanoski V, Hu L, Sankaran B, Wang F, Tao P, Prasad BVV, Palzkill T. Mechanistic Basis of OXA-48-like β-Lactamases' Hydrolysis of Carbapenems. ACS Infect Dis 2021; 7:445-460. [PMID: 33492952 DOI: 10.1021/acsinfecdis.0c00798] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Carbapenem-hydrolyzing class D β-lactamases (CHDLs) are an important source of resistance to these last resort β-lactam antibiotics. OXA-48 is a member of a group of CHDLs named OXA-48-like enzymes. On the basis of sequence similarity, OXA-163 can be classified as an OXA-48-like enzyme, but it has altered substrate specificity. Compared to OXA-48, it shows impaired activity for carbapenems but displays an enhanced hydrolysis of oxyimino-cephalosporins. Here, we address the mechanistic and structural basis for carbapenem hydrolysis by OXA-48-like enzymes. Pre-steady-state kinetic analysis indicates that the rate-limiting step for OXA-48 and OXA-163 hydrolysis of carbapenems is deacylation and that the greatly reduced carbapenemase activity of OXA-163 compared to that of OXA-48 is due entirely to a slower deacylation reaction. Furthermore, our structural data indicate that the positioning of the β5-β6 loop is necessary for carbapenem hydrolysis by OXA-48. A major difference between the OXA-48 and OXA-163 complexes with carbapenems is that the 214-RIEP-217 deletion in OXA-163 creates a large opening in the active site that is absent in the OXA-48/carbapenem structures. We propose that the larger active site results in less constraint on the conformation of the 6α-hydroxyethyl group in the acyl-enzyme. The acyl-enzyme intermediate assumes multiple conformations, most of which are incompatible with rapid deacylation. Consistent with this hypothesis, molecular dynamics simulations indicate that the most stable complex is formed between OXA-48 and imipenem, which correlates with the OXA-48 hydrolysis of imipenem being the fastest observed. Furthermore, the OXA-163 complexes with imipenem and meropenem are the least stable and show significant conformational fluctuations, which correlates with the slow hydrolysis of these substrates.
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Affiliation(s)
| | | | - Banumathi Sankaran
- Department of Molecular Biophysics and Integrated Bioimaging, Berkeley Center for Structural Biology, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States,
| | - Feng Wang
- Department of Chemistry, Center for Research Computing, Center for Drug Discovery, Design, and Delivery (CD4), Southern Methodist University, Dallas, Texas 75205, United States
| | - Peng Tao
- Department of Chemistry, Center for Research Computing, Center for Drug Discovery, Design, and Delivery (CD4), Southern Methodist University, Dallas, Texas 75205, United States
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16
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Hujer AM, Hujer KM, Leonard DA, Powers RA, Wallar BJ, Mack AR, Taracila MA, Rather PN, Higgins PG, Prati F, Caselli E, Marshall SH, Clarke T, Greco C, Venepally P, Brinkac L, Kreiswirth BN, Fouts DE, Bonomo RA. A comprehensive and contemporary "snapshot" of β-lactamases in carbapenem resistant Acinetobacter baumannii. Diagn Microbiol Infect Dis 2020; 99:115242. [PMID: 33248392 PMCID: PMC7562987 DOI: 10.1016/j.diagmicrobio.2020.115242] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 09/23/2020] [Accepted: 10/10/2020] [Indexed: 10/30/2022]
Abstract
Successful treatment of Acinetobacter baumannii infections require early and appropriate antimicrobial therapy. One of the first steps in this process is understanding which β-lactamase (bla) alleles are present and in what combinations. Thus, we performed WGS on 98 carbapenem-resistant A. baumannii (CR Ab). In most isolates, an acquired blaOXA carbapenemase was found in addition to the intrinsic blaOXA allele. The most commonly found allele was blaOXA-23 (n = 78/98). In some isolates, blaOXA-23 was found in addition to other carbapenemase alleles: blaOXA-82 (n = 12/78), blaOXA-72 (n = 2/78) and blaOXA-24/40 (n = 1/78). Surprisingly, 20% of isolates carried carbapenemases not routinely assayed for by rapid molecular diagnostic platforms, i.e., blaOXA-82 and blaOXA-172; all had ISAba1 elements. In 8 CR Ab, blaOXA-82 or blaOXA-172 was the only carbapenemase. Both blaOXA-24/40 and its variant blaOXA-72 were each found in 6/98 isolates. The most prevalent ADC variants were blaADC-30 (21%), blaADC-162 (21%), and blaADC-212 (26%). Complete combinations are reported.
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Affiliation(s)
- Andrea M Hujer
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH, USA; Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, USA
| | - Kristine M Hujer
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH, USA; Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, USA
| | - David A Leonard
- Department of Chemistry, Grand Valley State University, Allendale, MI, USA
| | - Rachel A Powers
- Department of Chemistry, Grand Valley State University, Allendale, MI, USA
| | - Bradley J Wallar
- Department of Chemistry, Grand Valley State University, Allendale, MI, USA
| | - Andrew R Mack
- Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, USA; Department of Molecular Biology and Microbiology, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Magdalena A Taracila
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH, USA; Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, USA
| | - Philip N Rather
- Research Service, Atlanta Veterans Medical Center, Decatur, GA, USA; Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA, USA; Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA, USA
| | - Paul G Higgins
- Institute for Medical Microbiology, Immunology and Hygiene, University of Cologne, Cologne, Germany; German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, Germany
| | - Fabio Prati
- Department of Life Science, University of Modena and Reggio Emilia, Modena, Italy
| | - Emilia Caselli
- Department of Life Science, University of Modena and Reggio Emilia, Modena, Italy
| | - Steven H Marshall
- Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, USA
| | | | | | | | | | - Barry N Kreiswirth
- Hackensack Meridian Health, Center for Discovery and Innovation, Nutley, NJ, USA
| | | | - Robert A Bonomo
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH, USA; Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, USA; Department of Molecular Biology and Microbiology, Case Western Reserve University School of Medicine, Cleveland, OH, USA; Departments of Biochemistry, Pharmacology, and Proteomics and Bioinformatics, Case Western Reserve University School of Medicine, Cleveland, OH, USA; CWRU-Cleveland VAMC Center for Antimicrobial Resistance and Epidemiology (Case VA CARES) Cleveland, OH, USA.
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17
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Insight into the significant roles of the Trp372 and flexible loop in directing the catalytic direction and substrate specificity in AGE superfamily enzymes. Biochem Eng J 2020. [DOI: 10.1016/j.bej.2020.107662] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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18
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Ding Y, Li Z, Xu C, Qin W, Wu Q, Wang X, Cheng X, Li L, Huang W. Fluorogenic Probes/Inhibitors of β-Lactamase and their Applications in Drug-Resistant Bacteria. Angew Chem Int Ed Engl 2020; 60:24-40. [PMID: 32592283 DOI: 10.1002/anie.202006635] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Indexed: 01/08/2023]
Abstract
β-Lactam antibiotics are generally perceived as one of the greatest inventions of the 20th century, and these small molecular compounds have saved millions of lives. However, upon clinical application of antibiotics, the β-lactamase secreted by pathogenic bacteria can lead to the gradual development of drug resistance. β-Lactamase is a hydrolase that can efficiently hydrolyze and destroy β-lactam antibiotics. It develops and spreads rapidly in pathogens, and the drug-resistant bacteria pose a severe threat to human health and development. As a result, detecting and inhibiting the activities of β-lactamase are of great value for the rational use of antibiotics and the treatment of infectious diseases. At present, many specific detection methods and inhibitors of β-lactamase have been developed and applied in clinical practice. In this Minireview, we describe the resistance mechanism of bacteria producing β-lactamase and further summarize the fluorogenic probes, inhibitors of β-lactamase, and their applications in the treatment of infectious diseases. It may be valuable to design fluorogenic probes with improved selectivity, sensitivity, and effectiveness to further identify the inhibitors for β-lactamases and eventually overcome bacterial resistance.
