Metallo-β-lactamase (MBL) project: From molecular biology to the development of an

MBL-inhibitor

Indo-Norwegian Workshop on Antimicrobial Resistance Tromsø, Norway

26-27th of September 2013

Ørjan Samuelsen Reference Centre for Detection of Antimicrobial Resistance

Dept. of Microbiology and Infection Control University Hospital of North Norway

Tromsø, Norway

Pharma – withdrawn from development of antibiotics

Cost of development

Restricted use

Undervalued/underpriced

Emergence of resistance

New antibiotics or inhibitors of resistance mechanisms are urgently needed!

BACKGROUND

BACKGROUND: CARBAPENEMASES

• Carbapenemase: β-lactamases that inactivates carbapenems

Serine β-lactamases Metallo-β-lactamases (MBLs)

Class A Class D Class B

β-lactam substrates β-lactamase inhibitors

Mo

lecu

lar

clas

s

β-l

acta

mas

es

Pen

icill

ins

1st

, 2n

d g

en

. ce

ph

alo

spo

rin

s

3rd

, 4th

ge

n.

cep

hal

osp

ori

ns

Mo

no

bac

tam

s

Car

bap

enem

s

Inhibited by:

A KPCs + + + + + Boronic acid

(clavulanic acid, tazobactam)

D OXA-48’s: + + - - + NaCl

B MBLs, + + + - + EDTA/Dipicolinic acid

BACKGROUND: THE EMERGENCE OF CARBAPENEMASES IN GRAM-NEGATIVE PATHOGENS

• Major carbapenemases:

– Class A: KPC

– Class B (MBLs): NDM, VIM, IMP

– Class D: OXA-carbapenemases

• Enterobacteriaceae, P. aeruginosa and A. baumannii

• →Co-resistance

– Aminoglycosides, Fluoroquinolones, Trimethoprim-sulphamethoxazole etc.

BACKGROUND: GLOBAL DISSEMINATION

KPC OXA-48’s

VIM & NDM

BACKGROUND: RAPID GLOBAL DISSEMINATION

• Example: New Dehli Metallo-β-Lactamase (NDM)

• Sweden (India) 2008: K. pneumoniae

• Retrospective analysis: 2006 India

• >40 countries • “Promiscuous” plasmids

• Diversity of clones

MBL PROJECT IN TROMSØ

• Collaboration between microbiologists, biochemists, crystallographers and chemists

• Collaborators: – Institute of Pharmacy

– Dept. of Chemistry

– MarBio/MabCent

– International collaborators

National Reference Centre for Detection of Antimicrobial Resistance

Norwegian Structural Biology Centre

National Reference Centre for Detection of Antimicrobial Resistance (K-res)

• Dept. of Microbiology and Infection Control

• Close collaboration with research groups at UiT

• Main funding: Ministry of Health

– 4,2 positions (20% M.D., 2 scientists, 2 technicians)

• Primary objectives:

– Phenotypic & molecular analysis

– Competence building

– Research

NATIONAL REFERENCE CENTRE FOR DETECTION OF ANTIMICROBIAL RESISTANCE (K-res)

• Research

Molecular epidemiology

Treatment options

Basic research on

antimicrobial resistance

Method development/

evaluation

New antimicrobial

strategies

NORWEGIAN STRUCTURAL BIOLOGY CENTRE (NORSTRUCT)

• National research and service centre

• State of the art instrumentation from protein production through high throughput crystallization and structure determination to drug discovery related tasks.

MBL PROJECT: RESEARCH ACTIVITIES

Molecular biology

Drug Discovery

Novel MBL inhibitor

MBL PROJECT: MOLECULAR BIOLOGY RESEARCH

• Protein production

• Biochemical characterization

• Crystallization & structure determination

• Molecular modelling/docking studies

MBL PROJECT: MOLECULAR BIOLOGY RESEARCH

• Biochemical characterization: – TMB-1, VIM-7-mutants, VIM-26, AIM-1-mutants, GIM-1-mutants

• Docking & QM/MM calculations:

VIM-7 AIM-1 GIM-1 VIM-26

MBL PROJECT: DRUG DISCOVERY

Marine extracts

Chemical compounds

VIM

~3000 marine extracts screened ~40 synthesized chemical compounds

MBL PROJECT: POTENTIAL RESEARCH TOPICS

• Molecular biology:

– Characterization of novel carbapenemases

• Drug discovery:

– β-lactamase inhibitors

– Screening of chemical compounds

– Chemical synthesis

Hanna-Kirsti S. Leiros, Annette Bayer, Susann Skagseth, Bjarte Aarmo Lund, Gro Bjerga, Tony Christopheit, Trine Josefine Olsen Carlsen, Arne Smalås

Ørjan Samuelsen, Arnfinn Sundsfjord

Pål Rognved, Ove Alexander Åstrand

James Spencer

Timothy Walsh

Rafi Ahmad