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Affiliation(s)
- Yang Ding
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), Nanjing, 211816, P. R. China
| | - Zheng Li
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), Nanjing, 211816, P. R. China
| | - Chenchen Xu
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), Nanjing, 211816, P. R. China
| | - Wenjing Qin
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), Nanjing, 211816, P. R. China
| | - Qiong Wu
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), Nanjing, 211816, P. R. China
| | - Xuchun Wang
- College of Chemistry and Material Engineering, University of Science and Technology of Anhui, Bengbu, 233000, P. R. China
| | - Xiamin Cheng
- Institute of Advanced Synthesis, School of Chemistry and Molecular Engineering, Nanjing Tech University (NanjingTech), Nanjing, 211816, P. R. China
| | - Lin Li
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), Nanjing, 211816, P. R. China
| | - Wei Huang
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), Nanjing, 211816, P. R. China.,Frontiers Science Center for Flexible Electronics (FSCFE), Shaanxi Institute of Flexible Electronics (SIFE) & Shaanxi Institute of Biomedical Materials and Engineering (SIBME), Northwestern Polytechnical University (NPU), Xi'an, 710072, P. R. China
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19
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Ding Y, Li Z, Xu C, Qin W, Wu Q, Wang X, Cheng X, Li L, Huang W. Fluorogenic Probes/Inhibitors of β‐Lactamase and their Applications in Drug‐Resistant Bacteria. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202006635] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Yang Ding
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM) Nanjing Tech University (NanjingTech) Nanjing 211816 P. R. China
| | - Zheng Li
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM) Nanjing Tech University (NanjingTech) Nanjing 211816 P. R. China
| | - Chenchen Xu
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM) Nanjing Tech University (NanjingTech) Nanjing 211816 P. R. China
| | - Wenjing Qin
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM) Nanjing Tech University (NanjingTech) Nanjing 211816 P. R. China
| | - Qiong Wu
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM) Nanjing Tech University (NanjingTech) Nanjing 211816 P. R. China
| | - Xuchun Wang
- College of Chemistry and Material Engineering University of Science and Technology of Anhui Bengbu 233000 P. R. China
| | - Xiamin Cheng
- Institute of Advanced Synthesis School of Chemistry and Molecular Engineering Nanjing Tech University (NanjingTech) Nanjing 211816 P. R. China
| | - Lin Li
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM) Nanjing Tech University (NanjingTech) Nanjing 211816 P. R. China
| | - Wei Huang
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM) Nanjing Tech University (NanjingTech) Nanjing 211816 P. R. China
- Frontiers Science Center for Flexible Electronics (FSCFE) Shaanxi Institute of Flexible Electronics (SIFE) & Shaanxi Institute of Biomedical Materials and Engineering (SIBME) Northwestern Polytechnical University (NPU) Xi'an 710072 P. R. China
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20
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Crean RM, Gardner JM, Kamerlin SCL. Harnessing Conformational Plasticity to Generate Designer Enzymes. J Am Chem Soc 2020; 142:11324-11342. [PMID: 32496764 PMCID: PMC7467679 DOI: 10.1021/jacs.0c04924] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Indexed: 02/08/2023]
Abstract
Recent years have witnessed an explosion of interest in understanding the role of conformational dynamics both in the evolution of new enzymatic activities from existing enzymes and in facilitating the emergence of enzymatic activity de novo on scaffolds that were previously non-catalytic. There are also an increasing number of examples in the literature of targeted engineering of conformational dynamics being successfully used to alter enzyme selectivity and activity. Despite the obvious importance of conformational dynamics to both enzyme function and evolvability, many (although not all) computational design approaches still focus either on pure sequence-based approaches or on using structures with limited flexibility to guide the design. However, there exist a wide variety of computational approaches that can be (re)purposed to introduce conformational dynamics as a key consideration in the design process. Coupled with laboratory evolution and more conventional existing sequence- and structure-based approaches, these techniques provide powerful tools for greatly expanding the protein engineering toolkit. This Perspective provides an overview of evolutionary studies that have dissected the role of conformational dynamics in facilitating the emergence of novel enzymes, as well as advances in computational approaches that allow one to target conformational dynamics as part of enzyme design. Harnessing conformational dynamics in engineering studies is a powerful paradigm with which to engineer the next generation of designer biocatalysts.
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Affiliation(s)
- Rory M. Crean
- Department of Chemistry -
BMC, Uppsala University, Box 576, 751 23 Uppsala, Sweden
| | - Jasmine M. Gardner
- Department of Chemistry -
BMC, Uppsala University, Box 576, 751 23 Uppsala, Sweden
| | - Shina C. L. Kamerlin
- Department of Chemistry -
BMC, Uppsala University, Box 576, 751 23 Uppsala, Sweden
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21
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Dabos L, Zavala A, Bonnin RA, Beckstein O, Retailleau P, Iorga BI, Naas T. Substrate Specificity of OXA-48 after β5-β6 Loop Replacement. ACS Infect Dis 2020; 6:1032-1043. [PMID: 32156115 DOI: 10.1021/acsinfecdis.9b00452] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
OXA-48 carbapenemase has rapidly spread in many countries worldwide with several OXA-48-variants being described, differing by a few amino acid (AA) substitutions or deletions, mostly in the β5-β6 loop. While single AA substitutions have only a minor impact on OXA-48 hydrolytic profiles, others with 4 AA deletions result in loss of carbapenem hydrolysis and gain of expanded-spectrum cephalosporin (ESC) hydrolysis. We have replaced the β5-β6 loop of OXA-48 with that of OXA-18, a clavulanic-acid inhibited oxacillinase capable of hydrolyzing ESCs but not carbapenems. The hybrid enzyme OXA-48Loop18 was able to hydrolyze ESCs and carbapenems (although with a lower kcat), even though the β5-β6 loop was longer and its sequence quite different from that of OXA-48. The kinetic parameters of OXA-48Loop18 were in agreement with the MIC values. X-ray crystallography and molecular modeling suggest that the conformation of the grafted loop allows the binding of bulkier substrates, unlike that of the native loop, expanding the hydrolytic profile. This seems to be due not only to differences in AA sequence, but also to the backbone conformation the loop can adopt. Finally, our results provide further experimental evidence for the role of the β5-β6 loop in substrate selectivity of OXA-48-like enzymes and additional details on the structure-function relationship of β-lactamases, demonstrating how localized changes in these proteins can alter or expand their function, highlighting their plasticity.
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Affiliation(s)
- Laura Dabos
- EA7361 “Structure, Dynamic, Function and Expression of Broad Spectrum β-Lactamases”, Université Paris Sud, Université Paris Saclay, LabEx Lermit, Faculty of Medicine, 94270 Le Kremlin-Bicêtre, France
- Evolution and Ecology of Resistance to Antibiotics Unit, Institut Pasteur−APHP−Université Paris Sud, 75015 Paris, France
| | - Agustin Zavala
- Institut de Chimie des Substances Naturelles, CNRS UPR 2301, Université Paris-Saclay, Labex LERMIT, 91190 Gif-sur-Yvette, France
| | - Rémy A. Bonnin
- EA7361 “Structure, Dynamic, Function and Expression of Broad Spectrum β-Lactamases”, Université Paris Sud, Université Paris Saclay, LabEx Lermit, Faculty of Medicine, 94270 Le Kremlin-Bicêtre, France
- Evolution and Ecology of Resistance to Antibiotics Unit, Institut Pasteur−APHP−Université Paris Sud, 75015 Paris, France
- Associated French National Reference Center for Antibiotic Resistance: Carbapenemase-Producing Enterobacteriaceae, 94270 Le Kremlin-Bicêtre, France
| | - Oliver Beckstein
- Department of Physics and Center for Biological Physics, Arizona State University, Tempe, 85281 Arizona, United States
| | - Pascal Retailleau
- Institut de Chimie des Substances Naturelles, CNRS UPR 2301, Université Paris-Saclay, Labex LERMIT, 91190 Gif-sur-Yvette, France
| | - Bogdan I. Iorga
- Institut de Chimie des Substances Naturelles, CNRS UPR 2301, Université Paris-Saclay, Labex LERMIT, 91190 Gif-sur-Yvette, France
| | - Thierry Naas
- EA7361 “Structure, Dynamic, Function and Expression of Broad Spectrum β-Lactamases”, Université Paris Sud, Université Paris Saclay, LabEx Lermit, Faculty of Medicine, 94270 Le Kremlin-Bicêtre, France
- Evolution and Ecology of Resistance to Antibiotics Unit, Institut Pasteur−APHP−Université Paris Sud, 75015 Paris, France
- Associated French National Reference Center for Antibiotic Resistance: Carbapenemase-Producing Enterobacteriaceae, 94270 Le Kremlin-Bicêtre, France
- Bacteriology-Hygiene Unit, Assistance Publique/Hôpitaux de Paris, Bicêtre Hospital, 94270 Le Kremlin-Bicêtre, France
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22
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Hirvonen VHA, Mulholland AJ, Spencer J, van der Kamp MW. Small Changes in Hydration Determine Cephalosporinase Activity of OXA-48 β-Lactamases. ACS Catal 2020. [DOI: 10.1021/acscatal.0c00596] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Viivi H. A. Hirvonen
- School of Biochemistry, University of Bristol, University Walk, Bristol, BS8 1TD United Kingdom
- Centre for Computational Chemistry, School of Chemistry, University of Bristol, Cantock’s Close, Bristol, BS8 1TS United Kingdom
| | - Adrian J. Mulholland
- Centre for Computational Chemistry, School of Chemistry, University of Bristol, Cantock’s Close, Bristol, BS8 1TS United Kingdom
| | - James Spencer
- School of Cellular and Molecular Medicine, University of Bristol, University Walk, Bristol, BS8 1TD United Kingdom
| | - Marc W. van der Kamp
- School of Biochemistry, University of Bristol, University Walk, Bristol, BS8 1TD United Kingdom
- Centre for Computational Chemistry, School of Chemistry, University of Bristol, Cantock’s Close, Bristol, BS8 1TS United Kingdom
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23
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Structural Analysis of The OXA-48 Carbapenemase Bound to A "Poor" Carbapenem Substrate, Doripenem. Antibiotics (Basel) 2019; 8:antibiotics8030145. [PMID: 31514291 PMCID: PMC6783824 DOI: 10.3390/antibiotics8030145] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 08/30/2019] [Accepted: 09/04/2019] [Indexed: 12/11/2022] Open
Abstract
Carbapenem-resistant Enterobacteriaceae are a significant threat to public health, and a major resistance determinant that promotes this phenotype is the production of the OXA-48 carbapenemase. The activity of OXA-48 towards carbapenems is a puzzling phenotype as its hydrolytic activity against doripenem is non-detectable. To probe the mechanistic basis for this observation, we determined the 1.5 Å resolution crystal structure of the deacylation deficient K73A variant of OXA-48 in complex with doripenem. Doripenem is observed in the Δ1R and Δ1S tautomeric states covalently attached to the catalytic S70 residue. Likely due to positioning of residue Y211, the carboxylate moiety of doripenem is making fewer hydrogen bonding/salt-bridge interactions with R250 compared to previously determined carbapenem OXA structures. Moreover, the hydroxyethyl side chain of doripenem is making van der Waals interactions with a key V120 residue, which likely affects the deacylation rate of doripenem. We hypothesize that positions V120 and Y211 play important roles in the carbapenemase profile of OXA-48. Herein, we provide insights for the further development of the carbapenem class of antibiotics that could render them less effective to hydrolysis by or even inhibit OXA carbapenemases.
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24
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Tooke CL, Hinchliffe P, Bragginton EC, Colenso CK, Hirvonen VHA, Takebayashi Y, Spencer J. β-Lactamases and β-Lactamase Inhibitors in the 21st Century. J Mol Biol 2019; 431:3472-3500. [PMID: 30959050 PMCID: PMC6723624 DOI: 10.1016/j.jmb.2019.04.002] [Citation(s) in RCA: 440] [Impact Index Per Article: 88.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 03/27/2019] [Accepted: 04/01/2019] [Indexed: 12/31/2022]
Abstract
The β-lactams retain a central place in the antibacterial armamentarium. In Gram-negative bacteria, β-lactamase enzymes that hydrolyze the amide bond of the four-membered β-lactam ring are the primary resistance mechanism, with multiple enzymes disseminating on mobile genetic elements across opportunistic pathogens such as Enterobacteriaceae (e.g., Escherichia coli) and non-fermenting organisms (e.g., Pseudomonas aeruginosa). β-Lactamases divide into four classes; the active-site serine β-lactamases (classes A, C and D) and the zinc-dependent or metallo-β-lactamases (MBLs; class B). Here we review recent advances in mechanistic understanding of each class, focusing upon how growing numbers of crystal structures, in particular for β-lactam complexes, and methods such as neutron diffraction and molecular simulations, have improved understanding of the biochemistry of β-lactam breakdown. A second focus is β-lactamase interactions with carbapenems, as carbapenem-resistant bacteria are of grave clinical concern and carbapenem-hydrolyzing enzymes such as KPC (class A) NDM (class B) and OXA-48 (class D) are proliferating worldwide. An overview is provided of the changing landscape of β-lactamase inhibitors, exemplified by the introduction to the clinic of combinations of β-lactams with diazabicyclooctanone and cyclic boronate serine β-lactamase inhibitors, and of progress and strategies toward clinically useful MBL inhibitors. Despite the long history of β-lactamase research, we contend that issues including continuing unresolved questions around mechanism; opportunities afforded by new technologies such as serial femtosecond crystallography; the need for new inhibitors, particularly for MBLs; the likely impact of new β-lactam:inhibitor combinations and the continuing clinical importance of β-lactams mean that this remains a rewarding research area.
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Affiliation(s)
- Catherine L Tooke
- School of Cellular and Molecular Medicine, University of Bristol Biomedical Sciences Building, University Walk, Bristol BS8 1TD, United Kingdom
| | - Philip Hinchliffe
- School of Cellular and Molecular Medicine, University of Bristol Biomedical Sciences Building, University Walk, Bristol BS8 1TD, United Kingdom
| | - Eilis C Bragginton
- School of Cellular and Molecular Medicine, University of Bristol Biomedical Sciences Building, University Walk, Bristol BS8 1TD, United Kingdom
| | - Charlotte K Colenso
- School of Cellular and Molecular Medicine, University of Bristol Biomedical Sciences Building, University Walk, Bristol BS8 1TD, United Kingdom
| | - Viivi H A Hirvonen
- School of Cellular and Molecular Medicine, University of Bristol Biomedical Sciences Building, University Walk, Bristol BS8 1TD, United Kingdom
| | - Yuiko Takebayashi
- School of Cellular and Molecular Medicine, University of Bristol Biomedical Sciences Building, University Walk, Bristol BS8 1TD, United Kingdom
| | - James Spencer
- School of Cellular and Molecular Medicine, University of Bristol Biomedical Sciences Building, University Walk, Bristol BS8 1TD, United Kingdom.
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25
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Zeuner B, Teze D, Muschiol J, Meyer AS. Synthesis of Human Milk Oligosaccharides: Protein Engineering Strategies for Improved Enzymatic Transglycosylation. Molecules 2019; 24:E2033. [PMID: 31141914 PMCID: PMC6600218 DOI: 10.3390/molecules24112033] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 05/24/2019] [Accepted: 05/26/2019] [Indexed: 12/18/2022] Open
Abstract
Human milk oligosaccharides (HMOs) signify a unique group of oligosaccharides in breast milk, which is of major importance for infant health and development. The functional benefits of HMOs create an enormous impetus for biosynthetic production of HMOs for use as additives in infant formula and other products. HMO molecules can be synthesized chemically, via fermentation, and by enzymatic synthesis. This treatise discusses these different techniques, with particular focus on harnessing enzymes for controlled enzymatic synthesis of HMO molecules. In order to foster precise and high-yield enzymatic synthesis, several novel protein engineering approaches have been reported, mainly concerning changing glycoside hydrolases to catalyze relevant transglycosylations. The protein engineering strategies for these enzymes range from rationally modifying specific catalytic residues, over targeted subsite -1 mutations, to unique and novel transplantations of designed peptide sequences near the active site, so-called loop engineering. These strategies have proven useful to foster enhanced transglycosylation to promote different types of HMO synthesis reactions. The rationale of subsite -1 modification, acceptor binding site matching, and loop engineering, including changes that may alter the spatial arrangement of water in the enzyme active site region, may prove useful for novel enzyme-catalyzed carbohydrate design in general.
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Affiliation(s)
- Birgitte Zeuner
- Protein Chemistry and Enzyme Technology, Department of Biotechnology and Biomedicine, Technical University of Denmark, 2800 Kgs Lyngby, Denmark.
| | - David Teze
- Protein Chemistry and Enzyme Technology, Department of Biotechnology and Biomedicine, Technical University of Denmark, 2800 Kgs Lyngby, Denmark.
| | - Jan Muschiol
- Protein Chemistry and Enzyme Technology, Department of Biotechnology and Biomedicine, Technical University of Denmark, 2800 Kgs Lyngby, Denmark.
| | - Anne S Meyer
- Protein Chemistry and Enzyme Technology, Department of Biotechnology and Biomedicine, Technical University of Denmark, 2800 Kgs Lyngby, Denmark.
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26
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Characterization of the First OXA-10 Natural Variant with Increased Carbapenemase Activity. Antimicrob Agents Chemother 2018; 63:AAC.01817-18. [PMID: 30397053 DOI: 10.1128/aac.01817-18] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Accepted: 10/26/2018] [Indexed: 12/25/2022] Open
Abstract
While carbapenem resistance in Gram-negative bacteria is mainly due to the production of efficient carbapenemases, β-lactamases with a narrower spectrum may also contribute to resistance when combined with additional mechanisms. OXA-10-type class D β-lactamases, previously shown to be weak carbapenemases, could represent such a case. In this study, two novel OXA-10 variants were identified as the sole carbapenem-hydrolyzing enzymes in meropenem-resistant enterobacteria isolated from hospital wastewater and found by next-generation sequencing to express additional β-lactam resistance mechanisms. The new variants, OXA-655 and OXA-656, were carried by two related IncQ1 broad-host-range plasmids. Compared to the sequence of OXA-10, they both harbored a Thr26Met substitution, with OXA-655 also bearing a leucine instead of a valine in position 117 of the SAV catalytic motif. Susceptibility profiling of laboratory strains replicating the natural bla OXA plasmids and of recombinant clones expressing OXA-10 and the novel variants in an isogenic background indicated that OXA-655 is a more efficient carbapenemase. The carbapenemase activity of OXA-655 is due to the Val117Leu substitution, as shown by steady-state kinetic experiments, where the k cat of meropenem hydrolysis was increased 4-fold. In contrast, OXA-655 had no activity toward oxyimino-β-lactams, while its catalytic efficiency against oxacillin was significantly reduced. Moreover, the Val117Leu variant was more efficient against temocillin and cefoxitin. Molecular dynamics indicated that Val117Leu affects the position 117-Leu155 interaction, leading to structural shifts in the active site that may alter carbapenem alignment. The evolutionary potential of OXA-10 enzymes toward carbapenem hydrolysis combined with their spread by promiscuous plasmids indicates that they may pose a future clinical threat.
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27
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Genetic and Biochemical Characterization of OXA-519, a Novel OXA-48-Like β-Lactamase. Antimicrob Agents Chemother 2018; 62:AAC.00469-18. [PMID: 29866857 DOI: 10.1128/aac.00469-18] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 05/25/2018] [Indexed: 01/31/2023] Open
Abstract
A multidrug-resistant Klebsiella pneumoniae 1210 isolate with reduced carbapenem susceptibility revealed the presence of a novel plasmid-encoded blaOXA-48-like gene, named blaOXA-519 The 60.7-kb plasmid (pOXA-519) was similar to the IncL-OXA-48 prototypical plasmid except for a ca. 2-kb deletion due to an IS1R insertion. OXA-519 differed from OXA-48 by a Val120Leu substitution, which resulted in an overall reduced β-lactam-hydrolysis profile, except those for ertapenem and meropenem, which were increased. Thus, detection of OXA-519 producers using biochemical tests that monitor imipenem hydrolysis will be difficult.
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28
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Frederick TE, Peng JW. A gratuitous β-Lactamase inducer uncovers hidden active site dynamics of the Staphylococcus aureus BlaR1 sensor domain. PLoS One 2018; 13:e0197241. [PMID: 29771929 PMCID: PMC5957439 DOI: 10.1371/journal.pone.0197241] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Accepted: 04/28/2018] [Indexed: 11/18/2022] Open
Abstract
Increasing evidence shows that active sites of proteins have non-trivial conformational dynamics. These dynamics include active site residues sampling different local conformations that allow for multiple, and possibly novel, inhibitor binding poses. Yet, active site dynamics garner only marginal attention in most inhibitor design efforts and exert little influence on synthesis strategies. This is partly because synthesis requires a level of atomic structural detail that is frequently missing in current characterizations of conformational dynamics. In particular, while the identity of the mobile protein residues may be clear, the specific conformations they sample remain obscure. Here, we show how an appropriate choice of ligand can significantly sharpen our abilities to describe the interconverting binding poses (conformations) of protein active sites. Specifically, we show how 2-(2'-carboxyphenyl)-benzoyl-6-aminopenicillanic acid (CBAP) exposes otherwise hidden dynamics of a protein active site that binds β-lactam antibiotics. When CBAP acylates (binds) the active site serine of the β-lactam sensor domain of BlaR1 (BlaRS), it shifts the time scale of the active site dynamics to the slow exchange regime. Slow exchange enables direct characterization of inter-converting protein and bound ligand conformations using NMR methods. These methods include chemical shift analysis, 2-d exchange spectroscopy, off-resonance ROESY of the bound ligand, and reduced spectral density mapping. The active site architecture of BlaRS is shared by many β-lactamases of therapeutic interest, suggesting CBAP could expose functional motions in other β-lactam binding proteins. More broadly, CBAP highlights the utility of identifying chemical probes common to structurally homologous proteins to better expose functional motions of active sites.
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Affiliation(s)
- Thomas E. Frederick
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States of America
| | - Jeffrey W. Peng
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States of America
- Department of Physics, University of Notre Dame, Notre Dame, IN, United States of America
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29
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Staude MW, Leonard DA, Peng JW. Expanded Substrate Activity of OXA-24/40 in Carbapenem-Resistant Acinetobacter baumannii Involves Enhanced Binding Loop Flexibility. Biochemistry 2016; 55:6535-6544. [DOI: 10.1021/acs.biochem.6b00806] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Michael W. Staude
- Department
of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - David A. Leonard
- Department
of Chemistry, Grand Valley State University, Allendale, Michigan 49401, United States
| | - Jeffrey W. Peng
- Department
of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
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30
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Simakov N, Leonard DA, Smith JC, Wymore T, Szarecka A. A Distal Disulfide Bridge in OXA-1 β-Lactamase Stabilizes the Catalytic Center and Alters the Dynamics of the Specificity Determining Ω Loop. J Phys Chem B 2016; 121:3285-3296. [PMID: 27668669 DOI: 10.1021/acs.jpcb.6b07884] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Widespread antibiotic resistance, particularly when mediated by broad-spectrum β-lactamases, has major implications for public health. Substitutions in the active site often allow broad-spectrum enzymes to accommodate diverse types of β-lactams. Substitutions observed outside the active site are thought to compensate for the loss of thermal stability. The OXA-1 clade of class D β-lactamases contains a pair of conserved cysteines located outside the active site that forms a disulfide bond in the periplasm. Here, the effect of the distal disulfide bond on the structure and dynamics of OXA-1 was investigated via 4 μs molecular dynamics simulations. The results reveal that the disulfide promotes the preorganized orientation of the catalytic residues and affects the conformation of the functionally important Ω loop. Furthermore, principal component analysis reveals differences in the global dynamics between the oxidized and reduced forms, especially in the motions involving the Ω loop. A dynamical network analysis indicates that, in the oxidized form, in addition to its role in ligand binding, the KTG family motif is a central hub of the global dynamics. As activity of OXA-1 has been measured only in the reduced form, we suggest that accurate assessment of its functional profile would require oxidative conditions mimicking periplasm.
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Affiliation(s)
- Nikolay Simakov
- Carnegie Mellon University , Pittsburgh Supercomputing Center, Pittsburgh, Pennsylvania 15213, United States.,Center for Computational Research, SUNY at Buffalo , New York 14203, United States
| | | | - Jeremy C Smith
- Center for Molecular Biophysics, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
| | - Troy Wymore
- Center for Molecular Biophysics, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States.,Department of Chemistry, University of Michigan , Ann Arbor, Michigan 48109, United States
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31
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June CM, Muckenthaler TJ, Schroder EC, Klamer ZL, Wawrzak Z, Powers RA, Szarecka A, Leonard DA. The structure of a doripenem-bound OXA-51 class D β-lactamase variant with enhanced carbapenemase activity. Protein Sci 2016; 25:2152-2163. [PMID: 27636561 DOI: 10.1002/pro.3040] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 09/09/2016] [Accepted: 09/09/2016] [Indexed: 11/10/2022]
Abstract
OXA-51 is a class D β-lactamase that is thought to be the native carbapenemase of Acinetobacter baumannii. Many variants of OXA-51 containing active site substitutions have been identified from A. baumannii isolates, and some of these substitutions increase hydrolytic activity toward carbapenem antibiotics. We have determined the high-resolution structures of apo OXA-51 and OXA-51 with one such substitution (I129L) with the carbapenem doripenem trapped in the active site as an acyl-intermediate. The structure shows that acyl-doripenem adopts an orientation very similar to carbapenem ligands observed in the active site of OXA-24/40 (doripenem) and OXA-23 (meropenem). In the OXA-51 variant/doripenem complex, the indole ring of W222 is oriented away from the doripenem binding site, thereby eliminating a clash that is predicted to occur in wildtype OXA-51. Similarly, in the OXA-51 variant complex, L129 adopts a different rotamer compared to I129 in wildtype OXA-51. This alternative position moves its side chain away from the hydroxyethyl moiety of doripenem and relieves another potential clash between the enzyme and carbapenem substrates. Molecular dynamics simulations of OXA-51 and OXA-51 I129L demonstrate that compared to isoleucine, a leucine at this position greatly favors a rotamer that accommodates the ligand. These results provide a molecular justification for how this substitution generates enhanced binding affinity for carbapenems, and therefore helps explain the prevalence of this substitution in clinical OXA-51 variants.
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Affiliation(s)
- Cynthia M June
- Department of Chemistry, Grand Valley State University, Allendale, Michigan, 49401
| | | | - Emma C Schroder
- Department of Chemistry, Grand Valley State University, Allendale, Michigan, 49401
| | - Zachary L Klamer
- Department of Cell and Molecular Biology, Grand Valley State University, Allendale, Michigan, 49401
| | - Zdzislaw Wawrzak
- Life Sciences Collaborative Access Team, Synchrotron Research Center, Northwestern University, Argonne, Illinois, 60439
| | - Rachel A Powers
- Department of Chemistry, Grand Valley State University, Allendale, Michigan, 49401
| | - Agnieszka Szarecka
- Department of Cell and Molecular Biology, Grand Valley State University, Allendale, Michigan, 49401
| | - David A Leonard
- Department of Chemistry, Grand Valley State University, Allendale, Michigan, 49401
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32
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Clinical Variants of the Native Class D β-Lactamase of Acinetobacter baumannii Pose an Emerging Threat through Increased Hydrolytic Activity against Carbapenems. Antimicrob Agents Chemother 2016; 60:6155-64. [PMID: 27480863 DOI: 10.1128/aac.01277-16] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 07/26/2016] [Indexed: 11/20/2022] Open
Abstract
The threat posed by the chromosomally encoded class D β-lactamase of Acinetobacter baumannii (OXA-51/66) has been unclear, in part because of its relatively low affinity and turnover rate for carbapenems. Several hundred clinical variants of OXA-51/66 have been reported, many with substitutions of active-site residues. We determined the kinetic properties of OXA-66 and five clinical variants with respect to a wide variety of β-lactam substrates. The five variants displayed enhanced activity against carbapenems and in some cases against penicillins, late-generation cephalosporins, and the monobactam aztreonam. Molecular dynamics simulations show that in OXA-66, P130 inhibits the side-chain rotation of I129 and thereby prevents doripenem binding because of steric clash. A single amino acid substitution at this position (P130Q) in the variant OXA-109 greatly enhances the mobility of both I129 and a key active-site tryptophan (W222), thereby facilitating carbapenem binding. This expansion of substrate specificity represents a very worrisome development for the efficacy of β-lactams against this troublesome pathogen.
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33
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Structure-based approach for identification of novel phenylboronic acids as serine-β-lactamase inhibitors. J Comput Aided Mol Des 2016; 30:851-861. [DOI: 10.1007/s10822-016-9962-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 09/02/2016] [Indexed: 11/25/2022]
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34
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Pal A, Tripathi A. An in silico approach to elucidate structure based functional evolution of oxacillinase. Comput Biol Chem 2016; 64:145-153. [PMID: 27343874 DOI: 10.1016/j.compbiolchem.2016.06.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Revised: 05/25/2016] [Accepted: 06/06/2016] [Indexed: 11/25/2022]
Abstract
Bacterial Oxacillinases (OXAs), genetically being extremely diverse and highly versatile in hydrolyzing antibiotics of different classes, holds utmost significant clinical importance. Hence, to analyze functional evolution of this enzyme, plausible changes in drug profile, affinity and binding stability of different subclasses of OXA with their preferred drugs, viz. penicillin, ceftazidime, imipenem/meropenem were investigated. Maximum-Likelihood dendrogram was constructed and based on tree topology, the least and most divergent variants of each clade were selected. Pocket characterization, enzyme structural stability and mutational effect were analyzed in silico. Modes of interaction of selected OXA variants with respective antibiotics were analyzed by Autodock4.0 and LIGPLOT. Comparative mobility profiling and subsequent ΔG° and Km calculations of representative OXA variants revealed that after RSBL evolution, perhaps, two competitive strategies evolved among the OXA variants. Either loops flanking helix5 gets stabilized or it becomes more flexible. Therefore, while OXA variants (e.g. OXA-2, OXA-32, OXA-23, OXA-133, OXA-24, OXA-25, OXA-51 and OXA-75) with highly stabilized loops flanking helix5 exhibited improved binding stability and affinity towards carbapenems, especially meropenem, OXA variants (e.g. OXA-10, OXA-251, OXA-48 and OXA-247) possessing highly flexibile loops flanking helix5 revealed their catalytic proficiency towards ceftazidime. Moreover, LIGPLOT and PROMALS3D jointly identified ten consensuses/conserved residues, viz. P68, A69, F72, K73, W105, V120, W164, L169, K216 and G218 to be critical for drug hydrolysis. Hence, novel inhibitors could be designed to target these sites.
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Affiliation(s)
- Arijit Pal
- Department of Biochemistry and Medical Biotechnology, Calcutta School of Tropical Medicine, 108 C.R. Avenue, Kolkata 700073, India
| | - Anusri Tripathi
- Department of Biochemistry and Medical Biotechnology, Calcutta School of Tropical Medicine, 108 C.R. Avenue, Kolkata 700073, India.
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Vallejo JA, Martínez-Guitián M, Vázquez-Ucha JC, González-Bello C, Poza M, Buynak JD, Bethel CR, Bonomo RA, Bou G, Beceiro A. LN-1-255, a penicillanic acid sulfone able to inhibit the class D carbapenemase OXA-48. J Antimicrob Chemother 2016; 71:2171-80. [PMID: 27125555 DOI: 10.1093/jac/dkw105] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 03/04/2016] [Indexed: 01/06/2023] Open
Abstract
OBJECTIVES Carbapenemases are the most important mechanism responsible for carbapenem resistance in Enterobacteriaceae. Among carbapenemases, OXA-48 presents unique challenges as it is resistant to β-lactam inhibitors. Here, we test the capacity of the compound LN-1-255, a 6-alkylidene-2'-substituted penicillanic acid sulfone, to inhibit the activity of the carbapenemase OXA-48. METHODS The OXA-48 gene was cloned and expressed in Klebsiella pneumoniae and Escherichia coli in order to obtain MICs in the presence of inhibitors (clavulanic acid, tazobactam and sulbactam) and LN-1-255. OXA-48 was purified and steady-state kinetics was performed with LN-1-255 and tazobactam. The covalent binding mode of LN-1-255 with OXA-48 was studied by docking assays. RESULTS Both OXA-48-producing clinical and transformant strains displayed increased susceptibility to carbapenem antibiotics in the presence of 4 mg/L LN-1-255 (2-32-fold increased susceptibility) and 16 mg/L LN-1-255 (4-64-fold increased susceptibility). Kinetic assays demonstrated that LN-1-255 is able to inhibit OXA-48 with an acylation efficiency (k2/K) of 10 ± 1 × 10(4) M(-1) s(-1) and a slow deacylation rate (koff) of 7 ± 1 × 10(-4) s(-1). IC50 was 3 nM for LN-1-255 and 1.5 μM for tazobactam. Lastly, kcat/kinact was 500-fold lower for LN-1-255 than for tazobactam. CONCLUSIONS In these studies, carbapenem antibiotics used in combination with LN-1-255 are effective against the carbapenemase OXA-48, an important emerging mechanism of antibiotic resistance. This provides an incentive for further investigations to maximize the efficacy of penicillin sulfone inhibition of class D plasmid-carried Enterobacteriaceae carbapenemases.
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Affiliation(s)
- Juan A Vallejo
- Servicio de Microbiología-Instituto de Investigación Biomédica (INIBIC), 15006 A Coruña, Spain
| | - Marta Martínez-Guitián
- Servicio de Microbiología-Instituto de Investigación Biomédica (INIBIC), 15006 A Coruña, Spain
| | - Juan C Vázquez-Ucha
- Servicio de Microbiología-Instituto de Investigación Biomédica (INIBIC), 15006 A Coruña, Spain
| | - Concepción González-Bello
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS), Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Margarita Poza
- Servicio de Microbiología-Instituto de Investigación Biomédica (INIBIC), 15006 A Coruña, Spain
| | - John D Buynak
- Department of Chemistry, Southern Methodist University, Dallas, TX 75275, USA
| | - Christopher R Bethel
- Research Service, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH 44106, USA
| | - Robert A Bonomo
- Research Service, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH 44106, USA Departments of Biochemistry, Molecular Biology and Microbiology, Pharmacology and Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - German Bou
- Servicio de Microbiología-Instituto de Investigación Biomédica (INIBIC), 15006 A Coruña, Spain
| | - Alejandro Beceiro
- Servicio de Microbiología-Instituto de Investigación Biomédica (INIBIC), 15006 A Coruña, Spain
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Active-Site Plasticity Is Essential to Carbapenem Hydrolysis by OXA-58 Class D β-Lactamase of Acinetobacter baumannii. Antimicrob Agents Chemother 2015; 60:75-86. [PMID: 26459904 DOI: 10.1128/aac.01393-15] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2015] [Accepted: 10/03/2015] [Indexed: 01/09/2023] Open
Abstract
Carbapenem-hydrolyzing class D β-lactamases (CHDLs) are a subgroup of class D β-lactamases, which are enzymes that hydrolyze β-lactams. They have attracted interest due to the emergence of multidrug-resistant Acinetobacter baumannii, which is not responsive to treatment with carbapenems, the usual antibiotics of choice for this bacterium. Unlike other class D β-lactamases, these enzymes efficiently hydrolyze carbapenem antibiotics. To explore the structural requirements for the catalysis of carbapenems by these enzymes, we determined the crystal structure of the OXA-58 CHDL of A. baumannii following acylation of its active-site serine by a 6α-hydroxymethyl penicillin derivative that is a structural mimetic for a carbapenem. In addition, several point mutation variants of the active site of OXA-58, as identified by the crystal structure analysis, were characterized kinetically. These combined studies confirm the mechanistic relevance of a hydrophobic bridge formed over the active site. This structural feature is suggested to stabilize the hydrolysis-productive acyl-enzyme species formed from the carbapenem substrates of this enzyme. Furthermore, our structural studies provide strong evidence that the hydroxyethyl group of carbapenems samples different orientations in the active sites of CHDLs, and the optimum orientation for catalysis depends on the topology of the active site allowing proper closure of the active site. We propose that CHDLs use the plasticity of the active site to drive the mechanism of carbapenem hydrolysis toward efficiency.
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Yamamoto N, Hamaguchi S, Akeda Y, Santanirand P, Kerdsin A, Seki M, Ishii Y, Paveenkittiporn W, Bonomo RA, Oishi K, Malathum K, Tomono K. Clinical Specimen-Direct LAMP: A Useful Tool for the Surveillance of blaOXA-23-Positive Carbapenem-Resistant Acinetobacter baumannii. PLoS One 2015. [PMID: 26218925 PMCID: PMC4517775 DOI: 10.1371/journal.pone.0133204] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Healthcare-associated infections are a leading cause of morbidity and mortality worldwide. Treatment is increasingly complicated by the escalating incidence of antimicrobial resistance. Among drug-resistant pathogens, carbapenem-resistant Acinetobacter baumannii (CRAb) is of increasing concern because of the limited applicable therapies and its expanding global distribution in developed countries and newly industrialized countries. Therefore, a rapid detection method that can be used even in resource-poor countries is urgently required to control this global public health threat. Conventional techniques, such as bacterial culture and polymerase chain reaction (PCR), are insufficient to combat this threat because they are time-consuming and laborious. In this study, we developed a loop-mediated isothermal amplification (LAMP) method for detecting blaOXA-23-positive CRAb, the most prevalent form of CRAb in Asia, especially in Thailand, and confirmed its efficacy as a surveillance tool in a clinical setting. Clinical samples of sputum and rectal swabs were collected from patients in a hospital in Bangkok and used for LAMP assays. After boiling and centrifugation, the supernatants were used directly in the assay. In parallel, a culture method was used for comparison purposes to evaluate the specificity and sensitivity of LAMP. As a first step, a total of 120 sputum samples were collected. The sensitivity of LAMP was 88.6% (39/44), and its specificity was 92.1% (70/76) using the culture method as the “gold standard”. When surveillance samples including sputum and rectal swabs were analyzed with the LAMP assay, its sensitivity was 100.0%. This method enables the direct analysis of clinical specimens and provides results within 40 minutes of sample collection, making it a useful tool for surveillance even in resource-poor countries.
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Affiliation(s)
- Norihisa Yamamoto
- Division of Infection Control and Prevention, Osaka University Graduate School of Medicine, Osaka, Japan
- Laboratory of Clinical Research on Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Shigeto Hamaguchi
- Division of Infection Control and Prevention, Osaka University Graduate School of Medicine, Osaka, Japan
- Laboratory of Clinical Research on Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Yukihiro Akeda
- Division of Infection Control and Prevention, Osaka University Graduate School of Medicine, Osaka, Japan
- Laboratory of Clinical Research on Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Pitak Santanirand
- Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Anusak Kerdsin
- General Bacteriology Section, National Institute of Health, Department of Medical Sciences, Ministry of Public Health, Bangkok, Thailand
| | - Masafumi Seki
- Division of Infection Control and Prevention, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Yoshikazu Ishii
- Department of Microbiology and Infectious Diseases, School of Medicine, Faculty of Medicine, Toho University, Tokyo, Japan
| | - Wantana Paveenkittiporn
- General Bacteriology Section, National Institute of Health, Department of Medical Sciences, Ministry of Public Health, Bangkok, Thailand
| | - Robert A. Bonomo
- Research Service, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, Ohio, United States of America
| | - Kazunori Oishi
- Laboratory of Clinical Research on Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
- Infectious Disease Surveillance Center, National Institute of Infectious Diseases, Tokyo, Japan
| | - Kumthorn Malathum
- Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Kazunori Tomono
- Division of Infection Control and Prevention, Osaka University Graduate School of Medicine, Osaka, Japan
- * E-mail:
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Antonelli A, D'Andrea MM, Vaggelli G, Docquier JD, Rossolini GM. OXA-372, a novel carbapenem-hydrolysing class D β-lactamase from aCitrobacter freundiiisolated from a hospital wastewater plant. J Antimicrob Chemother 2015; 70:2749-56. [DOI: 10.1093/jac/dkv181] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 06/03/2015] [Indexed: 11/13/2022] Open
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39
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Stojanoski V, Chow DC, Fryszczyn B, Hu L, Nordmann P, Poirel L, Sankaran B, Prasad BVV, Palzkill T. Structural Basis for Different Substrate Profiles of Two Closely Related Class D β-Lactamases and Their Inhibition by Halogens. Biochemistry 2015; 54:3370-80. [PMID: 25938261 DOI: 10.1021/acs.biochem.5b00298] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
OXA-163 and OXA-48 are closely related class D β-lactamases that exhibit different substrate profiles. OXA-163 hydrolyzes oxyimino-cephalosporins, particularly ceftazidime, while OXA-48 prefers carbapenem substrates. OXA-163 differs from OXA-48 by one substitution (S212D) in the active-site β5 strand and a four-amino acid deletion (214-RIEP-217) in the loop connecting the β5 and β6 strands. Although the structure of OXA-48 has been determined, the structure of OXA-163 is unknown. To further understand the basis for their different substrate specificities, we performed enzyme kinetic analysis, inhibition assays, X-ray crystallography, and molecular modeling. The results confirm the carbapenemase nature of OXA-48 and the ability of OXA-163 to hydrolyze the oxyimino-cephalosporin ceftazidime. The crystal structure of OXA-163 determined at 1.72 Å resolution reveals an expanded active site compared to that of OXA-48, which allows the bulky substrate ceftazidime to be accommodated. The structural differences with OXA-48, which cannot hydrolyze ceftazidime, provide a rationale for the change in substrate specificity between the enzymes. OXA-163 also crystallized under another condition that included iodide. The crystal structure determined at 2.87 Å resolution revealed iodide in the active site accompanied by several significant conformational changes, including a distortion of the β5 strand, decarboxylation of Lys73, and distortion of the substrate-binding site. Further studies showed that both OXA-163 and OXA-48 are inhibited in the presence of iodide. In addition, OXA-10, which is not a member of the OXA-48-like family, is also inhibited by iodide. These findings provide a molecular basis for the hydrolysis of ceftazidime by OXA-163 and, more broadly, show how minor sequence changes can profoundly alter the active-site configuration and thereby affect the substrate profile of an enzyme.
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Affiliation(s)
| | | | | | | | - Patrice Nordmann
- §Medical and Molecular Microbiology "Emerging Antibiotic Resistance" Unit, Department of Medicine, Faculty of Science, University of Fribourg, 1700 Fribourg, Switzerland
| | - Laurent Poirel
- §Medical and Molecular Microbiology "Emerging Antibiotic Resistance" Unit, Department of Medicine, Faculty of Science, University of Fribourg, 1700 Fribourg, Switzerland
| | - Banumathi Sankaran
- ∥Berkeley Center for Structural Biology, Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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40
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Antonelli A, Di Palo DM, Galano A, Becciani S, Montagnani C, Pecile P, Galli L, Rossolini GM. Intestinal carriage of Shewanella xiamenensis simulating carriage of OXA-48–producing Enterobacteriaceae. Diagn Microbiol Infect Dis 2015; 82:1-3. [DOI: 10.1016/j.diagmicrobio.2015.02.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Revised: 02/13/2015] [Accepted: 02/17/2015] [Indexed: 11/16/2022]
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41
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Structural basis for carbapenem-hydrolyzing mechanisms of carbapenemases conferring antibiotic resistance. Int J Mol Sci 2015; 16:9654-92. [PMID: 25938965 PMCID: PMC4463611 DOI: 10.3390/ijms16059654] [Citation(s) in RCA: 107] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Revised: 04/21/2015] [Accepted: 04/22/2015] [Indexed: 02/06/2023] Open
Abstract
Carbapenems (imipenem, meropenem, biapenem, ertapenem, and doripenem) are β-lactam antimicrobial agents. Because carbapenems have the broadest spectra among all β-lactams and are primarily used to treat infections by multi-resistant Gram-negative bacteria, the emergence and spread of carbapenemases became a major public health concern. Carbapenemases are the most versatile family of β-lactamases that are able to hydrolyze carbapenems and many other β-lactams. According to the dependency of divalent cations for enzyme activation, carbapenemases can be divided into metallo-carbapenemases (zinc-dependent class B) and non-metallo-carbapenemases (zinc-independent classes A, C, and D). Many studies have provided various carbapenemase structures. Here we present a comprehensive and systematic review of three-dimensional structures of carbapenemase-carbapenem complexes as well as those of carbapenemases. We update recent studies in understanding the enzymatic mechanism of each class of carbapenemase, and summarize structural insights about regions and residues that are important in acquiring the carbapenemase activity.
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42
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Genetic and biochemical characterization of OXA-405, an OXA-48-type extended-spectrum β-lactamase without significant carbapenemase activity. Antimicrob Agents Chemother 2015; 59:3823-8. [PMID: 25870062 DOI: 10.1128/aac.05058-14] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 04/05/2015] [Indexed: 12/19/2022] Open
Abstract
The epidemiology of carbapenemases worldwide is showing that OXA-48 variants are becoming the predominant carbapenemase type in Enterobacteriaceae in many countries. However, not all OXA-48 variants possess significant activity toward carbapenems (e.g., OXA-163). Two Serratia marcescens isolates with resistance either to carbapenems or to extended-spectrum cephalosporins were successively recovered from the same patient. A genomic comparison using pulsed-field gel electrophoresis and automated Rep-PCR typing identified a 97.8% similarity between the two isolates. Both strains were resistant to penicillins and first-generation cephalosporins. The first isolate was susceptible to expanded-spectrum cephalosporins, was resistant to carbapenems, and had a significant carbapenemase activity (positive Carba NP test) related to the expression of OXA-48. The second isolate was resistant to expanded-spectrum cephalosporins, was susceptible to carbapenems, and did not express a significant imipenemase activity, (negative for the Carba NP test) despite possessing a blaOXA-48-type gene. Sequencing identified a novel OXA-48-type β-lactamase, OXA-405, with a four-amino-acid deletion compared to OXA-48. The blaOXA-405 gene was located on a ca. 46-kb plasmid identical to the prototype IncL/M blaOXA-48-carrying plasmid except for a ca. 16.4-kb deletion in the tra operon, leading to the suppression of self-conjugation properties. Biochemical analysis showed that OXA-405 has clavulanic acid-inhibited activity toward expanded-spectrum activity without significant imipenemase activity. This is the first identification of a successive switch of catalytic activity in OXA-48-like β-lactamases, suggesting their plasticity. Therefore, this report suggests that the first-line screening of carbapenemase producers in Enterobacteriaceae may be based on the biochemical detection of carbapenemase activity in clinical settings.
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King DT, King AM, Lal SM, Wright GD, Strynadka NCJ. Molecular Mechanism of Avibactam-Mediated β-Lactamase Inhibition. ACS Infect Dis 2015; 1:175-84. [PMID: 27622530 DOI: 10.1021/acsinfecdis.5b00007] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Emerging β-lactamase-mediated resistance is threatening the clinical utility of the single most prominent class of antibacterial agents used in medicine, the β-lactams. The diazabicyclooctane avibactam is able to inhibit a wider range of serine β-lactamases than has been previously observed with β-lactamase inhibitors such as the widely prescribed clavulanic acid. However, despite its broad-spectrum activity, variable levels of inhibition have been observed for molecular class D β-lactamases. In order to better understand the molecular basis and spectrum of inhibition by avibactam, we provide structural and mechanistic analysis of the compound in complex with important class A and D serine β-lactamases. Herein, we reveal the 1.7- and 2.0-Å-resolution crystal structures of avibactam covalently bound to class D β-lactamases OXA-10 and OXA-48. Furthermore, a kinetic analysis of key active-site mutants for class A β-lactamase CTX-M-15 allows us to propose a validated mechanism for avibactam-mediated β-lactamase inhibition including a unique role for S130, which acts as a general base. This study provides molecular insights that will aid in the design and development of avibactam-based chemotherapeutic agents effective against emerging drug-resistant microorganisms.
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Affiliation(s)
- Dustin T. King
- The Department of Biochemistry and Molecular
Biology and Center for Blood Research, University of British Columbia, 2350 Health Sciences Mall, Vancouver, British Columbia V6T 1Z3, Canada
| | - Andrew M. King
- M.
G. Department of Biochemistry and Biomedical Sciences and the Department
of Chemistry, DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario L8S
4K1, Canada
| | - Sarah M. Lal
- M.
G. Department of Biochemistry and Biomedical Sciences and the Department
of Chemistry, DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario L8S
4K1, Canada
| | - Gerard D. Wright
- M.
G. Department of Biochemistry and Biomedical Sciences and the Department
of Chemistry, DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario L8S
4K1, Canada
| | - Natalie C. J. Strynadka
- The Department of Biochemistry and Molecular
Biology and Center for Blood Research, University of British Columbia, 2350 Health Sciences Mall, Vancouver, British Columbia V6T 1Z3, Canada
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Sahuquillo-Arce JM, Hernández-Cabezas A, Yarad-Auad F, Ibáñez-Martínez E, Falomir-Salcedo P, Ruiz-Gaitán A. Carbapenemases: A worldwide threat to antimicrobial therapy. World J Pharmacol 2015; 4:75-95. [DOI: 10.5497/wjp.v4.i1.75] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 11/07/2014] [Accepted: 12/01/2014] [Indexed: 02/07/2023] Open
Abstract
Carbapenems are potent β-lactams with activity against extended-spectrum cephalosporinases and β-lactamases. These antibiotics, derived from thienamycn, a carbapenem produced by the environmental bacterium Streptomyces cattleya, were initially used as last-resort treatments for severe Gram-negative bacterial infections presenting resistance to most β-lactams but have become an empirical option in countries with high prevalence of Extended Spectrum β-lactamase-producing bacterial infections. Imipenem, the first commercially available carbapenem, was approved for clinical use in 1985. Since then, a wide variety of carbapenem-resistant bacteria has appeared, primarily Enterobacteriaceae such as Escherichia coli or Klebsiella pneumoniae (K. pneumoniae), Pseudomonas aeruginosa and Acinetobacter baumannii, presenting different resistance mechanisms. The most relevant mechanism is the production of carbapenem-hydrolyzing β-lactamases, also known as carbapenemases. These enzymes also inactivate all known β-lactams, and some of these enzymes can be acquired through horizontal gene transfer. Moreover, plasmids, transposons and integrons harboring these genes typically carry other resistance determinants, rendering the recipient bacteria resistant to almost all currently used antimicrobials, as is the case for K. pneumoniae carbapenemase - or New Delhi metallo-β-lactamases-type enzymes. The recent advent of these enzymes in the health landscape presents a serious challenge. First, the emergence of carbapenemases limits the currently available treatment options; second, these enzymes pose a risk to patients, as some studies have demonstrated high mortality associated with carbapenemase-producing bacterial infections; and third, these circumstances require an extra cost to sanitary systems, which are particularly cumbersome in developing countries. Therefore, emphasis should be placed on the early detection of these enzymes, the prevention of the spread of carbapenemase-producing bacteria and the development of new drugs resistant to carbapenemase hydrolysis.
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45
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Mitchell JM, Clasman JR, June CM, Kaitany KCJ, LaFleur JR, Taracila MA, Klinger NV, Bonomo RA, Wymore T, Szarecka A, Powers RA, Leonard DA. Structural basis of activity against aztreonam and extended spectrum cephalosporins for two carbapenem-hydrolyzing class D β-lactamases from Acinetobacter baumannii. Biochemistry 2015; 54:1976-87. [PMID: 25710192 DOI: 10.1021/bi501547k] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The carbapenem-hydrolyzing class D β-lactamases OXA-23 and OXA-24/40 have emerged worldwide as causative agents for β-lactam antibiotic resistance in Acinetobacter species. Many variants of these enzymes have appeared clinically, including OXA-160 and OXA-225, which both contain a P → S substitution at homologous positions in the OXA-24/40 and OXA-23 backgrounds, respectively. We purified OXA-160 and OXA-225 and used steady-state kinetic analysis to compare the substrate profiles of these variants to their parental enzymes, OXA-24/40 and OXA-23. OXA-160 and OXA-225 possess greatly enhanced hydrolytic activities against aztreonam, ceftazidime, cefotaxime, and ceftriaxone when compared to OXA-24/40 and OXA-23. These enhanced activities are the result of much lower Km values, suggesting that the P → S substitution enhances the binding affinity of these drugs. We have determined the structures of the acylated forms of OXA-160 (with ceftazidime and aztreonam) and OXA-225 (ceftazidime). These structures show that the R1 oxyimino side-chain of these drugs occupies a space near the β5-β6 loop and the omega loop of the enzymes. The P → S substitution found in OXA-160 and OXA-225 results in a deviation of the β5-β6 loop, relieving the steric clash with the R1 side-chain carboxypropyl group of aztreonam and ceftazidime. These results reveal worrying trends in the enhancement of substrate spectrum of class D β-lactamases but may also provide a map for β-lactam improvement.
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Affiliation(s)
| | | | | | | | | | - Magdalena A Taracila
- ∥Departments of Medicine, Pharmacology, Biochemistry, and Molecular Biology and Microbiology, Case Western Reserve University and Research Service, and Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, Ohio 44106, United States
| | | | - Robert A Bonomo
- ∥Departments of Medicine, Pharmacology, Biochemistry, and Molecular Biology and Microbiology, Case Western Reserve University and Research Service, and Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, Ohio 44106, United States
| | - Troy Wymore
- ⊥UT/ORNL Center for Molecular Biophysics, Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
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Lahiri SD, Mangani S, Jahić H, Benvenuti M, Durand-Reville TF, De Luca F, Ehmann DE, Rossolini GM, Alm RA, Docquier JD. Molecular basis of selective inhibition and slow reversibility of avibactam against class D carbapenemases: a structure-guided study of OXA-24 and OXA-48. ACS Chem Biol 2015; 10:591-600. [PMID: 25406838 DOI: 10.1021/cb500703p] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The Class D (or OXA-type) β-lactamases have expanded to be the most diverse group of serine β-lactamases with a highly heterogeneous β-lactam hydrolysis profile and are typically resistant to marketed β-lactamase inhibitors. Class D enzymes are increasingly found in multidrug resistant (MDR) Acinetobacter baumannii, Pseudomonas aeruginosa, and various species of the Enterobacteriaceae and are posing a serious threat to the clinical utility of β-lactams including the carbapenems, which are typically reserved as the drugs of last resort. Avibactam, a novel non-β-lactam β-lactamase inhibitor, not only inhibits all class A and class C β-lactamases but also has the promise of inhibition of certain OXA enzymes, thus extending the antibacterial activity of the β-lactam used in combination to the organisms that produce these enzymes. X-ray structures of OXA-24 and OXA-48 in complex with avibactam revealed the binding mode of this inhibitor in this diverse class of enzymes and provides a rationale for selective inhibition of OXA-48 members. Additionally, various subunits of the OXA-48 structure in the asymmetric unit provide snapshots of different states of the inhibited enzyme. Overall, these data provide the first structural evidence of the exceptionally slow reversibility observed with avibactam in class D β-lactamases. Mechanisms for acylation and deacylation of avibactam by class D enzymes are proposed, and the likely extent of inhibition of class D β-lactamases by avibactam is discussed.
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Affiliation(s)
| | | | | | | | | | | | | | - Gian Maria Rossolini
- Department of Experimental and Clinical
Medicine, University of Florence, Florence I-50134, Italy
- Clinical
Microbiology and Virology Unit, Florence Careggi University Hospital, Florence I-50134, Italy
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47
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Affiliation(s)
- Bettina M. Nestl
- Institute
of Technical Biochemistry, University of Stuttgart, Allmandring
31, 70569 Stuttgart, Germany
| | - Bernhard Hauer
- Institute
of Technical Biochemistry, University of Stuttgart, Allmandring
31, 70569 Stuttgart, Germany
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48
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June CM, Vaughan RM, Ulberg LS, Bonomo RA, Witucki LA, Leonard DA. A fluorescent carbapenem for structure function studies of penicillin-binding proteins, β-lactamases, and β-lactam sensors. Anal Biochem 2014; 463:70-4. [PMID: 25058926 DOI: 10.1016/j.ab.2014.07.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Accepted: 07/12/2014] [Indexed: 11/29/2022]
Abstract
By reacting fluorescein isothiocyanate with meropenem, we have prepared a carbapenem-based fluorescent β-lactam. Fluorescein-meropenem binds both penicillin-binding proteins and β-lactam sensors and undergoes a typical acylation reaction in the active site of these proteins. The probe binds the class D carbapenemase OXA-24/40 with close to the same affinity as meropenem and undergoes a complete catalytic hydrolysis reaction. The visible light excitation and strong emission of fluorescein render this molecule a useful structure-function probe through its application in sodium dodecyl sulfate-polyacrylamide gel electrophoresis assays as well as solution-based kinetic anisotropy assays. Its classification as a carbapenem β-lactam and the position of its fluorescent modification render it a useful complement to other fluorescent β-lactams, most notably Bocillin FL. In this study, we show the utility of fluorescein-meropenem by using it to detect mutants of OXA-24/40 that arrest at the acyl-intermediate state with carbapenem substrates but maintain catalytic competency with penicillin substrates.
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Affiliation(s)
- Cynthia M June
- Department of Chemistry, Grand Valley State University, Allendale, MI 49401, USA
| | - Robert M Vaughan
- Department of Chemistry, Grand Valley State University, Allendale, MI 49401, USA
| | - Lucas S Ulberg
- Department of Chemistry, Grand Valley State University, Allendale, MI 49401, USA
| | - Robert A Bonomo
- Research Service, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, and Department of Pharmacology, Molecular Biology, and Microbiology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Laurie A Witucki
- Department of Chemistry, Grand Valley State University, Allendale, MI 49401, USA
| | - David A Leonard
- Department of Chemistry, Grand Valley State University, Allendale, MI 49401, USA.
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49
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Abstract
Carbapenem-hydrolyzing class D β-lactamases (CHDLs) are enzymes of the utmost clinical importance due to their ability to produce resistance to carbapenems, the antibiotics of last resort for the treatment of various life-threatening infections. The vast majority of these enzymes have been identified in Acinetobacter spp., notably in Acinetobacter baumannii. The OXA-2 and OXA-10 enzymes predominantly occur in Pseudomonas aeruginosa and are currently classified as narrow-spectrum class D β-lactamases. Here we demonstrate that when OXA-2 and OXA-10 are expressed in Escherichia coli strain JM83, they produce a narrow-spectrum antibiotic resistance pattern. When the enzymes are expressed in A. baumannii ATCC 17978, however, they behave as extended-spectrum β-lactamases and confer resistance to carbapenem antibiotics. Kinetic studies of OXA-2 and OXA-10 with four carbapenems have demonstrated that their catalytic efficiencies with these antibiotics are in the same range as those of some recognized class D carbapenemases. These results are in disagreement with the classification of the OXA-2 and OXA-10 enzymes as narrow-spectrum β-lactamases, and they suggest that other class D enzymes that are currently regarded as noncarbapenemases may in fact be CHDLs.
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50
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Leonard DA, Bonomo RA, Powers RA. Class D β-lactamases: a reappraisal after five decades. Acc Chem Res 2013; 46:2407-15. [PMID: 23902256 DOI: 10.1021/ar300327a] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Despite 70 years of clinical use, β-lactam antibiotics still remain at the forefront of antimicrobial chemotherapy. The major challenge to these life-saving therapeutics is the presence of bacterial enzymes (i.e., β-lactamases) that can hydrolyze the β-lactam bond and inactivate the antibiotic. These enzymes can be grouped into four classes (A-D). Among the most genetically diverse are the class D β-lactamases. In this class are β-lactamases that can inactivate the entire spectrum of β-lactam antibiotics (penicillins, cephalosporins, and carbapenems). Class D β-lactamases are mostly found in Gram-negative bacteria such as Pseudomonas aeruginosa , Escherichia coli , Proteus mirabilis , and Acinetobacter baumannii . The active-sites of class D β-lactamases contain an unusual N-carboxylated lysine post-translational modification. A strongly hydrophobic active-site helps create the conditions that allow the lysine to combine with CO2, and the resulting carbamate is stabilized by a number of hydrogen bonds. The carboxy-lysine plays a symmetric role in the reaction, serving as a general base to activate the serine nucleophile in the acylation reaction, and the deacylating water in the second step. There are more than 250 class D β-lactamases described, and the full set of variants shows remarkable diversity with regard to substrate binding and turnover. Narrow-spectrum variants are most effective against the earliest generation penicillins and cephalosporins such as ampicillin and cephalothin. Extended-spectrum variants (also known as extended-spectrum β-lactamases, ESBLs) pose a more dangerous clinical threat as they possess a small number of substitutions that allow them to bind and hydrolyze later generation cephalosporins that contain bulkier side-chain constituents (e.g., cefotaxime, ceftazidime, and cefepime). Mutations that permit this versatility seem to cluster in the area surrounding an active-site tryptophan resulting in a widened active-site to accommodate the oxyimino side-chains of these cephalosporins. More concerning are the class D β-lactamases that hydrolyze clinically important carbapenem β-lactam drugs (e.g., imipenem). Whereas carbapenems irreversibly acylate and inhibit narrow-spectrum β-lactamases, class D carbapenemases are able to recruit and activate a deacylating water. The rotational orientation of the C6 hydroxyethyl group found on all carbapenem antibiotics likely plays a role in whether the deacylating water is effective or not. Inhibition of class D β-lactamases is a current challenge. Commercially available inhibitors that are active against other classes of β-lactamases are ineffective against class D enzymes. On the horizon are several compounds, consisting of both β-lactam derivatives and non-β-lactams, that have the potential of providing novel leads to design new mechanism-based inactivators that are effective against the class D enzymes. Several act synergistically when given in combination with a β-lactam antibiotic, and others show a unique mechanism of inhibition that is distinct from the traditional β-lactamase inhibitors. These studies will bolster structure-based inhibitor design efforts to facilitate the optimization and development of these compounds as class D inactivators.
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Affiliation(s)
- David A. Leonard
- Department of Chemistry, Grand Valley State University, Allendale, Michigan 49401, United States
| | - Robert A. Bonomo
- Research Service, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, and Department of Pharmacology, Molecular Biology and Microbiology, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106, United States
| | - Rachel A. Powers
- Department of Chemistry, Grand Valley State University, Allendale, Michigan 49401, United States
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